NZ scientists test for deadly flu virus

Scientists in Wellington are testing for a new strain of the influenza virus which has caused six deaths in China.

The World Health Organisation National Influenza Centre (WHO NIC) in Wellington is monitoring the spread of A (H7N9) and planning New Zealand's response.

"There is no sign of the strain in New Zealand, and following the work around the 2009 pandemic, New Zealand also has a very robust response plan in place for any such event in the future," said director of WHO NIC Dr Sue Huang.

"Being part of the WHO network, we are in contact with our international colleagues to learn more about this new strain as well as providing precautionary monitoring for any sign of the virus here," she said.

"As a precaution this laboratory will be investigating samples from any patients with Severe Acute Respiratory Infection that are positive for certain strands of influenza A."

No vaccine is currently available for A (H7N9).

Latest updates show 21 cases of the virus have been laboratory confirmed in China, including six deaths, 12 severe cases and three mild cases.

The cases in China are the first known cases of A (H7N9) infecting humans. It normally circulates among wild birds and poultry.

There is no evidence of ongoing human-to-human transmission, the WHO said on Saturday.

It said more than 530 close contacts of the confirmed cases in China were being closely monitored.

"The Chinese government is actively investigating this event and has heightened disease surveillance. Retrospective testing of recently reported cases with severe respiratory infection may uncover additional cases that were previously unrecognised."

The WHO said it did not advise special screening for A (H7N9) at border points of entry, and it did not recommend any travel or trade restrictions be applied.

Frequently asked questions on A (H7N9)

- What are the main symptoms of human infection with influenza A(H7N9) virus?

Thus far, most patients with this infection have had severe pneumonia. Symptoms include fever, cough and shortness of breath. However, information is still limited about the full spectrum of disease that infection with influenza A(H7N9) virus might cause.

- Why is this virus infecting humans now?

We do not know the answer to this question yet, because we do not know the source of exposure for these human infections. However, analysis of the genes of these viruses suggests that although they have evolved from avian (bird) viruses, they show signs of adaption to growth in mammalian species. These adaptations include an ability to bind to mammalian cells, and to grow at temperatures close to the normal body temperature of mammals (which is lower than that of birds).

- How did people become infected with the influenza A(H7N9) virus?

Some of the confirmed cases had contact with animals or with an animal environment. The virus has been found in a pigeon in a market in Shanghai. It is not yet known how persons became infected. The possibility of animal-to-human transmission is being investigated, as is the possibility of person-to-person transmission.

- Does treatment exist for influenza A(H7N9) infection?

Laboratory testing conducted in China has shown that the influenza A(H7N9) viruses are sensitive to the anti-influenza drugs known as neuraminidase inhibitors (oseltamivir and zanamivir). When these drugs are given early in the course of illness, they have been found to be effective against seasonal influenza virus and influenza A(H5N1) virus infection. However, at this time, there is no experience with the use of these drugs for the treatment of H7N9 infection.

- Is the general population at risk from the influenza A(H7N9) virus?

We do not yet know enough about these infections to determine whether there is a significant risk of community spread.

- Is it safe to travel to China?

The number of cases identified in China is very low. WHO does not advise the application of any travel measures with respect to visitors to China nor to persons leaving China.

Source: World Health Organization


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