Estimating the full health and economic benefits of current and future influenza vaccines.

In the dynamic landscape of respiratory virus vaccines, it is crucial to assess the value of novel mRNA and combination influenza/COVID-19 vaccines in low- and middle-income countries. Modeling studies, such as the one conducted by Waterlow et al., provide vital information about the cost-benefit potential of these products compared to currently licensed vaccines. However, this approach only accounts for directly measured medically attended influenza-associated illnesses and has two major limitations. First, this method fails to capture the full disease burden of influenza (including non-respiratory and non-medically attended influenza illnesses), which are particularly important drivers of disease burden in infants and older adults. Second, the model does not describe the ancillary benefits of influenza vaccination such as the attenuation of severe disease, prevention of severe non-respiratory outcomes (e.g., myocardial infarctions), or reduced antibiotic use. To obtain a comprehensive understanding of the benefits of influenza vaccines, we must strive to improve the inputs for future modeling-based evaluations.

Raising Backyard Poultry in Rural Bangladesh: Financial and Nutritional Benefits, but Persistent Risky Practices.

Poultry is commonly raised by households in rural Bangladesh. In 2007, the Government of Bangladesh began a mass media campaign to disseminate 10 recommended precautions to prevent transmission of H5N1 from poultry to humans. This longitudinal study explored the contribution of backyard poultry on household economy and nutrition and compared poultry-raising practices to government recommendations. From 2009 to 2012, we enrolled a nationally representative sample of 2489 primary backyard poultry raisers from 115 rural villages selected by probability proportional to population size. Researchers interviewed the raisers to collect data on poultry-raising practices. They followed the raisers for 2-12 months to collect data on household income and nutrition from poultry. Income from backyard poultry flocks accounted for 2.8% of monthly household income. Return on annual investment (ROI) per flock was 480%. Yearly, median family consumption of eggs was one-fifth of the total produced eggs and three poultry from their own flock. Respondents' reported practices conflicted with government recommendations. Sixty per cent of raisers had never heard of avian influenza or 'bird flu'. Among the respondents, 85% handled sick poultry or poultry that died due to illness, and 49% slaughtered or defeathered sick poultry. In 37% of households, children touched poultry. Fifty-eight per cent never washed their hands with soap after handling poultry, while <1% covered their nose and mouth with a cloth when handling poultry. Only 3% reported poultry illness and deaths to local authorities. These reported practices did not improve during the study period. Raising backyard poultry in rural Bangladesh provides important income and nutrition with an excellent ROI. Government recommendations to reduce the risk of avian influenza transmission did not impact the behaviour of poultry producers. Further research should prioritize developing interventions that simultaneously reduce the risk of avian influenza transmission and increase productivity of backyard poultry.

Impact of neighborhood biomass cooking patterns on episodic high indoor particulate matter concentrations in clean fuel homes in Dhaka, Bangladesh.

Exposure to particulate matter (PM2.5 ) from the burning of biomass is associated with increased risk of respiratory disease. In Dhaka, Bangladesh, households that do not burn biomass often still experience high concentrations of PM2.5 , but the sources remain unexplained. We characterized the diurnal variation in the concentrations of PM2.5 in 257 households and compared the risk of experiencing high PM2.5 concentrations in biomass and non-biomass users. Indoor PM2.5 concentrations were estimated every minute over 24 h once a month from April 2009 through April 2010. We found that households that used gas or electricity experienced PM2.5 concentrations exceeding 1000 µg/m(3) for a mean of 35 min within a 24-h period compared with 66 min in biomass-burning households. In both households that used biomass and those that had no obvious source of particulate matter, the probability of PM2.5 exceeding 1000 µg/m(3) were highest during distinct morning, afternoon, and evening periods. In such densely populated settings, indoor pollution in clean fuel households may be determined by biomass used by neighbors, with the highest risk of exposure occurring during cooking periods. Community interventions to reduce biomass use may reduce exposure to high concentrations of PM2.5 in both biomass and non-biomass using households.

Indoor exposure to particulate matter and the incidence of acute lower respiratory infections among children: a birth cohort study in urban Bangladesh.

Approximately half of all children under two years of age in Bangladesh suffer from an acute lower respiratory infection (ALRI) each year. Exposure to indoor biomass smoke has been consistently associated with an increased risk of ALRI in young children. Our aim was to estimate the effect of indoor exposure to particulate matter (PM2.5 ) on the incidence of ALRI among children in a low-income, urban community in Bangladesh. We followed 257 children through two years of age to determine their frequency of ALRI and measured the PM2.5 concentrations in their sleeping space. Poisson regression was used to estimate the association between ALRI and the number of hours per day that PM2.5 concentrations exceeded 100 µg/m(3) , adjusting for known confounders. Each hour that PM2.5 concentrations exceeded 100 µg/m(3) was associated with a 7% increase in incidence of ALRI among children aged 0-11 months (adjusted incidence rate ratio (IRR) 1.07, 95% CI 1.01-1.14), but not in children 12-23 months old (adjusted IRR 1.00, 95% CI 0.92-1.09). Results from this study suggest that reducing indoor PM2.5 exposure could decrease the frequency of ALRI among infants, the children at highest risk of death from these infections.

Influenza-associated excess mortality in southern Brazil, 1980-2008.

In order to estimate influenza-associated excess mortality in southern Brazil, we applied Serfling regression models to monthly mortality data from 1980 to 2008 for pneumonia/influenza- and respiratory/circulatory-coded deaths for all ages and for those aged ≥60 years. According to viral data, 73∙5% of influenza viruses were detected between April and August in southern Brazil. There was no clear influenza season for northern Brazil. In southern Brazil, influenza-associated excess mortality was 1∙4/100,000 for all ages and 9∙2/100,000 person-years for persons aged ≥60 years using underlying pneumonia/influenza-coded deaths and 10∙0/100,000 for all ages and 86∙6/100,000 person-years for persons aged ≥60 years using underlying respiratory/circulatory-coded deaths. Influenza-associated excess mortality rates for southern Brazil are similar to those published for other countries. Our data support the need for continued influenza surveillance to guide vaccination campaigns to age groups most affected by this virus in Brazil.

Prevalent high-risk respiratory hygiene practices in urban and rural Bangladesh.

OBJECTIVES: To identify existing respiratory hygiene risk practices, and guide the development of interventions for improving respiratory hygiene. METHODS: We selected a convenience sample of 80 households and 20 schools in two densely populated communities in Bangladesh, one urban and one rural. We observed and recorded respiratory hygiene events with potential to spread viruses such as coughing, sneezing, spitting and nasal cleaning using a standardized assessment tool. RESULTS: In 907 (81%) of 1122 observed events, households' participants coughed or sneezed into the air (i.e. uncovered), 119 (11%) into their hands and 83 (7%) into their clothing. Twenty-two per cent of women covered their coughs and sneezes compared to 13% of men (OR 2.6, 95% CI 1.6-4.3). Twenty-seven per cent of persons living in households with a reported monthly income of >72.6 US$ covered their coughs or sneezes compared to 13% of persons living in households with lower income (OR 3.2, 95% CI 1.6-6.2). In 956 (85%) of 1126 events, school participants coughed or sneezed into the air and 142 (13%) into their hands. Twenty-seven per cent of coughs/sneezes in rural schools were covered compared to 10% of coughs/sneezes in urban schools (OR 2.3, 95% CI 1.5-3.6). Hand washing was never observed after participants coughed or sneezed into their hands. CONCLUSION: There is an urgent need to develop culturally appropriate, cost-effective and scalable interventions to improve respiratory hygiene practices and to assess their effectiveness in reducing respiratory pathogen transmission.