Where is typhoid fever most common. How effective are typhoid vaccines. What are the potential side effects of typhoid vaccination. How can travelers protect themselves from typhoid fever.

Understanding Typhoid Fever and Its Prevalence

Typhoid fever is a bacterial infection that poses a significant health risk in various parts of the world. But where exactly is this disease most prevalent?

Typhoid fever is found globally, but it’s particularly common in areas with poor sanitation and hygiene standards. The high-risk regions include:

• The Indian subcontinent
• Africa
• South and Southeast Asia
• South America

In the United Kingdom, most reported cases of typhoid fever are associated with travel to India, Pakistan, or Bangladesh. This underscores the importance of vaccination for travelers visiting these countries.

Typhoid Vaccination: Types and Effectiveness

Vaccination is a crucial preventive measure against typhoid fever, especially for travelers heading to high-risk areas. What types of typhoid vaccines are available?

In the UK, there are two main types of typhoid vaccines:

1. Vi vaccine: Administered as a single injection
2. Ty21a vaccine: Given as three capsules taken on alternate days

Additionally, for individuals aged 15 and above, there’s a combined typhoid and hepatitis A vaccine available. This combination vaccine provides protection against hepatitis A for one year and against typhoid for three years.

How effective are these vaccines? While they significantly reduce the risk of contracting typhoid fever, it’s important to note that no vaccine is 100% effective. The vaccines work by stimulating the body to produce antibodies that fight against the typhoid bacteria. However, even vaccinated individuals should take precautions with food and water when traveling to high-risk areas.

Vaccination Schedule and Boosters

When should you get vaccinated against typhoid fever? Ideally, the typhoid vaccine should be administered at least one month before travel. However, if necessary, it can be given closer to the departure date. For those who continue to be at risk of typhoid infection, booster vaccinations are recommended every three years.

Side Effects of Typhoid Vaccination

While typhoid vaccines are generally safe, some individuals may experience side effects. What are the common reactions to typhoid vaccination?

The most frequent side effects are mild and localized, including:

• Temporary soreness at the injection site
• Redness
• Swelling
• Hardness around the injection area

Approximately 1 in 100 people may experience a high temperature following vaccination. Less common side effects include:

• Abdominal pain
• Headache
• Nausea
• Diarrhea

It’s important to note that severe reactions to typhoid vaccines are rare. However, as with any medical intervention, it’s crucial to stay under observation for 10-15 minutes after vaccination to monitor for any immediate adverse reactions.

Special Considerations for Typhoid Vaccination

Are there any groups who should exercise caution when considering typhoid vaccination? Indeed, certain individuals may need to take special precautions:

The Ty21a vaccine, which contains a live sample of Salmonella typhi bacteria, is not suitable for people with weakened immune systems. This includes individuals with HIV or those undergoing certain treatments like chemotherapy. Additionally, this vaccine is generally not recommended for children under 5 years old.

For pregnant or breastfeeding women, the safety of Vi and Ty21a vaccines is not fully established. However, vaccination may be considered if there’s a significant risk of typhoid fever exposure.

Children as young as 2 years old can receive the Vi vaccine, making it a more versatile option for families traveling with young children.

Typhoid Prevention for Travelers

While vaccination is a crucial step in typhoid prevention, what other precautions should travelers take when visiting high-risk areas?

Regardless of vaccination status, it’s essential to practice good hygiene and be cautious about food and water consumption. Here are some key tips:

• Only drink bottled water from properly sealed bottles or water that has been recently boiled
• Avoid ice cream and don’t add ice to your drinks
• Steer clear of uncooked fruits and vegetables unless you’ve washed them in safe water or peeled them yourself
• Avoid shellfish, seafood, and salads

These precautions not only help prevent typhoid fever but also protect against other foodborne and waterborne illnesses that travelers may encounter.

Understanding Vaccine Reactions: Beyond Typhoid

While we’ve focused on typhoid vaccination, it’s worth understanding vaccine reactions in a broader context. How common are reactions to vaccines in general?

Vaccines are generally safe and effective, but like any medical intervention, they can cause side effects. Mild reactions can affect up to 15% of people following vaccination. These reactions typically occur within a day or two of immunization and are transient.

Live viral vaccines, such as those for MMR (Measles, Mumps, Rubella), Yellow Fever, and Varicella, may occasionally cause symptoms like fever, headache, tiredness, or rash. These symptoms might not appear until several days after vaccination.

