Chapter 8 : The Urban Neglected Tropical Diseases: Leptospirosis, Dengue, and Rabies

Abstract:

The neglected tropical diseases (NTDs) leptospirosis, dengue, and rabies have particular importance as urban health problems in developing countries. Leptospirosis is one of the world’s most common zoonoses, transmitted through contact with bodies of water, such as canals and sewers, contaminated with leptospires. In urban areas, contamination occurs through exposure to the urine of rats and stray dogs, which teems with leptospires. Adequate prevention requires having an intact system of surveillance and case detection as well as environmental control. Dengue fever is one of the most common NTDs of urban areas, and the number of dengue cases is expected to rise as a consequence of increasing urbanization and global warming. Dengue is caused by a single-stranded RNA flavivirus and transmitted by the bite of a female Aedes mosquito. A. aegypti is the most common insect vector species. The most feared complication of dengue is dengue hemorrhagic fever (DHF), which is associated with severe morbidity. No vaccine is yet available for dengue, and public health control relies on labor-intensive practices of environmental vector control. Approximately 50,000 people die from rabies annually. Most of these deaths occur as the result of stray-dog bites in developing countries. There is also an enormous economic toll from rabies. This is because of the need to administer postexposure prophylaxis (PEP) with rabies vaccine to almost anyone bitten by a dog in developing countries. The public health control of rabies in many countries has been achieved through aggressive campaigns to vaccinate dogs in urban centers.