Prevalence of infection, mean worm burden and degree of worn aggregation as determinants of prevalence of disease due to intestinal helminths
Arch. med. res
; 28(1): 121-7, mar. 1997. ilus
Article
em En
| LILACS
| ID: lil-225206
Biblioteca responsável:
MX1.1
RESUMO
Theoretical predictions of disease prevalence due to helminth infections based upon a simple probabilistica model which considers the infection prevalence, the mean worm urden and the degree of worm aggregation are presented. A numerical reappraisal of the likely estimates of the degree of aggregation based upon maximun likelihood estimates of the negative binomial distribution is presented. The prevalence of disease shows a positive relationship with the mean worm burden. This association is hyperbolic when helminth parasites are severely aggregated but is s-shaped when helminth parasites tend to be oversidpersed. The prevalence of disease decreases with the degree of worm aggregation whem the values of the mean intensity are low; as the mean intensity increases this association becomes positive. The relationship between prevalence of disease and prevalence of infection is hyperbolic for severe degrees of parasite aggregation and is s-shaped for intermediate degrees of aggregation. However, if the mean intesnsity is low and the degree of aggreation is high there could be a negative raltionship between the prevalence of disease due to helminth parasites is feasible for determined ranges of values of the infection prevalence, mena intensity and the degree of worm clumping
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Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Helmintíase
/
Helmintos
/
Enteropatias Parasitárias
Tipo de estudo:
Prevalence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
/
Humans
País/Região como assunto:
Mexico
Idioma:
En
Revista:
Arch. med. res
Assunto da revista:
MEDICINA
Ano de publicação:
1997
Tipo de documento:
Article