Isospora belli infection. A report of two cases in patients with AIDS

Initiating co-trimoxazole prophylaxis in HIV-infected patients in Africa: an evaluation of the provisional WHO/UNAIDS recommendations

OBJECTIVE

To evaluate the proposed WHO/UNAIDS criteria for initiating co-trimoxazole prophylaxis in adult HIV-infected patients in Africa [WHO clinical stages 2--4 or CD4 count < 500 x 10(6) /l or total lymphocyte count (TLC) equivalent].

DESIGN

Observational cohort study of 5-year follow-up.

SETTING

Adult HIV clinics, University of Cape Town, South Africa.

METHODS

Effect of prophylactic low dose co-trimoxazole (480 mg per day or 960 mg three times per week) on survival and morbidity was assessed in patients stratified by WHO clinical stage, CD4 T-lymphocyte count or TLC. Patients receiving antiretroviral therapy were excluded.

RESULTS

Co-trimoxazole reduced mortality [adjusted hazard ratio (AHR), 0.56; 95% confidence interval (CI), 0.33--0.85; P > 0.001] and the incidence of severe HIV-related illnesses (AHR, 0.52; 95% CI, 0.38--0.68; P < 0.001) in patients with evidence of advanced immune suppression on clinical (WHO stages 3 and 4) or laboratory assessment (TLC < 1250 x 10(6)/l or CD4 count < 200 x 10(6)/l). No significant evidence of efficacy was found in patients with WHO stage 2 or CD4 count 200--500 x 10(6)/l/TLC 1250--2000 x 10(6)/l. If we had applied the WHO/UNAIDS recommendations 88.3% of our patients would have received co-trimoxazole prophylaxis at their initial clinic visit.

CONCLUSION

Co-trimoxazole in HIV-infected adults from an area in which Pneumocystis carinii pneumonia is uncommon demonstrated a survival benefit consistent with previous randomized trials. Further studies are needed to assess the optimal time of commencement of prophylaxis, as widespread co-trimoxazole use will lead to increasing antimicrobial resistance to other major pathogens in Africa.

Pathways to the impairment of human nutritional status by gastrointestinal pathogens

Gastrointestinal pathogens are of three varieties, those that can, and often do, take the life of the host, those that infect transiently and rarely are life-threatening, and those (parasites) that establish a relatively prolonged residence or colonization of the host's alimentary tract. In the case of the second form, if infections are recurrent, both catabolic effects during the episode and failure to digest foods and/or absorb nutrients results. Similarly, catabolic wastage through activation of the acute phase response, and interference with the host's acquisition of nutrients by maldigestion, malabsorption, intestinal losses and competition with the parasite burden can impair growth and nutrition with helminthic infections. Growth and nutrition with respect to all of the macronutrients and virtually all of the micronutrients have been documented to be adversely affected by gastrointestinal pathogens. For its burgeoning importance as a worldwide health problem, both with the HIV virus as a direct intestinal pathogen and with the opportunistic gut infections occurring in the immunocompromised host, AIDS represents the emerging context of the impairment of nutritional status by intestinal pathogens.

Isosporiasis in the aboriginal population of Queensland

OBJECTIVE

To report on the endemicity of Isospora belli in Queensland.

DESIGN

A 10-year retrospective survey of data from routine parasitological surveillance of Queensland Aboriginal communities, by microscopic examination of preserved faecal specimens.

SETTING

The Aboriginal Health Programme of the Queensland Department of Health and Medical Services.

POPULATION

Children under 15 years of age from all the Aboriginal communities of Queensland.

RESULTS

Oocysts of I. belli were detected in 33 (0.2%) of a total of 17,642 faecal samples examined.

CONCLUSION

Isosporiasis is endemic in the Queensland Aboriginal population. It is likely to be more common than indicated, because the infection is difficult to diagnose, and the techniques used to identify the organism were not particularly sensitive. It is predicted that isosporiasis will be recognised with increasing frequency as a cause of diarrhoea in Aboriginal and white Australians who develop AIDS.