Biomedical and Biotechnology Research Journal (BBRJ)

ORIGINAL ARTICLE
Year
: 2019  |  Volume : 3  |  Issue : 2  |  Page : 109--110

Smear-negative pulmonary tuberculosis: Relative incidence and outcome of treatment in a drug-resistant endemic setting in Indochina


Pathum Sookaromdee1, Viroj Wiwanitkit2,  
1 TWS Medical Center, Bangkok, Thailand
2 Department of Biological Science, Joseph Ayobabalola University, Ilara-Mokin, Nigeria

Correspondence Address:
Dr. Pathum Sookaromdee
TWS Medical Center, Bangkok
Thailand

Abstract

Background: Pulmonary tuberculosis is an important public health problem at present. The disease is still highly prevalent in several areas including tropical Indochina. In the area between Thailand and Myanmar body, the emerging drug-resistant tuberculosis is an interesting problem in the present day. Early diagnose and management of tuberculosis patient is important. Methods: In this specific article, the authors summarize and discuss on the locally available data on smear-negative pulmonary tuberculosis in a drug-resistant endemic foci in Indochina. The relative incidence and the outcome of the treatment are specifically focused. Results: Based on the present study, the outcome of the treatment of cases with smear-negative pulmonary tuberculosis is similar to cases with smear-positive pulmonary tuberculosis. Conclusion: Since the outcome of the treatment of cases with smear-negative pulmonary tuberculosis is similar to cases with smear-positive pulmonary tuberculosis, therefore, it is recommended for therapeutic management of those cases.



How to cite this article:
Sookaromdee P, Wiwanitkit V. Smear-negative pulmonary tuberculosis: Relative incidence and outcome of treatment in a drug-resistant endemic setting in Indochina.Biomed Biotechnol Res J 2019;3:109-110


How to cite this URL:
Sookaromdee P, Wiwanitkit V. Smear-negative pulmonary tuberculosis: Relative incidence and outcome of treatment in a drug-resistant endemic setting in Indochina. Biomed Biotechnol Res J [serial online] 2019 [cited 2019 Oct 13 ];3:109-110
Available from: http://www.bmbtrj.org/text.asp?2019/3/2/109/260475


Full Text



 Introduction



Pulmonary tuberculosis is a mycobacterium lung infection. This infection is an important public health problem at present. At present, pulmonary tuberculosis is still highly prevalent in several areas including tropical Indochina. In the area between Thailand and Myanmar body, the emerging drug-resistant tuberculosis recently emerged. The emergence of the drug-resistant tuberculosis becomes the important problem in the present day.

To mange drug-resistant tuberculosis, early diagnose and management of the patient is necessary. In this specific article, the authors summarize and discuss on the locally available data on smear-negative pulmonary tuberculosis in a drug-resistant endemic foci in Indochina. The relative incidence and the outcome of the treatment are specifically focused.

 Methods



This is a retrospective study on the available clinical record on pulmonary tuberculosis management in a Thailand–Myanmar border province, namely Tak in Thailand. The clinical data in the year 2012 are summarized and analyzed. The registered cases are classified into smear-negative pulmonary tuberculosis and smear-positive pulmonary tuberculosis. The outcome of treatment in smear-negative pulmonary tuberculosis and smear-positive pulmonary tuberculosis was assessed by Chi-square test. The protocol for this clinical record assessment and analysis is ethically approved by the Ethical Committer of the Medical Center (Approval number TWS 2018-15, aproved on 2018 April 2018, Bangkok Thailand).

 Results



According to the study, there are 538 cases of registered pulmonary tuberculosis. There are 101 smear-negative pulmonary tuberculosis (18.77%) and 437 smear-positive pulmonary tuberculosis (81.23%) cases. All cases received standard pulmonary tuberculosis treatment. The outcomes of treatment in smear-negative pulmonary tuberculosis and smear-positive pulmonary tuberculosis are presented in [Table 1]. From overall 538 cases, there are 5 cases with failure treatment (0.93%).{Table 1}

For the cases with positive smear, successful treatment can be seen in 99.1% (433 from 437 cases). For the cases with negative smear, successful treatment can be seen in 99% (100 from 101 cases). There is no association between outcomes of treatment and the positivity/negativity of smear (P > 0.05).

