Recent development in preparation of food packaging films using biopolymers

In the past decades, most materials used in the food packaging industry are nonbiodegradable materials that pose increased environmental concerns and sustainability issues. Hence, polymer-based biodegradable materials and edible films have been developed to increase the shelf life of food products. Especially, biopolymer-based nanomaterials are engineered with multifunctional characteristics because of their size, surface area, shelf life, thermal stability, and mechanical and barrier strength. These materials display enriched properties of biodegradability, antimicrobial activity, and biocompatibility and may have the possibility to replace plastic materials in future. Thus, this review offers a brief overview of the classification of biopolymers, key parameters that are important in food packaging films (including the role of plasticizers, cross-linkers, pH, temperature, and relative humidity), and recent applications of novel biopolymer nanocomposite materials used in the food industries.

Abstract P5-05-12: Progesterone drives ER-positive and triple negative breast cancer cell proliferation through progesterone receptor membrane component 1

Introduction: The role of progesterone and its receptors in breast cancer progression continue to be studied but remain controversial. Progesterone membrane receptors with the ability to regulate kinase signals, mediating breast cancer proliferation have been demonstrated. Increased expression of the Progesterone Receptor Membrane Component 1 (PGRMC1), a heme – binding protein with the ability to interact and stabilize epidermal growth factor receptor (EGFR) is frequently found in breast cancer tissue. Some evidence suggests that progesterone can stimulate and regulate breast cancer cell proliferation. The basis of the signaling mechanisms by which Progesterone exerts its function remains largely unknown. Both the nuclear and membrane progesterone receptors could play a significant role in the development and progression of breast cancer and both could become viable therapeutic options. We, aim to investigate the role of PGRMC1 in progesterone driven breast cancers.

Materials and Methods: Human breast tissues were utilized to identify PGRMC1 expression along with a panel of normal and breast cancer cell lines. Two breast cancer cell lines (ZR-75-1 and MDA-MB-468) were selected and treated with progesterone and AG-205 (PGRMC1 inhibitor) at different concentrations to assess optimum dosage. We performed MTS assay, qRT-PCR, Western blot, immunofluorescence, immunohistochemistry and flow cytometry for measuring cell proliferation, apoptosis and key markers involved in these processes. We also performed an in silico analysis to compare the expression of PGRMC1 in various cell lines and breast cancer tissues.

Results: Immunohistochemistry demonstrated strong staining for PGRMC1 in human breast cancer tissue compared to normal tissue. Increased PGRMC1 expression was observed specifically in ZR-75-1 and MDA-MB-468 cells by qRT-PCR, western blot and immunofluorescence, these results were validated and compared to microarray-based gene expression analysis of breast cell lines and breast tumor data sets. Progesterone treatment increased cell proliferation in a dose dependent manner while AG-205 decreased cell proliferation in a dose dependent manner in ZR-75-1 and MDA-MB-468. Minimal effects of AG-205 were observed in normal breast epithelial cells. AG-205 also, induced apoptosis in both ZR-75-1 and MDA-MB-468 cell lines. Furthermore, short-term treatment of progesterone increased both mRNA and protein expression of PGRMC1. Key markers of cell proliferation (pAKT, CCND1, pEGFR, pmTOR) and apoptosis (PTEN, Bcl2, Bax, Bim) revealed that PGRMC1 facilitated the proliferative effect of progesterone. Interestingly progesterone increases phosphorylation of EGFR and treatment of AG-205 alters EGFR expression in a dose dependent manner.

Conclusion: Our data demonstrates that PGRMC1 plays a prominent role in regulating progesterone driven cell proliferation in both ER-positive and triple negative breast cancer cells. These initial findings uncover the potential of PGRMC1 as a therapeutic target for breast cancers.

Citation Format: Pedroza DA, Subramani R, Galvez A, Lakshmanaswamy R. Progesterone drives ER-positive and triple negative breast cancer cell proliferation through progesterone receptor membrane component 1 [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-05-12.

Abstract P5-05-15: Pregnancy inhibits mammary carcinogenesis by persistently altering the hypothalamic-pituitary axis

Pregnancy, carried to term at an early age, is probably the best natural protection against breast cancer development. The relative life-long breast cancer risk for women that give birth to their first child before the age of 20 years is approximately half that of nulliparous women. In contrast, if a woman undergoes her first full-term pregnancy after the age of 35, her risk for breast cancer is increased even more than nulliparous women. In the current generation many women are career oriented and have children later in life. Universally the average age at first birth is on the rise. It is critical to understand the underlying mechanism of this protective effect of pregnancy against breast cancer to develop novel prevention strategies to reduce the risk of breast cancer without women having to undergo pregnancy early in life. Earlier, we and others have demonstrated that post-pregnancy there were persistent changes in circulating levels of hormones. In order to understand the significance of these systemic changes we determined alterations in the hypothalamic-pituitary axis in parous rats. In particular, we examined the static and dynamic alterations in the hypothalamic-pituitary axis in response to pregnancy. Seven weeks old female Lewis rats were injected with the chemical carcinogen N-methyl-N-nitrosourea (MNU) at a dose of 50mg/kg body weight intraperitoneally. Two weeks post-carcinogen treatment these rats were housed with a male rat. On the observation of the vaginal plug the male was removed from the cage. Once the rats gave birth they nursed the pups for three weeks and were weaned after that period. Mammary tumorigenesis was monitored through weekly palpation for a period of nine months. A subset of rats at 6, 12 and 24 weeks post-weaning were used to study static and dynamic changes in the level of hormones. We investigated the static alterations in the hypothalamic-pituitary axis in response to pregnancy by measuring the levels of thyrotropin releasing hormone (TRH), growth hormone releasing hormone (GHRH), somatostatin (SS), dopamine (DA), growth hormone (GH) and prolactin (PRL). Next we investigated if the dynamic alterations in the hypothalamic-pituitary axis in response to pregnancy. Control and parous animals were subjected to secretogogue treatments (Growth Hormone Related Peptide 6 for GH and Perphenazine for PRL) and the levels of GH and PRL were measured. We also isolated the pituitary and treated them with the secretogogues and measured the levels of GH and PRL. Our data demonstrated that pregnancy resulted in persistent static and dynamic alterations in circulating levels of hormones. Parous rats response to the secretogogues was severely blunted compared to the control nulliparous rats. The levels of TRH, GHRH, GH and PRL were significantly lowered in parous rats while DA and SS levels were higher in nulliparous rats. As expected mammary carcinogenesis was significantly inhibited in parous rats. Overall, these preliminary results suggest that pregnancy induces persistent changes in hypothalamic-pituitary axis, which results in a lowered hormonal promotion environment resulting in inhibition of mammary carcinogenesis.

Citation Format: Subramani R, Galvez A, Pedroza D, Lakshmanaswamy R. Pregnancy inhibits mammary carcinogenesis by persistently altering the hypothalamic-pituitary axis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-05-15.

Role of bacille Calmette-Guérin in preventing tuberculous infection

SETTING

Rural community in South India.

OBJECTIVE

To determine the role of bacille Calmette-Guérin (BCG) in preventing tuberculous infection in children.

DESIGN

A prevalence survey was undertaken in 1999-2001 in a representative rural population in Tiruvallur District in South India using cluster sampling. Tuberculin testing was performed among all children aged <15 years, and all adults aged 15 years were questioned about chest symptoms and underwent radiography, followed by sputum examinations, if indicated.

RESULTS

In children living in households with a tuberculosis case, the proportion with evidence of tuberculous infection was 35.5% of 200 in the absence of a BCG scar and 27.0% of 100 in its presence, a reduction of 24% (P = 0.14). In very young children (age <5 years), the corresponding proportions were 29.1% of 55 and 11.9% of 42, a reduction of 59%; the difference was statistically significant (P = 0.048).

CONCLUSION

There is a possible role for BCG in preventing tuberculous infection in very young children.

