Ocular morbidity among children (aged 6-18 yr) of the tribal area of Melghat, India: A community-based study.

BACKGROUND OBJECTIVES: Most of the ocular morbidities among school children are preventable or treatable. Melghat, a difficult to access, hilly, forest, tribal area with poorly developed infrastructure in the Amravati district of Maharashtra. Scarcity of ophthalmologists and low health-seeking behaviour of tribal people contributes to the high burden of ocular morbidity. Given the lack of published studies on the ocular morbidity among children in Melghat, outreach programmes are essential to diagnose and treat visual impairments promptly. The objective was to determine the prevalence of ocular morbidity among children in the tribal area of Melghat. METHODS: A community-based observational study was carried out in the Chikhaldara and Dharni blocks of Melghat. Children from 15 tribal villages were screened for eye disorders by trained paramedics. Most of the children were examined by an ophthalmologist. We used Chi-square test for categorical variables. RESULTS: A total of 4357 children aged between 6 and 18 yr were examined. Of these 2336 (53.6%) were females and 2021 (46.4%) were males. Out of 4357 children, 507 (11.63%) had an ocular morbidity. The prevalence of ocular morbidity and refractive error increased in the age group of 8-10 yr (P<0.05 and <0.001, respectively). Refractive error was the most common ocular morbidity (n=339; 7.8%), followed by vitamin A deficiency (VAD) (n=120; 2.8%). INTERPRETATION CONCLUSIONS: The prevalence of refractive error and VAD in this study was significantly higher than the rest of India and the world. For the prevention of childhood blindness, immediate intervention programme, including eye screening by trained paramedics, treatment by an ophthalmologist and prophylaxis, is crucial.

Impact of socioeconomic status and living condition on latent tuberculosis diagnosis among the tribal population of Melghat: A cohort study.

AIMS: To study socioeconomic status (SES) and living conditions (LC) as risk factors for latent tuberculosis infection (LTBI) and their impact on QuantiFERON-TB gold (QFT-G) and tuberculin skin test (TST) outcome for determining a better diagnostic test for LTBI in the malnourished tribal population of Melghat. SETTINGS AND DESIGN: Six hundred sixty nine participants matching the inclusion criteria were recruited from 10 tribal villages of Melghat region, India. SUBJECTS AND METHODS: Complete information related to various risk factors and test outcome was obtained on 398 participants, which was analyzed as per predefined conceptual framework. Factors were classified based on their relevance either at individual or household level, and subsequently based on the possibility of intervention. Data were partitioned into concordant and discordant sets depending on test agreement. RESULTS: In concordant set, the two tests revealed that LTBI was significantly associated with smoking (adjusted odds ratio [aOR]: 2.64 [95% confidence interval [CI]: 1.03-6.79]), tobacco usage (aOR: 2.74 [95% CI: 1.50-4.99]), and malnourishment (aOR: 1.97 [95% CI: 1.12-3.48]) after basic adjustment. Inclusion of latent variable SES and LC in the model has mediating effect on the association of above factors with LTBI. Further, the association of SES and LC with LTBI in concordant set was unaltered in presence of other cofactors. From discordant set, results of QFT-G corroborated with that of concordant set. CONCLUSIONS: Poor SES and LC can be considered as strong risk factors linked with LTBI as compared to malnourishment, which is often targeted in such communities. Further, our study showed QFT-G test as a reliable tool in screening of LTBI in the tribal population of Melghat, India.

Differential Levels of Alpha-2-Macroglobulin, Haptoglobin and Sero-Transferrin as Adjunct Markers for TB Diagnosis and Disease Progression in the Malnourished Tribal Population of Melghat, India.

Lack of diagnostic capacity has been a crucial barrier preventing an effective response to the challenges of malnutrition and tuberculosis (TB). Point-of-care diagnostic tests for TB in immuno-incompetent, malnourished population are thus needed to ensure rapid and accurate detection. The aim of the study was to identify potential biomarkers specific for TB infection and progression to overt disease in the malnourished population of Melghat. A prospective cohort study was conducted in the year 2009 through 2011 in six villages of the Melghat region. 275 participants consisting of malnourished cases with a) active TB (n = 32), b) latent TB infection (n = 90), c) with no clinical or bacteriological signs of active or latent TB (n = 130) and healthy control subjects (n = 23) were recruited for the study. The proteome changes of the host serum in response to Mycobacterium tuberculosis (M.tb) infection were investigated using one dimensional electrophoresis in combination with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Three most differentially expressed proteins; alpha-2-macroglobulin (A-2-M), sero-transferrin and haptoglobin were identified by MALDI-TOF MS analysis, which were up-regulated in the malnourished patients with active TB and down-regulated in the malnourished patients compared with the healthy controls. Additionally, follow-up studies indicated that the expression of these proteins increased to nearly two folds in patients who developed active disease from latent state. Our preliminary results suggest that A-2-M, sero-transferrin and haptoglobin may be clinically relevant host biomarkers for TB diagnosis and disease progression in the malnourished population. This study provides preliminary framework for an in-depth analysis of the biomarkers in larger well-characterized cohorts. Evaluation of these biomarkers in follow-up cases may further aid in improving TB diagnosis.