Rare but Severe Reactions

While uncommon, severe adverse reactions to vaccines can occur. These reactions, although potentially serious, usually happen soon after immunization and are generally self-limiting, meaning they resolve on their own without long-term consequences.

Anaphylaxis, for instance, is a severe allergic reaction that can be life-threatening. However, it’s important to note that anaphylaxis is extremely rare and, when it does occur, is quickly and effectively treated without long-term effects. This is why healthcare providers insist on a short observation period after vaccination.

Importance of Vaccination in Travel Health

Why is vaccination such a crucial aspect of travel health, particularly for destinations where typhoid is prevalent?

Vaccination plays a vital role in protecting travelers from potentially serious diseases that they might encounter abroad. For diseases like typhoid fever, which are more common in certain parts of the world, vaccination can significantly reduce the risk of infection.

However, it’s important to remember that vaccination is just one part of a comprehensive travel health strategy. It should be combined with other preventive measures, such as:

• Practicing good hygiene
• Being cautious about food and water consumption
• Using insect repellents in areas where insect-borne diseases are common
• Seeking prompt medical attention if you fall ill during or after travel

By taking a holistic approach to travel health, including appropriate vaccinations and preventive behaviors, travelers can significantly reduce their risk of contracting diseases like typhoid fever and enjoy safer, healthier journeys.

Addressing Vaccine Hesitancy and Misinformation

In the era of widespread information access, vaccine hesitancy has become a growing concern. How can travelers make informed decisions about typhoid vaccination and other travel-related health measures?

It’s crucial to rely on credible sources of information when making decisions about vaccination. Organizations like the Centers for Disease Control and Prevention (CDC), the World Health Organization (WHO), and national health services provide up-to-date, evidence-based information on vaccines and travel health.

If you have concerns about vaccine safety or effectiveness, it’s best to discuss these with a healthcare professional. They can provide personalized advice based on your health status, travel plans, and the latest medical evidence.

Remember, while no medical intervention is without risk, the benefits of vaccination in preventing serious diseases like typhoid fever far outweigh the potential risks for most travelers.

Debunking Common Myths

There are several misconceptions about vaccines that can lead to hesitancy. Let’s address some common myths specifically related to typhoid vaccination:

• Myth: Natural immunity is better than vaccine-induced immunity.
  Reality: While natural immunity from having typhoid fever does occur, the risks associated with contracting the disease far outweigh any benefits of natural immunity. Vaccination provides protection without the dangers of the actual disease.
• Myth: Typhoid vaccines cause typhoid fever.
  Reality: Neither the Vi nor the Ty21a vaccine can cause typhoid fever. The Vi vaccine is made with inactivated components of the bacteria, while the Ty21a vaccine uses a weakened strain that cannot cause the disease.
• Myth: If you’re careful about what you eat and drink, you don’t need the vaccine.
  Reality: While food and water precautions are important, they don’t guarantee protection against typhoid fever. Vaccination provides an additional layer of defense, especially in high-risk areas.

By addressing these myths and providing accurate information, we can help travelers make informed decisions about their health and safety when visiting areas where typhoid fever is prevalent.

Typhoid fever – NHS

Vaccination against typhoid fever is recommended if you’re travelling to parts of the world where the condition is common.

High-risk areas

Typhoid fever is found throughout the world, but you’re more likely to get it in areas where there’s poor sanitation and hygiene. 

High-risk areas include:

• the Indian subcontinent
• Africa
• south and southeast Asia
• South America

Vaccination is strongly recommended if you’re going to be staying or working with local people, or if you’re going to be staying for prolonged periods in areas where sanitation and food hygiene are likely to be poor.

In the UK, most people who get typhoid fever develop it while visiting India, Pakistan or Bangladesh. It’s therefore particularly important that you’re vaccinated if you’re visiting these countries.

Vaccination against typhoid fever is usually free on the NHS from GP surgeries. Private travel clinics also offer the vaccine for about £30.

Typhoid fever vaccines

In the UK, the 2 main vaccines available to prevent typhoid fever are:

• Vi vaccine – given as a single injection
• Ty21a vaccine – given as 3 capsules to take on alternate days

Combined typhoid and hepatitis A injections are also available for people aged 15 or over. Protection against hepatitis A lasts 1 year and protection against typhoid lasts 3 years.

