Clustering of Ascaris lumbricoides and Trichuris trichiura infections within households

Forrester, Janet E.; Scott, Marilyn; Bundy, Donald; Golden, M. H. N.

doi:10.1016/0035-9203(88)90448-8

Cited by 89 publications

(59 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…9 Previous studies have pointed to the importance of shared residence in the distribution of helminthic infections. [10][11][12] The clustering of domestic activities associated with water collection, storage, and usage can lead to the sharing of infective sites and infective water contact behaviors, exposing household members to similar risks of infection. 13 In our previous study, 7 we determined that shared residence accounted for 28% of the variance in fecal egg counts.…”

Section: Introductionmentioning

confidence: 99%

Additive host genetic factors influence fecal egg excretion rates during Schistosoma mansoni infection in a rural area in Brazil.

Bethony¹,

Williams²,

Blangero³

et al. 2002

The American Journal of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

Abstract. This study quantifies the influence of shared household and kinship on egg counts during Schistosoma mansoni infection in a sample from rural Brazil. Detailed genealogic information allowed assignment of 597 individuals to 6 multihousehold pedigrees residing in 145 households. A variance component method was used to partition egg counts into shared household, additive genetic, and individual-specific environmental effects. Host additive genetic effects consistently accounted for a large proportion of the variation in egg counts: 43% in an unadjusted model and 40% in model adjusted for covariates. In a model that examined the confounding of shared household with kinship, additive genetic effects still accounted for 27% of the variation in egg counts and shared household only 12%. The consistently important role for host additive genetic factors on the variation in egg counts points to new ways of modeling and understanding the mechanisms that contribute to trait variation during infection with S. mansoni.

show abstract

Section: Introductionmentioning

confidence: 99%

Additive host genetic factors influence fecal egg excretion rates during Schistosoma mansoni infection in a rural area in Brazil.

Bethony¹,

Williams²,

Blangero³

et al. 2002

The American Journal of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

show abstract

“…The simplicity of these de®nitions conceals the complexity of what a household represents, especially in rural areas where extended families share residences, dwell in compounds, or employ temporarỳ live-in' labourers (Berman et al 1994;Kroeger 1985). Another limitation of previous studies has been the use of a dichotomous dependent variable (`infected' vs.`non-infected'), to reduce the analysis to a test of independence in 2´K 1 contingency tables (Forrester et al 1988;Conway et al 1995). The observed distribution of cases between households is then compared with that expected from a binomial distribution using a 2 v 2 goodness-of-®t procedure.…”

Section: Introductionmentioning

confidence: 99%

Exposure to Schistosoma mansoni infection in a rural area in Brazil. II: Household risk factors

Bethony

Williams

Kloos

et al. 2001

Tropical Med Int Health

View full text Add to dashboard Cite

SummaryA number of studies have pointed out the potential importance of the household in the transmission of schistosomiasis. The clustering of domestic activities associated with water collection, storage, and usage can result in the sharing of transmission sites and infective water contact behaviours. In this study, we employed a variance component method to estimate effects due to individual risk factors and shared residence on the variance in faecal egg counts during Schistosoma mansoni infection. A suite of covariates, which included demographic, socioeconomic, water supply, and water contact behaviour terms, contributed 15% to the variance in faecal egg counts. Shared residence alone accounted for 28% of the variance in faecal egg excretion. When both the suite of covariates and shared residence were considered in the same model, shared residence still contributed 22% to the variance in infection intensity. These results point to the importance of shared residence as a means of capturing the complex interrelationship between shared demographic, socioeconomic, physical environmental, and behavioural factors that in¯uence transmission of schistosomiasis at the household level.keywords Schistosoma mansoni, epidemiology, variance component methods, household, Brazil

show abstract

“…[3][4][5][6] Chronic ascariasis has been implicated in the development and persistence of malnutrition in children, and may have long-term effects on anthropometric indicators of growth. [7][8][9][10] A familial patterning to A. lumbricoides infection has often been noted, [11][12][13] but there have been no detailed genetic epidemiologic analyses of susceptibility to this important helminthic infection.…”

mentioning

confidence: 99%

Genetic analysis of susceptibility to infection with Ascaris lumbricoides.

Williams‐Blangero

Subedi

Upadhayay

et al. 1999

The American Journal of Tropical Medicine and Hygiene

107

View full text Add to dashboard Cite

Abstract. Epidemiologic studies of helminthic infections have shown that susceptibility to these parasites frequently aggregates in families, suggesting the possible involvement of genetic factors. This paper presents a genetic epidemiologic analysis of Ascaris lumbricoides infection in the Jirel population of eastern Nepal. A total of 1,261 individuals belonging to a single pedigree were assessed for intensity of Ascaris infection at two time points. Following an initial assessment in which all individuals were treated with albendazole, a follow-up examination was performed one year later to evaluate reinfection patterns. Three measures of worm burden were analyzed, including eggs per gram of feces, direct worm counts, and worm biomass (weight). For all traits, variance component analysis of the familial data provided unequivocal evidence for a strong genetic component accounting for between 30% and 50% of the variation in worm burden. Shared environmental (i.e., common household) effects account for between 3% and 13% of the total phenotypic variance.

show abstract

Clustering of Ascaris lumbricoides and Trichuris trichiura infections within households

Cited by 89 publications

References 19 publications

Additive host genetic factors influence fecal egg excretion rates during Schistosoma mansoni infection in a rural area in Brazil.

Additive host genetic factors influence fecal egg excretion rates during Schistosoma mansoni infection in a rural area in Brazil.

Exposure to Schistosoma mansoni infection in a rural area in Brazil. II: Household risk factors

Genetic analysis of susceptibility to infection with Ascaris lumbricoides.

Contact Info

Product

Resources

About