The assessment of cytokines in Quantiferon supernatants for the diagnosis of latent TB infection in a tribal population of Melghat, India.

The tuberculin skin test (TST) and interferon-gamma release assays (IGRA), namely, the QuantiFERON-TB Gold test (QFT), remain the standard immunological diagnostic tools for latent tuberculosis (TB) infection (LTBI). However, the sub-optimal detection rates of both of these tests are major impediments in recognizing the population at risk. This study was aimed at evaluating additional cytokines besides interferon-gamma (IFN-γ) as biomarkers for improving LTBI diagnosis in the tribal population of Melghat, India. Seventy-four close TB contacts were stratified by QFT and TST results into: (i) QFT+/TST+ (n = 26), (ii) QFT+/TST- (n = 12), (iii) QFT-/TST- (n = 35) and (iv) QFT-/TST+ (n = 1) groups. A panel of cytokines (IL-6, IL-10, TNF-α and IL-2R) was then evaluated in antigen-stimulated QFT cell-free culture supernatants using IMMULITE-1000, an automated immunoassay analyzer. Cytokine estimation showed significantly higher levels of IL-6 in the QFT+/TST+ group, while significantly higher levels of IL-10 were found in the QFT-/TST- group. Correlation analysis identified a positive correlation between IL-6 and the QFT response (r = 0.6723, P < 0.0001), while a negative correlation was seen between QFT and IL-10 expression (r = -0.3271, P = 0.0044). Similarly, IL-6 was positively correlated with TST levels (r = 0.6631, P <0 .0001), and conversely, a negative correlation was found between TST and IL-10 expression (r = -0.5698, P < 0.0001). The positive and negative predictive values of IL-6 were found to be 92.59 and 93.33%, respectively, and the positive and negative predictive values of IL-10 were 96.55 and 91.18%, respectively. No significant impact of the demographic characteristics on cytokine positivity was observed. Our preliminary results suggest that the evaluation of additional cytokines in QFT cell-free culture supernatants may be valuable for the identification of LTBI. Combining IL-6 and IL-10 with QFT and/or TST could markedly improve the detection accuracy of LTBI. Our observations require investigation in larger well-characterized cohorts along with follow-up studies to further confirm the study outcome.

Laboratory investigations on the diagnosis of tuberculosis in the malnourished tribal population of melghat, India.

BACKGROUND: Malnutrition is a major risk factor for the development of tuberculosis (TB). In India, Melghat is among the tribal regions which consist of highest number of malnutrition cases. Because of the paucity of TB data from these malnourished areas there is an urgent need for the development and evaluation of improved TB diagnostic tests. In the present study, three in house developed diagnostic tests namely TB-Ag(antigen) ELISA, Adenosine deaminase (ADA) estimation and IS6110 polymerase chain reaction (PCR) assay were investigated for the detection of Mycobacterium tuberculosis (M. tb.) infection. METHODS: For investigation, blood samples were collected from 128 study subjects from six villages of Melghat tribal area and evaluated using three in house developed assays, namely TB-Ag ELISA, ADA estimation and IS6110 PCR. RESULTS: The TB-Ag ELISA method yielded 83% sensitivity and 94% specificity. The ADA and PCR assay gave a sensitivity of 61% and 49% and specificity of 62% and 98% respectively. A considerable good agreement of 82.81% (k=0.472) between TB-Ag ELISA and PCR was observed. The overall sensitivity of TB-Ag ELISA was significantly higher (p<0.05) than the ADA and PCR while PCR yielded highest specificity among all the three evaluated tests. CONCLUSIONS: We concluded that the routine use of TB-Ag ELISA can be useful for screening of suspected TB patients in the malnourished population where sophisticated laboratory set up is difficult.