RESUMO
Background: Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), is one of the top infectious killer diseases in the world. The emergence of drug-resistant MTB strains has thrown challenges in controlling TB worldwide. This study investigated the prevalence of drug-resistant tuberculosis in the states of Nigeria and the risk factors that can increase the incidence of tuberculosis. Methods: The study is a cross-sectional epidemiological research carried out in the six senatorial districts of Ekiti and Ondo states, Nigeria, between February 2019 and January 2020. A structured questionnaire was administered to 1203 respondents for socio-demographic information, and sputum samples were collected from them for TB investigation. GeneXpert technique was used to diagnose TB from the sputum samples, followed by bacterial isolation using Löweinstein-Jensen medium and antibiotic susceptibility testing. Results: Prevalence of TB in the two states combined was 15 â%; with 13.8 â% for Ekiti state and 16.1 â% for Ondo State. The distribution of TB in the senatorial districts was such that: Ondo South â> âEkiti Central â> âEkiti South â> âOndo North â> âEkiti North â> âOndo Central. The risk factors identified for TB prevalence in two states were gender, male â> âfemale (OR â= â0.548, p â= â0.004); overcrowding (OR â= â0.733, p â= â0.026); room size (OR â= â0.580, p â= â0.002); smoking (OR â= â0.682, p â= â0.019) and dry and dusty season (OR â= â0.468, p â= â0.005). The prevalence of MDR-TB in Ekiti and Ondo States were 1.2 â% and 1.3 â% respectively. The identified risk factors for MDR were education (OR â= â0.739, p â= â0.017), age (OR â= â0.846, p â= â0.048), religion (OR â= â1.95, p â= â0.0003), family income (OR â= â1.76, p â= â0.008), previous TB treatment (OR â= â3.64, p â= â0.004), smoking (OR â= â1.33, p â= â0.035) and HIV status (OR â= â1.85, p â= â0.006). Rifampicin monoresistant was reported in 6.7 â% of the rifampicin-resistant strains, while 93.3 â% were rifampicin polyresistant strains. Two (13.3 â%) of the MDR-TB strains were resistant to all the 3 first-line antimycobacterial agents. All the Rifampicin-resistant TB strains were susceptible to the aminoglycosides (Amikacin, Capreomycin and Kanamycin), also with high susceptibility to the fluoroquinilones: Moxifloxacin (100 â%) and Levofloxacin (86.7 â%). Sixteen (94.1 â%) of the 17 Rifampicin-susceptible strains were susceptible to all the eight antibiotics tested, while one (5.9 â%) was susceptible to Rifampicin and Isoniazid but resistant to the rest antibiotics. Conclusion: The study showed that there is high prevalence of TB and MDR-TB in Ekiti and Ondo States Nigeria, hence, to meet the SDG Target 3.3 of ending TB epidemic by 2030, culturing and antibiotic susceptibility testing should be carried out on every TB-positive sputum and the patients treated accordingly.
RESUMO
BACKGROUND: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate management requires baseline drug-resistance prevalence data. In West Africa, due to a poor laboratory infrastructure and inadequate capacity, such data are scarce. Therefore, the true extent of drug-resistant TB was hitherto undetermined. In 2008, a new research network, the West African Network of Excellence for Tuberculosis, AIDS and Malaria (WANETAM), was founded, comprising nine study sites from eight West African countries (Burkina Faso, The Gambia, Ghana, Guinea-Bissau, Mali, Nigeria, Senegal and Togo). The goal was to establish Good Clinical Laboratory Practice (GCLP) principles and build capacity in standardised smear microscopy and mycobacterial culture across partnering laboratories to generate the first comprehensive West African drug-resistance data. METHODS: Following GCLP and laboratory training sessions, TB isolates were collected at sentinel referral sites between 2009-2013 and tested for first- and second-line drug resistance. RESULTS: From the analysis of 974 isolates, an unexpectedly high prevalence of multi-drug-resistant (MDR) strains was found in new (6 %) and retreatment patients (35 %) across all sentinel sites, with the highest prevalence amongst retreatment patients in Bamako, Mali (59 %) and the two Nigerian sites in Ibadan and Lagos (39 % and 66 %). In Lagos, MDR is already spreading actively amongst 32 % of new patients. Pre-extensively drug-resistant (pre-XDR) isolates are present in all sites, with Ghana showing the highest proportion (35 % of MDR). In Ghana and Togo, pre-XDR isolates are circulating amongst new patients. CONCLUSIONS: West African drug-resistance prevalence poses a previously underestimated, yet serious public health threat, and our estimates obtained differ significantly from previous World Health Organisation (WHO) estimates. Therefore, our data are reshaping current concepts and are essential in informing WHO and public health strategists to implement urgently needed surveillance and control interventions in West Africa.
