Prevalence and Incidence of Smear-Positive Pulmonary Tuberculosis in the Hetosa District of Arsi Zone, Oromia Regional State of Central Ethiopia

Abstract

BackgroundThe real burden of smear-positive (PTB+) and bacteriologically confirmed tuberculosis (BCTB) in Ethiopia is not known. Thus, the aim of this community-based study was to measure the prevalence and incidence of tuberculosis in the Hetosa District of Oromia Region, Ethiopia.MethodsFirst, a population-based cross-sectional survey was conducted on a total of 33,073 individuals aged ≥ 15 years to determine the prevalence of PTB+ and BCTB cases. Then, in order to determine the incidence, a prospective follow-up was carried out on 32,800 individuals found to be either free from symptoms suggestive of TB (SSTB) during the baseline survey or had symptoms suggestive of TB but yielded negative bacteriological examination results. We identified 1,041 presumptive TB cases at the baseline survey, and 1,468 in the follow-up study. Each participants with cough of more than two weeks were provided spot and morning sputum samples for acid-fast bacilli sputum microscopy and culture.ResultsAt the baseline survey, 43 BCTB cases were identified. Thirty six of these were both smear- and culture-positive while seven were only culture-positive. In the follow-up study, however, 76 BCTB cases were diagnosed and 70 of these were found to be both smear- and culture-positive while six were culture-positive only. The adjusted prevalence of PTB+ and BCTB in the study area was 109 and 132/100,000 persons, respectively. Moreover, the incidences of PTB+ and BCTB were 214 and 232/100,000 persons per year (py), respectively. The ratio of the passive to active case finding was 1:0.96 (45/43). For every TB case identified through the existing passive case diagnosis, there was an almost equal number (0.96) of undiagnosed infectious TB cases in the community. A family history of TB contact was independently associated with a high risk of TB (TB prevalence, AOR, 13; 95% CI: 6.55–15.33) and (TB incidence, aIRR 4.11, 95% CI: 2.18–7.77).Conclusions and recommendationsThe prevalence and incidence of smear-positive and bacteriologically confirmed TB cases were high in the study area. For every case of smear-positive TB receiving treatment, there was an almost equal (0.96) number of undetected infectious bacteriologically confirmed TB case in the community. The high proportion of undetected infectious TB cases in the community could possibly be due to the sub-optimal performance of Directly Observed Treatment Short-course (DOTS) in detecting 70% of infectious TB cases, as well as attaining a cure rate of 85% in the study area. Family history of TB contact has substantaially increased the risk of developing the disease, and there is a need to improve ways of identifying TB cases and intensify mechanisms of tracing contacts among household members of PTB+ cases.

<p>Incidence and Predictors of Tuberculosis among Adult Diabetic Patients, Debre Markos Referral Hospital, Northwest Ethiopia, 2018: A Retrospective Cohort Study</p>

“…16 This might be due to differences in population and study layout (a prospective study was conducted on patients with type 2 DM) in north India, which had relatively decent insulin secretion and glycemic control that prevented the development of complications and coinfections compared to type 1 DM. Conversely, our finding is much lower than the TB incidence reported in Australia (5.8 per 100 PYs) and Ethiopia (Black Lion [ 3.8 per 100PYs] 17 and Dessie [6.2 per 100PYs] referral hospitals 18 ). In the same way, these variations among studies could be explained in part by differences in sample size, study settings, followup periods, and sociodemographic characteristics of study participants.…”

“…Accordingly, patients with a history of TB were 12 times as likely to develop TB than their counter parts (incidence-rate ratio 12, (95% CI 3-39); P=0.01), which is consistent with a study conducted in Australia 20 and studies in Ethiopia. 17,18,22 In addition, our study demonstrated that patients with BMI ≥18.5 kg/m 2 were at higher risk of TB than their counterparts (BMI <18.5 kg/m 2 , incidence-rate ratio 0.34, 95% CI 0.14-0.80; P=0.03), which aligns with previous studies conducted in southeastern Amhara, 26 Ethiopia (systematic review), 22 Egypt, 27 the US, 23,28 and China (adjusted HR 0.89, 95% CI 0.76-1.03). 25 Conversely, this study's findings contradict those of the study conducted in Ethiopia at Black Lion hospital.…”

Population-based screening for pulmonary tuberculosis utilizing community health workers in Ethiopia

“…The overall prevalence of laboratory-confirmed TB was 139 per 100 000 population, much lower than the national prevalence of 277 per 100 000 population (95% CI 208-347) (Kebede et al, 2014). The prevalence of smearpositive pulmonary TB was also lower than in several previous studies in Ethiopia, including the national prevalence survey (Kebede et al, 2014;Berhe et al, 2013;Hamusse et al, 2017;Shargie et al, 2006b;Yimer et al, 2009;Tadesse et al, 2011), but higher than a report from southwest Ethiopia (Deribew et al, 2012). Direct comparison is difficult because of differences in study methodology, population, and time.…”

“…The prevalence of smear-positive pulmonary TB was 108 per 100 000 per population according to a national populationbased TB survey conducted from October 2010 to June 2011, in which the vast majority of those identified were newly diagnosed cases that had not been captured by the control programme and most (55%) were among the younger age groups (15-34 years) (Kebede et al, 2014). Additional studies across various rural settings in Ethiopia have found a range of smear-positive pulmonary TB prevalence rates (from 30 to 174 per 100 000 population) suggesting that disease epidemiology varies across different geographical locations of the country (Berhe et al, 2013;Hamusse et al, 2017;Shargie et al, 2006b;Deribew et al, 2012;Yimer et al, 2009;Tadesse et al, 2011).…”

Tuberculosis Control Program in Sistan: An Eligible Model of A Tropical Area: Environmental and Epidemiological Reasons for Tuberculosis Resistance

“…This could be one of the reasons of TCPS progress. The access of TB care providers to international TB programs in their local language could remove extra cost in the fields of trial and error and planning alternative programs [28]. The TCPS screened whole Sistan area except Zabol city (the biggest city of this area) and it could be one of TB spread causes.…”