 Discussion



Diagnostic difficulty for pulmonary tuberculosis is usually due to the no clear-cut laboratory finding.[1] In case with negative sputum smear result for acid-fast bacilli but the patient has a clinical manifestation and chest radiographs looks like tuberculosis, it is usually a diagnostic difficulty.[1],[2] The confirmation by sputum culture might be needed, but this test might not be available in some settings, and the culture result might also be negative. In addition to the standard culture test, the new molecular diagnosis might be helpful, but it is no doubt that it is hardly available in remoted area with resource limitation.[2],[3]

Regarding the incidence of the smear-negative pulmonary tuberculosis, several cases have negative smear. The relatively high incidence of negative smear pulmonary tuberculosis in our setting implies the need for improvement of diagnostic system in our setting. In the present study, the authors summarize the data from a border area where the facilities are usually limited. The diagnosis of tuberculosis by culture is usually not available. The management of smear-negative pulmonary tuberculosis by standard antituberculosis drug is performed, and it seems that the management can usually result in curative treatment. The important factor for management of the case is usually the attachment to drug treatment.[4] Loss of follow-up is the main cause of treatment failure.[4] As noted by Singla et al., interruption in intensive phase of treatment is an independent risk factor for sputum smear positivity and associated with poor tuberculosis therapy outcome.[5] On the other, the medical practitioner has to strictly follow the standard guidelines for the diagnosis and management of tuberculosis.[6]

At present, the sputum examination by microscopic investigation is still the basic standard test for the detection of tuberculosis. The microscopy has low cost and performing the examination is rapid and simple. Furthermore, the microscopy has high specificity. Nevertheless, the main problem is on the diagnostic sensitivity that limits the usefulness for active disease finding.[7] There should be an implementation of the new diagnostic tool for help to detect tuberculosis in cases with negative sputum test. The good example of the new tuberculosis test is GeneXpert MTB/RIF® assay, which can help increase the chance for identification of tuberculosis within a short turnaround time.[8]

 Conclusion



Based on the present study, the outcome of the treatment of cases with smear-negative pulmonary tuberculosis is similar to cases with smear-positive pulmonary tuberculosis.[1] At present, it is recommended for therapeutic management of those cases.[1]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Dutt AK, Stead WW. Smear-negative pulmonary tuberculosis. Semin Respir Infect 1994;9:113-9.
2Ryu YJ. Diagnosis of pulmonary tuberculosis: Recent advances and diagnostic algorithms. Tuberc Respir Dis (Seoul) 2015;78:64-71.
3Tesgaye F, Defar A, Beyene T, Shafi O, Klinkenberg E, Howe R, et al. Documentation and treatment outcomes of smear-negative and extra-pulmonary tuberculosis in Ethiopia. Public Health Action 2014;4:S25-30.
4Tian P, Shen Y, Wang Y, Wan C, Feng M, Zhu J, et al. Diagnostic value of nucleic acid amplification tests on bronchoalveolar lavage fluid for smear-negative pulmonary tuberculosis: A meta-analysis. Biosci Rep 2015;35. pii: e00232.
5Singla R, Bharty SK, Gupta UA, Khayyam KU, Vohra V, Singla N, et al. Sputum smear positivity at two months in previously untreated pulmonary tuberculosis patients. Int J Mycobacteriol 2013;2:199-205.
6Oshi DC, Chukwu JN, Nwafor CC, Aguwa EN, Onyeonoro UU, Meka A, et al. Diagnosis of smear-negative tuberculosis in Nigeria: Do health care workers adhere to the national guidelines? Int J Mycobacteriol 2014;3:163-7.
7Singhal R, Myneedu VP. Microscopy as a diagnostic tool in pulmonary tuberculosis. Int J Mycobacteriol 2015;4:1-6.
8Tadesse M, Aragaw D, Rigouts L, Abebe G. Increased detection of smear-negative pulmonary tuberculosis by GeneXpert MTB/RIF® assay after bleach concentration. Int J Mycobacteriol 2016;5:211-8.