Bugs – HEPATITIS A
With an increase in foreign travel tourists are continually exposed to diseases which are rare within their own borders. Some diseases are merely annoying and may cause mild irritation, while others are significantly more serious and may even lead to death. Hepatitis A fits between these two extremes. Although it can certainly kill, most patients survive after experiencing a miserable few months.
Hepatitis A has been known as ‘Infectious Jaundice’ since 1912 due to its nature of easy transmission within households or through closely knit communities. Today, it is most commonly known as ‘Yellow Jaundice’ which signifies that in some cases the yellow discolouration may be very severe. Yellow Jaundice should not be confused with Yellow Fever.
Mode of Infection
Hepatitis A (HAV) is caused by a small unenveloped symmetrical RNA virus which measures approximately 27nm. Due to its very small size the virus can easily transfer through normal water filtration systems. Where after it invades into liver cells and is excreted in bile and faeces.
Following an incubation period, which usually spans 25 to 30 days, the individual presents with diffuse ‘flu-like’ symptoms. Because there are seldom localising signs or symptoms, patients are often misdiagnosed until their skin starts to discolour and becomes distinctly yellow. The disease may however be correctly diagnosed during the pre jaundice phase based on a significant history of exposure and symptoms such as some tenderness in right upper quadrant of the abdomen and a history dark looking urine. Other typical signs and symptoms include anorexia, fatigue, vomiting, abdominal discomfort, fever, muscle aches and, occasionally, arthritis has been reported. In children, especially under 5 years of age, the disease may present with an non-jaundiced pattern. That is the jaundice may be absent or very mild. These children may just become anorexic for a week or so and somewhat lethargic.
The majority of adults remain lethargic and off work for one to two months and feel under par for up to six months. (Many complain bitterly about having to stay off alcohol for up to 18 months – ‘worse than the disease itself!’).
In children the disease is usually mild and often, in those under 5, they remain asymptomatic. However a proportion of these children can go on to develop significant disease and may require liver transplantation.
The disease occurs throughout the world and its outbreaks well reported. With the improvements in personal and public hygiene the disease now only tends to occur in small epidemics in first world countries. However, in the developing parts of our world, where faecal contamination of food and water supplies are a common occurrence, many of the population will be exposed to the disease while they are children. In these regions the disease remains endemic and tourists will be at significant risk.
The disease is mainly transmitted through the oro-faecal route (contaminated fingers, food and water consumption) but sexual transmission is also well reported. The virus is only present in the blood for a very brief time so transmission through blood transfusion or needle stick exposure is very rare. The virus may be present for a transient time in saliva and so could, in theory, be coughed from person to person. This would be rare and by far the most common means of transmission is through the drinking of contaminated water or the consumption of contaminated foods.
Without much doubt undercooked bivalve shellfish constitute the greatest single hazard for travellers to many of the tropical regions of the world. If the local population excretes the virus in their faecal material – and this is disposed of into the sea close to shell fish beds – then there is a distinct probability that these shell fish will filter the water and concentrate this contaminated faecal material. Bivalve shell fish are generally undercooked (steamed for 45 seconds etc.) and thus full sterilisation cannot occur.
There is no well recognised treatment for this viral disease and the majority of patients will recover with supportive therapy. In patients with fulminant disease liver transplantation will need to be considered. Post treatment recommendations
Special care should be taken with food and water hygiene as this is paramount in protecting the individual traveller. Vaccination should serve as second line defence.
Before administering vaccinations, it should be considered that a vast majority of previously disadvantaged South Africans are Hepatitis A positive and as such have a natural immunity to the disease. It might thus be prudent to do a blood test to determine Hepatitis status prior immunisation.
Most South African Travel Medical practitioners should have access to more than one vaccine, with the best option decided on in consultation.
Generally one single vaccine provides protection within 2 to 4 weeks which last for approximately 6 months to 1 year. With a single booster dose (at that time) maintaining the protection for at least a further 10 years.