Diseases for which vaccinations are available in Estonia

What is hepatitis A?

It is an inflammation of the liver, also known as jaundice. The cause of the disease is infection with the hepatitis A virus (HAV), which replicates in liver tissue and damages it. There is no specific treatment for hepatitis A.

How is it diagnosed?

The diagnosis is based on clinical presentation, epidemiological data (close contact with an infected person or travel to areas with high HAV prevalence), and laboratory tests.

How does it spread?

The hepatitis A virus spreads via the fecal-oral route, either directly from one person to another (e.g., among diapered children in daycare) or through contaminated food and water. The virus can also spread through anal sex and, in rare cases, through blood.

HAV is a resilient virus that can survive for days in both food and salt water.

Baked goods and other foods prepared by infected individuals that do not require further heating have caused several outbreaks.

Widespread illness has also been caused by the consumption of raw oysters, shellfish, mollusks, and crustaceans, as these may come into contact with the virus through sewage water while growing in coastal areas near cities.

Infection can also occur from ice made from virus-contaminated water, such as ice served in beverages.

Course of the Disease

A key characteristic of hepatitis A is the presence of latent or asymptomatic forms, particularly in children.

The disease has several stages:

• Incubation period typically lasts 28–30 days. During this time, there are no visible symptoms, although the virus is actively replicating in the body. The period is shorter the more virus that entered the body.
• The prodromal phase lasts an average of 5–7 days and ends with the onset of jaundice. The patient may experience fever, loss of appetite, muscle aches, vomiting, weakness, and other symptoms.
• Jaundice (or icterus), indicated by yellowish-brown urine, which is caused by high levels of bilirubin in the blood. After a few days, the patient’s skin turns yellow. It is typically during this phase that patients seek medical attention. During this period, the patient remains contagious for about one week.
• The recovery period lasts up to a couple of months.

Symptoms may appear 15–50 days after exposure to the virus. An infected person is contagious 2–3 weeks before the first symptoms appear and during the first and second weeks of the illness.

Typically, a person recovers within a few months without complications. In 3–20% of cases, hepatitis A can recur. This occurs 4–15 weeks after symptoms have disappeared.

After recovering from hepatitis A, lifelong immunity develops.

Kuidas levib?

A-hepatiidi viirus levib fekaal-oraalsel teel kas otse ühelt inimeselt teisele (nt mähkmeid kandvate laste vahel lasteaias) või saastunud toidu ja vee kaudu. Viirus võib levida ka anaalseksi ning harvadel juhtudel vere kaudu.

HAV on vastupidav viirus, mis säilib päevi nii toiduainetes kui ka soolases vees.

Viirusega nakatunud inimeste valmistatud kondiitritooted ja teised toiduained, mis hilisemat kuumutamist ei vaja, on põhjustanud mitmeid haiguspuhanguid.

Laialdast haigestumist on kaasa toonud ka toorelt tarvitatavate austrite, koorikloomade, limuste ja vähiliste söömine, sest need võivad linnalähedases rannas kasvades viirusega kokku puutuda kanalisatsioonivee kaudu.

Samuti võib nakatuda viirusega saastunud veest tehtud jääst, mida serveeritakse näiteks joogis.

Haiguse kulg

A-viirushepatiidi oluline iseärasus on varjatud või ilma nähtavate tunnusteta vormide esinemine, eriti lastel.

Haigusel on mitu perioodi:

• Peiteperiood kestab tavaliselt 28–30 päeva. Sel ajal puuduvad nähtavad tunnused, kuigi viirus paljuneb organismis aktiivselt. Periood on seda lühem, mida rohkem viirust organismi sattus.
• Eelnähtude faas kestab keskmiselt 5–7 päeva ja lõpeb kollatõve tekkega. Patsiendil võivad olla palavik, isutus, lihasvalud, oksendamine, nõrkus jm haigusnähud.
• Kollatõbi (ehk ikterus), millest annab märku kollakaspruun uriin, mis on tingitud vere suurest bilirubiini sisaldusest. Paari päeva pärast muutub patsiendi nahk kollaseks. Just selles faasis pöördutakse tavaliselt arsti poole. Sel perioodil on haige nakkusohtlik umbes ühe nädala jooksul.
• Paranemisperiood kestab kuni paar kuud.

Sümptomid võivad tekkida 15–50 päeva pärast kokkupuudet viirusega. Haige inimene on nakkusohtlik 2–3 nädalat enne esimeste haigusnähtude tekkimist ning haiguse esimesel ja teisel nädalal.

Tavaliselt paraneb inimene mõne kuuga ja ilma tüsistusteta. 3–20% juhtudest võib A-viirushepatiit taas ägeneda. See toimub 4–15 nädalat pärast haigusnähtude kadumist.

Pärast A-viirushepatiidi läbipõdemist kujuneb eluaegne immuunsus.

What is hepatitis B?

It is an inflammation of the liver caused by the hepatitis B virus (HBV). Chronic hepatitis B can lead to cirrhosis or liver cancer.

How is it diagnosed?

Hepatitis B is diagnosed based on blood tests and clinical symptoms.

How does it spread?

The hepatitis B virus is highly contagious and spreads:

• through blood transfusions, reuse of syringes, tattooing, piercing, puncture wounds, microtrauma, or use of blood-contaminated personal items (toothbrushes, razors);
• from mother to newborn;
• through sexual contact.

HBV is highly resistant, remaining viable when frozen at –15 °C for up to 15 years and at temperatures between +30 and +32 °C for at least 6 months. The virus also withstands brief boiling. To destroy HBV, potent disinfectants must be used.

A person infected with the virus is contagious several weeks before symptoms appear and during the course of the illness. Patients with chronic hepatitis B are also contagious.

Course of the disease

As with hepatitis A, a key characteristic of hepatitis B is that the disease can occur without visible symptoms. Nearly one-third of adults experience the disease asymptomatically; after recovery, there is a high risk of becoming a chronic carrier of the virus.

The incubation period for hepatitis B can last 30–180 days (on average 60–90 days).

