Hepatitis A is a viral infection transmitted through contaminated food and water or by direct contact with an infectious person. Symptoms are often mild or absent in young children, but the disease becomes more serious with advancing age. Recovery can vary from weeks to months. Following hepatitis A illness, immunity is lifelong.

Those at increased risk include travellers visiting friends and relatives, long stay travellers, and those visiting areas of poor sanitation.

Prevention

All travellers should take care with personal, food and water hygiene.

Hepatitis A vaccination

As hepatitis A vaccine is well tolerated and affords long-lasting protection, it is recommended for all previously unvaccinated travellers.

Hepatitis A in brief

Tetanus is caused by a toxin released from Clostridium tetani and occurs worldwide.  Tetanus bacteria are present in soil and manure and may be introduced through open wounds such as a puncture wound, burn or scratch.

Prevention

Travellers should thoroughly clean all wounds and seek appropriate medical attention.

Tetanus vaccination

• Travellers should have completed a primary vaccination course according to the UK schedule.
• If travelling to a country where medical facilities may be limited, a booster dose of a tetanus-containing vaccine is recommended if the last dose was more than ten years ago even if five doses of vaccine have been given previously.

Country specific information on medical facilities may be found in the ‘health’ section of the FCO foreign travel advice website.

Tetanus in brief

Typhoid is a bacterial infection transmitted through contaminated food and water. Previous typhoid illness may only partially protect against re-infection.

Those at increased risk include travellers visiting friends and relatives, those in contact with an infected person, young children, long-term travellers, and those visiting areas of poor sanitation.

Prevention

All travellers should take care with personal, food and water hygiene.

Typhoid vaccination

• Both oral and injectable typhoid vaccinations are available and are recommended for those at increased risk
• Vaccination could be considered for other travellers

Typhoid in brief

Cholera is a bacterial infection transmitted by contaminated food and water. Cholera can cause severe watery diarrhoea although mild infections are common. Most travellers are at low risk.

Prevention

All travellers should take care with personal, food and water hygiene.

Cholera vaccination

This oral vaccine is recommended for those whose activities or medical history put them at increased risk.  This includes:

• aid workers
• those going to areas of cholera outbreaks who have limited access to safe water and medical care.
• those for whom vaccination is considered potentially beneficial.

 Cholera in brief

Hepatitis B is a viral infection; it is transmitted by exposure to infected blood or body fluids. This mostly occurs during sexual contact or as a result of blood-to-blood contact (for example from contaminated equipment during medical and dental procedures, tattooing or body piercing procedures, and sharing of intravenous needles). Mothers with the virus can also transmit the infection to their baby during childbirth.

Hepatitis B in Vietnam

2% or more of the population are known or thought to be persistently infected with the hepatitis B virus (intermediate/high prevalence).

Prevention

Travellers should avoid contact with blood or body fluids. This includes:

• avoiding unprotected sexual intercourse.
• avoiding tattooing, piercing, public shaving,  and acupuncture (unless sterile equipment is used)
• not sharing needles or other injection equipment.
• following universal precautions if working in a medical/dental/high risk setting.

A sterile medical equipment kit may be helpful when travelling to resource poor areas.

Hepatitis B vaccination

Vaccination could be considered for all travellers, and is recommended for those whose activities or medical history put them at increased risk including:

• those who may have unprotected sex.
• those who may be exposed to contaminated needles through injecting drug use.
• those who may be exposed to blood or body fluids through their work (e.g. health workers).
• those who may be exposed to contaminated needles as a result of having medical or dental care e.g. those with pre-existing medical conditions and those travelling for medical care abroad including those intending to receive renal dialysis overseas.
• long-stay travellers
• those who are participating in contact sports.
• families adopting children from this country.

Hepatitis B in brief

JE is a viral infection transmitted to humans from animals (mainly pigs and birds) by mosquitoes which typically breed in rice paddy fields, swamps and marshes, and predominantly feed between dusk and dawn.

Those at increased risk include travellers who are staying for a month or longer during the transmission season, especially if travel will include rural areas with rice fields and marshland.

Travellers on shorter trips (typically less than a month), or trips that take place outside the peak transmission season and those who restrict their visits to urban areas are usually considered to be at very low risk.

