Epidemiology of Tuberculosis in an Urban Slum of Dhaka City, Bangladesh

Abstract

BackgroundThe objectives of this study were to assess the tuberculosis (TB) burden and to provide an insight into the type of circulating M. tuberculosis species in urban slums of Bangladesh. We also aimed to test the feasibility of a larger transmission study in this setting.MethodsThis cross-sectional study was conducted in an urban slum of Dhaka city. The household members were actively screened to assess the presence of TB-related signs and symptoms; cough ≥3 weeks and body mass index (BMI) <17 kg/m2. Sputum specimens from suspects were collected for acid fast bacilli (AFB) microscopy, culture and drug susceptibility testing. Genotyping of M. tuberculosis was done using spoligotyping and variable number tandem repeats of mycobacterial interspersed repetitive units typing.ResultsAmong 9,877 adult screened for pulmonary TB (PTB), 25 were positive for AFB on microscopy and/or culture and the prevalence of new PTB cases was estimated to be 253/100,000. Only one child TB case was diagnosed among 5,147 child screened. Out of 26 cases, 21(81%) had cough for several duration and 5(19%) did not present with cough at the time of screening. One multidrug resistant case was found. Fifty two percent of all TB cases had BMI <17 kg/m2 (p = <0.001). Among the 20 analyzed isolates, 13 different spoligotype patterns were identified in which 5 clusters contained 12 strains and 8 strains had unique pattern.ConclusionsThe study revealed high prevalence of TB in urban slums. Screening using low BMI can be beneficial among risk group population. It is important to conduct larger study to validate clinical variables like cough <3 weeks and low BMI to define TB suspect and also to investigate the transmission of TB in slum settings.

Reaching the underserved: Active tuberculosis case finding in urban slums in southeastern Nigeria

“…Although targeted screening of GOPD attendees accounted for substantial yields of TB cases, the intervention that appeared to be most effective based on the NNS was screening of people living with HIV/AIDS (PLWHIV), while the least effective was the screening of contacts of TB patients. This finding was consistent with findings from Rwanda, Ethiopia, Brazil and Peru where continuous screening of PLWHIV at HIV clinics was consistently found to have substantial yields from TB screening projects [11,14,23]. This study also showed that more than a quarter of the HIVinfected individuals tested for TB had TB, reinforcing the need to prioritize and promote early case finding strategies among PLWHIV.…”

“…This suggests that there is a likelihood of a high community transmission of TB in the population studied. The underlying factors promoting this transmission are likely due to overcrowding, poor housing and poor living conditions [12][13][14][15]. Overall, the yield of TB in this study was higher than in similar studies conducted elsewhere, i.e., 3.5% in Uganda [12], 0.2% in Cambodia [22] and 0.3% in Bangladesh [14].…”

“…The underlying factors promoting this transmission are likely due to overcrowding, poor housing and poor living conditions [12][13][14][15]. Overall, the yield of TB in this study was higher than in similar studies conducted elsewhere, i.e., 3.5% in Uganda [12], 0.2% in Cambodia [22] and 0.3% in Bangladesh [14]. The high yield of TB observed is an indicator of high underlying TB and HIV prevalence in urban slum settings of Nigeria and agrees with the findings of the recent TB prevalence survey in the country which showed that the majority of TB cases (most being smear-positive) in the community are not notified to the NTP [5].…”

“…The WHO recommends ACF strategies to be conducted among targeted high-risk groups, such as healthcare workers, HIV-positive individuals, miners, urban slum dwellers, diabetic patients, smokers, prisoners, immigrants and contacts of TB patients [11,12,14]. Studies that explored ACF in detecting TB cases in a high-risk population of urban slum dwellers who are poor, marginalized and exposed to poor environmental conditions (overcrowding, poor housing and poor living conditions) are crucial for TB control programs in resource-poor settings [12][13][14][15].…”

Sex Differences in Tuberculosis Burden and Notifications in Low- and Middle-Income Countries: A Systematic Review and Meta-analysis

“…The prevalence of bacteriologically positive TB was reported by sex in 56 surveys with 2.2 million participants in 24 countries [29,30,32,33,35,36,38–44,47–51,53,55,56,58–60,65–67,69–74,82,84,85,87,89–94,97,101,102,104,105,107,110–112]. Forty surveys with 1.7 million participants in 22 countries reported the prevalence of smear-positive TB by sex [35,40,43,44,48–51,53,55,56,58–60,65–67,69–71,73,74,85,87,89,90,92,94,97,101,102,105,107,110,111].…”