Indoor Urban Environment and Conventional Risk Factors for Pediatric Tuberculosis Among 1-12 Years Old Children in a Megacity in Pakistan: A Matched Case-Control Study.

Background: Estimated 1.1 million children developed tuberculosis (TB) globally in 2020. Household air pollution has been associated with increased respiratory tract infections among children. Nonetheless, there are scarce data regarding the association of indoor environment with pediatric TB. Objectives: To determine the association of indoor urban environment and conventional risk factors for pulmonary TB among children 1-12 years and to discern the differences of these factors among younger (1-5 years) and older children (6-12 years). Materials and Methods: We conducted an age-matched case-control study among children in 2 hospitals (tertiary and secondary care) in megacity, Karachi, Pakistan. A total of 143 pulmonary TB cases, diagnosed on Pakistan Paediatric Association Scoring Chart for Diagnosis of Tuberculosis (PPASCT), were compared with 286 age-matched controls (ratio 1:2). Indoor urban environment and other conventional risk factors were ascertained through a questionnaire and analyzed by conditional logistic regression. Results: Overall, being a female child [matched odds ratio (mOR): 2.03, 95% confidence interval (CI): 1.16-3.53], having household TB contact (mOR: 8.64, 95% CI: 4.82-15.49), open kitchen for cooking in household (mOR: 1.99, 95% CI: 1.59-5.66), and poorly ventilated house (mOR: 2.37, 95% CI: 1.09-3.65) increased the risk of TB among children (1-12 years). Open kitchen was a risk factor for younger children (1-5 years), whereas poorly ventilated house and being female child was a risk factor for older children (6-12 years), respectively. Conclusions: This study strengthens the evidence that a poor indoor environment increases the risk for childhood TB. Concerted efforts are needed to improve the indoor air environment in urban areas for prevention of TB in addition to addressing the conventional risk factors.

Lead In Food And Its Correlation With Blood Lead Levels Among Pregnant Women Of Sindh, Pakistan.

BACKGROUND: With increasing control of lead (Pb) in gasoline, food has emerged as an important secondary pathway for Pb exposure globally. This study assessed Pb levels in food duplicates and blood. Furthermore, it assessed the correlation of Pb in food duplicates and blood Pb levels with common food items taken by pregnant women of Sindh, Pakistan. METHODS: A cross-sectional study was conducted from August 2014 to November 2015, in urban (Karachi) and rural (Gambat, Khairpur) area of Sindh-Pakistan. A total of 103 venous blood samples (Karachi = 63 and Gambat = 40) of pregnant women were measured for blood Pb levels at the time of delivery. One month post-delivery, food frequency questionnaire (FFQ) was administered and three-day food duplicates (same number of cooked portions of food eaten by women) were collected. Food duplicates were analysed for Pb levels. Multivariable linear regression was conducted to identify the frequency of food items which contribute to blood and food Pb levels of pregnant women, separately. RESULTS: With 90% confidence interval, chapati (local flat bread) (ß=0.20, p<0.001), boiled rice (ß=0.35, p<0.001), cooked root vegetables (ß= 0.16, p=0.03), fried savory items (ß=0.15, p=0.03), sweet snacks (ß=0.13, p=0.08) were positively associated with elevated mother blood Pb levels. While cream biscuits (ß =-0.14, p=0.04), lassi (blend of yogurt, water and spices) (ß= -0.31, p<0.01), market milk desserts (ß=-0.22, p<0.001), fish (ß= -0.16, p=0.02), soft drinks (ß= -0.19, p=0.01) and supari/gutka (betel-nut) (ß=-0.13, p= 0.06) were negatively associated with mother Pb levels. Tetra-pak market juices (ß= 0.30, p<0.001) and cooked root vegetables (ß=0.19, p=0.05) were positively associated with mother food Pb levels, at 90% CI. CONCLUSIONS: Bread, boiled rice, fried savoury items, sweet snacks and cooked root vegetables were contributing to blood Pb levels of pregnant women in Pakistan. These food items may be contaminated with Pb during processing, packaging and storage. Inverse relation of Supari/gutka and soft drinks with blood Pb levels may be due its overall reduction in absorption capacity of the gut for nutrients. Objective individual food item analysis for Pb is warranted for further intervention.

Contribution of house dust contamination towards lead exposure among children in Karachi, Pakistan.

