Cryptosporidium parvum and Isopora belli infections among patients with and without diarrhoea

Objective: To assess the importance of Cryptosporidium parvum and Isospora belli infections as a cause of diarrhoea among patients admitted to the Medical Wards in Queen Elizabeth Central Hospital (QECH) in Blantyre, Malawi. Design: Prospective case control study. Subjects: One hundred and twenty one patients with diarrhoea and 122 patients without diarrhoea. Main outcome measures: Demonstration of C. parvum and I. belli oocysts by examination of at least one stool sample per patient using phenol auramine-O-fluorescence staining and an immuno-fluorescent assay with monoclonal antibodies against Cryptosporidium, seropositivity for HIV and AIDS. Results: In 22% of the patients with diarrhoea an infection with C. parvum or I. belli was found. Thirteen (11%) of them had a C. parvum and 14 (12%) an I. belli infection; a mixed infection was found in one patient. In the control group, three (3%) C. parvum and three (3%) I. belli infections were seen. The prevalence of both infections was very significantly higher in the cohort of diarrhoea patients than in the controls, 13/108 versus 3/119 (p=0.0099) for C. parvum, and 14/107 versus 3/119 (p=0.0056) for I. belli. Infections were only seen in HIV positive patients. Two hundred and four (84%) patients were HIV positive and 145 (60%) of them had AIDS. Conclusions: C. parvum and I. belli infections are a significant cause of diarrhoea among medical in-patients at QECH. Examinations of stool specimen for parasites among hospitalised patients with diarrhoea provide data for a more appropriate management. East African Medical Journal Vol.80(8) 2003:398-40

Susceptibility of Anopheles campestris-like and Anopheles barbirostris species complexes to Plasmodium falciparum and Plasmodium vivax in Thailand

Nine colonies of five sibling species members of Anopheles barbirostris complexes were experimentally infected with Plasmodium falciparum and Plasmodium vivax. They were then dissected eight and 14 days after feeding for oocyst and sporozoite rates, respectively, and compared with Anopheles cracens. The results revealed that Anopheles campestris-like Forms E (Chiang Mai) and F (Udon Thani) as well as An. barbirostris species A3 and A4 were non-potential vectors for P. falciparum because 0% oocyst rates were obtained, in comparison to the 86.67-100% oocyst rates recovered from An. cracens. Likewise, An. campestris-like Forms E (Sa Kaeo) and F (Ayuttaya), as well as An. barbirostris species A4, were non-potential vectors for P. vivax because 0% sporozoite rates were obtained, in comparison to the 85.71-92.31% sporozoite rates recovered from An. cracens. An. barbirostris species A1, A2 and A3 were low potential vectors for P. vivax because 9.09%, 6.67% and 11.76% sporozoite rates were obtained, respectively, in comparison to the 85.71-92.31% sporozoite rates recovered from An. cracens. An. campestris-like Forms B and E (Chiang Mai) were high-potential vectors for P. vivax because 66.67% and 64.29% sporozoite rates were obtained, respectively, in comparison to 90% sporozoite rates recovered from An. cracens

Een epidemische verheffing van cryptosporidiose in Nederland

Naar aanleiding van een epidemische verheffing van cryptosporidiose in de nazomer van 1995, is in augustus en september 1995 een prevalentiestudie uitgevoerd in vijf laboratoria in het land op basis van onderzoek bij 1495 patienten bij wie de huisarts gastroenteritis had geconstateerd. Met behulp van telefonische interviews werd tevens een patient-controle onderzoek uitgevoerd onder 71 patienten uit de regio's Spijkenisse/Rotterdam en Haarlem en onder 138 controlepersonen die waren gematched op leeftijd, geslacht en woonplaats. De prevalentie van Cryptosporidium in faecesmonsters in augustus en september was 5%-14% in de vijf laboratoria. De prevalentie was het hoogst in de jongste leeftijdsgroepen. Eind september was de prevalentie in de laboratoria in Spijkenisse en Haarlem sterk afgenomen. Uit het patient-controle-onderzoek bleek dat een infectie met Cryptosporidium geassocieerd was met contact met diarrheepatienten in het huishouden (odds ratio (OR) 3,7), zwemmen in een zwembad (OR 2,5) en bekendheid met chronische buikklachten (OR 3,2). Voor de regio Haarlem en omstreken werd ook een associatie waargenomen met het bezoeken aan kinderdagverblijven (OR 3,6). Uit de resultaten blijkt dat er in augustus/september 1995 in enkele delen van Nederland een epidemische verheffing van cryptosporidiose was. Een toename van cryptosporidiose treedt mogelijk iedere zomer op, maar de verheffing in 1995 was veel hoger dan in voorgaande jaren. Persoon-op-persoon transmissie, hetzij direct via contact met een diarrheepatient in het huishouden of bezoek aan kinderdagverblijven, hetzij indirect via zwemmen in een zwembad, lijkt een belangrijke oorzaak te zijn geweest van de waargenomen epidemische verheffing. Om een beter inzicht in omvang van en veranderingen in de prevalentie van cryptosporidiose te krijgen, wordt aanbevolen om in een aantal geselecteerde laboratoria surveillance van cryptosporidiose uit te voeren.Two studies have been carried out during an outbreak of cryptosporidiosis in the Netherlands in the late summer of 1995. A Cryptosporidium prevalence study was conducted in five laboratories in the country among 1495 patients who consulted a general practitioner for complaints of gastroenteritis. At the same time a case-control study was carried out among 71 cases of cryptosporidiosis and 138 matched controls in the Spijkenisse/Rotterdam area and the Haarlem area. Cryptosporidium was isolated in 5-14% of stool specimens in the five laboratories in the late summer of 1995. The prevalence was highest in the youngest age-groups ; sex differences were not observed. Cryptosporidiosis was associated with household contact with a person with diarrhoea (odds ratio (OR) 3.7), swimming in a swimming pool (OR 2.5), recurrent gastrointestinal disease (OR 3.2) and attendance of day care centres in the Haarlem area (OR 3.6). These results suggest that person-to-person transmission has played a major role in the observed increase in cryptosporidiosis in the late summer of 1995. An increase of cryptosporidiosis may occur every summer ; however, the increase in the summer of 1995 appears to have been extreme. It is recommended to incorporate Cryptosporidium-specific testing in the routine examinations of diarrhoeal stool specimens in selected laboratories, in order to study trends in the prevalence of cryptosporidiosis.IGZ DG