Tuberculosis mortality in a rural population from South India

BACKGROUND

General mortality rate (GMR) is an essential indicator for assessing the health status of a community. Tuberculosis (TB) mortality is an indicator for the Millennium Development Goal for 2015.

METHODS

This community-based retrospective survey was conducted in 2007-2008 on a sample of 114,605 rural populations living in 56 villages randomly selected from 218 villages in Tiruvallur district, South India, where the DOTS strategy was implemented in 1999. All the permanent residents of the households were registered and information on occurrence of death was recorded. All the deaths were investigated by verbal autopsy (VA) using standardized methods.

RESULTS

A total of 719 deaths were registered. The GMR and tuberculosis mortality rate (TMR) were 648 (95% CI: 568-727) and 39 (95% CI: 25-52) per 100,000 p-yrs, respectively. The GMR increased with age, and was higher in males than females at all ages. The TMR was higher in males than females and the overall male:female ratio was 5:1.

CONCLUSION

TB was the 6th leading cause of death overall and the 2nd leading cause among men in this area. Strategies to reduce TB death should be implemented and the impact should be monitored by repeat VA studies.

General and tuberculosis mortality in two states of India: A population-based survey

BACKGROUND

General and cause-specific mortality data for causes of death are not available for the states of Andhra Pradesh (AP) and Orissa in India.

OBJECTIVES

To estimate general mortality rate (GMR) and the tuberculosis mortality rate (TMR) among the general population in the two states.

METHODS

All permanent residents in households of selected districts of AP and Orissa states were registered in the survey in 2005-2006. A sample size of 380,000 persons was selected from each state. Health workers carried out house-to-house enumeration. Demographic and occurrence of death data were collected. The cause of death was determined using the instrument of verbal autopsy.

RESULTS

The GMR for AP and Orissa was 636 (95% CI: 610-662) and 616 (95% CI: 588-643) per 100,000 person years (p-ys) respectively. The TMR for AP and Orissa was 76 (95% CI: 67-85) and 41 (95% CI: 34-48) per 100,000 p-ys respectively. The difference in TMR between the states was statistically significant (P<0.0001).

CONCLUSION

The GMRs are similar in AP and Orissa states. Tuberculosis accounted for 12% and 7% of deaths in AP and Orissa respectively. Focused strategies are needed to reduce mortality due to tuberculosis.

Could repeated prevalence surveys lead to decreasing tuberculosis prevalence in a community?

SETTING

Tiruvallur District, South India, where one baseline tuberculosis (TB) disease prevalence survey followed by three repeat prevalence surveys were conducted every 2.5 years between 1999 and 2008, and where the DOTS strategy was implemented in 1999.

OBJECTIVE

To rule out the possibility that the observed decline in TB prevalence was influenced by conducting repeat prevalence surveys, we compared the findings from two surveys: the third repeat survey conducted in 2006-2008 and an independent single survey in a neighbouring area conducted in 2008-2009.

DESIGN

An independent survey was conducted to estimate the prevalence of TB in the same district in 2008-2009 using a different set of villages and employing repeat survey methodology. The independent survey findings were compared with those of the third repeat survey.

RESULTS

The estimated prevalence rate of culture- and smear-positive TB was respectively 401 per 100,000 and 186 per 100,000 population in the third repeat survey area. The corresponding rates were 340 and 184/100,000 in the independent survey area. The difference in prevalence was not significant (culture P = 0.09; smear P = 0.93).

CONCLUSION

The estimated prevalence rates in the two different sample survey areas were comparable, indicating that the repeated prevalence surveys in the study area did not influence the observed decline in TB disease prevalence.

Trends in the prevalence of pulmonary tuberculosis over a period of seven and half years in a rural community in south India with DOTS

SETTING

Tiruvallur district In Tamil Nadu where DOTS was implemented by the State Government as the tuberculosis control measure in 1999, and monitored by the National Institute for Research in Tuberculosis for over five years.

OBJECTIVE

To estimate trends in TB prevalence in a rural community with DOTS.

DESIGN

Surveys of pulmonary tuberculosis were undertaken in representative samples of subjects aged > or =15 years (N = 83,000 - 92,000), initially and after two and half, five and seven and half years of implementation of DOTS. Sputa were collected from those with abnormal radiograph and/or presence of chest symptoms, and examined by direct smear and culture.

RESULTS

The prevalence of culture-positive tuberculosis was 607, 454, 309 and 388 per 100,000 in the four surveys, and that of smear-positive tuberculosis was 326, 259, 168 and 180. In the first five years; annual decrease was 12.4% (95% CI 10.4 - 14.4%) for culture-positive tuberculosis, and 12.2% (95% CI 8.0-16.2) for smear-positive tuberculosis. This was, however, followed by a significant increase in the next two and half years. The average new smear-positive case-notification rate was 75 per 100,000 during first four years but declined to 49 in subsequent years. There were no methodological differences during this period and information on changes in socio-economic indicators and nutritional standards was unavailable.

CONCLUSION

Despite the average annual success rate (78%) in this tuberculosis unit being lower than the expected rate of 85%, the implementation of DOTS was followed by a substantial decrease in the prevalence of pulmonary tuberculosis over the seven and half year period. Our findings suggest that sustaining the high effectiveness of DOTS programme needs vigilant supervision.

Trend in tuberculosis infection prevalence in a rural area in South India after implementation of the DOTS strategy

SETTING

Three tuberculin surveys were conducted at intervals of 5 years following the implementation of a DOTS-based programme in 1999 in Tiruvallur District, South India.

OBJECTIVE

To estimate the trend in the prevalence of tuberculosis (TB) infection among children and to evaluate the impact of the DOTS strategy.

METHODS

Children aged 1-9 years in the sample for each survey were registered and administered 1 tuberculin unit of purified protein derivative RT 23 with Tween 80 by intradermal injection on the volar aspect of the left forearm. The induration diameter of the reaction was measured in mm after 72 h (3 days) and the prevalence of TB infection estimated.

RESULTS

The induration data of bacille Calmette-Guérin (BCG) vaccinated and non-vaccinated children were analysed using the mixture model. The estimated prevalence of TB infection among non-BCG-vaccinated children in the three tuberculin surveys were respectively 19.4%, 13.8% and 11.4%, with an average annual decline of 5.2% (95%CI 3.6-6.8). The prevalence of TB infection among BCG-vaccinated children decreased, with an average annual decline of 5.4% (95%CI 10.0-18.6).

CONCLUSION

A significant declining trend in the prevalence of TB infection among children was observed following the implementation of the DOTS strategy in the area.

DOTS reaches socially marginalized population in the community: a study from a rural area of South India

We report here that the Directly Observed Treatment, Short course (DOTS) is reaching all tuberculosis patients in the community irrespective of social classification based on the analysis from the tuberculosis prevalence survey and programme performance during 1999-2003 from a rural area in Tamilnadu, South India. New smear- positive cases treated under a DOTS programme were classified in two groups namely; scheduled caste living in colony and other population. The prevalence of smear- positive cases among the scheduled caste population was 1.9 times higher than the other population and this was reflected in the notification also. The successful treatment outcome was also similar in these two groups (75% and 78% respectively; overall 77%). From these findings it is concluded that people living in colony have equal access to DOTS as those in the village.

Association between biomass fuel and pulmonary tuberculosis: a nested case-control study

OBJECTIVE

To quantify the association between biomass fuel usage and sputum-positive pulmonary tuberculosis.

METHODOLOGY

A tuberculosis prevalence survey was conducted in a random sample of 50 rural units (villages) and three urban units in the Tiruvallur district of Tamilnadu, India during the period 2001-2003. Additional data regarding exposure to tobacco smoking, alcohol consumption, biomass fuel usage and Standard of Living Index (SLI) were also collected from the study participants. A nested case-control study was carried out in this population. Cases are defined as bacteriological-positive cases diagnosed by either sputum smear or culture examination. For each case, five age- (within +/-5 years of age) and sex-matched controls were selected randomly from the non-cases residing in the same village/unit. Thus, 255 cases and 1275 controls were included in this study.

