Occupational exposure of vehicular emissions and cardiorespiratory risk among urban metropolitan bus drivers: A cross-sectional comparative study.

BACKGROUND: Vehicular emissions on long-term exposure predispose metropolitan bus drivers to cardiorespiratory ailments. OBJECTIVE: To evaluate the cardiorespiratory risk of urban metropolitan bus drivers related to vehicular emission exposure. METHODS: Bus drivers (with service >5 years, n = 254) and their administrative controls (primarily engaged in indoor white collared jobs, n = 73) were recruited. Demographic, occupational and clinical details were collected through pre-validated standardized format. Pulmonary Function Test (PFT) and lipid profile were carried out with standard protocol. Risk for cardiovascular events for preceding 10-years was estimated with WHO/ISH risk prediction chart and QRISK3 score. Exposure assessments for particulate matter (PM) were performed for both groups while duty hours. RESULTS: Exposure of drivers to PM2.5 six times and PM10 five times higher in comparison to administration staff (PM2.5- 970.9 v/s 145.0µg/m3 TWA and PM10- 1111.7 v/s 233.8µg/m3 TWA). Bus drivers exhibited significantly higher prevalence of respiratory symptoms (dyspnea-25% v/s 6.8% and cough-20.1% v/s 9.8%) and compromised PFT (obstructive-21% v/s 5.7% and restrictive-4.2% v/s 2.9%) in comparison to controls. Multivariate regression statistics reveal a significant decline for FEV1/FVC and FEV25-75 % among bus drivers compared to controls, controlling the influence of physiological and environmental factors. The difference between predicted cardiac age and their respective chronological age was twice higher (8.3 v/s 4.3 years) among drivers compared to their administration staff. CONCLUSION: Bus drivers were exposed to high levels of outdoor air pollutants. Further, the drivers exhibited higher risk for ischemic attack and obstructive airway diseases as compared to administration staff.

Occupational lead exposure is an independent modulator of hypertension and poor pulmonary function: A cross-sectional comparative study in lead-acid battery recycling workers.

Blood lead level (BLL) is the primary biomarker for lead-exposure monitoring in occupationally exposed workers. We evaluated occupational lead-exposure (OE) impact on cardiopulmonary functions in lead-acid battery recycling unit workers. Seventy-six OE cases and 30 control subjects were enrolled for questionnaire-based socio-demographic, dietary, tobacco usage, and medical history data. Anthropometric measurements, systolic and diastolic blood pressure (SBP and DBP), and pulmonary function tests were performed. Venous blood was collected for BLL, hematological analysis, and biochemical analysis. OE caused a significant increase in BLL, SBP, DBP, and small airways obstruction in lung function tests. It also impaired platelet indices, affected renal and liver biochemical measurements, and promoted oxidative stress and DNA damage. Multilinear regression analysis suggested that BLL affected SBP (ß = 0.314, p = .034) and increased small airways obstruction (FEV1/FVC, ß = -0.37, p = .05; FEV25-75%, ß = -0.351, p = .016). Higher BLL appears to be an independent modulator of hypertension and poor pulmonary function upon occupational lead exposure in lead-acid battery recyclers.

Silicosis, progressive massive fibrosis and silico-tuberculosis among workers with occupational exposure to silica dusts in sandstone mines of Rajasthan state: An urgent need for initiating national silicosis control programme in India.

CONTEXT: Silicosis is a progressive, irreversible and incurable respiratory morbidity and often becomes a cause for pre-mature mortality among occupationally silica dust-exposed workers in India and similar countries. It has a dual problem of associated silico-tuberculosis as a co-morbidity. The present study was done to assess the respiratory morbidity caused by silicosis in sandstone mine of Rajasthan, India. METHODS: The chest X-rays of 529 subjects having history of employment in stone mines with respiratory morbidity were subjected for this study and evaluated in accordance with ILO Classification 2000. The X-rays were classified into various categories of silicosis and progressive massive fibrosis (PMF) in relation to years of work in stone mines. RESULTS: Out of 529 chest radiographs evaluated, 275 (52%) showed radiological evidence of silicosis. Of them, 40 (7.5%) subjects showed large opacities suggestive of progressive massive fibrosis. Both silicosis and progressive massive fibrosis were associated with increasing duration of work in stone mines. Sixty-one (12.4%) subjects with silicosis also had associated pulmonary tuberculosis, termed as silico-tuberculosis. CONCLUSION: The present study showed a high prevalence of silicosis, progressive massive fibrosis and silico-tuberculosis among stone mine workers. It appears that that unless silicosis is controlled, elimination of tuberculosis is far from reality in the country. Hence, states and central authorities must work together towards control of both silicosis as well as silico-tuberculosis. Similarly, there is an urgent need of initiation of national silicosis control programme, similar to existing national tuberculosis control programme, considering the huge burden of silicosis in India.

