Genomic diversity and transmission dynamics of M. tuberculosis in Africa: a systematic review and meta-analysis.

BACKGROUND: Mycobacterium tuberculosis complex (MTBC) and its human host are the most competent organisms with co-evolutionary trajectory. This review determined the phylogeography, clinical phenotype-related genotype and transmission dynamics of MTBC in Africa.METHODS: Spoligotyping and mycobacterial interspersed repetitive units-variable number tandem repeats (MIRU-VNTR) based articles from Africa published in the English language were included. Articles were retrieved from PubMed and Scopus on 12 May 2018.RESULTS: In Africa, respectively 92% and 7% of tuberculosis (TB) cases were caused by M. tuberculosis and M. africanum. Among M. tuberculosis lineages (L), L4 was the predominant, at 67%, followed by L3/Central Asian (CAS; 10%). L7/ETH1 and L5/6/Maf were restricted to the Horn and Western Africa, respectively. L4.6/SIT37, H37Rv like, L4.1.2/Haarlem and H3-Ural were proportionally more frequent among tuberculous lymphadenitis (TBLN) than among pulmonary tuberculosis (PTB) cases. On 24-locus MIRU-VNTR, clustering rate was 31%; the secondary case rate from a single primary source case was 20%.CONCLUSION: Africa in general, and the east-west pole of Africa in particular, harboured a genetically diverse population of MTBC, with characteristics of geographic segregation. Both generalist and specialist genotypes are circulating in the region. L4 is dominant across the continent, while M. bovis is rarely detected as a cause for human TB. The clinical significance of genetic diversity of MTBC in the different geographic and population groups of Africa is not fully understood. Both person-to-person transmission and reactivation mode of TB is significant in Africa. Prevention and control strategies should therefore envisage these two scenarios.

Review of the prevalence and drug resistance of tuberculosis in prisons: a hidden epidemic.

SUMMARY The prison setting has been often cited as a possible reservoir of tuberculosis (TB) including multidrug-resistant (MDR)-TB. This is particularly true in low-income, high TB prevalence countries in Sub-Saharan Africa. A systemic literature review was done to assess the prevalence, drug resistance and risk factors for acquiring TB in the prison population. Our review indicated a high prevalence of TB in prisons which is reported to be 3- to 1000-fold higher than that found in the civilian population, indicating evidence and the need for public health policy formulation. In addition, high levels of MDR and extensively drug-resistant (XDR)-TB have been reported from prisons, which is a warning call to review prison TB control strategy. Multiple risk factors such as overcrowding, poor ventilation, malnutrition, human immunodeficiency virus (HIV), and others have fuelled the spread of TB in prisons. Furthermore, the impact extends beyond the prison walls; it affects the civilian population, because family visits, prison staff, and members of the judiciary system could be potential portals of exit for TB transmission. The health of prisoners is a neglected political and scientific issue. Within these background conditions, it is suggested that political leaders and scientific communities should work together and give special attention to the control of TB and MDR-TB in prisons. If not, TB in prisons will remain a neglected global problem and threatens national and international TB control programmes. Further researches are required on the prevalence and drug resistance of smear-negative TB in prisons. In addition, evidence of the circulating strains and transmission dynamics inside prisons is also warranted.

Effect of Ethiopian multiflora honey on fluconazole-resistant Candida species isolated from the oral cavity of AIDS patients.

This study aimed to determine the antifungal effect of Ethiopian multiflora honey against Candida species isolated from the oral cavity of AIDS patients. Oral rinses were obtained from 13 AIDS patients and cultured on CHROMagar plates at 37°C for 48 hours. Candida species were identified by microbiological and molecular techniques. The antifungal effect of the honey sample on Candida was investigated by an agar dilution technique. Susceptibility of the Candida species to fluconazole was tested following a semi-modified microdilution method. Growth of both fluconazole-susceptible and -resistant Candida species was inhibited with a minimum fungicidal concentration (MFC) of 35-40% (v/v) honey. The MFC of different Candida species was not significantly different (P > 0.05). From the total of 25 Candida isolates tested for susceptibility, 11 (44%), eight (32%) and six (24%) of the isolates were sensitive (minimum inhibitory concentrations [MICs] < 8 µg/mL), susceptible (dose-dependent: MICs 16-32 µg/mL) and resistant (MICs > 64 µg/mL) to fluconazole, respectively. Ethiopian multiflora honey has antifungal activity against fluconazole-resistant Candida species isolated from the oral cavity of AIDS patients. This supports the existing folkloric practice of using honey to treat oral lesions. Nevertheless, identification of the bioactive agents in honey, their clinical evaluation and pharmacological standardization are crucial.