RESULTS

The unadjusted OR measured from univariate analysis for biomass fuel is 2.9 (95% CI 1.8 to 4.7). The adjusted OR measured from multivariate analysis using Cox regression is 1.7 (95% CI 1.0 to 2.9). Thirty-six percent of cases are attributable to biomass fuel usage.

CONCLUSION

The findings from this case-control study add to the evidence for an independent association between biomass smoke and pulmonary tuberculosis. Improvement in standards of living brought about by economic development will lead to more people using cleaner fuels for cooking than biomass fuel which in turn will lead to a reduction in the occurrence of pulmonary tuberculosis in the community.

Weight gain in patients with tuberculosis treated under directly observed treatment short-course (DOTS)

SET UP: One Tuberculosis Unit (TU) in Tiruvallur district, Tamil Nadu, India where Tuberculosis (TB) patients treated under Directly Observed Treatment Short Course (DOTS) programme.

OBJECTIVE

To identify the effects of weight gain among TB patients at the end of treatment on different factors such as socio-economic and demographic characteristics, smoking and drinking habits, treatment under supervision, the type of DOTS centres and problems in taking drugs.

METHODS

TB patients registered between May 1999 and December 2004 formed the study population. Multiple regression method was used for the analysis.

RESULTS

Among 1557 smear-positive TB patients registered under DOTS programme, the changes in weight ranged from a loss of 4 kgs to a gain of 20 kgs at the end of TB treatment; the average change in weight was 3.22 kgs. The gain in weight at the end of treatment was associated with age (<45 years), DOT at government centres, no problems in taking drugs as reported by patients and cure rate.

CONCLUSION

The findings showed that there is an association between gain in weight with DOT at government centres and cure of patients.

Annual risk of tuberculosis infection among tribal population of central India

OBJECTIVE

To estimate the annual risk of tuberculosis infection (ARTI) among tribal children of Madhya Pradesh, central India.

METHODS

Community-based, cross-sectional tuberculin survey among children aged 1-9 years in the tribal population of Madhya Pradesh. Multistage stratified cluster sampling was used to select a representative random sample of villages predominated by tribal population from selected districts. A total of 4802 children were tuberculin-tested with 1TU of PPD RT 23 and the reaction sizes read after 72 h.

RESULTS

A total of 3062 (64%) children had no BCG scar. The frequency distribution of children by reaction sizes indicated a fair mode at 18 mm in the right hand side of the distribution. By mirror-image technique, the prevalence of infection among children with no recognizable BCG scar was estimated as 6.8% (95% CI: 4.8-8.9%). The ARTI was computed as 1.3% (0.9-1.7%). The corresponding figures for children irrespective of scar status were 7.1% (95% CI: 5.5-8.8%) and 1.3% (1.0-1.7%) respectively.

CONCLUSIONS

The risk of tuberculosis infection in tribal population of Madhya Pradesh, central India is not different from other areas of the country. There is, however, a need to further intensify tuberculosis control measures on a sustained and long-term basis.

DOTS reaches socially marginalized population in the community: a study from a rural area of South India

We report here that the Directly Observed Treatment, Short course (DOTS) is reaching all tuberculosis patients in the community irrespective of social classification based on the analysis from the tuberculosis prevalence survey and programme performance during 1999-2003 from a rural area in Tamilnadu, South India. New smear- positive cases treated under a DOTS programme were classified in two groups namely; scheduled caste living in colony and other population. The prevalence of smear- positive cases among the scheduled caste population was 1.9 times higher than the other population and this was reflected in the notification also. The successful treatment outcome was also similar in these two groups (75% and 78% respectively; overall 77%). From these findings it is concluded that people living in colony have equal access to DOTS as those in the village.

Rapid decline in prevalence of pulmonary tuberculosis after DOTS implementation in a rural area of South India

SETTING

Tiruvallur District in Tamilnadu, South India, where the World Health Organization-recommended DOTS strategy was implemented as a tuberculosis (TB) control measure in 1999.

OBJECTIVE

To assess the epidemiological impact of the DOTS strategy on the prevalence of pulmonary tuberculosis (PTB).

DESIGN

Surveys of PTB were undertaken on representative population samples aged > or =15 years (n = 83000-90000), before and at 2.5 and 5 years after the implementation of the DOTS strategy. The prevalence of PTB (smear-positive/culture-positive) was estimated.

RESULTS

TB prevalence declined by about 50% in 5 years, from 609 to 311 per 100000 population for culture-positive TB and from 326 to 169/100000 for smear-positive TB. The annual rate of decline was 12.6% (95%CI 11.2-14.0) for culture-positive TB and 12.3% (95%CI 8.6-15.8) for smear-positive TB. The decline was similar at all ages and for both sexes.

CONCLUSION

With an efficient case detection programme and the DOTS strategy, it is feasible to bring about a substantial reduction in the burden of TB in the community.

Tuberculous infection in Saharia, a primitive tribal community of Central India

A cross-sectional tuberculin survey was carried out to estimate the prevalence of tuberculous infection and the annual risk of tuberculosis infection (ARTI) among children of Saharia, a primitive ethnic group in Madhya Pradesh, Central India. A total of 1341 children aged 1-9 years were subjected to tuberculin testing with 1 TU of PPD RT 23 and the reaction sizes were read after 72 h. The proportion of BCG scar-positive children was 34.6%. The frequency distribution of children by reaction sizes indicated a clear-cut anti-mode at 11 mm and a mode at 18 mm at the right-hand side of the distribution. The prevalence of infection among children irrespective of BCG scar was estimated as 20.4% (95% CI 18.2-22.5%) and the ARTI was 3.9% (95% CI 3.5-4.3%). The corresponding figures were 21.1% (95% CI 18.3-23.8%) and 3.9% (95% CI 3.4-4.5%) among BCG scar-negative children and 19.0% (95% CI 15.4-22.5%) and 4.0% (95% CI 3.2-4.8%) among BCG scar-positive children. The findings of the present study show a high prevalence of tuberculous infection and high ARTI in this primitive ethnic group. There is an urgent need to further intensify tuberculosis control measures on a sustained and long-term basis in this area.

Annual risk of tuberculosis infection in Chennai city

AIM

To study the proportion of children infected with Mycobacterium Tuberculosis in Chennai city.

METHODOLOGY

A cluster sampling methodology was adopted to select an estimated sample size of 7000 children from five corporation zones selected systematically from ten zones of the city. A total of 7098 children aged 1-9 years were subjected to Mantoux and test read; 1897 (27%) from slum area and 5201 (73%) from non-slum area.

RESULTS

The prevalence of infection among children without BCG scar was estimated to be 10.5 % (ARTI of 2.0%) and was similar to that among children irrespective of scar status. The prevalence of infection was higher among children in slum areas (11.1%; ARTI 2.1%) compared to non-slum areas (8.9%; ARTI 1.7%); but the difference was not statistically different.

CONCLUSION

The tuberculosis situation in Chennai as measured by risk of infection was higher in urban city area than rural areas and comparable to that found in other cities as reported from earlier studies. This information can be used as baseline information for monitoring the epidemiological trends in Chennai city in future.

Evaluation of different types of chest symptoms for diagnosing pulmonary tuberculosis cases in community surveys

BACKGROUND

Prevalence of tuberculosis (TB) is an important epidemiological index to measure the load of the disease in a community. A series of disease surveys were undertaken in rural community in Tiruvallur district in Tamilnadu, south India

OBJECTIVE

To investigate the yield of pulmonary tuberculosis (TB) cases by different symptoms status and suggest predominant symptoms for detection of cases in the community based surveys.

METHODS

Three disease surveys were conducted during 1999-2006, in a random sample of 82,000 adults aged > or = 15 years to estimate the prevalence and incidence of pulmonary TB. All subjects were screened for chest symptoms and chest radiography. Sputum examination was done among those who were either symptomatic or abnormal on X-ray or both. Cases observed through symptom inquiry were included for analysis.

