Quantitative assessment of malaria morbidity based on longitudinal data in 10 Indian villages.

House-to-house visits were made at weekly intervals to investigate malaria morbidity. The survey covered 7337 individuals in 10 villages in Jhansi District, Uttar Pradesh. Incidence rates of 252 spells of sickness from fever and six symptomatic cases of malaria per 1000 population were recorded. The incidence rates of unhealthy periods due to fever, of people sick and of spells of sickness per person were significantly higher in males. Morbidity from fever was highest in the 15-24 year age group in males and in the 10-14 year age group in females. The rates for malaria did not show any correlation with age. Morbidity rates were relatively higher from July to October, peaking in September. The annual slide positivity rate was 2.4%. Plasmodium vivax and P. falciparum were the only species observed in the area, with the former more prevalent.