Japanese encephalitis in Vietnam

JE occurs in this country. The transmission season is typically from May to October.  Rarely cases in travellers are reported outside these months.  The highest rates of JE have been reported in and near Hanoi.

Prevention

All travellers should avoid mosquito bites particularly between dusk and dawn.

Japanese encephalitis vaccination

• Vaccination is recommended for those whose activities put them at increased risk (see above).
• Vaccination could be considered for those on shorter trips if the risk is considered to be sufficient e.g. those spending time in areas where the mosquito breeds such as rice fields or marshlands, or pig farming areas.

Japanese encephalitis in brief

Rabies is a viral infection which is usually transmitted following contact with the saliva of an infected animal most often via a bite, scratch or lick to an open wound or mucous membrane (such as on the eye, nose or mouth). Although many different animals can transmit the virus, most cases follow a bite or scratch from an infected dog. In some parts of the world, bats are an important source of infection.

Rabies symptoms can take some time to develop, but when they do, the condition is almost always fatal.

The risk of exposure is increased by certain activities and length of stay (see below). Children are at increased risk as they are less likely to avoid contact with animals and to report a bite, scratch or lick.

Rabies in Vietnam

Rabies has been reported in domestic and wild animals in this country. Bats may also carry rabies-like viruses.

Prevention

• Travellers should avoid contact with all animals. Rabies is preventable with prompt post-exposure treatment.
• Following a possible exposure, wounds should be thoroughly cleansed and an urgent local medical assessment sought, even if the wound appears trivial.
• Post-exposure treatment and advice should be in accordance with national guidelines.

Rabies vaccination

Pre-exposure vaccinations are recommended for travellers whose activities put them at increased risk including:

• those at risk due to their work (e.g. laboratory staff working with the virus, those working with animals or health workers who may be caring for infected patients).
• those travelling to areas where access to post-exposure treatment and medical care is limited.
• those planning higher risk activities such as running or cycling.
• long-stay travellers (more than one month).

A full course of pre-exposure vaccines simplifies and shortens the course of post-exposure treatment and removes the need for rabies immunoglobulin which is in short supply world-wide.

Rabies in brief

TB is a bacterial infection transmitted most commonly by inhaling respiratory droplets from an infectious person. This is usually following prolonged or frequent close contact.

Tuberculosis in Vietnam

The average annual incidence of TB is greater than or equal to 40 cases per 100,000 population (further details).

Prevention

Travellers should avoid close contact with individuals known to have infectious pulmonary (lung) TB.

Those at risk during their work (such as healthcare workers) should take appropriate infection control precautions.

Tuberculosis (BCG) vaccination

According to current national guidance, BCG vaccine should be recommended for those at increased risk of developing severe disease and/or of exposure to TB infection e.g. when the average annual incidence of TB is greater than or equal to 40 cases per 100,000 population. See Public Health England’s Immunisation against infectious disease, the ‘Green Book’.

For travellers, BCG vaccine is also recommended for:

• unvaccinated, children under 16 years of age, who are going to live for more than 3 months in this country. A tuberculin skin test is required prior to vaccination for all children from 6 years of age and may be recommended for some younger children.
  
  
• unvaccinated, tuberculin skin test negative individuals under 35 years of age at risk due to their work such as healthcare workers, prison staff and vets. Healthcare workers may be vaccinated over the age of 35 years following a careful risk assessment.
  
  

There are specific contraindications associated with the BCG vaccine and health professionals must be trained to administer this vaccine intradermally (just under the top layer of skin).

Following administration, no further vaccines should be administered in the same limb for 3 months.

The BCG vaccine is given once only, booster doses are not recommended.

Tuberculosis in brief

Atovaquone 250mg/Proguanil 100mg combination preparation:

• start one to two days before arrival in the malaria risk area
• for adults, one tablet is taken every day, ideally at the same time of day for the duration of the time in a malaria risk area and daily for seven days after leaving the malaria risk area
• take with a fatty meal if possible
• for children paediatric tablets are available and the dose is based on body weight (see table below)

Doxycycline 100mg:

• start one to two days before arrival in the malaria risk area
• adults and children over 12 years of age take 100mg daily, ideally at the same time of day for the duration of the time in a malaria risk area and daily for four weeks after leaving the malaria risk area
• take with food if possible; avoid taking this drug just before lying down
• not suitable for children under 12 years of age