|Year : 2012 | Volume
| Issue : 4 | Page : 239-243
The proportion of patients with short duration cough (2-3 weeks) among newly detected smear-positive pulmonary TB patients; the yield of strategic change in the case detection of revised national tuberculosis control programme in an urban community setting of South India
Sujina Cheraparambil Muthukkutty, Krishnapillai Vijayakumar, Thekkumkara Surendran Nair Anish, Vijayakumar Karthik, Teena Mary Joy
Department of Community Medicine, Government Medical College, Thiruvananthapuram, Kerala, India
|Date of Web Publication||27-Feb-2013|
Thekkumkara Surendran Nair Anish
Department of Community Medicine, Government Medical College, Thiruvananthapuram
Source of Support: None, Conflict of Interest: None
Context: Tuberculosis (TB) is a public health emergency, which challenges the health indicators of India. Revised National Tuberculosis Control Programme (RNTCP) of the country has modified the definition of a pulmonary TB suspect so as to include an additional proportion of people with cough of 2 to 3 weeks duration, which will help in reducing the delay in starting treatment. Aims: To estimate the proportion of people with cough of 2-3 weeks duration among the newly diagnosed sputum-positive TB patients. Settings and Design: It is a community-based, cross-sectional study in the geographical setting of Thiruvanathapuram city corporation area, Kerala, India. Materials and Methods: The defined population in this study was tuberculosis cases registered under RNTCP for 1 year after April 2009 at the Thiruvanathapuram Tuberculosis Unit (TU). Simple random sampling procedure was done from the sampling frame, the registry of sputum-positive pulmonary cases. TB patients were interviewed when they came to the DOTS center to start the treatment. Total duration of treatment was the major outcome variable. The study protocol was approved by institutional ethical committee of government medical college, Thiruvananthapuram. Results: Proportion of people having cough of less than 3 weeks duration among newly detected TB patients and eligible for screening as per the new guideline was 32%. The analysis included data of 194 subjects with a mean (standard deviation) age of 47.5 (14.3) years. Male gender (149, 76.8%), an educational level up to secondary school (172, 88.6%), and people who were either unemployed or manual laborers (96, 49.4%) predominated in the study sample. Conclusions: In short, the study revealed that almost one third of recently diagnosed TB patients would not have been considered as 'TB suspect' before the implementation of the new strategic change. The findings support the new definition of pulmonary TB suspect in RNTCP.
Keywords: Case definition in RNTCP, cough of 2-3 weeks, smear-positive pulmonary TB, TB suspect, tuberculosis in India
|How to cite this article:|
Muthukkutty SC, Vijayakumar K, Anish TS, Karthik V, Joy TM. The proportion of patients with short duration cough (2-3 weeks) among newly detected smear-positive pulmonary TB patients; the yield of strategic change in the case detection of revised national tuberculosis control programme in an urban community setting of South India. Int J Health Allied Sci 2012;1:239-43
|How to cite this URL:|
Muthukkutty SC, Vijayakumar K, Anish TS, Karthik V, Joy TM. The proportion of patients with short duration cough (2-3 weeks) among newly detected smear-positive pulmonary TB patients; the yield of strategic change in the case detection of revised national tuberculosis control programme in an urban community setting of South India. Int J Health Allied Sci [serial online] 2012 [cited 2022 Nov 29];1:239-43. Available from: https://www.ijhas.in/text.asp?2012/1/4/239/107867
| Introduction|| |
Tuberculosis (TB) is the leading cause of morbidity and mortality among communicable diseases globally.  It has been estimated that almost one third of the world population is infected with tuberculosis (TB) and two million deaths were recorded annually.  India is one of the highest burden countries, and its health system is often challenged by the disease tuberculosis.  A large number of cases remain undiagnosed posing a big challenge to public health in India. Delayed diagnosis may result in more extensive disease, more complications, and lead to a higher mortality.  It also leads to an increased period of infectivity in the community. 
The recommended strategy to control TB in developing countries, where 95% of the tuberculosis cases occur, is to detect sputum-positive cases and treat them promptly to reduce the reservoir, ultimately leading to control of tuberculosis.  Considering the importance of the disease, Government of India started a National Programme for control of tuberculosis in 1962. The Revised National Tuberculosis Control Programme (RNTCP) based on the Directly Observed Treatment Short course (DOTS) strategy began as a pilot in 1993 and was launched as a national programme in 1997.
A pulmonary TB suspect was any person with cough for 3 weeks or more according to the original definition by RNTCP. But, there are many studies which state that at least in Indian conditions, cough for 2 weeks and 2 sputum examinations are sufficient enough to have a sensitivity as that of cough for 3 weeks and 3 sputum examinations. ,, Based on this, the National Laboratory Committee of RNTCP has made changes in the strategy for diagnosis of smear-positive pulmonary TB (PTB). New scheme came into effect from 1 st April 2009, and the new definition of pulmonary TB suspect is as follows - "A TB suspect is any person with cough for 2 weeks or more." Early detection of cases, especially sputum-positive cases, is important in public health point of view as it could prevent further spread of infection. On the other side, the new strategy could increase workload of the laboratories in carrying out sputum microscopy. In this background, it is quite interesting to study the proportion of sputum-positive TB victims with a history of cough only for 2 to 3 weeks prior to the diagnosis. This proportion may indicate the impact of the new strategy on case detection.
