|Year : 2016 | Volume
| Issue : 2 | Page : 205-210
Magnitude and treatment outcomes of pulmonary tuberculosis patients in a poor urban slum of Abia State, Nigeria
Chidubem L Ogbudebe1, Sam Izuogu2, Charity E Abu3
1 German Leprosy and TB Relief Association, Enugu State, Nigeria
2 National Tuberculosis and Leprosy Control Programme, Ministry of Health, Abia State, Nigeria
3 Family Health International (FHI360), Anambra State Office, Anambra, Nigeria
|Date of Web Publication||9-Feb-2017|
Chidubem L Ogbudebe
35 Hill View, Independence Layout, Enugu
Source of Support: None, Conflict of Interest: None
Objective/Background: Tuberculosis (TB) remains one of the deadliest infectious diseases worldwide, with a disproportionate number of those affected living in slum areas. We assessed the magnitude of pulmonary cases among tuberculosis patients in an urban slum in southeast Nigeria, their demographic and clinical characteristics and any associations with treatment outcomes.
Methods: A retrospective cohort study of patients registered under the National TB Programme (NTP) from 1 January to 31 December 2012 was carried out. Data were extracted from TB treatment cards and registers.
Results: Of 647 new TB patients registered, 555 (85.8%) were pulmonary TB (PTB) with a mean age of 34.5years, and a male/female ratio of 1.3. Among these, 468 (84.3%) were smear-positive, while 87 (15.7%) were smear-negative cases. Twenty-one (3.8%) were children younger than 15years old. TB/HIV co-infection rate was 16.9%; 57.4% received antiretroviral therapy (ART) and 88.3% received cotrimoxazole preventive therapy (CPT). Female patients were significantly younger compared to male patients (p = 0.003), had higher proportions of smear-negative TB (p = 0.001) and HIV-positive status (p ≤ 0.001). Treatment success rate was 88.5% among smear-positive patients and 79.3% among smear-negative patients. More patients with smear-negative TB were lost to follow up compared with smear-positive TB patients (p < 0.02). HIV co-infection was associated with unfavourable treatment outcomes (OR 0.2, CI 0.1–0.4, p ≤0.001). Among them, those who received ART had better outcomes.
Conclusions: The study revealed high proportion of PTB, mostly smear-positive TB with HIV-associated outcomes and underlines the need to ensure early TB diagnosis and improved access to HIV care for HIV co-infected patients in this setting.
Keywords: Epidemiology, Nigeria, Treatment outcome, Tuberculosis, Urban slum
|How to cite this article:|
Ogbudebe CL, Izuogu S, Abu CE. Magnitude and treatment outcomes of pulmonary tuberculosis patients in a poor urban slum of Abia State, Nigeria. Int J Mycobacteriol 2016;5:205-10
|How to cite this URL:|
Ogbudebe CL, Izuogu S, Abu CE. Magnitude and treatment outcomes of pulmonary tuberculosis patients in a poor urban slum of Abia State, Nigeria. Int J Mycobacteriol [serial online] 2016 [cited 2019 Jun 20];5:205-10. Available from: http://www.ijmyco.org/text.asp?2016/5/2/205/199931
| Introduction|| |
Nigeria remains one of the countries with the highest tuberculosis (TB) burden in the world. According to the 2014 Global TB Control Report, the burden of TB is estimated at 338 per 100,000 population in the form of incidence and 322 per 100,000 population in the form of prevalence . The National TB Programme (NTP) was established in 1991 and adopted the World Health Organization (WHO) recommended DOTS strategy in 1993. TB case-detection rate, which continues to show a rising trend, stagnated at 51% in 2012. The 2012 national survey of TB prevalence showed that only one out of every five active TB cases in the communities was notified by the NTP .