Club cell protein 16 as a biomarker for early detection of silicosis.

Background & objectives: Clinically silicosis is diagnosed by chest X-ray showing specific opacities along with history of silica dust exposure. Diagnosis is invariably made at an advanced or end stage when it is irreversible. Moreover, silicosis patients are susceptible to develop tuberculosis. Therefore, a suitable biomarker for early detection of silicosis is needed. This study evaluated the suitability of club cell protein (CC16) as a biomarker for early detection of silicosis. Methods: This pilot study included 121 individuals from X-ray-confirmed/advanced silicosis, moderate silica dust-exposed workers and healthy controls from western India. CC16 levels were quantified in serum samples through ELISA. Sensitivity and specificity of CC16 values at different cut-off points were calculated in both non-smokers and smokers. Results: Serum CC16 level was significantly (P <0.01) decreased in X-ray confirmed advanced silicosis patients (4.7±3.07 ng/ml) followed by moderately exposed workers (10.2±1.77 ng/ml) as compared to healthy non-exposed individuals (16.7±3.81 ng/ml). Tobacco smoking also caused a significant decrease of serum CC16 concentration in both healthy (10.2±1.12 ng/ml) and advanced silicosis workers (2.6±2.28 ng/ml) compared to non-smokers. Sensitivity and specificity of CC16 values were also found to be ≥83 per cent for screening all categories of individuals. Interpretation & conclusions: Because of high sensitivity and specificity, serum CC16 could be used as predictive biomarker for suspicion and early detection of silicosis, which would help in reducing/delaying premature deaths caused by silicosis. It would also control silicotuberculosis additionally.

Transmission dynamics of hepatitis C virus among intra venous drug users in the border state of Manipur, India.

Intra venous drug users (IVDUs) are at high risk for hepatitis C virus (HCV) infection owing to their high rate of drug abuses. The north-eastern part of India has a high prevalence of IVDUs with Manipur being the worst hit state. The aim of the study was to document the molecular epidemiology, the patterns of HCV transmission, genomic variation and recombination events within HCV genome among IVDUs of Manipur, India. 91 anti-HCV sero-reactive blood samples were collected from IVDUs in Manipur. The samples were processed for RNA extraction, nested RT-PCR, sequencing and quantitative viral RNA estimation. Phylogeographic analysis of the sequenced core and NS5B regions of HCV genome was performed to determine the probable transmission route and recombinant HCV strains. 83 out of 91 anti-HCV seropositive samples were RNA positive (91.20%) based on 5'UTR of HCV genome by nested RT-PCR. Of the RNA positive samples, 73 paired partial core and NS5B gene were sequenced. Three major genotype and eight subtypes were detected while no recombinant strains were found. Individuals with genotype 1 had the mean viral load (5.94 ± 0.705 log10IU/ml) followed by genotype 3 (4.91 ± 0.49 log10IU/ml) and 6 (3.96 ± 0.32 log10IU/ml). The viral load was statistically significant among the male individuals at 4.822 ± 1.36 log10IU/ml compared to 4.767 ± 0.49 log10IU/ml for females (t=3.249, p<0.005). The phylogeographic results indicated 3b, 6h originated from Vietnam, 1a had Indian origin, 3a, 6k originated from southern China while 1b originated from Myanmar, respectively. The incidence of eight different subtypes in Manipur reflects the transmission of these strains from the "Golden Triangle" drug trafficking regions. Sequence analysis confirmed the transmission routes of HCV, which is linked to China and Vietnam for the newly emergent genotype 6 in north-eastern India.