RESULTS

In survey-I, 65.6% had cough of > or = 14 days and yielded 79.1% of the total cases. In surveys II and III, symptomatic subjects with cough contributed 69.5% and 69.2% of the cases respectively. In survey I, 26.8% had symptoms without cough but with at least chest pain > or = 1 month contributed 8.4% of total cases. The corresponding proportions in subsequent surveys were 29.3, 11.5%; and 23.4, 11.2% respectively. The number of symptomatics without cough and chest pain but with fever > or = 1 month was negligible.

CONCLUSION

The relative importance of cough as a predominant symptom was reiterated. The yield of pulmonary TB cases from symptomatics having fever of > or = 1 month was negligible. Fever may be excluded from the definition of symptomatics for screening the population in community surveys.

Survival of tuberculosis patients treated under DOTS in a rural Tuberculosis Unit (TU), south India

OBJECTIVE

To estimate survival probabilities and identify risk factors for death of tuberculosis (TB) patients during treatment period.

METHODS

TB patients registered during May 1999 to December 2004 from a rural TB unit (TU) with a population of 580,000 in Tiruvallur district, South India, formed study population. Life table and Cox's regression methods were used.

RESULTS

Of the 3818 TB patients who were initiated on treatment, 96, 94 and 97% of category--I, II and III respectively, were surviving after completion of treatment. Higher death rates were independently associated with patient's age (45 years), previous history of treatment, alcoholism and initial body weight (<35 kgs).

CONCLUSION

The survival probability was found to be similar in all patients irrespective of categorization. Necessary actions need to be initiated in the programme to improve body weight and abstain from alcoholism.

Excess mortality and risk factors for mortality among a cohort of TB patients from rural south India

OBJECTIVES

To estimate the excess general mortality among tuberculosis (TB) patients in a rural area (Tiruvallur) and identify risk factors for TB-related mortality.

SETTING

The study population consisted of all TB patients aged >or=15 years who were registered under the Revised National Tuberculosis Control Programme (RNTCP) during the years 2000 to 2003 at Velliyur TB unit (TU) in south India.

DESIGN

This is a retrospective cohort study of 3405 patients treated under the DOTS strategy, followed up from the date of start of treatment till the date of interview (for the survivors) or the date of death (for those who died).

RESULTS

There were 2710 (79.6%) survivors and 695 (20.4%) deaths. The excess general mortalities for the cohort, expressed as standardised mortality ratio (SMR), was 4.2 (95%CI 3.9-4.5). High SMR values were obtained for patients belonging to the 15-44 years age group (12.1), patients on Category II regimen (9.3), treatment failures (9.1) and defaulters (7.8). The adjusted hazards ratios (aHR) were high for patients aged 45-59 years (1.9), >or=60 years (3.1) and with incomplete treatment due to default or failure (6.4).

CONCLUSION

TB is one of the main causes of mortality in the younger age group. Among TB patients, the major risk factors for mortality are old age (>or=45 years) and incomplete treatment.

Impact of improved treatment success on the prevalence of TB in a rural community based on active surveillance

OBJECTIVE

To study the impact of improved treatment outcome of a cohort of patients treated under DOTS strategy on the prevalence of pulmonary tuberculosis (TB) in the community.

DESIGN

The data from TB register of one Tuberculosis Unit (TU) in Tiruvallur district of Tamilnadu, and two TB disease surveys conducted in the same area during 1999-2003 were analysed. The successful treatment outcome was compared to the prevalence of TB in the subsequent cohort.

RESULTS

The proportion of patients who completed treatment successfully was 75.3% in the first cohort period. This higher proportion of treatment success among patients treated under DOTS in the first cohort period (1999-2001) compared to the 51-55% reported during SCC, resulted in a lower prevalence of smear-positive cases, irrespective of culture results observed in the survey conducted during 2001-2003 compared to that in the survey conducted during 1999-2001 (252 vs. 323 per 100,000; annual decline of 9%). Similarly, a decline in culture-positive cases, irrespective of smear results, was also observed (443 vs. 605; annual decline 11%).

CONCLUSION

The higher proportion of successful completion of treatment after DOTS implementation was associated with a substantial decline in the prevalence of TB. These findings showed that we are in the direction towards achieving the Millennium Development Goals (MDGs).

Status of smear-positive TB patients at 2-3 years after initiation of treatment under a DOTS programme

OBJECTIVE

To describe the status of cases 2-3 years after the initiation of treatment under DOTS.

SETTING

After DOTS implementation in Tiruvallur district, south India, we followed up a cohort of smear-positive TB patients registered during 2002-03 after initiation of treatment.

RESULTS

The overall mortality rate was 15.0% and among the remaining 18.6% had active disease. In multivariate analysis, a higher mortality rate was independently associated with age, sex, occupation, treatment outcome and initial body weight of patients.

CONCLUSION

The mortality and morbidity rates are still high during follow-up and needs to be curtailed by addressing these issues effectively in TB control programme.

The prevalence of tuberculosis in different economic strata: a community survey from South India

A cross-sectional socio-economic survey to assess the standard of living index (SLI) of a rural population in South India was undertaken along with a tuberculosis (TB) prevalence survey during 2004-2006. Of 32,780 households, the SLI was low, medium and high in 22%, 36% and 42%, and TB prevalence was 343, 169 and 92 per 100,000 population, respectively, a significant decrease in trend (P < 0.001); 57% of the TB patients had a low SLI and the prevalence of TB was higher amongst the landless (P < 0.001), those living below the poverty line (P < 0.01) and in katcha houses (P < 0.001), suggesting that TB disproportionately affects those with a low SLI.

Selected biological and behavioural risk factors associated with pulmonary tuberculosis

OBJECTIVES

To measure the independent association of risk factors age, sex, smoking and alcoholism with pulmonary tuberculosis (TB) in terms of prevalence odds ratio (POR).

METHOD

A community-based cross-sectional survey was conducted from June 2001 to December 2003. A total of 93945 individuals aged > or = 15 years selected from a random sample of villages in a district from South India were screened for pulmonary TB by chest symptoms and chest X-ray (MMR). Two sputum samples were collected (one spot and one early morning) from patients with chest symptoms and those with abnormal X-rays for examination by microscopy for acid-fast bacilli and by culture for Mycobacterium tuberculosis. Bacillary cases are bacteriologically positive cases diagnosed by either sputum smear or culture examination. In addition, data on exposure to tobacco smoking and alcohol consumption were collected from the male population only. All females were considered non-smokers and non-alcoholics.

RESULTS

A total of 429 bacteriologically positive cases were detected during the survey. The adjusted PORs (with 95%CI) for age, sex, smoking and alcoholism were 3.3 (2.7-4.1), 2.5 (1.9-3.3), 2.1 (1.7-2.7) and 1.5 (1.2-2.0), respectively.

CONCLUSION

Risk factors such as age, sex, smoking and alcoholism are independently associated with pulmonary TB. Risk factors age and sex show a stronger association than smoking and alcoholism.

Additional risk of developing TB for household members with a TB case at home at intake: a 15-year study

OBJECTIVE

To assess the additional risk to household contacts from an infectious case of tuberculosis (TB) at home in a rural community in south India.

METHODS

In all, 3506 contacts of smear-positive (S+C+) and 2910 contacts of smear-negative TB cases (S-C+) and 246 845 persons with no TB case at home were followed for 15 years, with a repeat survey every 2.5 years consisting of radiographic and sputum examination, selective follow-up of high-risk individuals and passive surveillance. If a case developed during follow-up, all household members were subsequently considered as contacts. Cox's proportional hazards model (multivariate) was employed to compare incidences.

RESULTS

The annual incidence of culture-positive TB was respectively 526 and 271 per 100000 population for contacts of smear-positive and smear-negative patients, and 198/100000 in non-contacts. The adjusted hazard rate was 3.4 for contacts of smear-positive patients (95% CI 3.0-3.9) and 1.7 for contacts of smear-negative patients (95% CI 1.4-2.0) as compared to non-contacts. Of 3942 incident cases, 337 (8.5%) came from households with a TB case.