The acute phase of the disease has three stages:

• Preliminary symptoms last an average of 2–7 days. Fatigue, loss of appetite, fever, bloating, and pain in the liver area may occur. At the end of this stage, urine becomes dark and stools become pale.
• Symptoms of the disease last 4–8 weeks. Yellowing of the skin and mucous membranes (in 25% of patients) and itchy skin may occur. During the acute phase of the disease, only the symptoms are treated.
• Recovery takes 2–6 months, after which normal well-being returns.

Hepatitis B can cause chronic liver inflammation. The younger the infected person, the greater the risk. While 5–10% of adults who have had the acute form develop chronic disease, the risk is much higher in children (up to 90% of infected newborns develop chronic liver disease for life).

In the case of chronic hepatitis B, the goal of treatment is to reduce the extent of liver inflammation or damage. Complete elimination of the virus is no longer possible.

Who is at higher risk of infection?

• Newborns whose mothers are infected with the hepatitis B virus.
• Sexual partners of infected individuals.
• People who frequently change sexual partners.
• People who engage in anal sex.
• Injecting drug users.
• Family members and other close contacts of people with chronic hepatitis B.
• Patients and staff in long-term care facilities.
• Healthcare workers who come into contact with blood and other bodily fluids.
• Patients undergoing hemodialysis and peritoneal dialysis.
• Travelers to countries with high rates of hepatitis B.
• Users of skin-piercing beauty services (tattooing, piercing).

How to avoid getting sick?

• Avoid using other people’s hygiene items, especially toothbrushes, razors, and manicure tools.
• Use condoms during sexual intercourse.
• Avoid contact with unsterilized or unsanitized medical instruments and beauty service tools.
• People who come into contact with blood and other bodily fluids due to their work (healthcare and emergency service workers, police officers, prison staff, military personnel, etc.) must strictly follow hygiene rules.
• Avoid reusing syringes and needles.

Illness can be prevented through vaccination, which provides long-term and effective protection.

What is COVID-19?

COVID-19 (Coronavirus Disease 2019) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In most cases, the disease presents with mild symptoms characteristic of the common cold, but the virus can also cause breathing difficulties and pneumonia.

How is it diagnosed?

To detect infection with the virus, viral RNA is tested. For this, a sample is usually taken from the nose or nasopharynx using a swab. The test allows for detection of the infection at an early stage. This helps to act quickly and, if necessary, go into quarantine immediately to limit the spread of the virus. A PCR test is used to detect viral RNA. This is an accurate laboratory method that requires specialized equipment, trained laboratory staff, and a laboratory process adapted for this purpose.

How does it spread?

The virus spreads from an infected person through respiratory droplets when coughing, sneezing, or exhaling. Infection can also occur if you touch your mouth, eyes, or nose with contaminated hands after touching contaminated surfaces.

Symptoms

Most often, symptoms similar to those of a cold or the flu develop. The main ones include headache, nasal congestion, cough, fatigue and weakness, muscle aches, runny nose, sore throat, fever, and possible loss of smell and taste. In more severe cases, breathing difficulties, chest pain, and speech and movement disorders may occur.

What is diphtheria?

Diphtheria is a serious bacterial disease that manifests as inflammation of the throat, larynx, and nose. The disease can be fatal.

How is it diagnosed?

The disease is generally identified based on external symptoms. If diphtheria is suspected, a swab sample is taken from the back of the nose to test for the presence of the pathogen. Additionally, diphtheria can be diagnosed by detecting antibodies in the blood.

How does it spread?

Diphtheria spreads through direct person-to-person contact, as well as through droplet transmission when coughing or sneezing. The disease usually affects the upper respiratory tract or the skin, and less commonly the mucous membranes of the eyes or genitals.

People of any age can contract diphtheria. The pathogen usually enters the body through the mucous membranes of the upper respiratory tract and multiplies there. A pus-like fluid is secreted from the infected tissue, forming a membrane-like coating.

If diphtheria is suspected, the patient must be hospitalized immediately, and the health of people who have been in contact with them must be monitored. Without treatment, an infected person can spread the disease for 2–3 weeks.

Course of the disease

The disease begins with a pseudomembranous tonsillitis, which can spread to the rest of the respiratory tract. The pseudomembranes are grayish, whitish, or dark due to bleeding, and extend beyond the edge of the tonsils. If the coating spreads to the larynx, trachea, and bronchi, airway obstruction may occur. Children are particularly at risk, as they may develop laryngeal edema and suffocation in such cases.

Complications may affect the kidneys, heart, and nervous system. Paralysis of the oral muscles and pneumonia may also occur.

The following symptoms are characteristic of diphtheria:

• swollen lymph nodes,
• sore throat,
• loss of voice,
• cough,
• shortness of breath,
• difficulty swallowing.

The incubation period usually lasts 2 to 5 days.

One day after starting antibiotic treatment, the patient is generally no longer contagious.

Recovering from diphtheria does not confer protective immunity.

What is the flu?

The flu is a viral illness characterized by a sudden onset of illness and a high fever (38 °C and above), accompanied by either a cough, headache, sore throat, or muscle aches, or difficulty breathing.

Learn more about the flu.

How is it diagnosed?

The illness is usually identified based on external symptoms and/or by taking a swab sample from the back of the nose to test for the presence of the pathogen. If necessary, more specific rapid tests are also used.

How does it spread?

The virus usually spreads through droplets released when sneezing, blowing one’s nose, or coughing. If hands are not washed, the virus can end up on many surfaces, such as doorknobs, door handles, phones, and computer keyboards.

Haiguse kulg

Gripi peiteperiood on keskmiselt 3–7 päeva. Nakkusohtlikuks muutub inimene päev enne sümptomite ilmumist ning nakkavuse periood kestab kuni 7 päeva (väikelastel kuni 21 päeva).

Gripi tunnus on haiguse äkiline algus kõrge palavikuga (38 °C ja üle selle), millele lisanduvad kas köha, peavalu, kurgu- või lihasvalu või ka hingamisraskused. Võib esineda ka kõhulahtisust.

