A. Danielle Iuliano

Preliminary Epidemiology of Human Infections with Highly Pathogenic Avian Influenza A(H7N9) Virus, China, 2017

We compared the characteristics of cases of highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI) A(H7N9) virus infections in China. HPAI A(H7N9) case-patients were more likely to have had exposure to sick and dead poultry in rural areas and were hospitalized earlier than were LPAI A(H7N9) case-patients.

Non-Pharmaceutical Interventions during an Outbreak of 2009 Pandemic Influenza A (H1N1) Virus Infection at a Large Public University, April–May 2009

Nonpharmaceutical interventions (NPIs), such as home isolation, social distancing, and infection control measures, are recommended by public health agencies as strategies to mitigate transmission during influenza pandemics. However, NPI implementation has rarely been studied in large populations. During an outbreak of 2009 Pandemic Influenza A (H1N1) virus infection at a large public university in April 2009, an online survey was conducted among students, faculty, and staff to assess knowledge of and adherence to university-recommended NPI. Although 3924 (65%) of 6049 student respondents and 1057 (74%) of 1401 faculty respondents reported increased use of self-protective NPI, such as hand washing, only 27 (6.4%) of 423 students and 5 (8.6%) of 58 faculty with acute respiratory infection (ARI) reported staying home while ill. Nearly one-half (46%) of student respondents, including 44.7% of those with ARI, attended social events. Results indicate a need for efforts to increase compliance with home isolation and social distancing measures.

Identification of Molecular Markers Associated with Alteration of Receptor-Binding Specificity in a Novel Genotype of Highly Pathogenic Avian Influenza A(H5N1) Viruses Detected in Cambodia in 2013

ABSTRACT Human infections with influenza A(H5N1) virus in Cambodia increased sharply during 2013. Molecular characterization of viruses detected in clinical specimens from human cases revealed the presence of mutations associated with the alteration of receptor-binding specificity (K189R, Q222L) and respiratory droplet transmission in ferrets (N220K with Q222L). Discovery of quasispecies at position 222 (Q/L), in addition to the absence of the mutations in poultry/environmental samples, suggested that the mutations occurred during human infection and did not transmit further.

Investigating 2009 Pandemic Influenza A (H1N1) in US Schools: What Have We Learned?

US investigations of school-based outbreaks of 2009 pandemic influenza A (H1N1) virus infection characterized influenza-like illness (ILI) attack rates, transmission risk factors, and adherence to nonpharmaceutical interventions. We summarize seven school-based investigations conducted during April-June 2009 to determine what questions might be answered by future investigations. Surveys were administered 5-28 days after identification of the outbreaks, and participation rates varied among households (39-86%) and individuals (24-49%). Compared with adults (4%-10%) and children aged <4 years (2%-7%), elementary through university students had higher ILI attack rates (4%-32%). Large gatherings or close contact with sick persons were identified as transmission risk factors. More participants reported adherence to hygiene measures, but fewer reported adherence to isolation measures. Challenges included low participation and delays in survey initiation that potentially introduced bias. Although school-based investigations can increase our understanding of epidemiology and prevention strategy effectiveness, investigators should decide which objectives are most feasible, given timing and design constraints.

Increased Number of Human Cases of Influenza Virus A(H5N1) Infection, Egypt, 2014–15

During November 2014–April 2015, a total of 165 case-patients with influenza virus A(H5N1) infection, including 6 clusters and 51 deaths, were identified in Egypt. Among infected persons, 99% reported poultry exposure: 19% to ill poultry and 35% to dead poultry. Only 1 person reported wearing personal protective equipment while working with poultry.

Detecting Spread of Avian Influenza A(H7N9) Virus Beyond China

This virus is unlikely to have spread substantially among humans in Vietnam, Thailand, Cambodia, and Laos.