Lead exposure is associated with impaired neurodevelopment among children. House dust is recognized as one of the important secondary sources of lead exposure in children. We assessed the relationship between lead contamination in house dust and blood lead level in Pakistani children. We investigated lead contamination in house dust samples collected from 59 houses in Karachi, Pakistan. The lead content of house dust in Pakistan was relatively higher than that reported in previous studies. Weekly lead intakes from house dust were considerably higher among Pakistani children. In Pakistani children, 12% (7 of 58) showed lead intake values greater than the previous Provisional Tolerable Weekly Intake of lead. A correlation (Pearson's correlation = 0.37) was found between weekly lead intake from house dust and blood lead level in Pakistani children. In addition, blood lead levels were significantly higher in children with high lead intakes than in children with low and medium lead intakes. Thus, house dust is an important source of lead exposure in Pakistani children.

Acute coronary syndrome and use of biomass fuel among women in rural Pakistan: a case-control study.

OBJECTIVES: Three billion people use biomass fuel for cooking and heating globally. We assessed the association between acute coronary syndromes (ACS) and use of biomass fuel for cooking. METHODS: We conducted a case-control study among women living in defined areas that were served by two tertiary care hospitals. A total of 364 women admitted to cardiac care units with ACS were compared with 727 controls, individually matched for age, who were inpatients at the same hospitals with a miscellany of diagnoses. Exposure to biomass fuel and other risk factors was ascertained through a questionnaire and assessed by conditional logistic regression. RESULTS: After adjustment, risk of ACS was elevated in women who had ever used biomass for cooking. In comparison with never users, the odds ratio for those who currently cooked with biomass was 4.8 (95% confidence interval 1.7, 13.8). However, among those who had ever used biomass, there was no decline in risk with time since last exposure. CONCLUSIONS: The study found increased risk of ACS from use of biomass for cooking. However, full benefits from interventions may not accrue in short term.

Covering the last mile for vaccination: Feasibility and acceptability of traditional birth attendant-based referral system in hard-to-reach areas in rural Pakistan.

BACKGROUND: Pakistan has a decent network of community-based workers including lady health workers (LHWs) and vaccinators. However, a major section of the population is not covered by LHWs/vaccinators, labeled here as hard-to-reach (HTR) areas, where immunization coverage is also considerably low. This study explored the feasibility of engagement of traditional birth attendants (TBAs) to improve EPI vaccination coverage in HTR areas in rural Sindh, Pakistan. METHODS: This implementation research was conducted in two sub-districts of Sukkur (a district in Sindh Province). In an HTR selected intervention arm, TBAs were trained for vaccination and monetary incentives were provided to counsel and refer mothers for vaccination. While LHWs covered areas in the adjacent sub-district were provided with refresher training for vaccination only without any monetary incentive, and were considered as control arm. Considering the inherent differences in intervention and comparison group (HTR intervention area being worse regarding infrastructure and access), between groups and within group change in knowledge of TBA/LHWs and vaccination coverage was assessed before and after the intervention. Furthermore, focus group discussions were conducted with vaccinators, TBAs and LHWs and in-depth interviews with supervisors of vaccinators. RESULTS: TBAs and LHWs' vaccine related knowledge increased significantly after training (pretest vs post test score: 10.5 to 15.4). The BCG coverage improved 74.1% (percentage change) in TBA arm. While completion of vaccination (ie, Penta-3 coverage) increased by 147% from baseline following the intervention. The TBAs, LHWs, vaccinators and their supervisors all welcomed the initiative and considered it as a feasible option. CONCLUSIONS: Involvement of TBAs' to form a referral system has potential to improve vaccine coverage and completion in HTR areas in Pakistan. The system is acceptable to the population and implementation is feasible due to availability of TBAs. However, in order to sustain the initiative minimal incentive need to be provided to TBAs to improve the vaccination coverage. Compared to establishing the infrastructure in HTR the intervention seems less costly however, it requires formal cost-effective or cost-benefit analysis.

Inequities in Antenatal Care, and Individual and Environmental Determinants of Utilization at National and Sub-national Level in Pakistan: A Multilevel Analysis.