Oncogenic HPV among HIV infected female population in West Bengal, India.

BACKGROUND: Prevalence of both cervical cancer and Human Immunodeficiency Virus (HIV) infection are very high in India. Natural history of Human Papilloma Virus (HPV) infection is known to be altered in HIV positive women and there is an increased possibility of persistence of HPV infections in this population. Therefore, this study was conducted to understand the epidemiology and circulating genotypes of oncogenic HPV among HIV positive and negative female population in West Bengal, India. METHODS: In this hospital-based cross-sectional study, 93 known HIV positive females attending a pre-ART registration clinic and 1106 HIV negative females attending a Reproductive and Child Health Care Clinic were subjected to study. Cervical cell samples collected from the study population were tested for the presence of HPV 16, 18 using specific primers. Roche PCR assay was used to detect other specific HPV genotypes in the cervical cells specimens of HIV positive cases only. RESULTS: Prevalence of HPV 16, 18 among HIV positive females (32.2%; n = 30) was higher than HIV negative females (9.1%; n = 101). About 53% (23/43) of cases with oncogenic HPV were infected with genotypes other than 16, 18 either as single/multiple infections. HPV 18 and HPV 16 were the predominant genotypes among HIV positive and HIV negative subjects respectively. Oncogenic HPV was not found to be associated with age and duration of sexual exposure. But the presence of HIV was found to a statistically significant predictor oncogenic HPV. CONCLUSION: The currently available HPV vaccines offer protection only against HPV 16 and 18 and some cross- protection to few associated genotypes. These vaccines are therefore less likely to offer protection against cervical cancer in HIV positive women a high percentage of who were infected with non-16 and non-18 oncogenic HPV genotypes. Additionally, there is a lack of sufficient evidence of immunogenicity in HIV infected individuals. Therefore, prevention of cervical cancer in HIV positive women must be focused towards early detection of oncogenic HPV & cervical cytological abnormality followed by an appropriate treatment.

Oncogenic human papilloma virus and cervical pre-cancerous lesions in brothel-based sex workers in India.

A community-based cross-sectional study was conducted in brothel-based sex workers of West Bengal, Eastern India, to determine their oncogenic human papillomavirus (HPV) status and the presence of pre-cancerous lesions. A total of 229 sex workers from three districts of West Bengal participated in the study. All the study participants were interviewed with the aid of a pre-tested questionnaire to determine their sociodemographics, risk behaviour and risk perceptions after obtaining informed verbal consent. The interview was followed by collection of cervical cells from all participants using a disposable vaginal speculum and cervical cytobrush. Oncogenic HPV DNA was detected by real-time polymerase chain reaction (PCR). A simultaneous Papanicolaou test ('Pap smear') was performed to detect cervical cytological abnormalities. Overall, the prevalence of oncogenic HPV was found to be 25% (58/229) among the studied population. A subset (n=112) of the sample was tested separately to determine the existence and magnitude of HPV genotypes 16 and 18. The results showed that genotype 16 was prevalent in 10% (11/112), genotype 18 in 7% (8/112) and both genotype 16 and 18 in 7% (8/112). The HPV prevalence rate showed a decreasing trend with age, being 71.4% in the 10-19 years age group, 32.3% in the 20-29 years age group, 18.3% in the 30-39 years age group and 2.5% in the >or=40 years age group (statistically significant differences, P1 year, respectively. This difference was found to be statistically significant both by univariate and multivariate analysis. In this study, it was observed that sex workers with an average number of daily clients of six or more had an HPV prevalence of 67% (n=6), those with four to five clients had a prevalence of 45% (n=9), those with two to three clients had a prevalence of 30% (n=34) and those with one or less clients had a prevalence of 10% (n=9) (statistically significant differences, P=0.00003). Multivariate analysis showed a statistical association only with a duration of sex work of or=101 (OR=2.5; 95% CI 1.3-5). Regarding pre-cancerous lesions, 2 of 229 sex workers showed the presence of a low-grade squamous intraepithelial lesion along with high-risk HPV. Thus, 1% of the studied population suffer from a pre-cancerous lesion caused by high-risk HPV. This study concludes that young sex workers are particularly vulnerable to high-risk HPV, similar to human immunodeficiency virus (HIV). The observation of older sex workers relatively free from HPV supports the view of acquired immunity against HPV, which needs to be studied in-depth further. There is a need for a suitable community-based intervention programme targeted towards sex workers, with special reference to younger sex workers, for control and prevention of HPV and cervical cancer. Vaccination against HPV for newly entrant sex workers may be an important component for a successful intervention programme.