Gripi puhul on kõige kardetumad tüsistused ninakõrvakoobaste põletik, neelupõletik, keskkõrvapõletik, bronhiit või kopsupõletik. Gripi tüsistused võivad lõppeda surmaga.

Course of the disease

The incubation period for the flu is 3–7 days on average. A person becomes contagious one day before symptoms appear, and the contagious period lasts up to 7 days (up to 21 days in young children).

A hallmark of the flu is the sudden onset of the illness with a high fever (38 °C and above), accompanied by either a cough, headache, sore throat, or muscle aches, or difficulty breathing. Diarrhea may also occur.

The most feared complications of the flu are sinusitis, pharyngitis, otitis media, bronchitis, or pneumonia. Complications of the flu can be fatal.

Who is at higher risk of infection?

The following risk groups should seriously consider vaccination:

• recipients of general and specialized care services (24-hour care and community living),
• people over 60,
• pregnant women,
• children up to 7 years of age,
• people in the flu risk group due to health conditions,
• people at risk through their work (healthcare workers, care facility staff, poultry farm workers, etc.),
• people who may spread the flu to the risk group.

Vaccination is contraindicated in cases of hypersensitivity to egg protein or any other component of the vaccine, as well as during an acute febrile illness.

Information on vaccines used in Estonia can be found on the State Agency of Medicines website.

What is Haemophilus influenzae type b, or Hib infection?

Hib infection is a cause of purulent meningitis in infants and young children.

How is it diagnosed?

To diagnose Hib infection, blood, sputum, or other samples are tested to determine whether the pathogen is present in the body.

How does it spread?

The source of infection is a sick person or a carrier of the pathogen. The Haemophilus bacterium spreads through droplet transmission only from person to person (e.g., by coughing or sneezing). The disease can also be transmitted by people who show no symptoms.

Symptoms

Every newborn receives Hib antibodies from the mother via the placenta, but unfortunately, these disappear within the first few months of life. The highest risk of infection lies with children aged 4–24 months, and the risk remains high until the age of 5.

The incubation period lasts an average of 2–4 days.

Haemophilus influenzae type b can cause meningitis, pneumonia, acute epiglottitis, septicemia, cellulitis, and arthritis. Different strains can cause bronchitis and otitis media. Bacterial meningitis accounts for about 50% of cases and is characterized by a sudden fever over 38 °C, headache, neck stiffness, altered consciousness, nausea, and vomiting.

Complications of Hib infection may include hearing loss or deafness, delayed mental development, or persistent seizure syndrome.

What is human papillomavirus?

Human papillomavirus (HPV) infection is very widespread, and a large proportion of people become infected with some strain of HPV during their lifetime. Most HPV types cause benign changes on the skin (e.g., warts) and mucous membranes (e.g., genital warts). Some types of papillomavirus can cause the development of malignant tumors in the genital area (e.g., cervical, vulvar, vaginal, anal, and penile cancer, as well as precancerous conditions) and in the oral cavity (e.g., oral and throat cancer).

Learn more about HPV.

How is it diagnosed?

To diagnose human papillomavirus infection, women undergo an HPV test or Pap test taken from the cervix, while men provide a sample from the foreskin.

In Estonia, the HPV test is used for cervical cancer screening. Women aged 30–65 are invited for screening every five years. Read more about cancer screenings.

How does it spread?

Human papillomaviruses are spread through direct contact with the skin or mucous membranes of an infected person. Infection can occur as early as the first sexual encounter.

Course of the disease

The incubation period for the papillomavirus varies from a few months to several years. The virus can cause changes in the mucous membranes, skin lesions, condylomas, precancerous conditions, and malignant tumors. It usually takes more than 15 years from infection to the development of cancer.

What is Japanese encephalitis?

Japanese encephalitis is a viral disease that can cause high fever, meningitis (inflammation of the meninges), and encephalitis (inflammation of the brain).

How is it diagnosed?

Japanese encephalitis is diagnosed based on epidemiological data (prolonged stay in an area with a high prevalence of Japanese encephalitis) and laboratory tests.

How does it spread?

The virus is spread by mosquitoes in endemic regions (Asia). Japanese encephalitis therefore poses the greatest risk to people living and working in agricultural areas or marshy lands, or those visiting these regions.

Humans become infected through a mosquito bite, and the course of the disease depends on age and health status. The virus is highly resistant and survives even after 2 hours of boiling, treatment with alcohol or ether, or one year of freezing.

In the human body, the virus multiplies in the lymph nodes and enters the brain via the bloodstream. The incubation period is 4–14 days. Children up to 10 years of age are at risk. If a pregnant woman becomes infected with the virus during the first or second trimester, the pregnancy may be terminated.

Course of the disease

The disease begins acutely with fever and headache; in children, it is accompanied by nausea, vomiting, abdominal pain, and diarrhea. The illness may be limited to acute fever, but meningitis or encephalitis may also develop.

Generally, the disease is of moderate severity and the patient recovers; however, in one out of 200 cases, the disease rapidly worsens and neurological symptoms develop: paralysis, tremors, and seizures. In such cases, the disease may result in coma and death.

25–45% of survivors experience various neuropsychological sequelae.

Who is at higher risk of infection?

Vaccination is recommended for people who:

• plan to stay in an endemic area for more than a month;
• are outside of typical tourist areas;
• work in occupations that carry a high risk of infection.

Immunization against Japanese encephalitis is not necessary for the typical city tourist, but it is still recommended to consult a travel medicine physician beforehand. An inactivated vaccine is used for vaccinating adults against Japanese encephalitis. Administration of the vaccine to children and adolescents is not recommended due to a lack of data on safety and efficacy.

The vaccination series consists of two doses administered 28 days apart.

Contraindications:

• Hypersensitivity to the active ingredients of the vaccine or their residues;
• acute febrile illness (vaccination is postponed until recovery);
• hypersensitivity following the first vaccine dose.

Read more about vaccines used in Estonia on the State Agency of Medicines website.

How to avoid getting sick?

Infection can be prevented in two ways: by avoiding mosquito bites (especially in rural areas where this risk exists) or through vaccination.