Clusters of Human Infection and Human-to-Human Transmission of Avian Influenza A(H7N9) Virus, 2013–2017

To detect changes in human-to-human transmission of influenza A(H7N9) virus, we analyzed characteristics of 40 clusters of case-patients during 5 epidemics in China in 2013–2017. Similarities in number and size of clusters and proportion of clusters with probable human-to-human transmission across all epidemics suggest no change in human-to-human transmission risk.

Estimates of seasonal influenza-associated mortality in Bangladesh, 2010-2012

Seasonal influenza‐associated mortality estimates help identify the burden of disease and assess the value of public health interventions such as annual influenza immunization. Vital registration is limited in Bangladesh making it difficult to estimate seasonal influenza mortality.

Incidence of acute diarrhea-associated death among children < 5 years of age in Bangladesh, 2010-12

Although acute diarrheal deaths have declined globally among children < 5 years, it may still contribute to childhood mortality as an underlying or contributing cause. The aim of this project was to estimate the incidence of acute diarrhea-associated deaths, regardless of primary cause, among children < 5 years in Bangladesh during 2010-12. We conducted a survey in 20 unions (administrative units) within the catchment areas of 10 tertiary hospitals in Bangladesh. Through social networks, our field team identified households where children < 5 years were reported to have died during 2010-12. Trained data collectors interviewed caregivers of the deceased children and recorded illness symptoms, health care seeking, and other information using an abbreviated international verbal autopsy questionnaire. We classified the deceased based upon the presence of diarrhea before death. We identified 880 deaths, of which 36 (4%) died after the development of acute diarrhea, 17 (2%) had diarrhea-only in the illness preceding death, and 19 (53%) had cough or difficulty breathing in addition to diarrhea. The estimated annual incidence of all-cause mortality in the unions < 13.6 km of the tertiary hospitals was 26 (95% confidence interval [CI] 16-37) per 1,000 live births compared with the mortality rate of 37 (95% CI 26-49) per 1,000 live births in the unions located ≥ 13.6 km. Diarrhea contributes to childhood death at a higher proportion than when considering it only as the sole underlying cause of death. These data support the use of interventions aimed at preventing acute diarrhea, especially available vaccinations for common etiologies, such as rotavirus.

Evaluating Hospital-Based Surveillance for Outbreak Detection in Bangladesh: Analysis of Healthcare Utilization Data.

Background The International Health Regulations outline core requirements to ensure the detection of public health threats of international concern. Assessing the capacity of surveillance systems to detect these threats is crucial for evaluating a country’s ability to meet these requirements. Methods and Findings We propose a framework to evaluate the sensitivity and representativeness of hospital-based surveillance and apply it to severe neurological infectious diseases and fatal respiratory infectious diseases in Bangladesh. We identified cases in selected communities within surveillance hospital catchment areas using key informant and house-to-house surveys and ascertained where cases had sought care. We estimated the probability of surveillance detecting different sized outbreaks by distance from the surveillance hospital and compared characteristics of cases identified in the community and cases attending surveillance hospitals. We estimated that surveillance detected 26% (95% CI 18%–33%) of severe neurological disease cases and 18% (95% CI 16%–21%) of fatal respiratory disease cases residing at 10 km distance from a surveillance hospital. Detection probabilities decreased markedly with distance. The probability of detecting small outbreaks (three cases) dropped below 50% at distances greater than 26 km for severe neurological disease and at distances greater than 7 km for fatal respiratory disease. Characteristics of cases attending surveillance hospitals were largely representative of all cases; however, neurological disease cases aged <5 y or from the lowest socioeconomic group and fatal respiratory disease cases aged ≥60 y were underrepresented. Our estimates of outbreak detection rely on suspected cases that attend a surveillance hospital receiving laboratory confirmation of disease and being reported to the surveillance system. The extent to which this occurs will depend on disease characteristics (e.g., severity and symptom specificity) and surveillance resources. Conclusion We present a new approach to evaluating the sensitivity and representativeness of hospital-based surveillance, making it possible to predict its ability to detect emerging threats.