Aim of the current study is to estimate the proportion of patients with cough of 2-3 weeks duration among newly diagnosed sputum-positive cases residing in Thiruvananthapuram corporation area soon after the implementation of the strategic variation in RNTCP. The study also tries to illustrate the type of hospital where the diagnosis of sputum-positive pulmonary TB is made and the time delay in diagnosis at the study setting, even in presence of the symptoms.
| Subjects and Methods|| |
Study design was a community-based, cross-sectional study in the geographical setting of Thiruvanathapuram city corporation area. Thiruvanathapuram corporation has an area of 141.74 square kilometers and has a population of 744,739 according to the 2001 census. Thiruvanathapuram corporation area comes under the Thiruvanathapuram Tuberculosis Unit (TU). There are 8 designated microscopic centers (DMC) under this TU. DMCs are linked to primary health centers where the diagnosis of pulmonary TB is made based on sputum microscopy. The suspected cases of TB are referred to the DMC by the doctors based on the symptomatology.
The defined population in this study is tuberculosis cases registered under RNTCP after April 2009 at the Thiruvanathapuram Tuberculosis Unit (TU) residing in Thiruvanathapuram corporation area for 1 year. Sputum-positive pulmonary patients under the category 1 treatment regimen in RNTCP were studied. The patients not eligible for a status of TB suspect according to the revised strategy (duration of cough even less than 2 weeks) was the major exclusion criterion. Those subjects who have not given informed consent, those who are seriously ill, and those who are hospitalized were also excluded from the study.
Sample size was calculated on the assumption that the proportion of pulmonary TB positive cases presenting with cough of </=3 wks duration will be at least one third of the study population. The basis of this assumption was a pilot survey conducted at the outpatient department of respiratory medicine, government medical college, Thiruvananthapuram. The required sample size comes to be 192 to estimate the proportion with a precision of 80% and an alpha error of 5%. It was planned to conduct a simple random sampling procedure from the sampling frame, the registry of sputum-positive pulmonary cases under RNTCP and taking category 1 DOTS regimen. The new sputum-positive pulmonary cases who have registered under RNTCP after the implementation of new policy for case detection are only considered in the present study, (April 2009 onwards). TB patients were interviewed when they came to the DOTS center to start the treatment.
Data were collected using a questionnaire, which included the duration of cough as the major outcome variable. Cough with duration of at least 3 weeks were considered as a suspected symptom for screening for TB before April 2009. But, the definition of TB suspect has been modified, and even cough with duration of 2 to 3 weeks is also included in the definition. The outcome variable was categorized in to early detection or not depending upon the duration of symptoms. If the diagnosis of TB was made with duration of cough, 2-3 weeks was considered as an early detection in this paper. Socio-demographic characteristics, occupational exposures, contact with tuberculosis patients, co-morbidities and health-seeking behaviors were the exposure variables. Socio-economic status of the individuals was grouped in to below poverty line (BPL) or above poverty line (APL) based on the criteria to measure the relative poverty used by the department of revenue in the state of Kerala. The data were entered into Microsoft excel and analyzed using SPSS version 16. Means with standard deviation and proportions with confidence intervals were used to quantify the items under the study. Bivariate analysis such as unpaired t test and Chi-square test were done depending up on the nature of variables, and a P value of less than 0.05 was considered as a statistically significant difference.
A formal permission was obtained from the State Tuberculosis Officer, Kerala state to conduct a study among TB patients registered under RNTCP. The study protocol was approved by the human ethical committee of Government Medical College Thiruvananthapuram. An informed consent was taken from the study participants.
| Results|| |
The total number of TB patients enrolled in the TU during the study period was 312 and 207 (66.3%) of them were sputum-positive pulmonary TB of category 1. The total number of eligible subjects was 194 after applying the exclusion criteria. All of them were included in the analysis, and no sampling techniques were adopted. The analysis included data of 194 subjects with a mean (standard deviation) age of 47.5 (14.3) years. Among this, only 3 (1.5%) were in the age group of under 18 and 38 (19.6%) of them were above 60 years. Male gender (149, 76.8%) predominated in the study sample. Most of the TB patients (172, 88.6%) had an educational level up to secondary school, 29 (14.9%) of them were illiterate [Table 1]. Proportion of low-income group (unemployed or manual laborers) in sputum-positive TB cases was higher. Fishermen alone constituted 11% of TB cases in this study [Table 1]. Out of the 194 subjects, only 48 (25 %) mentioned a history of exposure to polluted air related to their occupation [Table 1]. Those with occupational exposure to air pollution were taxi drivers, traffic police men, road side vendors etc., [Table 1] show that the number of subjects who had a history of contact with TB cases is 38 (19.6%).