To avoid mosquito bites in high-risk areas, you should:

• use a mosquito net when sleeping;
• eliminate mosquitoes in the bedroom;
• check the tightness of window and door screens, and install mosquito screens if necessary;
• when going outdoors, dress so that your entire body is covered, and use insect repellents (products containing DEET are effective).

See where are high-risk areas(Opens in new tab)north_east.

What is yellow fever?

Yellow fever is a severe acute viral infection classified as a particularly dangerous infectious disease.

How is it diagnosed?

Yellow fever is diagnosed based on epidemiological data (prolonged stay in a yellow fever-endemic area), clinical symptoms, and laboratory tests.

How does it spread?

Yellow fever is spread by mosquitoes in tropical countries.

Course of the disease

The incubation period of the virus is 3–6 days. The disease begins with a high fever and headache and back pain. Muscle aches, nausea, vomiting, and weakness follow. After about 3–5 days, a rash appears, starting on the chest and spreading to the face and limbs.

There is no specific treatment for yellow fever.

What is cholera?

Cholera is a particularly dangerous infectious disease that causes acute diarrhea and is caused by the bacterium Vibrio cholerae.

How is it diagnosed?

Cholera is diagnosed based on epidemiological data (prolonged stay in an area with high cholera prevalence) and laboratory tests.

How does it spread?

The disease spreads through the consumption of contaminated drinking water and food, as well as poor hygiene conditions. Outbreaks are often linked to the consumption of raw or undercooked seafood. Cholera outbreaks are very often associated with war or natural disasters (e.g., floods and earthquakes, which affect the purity of drinking water). The microbes that cause cholera can survive for long periods in river or seawater contaminated with human waste.

A person with the disease is usually contagious for 7–14 days. The source of infection includes people with mild symptoms, as well as those who show no symptoms despite exposure to the bacteria.

Course of the disease

The incubation period for cholera is 1–5 days, usually 2–3 days.

The illness begins with diarrhea; the stool is watery at first but turns into a rice-water-like, grayish-white liquid after a few hours. The patient begins to vomit, though nausea is often absent. Vomiting usually subsides after 18 hours, but diarrhea may persist for a longer period. Due to vomiting and diarrhea, the patient loses a significant amount of fluid. In severe cases, fluid loss can reach up to one liter per hour.

As a result of severe fluid and mineral salt loss, body temperature and blood pressure may drop, and seizures may occur. Due to dehydration, tissue volume decreases, leading to “washboard hands,” the mucous membranes become dry, and urine output decreases. The blood becomes thicker, thereby increasing the burden on the heart. This leads to microcirculatory disorders, and tissues become oxygen-deprived. Muscle weakness, cardiac arrhythmias, and abdominal distension may also occur.

What is typhoid fever?

Typhoid fever is an illness characterized by fever, abdominal pain, and a rash, caused by the Salmonella bacterium.

How is it diagnosed?

Typhoid fever is diagnosed through stool or blood samples.

How does it spread?

Typhoid fever spreads from person to person through contaminated hands, food, and water. The disease is most common in countries with poor hygiene conditions and inadequate water supplies.

Course of the disease

Typhoid fever is characterized by a prolonged fever that does not start very suddenly but rises over several days; cramping abdominal pain, a tender abdomen on palpation, and diarrhea in some patients. Weakness, loss of appetite, headache, chills, sore throat, muscle aches, and cough are characteristic. In some cases, a mild rash may appear on the abdomen and chest, and central nervous system symptoms may occur.

Typhoid fever can be fatal; the disease is particularly dangerous for children.

Possible complications of typhoid fever include inflammation of the liver, meninges, kidneys, heart muscle, joints, and salivary glands. It is very important to identify the 5% of patients who have become chronic carriers, as they can infect others for years.

What is measles?

Measles is a highly contagious viral rash disease that is widespread throughout the world. Measles can take a severe form, with common complications including pneumonia, middle ear infection, or encephalitis.

Learn more about measles.

How is it diagnosed?

Measles is diagnosed based on clinical symptoms, epidemiological data (exposure in an area where measles is circulating), and laboratory tests.

How does it spread?

The source of infection is a person who is contagious 4–5 days before and up to 2 weeks after the rash appears. The virus spreads through droplet transmission when the sick person coughs or sneezes.

Course of the disease

The incubation period lasts 7–18 (on average 10) days.

Symptoms include fever, malaise, cough, runny nose, conjunctivitis, and photophobia. After symptoms appear, white spots with a bright red border (so-called Koplik’s spots) develop on the mucous membranes of the cheeks, above the front molars. A few days later, a rash appears on the skin—it starts behind the ears and spreads to the face and neck. On the second day, the rash spreads to the body and arms, and on the third day, to the palms and soles of the feet.

The rash is pink at first and later becomes intensely red; it lasts 4–5 days and fades in the same order as it appeared. On days 6–10, the skin with the rash turns brown and begins to peel. The fever persists until the rash subsides.

The most common complications are pneumonia, middle ear infection, and encephalitis.

Infants born to women who have had measles have immunity for 6–9 months. Having had measles confers lifelong immunity.

What is whooping cough?

Whooping cough is an acute infectious disease of the respiratory tract characterized by bouts of coughing that can last for weeks or even months. Whooping cough is also known as the “100-day cough.”

How is it diagnosed?

Whooping cough is diagnosed based on clinical presentation and laboratory tests. A diagnosis can also be reached indirectly by investigating people with a cough who have been in contact with the patient.

How does it spread?

Whooping cough spreads from person to person through droplet transmission and is highly contagious during the early stages of the disease, particularly within the first two weeks.

Course of the disease

The incubation period is 5–21 days, averaging 7–10 days.

The initial symptoms of whooping cough resemble those of a cold: a runny nose, sneezing, a low-grade fever, a sore throat, and a mild cough. The cough gradually becomes more severe, and after 1–2 weeks, a characteristic, slowly intensifying paroxysmal cough develops.

Coughing fits in young children often occur at night and are typically accompanied by a whooping sound at the end of the fit. A coughing fit may also end in vomiting. In children and adults vaccinated against whooping cough, the course of the disease is milder and often atypical.