CONCLUSION

Although family contacts had a significantly higher incidence, their contribution to total new caseload was meagre. Contact chemoprophylaxis as a public health measure would therefore have limited impact on community TB incidence.

Status of re-registered patients for tuberculosis treatment under DOTS programme

OBJECTIVE

To assess the proportion of patients re-registered after default, failure or successful treatment, completion and evaluate their treatment outcome.

SETTING

Tuberculosis patients diagnosed were registered for treatment under DOTS in rural area, South India. Patients reregistered during 1999-2004 identified from the TB register were considered for analysis.

RESULTS

Among 273 Category-I patients 'defaulted' 23% and among 112 'failure' cases 68% were re-registered. After 'successful treatment completion' of 1796 cases 6.5% were re-registered as relapse. Corresponding figures for Category II were 20% of 281 defaulters; 23% of 60 failures; 12.9% of 302 'successful treatment completion' patients. Among patients re-registered as 'default', subsequent default was also high (57% vs 37%). Failure in Category II treatment was similar among patients who were re-registered for Category II and initially registered in it for treatment. Median delay for reregistration was >200 days for 'defaulters' and 18 days for 'failures'.

CONCLUSION

Our findings emphasise the need for continuing motivation and prompt defaulter retrieval action to reduce default at all stages of treatment. 'Defaulters' need to be contacted so that they can be started on treatment without delay. Patients declared as 'successful treatment completion' should be encouraged to report if chest symptoms recur.

Active community surveillance of the impact of different tuberculosis control measures, Tiruvallur, South India, 1968-2001

BACKGROUND

Tuberculosis is curable, but community surveys documenting epidemiological impact of the WHO-recommended DOTS strategy on tuberculosis prevalence have not been published. We used active community surveillance to compare the impact of DOTS with earlier programmes.

METHODS

We conducted tuberculosis disease surveys using random cluster sampling of a rural population in South India approximately every 2.5 years from 1968 to 1986, using radiography as a screening tool for sputum examination. In 1999, DOTS was implemented in the area. Prevalence surveys using radiography and symptom screening were conducted at the start of DOTS implementation and after 2.5 years.

RESULTS

From 1968 to 1999, culture-positive and smear-positive tuberculosis declined by 2.3 and 2.5% per annum compared with 11.9 and 5.6% after DOTS implementation. The 2.5 year period of DOTS implementation accounted for one-fourth of the decline in prevalence of culture-positive tuberculosis over 33 years. Multivariate analysis showed that prevalence of culture-positive tuberculosis decreased substantially (10.0% per annum, 95% CI: 2.8-16.6%) owing to DOTS after only slight declines related to temporal trends (2.1% annual decline, 95% CI: 1.1-3.2%) and short-course chemotherapy (1.5% annual decline, 95% CI: -9.7% to 11.5%). Under DOTS, the proportion of total cases identified through clinical care increased from 81 to 92%.

CONCLUSIONS

Following DOTS implementation, prevalence of culture-positive tuberculosis decreased rapidly following a gradual decline for the previous 30 years. In the absence of a large HIV epidemic and with relatively low levels of rifampicin resistance, DOTS was associated with rapid reduction of tuberculosis prevalence.

Mortality of tuberculosis patients in Chennai, India

OBJECTIVE

We aimed to measure the mortality rate and excess general mortality as well as identify groups at high risk for mortality among a cohort of tuberculosis patients treated in Chennai Corporation clinics in south India.

METHODS

In this retrospective cohort study we followed up 2674 patients (1800 males and 874 females) who were registered and treated under the DOTS strategy in Chennai Corporation clinics in 2000. The follow-up period from the date of start of treatment to either the date of interview, or death was 600 days.

FINDINGS

The mortality rate among this cohort of tuberculosis patients was 60/1000 person-years. The excess general mortality expressed as standardized mortality ratio (SMR) was 6.1 (95% confidence interval (CI)=5.4-6.9). Younger patients, men, patients with Category II disease, patients who defaulted on, or failed courses of treatment, and male smokers who were alcoholics, all had higher mortality ratios when compared to the rest of the cohort.

CONCLUSION

The excess mortality in this cohort was six times more than that in the general population. Young age, male sex, smear-positivity, treatment default, treatment failure and the combination of smoking and alcoholism were identified as risk factors for tuberculosis mortality. We suggest that mortality rate and excess mortality be routinely used as a monitoring tool for evaluating the efficiency of the national control programme.

Impact of BCG vaccination on tuberculin surveys to estimate the annual risk of tuberculosis infection in south India

BACKGROUND AND OBJECTIVES

Annual risk of tuberculosis infection (ARTI) computed from prevalence of infection measures the extent of tuberculosis transmission in the community and it is used to monitor the tuberculosis control programme. This is usually derived from tuberculin surveys among children not vaccinated with BCG. This study explores whether the estimated ARTI among BCG vaccinated children is comparable to that of unvaccinated children.

METHODS

Three tuberculin surveys were undertaken among children aged >10 yr as part of assessing the impact of DOTS implemented in Tiruvallur district, south India. The prevalence of infection was estimated using the anti-mode method among vaccinated and unvaccinated children. The ARTI was computed separately and compared in all the three surveys.

RESULTS

The prevalence of infection among unvaccinated and vaccinated children in the first survey were 7.8 per cent (95% CI: 7.1-8.6) and 7.9 per cent (95% CI: 7.1-8.8) respectively (ARTI was estimated to be 1.6 per cent in both groups) and the difference was not statistically significant. The corresponding figures for children test read in the second and third surveys were 6.9 per cent (95% CI: 6.2-7.6) and 6.8 per cent (6.0-7.5) and; 6.0 per cent (5.2-6.7) and 6.0 per cent (5.5-6.5) respectively. The computed ARTI was respectively 1.4 and 1.2 per cent among unvaccinated children in the second and third surveys; and 1.4 and 1.2 per cent among vaccinated children in the second and third rounds.

INTERPRETATION AND CONCLUSION

There was no difference in the infection with Mycobacterium tuberculosis among vaccinated and unvaccinated children. BCG vaccinated children may thus be included for estimation of infection to assess the extent of transmission in the community as well as for monitoring purpose.

Association of conversion & cure with initial smear grading among new smear positive pulmonary tuberculosis patients treated with Category I regimen

BACKGROUND & OBJECTIVES

Early diagnosis of tuberculosis (TB) is important for initiating treatment to gain cure. The present investigation was undertaken to study the association of conversion and cure with initial smear grading among pulmonary tuberculosis (TB) patients registered in a directly observed treatment - short course (DOTS) programme in Tiruvallur district, south India.

METHODS

All new smear positive cases registered from May, 1999 to December, 2002 were analysed for conversion and cure related to initial smear grading.

RESULTS

Of the 1463 patients, 1206(82.4%) were converted at the end of the intensive phase and 1109 (75.8%) were declared 'cured' after the completion of treatment. The cure rate decreased as the initial smear grading increased and the decrease in trend was statistically significant (P=0.01). Similarly, a significant decrease in conversion rate was also observed with increase in initial smear grading (P<0.001). In multivariate analysis, lower cure rate was significantly associated with patient's age (AOR=1.5, 95% CI=1.1-2.1), alcoholism (AOR=1.7, 95% CI 1.2- 2.4) and conversion at the end of intensive phase (AOR=3.5, 95% CI= 2.6-4.8).

INTERPRETATION & CONCLUSION

Cure and conversion rates were linearly associated with initial smear grading. High default and death rates were responsible for low cure and conversion. The proportion of patients who required extension of treatment and those who had an unfavourable treatment outcome were significantly higher among patients with a 3+ initial smear grading. This reiterates the need to pay more attention in motivating these patients to return to regular treatment and sustained commitment in the control of tuberculosis. There is a need to extend the treatment for one more month in the intensive phase of treatment.

