H1N1 (Swine Flu): Pregnant Women, Danger Signs of H1N1 and the “new” H3N2
Increased risk for pregnant women
Lancet just published (July 29, 2009) research conducted in the USA drawing further attention to the increased risk of severe or fatal illness in pregnant women when infected with the H1N1 pandemic virus. Several other countries experiencing widespread transmission of the pandemic virus have similarly reported an increased risk in pregnant women, particularly during the second and third trimesters of pregnancy. An increased risk of fetal death or spontaneous abortions in infected women has also been reported. WHO strongly recommends that, in areas where infection with the H1N1 virus is widespread, pregnant women, and the clinicians treating them, be alert to symptoms of influenza-like illness.
Treatment with Antivirals
Treatment with the antiviral drug oseltamivir (Tamiflu) should be administered as soon as possible after symptom onset. As the benefits of oseltamivir are greatest when administered within 48 hours after symptom onset, clinicians should initiate treatment immediately and not wait for the results of laboratory tests
Danger signs in all patients
Worldwide, the majority of patients infected with the pandemic virus continue to experience mild symptoms and recover fully within a week, even in the absence of any medical treatment. Monitoring of viruses from multiple outbreaks has detected no evidence of change in the ability of the virus to spread or to cause severe illness.
In addition to the enhanced risk documented in pregnant women, groups at increased risk of severe or fatal illness include people with underlying medical conditions, most notably chronic lung disease (including asthma), cardiovascular disease, diabetes, and immunosuppression. Some preliminary studies suggest that obesity, and especially extreme obesity, may be a risk factor for more severe disease.
Within this largely reassuring picture, a small number of otherwise healthy people, usually under the age of 50 years, experience very rapid progression to severe and often fatal illness, characterized by severe pneumonia that destroys the lung tissue, and the failure of multiple organs. No factors that can predict this pattern of severe disease have yet been identified, though studies are under way.
Clinicians, patients, and those providing home-based care need to be alert to danger signs that can signal progression to more severe disease. As progression can be very rapid, medical attention should be sought when any of the following danger signs appear in a person with confirmed or suspected H1N1 infection:
- Shortness of breath, either during physical activity or while resting
- Difficulty in breathing
- Turning blue
- Bloody or colored sputum
- Chest pain
- Altered mental status
- High fever that persists beyond 3 days
- Low blood pressure.
In children, danger signs include fast or difficult breathing, lack of alertness, difficulty in waking up, and little or no desire to play.
The “new” H3N2 brings new Influenza Threat
Hong Kong’s health authorities announced July 27 that a new variant of the H3N2 seasonal influenza virus has been found in the city. The Brisbane strain has been the prevalent circulator of H3N2 in the past year, and the new variant is its direct descendent, said Thomas Tsang, controller of Hong Kong’s Center for Health Protection (CHP). According to the CHP, H3N2 accounts for 43 percent of flu viruses circulating in Hong Kong, while A/H1N1 accounts for 49 percent. This “new” version has been reported in Canada, Britain and Australia.
As reported in our blog last week, the 2009/2010 northern hemisphere seasonal flu vaccine may not be a direct match for this new variant however it will still provide some protection against it.
PRO> ProMED Digest V2009 #362 – www.promedmail.org