Whooping cough is particularly dangerous for infants; most deaths are associated with the disease in infants under 3 months of age. Whooping cough is one of the causes of sudden infant death syndrome.

Complications of the disease include pneumonia, convulsive syndrome, and encephalopathy (extensive disturbances in brain structure or function).

How can you prevent getting sick?

Timely vaccination of children is essential.

To limit the spread of whooping cough, direct contact with an infected person should be avoided, and the infected person must not attend childcare facilities during the 21-day contagious period or while undergoing treatment.

Immunity acquired after recovering from whooping cough is not lifelong; the disease can be contracted multiple times over the course of a lifetime. Immunity acquired after vaccination is also not lifelong; a booster shot is necessary.

The vaccine used in Estonia since 2018 provides protection not only against whooping cough but also against diphtheria, tetanus, polio, Hib infection, and hepatitis B. The first dose is given at three months of age; it takes two weeks for immunity to develop.

Vaccination recommendation for adults

• Pregnant women are recommended to be vaccinated against pertussis with the dTap vaccine during each pregnancy, preferably between the 28th and 34th weeks of pregnancy (it can be administered throughout the second and third trimesters). Vaccination induces high levels of pertussis IgG antibodies in the mother, which pass through the placenta to the fetus, providing passive immunity to the newborn for the first months of life. Since antibody levels fall to a low baseline level within a year after vaccination, revaccination is necessary during each pregnancy. The minimum interval with the previous dT vaccine is four weeks.
• Healthcare workers who have close contact with infants or pregnant women are recommended to receive the diphtheria-tetanus-pertussis (dTap) vaccine instead of the diphtheria-tetanus (dT) vaccine every 10 years.
• All adults are recommended to receive at least one vaccination with the dTap vaccine instead of the dT vaccine during adulthood. The minimum interval with the previous dT vaccine is 4 weeks.

What is rabies?

Rabies is a contagious disease in humans that affects the central nervous system; animals can also contract the disease. In animals, the disease is called rabies.

How is it diagnosed?

Rabies is primarily diagnosed based on medical history, clinical presentation, and laboratory testing.

How does it spread?

Rabies is spread through the bite or saliva of an infected animal. The virus travels along nerve trunks to the spinal cord and brain, and from there to the eyes, heart, skin, and oral cavity.

Course of the disease

The incubation period of the disease averages 1–2 months, ranging from a minimum of one week to a maximum of more than a year. The length of the incubation period depends on how far the bite from the infected animal is located from the brain.

The prodromal phase begins with nausea, vomiting, fatigue, fever, and other general symptoms. Some affected animals experience pain, inflammation, or a stinging or itching sensation in the bite area.

During the active phase of the disease, respiratory distress occurs, manifesting as deep breathing, or so-called gasping. Some patients exhibit signs of agitation and aggression, disorientation, muscle twitching, or convulsions, which cause severe pain when swallowing or even at the sight of liquid (hydrophobia, or fear of water).

Rabies can be fatal due to cardiac or respiratory arrest.

What is meningococcal infection?

Meningococcal infection is an airborne disease that spreads easily through droplets. If contracted, the disease can be fatal, depending on its severity.

How is it diagnosed?

Meningococcal infection is diagnosed based on symptoms and medical history. If necessary, a blood test is performed.

How does it spread?

Meningococcus is highly contagious. The disease spreads from person to person through droplet transmission, for example, by coughing or sneezing. The risk of infection increases with prolonged contact with a sick person or a carrier of the bacteria.

The disease is characterized by rapid and widespread transmission. Meningococcus dies fairly quickly when dried, exposed to detergents, or at temperatures below +22 °C; at +55 °C, it dies within 5 minutes.

Course of the disease

The incubation period for meningococcal infection is 2–10 days, with an average of 4–7 days. Exposure to meningococcus can result in a 2–3-week period of bacterial carriage, meaning that a person is infected and can infect others, but does not exhibit symptoms of the disease.

Typically, an acute infection with symptoms develops shortly after exposure to the bacteria. Risk factors for the disease include concurrent viral infections (acute respiratory infections, influenza), trauma, a weakened immune system, smoking, and others.

• Meningococcal meningitis symptoms include headache, high fever (up to 40 °C), vomiting, confusion, and neck stiffness. This form of the disease is usually treatable.
• Meningococcal sepsis is a severe form of the disease, as it often leads to septic shock (very low blood pressure, and tissues in the body do not receive the oxygen and nutrients necessary for normal functioning). The disease progresses rapidly, with symptoms appearing within a few hours: fever, confusion, and a rash may appear on the limbs. Mortality is high in this form.

Meningococcal infection responds to antibiotic treatment.

What is mumps?

Mumps is an acute viral infectious disease characterized by fever and painful swelling, primarily in the parotid glands, but sometimes extending to other salivary glands (submandibular and sublingual).

How is it diagnosed?

Mumps is generally diagnosed based on characteristic symptoms. Laboratory tests are performed if necessary.

How does it spread?

Mumps spreads through droplet transmission (e.g., when coughing or sneezing) and through direct contact with an infected person.

The incubation period is 11–25 days. A person with mumps spreads the virus during the last 2 days of the incubation period and, regardless of the form of the disease, from the 6th to the 9th day of illness.

People of all ages are susceptible to the virus, but children and adolescents are most commonly affected during the late winter and early spring. A mother who has had mumps passes protective antibodies to her newborn for up to a year. After recovering from mumps, lasting immunity develops.

The virus dies quickly in the external environment.

Course of the disease

Mumps has several forms of presentation. The most common is inflammation of one or both parotid glands, known as parotitis. At the onset of the disease, headaches, malaise, and loss of appetite occur over 1–2 days. This is followed by a fever of 38–39 °C; the parotid gland swells and becomes painful, initially on one side, but often on the other side as well after one or two days. The skin over the swollen gland does not become red, but remains smooth and shiny. When palpated, the swollen gland feels doughy and soft. Because the skin is tight, chewing and swallowing are difficult. Other glands (e.g., the gonads, pancreas, and thyroid) may also be affected.

