Transmission electron micrograph of the H5N1 avian flu virus Imaged by Cynthia Goldsmith/ Jackie Katz

Troubling reports have emerged from China in the last few weeks of a new strain of influenza (H7N9) that could be the Next Big One.  The internet is predictably alive with information, forecasts, and statistics, not all of which are true.

Pay attention, don’t bother. Freak out, don’t cancel that trip. Panic, stay calm.

What is all the fuss about? Most importantly, whom should you listen to?

See below for a list of sources, as well as an aggregation of information on the virus (only from these sources).

H7N9 facts at a glance (updated on April 16th)

(This section will be continually updated)
Source: Virology Down Under, CDC

Total confirmed cases of influenza virus A H7N9 in humans: 77

Number of human deaths caused by the virus: 16

Locations of the infections (# of cases): Shanghai (30), Jiangsu (20), Anhui (3), Zhejiang (21), Henan (2), Beijing (1)

Cases of bird flu have been found in five live bird markets in Eastern China

According to the WHO, has there been person-to-person spread?

  • NO

According to the WHO, are any of the cases linked to each other?

  • NO

Preliminary tests indicate these two drugs could be effective for patients: neuraminidase inhibitors, oseltamivir and zanamivir

Are there any travel restrictions to China at this time (April 16, 2013)?

H7N9 is an influenza A virus, so its natural reservoir is a bird, but it can subsequently affect many other animals

Has H7N9 previously infected any human anywhere?

  • No, it has only been isolated in birds, but those cases were from Japan and the US as well

The CDC has released a great explanation of what to worry about in terms of transmission of this virus.  Included is evidence on previous avian influenzas that have not transmitted from person to person very far from the original infected individual. Repeated monitoring of individuals that have come into contact with people with the infection has resulted in no subsequent cases of infection thus far.

History of the infection

March, 2013: People begin to show up ill at hospitals in China

April 1, 2013: WhO receives reports of 3 human infections from China

April 4, 2013: China reports that closely related strains of the virus have been found in pigeons at a market in Shanghai

April 5, 2013: First mass culling of all birds in the market where the infected pigeons were discovered

April 6, 2013: China suspends the sale of live poultry

April 8, 2013: China grounds 60,000 carrier pigeons and gives them vaccines against a different type of bird flu. All pigeon races are now called off.

April 10, 2013: H7N9 is found in a few ducks and chickens in Jiangsu, Zhejiang and Anhui in China. Some samples are similar to the pigeon virus from April 4, 2013. Also, the first patient is discharged from a hospital, allegedly recovering from the infection – he is 4 years old, and is being touted as the first victim to be cured of the infection. Finally, China launches an official research program into creating a vaccine.

April 11, 2013: A Chinese lab identifies a mixture of DNA from wild birds from East Asia and chickens from east China in the virus. None of the DNA belongs to pigs.

April 12, 2013: All 31 provinces in China are now equipped with the ability to test for H7N9. All WHO Collaborating Centers have received virus isolates from patients in China ( WHO’s Head of Media posts on Twitter).

April 13, 2013: An assessment of migratory birds is conducted in the hopes of discovering an intermediary or a source of the infection.  Beijing reports its first case of the virus.

April 14, 2013: 507 birds killed in Beijing after the 7-year old daughter of a poultry farmer is infected.  Neither of her parents is sick.  Luckily, her condition looks like it is improving.

What about a vaccine?

No vaccine is available at this time.

However, the sequences for the first three viruses have been decoded, and China has made them available to other labs interested in contributing to the search for a vaccine.

The vaccine is expected to be ready in 7 months, say the Ministry of Science and Technology and the National Health and Family Planning Commission.

CIDRAP assesses a recent article in the New England Journal of Medicine on the first three cases of infection, and concludes that the H7 viruses are difficult to create vaccines for.

Relevant (but not light) reading on the progress of the disease:

The Chinese Center for Disease Control and Prevention’s FAQs on H7N9. Note: this might not reflect day-to-day numbers

A full report on all influenza cases of H5N1 virus in 2012 was just released by the WHO.

Spillover (by David Quammen), because it will scare the pants off you, but is still a riveting read on all things zoonotic.

Current and reliable information on H7N9:

Maryn McKenna is the author of Superbug, an in-depth look at the convoluted and fascinating history of MRSA (multi-drug resistant Staphylococcus aureus). Scroll down for her list of reliable places to get your information, reproduced here faithfully, or read the original article here.


Helen Branswell of the Canadian Press

Declan Butler of Nature

Martin Enserink of Science

Lisa Schnirring and Robert Roos at CIDRAP.

Mara Hvistendahl of Science, if she covers this, as she is based in Shanghai.


Crawford Kilian (@crof)

Mike Coston (@Fla_Medic)

Crowdsourced data

HealthMap, a huge Harvard- and Google-backed effort that combines Web-scraping with human review (also on Twitter, as is their blog editor Anna Tomasulo and their founderJohn Brownstein)

FluTrackers, a volunteer, civilian effort that has been going since the H5N1 days.

Media on the ground

Xinhua, China Daily, South China Morning Post (in Hong Kong, somewhat more free to report).

Official sources

WHO, China CDC, European CDC and its journal, EuroSurveilance, US CDC, OIE