Subclinical Influenza Virus A Infections in Pigs Exhibited at Agricultural Fairs,Ohio, USA, 2009–2011

Agricultural fairs are associated with bidirectional, interspecies transmission of influenza virus A between humans and pigs. We examined pigs exhibited at agricultural fairs in Ohio during 2009–2011 for signs of influenza-like illness and collected nasal swab specimens from a representative subset of these animals. Influenza virus A was recovered from pigs at 12/53 (22.6%) fairs during the 3-year sampling period. Pigs at 10/12 (83.3%) fairs from which influenza virus A was recovered did not show signs of influenza-like illness. Hemagglutinin, neuraminidase, and matrix gene combinations of the isolates were consistent with influenza virus A concurrently circulating among swine herds in the United States. Subclinical influenza virus A infections in pigs at agricultural fairs may pose a risk to human health and create challenges for passive surveillance programs for influenza virus A in swine herds.     

Ebola Virus Disease in Children,Sierra Leone, 2014–2015

Little is known about potentially modifiable factors in Ebola virus disease in children. We undertook a retrospective cohort study of children <13 years old admitted to 11 Ebola holding units in the Western Area, Sierra Leone, during 2014–2015 to identify factors affecting outcome. Primary outcome was death or discharge after transfer to Ebola treatment centers. All 309 Ebola virus–positive children 2 days–12 years old were included; outcomes were available for 282 (91%). Case-fatality was 57%, and 55% of deaths occurred in Ebola holding units. Blood test results showed hypoglycemia and hepatic/renal dysfunction. Death occurred swiftly (median 3 days after admission) and was associated with younger age and diarrhea. Despite triangulation of information from multiple sources, data availability was limited, and we identified no modifiable factors substantially affecting death. In future Ebola virus disease epidemics, robust, rapid data collection is vital to determine effectiveness of interventions for children.     

Influenza epidemiology among hospitalized children in Stockholm,Sweden 1998–2014

BackgroundInfluenza remains a common reason for the hospitalization of children. There is a need for long term studies that are also population based. We describe the epidemiology of severe influenza in a defined population 1998–2014.MethodRetrospective study of annually collected data of virologically confirmed influenza in hospitalized children 0–17 years living in the catchment area (230,000 children). We gathered information about comorbidity and complications from case records, and compared Influenza A, B and A(H1N1)pdm09 with respect to these factors.ResultsA total of 922 children with influenza were hospitalized. The mean rate remained unchanged at 22.5–24.2 per 100,000 children per year. There were two major outbreaks: influenza A(H3N2) in 2003–2004 and the A(H1N1) pandemic in 2009–2010. The proportion of children with influenza B increased from 8% during the first half of the study period to 28% during the second half. The highest admission rate was found in children <3 months of age, 169 per 100,000. Children with influenza B were older than those with influenza A. Comorbidity was found in 34%, complications in 41%, and 11% needed intensive care management. The mortality rate was 0.17/100,000 children.ConclusionInfluenza remains an important reason for the hospitalization of children, especially during the first years of life. The increasing proportion of influenza B may have to be considered when recommending influenza vaccines.     

Transmission Potential of Influenza A(H7N9) Virus,China, 2013–2014

To determine transmission potential of influenza A(H7N9) virus, we used symptom onset data to compare 2 waves of infection in China during 2013–2014. We found evidence of increased transmission potential in the second wave and showed that live bird market closure was significantly less effective in Guangdong than in other regions.     

Schmallenberg Virus Infection among Red Deer,France, 2010–2012

Schmallenberg virus infection is emerging in European domestic and wild ruminants. We investigated the serologic status of 9 red deer populations to describe virus spread from September 2010 through March 2012 among wildlife in France. Deer in 7 populations exhibited seropositivity, with an average seroprevalence of 20%.     

Murine Typhus,Reunion, France, 2011–2013

Murine typhus case was initially identified in Reunion, France, in 2012 in a tourist. Our investigation confirmed 8 autochthonous cases that occurred during January 2011–January 2013 in Reunion. Murine typhus should be considered in local patients and in travelers returning from Reunion who have fevers of unknown origin.     

Heartland Virus Neutralizing Antibodies in Vertebrate Wildlife,United States, 2009–2014

Since its discovery in 2009, the tickborne Heartland virus (HRTV) has caused human illness in Missouri, Oklahoma, and Tennessee USA. To better assess the geographic distribution of HRTV, we used wildlife serology as an indicator. This retrospective evaluation determined that HRTV is widespread within the central and eastern United States.     

Epidemiology of Influenza Virus Types and Subtypes in South Africa, 2009–2012

To determine clinical and epidemiologic differences between influenza caused bydifferent virus types and subtypes, we identified patients and tested specimens.Patients were children and adults hospitalized with confirmed influenza and severeacute respiratory illness (SARI) identified through active, prospective,hospital-based surveillance from 2009–2012 in South Africa. Respiratoryspecimens were tested, typed, and subtyped for influenza virus by PCR. Of 16,005 SARIpatients tested, 1,239 (8%) were positive for influenza virus. Patient age andco-infections varied according to virus type and subtype, but disease severity didnot. Case-patients with influenza B were more likely than patients with influenza Ato be HIV infected. A higher proportion of case-patients infected during the firstwave of the 2009 influenza pandemic were 5–24 years of age (19%) than werepatients infected during the second wave (9%). Although clinical differences exist,treatment recommendations do not differ according to subtype; prevention throughvaccination is recommended.     

Phylogeography of Influenza A(H3N2) Virus in Peru, 2010–2012

It remains unclear whether lineages of influenza A(H3N2) virus can persist in the tropics and seed temperate areas. We used viral gene sequence data sampled from Peru to test this source–sink model for a Latin American country. Viruses were obtained during 2010–2012 from influenza surveillance cohorts in Cusco, Tumbes, Puerto Maldonado, and Lima. Specimens positive for influenza A(H3N2) virus were randomly selected and underwent hemagglutinin sequencing and phylogeographic analyses. Analysis of 389 hemagglutinin sequences from Peru and 2,192 global sequences demonstrated interseasonal extinction of Peruvian lineages. Extensive mixing occurred with global clades, but some spatial structure was observed at all sites; this structure was weakest in Lima and Puerto Maldonado, indicating that these locations may experience greater viral traffic. The broad diversity and co-circulation of many simultaneous lineages of H3N2 virus in Peru suggests that this country should not be overlooked as a potential source for novel pandemic strains.     

Epidemiology of Influenza A Virus among Black-headed Gulls,the Netherlands, 2006–2010

We sampled 7,511 black-headed gulls for influenza virus in the Netherlands during 2006–2010 and found that subtypes H13 and H16 caused annual epidemics in fledglings on colony sites. Our findings validate targeted surveillance of wild waterbirds and clarify underlying factors for influenza virus emergence in other species.     

Influenza A Subtype H3 Viruses in Feral Swine,United States, 2011–2012

To determine whether, and to what extent, influenza A subtype H3 viruses were present in feral swine in the United States, we conducted serologic and virologic surveillance during October 2011–September 2012. These animals were periodically exposed to and infected with A(H3N2) viruses, suggesting they may threaten human and animal health.     

Third Wave of Influenza A(H7N9) Virus from Poultry,Guangdong Province,China, 2014–2015

Fourteen influenza A(H7N9) viruses were isolated from poultry or the environment in live poultry markets in Guangdong Province, China during 2014−2015. Phylogenetic analysis showed that all viruses were descended from viruses of the second wave of influenza A(H7N9) virus infections during 2013. These viruses can be divided into 2 branches.     

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.