One of the peculiarities of mumps is that the disease can be contracted without any symptoms.

What is pneumococcal infection?

Pneumococcal infection causes acute middle ear, sinus, or lung infections, as well as blood poisoning and meningitis.

Pneumococcal infection is diagnosed based on laboratory tests.

How does it spread?

Pneumococcus spreads from person to person mainly through droplet transmission when coughing or sneezing, as well as through objects contaminated with saliva, for example. A person who is a carrier of the bacteria but shows no symptoms can also be a source of infection.

How can you prevent getting sick?

It is important to carefully follow hygiene guidelines: wash your hands, avoid sharing personal items (including spoons and cups) with the sick person, and frequently wash shared toys. A sick child should be kept home from daycare; they may return only once they are completely healthy.

Pneumococcal infection can be prevented with vaccination, which provides protection against meningitis and sepsis caused by the disease, as well as partial protection against middle ear and lung infections.

Pneumococcal vaccination is recommended for children under 2 years of age and for people with asthma, heart disease, kidney disease, or diabetes. Vaccination is also recommended if an organ transplant, middle ear implant placement, or spleen removal is planned.

Course of the disease

In children, the most common diseases caused by pneumococcus are acute otitis media, sinusitis, and pneumonia. Bacteremia (bacterial blood poisoning), meningitis (inflammation of the meninges), sepsis (blood poisoning), and other diseases may also occur.

Acute otitis media can occur at any age, but infants between 6 months and 2 years of age are most commonly affected. The disease is characterized by severe ear pain, a sensation of pressure, hearing loss due to pus accumulating in the ear cavity, and high fever. The ear pain subsides once the pus drains from the ear through the eardrum. In children, ear pain usually begins at night while lying down. Acute otitis media is often preceded by a severe cold.

Pneumococcal pneumonia often occurs in childhood. Acute pneumonia is characterized by a sudden onset of chills, fever, and sharp pains in the affected side of the chest. This is accompanied by a painful dry cough, weakness, and headache.

Although people of any age can contract pneumococcal infection, it is more common in children under 2 years of age, the elderly, and people with immunodeficiency.

• Pneumococcal bacteremia, or bloodstream infection, occurs primarily in children under 2 years of age. Bacteremia can also occur in patients with pneumonia whose immune systems are compromised. The disease is characterized by a high fever. In most cases, bacteremia resolves without treatment, but it can also lead to pneumonia, osteomyelitis, or meningitis.
• Pneumococcal meningitis damages the meninges and the functioning of the central nervous system. Children under one year of age are most commonly affected. Symptoms of the disease include high fever, headache, neck stiffness, drowsiness, vomiting, and lethargy. Sensitivity to touch and intolerance to light and loud noises may occur. Infants may not exhibit typical symptoms, but they may be lethargic, sleep more than usual, or be overly irritable, refuse to eat, and vomit. Seizures may occur. Meningitis is often accompanied by complications, and to prevent them, it is important to diagnose the condition as quickly as possible and begin treatment in a timely manner.
• Pneumococcal sepsis is a form of blood poisoning accompanied by damage to at least one organ, such as kidney or heart failure. The patient’s body temperature may be above 38 °C or below 36 °C (hypothermia). Sepsis is a very serious condition that can lead to shock and death.

Vaccination recommendation for children

2 doses of conjugate vaccine (either PCV20, PCV15 or PCV13) at least 4 weeks apart at 6 weeks of age. 3rd dose of the same vaccine at 11–15 months of age (at least 8 weeks after the 2nd dose).

2 doses of conjugate vaccine (either PCV20, PCV15 or PCV13) at least 8 weeks apart at 12–23 months of age.

1 dose of PCV20, PCV15 or PCV13 at 2–5 years and 11 months of age.

Read more about vaccination of children.

Vaccination Recommendations for Adults

In addition to children, vaccination is recommended for:

1. Adults aged 64 and under in high-risk groups, who should receive PCV15 or PCV13 followed by PCV23 at a minimum 8-week interval, or a single dose of PCV20;
2. People aged 65 and older, who should receive PCV15 or PCV13 followed by PCV23 with a minimum interval of 1 year;
3. Adults aged 65 and older in high-risk groups, who are administered PCV15 or PCV13 followed by PPCV23 at a minimum interval of 8 weeks, and then PPCV23 or 1 dose of PCV20 at a 5-year interval.

Information on vaccines used in Estonia can be found on the State Agency of Medicines website.

What is rubella?

Rubella is a viral infectious disease that primarily affects children.

How is it diagnosed?

Rubella is diagnosed through laboratory tests.

How does it spread?

Infection occurs through person-to-person contact via respiratory droplets (e.g., coughing and sneezing). An infected person is contagious 4–7 days before and up to 2 weeks after the rash appears, with the first 5 days after the rash appears being the most contagious. Newborns with congenital rubella syndrome (the mother was infected during the first 11 weeks of pregnancy) can spread the virus.

The incubation period for rubella is 12–17 days, but it can last up to 21 days.

Course of the disease

The disease is characterized by a fine red (spotty-nodular) rash on the skin, fever, enlarged lymph nodes in the neck and back of the head, a runny nose and cough, conjunctivitis (inflammation of the conjunctiva), headache, and, rarely, joint pain. A skin rash may not develop in 25–50% of patients.

The disease is more severe in adults than in children; in women, complications may include arthritis (joint inflammation) and/or encephalitis (brain inflammation).

Congenital rubella is characterized by prenatal damage caused by fetal infection. If a pregnant woman contracts rubella, the pregnancy may end in miscarriage or fetal death.

Congenital rubella syndrome is often accompanied by heart and eye malformations. These can also cause microcephaly (brain damage and a small head), mental retardation, deafness, thrombocytopenia (low platelet count), enlargement of the liver and spleen, pneumonia, myocarditis, heart muscle atrophy, and bone damage. Damage caused by congenital rubella may not manifest during infancy but may appear later (e.g., retinal detachment, glaucoma, type 1 diabetes, hearing loss).

What is poliomyelitis?