BACKGROUND: Nationally representative surveys are vital for gauging progress in health and planning health services. However, often marred with inadequate analysis to provide any guidance to health policy and planning. Most recent Pakistan Demographic and Health Survey (PDHS) 2012-2013 is an inclusive nationally representative investigation. Nonetheless, its published report offers limited evidence regarding antenatal care (ANC). Furthermore, after 18th constitutional amendment, policies are principally made at provincial level in Pakistan; therefore, it is imperative to have contextual evidence at sub-national level to feed programs and policies. METHODS: We analysed 7142 women with a recent birth, to assess the individual and environmental determinants of ANC, adapting Andersen's model of healthcare utilization, by multilevel analysis. Separate models of determinants were developed for the national level and five provinces using survey command in Stata version 12.1. RESULTS: Besides that the recommended ANC coverage (≥4 visits) is low in Pakistan (36%), gross inequities exist predominantly across provinces (12% to 82%). Small differences exist between urban and rural localities. Education, health literacy and socio-economic status of women were strong predictors, while communities with high concentration of literate women very strongly predict ANC use (odds ratio [OR] = 12). Determinants of ANC vary at national and at sub-national level. For example, women's education had no influence on ANC utilization in Khyber Pakhtunkhwa (KPK) and Baluchistan (BC) provinces. Notably, husband's education was significantly associated with ANC utilization in KPK only. Significant positive interaction exists between urban areas and larger provinces (Punjab, Sindh, and KPK). Also, very strong positive interaction occurs when women have secondary or particularly higher level of education and living in urban areas or larger provinces. CONCLUSION: This study highlights conspicuous contextual differences which determine maternal care at national and sub-national level. It identified contextual factors which are important for planning maternal health services between and within provinces. High positive interaction for ANC utilization between women education, urban areas and larger provinces highlights the inequities which need to be addressed. It also identified factors at the community level (cluster) which relates to overall context and influence individual behavior and highlights the diminishing urban-rural gap in service utilization in Pakistan.

Pulmonary Tuberculosis Is Associated With Biomass Fuel Use Among Rural Women in Pakistan: An Age- and Residence-Matched Case-Control Study.

Facility-based, age- and residential area-matched case-control study was conducted in Sindh, Pakistan to determine association between biomass fuel use for cooking and pulmonary tuberculosis (TB). Cases were women with pulmonary TB, and controls were those suffering from other diseases. Current users of biomass fuel were at higher risk of pulmonary TB (adjusted matched odds ratio [mOR] = 3.0; 95% CI = 1.1-4.9) compared with nonusers. In comparison with former biomass users (women not using biomass for >10 years), recent biomass users (women who switched from biomass to nonbiomass ≤10 years ago), and current (lifetime) users were at a higher risk in a dose-response manner (adjusted mOR = 2.8, 95% CI = 0.9-8.2 and adjusted mOR = 3.9, 95% CI = 1.4-10.7, respectively). Population attributable fraction for TB related to biomass fuel use was 40.6% (95% CI = 35.5%-45.7%). This study strengthens the evidence that biomass fuel use for cooking is associated with pulmonary TB and risk increases with duration of exposure.

Lead Exposure Assessment among Pregnant Women, Newborns, and Children: Case Study from Karachi, Pakistan.

Lead (Pb) in petrol has been banned in developed countries. Despite the control of Pb in petrol since 2001, high levels were reported in the blood of pregnant women and children in Pakistan. However, the identification of sources of Pb has been elusive due to its pervasiveness. In this study, we assessed the lead intake of pregnant women and one- to three-year-old children from food, water, house dust, respirable dust, and soil. In addition, we completed the fingerprinting of the Pb isotopic ratios (LIR) of petrol and secondary sources (food, house-dust, respirable dust, soil, surma (eye cosmetics)) of exposure within the blood of pregnant women, newborns, and children. Eight families, with high (~50 µg/dL), medium (~20 µg/dL), and low blood levels (~10 µg/dL), were selected from 60 families. The main sources of exposure to lead for children were food and house-dust, and those for pregnant women were soil, respirable dust, and food. LIR was determined by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) with a two sigma uncertainty of ±0.03%. The LIR of mothers and newborns was similar. In contrast, surma, and to a larger extent petrol, exhibited a negligible contribution to both the child's and mother's blood Pb. Household wet-mopping could be effective in reducing Pb exposure. This intake assessment could be replicated for other developing countries to identify sources of lead and the burden of lead exposure in the population.

External lead contamination of women's nails by surma in Pakistan: Is the biomarker reliable?

