Epidemiological, clinical and therapeutic features of Bihar kala-azar (including post kala-azar dermal leishmaniasis).

This epidemic of kala-azar in Bihar, India, started from a small block and gradually spread to almost all of North Bihar. Vaishali was the district most affected, with the highest incidence rate of 5.9 per thousand in 1978. The epidemic spread more to the east than to the west. In 1977 there were 100,000 cases of kala-azar in Bihar and in Vaishali district the death rate was 28.7% of affected cases. It took five years to control the epidemic. 750 parasitologically confirmed cases of kala-azar were studied. The male:female ratio was 5.5:1. 63.4% of cases were aged 10 to 29 years. Clinical features were classical. Sodium stibogluconate, used as a first line drug, was effective in 92.6% of cases. By increasing the course of antimonial therapy from 10 to 20 days the relapse rate was reduced to 0.5% compared with 15% in the previous epidemic. Kala-azar patients who also had tuberculosis were treated with the antimonial and antituberculosis drugs concurrently and all cases recovered. 86 cases unresponsive to sodium stibogluconate were given pentamidine, which was effective in 93.4%. Side effects with sodium stibogluconate were minimal, but were common and serious with pentamidine. The need for a safer drug effective in cases which do not respond to antimony was very evident. 20 cases of post kala-azar dermal leishmaniasis (PKDL) were reviewed: two had no previous previous history of kala-azar. The relapse rate was higher in PKDL than in kala-azar.