Field evaluation of a new antibody-based diagnostic for Schistosoma haematobium and S. mansoni at the point-of-care in northeast Zimbabwe

BACKGROUND: Rapid diagnostic tests (RDTs) for use at the point-of-care (POC) are likely to become increasingly useful as large-scale control programmes for schistosomiasis get underway. Given the low sensitivity of the reference standard egg count methods in detecting light infections, more sensitive tests will be required to monitor efforts aimed at eliminating schistosomiasis as advocated by the World Health Assembly Resolution 65.21 passed in 2012. METHODS: A recently developed RDT incorporating Schistosoma mansoni cercarial transformation fluid (SmCTF) for detection of anti-schistosome antibodies in human blood was here evaluated in children (mean age: 7.65 years; age range: 1-12 years) carrying light S. mansoni and S. haematobium infections in a schistosome-endemic area of Zimbabwe by comparison to standard parasitological techniques (i.e. the Kato-Katz faecal smear and urine filtration). Enzyme-linked immunosorbent assays (ELISAs) incorporating S. haematobium antigen preparations were also employed for additional comparison. RESULTS: The sensitivity of the SmCTF-RDT compared to standard parasitological methods was 100% while the specificity was 39.5%. It was found that the sera from RDT “false-positive” children showed significantly higher antibody titres in IgM-cercarial antigen preparation (CAP) and IgM-soluble egg antigen (SEA) ELISA assays than children identified by parasitology as “true-negatives”. CONCLUSIONS: Although further evaluations are necessary using more accurate reference standard tests, these results indicate that the RDT could be a useful tool for the rapid prevalence-mapping of both S. mansoni and S. haematobium in schistosome-endemic areas. It is affordable, user-friendly and allows for diagnosis of both schistosome species at the POC

Malarial infection among HIV Patients on Antiretroviral Therapy (ART) and those not on ART: A Case Study of Federal Medical Centre, Makurdi, Benue State, Nigeria

Malarial infection among patients on antiretroviral therapy (ART) attending Federal Medical Centre, Makurdi, Benue State was investigated between April and August 2008 to determine the level of malaria infection in HIV/AIDS patients on ART and those not on ART with respect to CD4+ counts, age and gender. A total of 1,080 HIV patients were examined (800 on ART and 280 not on ART considered as control). Questionnaire was administered to each participant to collect socio-demographic data. The Cytoflow, and thin and thick blood films were used to count CD4+  and conduct parasitological examination, respectively. Of the 800 HIV/AIDS patients on ART examined for malaria parasites, 20.5% (164/800) were found positive for malaria infection, while those not on ART had an infection rate of 63.9% (179/280). There was an association between the severity of malarial infection between patients not on ART and those on ART (χ2 14.05, p = 0.001). The age groups < 22 years, 23-29 years and 44-50 years recorded high prevalences of malaria with 66.7% (14/21), 67.9% (36/53) and 73.7% (14/19), respectively. Malarial infection was higher in patients on ART with CD4+ count less than 200/μl and 201-500/μl with 21.1% (72/342) and 22.9% (64/279), respectively. Female patients on ART showed higher infection rate (23.1%) than their male counterparts (17.4%).Keywords: Antiretroviral therapy, malaria parasites, CD4+, parasitological examination and socio-demographic dataNigerian Journal of Parasitology, Vol. 33 [1] March 2012, pp. 59-6

Performance of microhaematuria and proteinuria as measured by urine reagent strips in estimating intensity and prevalence of Schistosoma haematobium infection in Nigeria

AbstractObjectiveTo assess if microhaematuria and proteinuria as measured by reagent strips could estimate intensity of Schistosoma haematobium (S. haematobium) infection in endemic areas and evaluate their screening performance among children in Benue State, Nigeria.MethodsA total of 1 124 urine samples were collected, screened for microhaematuria and proteinuria using reagent strips (Combi 9) and results were compared to filtration technique, the gold standard method.ResultsA significant correlation was observed between microhaematuria (rho= 0.66, P<0.01), proteinuria (rho = 0.71, P<0.01) and intensity of S. haematobium eggs. Proteinuria had sensitivity of 95.7% and specificity of 67.2%, while microhaematuria had sensitivity of 64.8% and specificity of 89.6%. The proportion of false positive diagnoses was higher in proteinuria (19.2%) than microhaematuria (6.0%).ConclusionsThe findings suggest that use of urine reagent strips could potentially estimate intensity of S. haematobium infection and their performance to screen urinary schistosomiasis agreed with previous observations

Comparison of malaria p.f/Pan rapid diagnostic test device with field microscopy for the detection of Plasmodium species in Nigerian children

Malaria remains a serious public health and life threatening problem to children under five years in Nigeria despite the tremendous efforts made to control the disease in recent years. This study was conducted todetermine the prevalence of malarial infection, identify the species of Plasmodium and determine the performance of the Malaria P.f/Pan Rapid Diagnostic Test Device as compared to microscopy in screening clinical cases of malaria among children under five years in Gboko, Benue State, Nigeria. Malaria P.f/Pan Rapid Diagnostic Test Devices and staining technique were used to determine Plasmodia antigens and malaria parasites in blood respectively. The occurrence of malaria irrespective of the Plasmodia species was 20.4% among the children examined. There was a predominance of Plasmodium falciparum malaria 14.5% among the malaria cases diagnosed (x2 =8.93, p=0.002). No significant difference was observed between Malaria P.f / Pan RDTs (17.7%; 39/220) and microscopy (20.4%; 45/220) in screening malaria (x2 with Yates’ correction =178.5, p=0.57). The Malaria P.f/Pan RDT device recorded a sensitivity and specificity of 86.7%, CI (73.2%-94.9%) and 100%, CI (90.9%-100.0%) respectively when compared to microscopy the Gold Standard Technique. The study revealed that malaria is endemic with a predominance of P. falciparum among children under five years in Gboko, Nigeria. Both malaria P.f/Pan RDT devices and microscopy were comparable in screening malaria among the children. It is recommended that the use of Malaria P.f/Pan RDT devices should be encouraged in hospitals, though the combination of both methods will provide more accurate diagnosis.Keywords: malaria, RDT, children, Gboko, Nigeri