Assessing feasibility of using Oral Fluid assay as Alternative method in the Detection of Rubella Virus-Specific IgM Antibodies in routine disease surveillance Programme in Kenya

Background: The WHO recommends the inclusion of rubella testing in the measles surveillance system. Laboratory diagnosis of measles and rubella virus infection is achieved by serological assay for specific IgM from a sample of blood drawn by vein puncture. This conventional method of sample collection is invasive and less acceptable. Aim: To assess feasibility of using oral fluid as an alternative method in the detection of rubella-virus specific IgM in routine surveillance of rubella Settings and Design: A prospective laboratory-based cross-sectional study using matched oral fluid and serum collected from emerging outbreaks of rash-like illnesses across Kenya. Methods and Material: Matching samples of 176 patients were investigated for IgM specific antibodies using enzyme linked immunosorbent assays. Statistical analysis used: The kappa (k) statistic was used to measure inter-observer variations. Results: The prevalence of rubella using serum and oral methods was 26.7% and 23.3% respectively. Sensitivity and specificity for rubella IgM in oral fluid when tested against the gold standard was 86% and 93% respectively.  Kappa statistic value was 0.80 suggesting substantial agreement between the two methods. Conclusion: The study showed that oral fluid method is a promising simple alternative, non-invasive and more acceptable specimen of choice for rubella diagnosis. The alternative method will be more applicable to disease surveillance programmes where clinical settings are varied. The advantage of this method of sample collection is ease and safety with minimum requirement for shipment to laboratory. These findings will support the entire disease surveillance system in Kenya and also can have extended use in conducting epidemiological studies. Key words: Oral fluid, serum, diagnosis, surveillance, prevalence, diseases, measles and rubell

Differing Burden and Epidemiology of Non-Typhi Salmonella Bacteremia in Rural and Urban Kenya, 2006–2009

BACKGROUND: The epidemiology of non-Typhi Salmonella (NTS) bacteremia in Africa will likely evolve as potential co-factors, such as HIV, malaria, and urbanization, also change. METHODS: As part of population-based surveillance among 55,000 persons in malaria-endemic, rural and malaria-nonendemic, urban Kenya from 2006-2009, blood cultures were obtained from patients presenting to referral clinics with fever ≥38.0°C or severe acute respiratory infection. Incidence rates were adjusted based on persons with compatible illnesses, but whose blood was not cultured. RESULTS: NTS accounted for 60/155 (39%) of blood culture isolates in the rural and 7/230 (3%) in the urban sites. The adjusted incidence in the rural site was 568/100,000 person-years, and the urban site was 51/100,000 person-years. In both sites, the incidence was highest in children <5 years old. The NTS-to-typhoid bacteremia ratio in the rural site was 4.6 and in the urban site was 0.05. S. Typhimurium represented >85% of blood NTS isolates in both sites, but only 21% (urban) and 64% (rural) of stool NTS isolates. Overall, 76% of S. Typhimurium blood isolates were multi-drug resistant, most of which had an identical profile in Pulse Field Gel Electrophoresis. In the rural site, the incidence of NTS bacteremia increased during the study period, concomitant with rising malaria prevalence (monthly correlation of malaria positive blood smears and NTS bacteremia cases, Spearman's correlation, p = 0.018 for children, p = 0.16 adults). In the rural site, 80% of adults with NTS bacteremia were HIV-infected. Six of 7 deaths within 90 days of NTS bacteremia had HIV/AIDS as the primary cause of death assigned on verbal autopsy. CONCLUSIONS: NTS caused the majority of bacteremias in rural Kenya, but typhoid predominated in urban Kenya, which most likely reflects differences in malaria endemicity. Control measures for malaria, as well as HIV, will likely decrease the burden of NTS bacteremia in Africa

Detection and localisation of picorna-like virus particles in tissues of Varroa destructor, an ectoparasite of the honey bee, Apis mellifera

Virus-like particles, 27nm in diameter, were observed in extracts of individual Varroa destructor mites and in sections of mite tissue. Application of a purification procedure resulted in virus preparations that were used to prepare an antiserum to detect the virus in individual mites. Immunohistology studies showed that the gastric caecae were heavily infected, whereas no immunostaining could be detected in other mite tissues or organs, like the salivary glands, brain, rectum or reproductive organs. By electron microscopy large aggregates of virus-like particles in para-crystalline lattices were found in cells of the gastric caecae. The particles, reminiscent to picorna-like viruses, occurred mainly in the cytoplasm, whereas some virus particles were sparsely scattered in vacuoles. Occasionally, particles were observed in membrane-bound vesicles or in long tubular membrane structures in the cytoplasm. The accumulation of the picorna-like virus particles in the cytoplasm and the presence of the virus in membrane structures give a strong indication that the virus replicates in the mite