• Users Online: 1175
  • Home
  • Print this page
  • Email this page

 Table of Contents  
Year : 2014  |  Volume : 3  |  Issue : 3  |  Page : 163-167

Diagnosis of smear-negative tuberculosis in Nigeria: Do health care workers adhere to the national guidelines?

1 German Leprosy and TB Relief Association, Enugu, Nigeria
2 University of , Enugu Campus, Nigeria
3 Department of Community Medicine, Abia State University, Aba Campus, Aba, Nigeria

Date of Web Publication27-Feb-2017

Correspondence Address:
Daniel C Oshi
German Leprosy and TB Relief Association, Enugu
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.1016/j.ijmyco.2014.07.005

Rights and Permissions

Objective: The study sought to assess the extent to which healthcare workers (HCWs) adhere to the National Tuberculosis Program (NTP) guidelines for the diagnosis of smear negative tuberculosis in Nigeria.
Method: This was a cross-sectional retrospective desk analysis of case files of 280 smear negative pulmonary TB in six States in southern Nigeria.
Results: About 93% of the 280 patients had their first set of sputum smear microscopy tests done, but only 3.6% had the second set of diagnostic tests as prescribed by the NTP guidelines. Only 45.7% (128/280) received broad spectrum antibiotics after their first smear microscopy. 98% had a chest X-ray done, while 93.6% (262/280) had HIV counseling and testing (HCT), out of which 45.0% were HIV positive. Overall, only 2 patients (0.7%) were diagnosed in strict compliance with the NTP guidelines. There was no significant difference in the pattern of diagnosis of smear negative TB cases and smear positive TB cases.
Conclusion: The adherence of HCWs to the NTP guidelines for diagnosis of smear negative TB is apparently sub-optimal and needs improvement.

Keywords: Tuberculosis, Smear negative, Diagnosis, National guidelines

How to cite this article:
Oshi DC, Chukwu JN, Nwafor CC, Aguwa EN, Onyeonoro UU, Meka A, Ikebudu JN, Anyim MC, Ekeke N, Omotowo B, Ogbudebe C, Madichie NO. Diagnosis of smear-negative tuberculosis in Nigeria: Do health care workers adhere to the national guidelines?. Int J Mycobacteriol 2014;3:163-7

How to cite this URL:
Oshi DC, Chukwu JN, Nwafor CC, Aguwa EN, Onyeonoro UU, Meka A, Ikebudu JN, Anyim MC, Ekeke N, Omotowo B, Ogbudebe C, Madichie NO. Diagnosis of smear-negative tuberculosis in Nigeria: Do health care workers adhere to the national guidelines?. Int J Mycobacteriol [serial online] 2014 [cited 2019 Oct 22];3:163-7. Available from: http://www.ijmyco.org/text.asp?2014/3/3/163/200953

  Introduction Top

Sub-Saharan Africa, including Nigeria, has witnessed a significant increase in the incidence of tuberculosis (TB) in the past few decades attributed to the increasing prevalence of HIV. The trend shows a disproportionate increase in smear negative cases relative to smear positive pulmonary TB. The diagnosis of smear negative TB in resource-poor settings is associated with significant difficulties, especially in HIV-infected patients [1],[2],[3],[4],[5]. This is believed to be a consequence of the following: the association between decreased host immunity and reduced sputum-smear positivity; difficulty in excluding other HIV-related diseases when making a diagnosis of smear-negative PTB; and an increase in false-negative sputum smears because of overstretched resources [6].

The World Health Organization (WHO) recommends that the diagnosis of sputum smear-negative pulmonary TB should be based on the following criteria: at least 2 negative sputum smears (including at least 1 early-morning specimen); chest radiography findings consistent with TB; and lack of a response to a trial of broad-spectrum antimicrobial agents. For such patients, if facilities are available, sputum cultures should be obtained. In persons with known or suspected HIV infection, the diagnostic evaluation should be expedited [7]. Although non-response to the broad spectrum antibiotics may suggest TB, a positive response does not exclude it. The primary goal of an antibiotics trial is to treat concomitant bacterial infections that are common both in TB and non-TB patients [8].

In resource-constrained settings, the diagnosis of sputum smear-negative pulmonary TB relies heavily on the clinical judgement of a medical officer, both in the interpretation of the chest radiograph as well as the assessment of the patient's clinical status. Thus, making a diagnosis of smear-negative pulmonary TB is more or less subjective depending on the expertise of the physicians, particularly in settings where sputum culture is not available.