Adverse health effects of heavy metals are a public health concern, especially lead may cause negative health impacts to human fetal and infantile development. The lead concentrations in Pakistani pregnant women's nails, used as a biomarker, were measured to estimate the lead exposure. Thirteen nail samples out of 84 nails analyzed contained lead higher than the concentration (13.6 µg/g) of the fatal lead poisoning case, raising the possibility of an external contamination. Eye cosmetics such as surma are recognized as one of the important sources of lead exposure in Pakistan. We collected in Pakistan 30 eye cosmetics made in Pakistan, Saudi Arabia and western countries. As the metal composition analysis by energy dispersive X-ray fluorescence spectrometry revealed that some surma samples contained lead more than 96%, the surma might contaminate the nail specimen. Scanning electron microscopy observations showed that lead-containing surma consists of fine particle of galena (ore of lead sulfide) in respirable dust range (less than 10 µm). In addition, relative in vitro bioavailability of lead in the surma was determined as 5.2%. Thus, lead-containing surma consists of inhalable and bioavailable particles, and it contributes an increased risk of lead exposure. Moreover, the relationship between the surma and the lead-contaminated nails by lead isotope ratios analysis indicated the potential of lead contamination in nails by surma. These results suggest that lead in the nails was derived both from body burden of lead and external contamination by lead-containing surma. Therefore, nail is not suited as a biomarker for lead exposure in the countries where surma used, because we may overestimate lead exposure by surface lead contamination in the nail by surma.

Exposure assessment of lead from food and airborne dusts and biomonitoring in pregnant mothers, their fetus and siblings in Karachi, Pakistan and Shimotsuke, Japan.

AIM: Exposure assessment of lead (Pb) and Arsenic (As) from food, water, and house dust intake were assessed among pregnant women, their children and fetuses in Pakistan and Japan, as well as their body burden of the metals in their blood. METHOD: Fifty families which included a pregnant woman, a fetus and the 1-3-year-old siblings were recruited in Karachi and Khairpur in Pakistan, and Shimotsuke and Asahikawa in Japan, respectively. Their dietary exposure to Pb and As was measured in 3-day food duplicates and drinking water by ICP-MP. Pb in house dust and respirable dust was evaluated with an energy dispersive X-ray fluorescence spectrometry. Non-radioactive isotope Pb profiles of blood specimens will be compared with those of the exposure origins, such as food duplicates, respirable house dust, the soils nearby, and gasoline. RESULTS: Judging from the data collected and analyzed so far, contribution from dietary intake is highly correlated to higher body burden of Pb among Pakistani mothers. Additional data analyses will reveal the status of Pb and As body burden in Pakistani mothers, fetuses and their siblings, and causal sources of high body burden is delineated by Pb isotope profile analysis of different sources of Pb exposure.

Burden of asthma among children in a developing megacity: childhood asthma study, Pakistan.

OBJECTIVES: Global burden of childhood asthma has increased in the past few decades, particularly in low-income countries. In Pakistan, there is a lack of community-based epidemiological studies estimating the burden of asthma among children. This study determined the prevalence and predictors of asthma among children 3-17 years of age in Karachi, Pakistan. METHODS: A two-stage community-based representative cross-sectional survey was conducted in Karachi from March 2012 to April 2013 comprising 1046 children aged 3-17 years. Of 7500 clusters, 80 were randomly selected, and of these, 15 children per cluster were enrolled randomly. A translated and pre-tested version of International Study of Asthma and Allergies in Children questionnaire was administered. RESULTS: The overall prevalence of asthma among study participants was 10.2% (95% CI: 8.4-12.0). Asthma was more likely to occur among boys (adj. OR: 2.5, 95% CI: 1.6-4.0), children in the younger age group (3-7 years) (adj. OR: 2.9, 95% CI: 1.7-4.8), those living in households with ill-ventilated kitchens (adj. OR: 1.8, 95% CI: 1.1-3.1), having family history of asthma (adj. OR: 2.3, 95% CI: 1.3-3.9) and those of the Sindhi ethnicity (adj. OR: 2.2, 95% CI: 1.1-4.4). CONCLUSION: This study is the first robust evidence regarding asthma among children in Pakistan, reporting a high burden in this group. Family history, male gender, Sindhi ethnicity and ill-ventilated kitchen were identified as important predictors of asthma. Targeted preventive measures and intervention studies are required to better understand and reduce the burden of asthma among children in Pakistan.