In many countries, disparities in TB incidence within populations have been described . In urban areas, TB occurs mainly among risk groups, such as slum populations who are predisposed to poor living and environmental conditions ,,. However, TB patients in urban slums are rarely evaluated by NTPs in sub-Saharan Africa despite the pervasiveness of urban slums in recent years . The accurate measure of the burden of TB in urban slums is difficult to obtain, mainly due to under-reporting and/or non-inclusion of sub-population data in national routine surveillance systems. In 2012, 5.7 million newly diagnosed cases of TB were notified by NTPs worldwide; 360,000 of whom were HIV positive . Approximately 37% were estimated to occur among slum populations. In countries with high TB burden, slum populations account for 45–50% of all TB cases ,. This proportion is, however, less in countries with a low TB burden.
In Nigeria, information on the burden of TB in slum populations is limited, especially in relation to epidemiological characteristics and their associations with treatment outcomes. Such information, however, would be valuable in contributing to robust measurement and understanding of the national burden of TB disease. The Nigerian national routine surveillance system commonly captures information on TB registration for all patient categories within the general population, however, such information is not available at sub-population levels including high-risk groups, such as slum populations. This study aims to assess the magnitude of pulmonary cases among tuberculosis patients in an urban slum in southeast Nigeria, their demographic and clinical characteristics and any associations with treatment outcomes.
| Materials and methods|| |
This was a retrospective cohort study involving a review of TB treatment cards and registers maintained under the NTP surveillance system in Aba, Abia State, Nigeria, from January 1, 2012 to December 31, 2012.
The study was conducted at a low-income densely populated urban slum (Aba) located in Abia State. Aba has a projected population of 619,583  and is regarded as the most densely populated urban slum in Nigeria  with a population density estimated at 49.78persons/hectare. It is comprised mostly of a heterogeneous group of people, dump-sites and displaced populations, majority of who are living in unstructured temporary settlements. TB services (diagnosis and treatment) are integrated within the public health system and are managed by the state ministry of health under the NTP. There are five public health centres in Aba. The state ministry of health also collaborates with six private health facilities located within the slum for the provision of TB services in the context of public–private partnership. All public and private health facilities providing TB services in Aba participated in the study.
Diagnosis and management of TB
Diagnosis and management of TB was based on the NTP guidelines . A person coughing for 2weeks or more with or without other clinical presentation was identified as pulmonary TB suspect and requested by a health worker to provide three sputum samples (spot, morning, and spot) for acid-fast bacilli microscopy. Pulmonary smear positive TB was defined as a positive sputum smear for AFB (acid-fast bacilli) confirmed with one or more positive smears. Pulmonary smear negative was defined by negative smear for AFB with radiological, clinical, and/or histological findings consistent with active TB followed by the decision by a clinician to treat with a full course of TB chemotherapy.
Anti-TB treatment was based on the use of directly observed treatment (DOT), short course chemotherapy for a duration of 8months (2months intensive phase and 6months continuation phase). During the intensive phase, treatment was given daily under the direct observation of a trained health worker or a trained treatment supporter. For the continuation phase, treatment was given monthly and self-administered. Both smear-positive and smear-negative TB patients were treated with the same standardised first-line antituberculosis regimen consisting of rifampicin (R), isoniazid (H), pyrazinamide (Z), and ethambutol (E) in accordance with the NTP guidelines. HIV counselling and testing was offered to all patients, and those who were found to be HIV positive were referred for HIV care and support—antiretroviral therapy (ART) and cotrimoxazole preventive therapy (CPT). Diagnosis and treatment details of TB patients were recorded in routine standard NTP TB treatment cards and registers.
All health facilities providing TB services within the slum area were visited by two trained researchers. Relevant data of all new TB patients registered from January 1, 2012 to December 31, 2012 were extracted from the NTP TB treatment cards and registers into a data-collection form designed for this study. Variables recorded included TB registration number, gender, age, HIV status, type of TB, treatment duration, and treatment outcome.
Data were double-entered into a Excel 2013 (Microsoft Corporation, Redmond, WA) database by two independent data operators, and validated for inconsistencies. In case of disparities, information on the original data-collection tool was verified. Data analyses were performed using the Statistical Package for Social Sciences (SPSS) version 20.0 (IBM Corp, Armonk, NY, USA). For the purpose of this analysis, treatment outcomes were categorised as favourable (cured and treatment completed) and unfavourable (lost to follow-up, died, treatment failure, and transferred out). Demographic and clinical characteristics were described in terms of frequencies and percentages. The chi-square test, odds ratios (OR) and 95% confidence intervals (95% CI) were used to compare groups as appropriate. Levels of significance were set at 5%.
