The distribution of Ascaris lumbricoides in human hosts: a study of 1765 people in Bangladesh

Citation
A. Hall et al., The distribution of Ascaris lumbricoides in human hosts: a study of 1765 people in Bangladesh, T RS TROP M, 93(5), 1999, pp. 503-510
Citations number
19
Categorie Soggetti
Medical Research General Topics
Journal title
TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE
ISSN journal
00359203 → ACNP
Volume
93
Issue
5
Year of publication
1999
Pages
503 - 510
Database
ISI
SICI code
0035-9203(199909/10)93:5<503:TDOALI>2.0.ZU;2-S
Abstract
The Ascaris lumbricoides expelled by 1765 people in a poor urban community in Bangladesh were recovered and counted after the subjects had been treate d with pyrantel pamoate. The subjects were divided into 22 classes by age a nd sex (mean n = 80) to examine how prevalence, mean worm burdens and measu res of aggregation of worms varied with age and between the sexes, and to s ee how a measure of aggregation, k, calculated in 3 ways (by maximum likeli hood, from moments, or from the percentage uninfected) compared with an emp irical aggregation index (the percentage of subjects who expelled an arbitr ary 80% of all worms) and with the proportion who were moderately to heavil y infected (defined as greater than or equal to 15 worms). The prevalence o f infection ranged from 64% to 95%, mean worm burdens ranged from 7 to 23 w orms, and k ranged from 0.3 to 1.2. There were significant differences betw een adult males and females in the prevalence of infection, mean worm burde ns and measures of aggregation, differences which are probably driven more by behaviour than immunity. The parameter k was better described in terms o f the proportion who were moderately to heavily infected (linear; range 0.1 5-0.58) than by the empirical aggregation index (non-linear; range 0.30-0.4 9).