Comparing reliability of skin microfilarial load with first internal transcribed spacer primers DNA amplification in monitoring onchocerciasis treatment control

Treatment compliance is a serious challenge to community-directed treatment intervention (CDTI) targeting onchocerciasis eradication. Isolated cases of active infections could jeopardise decision to stop mass drug distribution. Onchocerciasis co-endemicity with lymphatic filariasis in the study-area informed the use of primers capable of differentiating sympatric infections in a single assay. The study-population was hitherto found to be negative for presence of skin microfilaria. DNA extracted from skin snips of patients (n=63) comprised of males, n=21 and females, n=42 were analysed using 18S first internal transcribed spacer (ITS1) in polymerase chain reaction (PCR) assay. Amplified DNA sequences were subjected to basic local alignment search tool. Spectrophotometric analysis of DNA concentrations ranged between 1.5- and 24.5 Nano gram (ng) and the two positive controls (adult worm DNA extract) were 10.5 and 105 ng at 260 nanometer (nm) wave length. The 260/ 280 nm ratios were between 1.44 and 1.68. Four samples (6.35%), two males and two females, and the two positive controls showed PCR amplification products. Two of the positive samples indicated double bands in an agarose gel electrophoregram with molecular weight of 350 and 500 base pairs (bp), while two had single band of 350bp, which is within the expected Mw range of 344 bp for Onchocerca volvulus. The double bands may not be due to unspecific amplification. Moreover, the DNA sequence of a sample had 69.1% homology with control sequence but not with O. volvulus sequences available in the GenBank database. This study underscored the need to assess effectiveness of CDTI with highly sensitive test and not depend on microscopy of emerged microfilaria from skin snips. Whether the DNA was from dead or living microfilaria remained a conjecture.Keywords: Skin microfilaria; DNA sequences.

Prevalence of endoparasites of field crickets (Brachytrupes membranaceous) in the eastern zone of Kogi State, north-central, Nigeria

Field crickets belong to the family; Gryllidae (insect: orthoptera), with flattened bodies and long antennae. They are omnivores and scavengers that normally feed on organic materials as well as decaying plant materials. A survey of the endoparasites of field crickets (Brachytrupes membranaceous) in the eastern zone of Kogi State, north-central Nigeria, was undertaken between April and June, 2016. A total of 150 field crickets (Brachytrupes membranaceous) were collected at nine locations and were dissected in petriplates. The midgut region of the alimentary canal dissected and examined for parasites. Out of the 150 samples examined, 64 (42.6%) had different types of parasites. The gut parasites encountered were 14(9.3%) Spinochordodes sp., and 50 (33.3%) Paragordius sp. The highest prevalence was observed in May, while the male Field Crickets were most affected. The results observed in the present study suggest that field crickets normally consumed as a special delicacy in this area, might be a potential reservoir for zoonotic parasites. There is need for intensive public health enlightenment on the danger of consuming raw or improperly prepared field crickets.Keywords: Crickets; helminthes; parasites; eastern Kogi; Nigeri

Genetic studies in the nigerian population implicate an MSX1 mutation in complex oral facial clefting disorders

BACKGROUND: Orofacial clefts are the most common malformations of the head and neck with a World-wide prevalence of 1/700 births. They are commonly divided into CL(P) and CP based on anatomical, genetic and embryological findings. A Nigerian craniofacial anomalies study “NigeriaCRAN” was set up in 2006 to investigate the role of gene-environment interaction in the etiology of orofacial clefts in Nigeria. SUBJECTS AND METHODS: DNA isolated from saliva from the Nigerian probands was used for genotype association studies and direct sequencing on the cleft candidate genes: MSX1, IRF6, FOXE1, FGFR1, FGFR2, BMP4, MAFB, ABCA4, PAX7 and VAX1, and the chromosome 8q region. RESULTS: A missense mutation A34G in MSX1 was observed in nine cases and four hap map controls. No other apparent etiologic variations were identified. A deviation from HWE was observed in the cases (p= 0.00002). There was a significant difference between the affected side for unilateral CL (p=0.03) and, between bilateral clefts and clefts on either side (p=0.02). A significant gender difference was also observed for CP (p=0.008). CONCLUSIONS: The replication of a mutation previously implicated in other populations suggests a role for the MSX1 A34G variant in the etiology of CL(P)