This study was based on review of existing records without involving patient interaction, hence, informed consent was deemed not necessary. Ethical clearance was obtained from the Ethics Committee of the Abia State University Teaching Hospital, Abia State, Nigeria. Institutional approval was obtained from the state TB control programme.
| Results|| |
Of 647 new TB cases registered under the NTP from January 1, 2012 to December 31, 2012, 555 (85.8%) were pulmonary TB (PTB) cases with a mean age of 34.5years and male/female ratio of 1.3. Among these, 468 (84.3%) were smear-positive TB and 87 (15.7%) smear-negative TB cases ([Table 1]). There were 21 (3.8%) children aged 0–14years. The proportion of pulmonary TB cases was highest (29.2%) among the 25–34 year age group. TB/HIV co-infection rate was 16.9% (n = 94). Of these, 57.4% (n = 54) received ART and 88.3% (n = 83) received CPT.
|Table 1: Demographic and clinical characteristics of patients with new pulmonary TB registered in 2012 (n = 555).|
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[Table 2] shows the characteristics of patients registered and disaggregation by gender. Female patients were significantly younger compared to male patients (p = 0.003), had higher proportions of smear-negative TB (p = 0.001) and HIV-positive status (p ≤ 0.001).
|Table 2: Demographic and clinical characteristics of patients disaggregated by gender (n = 555).|
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Treatment outcomes of smear-positive PTB patients and smear-negative PTB patients registered are shown in [Table 3]. Of 468 smear-positive PTB patients evaluated, 88.5% (n = 414) successfully completed treatment, 26 (5.6) died, 18 (3.8) were lost to follow-up, 9 (1.9) failed treatment and 1 (0.2) was transferred out. Among 85 smear-negative PTB patients evaluated, 79.3% (n = 65) successfully completed treatment, 5 (5.7) died, and 13 (14.9) were lost to follow-up. There were more patients with smear-negative PTB who were lost to follow-up compared with smear-positive PTB (p < 0.02). In [Table 4], treatment outcomes were assessed in relation to demographic characteristics, sites of disease, HIV status, and ART use for HIV-positive patients. HIV co-infected patients had a higher risk of unfavourable outcomes than HIV-negative PTB patients during treatment (OR 0.2, CI 0.1–0.4, p ≤ 0.001). Among them, TB treatment outcomes were much better among those who received ART (p < 0.001).
|Table 3: Treatment outcomes of new pulmonary TB patients registered under the NTP in 2012.|
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|Table 4: Comparison of demographic and clinical characteristics and treatment outcomes of TB cases registered under the NTP in 2012.|
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| Discussion|| |
In this study of the magnitude, profile, and treatment outcomes among pulmonary TB patients in an urban slum, we found that more than 85% of all new TB cases registered were pulmonary TB, mostly smear-positive TB and over half were aged 25–44years. Female patients were significantly younger compared to male patients, had a higher proportion of smear-negative TB and HIV-positive status. Although treatment outcomes were better among smear-positive than smear-negative TB patients, HIV-positive status was associated with unfavourable outcomes.
The measured proportion of pulmonary smear-positive TB cases in the study population was high, almost 30% higher than the national average. This is in line with the findings described in previous studies in Bangladesh and India , but higher than the rate reported among chronic coughers in Uganda, which revealed a proportion of 55% . These large numbers of pulmonary smear-positive TB cases indicate the high concentration of TB and underlying transmission in the slum areas. In sub-Saharan Africa, the situation is further complicated by a HIV epidemic which is currently running at a median prevalence of 3.4%  in Nigeria. The Nigerian NTP implements the WHO recommended DOTS strategy and its policy guidelines rely heavily on passive case-finding and use of sputum smear microscopy and chest X-ray findings for diagnosis of TB. Additional strategies complementing facility-based interventions that will involve systematically identifying potentially infectious individuals with pulmonary TB in the communities and facilitate early entry into TB care are clearly needed.