Phylogenetic analysis of the p24-p7 region of the human immunodeficiency virus type 1 gag gene to determine subtype distribution among female sex workers in Calcutta, India.

Human immunodeficiency virus type 1 (HIV-1) subtype C, based on the envelope region, has been reported to be predominant in India. We sequenced the p24-p7 gag region from 51 HIV-1 seropositive female sex workers in Calcutta, India, for more-detailed molecular characterization. Subtype C was found to be prevalent, although no strong monophyletic cluster was observed.

Evaluation of sexually transmitted diseases/human immunodeficiency virus intervention programs for sex workers in Calcutta, India.

BACKGROUND AND OBJECTIVE: The Sonagachi Project in Calcutta, India, organized sex workers to improve working conditions. GOAL: To compare rates of sexually transmitted diseases between the Sonagachi Project and other areas in which only the National AIDS Control Organization (NACO) interventions were implemented. STUDY: A cross-sectional survey of randomly selected female sex workers. RESULTS: There was no difference in the prevalence of all STDs between the 2 areas; both were lower than reported in other surveys in 1992. Analysis using propensity scores also failed to demonstrate any difference. The number of preventive activities was similar in the Sonagachi and NACO-only areas but was more prevalent than in 1992. Sex workers in the Sonagachi area had better treatment-seeking behavior and attitudes. Both the Sonagachi and NACO strategies have resulted in lower STD rates, but the Sonagachi Project also increased the proportion who had an optimistic attitude and increased prevention and treatment-seeking behavior.

Determination of gag subtypes of HIV type 1 detected among female sex workers in Calcutta, India.

HIV-1 subtyping is important to study the changing scenario of genetic variation. The gag-based heteroduplex mobility assay (gag-HMA) was developed and evaluated as a powerful and reliable technique for identifying the HIV-1 group M subtypes A to H and the circulating recombinant forms (CRFs). To study the subtype distribution of HIV-1 strains from the eastern part of India, we used the gag-based HMA, followed by the sequencing and phylogenetic analysis. Blood samples from HIV-1-seropositive female sex workers in Calcutta were subjected to gag-HMA. The most prevalent subtype was found to be the C type, among which the C4 subsubtype was prevalent. However, a number of nontypable C strains were found in gag-HMA. Phylogenetic analysis revealed the discrete nature of the C strains and no monophyletic cluster was noticed. This result might indicate a growing tendency of variations among the HIV-1 type C strains circulating in eastern India.

Determination of gag and env subtypes of HIV-1 detected among injecting drug users (IDUs) in Manipur, India: evidence for intersubtype recombination.

The majority of HIV-1 transmission in Manipur, one of the northeastern states of India, is through the sharing of needles and syringes among the injecting drug users (IDUs). A total of 28 HIV seropositive samples were used to determine the HIV-1 subtypes with respect to both gag and envelope genes. The specific regions within gag and envelope genes were amplified from PBMC DNA by nested PCR using appropriate primers. These amplicons were used in heteroduplex mobility assay followed by DNA sequencing. Phylogenetic analysis of the nucleotide sequences of respective regions showed that 89% of samples (25/28) were infected with subtype C with respect to both gag and envelope genes; however, 11% of the samples (3/28) showed subtype discordance with respect to the envelope (C2-V3) and gag (p24-p7) genomic regions. Simplot analysis of the discordant samples showed the presence of intersubtype recombination between subtype C and Thai B; two samples were found to be subtype C in envelope but Thai B in gag, whereas, one sample was found to be subtype Thai B in envelope and 'C' in gag region.