Multiplex Real-time PCR Detection of Intestinal Protozoa in HIV-infected Children in Malawi: Enterocytozoon Bieneusi Is Common and Associated With Gastrointestinal Complaints and May Delay BMI (Nutritional Status) Recovery.

BACKGROUND: Intestinal protozoa are common opportunistic infections in HIV patients. Longitudinal studies on either the clinical relevance or the effect of immune reconstitution by antiretroviral therapy on intestinal protozoan infections in children are lacking however. This study investigates prevalence and clinical relevance of intestinal protozoa in HIV-infected Malawian children before and during their first year of antiretroviral treatment (ART). METHODS: Stool samples collected at enrolment and during follow-up were tested for nonopportunistic (Giardia lamblia, Dientamoeba fragilis, Entamoeba histolytica) and opportunistic protozoa (Enterocytozoon bieneusi, Encephalitozoon spp., Cryptosporidium spp. and Cystoisospora belli) using multiplex real-time polymerase chain reaction. Associations between infections and clinical symptoms were evaluated using univariate methods. RESULTS: Nonopportunistic and opportunistic protozoa were detected in 40% (14/35) and 46% (16/35) of children at baseline, respectively. E. bieneusi was the most prevalent protozoa (37%, 13/35) and associated with gastrointestinal complaints (43% in positive (10/13) versus 18% (4/22) in E. bieneusi-negative children, P = 0.001. Body mass index recovery during 12 months of ART was more commonly delayed in E. bieneusi-positive children (+0.29 +standard deviation 0.83) than E. bieneusi-negative children (+1.03 +standard deviation 1.25; P = 0.05). E. bieneusi was not detected after 12 months of ART. CONCLUSIONS: E. bieneusi was the most prevalent opportunistic intestinal protozoa, present in over a third of study participants before initiation of ART. Although all children cleared E. bieneusi after 12 months of ART, E. bieneusi was associated with gastrointestinal complaints and may delay body mass index recovery. Trials to assess effect of treatment of E. bieneusi on nutritional status should be considered in HIV-infected African children.

An Evaluation of Alternative Markers to Guide Initiation of Anti-retroviral Therapy in HIV-Infected Children in Settings where CD4 Assays are not Available.

OBJECTIVES: In settings where CD4 testing is not available, alternative markers to start paediatric anti-retroviral therapy (ART) could be used. A comprehensive evaluation of these markers has not been performed. METHODS: Prospective cross-sectional study of HIV-infected Malawian children not eligible for ART based on clinical criteria. Associations between CD4 and alternative markers [haemoglobin, total lymphocyte count (TLC), serum albumin, thrombocytes and growth parameters] were analysed, and accuracy of existing and new cut-offs were evaluated. RESULTS: In all, 417 children were enrolled. Of 261 children aged ≥5 years, 155 (59%) qualified to start ART using CD4. In this group, only TLC was associated with CD4 (p < 0.001). Sensitivity for TLC was 21% (95% CI: 15-29%), using World Health Organization cut-offs. Improved cut-offs increased sensitivity to 73% (95% CI: 65-80%), specificity 62% (95% CI: 52-72%). CONCLUSION: Clinical staging alone is an unreliable strategy to start ART in children. TLC is the only alternative marker for CD4, cut-offs need to be revised though.

Conventional and novel peripheral blood iron markers compared against bone marrow in Malawian children.

AIM: Iron deficiency is an important child health problem. Its diagnosis in areas of high infection exposure remains complicated as inflammation may interfere with the accuracy of peripheral iron markers. With this study, we aimed to validate the conventional iron markers and two novel iron markers, hepcidin and Red blood cell Size Factor (RSf), against the reference standard of iron status, bone marrow iron, in children living in an infectious setting. METHODS: We compared ferritin, soluble transferrin receptor, Soluble Transferrin Log-Ferritin Index (sTfR-F), mean cellular volume, mean cellular haemoglobin concentration, hepcidin and RSf, against bone marrow iron in 87 healthy Malawian children (6-66 months) scheduled for elective surgery. RESULTS: Of all children, 44.8% had depleted bone marrow iron stores. Using optimised cut-offs, ferritin (<18 µg/L) and sTfR-F (>1.85) best predicted depleted iron stores with a sensitivity/specificity of 73.7%/77.1% and 72.5%/75.0%, respectively. Hepcidin (<1.4 nmol/L) was a moderate sensitive marker (73.0%) although specificity was 54.2%; RSf poorly predicted depleted iron stores. CONCLUSIONS: We provide the first bone marrow-validated data on peripheral iron markers in African children, and showed ferritin and sTfR-F best predicted iron status. Using appropriately defined cut-offs, these indicators can be applied in surveillance and research. As their accuracy is limited for clinical purposes, more reliable iron biomarkers are still required in African children.