The age-specific distribution of TB showed that TB was most common among the 25–44year age group. This finding is consistent with results of similar studies in some high TB burden countries, like Bangladesh, Kenya, and India ,,. In contrast, in Vietnam, China, and Cambodia, the age group most affected was 65years and older followed by the 45–54year age group . The reason for these differences is not clear, though it may be due to difference in the levels of economic and demographic transmission occurring in these populations. A male–female ratio of 1.3 appears a common finding in several other countries ,,. Furthermore, the age–gender distribution shows that there were larger proportion of females among the childhood TB cases. The difference in the gender distribution of TB may be due to the epidemiologic situation in the setting concerned. Previous studies have shown that cultural factors leading to differences in access to health services, behavioural, and biological mechanisms are key reasons for susceptibility differences between men and women .
Treatment outcomes were better among smear-positive than smear-negative patients. The most striking unfavourable outcome among smear-negative TB patients was the lost to follow-up rate. The measured proportion of treatment lost to follow-up is more than those routinely reported for all TB patients in the general population , indicating a poor retrieval performance by the healthcare providers, and the need to improve patient counselling before initiation of treatment. Also, within the subgroups, HIV-positive patients had significantly higher risk of unfavourable treatment outcomes than HIV negative patients. There is therefore need to prioritise early case finding amongst this sub-group of patients by the NTP. The NTP currently promotes TB/HIV collaborative activities . There is a need to strengthen the mechanisms for collaboration and orient it towards effective case management in the setting. The collaboration should give particular attention to patient monitoring and modification of existing referral and retrieval systems. Furthermore, 42.6% and 11.7% of HIV co-infected patients did not receive ART and CPT, respectively. This finding calls for the combined attention of the TB and HIV national programmes to optimise supervision and access to HIV care for co-infected patients. Among HIV co-infected patients, those who received ART had much better treatment outcomes. Therefore, both national programmes would benefit through more attention on getting all HIV-infected TB patients on ART.
This study had some limitations. First, the study was based on a review of routinely maintained data; thus validation of the records was difficult. However, the recording and reporting system of the NTP is monitored every 3months by the National TB Control Programme staff, who systematically review patients' personal data and quarterly reports during supervisory visits and make corrections if necessary. Second, information about possible confounders other than those investigated in this study was not available and thus could not be assessed or adjusted to decide an association. Third, selection of the study site was purposeful based on the area of work of the principal investigator. However, the site is a densely populated low-income urban slum settlement in need of an effective health system. In addition, all public and private health facilities providing TB services in the slum area participated in the study.
| Conclusions|| |
Overall, the study shows high proportion of pulmonary TB cases in Aba, particularly smear-positive TB. Among them, female patients were significantly younger compared to male patients, had higher proportions of smear-negative TB and HIV-positive status. Treatment outcomes were better among smear-positive compared to smear-negative TB patients. HIV co-infected patients had significant risk of unfavourable treatment outcomes compared to HIV-negative patients, however, those who received ART had much better outcomes. The NTP would benefit from interventions that focus on active case finding and increased access to HIV care for HIV co-infected patients.
| Conflicts of interest|| |
The authors have no competing interests to declare.
| Acknowledgements|| |
We are thankful to the National TB Programme (NTP) of Nigeria for their support. We would also like to acknowledge the support of the Abia State TB Control Programme. Our warm gratitude to all the study participants, clinic, and laboratory staffs of the health facilities for their excellent work on this study.
| References|| |
World Health Organization (WHO), Global Tuberculosis Report, 2014, World Health Organization, Geneva, Switzerland, 2014.
National Tuberculosis and Leprosy Control Programme (NTBLCP), Report of 2012 National TB Prevalence Survey, Nigeria, Federal Ministry of Health, Nigeria, 2013.
A. Hayward, T. Darton, J. Van-Tam, et al, Epidemiology and control of tuberculosis in Western European cities, Int. J. Tuberc. Lung Dis. 7 (2003) 751–757.