The vaccines work by stimulating your body to create antibodies (infection-fighting proteins) that prevent you getting ill if you become infected with the typhoid bacteria.

But neither typhoid vaccine is 100% effective, so you should always take precautions when eating food and drinking water abroad.

As the Ty21a vaccine contains a live sample of Salmonella typhi bacteria, it isn’t suitable for people with a weakened immune system – for example, people with HIV and those receiving certain types of treatment, such as chemotherapy. 

It also isn’t usually recommended for children under 5, whereas children can have the Vi vaccine from 2 years of age.

It’s unclear whether the Vi and Ty21a vaccines present a risk to pregnant or breastfeeding women. But vaccination should be considered if there’s a significant risk of getting typhoid fever.

The typhoid vaccine should ideally be given at least 1 month before you travel, although if necessary it can be given closer to your travel date.

Booster vaccinations are recommended every 3 years if you continue to be at risk of infection with typhoid bacteria.

Side effects of typhoid fever vaccine

After having the typhoid fever vaccine, some people have temporary soreness, redness, swelling or hardness at the injection site.

About 1 in every 100 people have a high temperature.

Less common side effects include:

• abdominal pain
• headache
• feeling sick
• diarrhoea

Severe reactions are rare for both typhoid vaccines.

Read more about routine NHS vaccinations.

Advice for travellers

Whether you have been vaccinated against typhoid or not, it’s important to take basic precautions when travelling in countries where typhoid fever is present.

For example:

• only drink bottled water from a bottle that was properly sealed, or water that’s been recently boiled
• avoid ice cream and don’t have ice in your drinks
• avoid uncooked fruit and vegetables, unless you have washed them in safe water or peeled them yourself
• avoid shellfish, seafood and salads

Read more about safe and healthy holidays on the ABTA website

Page last reviewed: 20 September 2021
Next review due: 20 September 2024

Vaccination Side Effects | Travel Doctor-TMVC

Reactions to vaccines

Vaccines are both effective and safe, however side effects sometimes occur. These are usually mild reactions and are part of the normal immune response to vaccination. Serious reactions to vaccination such as anaphylaxis are extremely rare.

Common mild vaccine reactions

Mild reactions can affect up to 15% of people following vaccination. These reactions generally occur within a day or two of immunisation and are transient. Live viral vaccines (MMR, Yellow Fever, Varicella) can occasionally cause symptoms such as fever, headache, tiredness and/or rash. These may be delayed until several days after vaccination.

Uncommon, severe adverse reactions

Although they can be severe, most rare vaccine reactions occur soon after immunisation, are self-limiting and do not lead to long-term problems. Anaphylaxis, for example, although potentially life-threatening, is quickly and very effectively treated and has no long-term effects. After vaccination, it is very important to stay for 10-15 minutes of observation.

If you have any concerns about the safety or effectiveness of vaccines, please feel free to discuss this with one of our doctors.

What are the likely side effects?

Modern vaccines are less likely to cause side effects, and there are no restrictions on normal activities – most people can work, drive a car, play sport or go to the gym. Still, it is better to take it easy if you are experiencing any side effects. Modern vaccines do not leave a scar.

Fainting

If you have a history of fainting after injections, make sure you tell the doctor. You may be asked to lie down during vaccination and for a while afterwards so we can be sure you are feeling well before leaving the clinic.

What if I have a cold?

It is medically-safe to be vaccinated if you have a runny nose, sore throat or cough. You should delay vaccination if you have a fever over 39°C or are sick enough to have to stay in bed.

Allergic reactions (Anaphylaxis)

Allergic reactions are rare but may be very serious. After vaccination, notify one of our staff immediately if you feel:

• Warm or itchy, or develop a rash
• Faint (especially on standing up) or dizzy
• Shortness of breath, or start to wheeze or cough
• Your throat, face, hands or limbs begin to swell
• Nausea or stomach pain
• Suddenly tired

Symptoms usually develop within 15 minutes of vaccination, (hence the need to wait in the clinic after vaccination). Occasionally allergic symptoms can occur several days later. If you develop one or more of the above symptoms after leaving the clinic, seek medical help immediately. Persons with severe allergies to eggs may not be able to be immunised against yellow fever, flu, and MMR. Travellers with penicillin allergy however can be vaccinated safely.

