Diseases transmitted by Water and Food
In situations where travellers’ diarrhoea is common so to is Hepatitis A. This is a viral disease of the liver & is the most common vaccine preventable disease that travellers to less developed areas of the world contract.
This virus is transmitted through contaminated food & water. For those eating & drinking in areas where environmental sanitation & personal hygiene are poor the risk may be as high as 1 in 50 per month of travel. Even "5 star" travel is not without risk. Those infected with the virus can be incapacitated for an average of two months & it may be more than 6 months before normal daily activities can be resumed. Of great importance is that there is no treatment to shorten the duration of illness. This is a severe disease in those over the age of 40 with some studies showing a mortality rate of up to 3% from liver failure
In the last 40 years water quality & waste disposal has been excellent in countries like Australia & New Zealand hence very few individuals under the age of 55 will have developed natural immunity through exposure to the virus in the environment. It is therefore very important that travellers receive protection against this disease. The newer vaccines (HAVRIX & VAQTA) offer excellent long-term protection with minimal side effects.
For travelers who require protection against Hepatitis A & Hepatitis B there is a combined vaccine,(TWINRIX), available. This vaccine involves 3 doses over 6 months. Your doctor will discuss the suitability of this option for your circumstances.
In areas of the world where poor environmental sanitation exists, food & water can be contaminated by germs of human excreta, including salmonella typhi the cause of typhoid fever. It is usually transmitted by dirty fingers on to food, such as an individual not washing his/her hands after using the lavatory.
Typhoid fever causes fever, headache, rash & occasionally diarrhoea & is endemic in the developing world. It can cause serious illness & even death if not treated.
Vaccination against typhoid is strongly recommended for travellers over 2 years age to areas of poor sanitation. Backpackers are most at risk of the disease.
Newer vaccines with fewer side effects are now available. The injectable TYPHIM Vi & TYPHERIX as a single dose vaccine & the oral live vaccine TYPHVAX (3 or 4 capsules) have considerably fewer side effects, while providing good levels of protection.
This is an acute infection caused by a virus which attacks the nervous system & can lead to paralysis. Transmission is by faecal contamination of food, usually by unhygienic food handlers or flies, or directly from infected nasal secretions. Polio is a serious disease with a vaccine that is very safe & effective. Although most Australians & New Zealanders will have been immunized in childhood it is important that travellers be aware that the efficacy wanes after ten years & a booster dose is advisable prior to travel especially if visiting a country where the disease is still found.
The poliovirus has almost been stamped out in the western pacific & is on track for eradication worldwide within two years, despite thousands of cases reported last year in India & Pakistan.