Mycobacterial Etiology of Pulmonary Tuberculosis and Association with HIV Infection and Multidrug Resistance in Northern Nigeria

Prevalence and Retrospective Insight on Tuberculosis in Human Patients in Cross River State, Nigeria; One Health Approach to its Control

Tuberculosis (TB) is a major zoonotic disease of public health importance worldwide. Its burden is more in developing countries due to inadequate surveillance, co-infection with HIV/AIDS and poor social amenities; hence consumption of unpasteurized milk, contaminated meat and inhalation of infected droplets from animals or patients with active TB are the major risk practices. A survey was conducted on TB prevalence from 2013 to 2014 while patients records from TB and Leprosy units of hospitals in the three Agricultural zones (Ogoja, Ikom and Calabar) of Cross River State, Nigeria were assessed from 2000 to 2010. Out of 1,170 sampled patients, 8 (0.7%) were positive, of which 6 and 2 isolates were identified as M. tuberculosis and M. bovis, respectively. Out of 52,558 studied patients files, 235 (0.4%) were positive with varied annual prevalence; the highest (1.0%) and lowest (0.2%) in 2009 and 2011, respectively. The prevalence was higher in dry (0.9% and 0.5%) than the rainy season (0.5% and 0.4%), in females (0.9% and 0.5%) than the males (0.4% and 0.4%) in the survey and retrospective studies, respectively. The age distribution of TB among the patients were; (0% and 0.3%), (0.4% and 0.4%), (0.7% and 0.4%) and (1.5% and 0.7%) for those (≤ 18), (19-40), (41-60) and (> 60) yrs old in the survey and retrospective study, respectively. TB is prevalent in human patients in Cross River State hence, the need for sustainable campaign, continuous surveillance and private/ public health partnership in accurate and early diagnosis, treatment and one health approach to its control.

Tuberculosis treatment outcomes of diabetic and non-diabetic TB/HIV co-infected patients: A nationwide observational study in Brazil

Background

Tuberculosis (TB) is a worldwide public health problem, especially in countries that also report high numbers of people living with HIV (PLWH) and/or diabetes mellitus (DM). However, the unique features of persons with TB-HIV-DM are incompletely understood. This study compared anti-TB treatment (ATT) outcomes of diabetic and non-diabetic TB/HIV co-infected patients.

Methods

A nationwide retrospective observational investigation was performed with data from the Brazilian Tuberculosis Database System among patients reported to have TB-HIV co-infection between 2014 and 2019. This database includes all reported TB cases in Brazil. Exploratory and association analyses compared TB treatment outcomes in DM and non-DM patients. Unfavorable outcomes were defined as death, treatment failure, loss to follow-up or recurrence. Multivariable stepwise logistic regressions were used to identify the variables associated with unfavorable ATT outcomes in the TB-HIV population.

Results

Of the 31,070 TB-HIV patients analyzed, 999 (3.2%) reported having DM. However, in these TB-HIV patients, DM was not associated with any unfavorable treatment outcome [adjusted Odds Ratio (aOR): 0.97, 95% CI: 0.83-1.12, p = 0.781]. Furthermore, DM was also not associated with any specific type of unfavorable outcome in this study. In both the TB-HIV group and the TB-HIV-DM subpopulation, use of alcohol, illicit drugs and tobacco, as well as non-white ethnicity and prior TB were all characteristics more frequently observed in persons who experienced an unfavorable ATT outcome.

Conclusion

DM is not associated with unfavorable TB treatment outcomes in persons with TB-HIV, including death, treatment failure, recurrence and loss to follow up. However, consumption habits, non-white ethnicity and prior TB are all more frequently detected in those with unfavorable outcomes in both TB-HIV and TB-HIV-DM patients.

INCIDENCE OF RIFAMPICIN-RESISTANCE PRESUMPTIVE M. TUBERCULOSIS CASES AMONG OUTPATIENTS IN KEBBI STATE, NIGERIA

Background:

The present study determined the incidence of rifampicin resistance M. tuberculosis among outpatients at the General Hospital Yauri, Kebbi State, Nigeria.

Materials and Methods:

The study is a cross-sectional study conducted from February 2018 to October 2019. Sociodemographic data were collected from hospital registration books. Rifampicin resistance M. tuberculosis was detected using GeneXpert Model GX-IV following manufacturers’ instruction. Descriptive statistics and logistic regression were computed using SPSS version 20. The results were presented as odds ratios with associated 95% confidence intervals, and P-value at 0.05.

