Weather factors, PCV intervention and childhood pneumonia in rural Bangladesh.

Available evidence is limited on the association between weather factors and childhood pneumonia, especially in developing countries. This study examined the effects of weather variability on childhood pneumonia after the introduction of pneumococcal conjugate vaccines (PCV) intervention in rural Bangladesh. Data on pneumonia cases and weather variables (temperature and relative humidity) between the 1st January 2012 and the 31st December 2016 were collected from Matlab Hospital, International Centre for Diarrhoeal Disease Research, Bangladesh, and Bangladesh Meteorological Department, respectively. Time series cross-correlation functions were applied to identify the time lags of the effect of each weather factor on pneumonia. Generalized linear regression model with Poisson link was used to quantify the association between weather factors and childhood pneumonia after adjustment of PCV intervention. The annual incidence rate of pneumonia reduced from 5691/100,000 to 2000/100,000 after PCV intervention. Generalized linear regression model suggested that temperature had a negative association with childhood pneumonia (relative risk, 0.985; 95% confidence interval (CI), 0.974-0.997), and PCV intervention was a protective factor with the relative risk estimate of 0.489 (95% CI, 0.435-0.551). However, no substantial association was found with relative humidity. PCV intervention appeared protective against childhood pneumonia, and temperature might be associated with this disease in children. Our findings may help inform public health policy, including the potential of development of early warning systems based on weather factors and PCV for the control and prevention of pneumonia in lower middle-income country like Bangladesh.

Sociodemographic, climatic variability and lower respiratory tract infections: a systematic literature review.

Pneumonia is the leading cause of mortality and morbidity in developing countries, particularly for children and elderly. The main objective of this review paper is to review the epidemiological evidence about the effects of sociodemographic and climatic variability on pneumonia and other lower respiratory tract infections. A detailed literature search was conducted in PubMed and Scopus following PRISMA guidelines. The articles, which considered the effect of only climatic or both climatic and sociodemographic factors on pneumonia and other lower respiratory tract infections, included in this review. A total thirty-four relevant articles were reviewed. Of 34 studies, only 14 articles (41%) examined the joint effects of sociodemographic and climate factors on pneumonia and other lower respiratory infections while most of them (59%) assessed climate factors separately. Among these fourteen, only three articles (8.8%) considered detailed sociodemographic factors. All of the reviewed articles suggested different degrees of positive or negative relationship of temperature with pneumonia or other lower respiratory tract infections. Fifteen (44%) articles suggested an association with relative humidity and 13 (38%) with rainfall. Only 3 articles (8.8%) found a relationship with wind speed. Three articles (8.8%) considered other risk factors such as particulate matter 2.5 (PM2.5) and particulate matter 10 (PM10). One study among the reviewed articles used spatial analysis methods but this study did not examine the joint effects. Among the reviewed articles, 18 (53%) articles used different time series models, one article (3%) used spatiotemporal time series model, 8 (23%) studies used other models and rest 7 (21%) studies used simple descriptive analysis. A total of 18 studies (53%) were conducted in Asia, most of them in China. There were 6 studies (17%) in Europe and 8 studies (23%) in America (South, North and Central). In Africa and Oceania, only one study was found for each region. The joint effect of climate and sociodemographic factors on pneumonia and other lower respiratory tract infections remain to be determined and further research is highly recommended for future prevention of this important and common disease.

The association between ambient temperature and childhood asthma: a systematic review.

The objectives of this study are to review available information on the association between ambient temperature and childhood asthma, and to elucidate the possible underlying mechanisms of this relationship. A systematic review was conducted based on the papers retrieved from four databases, including PubMed, ProQuest, ScienceDirect, and Scopus. Papers examining the association of absolute temperature or temperature variation with childhood asthma published from 1 January 2000 to 31 December 2016 were included. Thirteen papers have quantified the effect of absolute temperature on childhood asthma, and six papers have examined the effect of intra- or inter-day temperature variation on childhood asthma. All studies were conducted in urban areas. Aeroallergen sensitizations were only considered in the analyses of one study. Discrepancy existed in the significance of the relationship between absolute temperature and childhood asthma, and also in the shape of this relationship (i.e. linear or non-linear) and whether temperature effects were lagged. Increasing evidence is suggesting non-linear relationship between absolute temperature and childhood asthma. Future research should investigate the burden of childhood asthma specifically attributable to extreme temperatures and temperature variation using advanced statistical approach, particularly in rural areas, after properly considering aeroallergens and air pollution. Projecting future burden of childhood asthma under climate change scenarios is also warranted.

Anti-Ascaris immunoglobulin E associated with bronchial hyper-reactivity in 9-year-old rural Bangladeshi children.

