Flying and Health — Page 112, Lesson 174

I want to walk you through a section on infectious diseases that every professional pilot needs to understand. When you're flying internationally, you're exposed to diseases that most people never encounter, and your medical fitness is a regulatory requirement. Let's start with cholera. Cholera is contracted through food or water that has been contaminated by the faeces of infected persons. Outbreaks of cholera reflect poor sanitary and hygiene conditions. The symptoms include vomiting, cramps, and diarrhoea, which result in a dangerous loss of body fluids. In fact, liquid loss may be as much as 19 litres a day. That's an enormous volume — your body cannot sustain that without rapid medical intervention. Once fluids have been replaced, antibiotics may be given to stop the bacteria. A vaccine is available, but it is of questionable benefit, so you cannot rely on it. The best preventative measures are drinking only boiled or bottled water and eating only cooked food. Here's a practical point that's especially important for aircrew: you should always check that the seal is intact before drinking from a bottle of water at hotels or restaurants. In many developing countries, bottles are refilled and thus may contain contaminated water. Next, yellow fever. Yellow fever is an acute destructive disease usually found in tropical regions. It is caused by a virus transmitted by infected mosquitos. The virus has an incubation period of 3 to 8 days — that's the time between being bitten and showing symptoms. Symptoms include fever, liver damage with accompanying jaundice, and intestinal disorders. Jaundice is a yellowing of the skin and eyes caused by liver damage. Treatment consists of maintaining the blood volume, and transfusions may be necessary. Vaccination confers immunity for 10 years, so you need to keep that up to date if you're flying into endemic areas. Now tetanus. Tetanus is an infection transmitted through spores via a puncture of the skin, and it attacks the central nervous system. The most characteristic symptom of tetanus is lockjaw — that's a spasm of the jaw muscles that makes it impossible to open your mouth. After the initial vaccination, which is 3 doses over a 12-month period, revaccination every ten years is necessary. Typhoid fever is contacted through infected milk, water, or food, and it affects the large intestine. Symptoms include high fever, headache, constipation which soon changes to diarrhoea, and a rash which usually appears on the chest and abdomen. The disease is serious and can be fatal. The vaccine does not provide complete protection, and a booster is required after two years. Finally, hepatitis. Hepatitis is a virus that affects the liver, causing its enlargement, and can sometimes result in liver failure. Symptoms include fever, chills, headache, decreased appetite, tenderness in the upper right abdomen, dark urine, light-coloured faeces, and yellow skin or eyes — that's jaundice again. Left untreated, the victim can fall into a coma and die. Of the six forms of hepatitis, the three most common are discussed briefly. Let's look at each. Hepatitis A is primarily spread through food and water contamination. Undercooked or raw shellfish and seafood, along with raw vegetables, are likely sources. Symptoms develop about one month after exposure to the virus. It has also been reported that Hepatitis A can be transmitted through sexual contact and drug use via needle exchange. Gamma globulin is used as a vaccine, but it can be of limited protection and short-lived. Hepatitis B is more serious than Hepatitis A, resulting in chronic liver disease. It is spread through blood transfer rather than by eating. It is transmitted primarily via intravenous drug use. That's where the excerpt ends for now, but you can see the pattern — each disease has a specific transmission route, incubation period, symptoms, and prevention strategy that you need to know for your own health and your medical certification.