Coincident filarial, intestinal helminth, and mycobacterial infection: helminths fail to influence tuberculin reactivity, but BCG influences hookworm prevalence

The prevalence of helminth and tuberculosis infections is high in South India, whereas Bacille-Calmette-Guerin (BCG) vaccine efficacy is low. Our aim was to determine whether concurrent helminth infection alters the ability to mount a delayed-type hypersensitivity response to tuberculin. In a cross-sectional study in southern India, individuals 6-65 years of age were screened for intestinal helminths, circulating filarial antigenemia, tuberculin reactivity, active tuberculosis, and history of BCG vaccination; 54% were purified protein derivative (PPD) positive, 32% had intestinal helminth infection, 9% were circulating filarial antigen positive, and 0.5% had culture-confirmed active tuberculosis. Only age and BCG vaccination were significantly associated with PPD reactivity; however, BCG vaccination was associated with a lower prevalence of hookworm infection relative to those without prior BCG vaccination. Neither intestinal helminth infection nor filarial infection was associated with diminished frequencies of PPD positivity. Our findings suggest that preceding helminth infection does not influence significantly the delayed-type hypersensitivity response to tuberculin.

Status of bacillary tuberculosis cases identified in a community survey under different control programmes

We report the status of bacillary tuberculosis (TB) cases identified in community surveys undertaken at 2.5-year intervals. We observed three cohort periods to represent the different TB control programmes, namely 12-18 months of treatment (pre-short-course chemotherapy [pre-SCC]), 6-8 months SCC and DOTS in the area. There was a significant reduction in deaths from 23% to 17%, and an increase in the proportion of cases negative by smear and/or culture for Mycobacterium tuberculosis, from 54% to 58% in the pre-SCC and SCC cohorts to 80% in the DOTS cohort. These findings suggest that the DOTS strategy could have a significant influence on TB epidemiology.

Yield of pulmonary tuberculosis cases by employing two screening methods in a community survey

OBJECTIVE

To compare the yield of tuberculosis (TB) cases by two screening methods.

SETTING

Two disease surveys conducted in Tiruvallur, south India.

RESULTS

Of bacteriologically confirmed cases, 60% were identified by symptom inquiry alone whereas 82% were identified using chest radiography (CXR).

CONCLUSION

The prevalence of TB was underestimated by both methods. The total cases in this community can be estimated by multiplying the number of identified cases by a correction factor (CF) of 1.7 when symptom inquiry alone is used or 1.2 when CXR is used. The CF may be different in other settings.

Trend in the prevalence of TB infection and ARTI after implementation of a DOTS programme in south India

OBJECTIVE

To estimate the risk of tuberculosis (TB) infection among children <10 years and assess the impact of a DOTS-based programme.

SETTING

After DOTS implementation in Tiruvallur district, south India, we undertook three tuberculin surveys and estimated the ARTI among children aged <10 years.

RESULTS

The ARTI estimates in the three tuberculin surveys were 1.6%, 1.4% and 1.2%, respectively. There was a significant decline in the trend of TB infection (P < 0.001). The annual decline estimated from the first to the third survey was 6%.

CONCLUSION

DOTS implementation was associated with a substantial reduction in the risk of TB infection among children.

Relationship of ARTI to incidence and prevalence of tuberculosis in a district of south India

OBJECTIVE

To validate the currently used empirical relationship between annual risk of tuberculous infection (ARTI) and incidence and prevalence of smear-positive cases.

SETTING

Two disease surveys to estimate the prevalence and incidence of tuberculosis (TB) among adults in Tiruvallur district, south India, and a tuberculin survey to estimate the ARTI among children.

RESULTS

The incidence of TB was estimated to be 82 and prevalence 210 per 100,000 population and ARTI 1.6%. We estimated that 1% ARTI corresponded to 51 new and 131 prevalent cases.

CONCLUSION

The currently used empirical relationship between ARTI and incidence can be used by programme managers as an effective monitoring tool.

Initial drug susceptibility profile of M. tuberculosis among patients under TB programme in South India

SETTING

Pulmonary tuberculosis (PTB) patients enrolled for treatment at government health facilities in a sub-district of Thiruvallur district, Tamil Nadu, India.

OBJECTIVES

To determine the drug susceptibility profile among PTB patients admitted to treatment according to the Revised National Tuberculosis Control Programme (RNTCP).

METHODOLOGY

From May 1999 to December 2003, two additional sputum samples were collected from all patients at the start of anti-tuberculosis treatment under DOTS and were transported to a central laboratory for Mycobacterium tuberculosis culture and drug susceptibility testing (DST).

RESULTS

DST results were available for 1603 new sputum smear-positive patients; 85% of patients had organisms fully susceptible to streptomycin (S), isoniazid (H) and rifampicin (R), 10.4% any resistance to H and 1.7% to HR. Of 443 patients with history of previous anti-tuberculosis treatment, 59% had organisms susceptible to S, H and R, 37% had any resistance to H and 11.7% to HR.

CONCLUSION

The DST profile showed that the vast majority of patients have drug-susceptible organisms, and that currently recommended regimens under the RNTCP would be effective in the treatment of TB.

Value of dual testing for identifying tuberculous infection

SETTING

A rural community in Chingleput district in Tamil Nadu state in south India.

OBJECTIVE

To determine the value of dual testing with PPD-S and PPD-B for identifying subjects with a tuberculous infection.

DESIGN

About 240,000 subjects in rural south India, all of whom were tested initially with PPD-S and PPD-B, were followed up for 15 years, mainly by total population survey once in every 212 years. The incidence of culture-positive tuberculosis was estimated using life-table technique.

RESULTS

Among 17,530 subjects with an intermediate reaction (8-11 mm) to PPD-S at intake, 285 with an induration to PPD-S exceeding the induration to PPD-B by at least 2mm, had a significantly higher incidence of culture-positive tuberculosis than the remaining (154 and 93 per 100,000), and similarly 481 who had an induration of <10mm to PPD-B compared to those with >or=10 mm (131 and 93 per 100,000). These subjects may be regarded as having a tuberculous infection. Infection with non-tuberculous mycobacteria conferred protection of about 30% against the development of tuberculosis over a 15-year period.

CONCLUSION

In subjects with an intermediate reaction (8-11 mm) to PPD-S, dual testing with PPD-B enabled identification of those with a tuberculous infection. Most of the reactions were due to non-tuberculous mycobacteria.

Estimation of burden of tuberculosis in India for the year 2000

BACKGROUND AND OBJECTIVE

Data on the burden of tuberculosis (TB) in India are vital for programme planners to plan the resource requirements and for monitoring the nation-wide TB control programme. There was a need to revise the earlier estimate on the burden of TB in India based on the increase in population and current epidemiological data. This study estimates the burden of disease for the year 2000 based on recent prevalence of TB and annual risk of tuberculosis infection (ARTI) estimates.

METHODS

Data on prevalence generated among adults by the Tuberculosis Research Centre (TRC), Chennai, among children by National Tuberculosis Institute (NTI), Bangalore, and the ARTI estimates from the nation-wide sample survey by NTI and TRC were used for the estimation. The prevalence of disease corresponding to 1 per cent ARTI was extrapolated to different parts of the country using the estimates of ARTI and the population in those areas and added together to get the total cases. Abacillary cases that required treatment were estimated from X-ray abnormals. The estimates of bacillary, abacillary and extrapulmonary cases were then combined to get the national burden.

RESULTS

The estimated number of bacillary cases was 3.8 million (95% CI: 2.8-4.7). The number of abacillary cases was estimated to be 3.9 million and that for extrapulmonary cases was 0.8 million giving a total burden of 8.5 million (95% CI: 6.3-10.4) for 2000.

INTERPRETATION AND CONCLUSION

The present estimate differs from the earlier estimates because we have included the disease burden of X-ray cases that are likely to breakdown to bacillary cases in a one year period, and extrapulmonary TB cases. The current estimates provided baseline information for advocacy and planning resource allocation for TB control activities. Also, these estimates can be compared with that in future years to measure the long term impact of TB control activities in India.

