Hookworm infection in a rural community in south India and its association with haemoglobin levels.

Faecal samples were obtained from 1113 persons living in a rural area in South India, and the hookworm ova load (Necator americanus) was determined using Kato's thick smear method. Evidence of hookworm infection was present in 92%, 77% having a count of under 100 epg, 11% a count of 1000 to 1999 epg, and 4% having counts between 2000 and 12,000 epg. Females had significantly higher ova counts than males on the average, but age did not appear to have any effect. Haemoglobin was also estimated: 80% of adult males, 87% of adult females and 90% of children were anaemic. There was a significant negative association between ova load and haemoglobin level, and the decrease in haemoglobin for a doubling of the ova load was estimated by regression analysis to be 0.18, 0.29 and 0.16 g/dl in adult males, adult females and children, respectively. There was nearly perfect agreement in the ranking of 10 clusters by mean ova count and mean haemoglobin level or percentage with anaemia.