Astrocytic and microglial response and histopathological changes in the brain of horses with experimental chronic Trypanosoma evansi infection Resposta astrocítica e microglial e alterações histopatológicas no sistema nervoso central de eqüinos infectados cronicamente com Trypanosoma evansi

This study aimed to characterize astrocytic and microglial response in the central nervous system (CNS) of equines experimentally infected with T. evansi. The experimental group comprised males and females with various degrees of crossbreeding, ages between four and seven years. The animals were inoculated intravenously with 10(6) trypomastigotes of T. evansi originally isolated from a naturally infected dog. All equines inoculated with T. evansi were observed until they presented symptoms of CNS disturbance, characterized by motor incoordination of the pelvic limbs, which occurred 67 days after inoculation (DAI) and 124 DAI. The animals in the control group did not present any clinical symptom and were observed up to the 125th DAI. For this purpose the HE histochemical stain and the avidin biotin peroxidase method was used. Lesions in the CNS of experimentally infected horses were those of a wide spread non suppurative meningoencephalomyelitis.The severity of lesions varied in different parts of the nervous system, reflecting an irregular distribution of inflammatory vascular changes. The infiltration of mononuclear cells was associated with anisomorphic gliosis and reactive microglia was identified. The intensity of the astrocytic response in the CNS of the equines infected by T. evansi characterizes the importance of the performance of these cells in this trypanosomiasis. The characteristic gliosis observed in the animals in this experiment suggests the ability of these cells as mediators of immune response. The parasite, T. evansi, was not identified in the nervous tissues.<br>Este estudo objetivou caracterizar a participação astrocítica e microglial no sistema nervoso central (SNC) de eqüinos experimentalmente infectados com T. evansi. O grupo experimental foi formado por machos e fêmeas com vários graus de cruzamentos e idade variando entre quatro e sete anos. Os animais foram inoculados com 10(6) tripomastigotas de T. evansi, originalmente isolada de um cão infectado naturalmente. Todos os eqüinos inoculados foram observados até o aparecimento dos sintomas neurológicos, caracterizados por incoordenação motora dos membros pélvicos, o qual ocorreu entre 67 e 124 dias após a inoculação (DPI). Os animais do grupo controle não apresentaram sinais clínicos e foram observados até o 125º DPI. Para este propósito, foram utilizados os métodos histoquímicos (HE) e imunoistoquímicos do complexo avidina-biotina peroxidase (ABC). A lesão no sistema nervoso central (SNC) dos eqüinos infectados com T. evansi foi caracterizada como meningoencefalomielite não supurativa. A gravidade das lesões variou em diferentes segmentos do SNC, refletindo distribuição irregular das alterações vasculares. Infiltrado perivascular e meníngeo foi associado a gliose anisomórfica e microgliose reativa. A intensidade da resposta astrocítica no SNC dos equinos infectados com T. evansi caracteriza a importância da performance destas células nas tripanossomíases. A gliose observada nos animais deste experimento sugerem a habilidade destas células como mediadoras da resposta imune. T. evansi não foi identificado no parênquima do SNC

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

The past 2 years, during which waves of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants swept the globe, have starkly highlighted health disparities across nations. Tegally et al. show how the coordinated efforts of talented African scientists have in a short time made great contributions to pandemic surveillance and data gathering. Their efforts and initiatives have provided early warning that has likely benefited wealthier countries more than their own. Genomic surveillance identified the emergence of the highly transmissible Beta and Omicron variants and now the appearance of Omicron sublineages in Africa. However, it is imperative that technology transfer for diagnostics and vaccines, as well the logistic wherewithal to produce and deploy them, match the data-gathering effort