BACKGROUND: Studies have addressed the immunomodulatory effects of helminths and their protective effects upon asthma. However, anti-Ascaris IgE has been reported to be associated with an increased risk of asthma symptoms. We examined the association between serum levels of anti-Ascaris IgE and bronchial hyper-responsiveness (BHR) in children living in rural Bangladesh. METHODS: Serum anti-Ascaris IgE level was measured and the BHR test done in 158 children aged 9 years selected randomly from a general population of 1705 in the Matlab Health and Demographic Surveillance Area of the International Centre for Diarrhoeal Disease Research, Bangladesh. We investigated wheezing symptoms using a questionnaire from the International Study of Asthma and Allergies in Childhood. BHR tests were successfully done on 152 children (108 'current wheezers'; 44 'never-wheezers'). We examined the association between anti-Ascaris IgE level and wheezing and BHR using multiple logistic regression analyses. RESULTS: Of 108 current-wheezers, 59 were BHR-positive; of 44 never-wheezers, 32 were BHR-negative. Mean anti-Ascaris IgE levels were significantly higher (12.51 UA/ml; 95% confidence interval (CI), 9.21-17.00) in children with current wheezing with BHR-positive than in those of never-wheezers with BHR-negative (3.89; 2.65-5.70; t test, p < 0.001). A BHR-positive test was independently associated with anti-Ascaris IgE levels with an odds ratio (OR) = 7.30 [95% CI, 2.28-23.33], p = 0.001 when adjusted for total IgE, anti-Dermatophagoides pteronyssinus IgE, pneumonia history, parental asthma, Trichuris infection, forced expiratory volume in one second, eosinophilic leukocyte count, and sex. CONCLUSIONS: Anti-Ascaris IgE level is associated with an increased risk of BHR among 9-year-old rural Bangladeshi children.

Arsenic exposure is associated with pediatric pneumonia in rural Bangladesh: a case control study.

BACKGROUND: Pneumonia is the leading cause of death for children under 5 years of age globally, making research on modifiable risk factors for childhood pneumonia important for reducing this disease burden. Millions of children globally are exposed to elevated levels of arsenic in drinking water. However, there is limited data on the association between arsenic exposure and respiratory infections, particularly among pediatric populations. METHODS: This case control study of 153 pneumonia cases and 296 controls 28 days to 59 months of age in rural Bangladesh is the first to assess whether arsenic exposure is a risk factor for pneumonia in a pediatric population. Cases had physician diagnosed World Health Organization defined severe or very severe pneumonia. Urine collected during hospitalization (hospital admission time point) and 30 days later (convalescent time point) from cases and a single specimen from community controls was tested for urinary arsenic by graphite furnace atomic absorption. RESULTS: The odds for pneumonia was nearly double for children with urinary arsenic concentrations higher than the first quartile (≥6 µg/L) at the hospital admission time point (Odd Ratio (OR):1.88 (95% Confidence Interval (CI): 1.01, 3.53)), after adjustment for urinary creatinine, weight for height, breastfeeding, paternal education, age, and number of people in the household. This was consistent with findings at the convalescent time point where the adjusted OR for children with urinary arsenic concentrations greater than the first quartile (≥6 µg/L) was 2.32 (95% CI: 1.33, 4.02). CONCLUSION: We observed a nearly two times higher odds of pneumonia for children with creatinine adjusted urinary arsenic concentrations greater than the first quartile (≥6 µg/L) at the hospital admission time point. This novel finding suggests that low to moderate arsenic exposure may be a risk factor for pneumonia in children under 5 years of age.

Immunization of rabbits with nematode Ascaris lumbricoides antigens induces antibodies cross-reactive to house dust mite Dermatophagoides farinae antigens.

There are controversial reports on the relationship between helminthic infection and allergic diseases. Although IgE cross-reactivity between nematode Ascaris antigens and house dust-mite allergens in allergic patients have been reported, whether Ascaris or the mite is the primary sensitizer remains unknown. Here we found that immunization of naïve animals with Ascaris lumbricoides (Al) antigens induced production of antibodies cross-reactive to mite antigens from Dermatophagoides farinae (Df). Sera from Bangladeshi children showed IgE reactivity to Ascaris and mite extracts. IgG from rabbits immunized with Al extract exhibited reactivity to Df antigens. Treatment of the anti-Al antibody with Df antigen-coupled beads eliminated the reactivity to Df antigens. In immunoblot analysis, an approximately 100-kDa Df band was the most reactive to anti-Al IgG. The present study is the first step towards the establishment of animal models to study the relationship between Ascaris infection and mite-induced allergic diseases.