Fevers and feeling unwell

Live virus vaccines such as Yellow fever, varicella (chickenpox) and MMR (measles, mumps, and rubella) may cause a fever, headache, tiredness and muscle aches in up to 15% of people, beginning 3-10 days after vaccination. MMR may also cause a transient rash in 5% of people. Most vaccines used today contain killed organisms or fragments of organisms and cannot cause the illness they are used to prevent. A good example is the flu vaccine which cannot cause the flu. However, some people react more strongly to vaccines and may feel unwell afterwards. If you develop a fever or become unwell after vaccination, please call our clinic and speak to one of our doctors or nurses.

Sore or red arm

The most common side effect following vaccination is a sore arm. If you use your arm normally after vaccination, it will help ease the soreness more quickly. In some people, vaccines may cause a lump or hardness at the injection site which persists for a few weeks. If your arm is red, hot and/or sore, place an ice pack over the affected area. You can take paracetamol. Intradermal vaccines (e.g. rabies) may cause itchiness at the injection site and a small surface lump which may persist for a few weeks. This is all part of a normal immune response to vaccination.

Can I drink alcohol after vaccines?

If taking typhoid capsules, alcohol (and food) must not be taken within a few hours of each capsule. However, it is OK to have alcohol after other vaccinations.

There is no evidence that drinking in moderation is harmful after most vaccinations.

In general, there are several reasons to avoid excess alcohol consumption after a vaccination. Excess alcohol consumption can potentially mask the side effects of the vaccine and make it difficult to determine which side effects are attributable to the vaccine or alcohol.

Excessive alcohol consumption on a regular basis may also affect your immune system. Research has shown that alcohol intake of 15 or more drinks per week for men and 8 for women may suppress the immune system along with other factors such as smoking, a lack of sleep and a poor diet.

If you do decide to drink following a vaccine, you should attempt to drink in moderation. If you are concerned about this, you should contact the doctor or nurse administering the vaccine to confirm the safety of alcohol intake following an upcoming vaccine.

Diarrhoea or stomach problems

The oral typhoid vaccine (capsules) may cause mild to moderate nausea, stomach cramps and diarrhoea within 12-24 hours after taking each capsule. If symptoms are more severe after the second capsule, please call our clinic and speak to one of our doctors or nurses.

Will vaccines weaken my immune system?

There is no evidence that vaccination weakens the immune system. In fact, vaccination is a very effective way of strengthening the immune system’s response to diseases. However, to avoid the risk of unnecessary side effects, vaccinations should only be recommended when there is a significant risk of disease.

How do I manage common vaccine side effects?

Many types of vaccines have similar mild side effects which can be managed at home. Common side effects include localised pain, swelling or redness at the injection site, fatigue, muscle or joint pain, weakness, mild fever, or chills.

These side effects indicate that your body is building immunity against the disease. To manage these side effects, over the counter painkillers and fever reducers such as paracetamol or ibuprofen can be taken.

Plenty of rest and hydration are recommended following a vaccine. Most side effects should last no longer than two days. If they last longer, contact your medical provider.

Serious reactions to vaccines occur extremely rarely. If you experience a life-threatening allergic reaction, such as swelling in the face, lips, tongue, throat, difficulties breathing or hives, get immediate emergency medical assistance.

What are the side effects of the flu vaccine?

Like any medical products or medicine, the flu vaccine can cause side effects. Common side effects include redness, warmth or swelling at the site of the injection, headaches, tiredness or body aches. Over the counter pain relievers such as ibuprofen or paracetamol can be used to reduce these symptoms.

Rarely, fainting or dizziness may be experienced. This can be relieved by resting during and after receiving the flu vaccine. A mild fever is also a rare side effect and can also be relieved by taking paracetamol or ibuprofen.

Side effects should not last any longer than two days. Contact the doctor or nurse who is administering the vaccine if you are concerned about post-flu shot side effects.

Importantly, as the flu vaccine is not a live vaccine it cannot give you the ‘flu’.

What are the side effects of the typhoid vaccine?

The typhoid vaccine is used to prevent typhoid fever, a serious potentially life-threatening illness caused by Salmonella Typhi bacteria. The vaccine is widely considered to be both safe and effective at preventing this illness. However, a range of side effects may be experienced following the vaccine.

Two types of typhoid vaccine are available: a live, attenuated (weakened) oral vaccine and an inactivated (killed) vaccine in the form of an injection.

Side effects for the injection typically include swelling, redness or pain at the injection spot, headache, fever and general discomfort. These side effects can be alleviated through rest, over the counter pain medications, and hydration.