Result:

Of the 837 samples, 65.8% (551/837) were males, and 34.2% (286/837) females, 11.4% (95/837) HIV-seropositive. M. tuberculosis was detected in 15.5% (130/837), of which 116/130 (89.23%) were males and 14/130 (10.77%) females. M. tuberculosis-HIV coinfection was detected in 9.47% (9/95) of HIV positive. Rifampicin resistance was observed in 1.3% (11/837), 7.7% (10/130) in M. tuberculosis patients and 1.05% (1/94) in HIV seropositive. In logistic regression, the odds ratio for having a rifampicin-resistant M. tuberculosis was 0.49 (0.15-1.54) for > 30 years; taking <30 years as the reference value, 1.02 (1.00-1.03) for male; taking female as the reference value, and 0.78 (0.09-6.15) for HIV positive, taking negative as the reference value.

Conclusion:

This study reported the current incidence rate of rifampicin-resistant M. tuberculosis at the General Hospital Yelwa Yauri, Kebbi State, Nigeria, among presumptive TB patients. Patients diagnosed with rifampicin-resistant M. tuberculosis were predominantly male adults. Thus, frequent screening is vital for surveillance and reduces the risk of transmission and spread of M. tuberculosis infections.

Rifampicin-Resistant Mycobacterium tuberculosis Among Patients with Presumptive Tuberculosis in Addis Ababa, Ethiopia

Background

Drug-resistant tuberculosis remains a major public health threat complicating tuberculosis control programs globally. Data on rifampicin resistance (RR), which is a surrogate marker for multidrug resistance, are limited among Ethiopian tuberculosis patients. This study aimed to determine the magnitude of rifampicin-resistant Mycobacterium tuberculosis (RR-MTB) among presumptive tuberculosis patients attending St. Peter Tuberculosis Specialized Hospital, Addis Ababa, Ethiopia.

Patients and Methods

A retrospective cross-sectional study was conducted at St. Peter Tuberculosis Specialized Hospital from January 2016 to December 2018. After checking completeness of the necessary information, data of tuberculosis-presumptive cases who underwent Gene Xpert^® testing were collected from medical records using a data-extraction format prepared for this study purpose. Data were double entered and analyzed using SPSS version 20 statistical software.

Results

A total of 12,685 presumptive tuberculosis patients were included; of whom 54.5% were males and the mean age of the study participants was 40.3±18.7 years. Mycobacterium tuberculosis (MTB) was detected in 1714 participants (13.5%). Of these MTB cases, 169 cases (9.8%) were confirmed to have RR-MTB. Prevalence of MTB was relatively higher among males (15.1%, P=0.78); whereas RR-MTB was higher among females (10.3%, P=0.81). The incidence of MTB and RR-MTB was significantly associated with treatment history (P=0.042 and P=0.025), respectively. HIV infection has significantly associated with incidence of RR-MTB (P=0.032), but not with MTB (P˃0.05). Prevalence of MTB and RR-MTB had a declining trend through time, being 16.7% and 12.9%, 12.8% and 9.1%, and 12.2% and 7.9% in 2016, 2017 and 2018, respectively.

Conclusion

This study showed a decreasing trend of both MTB and RR-MTB from 2016 to 2018 in an MTB, MDR-MTB, and TB/HIV co-infection high-burden setting, Addis Ababa, Ethiopia. Occurrence of MTB and RR-MTB was associated with treatment history. Therefore, improvement in treatment adherence of identified cases would be helpful to prevent emergence or re-emergence of MTB and RR-MTB cases.

Genetic characterization of Mycobacterium tuberculosis complex isolates circulating in Abuja, Nigeria

Objective

Nigeria ranks fourth among the high tuberculosis (TB) burden countries. This study describes the prevalence of drug resistance and the genetic diversity of Mycobacterium tuberculosis in Abuja’s Federal Capital Territory.

Materials and methods

Two hundred and seventy-eight consecutive sputum samples were collected from adults with presumptive TB during 2013–2014. DNA was extracted from Löwenstein–Jensen cultures and analyzed for the identification of nontuberculous mycobacteria species, detection of drug resistance with line probe assays, and high-throughput spacer oligonucleotide typing (spoligotyping) using microbead-based hybridization.