Predictors of relapse among pulmonary tuberculosis patients treated in a DOTS programme in South India

OBJECTIVE

To identify risk factors associated with relapse among cured tuberculosis (TB) patients in a DOTS programme in South India.

DESIGN

Sputum samples collected from a cohort of TB patients registered between April 2000 and December 2001 were examined by fluorescence microscopy for acid-fast bacilli and by culture for Mycobacterium tuberculosis at 6, 12 and 18 months after treatment completion.

RESULTS

Of the 534 cured patients, 503 (94%) were followed up for 18 months after treatment completion. Of these, 62 (12%) relapsed during the 18-month period; 48 (77%) of the 62 relapses occurred during the first 6 months of follow-up. Patients who took treatment irregularly were twice more likely to have a relapse than adherent patients (20% vs. 9%; adjusted odds ratio [aOR] 2.5; 95% CI 1.4-4.6). Other independent predictors of relapse were initial drug resistance to isoniazid and/or rifampicin (aOR 4.8; 95% CI 2.0-11.6) and smoking (aOR 3.1; 95% CI 1.6-6.0). The relapse rate among non-smoking, treatment adherent patients with drug-sensitive organisms was 4.8%.

CONCLUSIONS

The relapse rate under the DOTS programme may be reduced by ensuring that patients take their treatment regularly and are counselled effectively about quitting smoking.

Comparison of cough of 2 and 3 weeks to improve detection of smear-positive tuberculosis cases among out-patients in India

SETTING

Governmental health facilities in six districts of India.

OBJECTIVE

To estimate the prevalence of cough and to compare the detection of smear-positive tuberculosis (TB) among out-patients with cough of > or =2 or > or =3 weeks.

DESIGN

Trained health workers questioned each out-patient for presence of cough. Those with cough > or =2 weeks underwent sputum microscopy.

RESULTS

Of 55561 out-patients interviewed, 2210 (4%) had cough > or =2 weeks, of whom 267 had sputum-positive TB, compared to 182/1370 with cough > or =3 weeks. The 31% who did not spontaneously complain of cough were less likely to be sputum-positive than those who did (45/680 [7%] vs. 222/1530 [15%], P < 0.001), but they accounted for 45/267 smear-positive cases. Using cough > or =2 weeks as the screening criterion, the estimated number of smears performed per day at each primary and secondary health care facility was respectively 8 and 19, compared to 5 and 12 using cough > or =3 weeks.

CONCLUSION

The detection of smear-positive TB cases can be substantially improved by actively eliciting history of cough from all out-patients, and by changing the screening criterion for performing sputum microscopy among out-patients from cough > or =3 weeks to > or =2 weeks. Before implementing this change nationally, its programmatic feasibility should be assessed.

Smear examination of two specimens for diagnosis of pulmonary tuberculosis in Tiruvallur District, south India

SETTINGS

A general hospital and three peripheral health institutions (PHI) in Tiruvallur District, south India.

OBJECTIVE

To validate the case detection strategy for diagnosis of pulmonary tuberculosis by smear microscopy of two sputum specimens versus three.

METHODS

In the Revised National Tuberculosis Control Programme (RNTCP), three smears from every symptomatic patient attending the PHI were examined for acid-fast bacilli (AFB) by Ziehl-Neelsen (ZN) microscopy. The data from the Tuberculosis Laboratory Registers from the above centres were analysed.

RESULTS

Of 7843 chest symptomatics who had provided three sputum specimens for examination, 895 (11.4%) were smear-positive on at least two specimens. Examination of two specimens--first spot and early morning specimens (837, 93.5%) or early morning and second spot specimens (843, 94.2%)--yielded the highest number of cases.

CONCLUSION

The examination of two sputum smears (one spot and an early morning) is as effective as examination of three smears.

Estimation of annual risk of tuberculosis infection (ARTI) among children aged 1-9 years in the south zone of India

OBJECTIVE

To estimate the annual risk of tuberculosis infection (ARTI) among children aged 1-9 years in the south zone of India.

SETTING

The survey was carried out in a representative sample of villages and census enumeration blocks of towns in four south Indian states, as a part of a nationwide tuberculin survey.

DESIGN

Six districts were selected through systematic random sampling. Four hundred and twenty rural clusters and 180 urban clusters were selected from these districts on the basis of the rural-urban ratio in the entire zone. To obtain the required sample of 12,000 children without bacille Calmette-Guérin (BCG) vaccination, 51,000 had to be covered. Eighty-five children from each cluster were tuberculin tested and read for reaction sizes. The ARTI was computed from the estimated prevalence of TB infection among children without a BCG scar.

RESULT

Among 52,951 children registered for the study, 50,846 (96%) had a tuberculin test result. The BCG coverage for the study population was about 65%. Among 17,811 children without a BCG scar, the prevalence of infection was 5.9% (95%CI 4.0-7.7%); the corresponding ARTI was 1.0% (95%CI 0.7-1.4%) [correction].

CONCLUSION

The estimated ARTI for the south zone is 1.0%, as compared to the national average of 1.7% used for programme evaluation. This baseline information should be useful for the assessment of future trends.

Gender disparities in tuberculosis: report from a rural DOTS programme in south India

SETTING

Tiruvallur District, south India.

OBJECTIVES

To examine gender differences in tuberculosis among adults aged >14 years with respect to infection and disease prevalence, health care service access, care seeking behaviour, diagnostic delay, convenience of directly observed treatment (DOT), stigma and treatment adherence.

METHODS

Data were collected from 1) community survey, 2) self-referred out-patients seeking care at governmental primary health institutions (PHIs), 3) tuberculosis suspects referred for sputum microscopy at PHIs, and 4) tuberculosis patients notified under DOTS. Community survey results were compared with those for patients notified at PHIs.

RESULTS

In the community, 66% of males and 57% of females had tuberculosis infection. The prevalence of smear-positive tuberculosis was 568 and 87/100,000, respectively, among males and females. Fewer males than females attended PHIs (68 men for every 100 women). Females constituted 13% of all smear-positive patients detected in the community survey, and 20% of those detected at PHIs (P < 0.05). The probability of notification decreased significantly with age among both males and females. Significantly more females than males felt inhibited discussing their illness with family (21% vs. 14%) and needed to be accompanied for DOT (11% vs. 6%). Males had twice the risk of treatment default than females (19% vs. 8%; P < 0.01).

CONCLUSIONS

Despite facing greater stigma and inconvenience, women were more likely than men to access health services, be notified under DOTS and adhere to treatment. Men and elderly patients need additional support to access diagnostic and DOT services.

A baseline survey of the prevalence of tuberculosis in a community in south India at the commencement of a DOTS programme

OBJECTIVE

To determine the baseline prevalence of culture-positive and smear-positive tuberculosis and the annual risk of tuberculous infection (ARTI) in a community in south India where DOTS is being implemented.

METHODS

Using cluster sampling, 50 rural panchayats (villages) and three urban units in Tiruvallur district were selected randomly. All adults aged > or = 15 years underwent symptom and radiographic examination, and those with abnormal shadows and/or chest symptoms had sputum smear and culture examination. In another cluster sample of 73 villages and three urban units, all children aged < 10 years were tuberculin tested.

RESULTS

The prevalence of culture-positive and smear-positive tuberculosis was respectively 605 and 323/100,000. Both increased appreciably with age, and were substantially higher in males than in females at all ages; the overall male:female ratio was 5.5 for culture-positive and 6.5 for smear-positive tuberculosis. The ARTI in children aged under 10 years was 1.6%, and was unaffected by sex. Over three decades there was an overall decline of 1.8% per annum in the prevalence of culture-positive and 2.1% for smear-positive tuberculosis.

CONCLUSION

Tuberculosis is a major problem in this rural community in south India, with a prevalence of 605/100,000 for culture-positive tuberculosis and 323/100,000 for smear-positive tuberculosis.

Association of initial tuberculin sensitivity, age and sex with the incidence of tuberculosis in south India: a 15-year follow-up

OBJECTIVE

To determine the association of initial tuberculin sensitivity, age and sex with the development of tuberculosis.