Previous studies have highlighted the need for an accurate and prompt diagnosis of smear negative pulmonary TB. Misdiagnosis of smear negative pulmonary TB often results in low coverage of early treatment, increased transmission of the disease, increased morbidity and an untimely death. At the same time, diagnosing or classifying individuals who do not have the disease as smear positive patients also leads to wastage of valuable resources, including time and materials [1].

Although operational research is necessary to determine the most cost-effective approaches to the diagnosis and treatment of smear-negative PTB, substantial improvement could be obtained by implementing the effective measures already available, such as improved adherence to diagnostic and treatment guidelines. In recognition of these challenges and the threat posed by the HIV epidemic, a number of countries have revised their protocol to accommodate these developments.

In Nigeria, the algorithm for diagnosis of sputum smear negative pulmonary TB is as shown below [9] (see [Figure 1]).
Figure 1: National algorithm for diagnosis of TB.

Click here to view

The objectives of the algorithm are to ensure standardization of diagnosis and reduce the delay in diagnosis, as well as provide a basis for monitoring the quality of the National TB Program (NTP). However, since adoption of the guidelines, there has not been any systematic effort to validate them for sensitivity and specificity and/or assess the level of compliance by health workers in the field. This study is aimed at ascertaining the degree of compliance to the NTP guidelines by health workers at the primary, secondary and tertiary levels of the healthcare delivery system. The main issues looked at include: the pattern of diagnosis of smear-negative PTB and the degree to which clinicians actually followed the criteria for diagnosing smear negative PTB in practice.

  Methodology Top

The study was carried out in selected healthcare facilities supported by the German Leprosy and Tuberculosis Relief Association (GLRA) in six States in southern Nigeria. The States include: Ebonyi and Enugu in the south-east geopolitical zone; Bayelsa and Rivers in the south-south zone; and Ekiti and Ogun in the south-west zone. From each State, the healthcare facilities were selected purposively in the ratio of 2:6:2 for tertiary, secondary and primary healthcare facilities, respectively. Case files of all sputum smear negative pulmonary TB cases seen in the second quarter of 2010 (April to June) were selected and reviewed using a questionnaire. The following data were collected: age, sex, sputum smear result (1st and 2nd batches), CXR, HIV counseling and testing (HCT), administration of antibiotics, date of commencement of treatment following diagnosis, and whether the patient was seen by a medical officer.

Data collected were entered and analyzed using SPSS version 17. Findings were presented using relevant frequency tables, and the test of association was carried out using chi-square test. P-Value of 0.05 was assumed to be statistically significant.

Limitation of the study

CXR findings were not included, and the basis of diagnosis of smear-negative PTB was not specified.

  Result Top

A total of 280 patient records were reviewed comprising 143 (51.1%) females and 137 (48.9%) males (see [Table 1]).
Table 1: Socio-demographic characteristics of the patients.

Click here to view

More than half of the patients studied (56.1%) were aged between 25 and 44 years. One hundred and fifty patients (54.2%) visited a secondary health care facility; the remainder visited either a primary (23.6%) or tertiary (22.1%) healthcare facility. The majority of them (92.5%) were attended to by a medical doctor, and they included all but one of those who visited a tertiary health facility, and 94.7 and 81.8% of those who visited secondary or primary healthcare facilities, respectively. About 93% of the subjects had a first set of sputum smear diagnostic tests done, while only 3.6% of the patients did the second set of sputum smear tests. One hundred and twenty-eight (45.7%) of them received broad-spectrum antibiotics after the first set of sputum smear results and were asked to return after completing treatment. About 90% of them had a chest radiograph done. HIV counseling and testing (HCT) was offered to 262 (93.6%) patients, and a total of 118 patients (45.0%) were HIV positive, while the remainder (55.0%) were HIV negative.

Only two (0.7%) patients were diagnosed in total compliance with the diagnostic criteria, which included two smear negative results, two-week antibiotics trial, and a chest radiograph prior to commencing anti-TB therapy, as well as HCT (see [Table 2]).
Table 2: Pattern of management of smear-negative PTB at various levels of health facilities.

