"Guess What" Deadly H7N9 virus develops drug-resistance to Tamiflu

"Guess What" Deadly H7N9 virus develops drug-resistance to Tamiflu. (YourHealth).

TAIPEI, Taiwan - The only H7N9 patient so far in Taiwan was carrying two strains of the same virus, with one being drug resistant and the other not, making it tricky to treat to him, doctors said.

Huang Li-min, a doctor from National Taiwan University Hospital (NTUH), explained that it was possible the avian flu virus was not drug resistant when the patient was first infected, but mutated later to become resistant to Tamiflu. 
With Tamiflu failing, NTUH later switched to another intravenous drug, Huang said. Because of the presence of the two strains simultaneously, it was difficult for doctors to determine how much the virus’ drug resistance had undermined the therapy Chou Chi-hao, deputy director-general of the Centers for Disease Control (CDC), said it is natural for viruses to mutate, saying the H1N1 flu strain mutated after infecting human beings.
But Huang said H7N9 has limited chances of human-to-human transmission through respiratory secretions because the virus has difficulty surviving the environments of human upper respiratory systems. Patients do not have symptoms of a runny nose or sneezing.
The patient, surnamed Lee, got sick on April 12, three days after returning from a business trip in China. His condition was initially critical, but has improved much. He has already been transferred from the intensive care unit to an ordinary ward at NTUH. The findings by the NTUH and CDC about H7N9 are to be published in a local medical journal next month. Resistance is of concern in the scenario of an influenza pandemic (Wong and Yuen 2005), and may be more likely to develop in avian influenza than seasonal influenza due to the potentially longer duration of infection by novel viruses.Read the full story here.

US invokes emergency act to keep H7N9 flu at bay.

US invokes emergency act to keep H7N9 flu at bay.(NS).

THE US government has declared that H7N9 bird flu "poses a significant potential for a public health emergency", and has given "emergency use authorisation" for diagnostic kits for the virus. This means tests can be used that haven't gone through the usual lengthy approval process by the US Food and Drug Administration.

They are right to be concerned. H7N9 could be a tough adversary: New Scientist has learned that it provokes a weaker immune response than most flu, making vaccines hard to produce.

Although H7N9 is not, so far, transmissible between humans, it does cause severe disease in people, is easier to catch than other bird flu strains, and may need only a few mutations to go pandemic. The UK has already given doctors instructions on when to test people for H7N9, and how to manage any with the virus.

The US's emergency authorisation will allow the use of a kit that looks for flu genes using a polymerase chain reaction test, which has been made specific for H7N9. The kit has had preliminary tests but would normally need more exhaustive tests to be approved. Innovative new diagnostics should eventually be authorised too, says Charles Chiu of the University of California in San Francisco.

This kind of fast, high-throughput screening for pandemic flu, possibly at borders, might allow early cases to be treated with antiviral drugs, potentially slowing the spread of the virus while vaccines are made.

The next emergency authorisation is likely to be for immune-stimulating chemicals called adjuvants to put in those vaccines. These were used in vaccines in Europe and Canada during the 2009 pandemic, but adjuvants suitable for flu are not currently approved in the US.

Labs are now making "seed" viruses for manufacturers to create H7N9 vaccine. That process faces the same development delays as in 2009, when vaccine arrived too late for most people.

But there is another problem: H7 flu is poor at stimulating immunity. Virologists at the European Flu Summit in Brussels last week told New Scientist that early results show 13 times more H7N9 virus is needed to elicit a protective immune response than is needed for ordinary flu. That's bad news: the more virus a vaccine requires, the fewer doses that can be grown in a given time.

"H7N9 may be a 'stealth' virus that is able to fly under the immune system's radar," says Anne De Groot of the University of Rhode Island at Providence. That's because its surface protein haemagglutinin doesn't contain many short amino acid sequences – called epitopes – that trigger helper T-cells in the body to stimulate antibody-making cells.

