Interpersonal distributionOf the first 87 cases ŸAge range = 2~87y, median = 63y, elder people more common, only 3 child cases with milder clinical presentations M:F = 2.4:1 Occupational exposure to birds in at least 19 cases, retired people account for 44 cases, none HCW It was said that most fatal cases were male smokers
Suspect clusters1) Shanghai Li’s family 55y son became ill on 11th Feb, with severe pneumonia, died on 28th Feb, no sample collected for H7N9 testing 87y father became ill on 19th Feb, with severe pneumonia, died on 4th Mar, H7N9 PCR positive 69y son became ill on 19th Feb, with milder clinical course, H7N9 PCR negative, retrospective serological test positive
Suspect clusters2) Jiangsu Zhang’s family 32y daughter became ill on 21st Mar, H7N9 PCR positive Her father had been ill before, H7N9 tests negative
Suspect clusters3) Shanghai Gu’s family 52y wife became ill on 27th Mar, died on 3rd Apr, H7N9 PCR positive 56y husband became ill on 1st Apr, H7N9 PCR positive
Hypothetical mixing of avian flu viruses from east Asiamigratory birds and east China ducks and chickens.
Animal and environment testing Since 20th Mar, animal facilities around human cases in Anhui, Jiangsu and Shanghai had been checked, with no animal illness found. Until 3rd Apr, agricultural departments of Shanghai, Jiangsu, Zhejiang, and Anhui did not have specific testing agents for H7N9.
Animal and environment testing As of 16th Apr, provincial and national AI reference laboratories had collected a total of 84444 samples, covering 473 live poultry markets, 32 slaughterhouses, 896 farms, 79 wild bird habitats, 36 pig slaughterhouses, and 137 environmental sampling spots. Tests for 47801 samples had been concluded, yielding only 39 positive results (0.05%), of which 38 were poultry and environment samples from live markets of Shanghai, Anhui, Zhejiang and Jiangsu, 1 was from wild pigeon from Nanjing, Jiangsu.
Negative tests Date Location Sample quantity Tests04.02 Shanghai natural Migratory and wild birds 229 H7 gene preservation district and zoos~04.09 Shanghai farms Animals 366 AI common PCR04.01~04.11 Farms, parks, wild bird Chickens, pigs, ducks, 5609 ? habitats and supermarkets gooses, pigeons, crows, in 16 districts of Beijing wild birds, animal products04.14 Gucheng villange in Beijing Poultry 61+ Virology+ 95 SerologyEnd of Mar 35 pig farms and 11 pig Pigs 2050+ Virology+~04.17 slaughterhouses in 2000 Serology Shanghai, Anhui, Zhejiang, and Jiangsu
Ducks along the bank of Changjiang river may be all infectedSource of H7N9 virus may be the migratory birdsin Changjiang river mouth
H7N9 continuously evolves, hard to predict risk The virus is still searching for a more compatible combination
Risk assessment1. The reassortment of avian influenza viruses had occurred, probably in East China2. The reassorted virus massively go across the animal-human boundary to infect human3. The virus is low pathogenic for birds and highly pathogenic for human4. Up to the moment, there is no evidence that the virus further go across the boundary to sustained human- to-human transmission, though limited human-to- human transmission can not be excluded
Phase 1 Phase 2 Phase 3 Bird-to-bird transmission Bird-to-human transmission & Widespread limited human-to-human transmission human-to-human transmission H7N9 H1~H16Avian disease surveillance, Minimizing human exposure Ensuring care for patientsprevention and control Detection and isolation of Slowing down spread human cases
Risk assessment5. It is probably that the virus spreads beyond East China to Central and North China by migratory birds, which infect local Poultry and the latter infect human6. Comparing with H5N1, H7N9 infection in poultry seems more widespread and persistent, constituting a greater threat for human7. At this moment, it is impossible to precisely predict if the virus will come to Macao, or how (birds or human?), but preparedness is necessary
Animal-animal line of defense Separate poultry with migratory birds and wild birds Separate water fowls and land fowls Separate poultry from different regions Separate infected poultry with other poultry
Significant measures taken in Macao All local poultry farms eliminated Raising poultry prohibited Importation of live water fowls prohibited Management in the source, surveillance, separation, and double quarantine for poultry provided from inland to Macao Culling of all live poultry before the live markets close everyday
Animal-human line of defense Biosafety measures for poultry industry. In case of animal epidemic, handling infected poultry under strict protection General people avoiding contact with live poultry or presenting in places with live poultry, washing hands after contact with raw poultry meat or egg, eating poultry meat or eggs thoroughly cooked According to situational, government adopting appropriate risk management measures in sites for poultry wholesale, sale, or watching
Human-human line of defense Raising people’s alert for prompt seeking medical advice if severe acute respiratory illness develops Raising HCW alert, strengthening surveillance system, building laboratory capacity, testing acute respiratory patients with travel, poultry or patient contact history, and patients with pneumonia of unknown cause, for early detection of cases Strengthening infection control in medical facilities. Early isolation and treatment of detected cases Tracing and health management of close contacts of cases