Molecular epidemiology of bovine tuberculosis in Northern Ghana identifies several uncharacterized bovine spoligotypes and suggests possible zoonotic transmission.

OBJECTIVE: We conducted an abattoir-based cross-sectional study in the five administrative regions of Northern Ghana to determine the distribution of bovine tuberculosis (BTB) among slaughtered carcasses and identify the possibility of zoonotic transmission. METHODS: Direct smear microscopy was done on 438 tuberculosis-like lesions from selected cattle organs and cultured on Lowenstein-Jensen media. Acid-fast bacilli (AFB) isolates were confirmed as members of the Mycobacterium tuberculosis complex (MTBC) by PCR amplification of IS6110 and rpoß. Characterization and assignment into MTBC lineage and sub-lineage were done by spoligotyping, with the aid of the SITVIT2, miruvntrplus and mbovis.org databases. Spoligotype data was compared to that of clinical M. bovis isolates from the same regions to identify similarities. RESULTS: A total of 319/438 (72.8%) lesion homogenates were smear positive out of which, 84.6% (270/319) had microscopic grade of at least 1+ for AFB. Two hundred and sixty-five samples (265/438; 60.5%) were culture positive, of which 212 (80.0%) were MTBC. Approximately 16.7% (34/203) of the isolates with correctly defined spoligotypes were negative for IS6110 PCR but were confirmed by rpoß. Spoligotyping characterized 203 isolates as M. bovis (198, 97.5%), M. caprae (3, 1.5%), M. tuberculosis (Mtbss) lineage (L) 4 Cameroon sub-lineage, (1, 0.5%), and M. africanum (Maf) L6 (1, 0.5%). A total of 53 unique spoligotype patterns were identified across the five administrative regions (33 and 28 were identified as orphan respectively by the SITVIT2 and mbovis.org databases), with the most dominant spoligotype being SIT1037/ SB0944 (77/203, 37.93%). Analysis of the bovine and human M. bovis isolates showed 75% (3/4) human M. bovis isolates sharing the same spoligotype pattern with the bovine isolates. CONCLUSION: Our study identified that approximately 29% of M. bovis strains causing BTB in Northern Ghana are caused by uncharacterized spoligotypes. Our findings suggest possible zoonotic transmission and highlight the need for BTB disease control in Northern Ghana.

Diagnosis of tuberculosis among COVID-19 suspected cases in Ghana.

BACKGROUND: Tuberculosis (TB) and COVID-19 pandemics are both diseases of public health threat globally. Both diseases are caused by pathogens that infect mainly the respiratory system, and are involved in airborne transmission; they also share some clinical signs and symptoms. We, therefore, took advantage of collected sputum samples at the early stage of COVID-19 outbreak in Ghana to conduct differential diagnoses of long-standing endemic respiratory illness, particularly tuberculosis. METHODOLOGY: Sputum samples collected through the enhanced national surveys from suspected COVID-19 patients and contact tracing cases were analyzed for TB. The sputum samples were processed using Cepheid's GeneXpert MTB/RIF assay in pools of 4 samples to determine the presence of Mycobacterium tuberculosis complex. Positive pools were then decoupled and analyzed individually. Details of positive TB samples were forwarded to the NTP for appropriate case management. RESULTS: Seven-hundred and seventy-four sputum samples were analyzed for Mycobacterium tuberculosis in both suspected COVID-19 cases (679/774, 87.7%) and their contacts (95/774, 12.3%). A total of 111 (14.3%) were diagnosed with SARS CoV-2 infection and six (0.8%) out of the 774 individuals tested positive for pulmonary tuberculosis: five (83.3%) males and one female (16.7%). Drug susceptibility analysis identified 1 (16.7%) rifampicin-resistant tuberculosis case. Out of the six TB positive cases, 2 (33.3%) tested positive for COVID-19 indicating a coinfection. Stratifying by demography, three out of the six (50%) were from the Ayawaso West District. All positive cases received appropriate treatment at the respective sub-district according to the national guidelines. CONCLUSION: Our findings highlight the need for differential diagnosis among COVID-19 suspected cases and regular active TB surveillance in TB endemic settings.