Results

Two hundred and two cultures were positive for M. tuberculosis complex, 24 negative, 38 contaminated, and 15 positive for nontuberculous mycobacteria. Five (2.5%) M. tuberculosis complex isolates were resistant to rifampicin (RIF) and isoniazid (multidrug resistant), nine (4.5%) to RIF alone, and 15 (7.4%) to isoniazid alone; two RIF-resistant isolates were also resistant to fluoroquinolones and ethambutol, and one multidrug resistant isolate was also resistant to ethambutol. Among the 180 isolates with spoligotyping results, 164 (91.1%) were classified as lineage 4 (Euro-American), 13 (7.2%) as lineage 5 (West African 1), two (1.1%) as lineage 2 (East Asia), and one (0.6%) as lineage 6 (West African 2). One hundred and fifty-six (86.7%) isolates were grouped in 17 clusters (2–108 isolates/cluster), of which 108 (60.0%) were grouped as L4.6.2/Cameroon (spoligotype international type 61).

Conclusion

The description of drug resistance prevalence and genetic diversity of M. tuberculosis in this study may be useful for improving TB control in Nigeria.

Demography and the dual epidemics of tuberculosis and HIV: Analysis of cross-sectional data from Sub-Saharan Africa

Background

Convergence of tuberculosis (TB) and HIV epidemics is associated with higher morbidity and mortality risks and understanding their distribution across key demographic factors is essential for prevention and control. This analysis examines the prevalence of TB, HIV and TB-HIV coinfection across age and gender in patients with presumptive TB seeking care at the National TB and Leprosy Training Center in Nigeria.

Methods

Samples from 1603 presumptive pulmonary TB cases who provided informed consent were evaluated with a sequential testing algorithm that included a smear microscopy, cultures in liquid and broth media and then genotyping by Hain line probe assays. HIV was serially tested with two HIV rapid assays and retested with a third assay in non-conclusive samples.

Results

Twenty-three percent (375/1603) had confirmed pulmonary TB infection, 23.6% (378/1603) were positive for HIV infection and 26.9% (101/375) of the confirmed TB cases were HIV co-infected. Males had a higher prevalence of TB: 27.6% vs. 18.0%, p < .0001; and a lower prevalence of HIV: 19.0% vs. 29.6%, p < .0001. In the age range of 25–29 years, males were twice as likely to have TB (OR = 2.2; 95% confidence interval [CI]: 1.3–3.9, p = 0.0032) while females were five times more likely to have HIV (OR = 4.8; 95% CI: 2.6–8.9, p < .0001). Persons with TB-HIV coinfection were more likely to be young, female and less likely to be married.

Conclusion

Younger females with a high burden of HIV may be under-diagnosed and under-reported for TB in Nigeria. Community programs for intensified and early detection of TB and HIV targeting younger females are needed in this setting.

Xpert MTB/RIF assay for the diagnosis of Mycobacterium tuberculosis and Rifampicin resistance in high Human Immunodeficiency Virus setting in Gambella regional state, southwest Ethiopia

Background

The introduction of a new and rapid molecular diagnostic for tuberculosis (TB) and rifampicin resistance (RIF) in the national TB program has improved the diagnosis of TB by shortening the turnaround time and detecting the presence of RIF resistance in high TB and human immunodeficiency virus (HIV) settings such as Ethiopia. However, the implementation of this new diagnostic tool for the diagnosis of M. tuberculosis (MTB) and rifampicin (RIF) resistance in clinical setting is limited known in the country. Hence, this study intended to describe the program of GeneXpert MTB/RIF in the diagnosis of TB and RIF in high HIV setting in Gambella Regional State, Southwest Ethiopia.

Method

Institutional based retrospective study was conducted among presumptive TB patients diagnosed with GeneXpert assay in the last three years (2015–2017) in Gambella Hospital from May 1–30, 2017. The data were collected from GeneXpert registration book using standard data extraction sheet. The data were entered and cleared using EPI data 3.1 and then, exported and analyzed using SPSS version 20.0 statistical software package.

Result

Of the 995 presumptive TB patients who received the GeneXpert test in the last three years, 20.0% (95% CI: 17.4–22.7) of them had proven MTB detection while 4.9% (95% CI: 2.2–8.1) had RIF resistance. The prevalence of RIF resistance was 2.3% and 14.3% among the new and retreated cases respectively. There was also a 35.5% TB/HIV co-infections. The odd of MTB detection was higher among 15–29 [AOR 2.17 (95% CI: 1.25- 3.76)] and 30–44 [AOR 2.35 (95% CI: 1.36–4.07)] year old participants. The figure was however significantly lower among female [AOR 0.64 (95% CI: 0.45–0.91)] and unknown HIV status [AOR 0.38(95% CI: 0.24–0.61)] participants of the study. In addition, the odd of RIF resistance was significantly low among HIV unknown case [AOR 0.14 (95% CI: 0.02–0.96)]. It was also learnt that there was progressively decline of invalid or error Xpert result from 4.7% to 2.0% in the course of the study period (X², 25.54; P = 0.001).

