Difference between H1N1 and regular flu becoming clearer

Deaths in children from H1N1 have already claimed twice the typical number of victims for an entire flu season. A WHO symposium addressing the management of pandemic influenza confirms the ability of the new H1N1 virus to directly cause severe pneumonia. In severe cases, patients can progress to respiratory failure within 24 hours. 30% of these cases are complicated by secondary bacterial infections, some of which are antibiotic resistant. “Prompt treatment with the antiviral drugs, oseltamivir or zanamivir, reduces the severity of illness and improves the chances of survival. These findings strengthen previous WHO recommendations for early treatment with these drugs for patients who meet treatment criteria, even in the absence of a positive confirmatory test.”

http://www.who.int/csr/disease/swineflu/notes/h1n1_clinical_features_20091016/en/index.html

Participants who have managed such cases agreed that the clinical picture in severe cases is strikingly different from the disease pattern seen during epidemics of seasonal influenza. While people with certain underlying medical conditions, including pregnancy, are known to be at increased risk, many severe cases occur in previously healthy young people. In these patients, predisposing factors that increase the risk of severe illness are not presently understood, though research is under way.

In severe cases, patients generally begin to deteriorate around 3 to 5 days after symptom onset. Deterioration is rapid, with many patients progressing to respiratory failure within 24 hours, requiring immediate admission to an intensive care unit. Upon admission, most patients need immediate respiratory support with mechanical ventilation.

Participants agreed that the risk of severe or fatal illness is highest in three groups: pregnant women, especially during the third trimester of pregnancy, children younger than 2 years of age, and people with chronic lung disease, including asthma. Neurological disorders can increase the risk of severe disease in children.

http://hosted.ap.org/dynamic/stories/U/US_MED_SWINE_FLU?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2009-10-17-12-07-17

Eighty-six children have died of swine flu in the U.S. since it burst on the scene last spring - 43 of those deaths reported in September and early October alone, said Schuchat.

That's a startling number because in some past winters, the CDC has counted 40 or 50 child deaths for the entire flu season, she said, and no one knows how long this swine flu outbreak will last.