Poliomyelitis, also known as infantile paralysis, is a viral infectious disease characterized by muscle paralysis.

How is it diagnosed?

Polio is diagnosed by a doctor based on specific symptoms (fever, meningitis, and paralysis), and laboratory tests are also performed.

How does it spread?

The causative agent is the poliovirus, which is highly resistant to extreme conditions, such as freezing. The virus remains infectious both in the low pH environment of the stomach and outside the body (e.g., in water for up to 100 days, in feces for up to 6 months). The virus is destroyed by boiling, UV radiation, and disinfectants.

Infection occurs primarily through contaminated food, water, and surfaces. The virus spreads via the fecal-oral route; in rare cases, also through secretions from the upper respiratory tract. The incubation period is 3–25 days, with an average of 7–11 days.

The risk group consists mainly of children up to 5 years of age, but adults can also become ill.

Course of the disease

The disease can present with varying degrees of severity. It usually begins with a sudden fever (38–40 °C) accompanied by headache, lethargy, malaise, loss of appetite, or vomiting. A runny nose, abdominal pain, diarrhea or constipation, and a drop in blood pressure are also common.

Pain in various parts of the body is typical, especially in the back, spine, and when bending the head or back muscles. Pain often occurs in the very limbs where paralysis later develops. Nearly a quarter of patients with paralysis become disabled, and the disease can also be fatal.

Some patients also develop meningeal symptoms; muscle spasms and tremors in the hands and feet may occur. The pre-paralytic period lasts 2 to 5 days; thereafter, the fever subsides and flaccid paralysis suddenly sets in, which may be accompanied by a new fever spike. Most commonly, the muscles of the legs are affected, and less frequently those of the arms, neck, and trunk.

During the illness, swallowing, breathing, and speech difficulties may occur, as well as pneumonia or encephalitis.

During recovery, headaches, malaise, and other symptoms subside, but flaccid paralysis persists.

What is tick-borne encephalitis?

Tick-borne encephalitis is a viral infectious disease transmitted by ticks. The disease can be severe and affect the central nervous system, causing complications (such as balance and coordination problems, limb paralysis, etc.).

Learn more about tick-borne encephalitis.

How is it diagnosed?

Tick-borne encephalitis is diagnosed based on symptoms of the disease, the presence of a tick bite, and laboratory tests.

How is it transmitted?

Humans become infected through the bite of a tick carrying the virus. Since ticks are the vectors of the virus, the incidence of the disease is influenced by their geographic distribution and seasonal activity from April to October.

Course of the disease

Tick-borne encephalitis is an infectious disease of the central nervous system that often has a two-phase course. In the first phase, the infected person may develop flu-like symptoms 1–2 weeks after exposure: fever accompanied by headache and muscle pain. These symptoms usually last up to a week and then subside.

In about one-third of those infected, the virus may invade the brain and cause meningitis (inflammation of the meninges) or meningoencephalitis (inflammation of the brain and meninges). The disease worsens, leading to high fever, severe headache, neck stiffness, vomiting, drowsiness, and general malaise. Most patients recover, but complications may remain, such as balance and coordination disorders, limb paralysis, headaches, concentration and memory problems, etc. The disease can also be fatal.

What is rotavirus enteritis?

Rotavirus enteritis is a viral intestinal infection.

How is it diagnosed?

Rotavirus enteritis is diagnosed through laboratory tests.

How does it spread?

The disease is more common in winter and spring. Rotavirus spreads easily from person to person through hands, food, or water contaminated with an infected person’s stool, and partly through droplet transmission (e.g., coughing and sneezing). It is the most common intestinal infection in children worldwide, but adults can also become ill. Most children contract it during their first 2–3 years of life, with the highest incidence occurring between 6 and 24 months of age. Rotavirus enteritis occurs both as isolated cases and as outbreaks in groups.

Infection can occur through contact with an infected person’s feces (e.g., contaminated hands), even if the person has not yet shown symptoms; the infectious period lasts 10–21 days from the onset of illness. Objects contaminated with the virus remain infectious for several days. Rotaviruses survive well on surfaces, hands, drinking water, and uncooked food, and are destroyed by chlorine-based disinfectants.

Course of the disease

Symptoms appear 1–3 days after infection and last 4–6 days, rarely longer. The illness begins with fever, abdominal pain, vomiting, and sudden onset of watery diarrhea. In young children, dangerous dehydration can develop rapidly, requiring hospitalization.

Adults may develop the same symptoms, but more often they experience a mild form of the illness with few symptoms.

What is tetanus?

Tetanus, also known as lockjaw, is a bacterial infectious disease characterized by muscle spasms.

How is it diagnosed?

The diagnosis is based on characteristic symptoms. Laboratory tests are performed if necessary.

How does it spread?

Tetanus is caused by a bacterium found in soil, such as in dirt, manure, and dust. The risk of tetanus can arise from scrapes, cuts, and puncture wounds, as well as from objects that penetrate the skin, and from insect and animal bites. Chronic wounds contaminated with the tetanus pathogen can also cause the disease. In developing countries, congenital tetanus also occurs, meaning a newborn contracts tetanus from the mother, and this usually results in death.

Tetanus is not transmitted from person to person, so a sick person is not a danger to others.

Course of the disease

The incubation period for tetanus is 1–21 (on average 7) days.

The disease is characterized by increased muscle tone and spasms. Tetanus usually begins with a spasm of the jaw muscles, followed by difficulty swallowing and stiffness of the neck, shoulder, and back muscles. Later, all voluntary muscles are affected. In milder cases, the disease is treatable; in more severe cases, it is fatal.

Even a very small amount of toxin can cause tetanus. Immunity does not develop after recovering from the disease, which means that revaccination is necessary to prevent future infection.

What is tuberculosis?

Tuberculosis is a highly prevalent and dangerous infectious disease that can take either an acute or chronic course. The disease primarily affects the lungs and lymph nodes, but it can also damage bones, joints, the urinary tract, the reproductive organs, the intestines, and other parts of the body.

How is it diagnosed?

Tuberculosis is diagnosed based on laboratory tests, X-rays, CT scans, and symptoms.

