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

Bethony, Jeffrey M.; Williams, Jeff T.; Blangero, John; Kloos, Helmut; Gazzinelli, Andréa; Soares‐Filho, Britaldo; Coelho, Leonardo Gomes Martins; Fraga, Lúcia Alves de Oliveira; Williams‐Blangero, Sarah; LoVerde, Philip T.; Corrêa-Oliveira, Rodrigo

doi:10.4269/ajtmh.2002.67.336

Cited by 46 publications

(33 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is not yet clear whether this observed pattern is the result of changes in behavior or acquired immunity as the endemic population ages. 1,2 Recently, both Webster and coworkers 3 and our group 4,5 have reported that another rise in infection intensity occurs among the elderly, suggesting a loss of this partially acquired immunity by aged people. To date, there has been no systematic study of the immune response of individuals residing in S. mansoni endemic areas over the age of 60 years.…”

Section: Introductionmentioning

confidence: 93%

Production of interferon-γ by natural killer cells and aging in chronic human schistosomiasis

Speziali

Bethony

Martins‐Filho

et al. 2004

Mediators of Inflammation

View full text Add to dashboard Cite

BACKGROUND : Aging is associated with several alterations in the phenotype, repertoire and activation status of lymphocytes as well as in the cytokine profile produced by these cells. As a lifelong condition, chronic parasitic diseases such as human schistosomiasis overlaps with the aging process and no systematic study has yet addressed the changes in immune response during infection with Schistosoma mansoni in older individuals. Aim : Herein we study the influence of immunological alterations brought about by senescence in the course of schistosomiasis.Materials and methods : Individuals 10 Á /95 years of age, from both sexes, from an endemic area for S. mansoni infection were matched by intensity of infection as measured by egg counts. We analyzed, as a parameter, cytokine expression by lymphocytes and natural killer cells after in vitro stimulation with soluble egg antigen and soluble worm antigen using flow cytometry. Results : We demonstrated that the frequency of CD16 interferon-g (IFN-g) natural killer cells in negative individuals over the age of 70 years is significantly higher than in positive individuals after in vitro stimulation with S. mansoni antigen extracts. The frequency of these cells is increased in all individuals over the age of 50 years and only declines in positive individuals after 70 years of age. Analysis of either CD4? or CD8 ? cells after antigen stimulation show no significant increase in frequency of IFN-g in negative or in positive individuals of this age group, suggesting that the effect on CD16 cells is not T-cell dependent. Conclusion : Since production of IFN-g has been related to resistance to schistosome infection, our data suggest that age-associated changes in CD16 cells may play a role in controlling infection intensity in the elderly in S. mansoni endemic areas of Brazil.

show abstract

Section: Introductionmentioning

confidence: 93%

Production of interferon-γ by natural killer cells and aging in chronic human schistosomiasis

Speziali

Bethony

Martins‐Filho

et al. 2004

Mediators of Inflammation

View full text Add to dashboard Cite

show abstract

“…At the household level, spatial information on schistosomiasis can provide information on socioeconomic, behavioral, and genetic factors in parasite transmission and treat- ment because of the socioeconomic cohesion and associated exposure risk and health-seeking behavior of families (Berman et al 1994, Cairncross et al 1996, Bethony et al 2002. In addition, intensity of schistosomiasis infection has been found to decline with increasing distance between households and infective water sources (Kloos et al 1998, McClennon et al 2004.…”

Section: Schistosomiasis Prevalence and Egg Counts Remained Low One Ymentioning

confidence: 99%

The spatial distribution of Schistosoma mansoni infection before and after chemotherapy in the Jequitinhonha Valley in Brazil