Q. Long, Y. Li, Y. Wang, et al, Barriers to accessing TB diagnosis for rural-to-urban migrants with chronic cough in Chongqing, China: a mixed methods study, BMC Health Serv. Res. 8 (2008) 202.
United Nations Human Settlements Programme, The Challenge of Slums: Global Report on Human Settlement, Earthscan, London, 2003.
World Health Organization (WHO), Systematic Screening for Active Tuberculosis. Principles and Recommendations,World Health Organization, Geneva, 2013.
M.A. Yassin, D.G. Datiko, O. Tulloch, et al, Innovative community-based approaches doubled tuberculosis case notification and improve treatment outcome in Southern Ethiopia, PLoS ONE 8 (2013) e63174.
D.M. Gajbhare, R.C. Bedre, H.M. Solanki, A study of sociodemographic profile and treatment outcome of tuberculosis patients in an urban slum of Mumbai, Maharashtra, Indian J. Basic Appl. Med. Res. 4 (2014) 50–57.
National Population Commission (NPC), 2006 Population and Housing Census of the Federal Republic of Nigeria: Priority Tables (Volume I), The National Population Commission, Abuja, Nigeria, 2009.
United Nations-HABITAT, The State of African Cities Report 2008, United Nations Human Settlements Programme (UNHABITAT), 2008.
National Tuberculosis and Leprosy Control Programme, Revised Workers' Manual, fifth ed., Federal Ministry of Health, Abuja, Nigeria, 2010.
S. Banu, M.T. Rahman, M.K.M. Uddin, et al, Epidemiology of tuberculosis in an urban slum of Dhaka City, Bangladesh, PLoS ONE 8 (2013) e77721.
V.G. Rao, P.G. Gopi, J. Bhat, et al, Pulmonary tuberculosis: a public health problem amongst the Saharia, a primitive tribe of Madhya Pradesh, Central India, Int. J. Infect. Dis. 14 (2010) e713–e716.
J.N. Sekandi, D. Neuhauser, K. Smyth, et al, Active case finding of undetected tuberculosis among chronic coughers in a slum setting in Kampala, Uganda, Int. J. Tuberc. Lung Dis. 13 (2009) 508–513.
Federal Ministry of Health [Nigeria], National HIV & AIDS and Reproductive Health Survey (NARHS Plus), 2012, Federal Ministry of Health, Abuja, Nigeria, 2013.
S. Rao, Tuberculosis and patient gender: an analysis and its implications in tuberculosis control, Lung India 26 (2009) 46– 47.
J. Sitienei, V. Nyambati, P. Borus, The epidemiology of smear positive tuberculosis in three TB/HIV high burden provinces of Kenya (2003–2009), Epidemiol. Res. Int. 213 (2013) 417038.
A.K. Chakraborty, Epidemiology of tuberculosis: current status in India, Indian J. Med. Res. 120 (2004) 248–276.
N.B. Hoa, C. Wei, C. Sokun, et al, Characteristics of tuberculosis patients at intake in Cambodia, two provinces in China, and Viet Nam, BMC Public Health 11 (2011) 367.
A.S. Rhines, The role of sex differences in the prevalence and transmission of tuberculosis, Tuberculosis 93 (2013) 104–107.
J.F. Austin, J.M. Dick, M. Zwarenstein, Gender disparity amongst TB suspects and new TB patients according to data recorded at the South African Institute of Medical Research laboratory for the Western Cape Region of South Africa, Int. J. Tuberc. Lung Dis. 8 (2004) 435–439.
A. Mukherjee, I. Saha, A. Sarkar, et al, Gender differences in notification rates, clinical forms and treatment outcome of tuberculosis patients under the RNTCP, Lung India 29 (2012) 120–122.
O. Neyrolles, L. Quintana-Murci, Sexual inequality in tuberculosis, PLoS Med. 6 (2009) e1000199.
World Health Organization (WHO), Global Tuberculosis Report, 2013, World Health Organization, Geneva, Switzerland, 2013.
[Table 1], [Table 2], [Table 3], [Table 4]
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