"H7N9 is not very immunogenic, because the epitopes have a very weak signal," says Masato Tashiro, head of flu at Japan's National Institute of Infectious Diseases in Tokyo. People differ genetically in the epitopes their T-cells recognise, and his lab has found that Asian people could be especially vulnerable.Read the full story here.

China reports 4 more H7N9 infections bringing total to 7, two confirmed dead.

China reports 4 more H7N9 infections bringing total to 7, two confirmed dead.(Cidrap).By Lisa Schnirring.Chinese health officials today reported that the H7N9 influenza virus has been detected in four more people, all in critical condition, raising the number of patients infected with the new strain to seven.

All of the patients are from Jiangsu province, an area on China's eastern coast that borders the city of Shanghai and Anhui province, the two areas that reported the first three H7N9 cases, which included the deaths of two men from Shanghai.

A statement today from the Jiangsu Province Health Department, identified and translated this morning by the Avian Flu Diary blog, said all four patients—three women and a man—are in critical condition at hospitals in Nanjing, Wujiang, and Wuxi.

One is a 45-year-old woman from Jiangning district who worked as a poultry slaughterer. She became ill with a fever, body aches, and other symptoms on Mar 19 and was hospitalized on Mar 27. The second patient, a 48-year-old woman from the city of Suqian who is a sheet metal worker, got sick with similar symptoms on Mar 19 and was hospitalized on Mar 30.

The man who was infected is an 83-year-old resident of Suzhou Wujiang district who came down with a fever and respiratory symptoms on Mar 20 and was hospitalized on Mar 29. The fourth patient is a 32-year-old woman from the city of Wuxi who is unemployed. She started having a cough, fever, and other symptoms on Mar 21 and was hospitalized on Mar 28.

The Jiangsu Provincial Center for Disease Control and Prevention detected the H7N9 virus in samples from the patients, and tests at China's Center for Disease Control and Prevention (China CDC) lab confirmed the results for the first two cases. Yesterday Chinese health officials said the source of the infections is probably poultry. The H7N9 virus has previously infected only birds, though other H7 subtypes have been known to infect humans, typically causing conjunctivitis and mild respiratory symptoms.

In another statement today, the CHP said it activated Hong Kong's pandemic alert response level, which triggers certain surveillance and control measures. The alert level is the lowest response category. The next level is serious, and the highest is the emergency level.

The World Health Organization (WHO) today published a frequently-asked-questions resource about H7N9 on its Web page, which emphasized that so far health officials have found no evidence of human-to-human spread, though investigators are exploring all possible sources. "The risk associated with A (H7N9) avian influenza virus to the general population in China and beyond is being investigated and will be shared to the public when information becomes available," the WHO said. Read the full story here.

H1N1 cases in Saudi Arabia kept silent to avoid panic among haj pilgrims.

H1N1 cases in Saudi Arabia kept silent  to avoid panic among haj pilgrims.(GD).Riyadh, Saudi Arabia (4E) – Saudi health authorities reported at least eight cases of H1N1 infections at the Al-Amal mental hospital in Riyadh.
The infected people were given Tamiflu vaccine while 27 other people, including four nurses, suspected of having the influenza virus were quarantined. Staff of the hospital also took precautionary measures, including wearing masks when dealing with patients, and cancelling an party celebrating the Eid al-Adha Muslim festival.

The latest H1N1 outbreak in the kingdom was discovered 18 days ago but was not disclosed to avoid panic among haj pilgrims according to spokesman of Health Affairs Directorate in Riyadh Saad Al Qahtani. 

The virus first reached Saudi Arabia in 2009 brought by an infected Filipino nurse working at King Faisal Specialized Hospital. Last month, a Saudi boy vacationing with his family in Hong Kong was diagnosed with the virus but recovered. In September, a 60-year-old Saudi man died from the virus and a 49-year-old Qatari man was infected with it after traveling to the kingdom. The Qatari man has recovered after being treated in a hospital in London.Read the full story here.

Related: Novel coronavirus Saudi Arabia, third case confirmed A third case of novel coronavirus infection causing severe respiratory illness has been confirmed in Saudi Arabia.

Related: A Saudi man cured of SARS.