Conclusion

The study confirms the high prevalence of TB, RIF resistance and TB/HIV co-infection among the study participants. Age, sex, and HIV status of the study participants were predictor factors for MTB detection while HIV status was associated with RIF resistance. Therefore, the results of the study indicate that there is the need for collaborative and intensified prevention of TB and HIV in the study area. The ongoing supervision and mentoring to improve the performance of Xpert in the institution need to be promoted.

Trends in prevalence of multi drug resistant tuberculosis in sub-Saharan Africa: A systematic review and meta-analysis

Background

Multidrug resistant tuberculosis (MDR-TB), is an emerging public health problem in sub-Saharan Africa (SSA). This study aims to determine the trends in prevalence of MDR-TB among new TB cases in sub-Saharan Africa over two decades.

Methods

We searched electronic data bases and accessed all prevalence studies of MDR-TB within SSA between 2007 and 2017. We determined pooled prevalence estimates using random effects models and determined trends using meta-regression.

Results

Results: We identified 915 studies satisfying inclusion criteria. Cumulatively, studies reported on MDR-TB culture of 34,652 persons. The pooled prevalence of MDR-TB in new cases was 2.1% (95% CI; 1.7–2.5%). There was a non-significant decline in prevalence by 0.12% per year.

Conclusion

We found a low prevalence estimate of MDR-TB, and a slight temporal decline over the study period. There is a need for continuous MDR-TB surveillance among patients with TB.

Prevalence of drug-resistant tuberculosis in Nigeria: A systematic review and meta-analysis

Background

Drug-resistant tuberculosis (TB) undermines control efforts and its burden is poorly understood in resource-limited settings. We performed a systematic review and meta-analysis to provide an up-to-date summary of the extent of drug-resistant TB in Nigeria.

Methods

We searched PubMed, Scopus, Embase, HINARI, AJOL, the Cochrane library, Web of Science, and Google Scholar for reports published before January 31 2017, that included any resistance, mono-resistance or multidrug resistance to anti-TB drugs in Nigeria. Summary estimates were calculated using random effects models.

Results

We identified 34 anti-TB drug resistance surveys with 8002 adult TB patients consisting of 2982 new and 5020 previously-treated cases. The prevalence rate of any drug resistance among new TB cases was 32.0% (95% CI 24.0–40.0%; 734/2892) and among previously-treated cases, the rate was 53.0% (95% CI 35.0–71.0%; 1467/5020). Furthermore, multidrug resistance among new and previously-treated cases was 6.0% (95% CI 4.0–8.0%;161/2502)and 32.0% (95%CI 20.0–44.0; 357/949), respectively. There was significant heterogeneity between the studies (p<0.001, I² tests). The prevalence of drug-resistant TB varied according to methods of drug susceptibility testing and geographic region of Nigeria.

Conclusion

The burden of drug-resistant TB in Nigeria is high. We recommend that a national anti-TB drug resistance survey be carried out, and strategies for case detection and programmatic management of drug-resistant TB in Nigeria need to be strengthened.

Rifampicin-resistance pattern of Mycobacterium tuberculosis and associated factors among presumptive tuberculosis patients referred to Debre Markos Referral Hospital, Ethiopia: a cross-sectional study

BACKGROUND

Prevailing data on rifampicin-resistant M. tuberculosis is essential for early management of MDR-TB. Therefore, this study was conducted to determine the prevalence of rifampicin-resistant Mycobacterium tuberculosis and associated factors among presumptive TB cases in Debre Markos Referral Hospital, Ethiopia.

METHODS

A cross-sectional study was conducted from September 2014 to March 2015. Detection of M. tuberculosis and resistance to rifampicin was performed using Gene Xpert MTB/RIF assay. Data was collected using structured questionnaire by face to face interview. Logistic regression analysis was computed to determine the associated factors of rifampicin-resistant M. tuberculosis.

RESULTS

A total of 505 presumptive TB patients included in the study. The prevalence of M. tuberculosis confirmed cases was 117 (23.2%) (95% CI 19.7-27%). It was higher among males (27.9%) than females (17.9%) (AOR: 2.17; CI 1.35-3.49). Of the 117 M. tuberculosis confirmed cases, 12 (10.3%) (95% CI 6.0-17.1%) were resistant to rifampicin. Rifampicin-resistant M. tuberculosis was noticed in 7 previously treated TB patients (17.1%) and 5 treatment naive patients (6.7%) (AOR: 4.16; CI 1.04-16.63). The prevalence of rifampicin-resistant M. tuberculosis was 6 (9.8%) and 6 (11.3%) in pulmonary and extra-pulmonary infections, respectively. Of the 30, MTB/HIV co-infection, 3 (10%) were rifampicin-resistant M. tuberculosis.

