Your search found 2 Results
Improving control of African schistosomiasis: towards effective use of rapid diagnostic tests within an appropriate disease surveillance model.
Transactions of the Royal Society of Tropical Medicine and Hygiene. 2009 Apr; 103(4):325-32.Contemporary control of schistosomiasis is typically reliant upon large-scale administration of praziquantel (PZQ) to school age children. Whilst PZQ treatment of each child is inexpensive, the direct and indirect costs of preventive chemotherapy for the whole school population are more substantive and, at the national level where many schools are targeted, maximising cost effectiveness and the health impact are essential requirements for ensuring longer-term sustainability (i.e. >5 years). To this end, the WHO has issued a set of treatment guidelines, inclusive of re-treatment schedules, such that, where possible, treatment decisions by school are based upon local disease prevalence as determined by parasitological and/or questionnaire methods. As each diagnostic method has known shortcomings, presumptive treatment of at-risk schools may initially be preferred, especially if the existing infrastructure for disease surveillance is poor. It is against this background of school-based preventive chemotherapy that a rapid diagnostic test (RDT) for schistosomiasis is most urgently needed, not only to improve initial disease surveillance but also to focus drug delivery better through time. In this paper, the development, evaluation and application of selected diagnostic tests are reviewed to identify barriers that impede progress, foremost of which is that a new disease surveillance and evaluation model is required where the in-country price of each RDT ideally needs to be less than US$1 to be cost effective both in the short- and long-term perspective.
Validation of 2006 WHO prediction scores for true HIV infection in children less than 18 months with a positive serological HIV test.
PloS One. 2009; 4(4):e5312.INTRODUCTION: All infants born to HIV-positive mothers have maternal HIV antibodies, sometimes persistent for 18 months. When Polymerase Chain Reaction (PCR) is not available, August 2006 World Health Organization (WHO) recommendations suggest that clinical criteria may be used for starting antiretroviral treatment (ART) in HIV seropositive children <18 months. Predictors are at least two out of sepsis, severe pneumonia and thrush, or any stage 4 defining clinical finding according to the WHO staging system. METHODS AND RESULTS: From January 2005 to October 2006, we conducted a prospective study on 236 hospitalized children <18 months old with a positive HIV serological test at the national reference hospital in Kigali. The following data were collected: PCR, clinical signs and CD4 cell count. Current proposed clinical criteria were present in 148 of 236 children (62.7%) and in 95 of 124 infected children, resulting in 76.6% sensitivity and 52.7% specificity. For 87 children (59.0%), clinical diagnosis was made based on severe unexplained malnutrition (stage 4 clinical WHO classification), of whom only 44 (50.5%) were PCR positive. Low CD4 count had a sensitivity of 55.6% and a specificity of 78.5%. CONCLUSION: As PCR is not yet widely available, clinical diagnosis is often necessary, but these criteria have poor specificity and therefore have limited use for HIV diagnosis. Unexplained malnutrition is not clearly enough defined in WHO recommendations. Extra pulmonary tuberculosis (TB), almost impossible to prove in young children, may often be the cause of malnutrition, especially in HIV-affected families more often exposed to TB. Food supplementation and TB treatment should be initiated before starting ART in children who are staged based only on severe malnutrition.