How does it spread?

Tuberculosis bacteria are spread primarily through the air via droplets (from a person with active pulmonary tuberculosis who is coughing) or as airborne dust. In the latter case, the pathogens first settle on surfaces, clothing, or objects, then dry out and become airborne again as the air moves. Rarely, infection can occur through the digestive tract or via damaged skin and mucous membranes.

The tuberculosis pathogen can remain dormant in the body for decades before the disease develops. Those at greatest risk are people in close contact with an infected individual. The body’s overall condition plays a role in the onset of the disease—malnutrition, mental stress, alcoholism, drug addiction, chronic illnesses, and immunodeficiency (including HIV) all contribute to the development of the disease.

The bacteria that cause tuberculosis can remain viable in dried secretions for up to a year in a dark room, but are destroyed by direct sunlight in about 1.5 hours. The bacteria are also quite resistant to disinfectants, while intense ultraviolet radiation destroys them in 2–3 minutes.

Course of the disease

The incubation period is 2–12 weeks. Among the various forms of the disease, pulmonary tuberculosis is the most common, while extrapulmonary forms, such as tuberculosis of the central nervous system, are less frequent.

The symptoms of tuberculosis depend on which organ is affected. The most common symptom of pulmonary tuberculosis is a cough lasting more than 3 weeks, which may be accompanied by sputum production or even coughing up blood, as well as chest pain. Other common symptoms include fever, night sweats, chills, loss of appetite and weight loss, and fatigue. Sometimes tuberculosis can progress without any symptoms.

Tuberculosis is usually a curable disease if it is detected in time and treatment is consistent. The disease is treated with antibiotics, and treatment lasts 6–24 months. If treatment is not consistent, the bacteria causing the disease may develop resistance (failure to respond to medication) to the drugs being used. Multidrug-resistant forms of tuberculosis are very difficult to treat, and the disease can therefore last a very long time. A pathogen that has developed drug resistance can also be transmitted to other people.

What is chickenpox?

Chickenpox is a widespread viral infectious disease characterized by a blistering rash.

How is it diagnosed?

Chickenpox is diagnosed based on the clinical presentation, or symptoms of the disease.

How does it spread?

Chickenpox spreads from person to person through droplet transmission; contact with the fluid from the blisters is also dangerous. Infection occurs through the air when in the same room as an infected person, but the virus can also spread over longer distances, such as through adjacent rooms, hallways, and stairwells. If there is one case of the disease in a family, it is highly likely that other people will also become ill (if they have not yet had the virus). Children up to 10 years of age are most susceptible.

A person is contagious 1–2 days before the appearance of the blistering rash and until the scabs fall off. People with shingles can also be a source of infection, as the varicella-zoster virus is identical to that causing chickenpox. Cases are most common in winter and spring.

The virus lives and replicates only in the human body; outside the body, it survives in saliva droplets for 10–15 minutes and is rapidly destroyed by direct sunlight.

After recovering from chickenpox, lifelong immunity develops.

Course of the disease

The incubation period for chickenpox is 7–21 (on average 14–16) days. The disease begins with respiratory symptoms lasting 1–2 days (e.g., mild runny nose, sore throat) and fever. This is followed by a nodular-vesicular rash.

The rash elements may vary and appear on the body simultaneously. Children generally experience chickenpox with a milder rash; for example, young children may have only a few spots. Adults experience chickenpox much more severely; they may develop over 500 blisters.

The rash usually spreads asymmetrically from the scalp, neck, and face—areas covered by hair—across the entire body. Blisters may also appear on the mucous membranes of the eyes, mouth, and genitals. The chickenpox rash is intensely itchy, causing discomfort and sleep disturbances.

Complications of the disease may include skin or lung inflammation, and in more severe cases, encephalitis, or inflammation of the brain.

What is shingles?

Shingles occurs in people who have been infected with the varicella-zoster virus, which remains dormant in the body and usually reactivates in older adults. The virus causes nerve pain and a skin rash in various parts of the body.

How is it diagnosed?

Shingles is diagnosed through laboratory tests.

How does it spread?

The source of infection for shingles is an infected person. The virus spreads through contact with the blisters or sores of an infected person.

Course of the disease

The patient is contagious for one week after the virus becomes active and the shingles sores appear.

The varicella-zoster virus causes symptoms of chickenpox, which include nerve pain and the appearance of a rash on the body. The rash most commonly appears on the chest and in the area of the ophthalmic branch of the trigeminal nerve. The virus can cause so-called Ramsay Hunt syndrome, characterized by intense abdominal pain, persistent or transient facial nerve paralysis, dizziness lasting for days or weeks, permanent or partially reversible hearing loss, and the presence of a vesicular rash in the external auditory canal, among other symptoms.

People with secondary immunodeficiency (those with malignant tumors, those undergoing immunosuppressive chemotherapy or radiation therapy, and those with HIV infection) are at risk for viral reactivation and the development of Ramsay Hunt syndrome. In many older adults, the nerve pain associated with shingles and indicative of the virus’s presence can last for months or even years. The virus can also spread to the blood vessels of the brain or manifest as a stroke. Symptoms may include headache, fever, mental confusion, and others.

How can you prevent getting sick?

Shingles can be prevented with vaccination. People over 50 are vaccinated regardless of whether they have had an active case of shingles or not. The vaccine can also be administered to people with chronic conditions (such as heart disease and diabetes).

Vaccination recommendation for adults

Who?

People over the age of 50 are vaccinated. It is recommended to discuss the risk of contracting shingles and the appropriate age for vaccination with an infectious disease specialist.

Dosage

• 2 doses of the RZV (Shingrix) vaccine (interval of 2–6 months).

The vaccine is not used to treat acute shingles or similar conditions.

Information on vaccines used in Estonia can be found on the State Agency of Medicines website.

Who should not be vaccinated?

• People with cellular immune deficiency;
• Patients receiving immunosuppressive therapy;
• People who experienced a hypersensitivity reaction after a previous vaccine dose;
• People who have taken medications against herpes virus infection within the previous 48 hours.