Prevalence and risk factors of bovine tuberculosis in slaughtered cattle, Malawi.

Bovine tuberculosis (bTB) is an infectious disease with significant socioeconomic, animal, and public health impacts. However, the prevalence of bTB remains largely unclear in Malawi due to a paucity of information. Additionally, the existence of multiple risk factors is postulated to enhance bTB transmission in animals. A cross-sectional survey to estimate the prevalence of bTB, animal characteristics and identify associated risk factors was conducted from slaughtered cattle at three major regional abattoirs (southern, central and northern regions) in Malawi. Out of a total of 1547 cattle examined, 154 (9.95%) had bTB-like lesions in various visceral organs and lymph nodes; one sample per animal was collected, processed, and cultured in the in the BACTEC Mycobacterial growth indicator tube (MGIT) 960 system. From the 154 cattle that showed tuberculous like lesions, only 112 were positive on MGIT and 87 were confirmed to have M. bovis based on multiplex PCR. Cattle from the southern region (odds ratio (OR) = 1.96, 95% CI: 1.03-3.85) and central region (OR = 2.00, 95% CI: 1.16-3.56) were more likely presented with bTB-like lesions at slaughter than from the northern region. The risk of having bTB-like lesions was higher in females (OR = 1.51, CI: 1.00-2.29), older cattle (OR = 2.17, CI: 1.34-3.37), and crossbreeds (OR = 1.67, 95% CI: 1.12-2.47) than in males, younger animals, and Malawi Zebu breed, respectively. The high prevalence of bTB is of critical concern and necessitates active surveillance and strengthening of the current control strategies under a One Health (OH) approach at the animal-human interface.

An international, interlaboratory ring trial confirms the feasibility of an extraction-less "direct" RT-qPCR method for reliable detection of SARS-CoV-2 RNA in clinical samples.

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is used worldwide to test and trace the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). "Extraction-less" or "direct" real time-reverse transcription polymerase chain reaction (RT-PCR) is a transparent and accessible qualitative method for SARS-CoV-2 detection from nasopharyngeal or oral pharyngeal samples with the potential to generate actionable data more quickly, at a lower cost, and with fewer experimental resources than full RT-qPCR. This study engaged 10 global testing sites, including laboratories currently experiencing testing limitations due to reagent or equipment shortages, in an international interlaboratory ring trial. Participating laboratories were provided a common protocol, common reagents, aliquots of identical pooled clinical samples, and purified nucleic acids and used their existing in-house equipment. We observed 100% concordance across laboratories in the correct identification of all positive and negative samples, with highly similar cycle threshold values. The test also performed well when applied to locally collected patient nasopharyngeal samples, provided the viral transport media did not contain charcoal or guanidine, both of which appeared to potently inhibit the RT-PCR reaction. Our results suggest that direct RT-PCR assay methods can be clearly translated across sites utilizing readily available equipment and expertise and are thus a feasible option for more efficient COVID-19 coronavirus disease testing as demanded by the continuing pandemic.

Molecular epidemiology of Mycobacterium bovis in central parts of Malawi.

Bovine tuberculosis (bTB) is a neglected disease that affects cattle and humans. The burden of bTB is higher in developing countries as compared to industrialized countries. The reasons behind this discrepancy include the fact that bTB control measures, such as testing and slaughter of infected cattle and pasteurization of milk, are not usually practised in developing countries largely because of their high cost. To improve our understanding of bTB in developing countries, molecular typing studies are essential, in particular in terms of transmission dynamics, infection sources and knowledge of circulating strains of the principal causative agent, Mycobacterium bovis. In this study, we applied a suite of molecular typing techniques encompassing deletion analysis, spoligotyping and MIRU-VNTR to isolates recovered from samples collected during the routine post-mortem of cattle at the cold storage abattoir in Lilongwe, Malawi. Out of 63 isolates, 51 (81%) belonged to the European 1. M. bovis clonal complex. Spoligotyping identified 8 profiles, with SB0131 being the predominant type (56% of isolates). Spoligotypes SB0273 and SB0425 were identified in 14% and 13%, respectively, of the isolates. MIRU-VNTR showed a high discriminatory power of 0.959 and differentiated the 8 spoligotypes to 31 genotypes. The high diversity of M. bovis within the study area suggests the infection has been circulating in the area for a considerable period of time, likely facilitated by the lack of effective control measures. We also observed genetic similarities between isolates from Malawi (this study) to isolates described in previous studies in Zambia and Mozambique, suggesting transmission links in this region. The information provided by this study provides much needed evidence for the formulation of improved bTB control strategies.

Carriage Prevalence of Extended-Spectrum ß-Lactamase Producing Enterobacterales in Outpatients Attending Community Health Centers in Blantyre, Malawi.

Antimicrobial resistance due to extended-spectrum ß-lactamase (ESBL) production by Enterobacterales is a global health problem contributing to increased morbidity and mortality, particularly in resource-constrained countries. We aimed to determine the prevalence of extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) in community patients in Blantyre, Malawi. Clinical samples were collected from 300 patients and screened for ESBL-E using a CHROMagarTM ESBL medium. Confirmation of ESBL production was done by a combination disk test (CDT). The prevalence of community-acquired ESBL-E was 16.67% (50/300, 95% CI = 12.43-20.91%). The most common ESBL-E species isolated was Escherichia coli (66%). All ESBL-E isolates were resistant to Trimethoprim-Sulfamethoxazole except for 2% of E. coli. Besides this, all ESBL-E were susceptible to Imipenem and only 4% were resistant to Meropenem. No patients with a positive ESBL-E phenotype had a history of hospital admission in the last three months, and the carriage of ESBL-E was neither associated with the demographic nor the clinical characteristics of participants. Our findings reveal a low presence of ESBL-E phenotypes in community patients. The low prevalence of ESBL-E in the community settings of Blantyre can be maintained if strong infection and antimicrobial use-control strategies are implemented.

An international, interlaboratory ring trial confirms the feasibility of an open-source, extraction-less "direct" RT-qPCR method for reliable detection of SARS-CoV-2 RNA in clinical samples.

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is used worldwide to test and trace the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). "Extraction-less" or "direct" real time-reverse transcription polymerase chain reaction (RT-PCR) is an open-access qualitative method for SARS-CoV-2 detection from nasopharyngeal or oral pharyngeal samples with the potential to generate actionable data more quickly, at a lower cost, and with fewer experimental resources than full RT-qPCR. This study engaged 10 global testing sites, including laboratories currently experiencing testing limitations due to reagent or equipment shortages, in an international interlaboratory ring trial. Participating laboratories were provided a common protocol, common reagents, aliquots of identical pooled clinical samples, and purified nucleic acids and used their existing in-house equipment. We observed 100% concordance across laboratories in the correct identification of all positive and negative samples, with highly similar cycle threshold values. The test also performed well when applied to locally collected patient nasopharyngeal samples, provided the viral transport media did not contain charcoal or guanidine, both of which appeared to potently inhibit the RT-PCR reaction. Our results suggest that open-access, direct RT-PCR assays are a feasible option for more efficient COVID-19 coronavirus disease testing as demanded by the continuing pandemic.