The proportion of those with any of the co-morbidities in this study is 45.6%. The co-morbidities were mainly diabetes mellitus and hypertension. Two persons were diagnosed to have human immunodeficiency virus (HIV) infection. The facility for sputum examination was available at the nearest health care delivery institution for 70% of subjects [Table 1]. The distribution of the place of diagnosis of the TB cases in the study population is given in [Table 2]. Regarding the delay in diagnosis, the mean (SD) total delay in diagnosis of TB was 7.4 (8) weeks from the first visit to the hospital. But, it took months in some cases, and the distribution was highly skewed towards the positive direction.
|Table 1: Distribution of Socio-demographic factors, exposures, and co-morbidities among the study population|
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|Table 2: Place of diagnosis of pulmonary tuberculosis among smear-positive pulmonary patients|
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The habits like smoking and alcoholism were entirely the behavior of men among the study subjects. Therefore, the analysis here is applied to this stratum alone. Seventy-five (50.3%) of them were current smokers, and 47 (31.5%) were former smokers. The mean (SD) duration of smoking was 22.5 (15.3) years. The proportion of ever alcoholics (having a history of consumption of alcohol at least once in their lifetime) was 79%, and 101 (67.8%) of them consume alcohol more than once a week, even during the time of the survey.
The number (proportion) of patients having cough of less than 3 weeks duration eligible for screening as per the new guidelines was 62 (32 %). The detection of TB among these patients can be considered as the advantage of the new policy change in RNTCP. The variables associated with the detection of TB within 3 weeks of the duration of symptoms are listed in [Table 3]. A history of contact with TB patients was found significantly associated to a detection of TB earlier.
|Table 3: Determinants of detection of tuberculosis within three weeks of symptom (Cough)|
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| Discussion|| |
The new policy change resulted in the diagnosis of 32% of patients with cough of less than 3 weeks duration according to the current study. More than 85% of them in this group had a diagnosis of TB within 3 visits to a health facility. But, the other group with chronic symptoms required more number of hospital visits to reach a diagnosis [Table 3]. The figures indicate that the new policy change in RNTCP will be beneficial in finding out the cases early, which may in turn reduce the transmission rate of tuberculosis in the community.
The age distribution of the study population was negatively skewed indicating that the disease in young adults was infrequent and TB patients were predominantly in older age bands. It may take some time for the evolution of a TB infection to a TB disease. Adults are becoming more prone to TB in the context of HIV infection also. Adding to the current findings, Chakravarthy et al. reported that the prevalence of TB peak at 55-64 years.  In consistent with the present study, studies elsewhere also report that among all ages, the prevalence was considerably higher in males than in females. ,, The reason why prevalence of TB is higher in males is not clear but may due to combination of biological, immunological, behavioral, and social factors. Some basic studies also indicated that estrogen is immunoprotective and testosterone is immunosuppressive, and these biological factors may have a role in chronic diseases like TB, in which the immunological mechanisms have a very crucial role to play.  Behavioral risk factors among men like tobacco usage and alcohol consumption may have also contributed to this difference.
The educational levels of TB patients appear to be low compared to the general population of Kerala where the rate of illiteracy is only 4.6%. The study also showed that the proportion of the poor income group was also high among the TB-affected persons. The survey carried out in Wardha District (Maharashtra) showed the prevalence of TB was inversely related to the educational status.  The social determinants of diseases like poverty, living conditions, etc., may make the low education group more prone to diseases like TB. The number of people who smoke and consume alcohol was found to be high among study subjects. Several studies showed that smoking is a risk for pulmonary TB. , Some studies showed alcoholism also to be a risk factor for tuberculosis. 
Related to diseases other than AIDS, diabetes is mentioned as a risk factor to TB.  Diabetes had been characterized as a condition that may predispose the previous tuberculosis patients to re-activation of the infection. About two fifth of the TB patients in current study were diabetic as well.
It was found that the contact with a known TB patient and the perceived severity of symptoms end-up in a faster diagnosis of TB. The patients as well as the treating physician may think about the possibility of tuberculosis in the above-mentioned situations.
In short, the study revealed that, almost one third of recently diagnosed TB patients had a history of cough of less than 3 weeks duration. The findings support the new policy change in RNTCP. A cost-effectiveness analysis may bring in more insight into this matter. The major strength of the paper is that this is the first one, which interrogates the effectiveness of the new policy. The distribution of socio-demographic factors related to tuberculosis, which is in favor of elderly and male gender, is similar to what is already known. Most of the TB victims were from poor socio-economic and were having lower levels of education. The unhealthy habits like smoking and alcoholism were also common among TB patients, and a significant proportion was suffering from a double burden contributed by other diseases, mainly diabetes.
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[Table 1], [Table 2], [Table 3]