CONCLUSION

Rifampicin-resistant M. tuberculosis is prevalent in both pulmonary and extra-pulmonary tuberculosis patients. Previous treatment with anti-TB drugs was significantly associated with rifampicin resistance. Therefore, the use of Gene Xpert should be scaled up across the country for rapid detection and management of drug resistant M. tuberculosis.

Cost-effectiveness of point-of-care digital chest-x-ray in HIV patients with pulmonary mycobacterial infections in Nigeria

Background

Chest-x-ray is routinely used in the diagnosis of smear negative tuberculosis (TB). This study assesses the incremental cost per true positive test of a point-of-care digital chest-x-ray, in the diagnosis of pulmonary mycobacterial infections among HIV patients with presumed tuberculosis undetected by smear microscopy.

Methods

Consecutive patients with clinical suspicion of pulmonary tuberculosis were serially tested for Human immunodeficiency virus (HIV), their sputum examined for Acid Fast Bacilli then cultured in broth and solid media. Cultures characterized as tuberculous (M.tb) and non-tuberculous (NTM) mycobacteria by Hain assays were used as gold standards. A chest-x-ray was classified as: (1) consistent for TB, (2) not consistent for TB and (3) no pathology.

Results

Of the 1391 suspected cases enrolled, complete data were available for 952 (68%): 753/952 (79%) had negative smear tests while 150/753 (20%) had cultures positive for TB. Of those, 82/150 (55%) had chest-x-ray signs consistent with TB and 29/82 (35%) were positive for HIV. Within the co-infected, 9/29 (31%) had NTM infections. Among all suspects, the cost per positive case detected using smear microscopy test was $52.84; the overall incremental cost per positive case using chest-x-ray in smear negatives was $23.42, and in smear negative, HIV positive patients the cost was $15.77.

Conclusion

Point-of-care chest-x-ray is a cost-effective diagnostic tool for smear negative HIV positive patients with pulmonary mycobacterial infection.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0675-0) contains supplementary material, which is available to authorized users.

Diagnostic accuracy of Xpert MTB/RIF for extrapulmonary tuberculosis specimens: establishing a laboratory testing algorithm for South Africa

South Africa implemented Xpert MTB/RIF as the initial diagnostic test for pulmonary tuberculosis (TB). Xpert MTB/RIF's accuracy for diagnosing extrapulmonary tuberculosis (EPTB) was investigated. EPTB specimens (n = 7,916) from hospitalized patients received over a 6-month period at a high-throughput TB referral laboratory in Johannesburg were investigated. Large-volume specimens were centrifuged, tissue biopsy specimens homogenized, and all specimens checked for growth of contaminating bacteria on blood agar. Contaminated samples received NALC-NaOH (N-acetyl-l-cysteine-sodium hydroxide) decontamination prior to liquid culture. Residual specimens (volumes > 1 ml) after inoculation of culture (n = 1,175) were tested using the Xpert MTB/RIF sputum protocol. Using culture as the reference, Xpert MTB/RIF's overall sensitivity was 59% (95% confidence interval [95% CI], 53% to 65%) and specificity was 92% (CI, 90% to 94%), with the highest sensitivities of 91% (95% CI, 78% to 97%) for pus, 80% (95% CI, 56% to 94%) for lymph node aspirates, and 51% (95% CI, 44% to 58%) for fluids (ascitic, 59%; pleural, 47%). A difference in sensitivities was noticed between specimens classified as having a thick (87% [95% CI, 76% to 94%]) versus clear (watery) (48% [95% CI, 36% to 61%]) appearance. This was unchanged with traces of blood (52% [95% CI, 44% to 60%]) or precentrifugation (57% [95% CI, 28% to 82%]) among clear specimens. Xpert MTB/RIF generated an additional 124 specimen results that were contaminated by Mycobacterial Growth Indicator Tubes (MGIT; 10.5%) and diagnosed rifampin (RIF) resistance earlier (9.6% [25/260]). Xpert MTB/RIF's performance on EPTB specimens provides very promising results and should be considered for incorporation into national TB guidelines. Xpert MTB/RIF is less affected by contaminating bacteria and reduces laboratory labor and diagnostic delay compared to traditional methods.