CDC: Flu continues decline across the US as influenza B incidence rises
The rate of outpatient visits for influenza-like illnesses (ILI) dropped to 2.7% last week, close to the national baseline of 2.2%, according to the latest influenza surveillance data collected by the Centers for Disease Control and Prevention (CDC). This is the 17th week ILI has been at or above the national baseline.
The CDC also noted that influenza B has now become more common than influenza B, a typical phenomenon late in the flu season. Of all flu viruses typed by public health labs last week, influenza B comprised 57.5%.
The number of states experiencing flu activity is dropping, with only 17 states reporting widespread flu activity and 6 states reporting high ILI rates. Last week, 26 states reported widespread flu, with 12 states reporting high ILI.
Five additional pediatric flu deaths were reported to the CDC, bringing this seasons total to 133.
Though the worst of the season is over, the CDC said flu will still be active for the next several weeks and urged people at risk for flu complications, including pregnant women and the elderly, to visit a healthcare provider if they suspect they have influenza.
"CDC recommends prompt treatment with influenza antiviral medications for people who are severely ill and people who are at high risk of serious flu complications who develop flu symptoms," the CDC said.
Hospitalization rates are still high for adults over the age of 65, at 401.8 per 100,000 people, followed by adults aged 50 to 64 years (101.5 per 100,000), and children aged 0 to 4 years (66.4 per 100,000). The overall hospitalization rate is 93.5 per 100,000.
Mar 23 CDC FluView
Dutch officials report reassortant seasonal flu H1N2 infection
Tests in the Netherlands identified a reassortant H1N2 seasonal flu infection in a toddler who was seen at a clinic that was part of the sentinel surveillance network, Adam Meijer, PhD, on behalf of the Dutch officials who were involved in identifying the virus, wrote yesterday on ProMed Mail, the online reporting system of the International Society for Infectious Diseases.
The 19-month-old boy's symptoms began on Mar 2, and he was taken to a clinic 3 days later. He had not traveled, been vaccinated, or taken antivirals, and had no underlying health conditions. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) and nanopore sequencing confirmed the H1N2 reassortant on Mar 18. After the boy's initial clinic visit, he was seen again on Mar 8 for an ear infection, and he fully recovered after antibiotic treatment.
Investigators found that the boy's parents had experienced gastrointestinal illness 2 weeks before the boy got sick, but no illnesses were reported around that time at the boy's daycare center. Officials stepped up lab monitoring and flu sample typing in the boy's city.
Lab analysis revealed the virus has six gene segments from the H3N2 virus and two from 2009 H1N1. The investigators said they don't expect any increased virulence and didn't see any mutations to suggest resistance to antivirals.
In a comment on the post, ProMED Mail moderator Uzma Bashir, PhD, senior virologist at Pakistan's National Institute of Health, said reassortant seasonal H1N2 viruses have been reported previously. The rise of such a reassortant that contains the 2009 H1N1 virus would be a serious concern, because the 2009 H1N1 virus is well adapted to humans and presents an ideal background for the spread of novel strains. Though there is no sign of spread, Bashir urged labs to remain on alert.
Mar 22 ProMED Mail post
Japan, Europe report more H5N6 detections; H5N1 hits Bhutan poultry
In the latest avian flu outbreak developments, Germany, Japan, and the Netherlands reported new highly pathogenic H5N6 reassortant detections, Bhutan reported more H5N1 in poultry, and Taiwan reported more events involving the H5N2 strain.
In Germany, H5N6 struck a backyard flock of rare and endangered poultry breeds in Schleswig-Holstein state, located in the north, according to a report yesterday from the World Organization for Animal Health (OIE). The facility housed chickens, geese, and ducks. The outbreak began on Mar 20, killing 11 of 73 birds, and survivors were culled. Though the source of the virus hasn't been determined, officials assume it was contact with wild birds.
Meanwhile, Japan and the Netherlands both reported more H5N6 in wild birds. Japan found the virus in 23 large-billed crows found dead between Mar 4 and Mar 14 in the city of Itami in Hyogo prefecture, the OIE said today. In the Netherlands, the H5N6 detections involved a buzzard found on Feb 25 in Zeeland province and a peregrine falcon found dead on Feb 28 in Groningen province.
Mar 22 OIE report on H5N6 in Germany
Mar 23 OIE report on H5N6 in Japan
Mar 23 OIE report on H5N6 in the Netherlands
In outbreaks involving other strains, Bhutan reported its second H5N1 outbreak of the year in poultry, this time involving improved and local birds raised together at a farm in Samtse district in the western part of the country, not far from the Indian border. The outbreak began on Mar 16, killing 323 of 617 birds. The remaining poultry were culled, and the OIE report on the event said the source of the outbreak is illegal movement of animals.
Elsewhere, Taiwan reported six more H5N2 outbreaks, the latest in a series that has been ongoing since 2015. Five of the new outbreaks occurred on commercial farms mainly housing meat ducks and at a slaughterhouse that was processing native chickens. The virus killed 210 of 30,037 birds from Feb 27 to Mar 12, and the remaining ones were destroyed as part of the outbreak response.
Mar 23 OIE report on H5N1 in Bhutan
Mar 23 OIE report on H5N2 in Taiwan