Epidemiology and morbidity of Schistosoma mansoni infection in a fishing community along Lake Albert in Uganda

ABSTRACT The human host is continuously exposed to the egg and the adult worm developmental stages of Schistosoma mansoni during chronic infections with the parasite. To assess the cytokine responses induced by these different costimulating stages and how they are influenced by host age and infection intensity, whole blood samples from a cross-sectional cohort of 226 members of a Ugandan fishing community who had been resident in an area with high transmission of S. mansoni for the previous 10 years or from birth were stimulated with S. mansoni egg antigen (SEA) or worm antigen (SWA). SWA-specific gamma interferon (IFN-γ) production increased with age, and the levels of SWA- and SEA-specific interleukin 3 (IL-3) were weakly correlated with schistosome infection intensity. The production of most cytokines was little affected by age or infection intensity but was either SEA or SWA specific. One hundred thirty-two members of the cohort coproduced IL-5 and IL-13 specifically in response to SWA, whereas only 15 produced these cytokines, and at much lower levels, in response to SEA. IL-10, IL-4, and IFN-γ were also produced in response to SWA, whereas the response to SEA consisted almost exclusively of IL-10. Our results suggest that, in contrast to what has been described for the murine model of S. mansoni and during acute human infections, chronic intense exposure to and infection with S. mansoni in this cohort resulted in very low levels of response to SEA in vitro in the presence of a vigorous and mixed Th1-Th2 response to SWA.

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The relationship between age, sex, egg-count and specific antibody responses against Schistosoma mansoni antigens in a Ugandan fishing community

Tropical Medicine & International Health ◽

10.1046/j.1365-3156.2003.01056.x ◽

2003 ◽

Vol 8 (6) ◽

pp. 561-568 ◽

Cited By ~ 44

Author(s):

Cynthia W. A. Naus ◽

Mark Booth ◽

Frances M. Jones ◽

Jovanice Kemijumbi ◽

Birgitte J. Vennervald ◽

...

Keyword(s):

Schistosoma Mansoni ◽

Specific Antibody ◽

Antibody Responses ◽

Fishing Community ◽

The Relationship

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Adult resistance to schistosomiasis mansoni: age-dependence of reinfection remains constant in communities with diverse exposure patterns

Parasitology ◽

10.1017/s0031182098003576 ◽

1999 ◽

Vol 118 (1) ◽

pp. 101-105 ◽

Cited By ~ 100

Author(s):

N. B. KABATEREINE ◽

B. J. VENNERVALD ◽

J. H. OUMA ◽

J. KEMIJUMBI ◽

A. E. BUTTERWORTH ◽

...

Keyword(s):

Schistosoma Mansoni ◽

Fishing Communities ◽

Fishing Community ◽

Age Dependence ◽

Water Contact ◽

Schistosomiasis Mansoni ◽

Exposure Patterns ◽

Stark Contrast

In a fishing community on Lake Albert in Uganda the pattern of intensity of Schistosoma mansoni infection 6 months after treatment with praziquantel was found to be very similar to reinfection patterns seen in previously studied endemic communities: the profile peaks sharply at around the age of 10 years falling away rapidly to much lower levels in adults. This is in stark contrast to the patterns of water contact, which differ greatly between fishing and non-fishing communities. On Lake Albert, adults appear to be more heavily exposed than children. From these observations we conclude that adults are physiologically (perhaps immunologically) more resistant to infection after treatment than children.

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Rapid clearance of Schistosoma mansoni circulating cathodic antigen after treatment shown by urine strip tests in a Ugandan fishing community – Relevance for monitoring treatment efficacy and re-infection

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0006054 ◽

2017 ◽

Vol 11 (11) ◽

pp. e0006054 ◽

Cited By ~ 7

Author(s):

Anna O. Kildemoes ◽

Birgitte J. Vennervald ◽

Edridah M. Tukahebwa ◽

Narcis B. Kabatereine ◽

Pascal Magnussen ◽

...

Keyword(s):

Schistosoma Mansoni ◽

Treatment Efficacy ◽

Fishing Community ◽

Rapid Clearance ◽

Monitoring Treatment ◽

Urine Strip

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The acceptability and safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and soil-transmitted helminthiasis in children aged 1–4 years in Uganda

Parasitology ◽

10.1017/s0031182011000138 ◽

2011 ◽

Vol 138 (12) ◽

pp. 1586-1592 ◽

Cited By ~ 11

Author(s):

HARRIET NAMWANJE ◽

NARCIS B. KABATEREINE ◽

ANNETTE OLSEN

Keyword(s):

Clinical Trial ◽

Schistosoma Mansoni ◽

Limited Information ◽

Fishing Community ◽

Serious Adverse Events ◽

Small Children ◽

School Aged Children ◽

Safety Studies ◽

Stool Samples ◽

Soil Transmitted Helminthiasis

SUMMARYObjective. There is limited information on the acceptability and safety of praziquantel for treatment of schistosomiasis in children below the age of four years. In addition, although mebendazole has been extensively used together with praziquantel against infections with schistosomiasis and soil-transmitted helminthiasis (STH) in school-aged children, no specific acceptability or safety studies have been published on this drug combination in younger children. Methods. A randomized clinical trial was conducted to determine the safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and STH in children aged 1 to 4 years. Results. A total of 596 children from Bwondha fishing community in Mayuge district and Wang-Kado fishing community in Nebbi district were investigated using duplicate Kato-Katz thick smears of two stool samples and 130 (21·8%) were found infected with S. mansoni. Of these, 19·2% (25) had heavy intensity of infections. Of the infected children, 82 were included and randomised into praziquantel (40 mg/kg) + mebendazole (500 mg) or praziquantel (40 mg/kg) alone. Conclusion. Many symptoms were reported before treatment while very few were reported after treatment and all on treatment day. No serious adverse events were reported or observed after treatment. Praziquantel with or without mebendazole was well tolerated in small children in the study area.

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Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156791 ◽

1989 ◽

Vol 47 ◽

pp. 962-963

Author(s):

Betty Ruth Jones ◽

Steve Chi-Tang Pan

Keyword(s):

Nervous System ◽

Life Cycle ◽

Schistosoma Mansoni ◽

Snail Host ◽

Complex Life Cycle ◽

Rational Approach ◽

Effective Control ◽

The Social ◽

Social And Economic Development ◽

Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

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