Objectives: Interpreting real-time reverse transcription-polymerase chain reaction (rRT-PCR) results for human avian influenza A virus (AIV) detection in contaminated settings like live bird markets (LBMs) without serology or viral culture poses a challenge. Methods: During February-March 2012 and November 2012-February 2013, we screened workers at nine LBMs in Dhaka, Bangladesh, to confirm molecular detections of AIV RNA in respiratory specimens with serology. We tested nasopharyngeal (NP) and throat swabs from workers with influenza-like illness (ILI) and NP, throat, and arm swabs from asymptomatic workers for influenza virus by rRT-PCR and sera for seroconversion and antibodies against HPAI A(H5N1) and A(H9N2) viruses. Results: Among 1273 ILI cases, 34 (2.6%) had A(H5), 56 (4%) had A(H9), and six (0.4%) had both A(H5) and A(H9) detected by rRT-PCR. Of 192 asymptomatic workers, A(H5) was detected in eight (4%) NP and 38 (20%) arm swabs. Of 28 ILI cases with A(H5) or A(H9) detected, none had evidence of seroconversion, but one (3.5%) and 12 (43%) were seropositive for A(H5) and A(H9), respectively. Conclusion: Detection of AIV RNA in respiratory specimens from symptomatic and asymptomatic LBM workers without evidence of seroconversion or virus isolation suggests environmental contamination, emphasizing caution in interpreting rRT-PCR results in high viral load settings.
Background Healthcare workers (HCWs) are at increased risk of tuberculosis infection (TBI). We estimated the prevalence and incidence of TBI and risk factors among HCWs in Bangladeshi hospitals to target TB infection prevention and control (IPC) interventions. Methods During 2013–2016, we conducted a longitudinal study among HCWs in four chest disease hospitals. At baseline, we administered a questionnaire on sociodemographic and occupational factors for TB, tuberculin skin tests (TST) in all hospitals, and QuantiFERON ®-TB Gold in-Tube (QFT-GIT) tests in one hospital. We assessed factors associated with baseline TST positivity (induration ≥10mm), TST conversion (induration increase ≥10mm from baseline), baseline QFT-GIT positivity (interferon-gamma ≥0.35 IU/mL), and QFT-GIT conversion (interferon-gamma <0.35 IU/mL to ≥0.35 IU/mL). We included factors with a biologically plausible relationship with TBI identified in prior studies or having an association (p = <0.20) in the bivariate analyses with TST positivity or QFT-GIT positivity in multivariable generalized linear models. The Kaplan-Meier was used to estimate the cumulative TBI incidence rate per 100 person-years. Results Of the 758 HCWs invited, 732 (97%) consented to participate and 731 completed the one-step TST, 40% had a positive TST result, and 48% had a positive QFT-GIT result. In multivariable models, HCWs years of service 11–20 years had 2.1 (95% CI: 1.5–3.0) times higher odds of being TST-positive and 1.6 (95% CI 1.1–2.5) times higher odds of QFT-GIT-positivity at baseline compared with those working ≤10 years. HCWs working 11–20 years in pulmonary TB ward had 2.0 (95% CI: 1.4–2.9) times higher odds of TST positivity, and those >20 years had 2.5 (95% CI: 1.3–4.9) times higher odds of QFT-GIT-positivity at baseline compared with those working <10 years. TBI incidence was 4.8/100 person-years by TST and 4.2/100 person-years by QFT-GIT. Females had 8.5 (95% CI: 1.5–49.5) times higher odds of TST conversion than males. Conclusions Prevalent TST and QFT-GIT positivity was associated with an increased number of years working as a healthcare worker and in pulmonary TB wards. The incidence of TBI among HCWs suggests ongoing TB exposure in these facilities and an urgent need for improved TB IPC in chest disease hospitals in Bangladesh.
We assessed the relationship of fecal environmental contamination and environmental enteropathy. We compared markers of environmental enteropathy, parasite burden, and growth in 119 Bangladeshi children (≤ 48 months of age) across rural Bangladesh living in different levels of household environmental cleanliness defined by objective indicators of water quality and sanitary and hand-washing infrastructure. Adjusted for potential confounding characteristics, children from clean households had 0.54 SDs (95% confidence interval [CI] = 0.06, 1.01) higher height-for-age z scores (HAZs), 0.32 SDs (95% CI = −0.72, 0.08) lower lactulose:mannitol (L:M) ratios in urine, and 0.24 SDs (95% CI = −0.63, 0.16) lower immunoglobulin G endotoxin core antibody (IgG EndoCAb) titers than children from contaminated households. After adjusting for age and sex, a 1-unit increase in the ln L:M was associated with a 0.33 SDs decrease in HAZ (95% CI = −0.62, −0.05). These results are consistent with the hypothesis that environmental contamination causes growth faltering mediated through environmental enteropathy.
During September 2009, we performed a rapid cross-sectional study to investigate the extent of aflatoxin contamination among common Bangladeshi foods. We collected eight common human food commodities (rice, lentils, wheat flour, dates, betelnut, red chili powder, ginger and groundnuts) and poultry feed samples from two large markets in each of three cities in Bangladesh. We quantified aflatoxin levels from pooled subsamples using fluorescence high-performance liquid chromatography. Aflatoxin levels were highest in dates and groundnuts (maximum 623 and 423 ng/g), respectively. Samples of betelnut (mean 30.6 ng/g), lentils (mean 21.2 ng/g) and red chili powder (> 20 ng/g) also had elevated levels. The mean aflatoxin level among poultry feed samples was 73.0 ng/g. Aflatoxin levels were above the US maximum regulatory levels of 20 ng/g in five of eight commonly ingested human food commodities tested.
Aflatoxin contamination in food commodities in Bangladesh Monika Roy a , Julie Harris a , Sadia Afreen b , Eszter Deak a , Lalitha Gade a , S. Arunmozhi Balajee a , Benjamin Park a , Tom Chiller a & Stephen Luby a b a Centers for Disease Control and Prevention, Mycotic Diseases Branch, Atlanta, GA, USA b International Centre for Diarrhoeal Disease Research, Bangladesh Accepted author version posted online: 14 Aug 2012.Published online: 18 Sep 2012.