Insigth into tropical human infectious diseases: an update

Knowledge on infectious diseases encompasses a vast and constantly changing arena; and consistent research work is imperative to understand and combat the new problems resulting from emerging infectious diseases. Public health workers and epidemiologists aim at lowering morbidity and mortality due to diseases by preventing infections. For the rapidly expanding majority of the world's population; who live in the largely tropical areas of Africa; Asia and Latin America; the greatest threats to health remain tropical infectious diseases. Emerging infectious diseases are new; emerging or drug-resistant infections; whose incidence in humans may increase in the near future. With rapidly increasing international travel; the globalization and industrialization of food supply and exploding populations; infectious diseases pose unprecedented threats around the globe. Thus the imperative need is to promptly recognize; isolate and appropriately manage tropical infectious diseases. This review paper has attempted to provide the much needed insight into the different aspects of the major tropical infectious diseases affecting humans throughout the world

Cross-resistance to Bacillus sphaericus strains in Culex quinquefasciatus resistant to B. sphaericus 1593M.

Bacillus sphaericus 1593M resistant larvae of Culex quinquefasciatus were reared in the laboratory since 1995. Resistance in the larvae was monitored by subjecting selection pressure using B. sphaericus 1593M at every generation. Bioassays were conducted with different strains of B. sphaericus (Bs 2297, Bs 2362 and Bs IAB 59) and confirmed cross-resistance in the present study. The level ranged between 27.3 to 18.2 fold in comparison with susceptible larvae. But Bacillus thuringiensis var israelensis strains (Bti PG14 and Bti 426) did not show any cross-resistance in the larvae and it emphasized a need to study the mode of action of B. sphaericus toxin that induces cross-resistance in the larval strain.