Protecting Yourself Before You Return Home
-- By Dr. Charlie Easmon
After "x" years studying or working in the USA or Western Europe, you are due to return home. Home is a place, which if you were a traveller, you would be advised to have a range of vaccinations. The key issue for you is about risk assessment. Are you already immune to the diseases that have a higher incidence in your country than in the US or Western Europe? This web piece will give a brief overview of the vaccine preventable infectious diseases, as well as those for which the risk can be reduced by repellents or insecticides, and finally malaria chemoprophylaxis, or emergency treatment.
There will also a brief mention of sexually transmitted infections (STI).
What is your personal risk of acquiring a vaccine preventable disease on your return home, after an extended stay in a place where that disease doesn't exist? Is it higher or lower than that of a tourist? We all know that the prevalence of an infectious disease in a population is not evenly spread. Those earning less, and living in greater poverty have the highest incidences of exposure. If you came from relatively privileged background, it cannot be assumed that you were exposed to Hepatitis A or Hepatitis B despite a high overall prevalence in your home country.
If we look at the specific vaccine preventable risks: Both hepatitis A and Typhoid are transmitted from muck to mouth. An outbreak can occur following only one lapse in the food chain, as shown by the recent infections in Philadelphia, which affected more than ninety people. In the early 1900's, Typhoid Mary infected several eminent families in New York State. It would make sense to be covered for these two vaccinations.
Polio is about to be eradicated with the help of the World Health Organisation (WHO) and Rotary International (RI). However, until it is fully eradicated it would make sense to have a regular ten-year booster, after a primary course.
The same principle, can apply to Tetanus and Diptheria. However, it is thought that five doses of Tetanus are likely to be sufficient in most people's lifetime.
Those of you returning to parts of Africa and South America should think about yellow fever vaccine. No recent cases in your home area is no guarantee of protection. The virus may be in the monkey population, and if you are not immune, you may be the first indicator that this potentially fatal disease can easily be transmitted to humans. Those of you returning to rabies endemic countries like India, should think about rabies vaccination. In India, there are still 30,000 deaths of humans from rabies each year. The fact that you graduated from Massachusetts Institute of Technology (MIT) makes you no less attractive to a rabid animal!
Malaria Prophylaxis is Controversial
Malaria prophylaxis is one of the most controversial issues of all. In a malaria endemic area, it is clear that no one has one hundred percent immunity, and that whatever partial immunity people may develop wanes after lack of exposure to infection. How quickly and how much it wanes is not known, but some experts at the Hospital of Tropical Diseases (London) believe that after six months away from an endemic area you should not regard yourself as having any immunity to malaria. What this means is that you now have the same risk of malaria as a traveler. In fact you have greater risk as a product of the time that you will spend at home. The risk assessment then is a balance of no chemoprophylaxis versus chemoprophylaxis with its associated financial costs, and the theoretical but not proven possibility of long term side effects.
Is it better to get the odd attack of Malaria and possibly re-develop a degree semi-immunity? There is no definitive answer, but we have to accept that malaria can kill. Whatever you decide to do, have a low diagnostic threshold. Seek early effective treatment and always consider the possibility of malaria after you return home. Mosquito repellents, insecticides and insecticide-treated-bed nets, can help protect you and your family against diseases such as malaria as well as Dengue Fever.
Finally, keep in mind that whatever sexual health precautions you have been taking in the USA or Western Europe, need to be maintained or increased in parts of the world where HIV, Hepatitis B, Hepatitis C, and Sexually Transmitted Infections are more common.