US flu activity ebbing a bit but still elevated
US flu activity last week showed some signs of decline but continued at an elevated pace, well above epidemic levels, the US Centers for Disease Control and Prevention (CDC) said today in its weekly update.
Of 26,205 specimens tested in the week that ended Jan 17, 5,104 (19.5%) were positive for influenza. That number is down from 20.2% the week before. Geographic spread of flu was reported as widespread in 44 states, compared with 46 the week before.
But the proportion of outpatient visits for influenza-like illness (ILI) was 4.5%, up slightly from 4.4% the week before, and well above the epidemic threshold of 2.0%. ILI levels were reported as high in 23 states, down from 24 states the week before.
Eleven pediatric deaths were confirmed, compared with 19 the week before. Three of the new deaths were attributed to H3N2, by far the most dominant strain, with eight attributed to an influenza A virus that was not subtyped.
The hospitalization rate jumped from 29.9 per 100,000 population in the previous week to 36.3 per 100,000 population last week, which is typical for this point in the season. About 97% of the hospitalizations were caused by influenza A, and 99.7% of those were associated with H3N2.
Of 68,679 samples that have tested positive for flu this season, 65,086 (94.8%) have been influenza A and 3,593 (5.2%) influenza B. Of the 27,870 "A" strains that have been subtyped, 27,752 (99.6%) have been H3N2 and only 118 (0.4%) 2009 H1N1. About 64% of the H3N2 strains do not match the H3N2 component of the vaccine, just slightly lower than reported the week before.
None of the H3N2 strains tested have been resistant to neuraminidase inhibitors, the most common flu antiviral drug, but 1 of 14 2009 H1N1 viruses tested has shown resistance. This is the first report of the season of antiviral resistance.
Jan 23 CDC weekly FluView update
Europe, meanwhile, is seeing increased flu activity, with 15 of 39 countries reporting medium influenza activity, according to an update today from the European Centre for Disease Prevention and Control (ECDC).
The proportion of sentinel specimens testing positive for flu increased from 35% to 40% week to week, with H3N2 predominating. The proportion of influenza-positive specimens was above 10% for the fifth consecutive week, the agency said.
Jan 23 ECDC update
H7N9 sickens 3 people in mainland China, 1 in Hong Kong
Chinese authorities have reported four new H7N9 avian flu cases today, three of which occurred on the Chinese mainland and one that was likely imported from southern China to Hong Kong.
Hong Kong's Centre for Health Protection (CHP) today confirmed H7N9 infection in a 79-year-old man who presented to a clinic with respiratory symptoms on Jan 19 and was hospitalized and isolated in stable condition yesterday. The man traveled to the mainland provinces of Zhangmutou, Dongguan, and Guangdong on Jan 5, where he visited a live-poultry market but had no contact with birds.
The CHP will quarantine and provide antiviral treatment to the case-patient's close contacts and monitor other contacts for symptoms, the agency said in a new release. The case reported today is Hong Kong's second imported case this winter; 12 cases of H7N9 avian flu have been imported to Hong Kong since March 2013.
The CHP also reported three cases of H7N9 on the Chinese mainland today. Two patients are from Guangdong province and involve a 68-year-old man from the city of Shantou who is hospitalized in serious condition and a 4-year-old boy from the city of Zhaoqing who is reported to be in stable condition.
The third case-patient is a 75-year-old woman from Shanghai who is in critical condition and receiving emergency treatment. She is Shanghai's second case of H7N9 avian flu this year, according to Xinhua, China's official news agency.
The four new cases bring the global H7N9 total to 524, according to FluTrackers, an infectious disease news message board.
Jan 23 CHP press release on imported case
Jan 23 CHP press release on mainland cases
Jan 23 Xinhua story
FluTrackers H7N9 case list
Egypt confirms an H5N1 death and new case
Egypt's health ministry reported that a 5-year-old boy from Asyut governorate has died of H5N1 avian flu, according to the Cairo Post today.
The Egyptian Ministry of Health and Population also confirmed a new case of H5N1 in a 60-year-old woman from Gharbia governorate, which is located near the Nile Delta.
Egyptian authorities continue to urge people to take precautions when handling or being near poultry. Of the 25 cases of H5N1 avian flu reported in Egypt this year, 8 people have recovered, 9 are receiving treatment, and 8 people have died, the Cairo Post said.
Jan 23 Cairo Post story