Click here to view

Some of the patients managed in secondary (4.6%) and tertiary (19.3%) healthcare facilities were diagnosed without a sputum smear result. A greater proportion (66.1%) of those treated in the tertiary healthcare facilities was more likely to have received broad-spectrum antibiotics. Most of those who were not offered HCT were from the secondary healthcare facilities (11.2%); while about 20% and 10% of those seen in the primary and secondary healthcare facilities respectively had no chest radiograph. Although, primary healthcare facilities (50.0%) reported the highest proportion of HIV positive cases, there was no significant difference in proportion of HIV positive cases relative to the level of healthcare facilities (X2= 1.08, p = 0.583). The likelihood of having a chest radiograph done was associated with a higher level of healthcare facility. Patients seen in the tertiary facilities were less likely to have commenced treatment within 6days of the first batch of sputum results (X2 = 17.62, p = 0.007) (see [Table 3]).
Table 3: Pattern of management of Sputum-smear PTB in relation to HIV serostatus.

Click here to view

There was no significant difference in pattern of management of sputum-smear PTB between HIV positive and HIV negative patients except for timing of commencement of anti-TB therapy. Those who were commenced on treatment at 14 weeks or more were more likely to be HIV positive (X2 = 6.19; p = 0.045).

  Discussion Top

Healthcare facilities for the management of TB in Nigeria cut across all levels of healthcare. Although the secondary healthcare facilities accounted for most of the case load seen in this study, in various States the level and type of health facility that accounts for a greater proportion of case loads vary in accordance with functionality and access. Until recently, there was limited involvement of tertiary healthcare facilities in Directly Observed Treatment Strategy (DOTS), which is the primary strategy for TB control in the NTP. An increasing incidence of sputum smear negative PTB in the country now provides the basis for their greater involvement in the NTP. Patients who visited primary healthcare facilities were less likely to be seen by a medical officer because most primary healthcare facilities in the country do not have medical officers.

The study revealed that sputum smear negative TB was often diagnosed without compliance with the national TB control program guideline/protocol. Reasons for non-compliance were not identified; however, low awareness and poor commitment to following the national guidelines were probable reasons. Harries et al. [10] reported that improved adherence to existing guidelines for diagnosis and treatment could go a long way in improving TB care and outcome. Contrary to the national guidelines, most of the patients were diagnosed without two smear negative results, and less than half of them received antibiotics trial despite having a chest radiograph done. Primary healthcare facilities most times do not have radiology services, so patients requiring such services are often referred to higher levels of healthcare. However, access to such services may be limited by distance and cost and may account for a delay in diagnosis of smear negative PTB. In Nigeria, a weak referral system and support constitute a major weakness in the country's healthcare system [11],[12]. Chest radiograph findings – though they may not be specific – still constitute an important tool in the diagnosis of sputum smear negative PTB. Higher healthcare facilities were more likely to prescribe antibiotics in the management of suspected smear-negative PTB cases. Consequently, the interval in the completion of antibiotics might have accounted for the delay in initiating treatment seen in tertiary healthcare facilities.

Forty-five per cent of the patients treated were HIV positive. Thus, this study also compared steps taken to manage smear negative PTB from diagnosis until commencement of treatment between HIV positive and HIV negative individuals, but did not assess treatment outcome. It is evident from the study that patients were subjected to the same diagnostic protocol irrespective of their HIV sero-status. Sadly, the HIV-positive individuals were more likely to have commenced anti-TB treatment later compared with the HIV negative individuals. The advent of HIV has resulted in a number of countries revising their algorithm for management of smear negative TB in line with WHO recommendations so as to reduce time taken to diagnose TB in HIV-positive individuals, address challenges of atypical presentation of TB associated with HIV disease and the need to exclude other opportunistic diseases that present like TB. Revision of the guideline became necessary to improve case detection, reduce the burden of co-morbidity and reduce the mortality associated with both illnesses, as HIV-positive patients suffering from TB are more likely to deteriorate faster and die [4],[5],[6].

In conclusion, this study highlights the need to carry out further studies to identify factors responsible for non-adherence to the national TB guidelines in the diagnosis of sputum smear negative PTB. The implication of the study is that assessment of adherence to TB management protocol or guideline is a measure of quality assurance, hence a measure of performance of the National TB Control Program. Also, in line with the recommendation of Harries et al. [10], there is a need to validate the current guidelines in line with the current realities, particularly the HIV epidemic which has altered the previously known parameters of the management of smear negative pulmonary TB.