Side effects for the oral typhoid vaccine may include mild loosening of the bowel motions, nausea,  and abdominal discomfort or cramping within 12-24 hours after each capsule is ingested. Very rarely people may have moderate diarrhoea or vomiting. Oral typhoid vaccine side effects can be minimised through hydration and rest. If these side effects become severe, contact a medical provider.

Side effects for both typhoid vaccines should not last for more than two days after receiving them. As with any vaccine or medication, there is a very small risk of developing a serious reaction. However, typhoid fever is far more dangerous to your health than the typhoid vaccine. If you have any questions about the typhoid vaccine, or its side effects, contact the medical provider who administered the vaccine to you.

Should I exercise after getting a vaccination?

Generally, it is safe to exercise after vaccinations. However, it may be prudent to avoid very strenuous exercise for a couple of hours after a vaccination. You may experience side effects that could inhibit your usual workout intensity such as local tenderness. If you develop other side effects such as fatigue or body aches in the several days after vaccination, this may also reduce your capacity to exercise. If this does occur, try a lighter exercise than usual, and make sure to listen to your body.

How long do vaccinations last?

The list below outlines the usual duration of protection once the vaccination course is complete. For some vaccines, the duration of protection is uncertain.

• Chickenpox – long-term
• Cholera (oral) – up to 2 years
• Diphtheria – 10 years
• Flu vaccine – up to 1 year
• Hepatitis A – Probable lifetime protection
• Hepatitis B – Lifetime
• Japanese B Encephalitis – 2 years to , depending on the vaccine used
• Measles, Mumps, Rubella – Life time
• Meningitis – new conjugate vaccines give up to 5 years protection

• Pneumonia – >5 years, probably life time
• Polio booster – Life time
• Rabies (pre exposure) – Immune memory persists for life; booster doses needed only
• Tetanus – 5-10 years
• Typhoid (injection) – up to 3 years
• Typhoid capsules x 3 – 3 years
• Typhoid capsules x 4 – 5 years
• Whooping cough – immunity begins to wane after 3-5 years
• Yellow Fever – Long-term; certificate valid for life

Antibodies to Salmonella typhi Vi-antigen

Antibodies to Vi-antigen of the typhoid (S. typhi) pathogen are specific immunoglobulin proteins produced by the immune system in response to infection with the typhoid pathogen and are involved in the body’s immune defense reactions.

Synonyms Russian

Anti-Vi antibodies, the causative agent of typhoid fever.

Synonyms English

Test method

Indirect haemagglutination test (RIHA).

What biomaterial can be used for research?

Venous blood.

How to properly prepare for an examination?

Do not smoke for 30 minutes before the test.

Study background

Typhoid fever is an acute fecal-oral infectious disease caused by Salmonella typhi. The incubation period lasts an average of 9-14 days. The disease begins gradually with general malaise, insomnia and headache, then they are joined by fever, symptoms of damage to the central nervous system in the form of lethargy, impaired consciousness and delirium, as well as stool disorders and a characteristic rash in the abdomen and chest. The source of infection is those suffering from typhoid fever and carriers of S. typhi. Bacteriocarrier can be acute, chronic or transient.

Along with other antigens, the causative agent of typhoid fever contains the Vi-antigen, which ensures the resistance of the pathogen to phagocytosis (the ability of specialized cells of the body, phagocytes, to absorb and digest foreign particles, including microorganisms), contributes to chronic infection and typhoid bacteriocarrier.

What is research used for?

• For the detection of bacteria carriers, including among food workers.
• To evaluate the effectiveness of typhoid vaccination.

When is the test ordered?

• When it is necessary to identify bacteria carriers among employees of food enterprises upon their admission to work.
• If it is necessary to determine the effectiveness of vaccination – 7 days after the introduction of the vaccine.
• When examining persons who have been in contact with patients with typhoid fever or carriers of S. typhi.

What do the results mean?

Reference values: negative.

Detection of antibodies to S. typhi Vi antigen suggests chronic carriage of typhoid bacteria or the development of an immune response to typhoid vaccination. The absence of antibodies indicates that there is no causative agent of typhoid fever, or that the vaccination has been ineffective.

Cause of positive result:

• typhoid bacteriocarrier,
• typhoid vaccination within the last 3 years.

