Youths, healthy adults at riskWASHINGTON - ADOLESCENTS and relatively healthy adults are especially at risk from the H1N1 flu, which is associated with respiratory failure and a high mortality rate in serious cases, studies said on Monday.
The studies, conducted during the first phase of infection between March 18 and June 1 in Mexico and April 16 through Aug 12 in Canada, also show how emergency services were sometimes submerged by the number of serious cases that needed to be treated simultaneously.
Serious cases of infection from the influenza A(H1N1) virus in patients in Mexico were all linked to severe acute respiratory distress syndrome, followed by a state of shock with a high incidence of death.
At least 4,525 people have died from H1N1 flu infections since April and there have been over 378,223 laboratory-confirmed cases, the World Health Organisation said Friday, with most deaths occurring in the Americas.
Of the 899 patients admitted to six Mexican hospitals with confirmed or probable A(H1N1) infections during the period studied, 58 were in serious condition, the study's authors said. The median age of critically ill patients was 44.
Most were treated with antibiotics and 45 of them with the antivirals Tamiflu or Relenza, while 54 required an artificial respirator. Among the 58 serious cases, 24 (41.4 percent) died within 60 days of hospitalisation, including 19 during the first two weeks. -- AFP