  Conflict of interest Top

None declared.

  Acknowledgement Top

The authors are grateful to TBCAP for their financial support.

  References Top

G.S. Mfinanga, E. Ngadaya, R. Mtandu, et al, The quality of sputum smears microscopy diagnosis of pulmonary tuberculosis in Dar es Salaam, Tanzania, Tanzania Health Res. Bull. 9 (2007) 3.  Back to cited text no. 1
M. Dimairo, P. MacPherson, T. Bandason, et al, The risk and timing of tuberculosis diagnosed in smear-negative TB suspects: a 12 month cohort study in Harare, Zimbabwe, PLoS ONE 5 (2010) 7.  Back to cited text no. 2
E.E. Nwokedi, I. Jahun, Laboratory confirmation of clinically suspected cases of pulmonary tuberculosis in Kano, Nigeria, Afr. Sci. 9 (1) (2008).  Back to cited text no. 3
E. Girardi, A.M. Pellicelli, A. Rianda, et al, Pulmonary tuberculosis in HIV-infected patients presenting with normal chest radiograph and negative sputum smear, Infection 30 (2) (2002) 68–74.  Back to cited text no. 4
R. Colebunders, I. Bastian, A review of the diagnosis and treatment of smear-negative pulmonary tuberculosis, Int. J. Tuberculosis Lung Dis. 4 (2) (2000) 97–107.  Back to cited text no. 5
H. Getahun, M. Harrington, R. O'Brien, P. Nunn, Diagnosis of smear-negative pulmonary tuberculosis in people with HIV infection or AIDS in resource-constrained settings: informing urgent policy changes, Lancet 369 (9578) (2007) 2042–2049.  Back to cited text no. 6
Approach to diagnosing sputum smear-negative TB. Interim Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis. 2008. www.carec.org.  Back to cited text no. 7
D. Wilkinson, K.M. De Cock, A.W. Sturm, Diagnosing tuberculosis in a resource-poor setting: the value of a trial of antibiotics, Trans. R. Soc. Trop. Med. Hyg. 91 (1997) 422–424.  Back to cited text no. 8
FMOH, National TB treatment Guidelines, FMOH, Abuja, 2007.  Back to cited text no. 9
A.D. Harries, D. Maher, P. Nunn, An approach to the problems of diagnosing and treating adult smear-negative pulmonary tuberculosis in high-HIV-prevalence settings in sub-Saharan Africa, Bull. World Health Org. 76 (6) (1998) 651–662.  Back to cited text no. 10
SMOH, Situation Analysis of Integrated Maternal, Neonatal, Child Health – Abia State, SMOH, Umuahia, 2009.  Back to cited text no. 11
I.P. Chudi, Healthcare problems in developing countries, Med. Pract. Rev. 1 (1) (2010) 9–11.  Back to cited text no. 12


  [Figure 1]

  [Table 1], [Table 2], [Table 3]

This article has been cited by
1 Governance of tuberculosis control programme in Nigeria
Daniel Chukwuemeka Ogbuabor,Obinna Emmanuel Onwujekwe
Infectious Diseases of Poverty. 2019; 8(1)
[Pubmed] | [DOI]
2 Smear microscopy as a diagnostic tool of tuberculosis: Review of smear negative cases, frequency, risk factors, and prevention criteria
Tarig M.S. Alnour
Indian Journal of Tuberculosis. 2018;
[Pubmed] | [DOI]
3 Protocol for a qualitative synthesis of barriers and facilitators in implementing guidelines for diagnosis of tuberculosis
Eleanor Ochodo,Tamara Kredo,Taryn Young,Charles Shey Wiysonge
BMJ Open. 2017; 7(6): e013717
[Pubmed] | [DOI]
4 Are Tuberculosis Patients Managed According to the National Guidelines in Lagos State Nigeria?
Olusola Adedeji Adejumo,Olusoji James Daniel,Mustapha Gidado,Andrew Folarin Otesanya,Esther Ngozi Adejumo,Ebunoluwa O. Jaiyesimi,Oluwatoyin Esther Idowu,Olumuyiwa O. Odusanya
International Journal of Clinical Medicine. 2016; 07(01): 16
[Pubmed] | [DOI]


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
Conflict of interest
Article Figures
Article Tables

 Article Access Statistics
    PDF Downloaded43    
    Comments [Add]    
    Cited by others 4    

Recommend this journal