Tropical Diseases

A hopeful new development in tropical medicine is the vaccine for malaria, which was in field trials in the middle 1990s. The vaccine, developed by Colombian Manuel Patarroyo, is made up of three peptides synthesized chemically and connected using a fourth peptide from the malaria parasite.

The vaccine is designed to protect against falciparum, the most deadly strain of malaria. Results of clinical tests in Colombia, Ecuador, Venezuela, and Tanzania reported in 1994 show some success against the disease. The Tanzania trial of about 600 children reduced the incidence of malaria by 31%. This shows that the vaccine has some promise. Experts note that while the vaccine did not provide 100% protection, it still would be valuable to cut sickness and death from malaria by 31%. The next step is to see if the vaccine can be improved and to conduct larger field trials.

Other experimental vaccines are also being tested. A therapeutic vaccine for tuberculosis is currently being tested which reduces the time it takes to treat the disease, which currently is about six months. Shortening the treatment time would improve the odds that treatment is completed by the patient.

Another vaccine which could reduce the sickness linked to tropical diseases is a new vaccine for leishmaniasis. The vaccine, which is in clinical trials, has fewer side affects and costs about one-tenth less than drugs currently used to treat the disease. However, because the drug is not in production for distribution yet, the ultimate cost of the medicine is not clear.

Other strategies are also essential to stem the tremendous cost in illness and death from tropical diseases. While World Health Organization efforts have boosted the rate of immunization for many diseases, there are still millions of children who do not receive adequate immunization for common early childhood diseases such as measles and whooping cough. Efforts to provide such proven preventive measures to more children will yield great benefits in health and longer life.

Efforts to boost access to health providers and educational information also stand to benefit residents of tropical disease areas. Knowing how to care for children with diarrhea, adults with hookworm, or many other diseases could make a vast difference. Finally, the prevalence of diseases linked to dirty water and dirty soil drive home the importance of better sewage systems and basic public health measures which western countries generally adopted years ago. Diseases carried by insects are tackled through insecticides, clearing brush and standing water where the carriers may proliferate; sexually transmitted diseases are addressed by educating communities about safer sex practices, and providing condoms; immunization programs may cut down on some diseases; efforts to create vaccines for other diseases are underway; donor blood is undergoing increasingly more stringent screening to avoid transmitting disease through this route.