Influenza A
Are we overreacting to H1N1?
In April 2009, the H1N1 virus (referred to as “Swine Flu”, previously but was later named “Influenza A”) was first detected in people in the United States. Other countries, including Mexico and Canada, have reported people sick with this new virus.
Actually, the scientists who coined the name Influenza A, Swine Flu, or even H1N1 are not accurately naming this virus. This virus is a never-seen-before mixture of four different genetic strains: North American avian flu, human A/H1N1, and swin flu strain found in Asia and Europe.
Steps taken to prevent outbreak.
In this globalised world, different countries seem to be responding differently to the Influenza A outbreak.In the United States, the country with the largest number of cases, there are no thermal scanners at the airports. In Japan, with more than 900 cases, travellers only need to fill a health declaration form.
In Singapore and Malaysia, airports have thermal scanners, hospitals have special tents for suspected cases, quarantine is mandatory and schools have been closed.
Although new, this flu does not appear to be fatal. The World Health Organisation update on 26 June 2009 lists 59,814 confirmed cases with only 263 deaths, giving a mortality rate around 0.5%.
To look at it another way, only 1 out of 200 H1N1 patients will die. That is a lot lower than the death rate of dengue cases.
The recovery rate of H1N1 in Malaysia is also very high. As of 6 July 2009, from the overall 434 confirmed cases. 343 had recovered while 91 are being treated in hospital.
Another interesting finding regarding the H1N1 victims, almost all who died had underlying conditions like asthma or some other respiratory illness before they contracted the H1N1 flu. Their bodies were than too weak to handle the additional viral attack and thus they succumbed to it.
Our response to the flu outbreak may have been inappropriately influenced by the experience with SARS, which had a mortality rate ranging from 15 to 19 per cent. In fact, the American Center for Disease Control (CDC) states that “not all patients with suspected Influenza A need to be seen by a healthcare provider, only patients with severe illness or those at high risk of complications“.
The document (which is at cdc.gov) gives detailed advice on how to care for a patient at home and how to prevent the spread of the virus among members of the same household. Here in Malaysia and Singapore, we quarantine the entire household, forbidding them from even going out for food.
In fact, CDC says that, ‘not all people with suspected Influenza A infection need to have the diagnosis confirmed, especially if the illness is mild‘.
While our policy is to quarantine healthcare workers who may be exposed to suspected Influenza A patients. CDC states that ‘healthcare workers who do not have a febrile respiratory illness may continue to work‘.
The Health Ministry has initiated numerous measures to contain the flu outbreak. Yet patients have expressed unhappiness after experiencing these measures. We are using valuable healthcare resources, both human and material, in this containment policy against the virus.
Should we not treat Influenza A for what it is a new and highly infectious, probably uncomfortable but not at all serious or dangerous for those without underlying illness?
Health authorities are also recommending that Antiviral drugs be taken for the treatment and/or prevention of Influenza A.
According to the CDC, there are four influenza antiviral drugs approved for use in the United States (oseltamivir, zanamivir, amantadine and rimantadine). The H1N1 viruses that have been detected in humans in the United States and Mexico are resistant to amantadine and rimantadine so these drugs will not work against these swine influenza viruses. Laboratory testing on these H1N1 viruses so far indicate that they are susceptible (sensitive) to oseltamivir and zanamivir. Oseltamivir and zanamivir are also known by the brand names Tamiflu and Relenza respectively.
Will the antiviral drug work?
Jose Angel Cordova, the Health Minister of Mexico noted there was no guarantee that getting the anti-viral drug would be of any help against the new strain. After all, Tamiflu and Relanza have been indicated to be effective on only H1N1 which is only one part of Influenza A.
Prominent Malaysian virologist Prof Emeritus Datuk Dr. Lam Sai Kit commented recently in an article entitled ‘Jabs won’t give protection’ found in the 1st May 2009 issue of the New Straits Times commented that the H1N1 strain in the antiviral drug is not going to protect against this mutated strain of influenza. He also mentioned that the indiscriminate use of Tamiflu and Relenza could lead to resistance to the drugs.
Lam, is currently with University of Malaya’s Institute of Research Management and Monitoring. He was also instrumental in the discovery of the Nipah Virus. Lam is also the past President of the Asia-Pacific Society for Medical Virology and also the former director of the WHO’s National Influenza Center (Malaysia).
