Background In order to protect health workers from SARS-CoV-2, there is need to characterise the different types of patient facing health workers. Our first aim was to determine both the infection and seroprevalence of SARS-COV-2 in health workers. Our second aim was to evaluate the occupational and demographic predictors of seropositivity to inform the country’s infection prevention and control (IPC) strategy. Methods and principal findings We invited 713 staff members at 24 out of 35 health facilities in the City of Bulawayo in Zimbabwe. Compliance to testing was defined as the willingness to uptake COVID-19 testing by answering a questionnaire and providing samples for both antibody testing and PCR testing. SARS-COV-2 antibodies were detected using a rapid diagnostic test kit and SAR-COV-2 infection was determined by real-time (RT)- PCR. Of the 713 participants, 635(89%) consented answering the questionnaire and providing blood sample for antibody testing while 560 (78.5%) agreed to provide nasopharyngeal swabs for the PCR COVID-19 testing. Of the 635 people (aged 18–73) providing a blood sample 39.1% reported a history of past COVID-19 symptoms while 14.2% reported having current symptoms of COVID-19. The most-prevalent co-morbidity among this group was hypertension (22.0%) followed by asthma (7.0%) and diabetes (6.0%). The SARS-CoV-2 sero-prevalence was 8.9%. Of the 560 participants tested for SARS-CoV-2 infection, 2 participants (0.36%) were positive for SAR-CoV-2 infection by PCR testing. None of the SARS-CoV-2 antibody positive people were positive for SAR-CoV-2 infection by PCR testing. Conclusion and interpretation In addition to clinical staff, several patient-facing health workers were characterised within Zimbabwe’s health system and the seroprevalence data indicated that previous exposure to SAR-CoV-2 had occurred across the full spectrum of patient-facing staff with nurses and nurse aides having the highest seroprevalence. Our results highlight the need for including the various health workers in IPC strategies in health centres to ensure effective biosecurity and biosafety.

IntroductionTuberculosis remains the leading causes of death worldwide with frequencies of mutations in rifampicin and isoniazid resistant Mycobacterium tuberculosis isolates varying according to geographical location. There is limited information in Zimbabwe on specific antibiotic resistance gene mutation patterns in MTB and hence, increased rate of discordant results and mortality due to inappropriate antibiotic prescriptions. The rpoB and katG genes molecular markers are used for detecting rifampicin and isoniazid resistance respectively. Some mutations within these gene sequences are associated with drug resistance as they directly alter gene function. The objectives of this research was to determine the drug resistance profiles in M. tuberculosis isolates that are phenotypically resistant but not detected by the GeneXpert and MTBDRplus kit and also to detect mutations in the rpoB and katG genes which are not detected by the Hain Genotype MTBDRplus kit and GeneXpert diagnosis.MethodsPCR was used for the amplification of the rpoB and katG genes from MTB isolates collected from human clinical samples between 2008 and 2015. The genes were sequenced and compared to the wild type MTB H37Rv rpoB (accession number L27989) and kat G genes (KP46920), respectively. Sequence analysis results were compared to genotyping results obtained from molecular assays and culture results of all isolates.ResultsThe most frequent mutation responsible for rifampicin resistance was (25/92) S531L that was detected by using all molecular assays. Some inconsistencies were observed between phenotypic and genotypic assay results for both katG and rpoB genes in 30 strains. For these, eight codons; G507S, T508A, L511V, del513-526, P520P, L524L, R528H, R529Q and S531F were novel mutations. In addition, the I572P/F, E562Q, P564S, and Q490Y mutations were identified as novel mutations outside the rifampicin resistance determining region. In katG gene, amino acid changes to threonine, asparagine and isoleucine exhibited high degrees of polymorphism such as V473N, D311N, and L427I. The R463L (20/92) amino acid substitution was most common but was not associated with isoniazid resistance.ConclusionThese finding indicate that molecular assay kit diagnosis that is based on the rpoB and katG genes should be improved to cater for the genetic variations associated with the geographic specificity of the target genes and be able to detect most prevalent mutations in different areas.

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Paramphistomes are parasites of domestic and wild ruminants, the effects of which in animal health remain underestimated. Very few studies in Africa have been done using molecular techniques to resolve situations associated with taxonomical groupings and epidemiology of these parasites. In this study, the genetic variability of nine representative paramphistome isolates collected from southern African countries, namely Botswana, South Africa, Zambia and Zimbabwe, was assessed using both morphological and internal transcribed spacer 2 (ITS2) rDNA sequence data. Morphological characterization and identification were carried out using median sagittal sections of the paramphistomes. DNA of the individual paramphistomes was isolated, the ITS2 rDNA was amplified, purified and sequenced. The sequences were submitted to GenBank, which assigned them the following accession numbers: KP639631, KP639630, KP639632, KP639633, KP639634, KP639635, KP639636, KP639637 and KP639638. These sequences were used for phylogenetic analysis using MEGA 6. Morphological characterization revealed three species of paramphistomes belonging to three different sub-families: one Stephanopharynx compactus isolate, a member of the Stephanopharyngidae sub-family; one Carmyerius dollfusi isolate, a member of the Gastrothylacidae sub-family; and seven Calicophoron microbothrium isolates belonging to the Paramphistomidae sub-family. ITS2 sequence analysis using BlastN results indicated that this is the first report of S. compactus (KP639630) and C. dollfusi (KP639636). Phylogenetic reconstruction of the paramphistome isolates revealed three separate clades representing the three species. However, the clade with all the C. microbothrium isolates was the only one that was supported by a higher bootstrap value of 92%, although there was no differentiation of the isolates according to geographical locations. The low divergence values on the ITS2 sequences of the C. microbothrium isolates indicate that ITS rDNA sequences can be used as a molecular tool to infer knowledge for resolving taxonomic groupings.

Ruminant herbivores utilize a symbiotic relationship with microorganisms in their rumen to exploit fibrous foods for nutrition. We report the metagenome sequences of the greater kudu (Tragelaphus strepsiceros) rumen digesta, revealing a diverse community of microbes and some novel hydrolytic enzymes.