Decline in flu activity took a break last week
US influenza activity took a break last week from its recent pattern of steady decline, at least by some measures, the Centers for Disease Control and Prevention (CDC) reported today.
Five states—New York, New Jersey, Delaware, Connecticut, and Massachusetts—reported geographically widespread flu activity last week, compared with four states the week before, the CDC said in its weekly update. And New York City reported high flu-like illness (ILI) activity last week, whereas no jurisdictions had high activity a week earlier.
The share of outpatient medical visits for ILI stayed the same as the week before, at 1.6%, which is well below the national baseline of 2.0%.
The proportion of respiratory specimens that tested positive for flu increased: 12.5% of 5,206 samples last week, up from 11.5% of 4,977 samples a week earlier, the agency said.
Three more flu-related deaths in children were reported, one fewer than the week before, raising the season's total to 82, the CDC said.
The CDC said 6.5% of deaths registered through its mortality reporting system were due to pneumonia and influenza, which was well below the epidemic threshold of 7.3%. A week earlier the figure was 7.2%.
Influenza A/H3N2 and influenza B viruses continued to account for a larger share of cases, near the end of a season in which 2009 H1N1 was mostly predominant. Influenza B accounted for about 52% of viruses that were typed. Of 158 type A viruses that were subtyped, 90 were H3N2 and 68 were H1N1.
The CDC found just one more flu isolate, a 2009 H1N1 virus, showing resistance to oseltamivir (Tamiflu), raising the season's total to 55.
Apr 4 CDC FluView report
H7N9 cases detected in China, Hong Kong
Two new H7N9 illnesses were reported today, one in China and one in Hong Kong in a man who had traveled from China.
The newest case reported from China involves a 62-year-old man from Guangdong province who is hospitalized in critical condition, according to a health department statement translated and posted by FluTrackers, an infectious disease news message board.
Meanwhile, Hong Kong's Centre for Health Protection (CHP) said today that it is investigating an imported H7N9 infection in a 65-year-old man who got sick in the Guangdong city of Shenzhen on Mar 31 and whose symptoms were detected yesterday at an entry point into Hong Kong. The man was immediately hospitalized, and his samples tested positive for H7N9 today. He is isolated in stable condition.
An investigation found that the man had recently bought slaughtered pigeons from a wet market near his home. His illness marks Hong Kong's eighth imported H7N9 case from China.
The two new cases push the outbreak's overall total to 411, according to an ongoing tally of cases kept by FluTrackers. The unofficial number of deaths remains at 124. So far 275 cases have been reported in the outbreak's second wave, compared to 136 in the first wave last spring.
In related developments, the World Health Organization (WHO) today supplied more details about two H7N9 cases reported by China yesterday, in a 28-year-old man from Jiangsu province who is in severe condition and a 68-year-old man from Guangdong who is in critical condition.
Illness onsets were Mar 23 and Mar 20, respectively. Both patients had been exposed to poultry before they got sick.
In poultry-related developments, the United Nations Food and Agriculture Organization (FAO) said yesterday that a recent meeting of experts in late March in Rome started work on creating global guidelines and tools for avian disease surveillance in live poultry markets. They noted that methodologies vary in different countries and that standardization would assist with the evaluation of surveillance systems and help in comparing disease information across borders.
Apr 4 FluTrackers thread
Apr 4 CHP statement
FluTrackers human H7N9 case list
Apr 4 WHO statement
Apr 3 FAO statement