Morbidity in Schistosomiasis Mansoni in Relation to Intensity of Infection: Study of a Community in Machakos, Kenya *

Siongok, T. K. Arap; Handa, A; Houser, H. B.; Warren, Kenneth S.; Muller, A.; Mahmoud, Adel A. F.; Ouma, John H.

doi:10.4269/ajtmh.1976.25.273

Cited by 165 publications

(57 citation statements)

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“…Usually, hepatomegaly and intensity of infection are employed as the classic morbidity markers in schistosomiasis (Arap-Siongok et al 1976, Barreto & Loureiro 1984, Gryseels 1992). In our study, hepatomegaly below the costal margin was detected in similar percentages in in- fected and uninfected people.…”

Section: Discussionmentioning

confidence: 99%

Schistosomiasis mansoni in low transmission areas: abdominal ultrasound

Ruiz

Candia

Garassini

et al. 2002

Mem. Inst. Oswaldo Cruz

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Section: Discussionmentioning

confidence: 99%

Schistosomiasis mansoni in low transmission areas: abdominal ultrasound

Ruiz

Candia

Garassini

et al. 2002

Mem. Inst. Oswaldo Cruz

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“…Severe periportal fibrosis, however, develops in Ͻ10% of chronically infected individuals (1) for reasons that are not well understood. It has been suggested that periportal fibrosis most often develops in subjects with the heaviest or longest duration of infection (2)(3)(4)(5), that have a genetic predisposition (6 -8), or have coinfections such as viral hepatitis (9 -12).…”

Section: Repeated Exposure Induces Periportal Fibrosis Inmentioning

confidence: 99%

Repeated Exposure Induces Periportal Fibrosis inSchistosoma mansoni-Infected Baboons: Role of TGF-β and IL-4

Farah

Mola

Kariuki

et al. 2000

The Journal of Immunology

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Recently, we observed that repeated Schistosoma mansoni infection and treatment boost Th2-associated cytokines and TGF-β production in baboons. Other studies have shown that some chronically infected baboons develop hepatic fibrosis. Because TGF-β, IL-2, and IL-4 have been shown to participate in development of fibrosis in murine schistosomiasis, the present study examined whether repeated exposure stimulates hepatic fibrosis in olive baboons. To test this hypothesis, animals were exposed to similar numbers of S. mansoni cercariae given once or repeatedly. After 19 wk of infection, animals were cured with praziquantel and reinfected once or multiple times. Hepatic granulomatous inflammation and fibrosis were assessed from serial liver biopsies taken at weeks 6, 9, and 16 after reinfection and egg Ag (schistosome egg Ag)-specific cytokine production by PBMC were measured simultaneously. Periportal fibroblast infiltration and extracellular matrix deposition (fibrosis), angiogenesis, and biliary duct hyperplasia developed in some animals. The presence and amount of fibrosis directly correlated with the frequency of exposure. Fibrosis was not associated with adult worm or tissue egg burden. The amount of fibrosis correlated with increased schistosome egg Ag-driven TGF-β at 6, 9, and 16 wk postinfection (rs = 0.9, 0.8, and 0.54, respectively, all p < 0.01) and IL-4 production (p = 0.02) at 16 wk postinfection and not IFN-γ, IL-2, IL-5, or IL-10. These data suggest that repeated exposure is a risk factor for periportal fibrosis by a mechanism that primes lymphocytes to produce increased levels of profibrotic molecules that include TGF-β and IL-4.

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“…The decline appears to be more rapid in S. haematobium infection than in S. mansoni infection. Similar age prevalence relationships in schistosomiasis have been observed in some endemic areas (Pesigan, 1951;Clarke, 1967;Siongok et al, 1976).…”

Section: Discussionmentioning

confidence: 49%

“…Thick smear method (Kato and Miura, 1954) were used to detect S. mansoni ova in stool samples by some investigators (Cook et al, 1974;Warren et al, 1974;Siongok et al, 1976). In the present studies, however, the rationale to apply the MIFC method which was modified for schistosome ova detection by Ota and Sato (1957) to the examination of stool samples is that more than 1 g of sample can be examined by the concentration methods in contrast to 50 mg per slide by the thick smear method, and that the concentration method is, at least, a few times more sensitive than the smear method in spite of some ova missed in the process of concentration (Ota and Sato, 1957;Okabe et al, 1960;Iijima et al, 1962).…”

Section: Discussionmentioning

confidence: 99%

Prevalence of Human Schistosomiasis in the Taveta Area of Kenya, East Africa

Katamine

Siongok

Kawashima

et al. 1978

Jap. J. Trop. Med. Hyg.

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Abstract:A total of 963 individuals in three villages were examined for schistosomiasis by both skin test and schistosome ova detection in stool and urine in 1974. The antigen used for skin test was VBS adult S. japonicum antigen (1 : 10,000 dilution). Stool and urine samples were examined through the concentration methods. Egg-positive rate was 62.2 per cent in Jipe, 68.0 per cent in Eldoro, 69.6 per cent in Kivalwa. Jipe was infested mostly by S. mansoni, Kivalwa by S. haematobium and Eldoro by both two schistosomes. The egg-positive rate was higher in females than in males in Eldoro. In Jipe and Kivalwa, however, the differences in the rate between males and females were not statistically significant. The rate increased with age in children, reached a peak between the ages of 5 and 14 years and then decreased gradually. The positive rate of skin test was 76.4 per cent in total, higher than that of stool and urine examinations. The skin reaction was weak or absent among many egg-positive children. The skin-testpositive rate increased as the age advanced and reached 95 per cent in inhabitants from 40 years up. The positive rate of skin test was higher among males than females in Jipe. No significant difference in the rate between males and females was found in Eldoro and Kivalwa. Among the egg-positive subjects there was no significant difference in skin reaction between S. mansoni infection and S. haematobium infection. In 1975 stool and urine samples from Jipe, Kivalwa, Kuwahoma and Chala were examined. Kuwahoma proved to be infested by S. haematobium. In Chala schistosome infection was rare. There exist villages infested by S. mansoni and/or S. haematobium in the small area. It seems that VBS adult S. japonicum antigen for skin test and the concentration methods for stool and urine examinations are of use in the epidemiological survey in the areas where S. mansoni and/or S. haematobium infections are prevailing.

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Morbidity in Schistosomiasis Mansoni in Relation to Intensity of Infection: Study of a Community in Machakos, Kenya *

Cited by 165 publications

References 0 publications

Schistosomiasis mansoni in low transmission areas: abdominal ultrasound

Schistosomiasis mansoni in low transmission areas: abdominal ultrasound

Repeated Exposure Induces Periportal Fibrosis inSchistosoma mansoni-Infected Baboons: Role of TGF-β and IL-4

Prevalence of Human Schistosomiasis in the Taveta Area of Kenya, East Africa

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