METHODS

A 15-year follow-up of 280000 subjects in south India, where new cases of tuberculosis were detected mainly by periodic population surveys. Life-table technique was employed to estimate tuberculosis incidence and disease risk in survivors. The independent effect of tuberculin sensitivity, sex and age at intake was determined using Cox's proportional hazard model.

RESULTS

Taking subjects with reaction size 0-7 mm to 3 IU PPD-S as reference group, the adjusted relative risk (RR) for developing culture-positive tuberculosis was 1.1, 1.9, 2.9, 3.6 and 3.3 for those with indurations of 8-11, 12-15, 16-19, 20-24 and > or = 25 mm (P < 0.01). Considering subjects aged 0-4 years as reference group, the adjusted RR for the other groups increased from 1.7 to 10.8 (P < 0.01). Males had a substantially higher incidence (adjusted RR 3.0, P < 0.001). The risk of culture-positive tuberculosis over 15 years in survivors was 3.3% (5.0% in males and 1.6% in females), and increased substantially with tuberculin sensitivity at intake. In those with > or = 12 mm at intake, the approximate lifetime risk was 6.1% (8.6% in males and 3.1% in females).

CONCLUSION

The incidence of tuberculosis increased steadily with tuberculin sensitivity to PPD-S and age at intake. Males had a significantly higher risk than females in every PPD-S group and the overall risk was three-fold higher.

Seroprevalence of human immunodeficiency virus (HIV) infection among tuberculosis patients in Tamil Nadu

BACKGROUND & OBJECTIVES

The dual epidemic of HIV and tuberculosis is a cause for concern in those countries where these two infections are prevalent in epidemic proportions. We undertook a survey at two sites in North Arcot district of Tamil Nadu in 1992-1993, to know the seroprevalence of HIV infection among tuberculosis patients. The objective of this study was to re-examine the prevalence of HIV infection among tuberculosis patients in a repeat survey.

METHODS

The study was undertaken in four centres: District Tuberculosis Centre (DTC), Vellore, Tuberculosis Sanatorium, Pennathur (Vellore), District TB Centre (DTC), Kancheepuram and the Government Thiruvotteswarar Tuberculosis Hospital (GTTH), Chennai in the northern part of Tamil Nadu during 1997-1998. A total of 2361 newly diagnosed TB patients were registered in this study. HIV serology after pre-test counseling was done along with sputum examination for acid-fast bacillus by smear and culture for mycobacteria for all patients.

RESULTS

The overall HIV seroprevalence among TB patients was 4.7 per cent. The highest HIV seropositivity rate was found among patients aged 30-39 yr (10.6%). HIV seroprevalence showed a wide variation among the different centres ranging from 0.6. per cent in DTC, Kancheepuram to 9.4 per cent in Pennathur Sanatorium, Vellore. Sputum smear positivity was 88 per cent among the HIV-negative and 83 per cent among HIV-positive tuberculosis patients.

INTERPRETATION & CONCLUSION

HIV infection is on the rise among TB patients in Tamil Nadu. Acid-fast smear microscopy is adequate for the diagnosis of pulmonary tuberculosis, and drug resistance among HIV positive patients is not a major problem at this point of time; hence antituberculosis regimens recommended by the Revised National Tuberculosis Control Program (RNTCP) can be used to treat HIV positive patients with tuberculosis.

Are community surveys to detect tuberculosis in high prevalence areas useful? Results of a comparative study from Tiruvallur District, South India

BACKGROUND

In Tiruvallur District, South India, tuberculosis cases are detected at health facilities (HF) as part of a DOTS programme, and by screening adults through community survey (CS) as part of ongoing epidemiological research.

OBJECTIVE

To compare socio-demographic, clinical and bacteriological characteristics and treatment outcomes of all patients detected at HF with those of all patients detected by CS during a 12-month period.

RESULTS

Of 32,663 adults surveyed, 100 had smear-positive and 116 had smear-negative tuberculosis; of 65 smear-positive patients who began treatment, 44 were cured. Compared to HF patients, CS patients were significantly more likely to be older (AOR = 1.9), male (AOR = 2.7), non-literate (AOR = 1.7), and living in poor quality housing (AOR = 2.0), and were less likely to have cough >3 weeks (AOR = 3.4) or smear-positive tuberculosis (AOR = 4.2). Of 61 new smear-positive CS patients, 40 reported chest symptoms; of these, 32 (80%) had already consulted a health-care provider, but remained undiagnosed.

CONCLUSIONS

The community survey was of little value in tuberculosis case detection even in this high-prevalence setting. Patients identified by the survey were less symptomatic and less infectious, and less than half were cured. Diagnostic services should be made more accessible to the elderly, the non-literate and men.

Risk factors associated with default, failure and death among tuberculosis patients treated in a DOTS programme in Tiruvallur District, South India, 2000

OBJECTIVE

To identify risk factors associated with default, failure and death among tuberculosis patients treated in a newly implemented DOTS programme in South India.

DESIGN

Analysis of all patients registered from May 1999 through April 2000. A community survey for active tuberculosis was underway in the area; patients identified in the community survey were also treated in this programme.

RESULTS

In all, 676 patients were registered during the period of the study. Among new smear-positive patients (n = 295), 74% were cured, 17% defaulted, 5% died and 4% failed treatment. In multivariate analysis (n = 676), higher default rates were associated with irregular treatment (adjusted odds ratio [AOR] 4.3; 95%CI 2.5-7.4), being male (AOR 3.4; 95%CI 1.5-8.2), history of previous treatment (AOR 2.8; 95%CI 1.6-4.9), alcoholism (AOR 2.2; 95%CI 1.3-3.6), and diagnosis by community survey (AOR 2.1; 95%CI 1.2-3.6). Patients with multidrug-resistant tuberculosis (MDR-TB) were more likely to fail treatment (33% vs. 3%; P < 0.001). More than half of the patients receiving Category II treatment who remained sputum-positive after 3 or 4 months of treatment had MDR-TB, and a large proportion of these patients failed treatment. Higher death rates were independently associated with weight <35 kg (AOR 3.8; 95%CI 1.9-7.8) and history of previous treatment (AOR 3.3; 95%CI 1.5-7.0).

CONCLUSIONS

During this first year of DOTS implementation with sub-optimal performance, high rates of default and death were responsible for low cure rates. Male patients and those with alcoholism were at increased risk of default, as were patients identified by community survey. To prevent default, directly observed treatment should be made more convenient for patients. To reduce mortality, the possible role of nutritional interventions should be explored among underweight patients.

Trends in the prevalence and incidence of tuberculosis in south India

OBJECTIVE

To study trends in the prevalence and incidence of tuberculosis in south India.

METHODS

In 1968-1970, about 100,000 subjects were surveyed for tuberculosis and followed thereafter for 15 years, mainly by repeat survey once every 2.5 years. New entrants were inducted at every repeat survey. Radiographic examination of subjects aged 5 years or more and sputum smear and culture examinations of those with an abnormal shadow were undertaken; tuberculin tests were done initially on all, and at 4, 10 and 15 years in selected samples of those aged 1-9 years.

RESULTS

The prevalence of culture-positive tuberculosis decreased by 1.4% per annum to 694/100,000, while that of smear-positive tuberculosis showed no significant decrease from 457/100,000. The annual incidence of culture-positive tuberculosis decreased by 4.3%/annum to 189/100,000 and that of smear-positive tuberculosis decreased by 2.3%/annum to 113/100,000. Decreases in incidence occurred exclusively in those with abnormal radiographic findings suggestive of tuberculosis at the start of the period. The annual risk of tuberculosis infection (ARTI) was initially 2%, and showed no sign of decline over the period.

CONCLUSION

The prevalence of tuberculosis and ARTI showed little or no decrease over the 15-year period. A significant decrease in incidence occurred, but exclusively in those with abnormal radiograph suggestive of tuberculosis at the start of the period.