Immuno-epidemiology of uro-genital schistosomiasis : focusing on atopy and pre-school age children
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Date
30/11/2012Author
Rujeni, Nadine
Metadata
Abstract
Urogenital schistosomiasis, due to Schistosoma haematobium, is one of the helminth
infections of public health importance in sub-Saharan Africa where children carry the
heaviest burden of infection. Treatment with the drug praziquantel is the only widely
available tool for control. Current schistosome control programs are essentially
school-based and exclude younger pre-school children. However, increasing reports
of significant infection levels in this age group call for the inclusion of these young
children in control programs.
The hygiene hypothesis suggests that helminth infections, including schistosome
infection, may protect against atopy, implying that helminth eradication may carry a
detrimental burden of immune disorders. However, this conjecture is controversial.
This study was designed to investigate the relationship between schistosome infection
and atopy. In a comparative epidemiological approach between two schistosome
endemic areas with differing infection levels, it is shown that atopy is inversely
associated with current schistosome infection intensity but not with cumulative
history of infection. This inverse relationship was subsequently shown to be
associated with the levels of soluble CD23, the low affinity IgE receptor, but not with
the polyclonal IgE stimulation.
However, while praziquantel treatment was associated with an increase in
schistosome-specific responses, a decline in atopic responses was observed in these
communities, suggesting that treatment differentially affect anti-schistosome and
atopic responses. In addition, the study has shown that praziquantel treatment of preschool
age children increases, quantitatively and qualitatively, their schistosome-specific
antibody responses purportedly associated with resistance to schistosome
infection/reinfection.