Hepatitis A is the most common, and the virus is spread mainly by poor sanitation or kitchen hygiene, particularly in developing countries. The virus can even be picked up by eating shellfish caught from waters contaminated with sewage. The illness is usually severe enough to incapacitate an adult for some time, although this may happen after returning from holiday, as the incubation period is often a matter of weeks. The symptoms are fever, nausea and muscle aches, progressing to jaundice, which causes severe fatigue and nausea. There is also a risk from unregulated acupuncture and tattooing.
Immunisation is available against both forms of the disease.
Typhoid Typhoid, or enteric fever, is caused by one of two bacteria, Salmonella typhi and Salmonella paratyphi. It is caught from food or water tainted with faeces from infected people, and is more common in countries such as India, Pakistan and Nepal. Symptoms include prolonged fever, headache, loss of appetite, nausea, and fatigue. Untreated, the illness can last for three to four weeks and is fatal in about ten percent of cases. Treatment is with antibiotics, although there are various typhoid vaccines on the market.