Reasons for negative result:

• lack of immunity to S. typhi due to the fact that there is no infection with the pathogen (if vaccination against typhoid was not carried out),
• lack of immune response or weak immune response to the causative agent of typhoid fever due to disorders in the immune system.

What can influence the result?

• Possible false positive due to cross-reactivity with other Salmonella species, including paratyphoid A, B and C.
• Administration of antibiotic therapy.

Important notes

• Survivors of typhoid fever are relatively resistant to re-infection with S. Typhi, except in cases of massive ingestion of the pathogen.
• Vaccination against typhoid fever is possible for special indications. The protective antibody titer is reached 2-3 weeks after the introduction of the vaccine and persists for 3 years.

Also recommended

• Stool culture for pathogenic flora (disease group and typhoid-paratyphoid group)
• Complete blood count (without leukocyte formula and ESR)
• Leukocyte formula
• Erythrocyte sedimentation rate (ESR)
• Fecal occult blood test
• Urinalysis with microscopy

Who orders the examination?

Infectionist, internist, general practitioner, gastroenterologist.

Vidal test – serological analysis of the causative agent of typhoid fever in the medical laboratory “Optimum” in Sochi (Adler)

Get test results

1. Home
2. Vidal reaction

Serological analysis carried out using the Vidal reaction allows to detect in the human body immune antibodies to the pathogen typhoid fever – bacteria of the genus Salmonella enterica , typhi serotype.

The analysis is carried out as follows: the test serum is diluted, para- and typhoid diagnosticums (standard erythrocytes sensitized by pathogen antigens) are added to the samples, kept at a temperature of +37 degrees for 2 hours. A reaction is considered positive if a precipitate is formed in the form of whitish flakes: with O-agglutination, the precipitate is fine-grained, with H – large plates. With a negative reaction, the liquid in the test tube is cloudy, and there is no precipitate.

execution	up to 10-11 days
Synonyms (rus)	Immune antibodies to the antigen of typhoid-paratyphoid infections
Synonyms (eng)	Widal reaction to O-, H-, Vi- antigen
Methods of analysis	Agglutination test
Preparation for analysis	Exclude alcohol, exercise during the day.
	Last meal – no later than 22:00.
	Do not smoke, have breakfast or drink coffee in the morning.
Biomaterial and collection methods	Venous blood, taken in a manipulation room.

Overview of typhoid fever and its detection

Typhoid fever is a severe systemic infectious process, which is characterized by prolonged fever, general intoxication of the body, damage to the digestive tract and the presence of live bacteria in the blood. The disease is caused by gram-negative intestinal bacteria Salmonella typhi containing antigens:

– somatic – O;
– flagella – H;
– highly immunogenic – Vi.

Source of infection – a sick person or bacterial carrier who excretes pathogenic bacteria with excrement, polluting the soil, water, food, household items. The causative agents of infection penetrate into a healthy body through the small intestine, then through the process of absorption they penetrate into the lymph nodes, liver, bone marrow, spleen, into group lymphatic follicles. Bacteria multiply in the cells of the reticuloendothelial tissue and enter the bloodstream.

In response to the introduction of a pathogen, the human body forms specific and nonspecific cellular immunity . With their help, purification from typhoid bacteria occurs, however, with an immunogenetic deficiency, microorganisms are able to parasitize in the reticuloendothelial system for a long time and form a chronic bacteriocarrier and recurrence of infection.

Clinical diagnosis of infection is difficult, detection of the pathogen by bacteriological method depends on its concentration in the biomaterial. The unconditional confirmation of the presence of typhoid fever are serological screenings, they include the Vidal reaction – an agglutination analysis for the presence of immune antibodies to S. Typhi antigens.

When can a specialist order an examination?

Infectionists, gastroenterologists, therapists prescribe the Vidal test for:

• differential diagnosis of typhoid and paratyphoid infections with gastroenteritis in case of fever, pain in the abdomen, loss of appetite, general malaise, bradycardia;
• dispensary observation of patients who have had the disease;
• detection of bacterial carriers.

Analysis interpretation

Normal – “negative result”, no infection.

With a “positive result” , a titer of 1:100 or more is considered diagnostic, with an atypical form of infection – at least 1:200. The result characterizes an acute or transferred infection, chronic bacterial carriage.

High specificity of the Vidal reaction can be achieved by repeated analyzes in dynamics – at the beginning of the first week of clinical manifestations and after 10 days.