Gazzinelli

Hightower²,

LoVerde

et al. 2006

Mem. Inst. Oswaldo Cruz

View full text Add to dashboard Cite

Schistosomiasis prevalence and egg counts remained low one year after chemotherapy in most households in a hyperendemic rural area in northern Minas Gerais but several distinct spatial patterns could be observed in relation to IgE levels and to a lesser extent to exposure risk (TBM) and type of water supply. An inverse relationship between pre-treatment household prevalence and egg counts on the one hand and post-treatment IgE levels on the other were noted in two of the five communities. Low exposure risk was associated with the low pre-treatment infection rates in the central village but did not contribute to the decline of infection rates after chemotherapy in the study area, as indicated by the significant increase in water contact during the posttreatment period (p < 0.0001). Distance between households and the streams and socioeconomic factors were also unimportant in predicting the spatial distribution of infection. These results are consistent with the production and antiparasitic effect of high levels of IgE in Schistosoma mansoni infection.Key words: schistosomiasis -chemotherapy -spatial clustering -IgE antibodies -exposure risk -nursing -Brazil Geographical Information Systems (GIS) are increasingly being used in epidemiological and ecological studies of schistosomiasis. Most studies, many of them using GIS in combination with remote sensing techniques, have been carried out at the regional level (Bavia et al. 1999, Brooker & Michael 2000a, Malone et al. 2001, Handzel et al. 2003. The World Health Organization (WHO) recently emphasized the need for studies at the community level in areas where schistosomiasis is gradually being controlled. This includes Brazil, where the national program is making inroads into the prevalence, intensity and pathology of schistosomiasis mostly through chemotherapy and safe water supplies, and where further environmental measures as well as health education have been called for (Katz 1998, WHO 2001.Schistosomiasis tends to cluster within communities, at both the neighborhood and household levels, due to the characteristic focality of risk behavior and transmission (Barreto 1991, Kloos et al. 1998, Bethony et al. 2004. At the household level, spatial information on schistosomiasis can provide information on socioeconomic, behavioral, and genetic factors in parasite transmission and treat- ment because of the socioeconomic cohesion and associated exposure risk and health-seeking behavior of families (Berman et al. 1994, Cairncross et al. 1996, Bethony et al. 2002. In addition, intensity of schistosomiasis infection has been found to decline with increasing distance between households and infective water sources (Kloos et al. 1998, McClennon et al. 2004.The effect of chemotherapy on the spatial distribution of schistosomiasis is poorly known. Different treatment strategies have been associated with fairly predictable reductions in pretreatment infection intensities and transmission levels in Kenya (Butterworth et al. 1991, Sturrock et al. 1994. Similarly, in Côte d'Ivoire...

show abstract

“…Accumulating evidence reveals novel early gene-environment interactions, which play dynamic roles in developing brains of children experiencing repeated enteric infections and diarrhea [7][8][9][10]. The genetic contributions may determine differential susceptibilities to infection or their outcomes, by affecting host-parasite responses, placing certain children at particularly high risk.…”

Section: Introductionmentioning

confidence: 99%

Role of apolipoprotein E4 in protecting children against early childhood diarrhea outcomes and implications for later development

et al. 2007

View full text Add to dashboard Cite

SummaryOur group and others have reported a series of studies showing that heavy burdens of diarrheal diseases in the formative first two years of life in children in urban shantytowns have profound consequences of impaired physical and cognitive development lasting into later childhood and schooling. Based on these previous studies showing that apolipoprotein E4 (APOE4) is relatively common in favela children, we review recent data suggesting a protective role for the APOE4 allele in the cognitive and physical development of children with heavy burdens of diarrhea in early childhood. Despite being a marker for cognitive decline with Alzheimer's and cardiovascular diseases later in life, APOE4 appears to be important for cognitive development under the stress of heavy diarrhea. The reviewed findings provide a potential explanation for the survival advantage in evolution of the thrifty APOE4 allele and raise questions about its implications for human development under life-style changes and environmental challenges.

show abstract

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

Cited by 46 publications

References 48 publications

Production of interferon-γ by natural killer cells and aging in chronic human schistosomiasis

Production of interferon-γ by natural killer cells and aging in chronic human schistosomiasis

The spatial distribution of Schistosoma mansoni infection before and after chemotherapy in the Jequitinhonha Valley in Brazil

Role of apolipoprotein E4 in protecting children against early childhood diarrhea outcomes and implications for later development

Contact Info

Product

Resources

About