A mixed method multi-country assessment of barriers to implementing pediatric inpatient care guidelines.

INTRODUCTION: Accelerating progress in reducing child deaths is needed in order to achieve the Sustainable Development Goal child mortality target. This will require a focus on vulnerable children-including young children, those who are undernourished or with acute illnesses requiring hospitalization. Improving adherence to inpatient guidelines may be an important strategy to reduce child mortality, including among the most vulnerable. The aim of our assessment of nine sub-Saharan African and South Asian hospitals was to determine adherence to pediatric inpatient care recommendations, in addition to capacity for and barriers to implementation of guideline-adherent care prior to commencing the Childhood Acute Illness and Nutrition (CHAIN) Cohort study. The CHAIN Cohort study aims to identify modifiable risk factors for poor inpatient and post discharge outcomes above and beyond implementation of guidelines. METHODS: Hospital infrastructure, staffing, durable equipment, and consumable supplies such as medicines and laboratory reagents, were evaluated through observation and key informant interviews. Inpatient medical records of 2-23 month old children were assessed for adherence to national and international guidelines. The records of children with severe acute malnutrition (SAM) were oversampled to reflect the CHAIN study population. Seven core adherence indicators were examined: oximetry and oxygen therapy, fluids, anemia diagnosis and transfusion, antibiotics, malaria testing and antimalarials, nutritional assessment and management, and HIV testing. RESULTS: All sites had facilities and equipment necessary to implement care consistent with World Health Organization and national guidelines. However, stockouts of essential medicines and laboratory reagents were reported to be common at some sites, even though they were mostly present during the assessment visits. Doctor and nurse to patient ratios varied widely. We reviewed the notes of 261 children with admission diagnoses of sepsis (17), malaria (47), pneumonia (70), diarrhea (106), and SAM (119); 115 had multiple diagnoses. Adherence to oxygen therapy, antimalarial, and malnutrition refeeding guidelines was >75%. Appropriate antimicrobials were prescribed for 75% of antibiotic-indicative conditions. However, 20/23 (87%) diarrhea and 20/27 (74%) malaria cases without a documented indication were prescribed antibiotics. Only 23/122 (19%) with hemoglobin levels meeting anemia criteria had recorded anemia diagnoses. HIV test results were infrequently documented even at hospitals with universal screening policies (66/173, 38%). Informants at all sites attributed inconsistent guideline implementation to inadequate staffing. CONCLUSION: Assessed hospitals had the infrastructure and equipment to implement guideline-consistent care. While fluids, appropriate antimalarials and antibiotics, and malnutrition refeeding adherence was comparable to published estimates from low- and high-resource settings, there were inconsistencies in implementation of some other recommendations. Stockouts of essential therapeutics and laboratory reagents were a noted barrier, but facility staff perceived inadequate human resources as the primary constraint to consistent guideline implementation.

Evaluation of Standard and Mobile Health-Supported Clinical Diagnostic Tools for Assessing Dehydration in Patients with Diarrhea in Rural Bangladesh.

Diarrhea remains a leading cause of morbidity and mortality in patients worldwide. The objective of this study was to determine the relative inter-rater reliability and usability of standard and Mobile health (mHealth)-supported World Health Organization (WHO) algorithms for dehydration assessment in patients with acute diarrhea in a rural, low-income country hospital. Two nurses blinded to each other's examinations assessed dehydration status on patients soon after hospital arrival using either the standard WHO algorithm printed on a laminated card or an mHealth-supported WHO algorithm downloaded onto a smartphone. The assignment of assessment tool was based on odd or even enrollment date. The inter-rater reliability for dehydration assessment between the two nurses was calculated using Cohen's K statistic for each study group. A total of 496 patients (< 5 years N = 349, > 5 years N = 147) were enrolled in the study; 132 (27%) had some or severe dehydration, and 364 (73%) had no dehydration on arrival. Cohen's K statistic demonstrated greater reliability for the mHealth-supported dehydration assessment (0.59) compared with the standard assessment (0.50) in the overall population (P < 0.0001), as well as in the pediatric (0.43 versus 0.37, P < 0.0001) and adult (0.79 versus 0.57, P < 0.0001) populations individually. This is the first study to show that mHealth can improve the reliability of nursing dehydration assessment in patients with acute diarrhea and the first to report on the reliability of the WHO algorithm in adult patients specifically. Future studies should focus on the impact of mHealth-supported dehydration assessment on patient-centered outcomes and examine its reliability in different settings worldwide.

Indications and determinants of caesarean section delivery: Evidence from a population-based study in Matlab, Bangladesh.

BACKGROUND AND METHODS: Caesarean section (C-section) is a major obstetric intervention for saving lives of women and their newborns from pregnancy and childbirth related complications. Un-necessary C-sections may have adverse impact upon maternal and neonatal outcomes. In Bangladesh there is paucity of data on clinical indication of C-section at population level. We conducted a retrospective study in icddr,b Health and Demographic Surveillance System (HDSS) area of Matlab to look into the indications and determinants of C-sections. All resident women in HDSS service area who gave birth in 2013 with a known birth outcome, were included in the study. Women who underwent C-section were identified from birth and pregnancy files of HDSS and their indication for C-section were collected reviewing health facility records where the procedure took place, supplemented by face-to-face interview of mothers where data were missing. Indications of C-section were presented as frequency distribution and further divided into different groups following 3 distinct classification systems. Socio-demographic predictors were explored following statistical method of binary logistic regression. FINDINGS: During 2013, facility delivery rate was 84% and population based C-section rate was 35% of all deliveries in icddr,b service area. Of all C-sections, only 1.4% was conducted for Absolute Maternal Indications (AMIs). Major indications of C-sections included: repeat C-section (24%), foetal distress (21%), prolonged labour (16%), oligohydramnios (14%) and post-maturity (13%). More than 80% C-sections were performed in for-profit private facilities. Probability of C-section delivery increased with improved socio-economic status, higher education, lower birth order, higher age, and with more number of Antenatal Care use and presence of bad obstetric history. Eight maternal deaths occurred, of which five were delivered by C-section. CONCLUSIONS: C-section rate in this area was much higher than national average as well as global recommendations. Very few of C-sections were undertaken for AMIs. Routine monitoring of clinical indication of C-section in public and private facilities is needed to ensure rational use of the procedure.

Occurrence of trivalent monomethyl arsenic and other urinary arsenic species in a highly exposed juvenile population in Bangladesh.

Following reports of high cytotoxicity and mutagenicity of monomethyl arsonous acid (MMA(III)) and early reports of urinary MMA(III) in arsenic-exposed individuals, MMA(III) has often been included in population studies. Use of urinary MMA(III) as an indicator of exposure and/or health risk is challenged by inconsistent results from field studies and stability studies, which indicate potential artifacts. We measured urinary arsenic species in children chronically exposed to arsenic in drinking water, using collection, storage, and analysis methods shown to conserve MMA(III). MMA(III) was easily oxidized in sample storage and processing, but recoveries of 80% or better in spiked urine samples were achieved. Attempts to preserve the distribution of MMA between trivalent and pentavalent forms using complexing agents were unsuccessful and MMA(III) spiked into treated urine samples actually showed lower stability than in untreated samples. In 643 urine samples from a highly exposed population from the Matlab district in Bangladesh stored for 3-6 months at ≤-70 °C, MMA(III) was detected in 41 samples, with an estimated median value of 0.3 µg/l, and levels of MMA(III) above 1 µg/l in only two samples. The low urinary concentrations in highly exposed individuals and known difficulties in preserving sample oxidation state indicate that urinary MMA(III) is not suitable for use as an epidemiological biomarker.

Chronic respiratory symptoms in children following in utero and early life exposure to arsenic in drinking water in Bangladesh.

BACKGROUND: Arsenic exposure via drinking water increases the risk of chronic respiratory disease in adults. However, information on pulmonary health effects in children after early life exposure is limited. METHODS: This population-based cohort study set in rural Matlab, Bangladesh, assessed lung function and respiratory symptoms of 650 children aged 7-17 years. Children with in utero and early life arsenic exposure were compared with children exposed to less than 10 µg/l in utero and throughout childhood. Because most children drank the same water as their mother had drunk during pregnancy, we could not assess only in utero or only childhood exposure. RESULTS: Children exposed in utero to more than 500 µg/l of arsenic were more than eight times more likely to report wheezing when not having a cold [odds ratio (OR) = 8.41, 95% confidence interval (CI): 1.66-42.6, P < 0.01] and more than three times more likely to report shortness of breath when walking on level ground (OR = 3.86, 95% CI: 1.09-13.7, P = 0.02) and when walking fast or climbing (OR = 3.19, 95% CI: 1.22-8.32, P < 0.01]. However, there was little evidence of reduced lung function in either exposure category. CONCLUSIONS: Children with high in utero and early life arsenic exposure had marked increases in several chronic respiratory symptoms, which could be due to in utero exposure or to early life exposure, or to both. Our findings suggest that arsenic in water has early pulmonary effects and that respiratory symptoms are a better marker of early life arsenic toxicity than changes in lung function measured by spirometry.