A study published by the New England Journal of Medicine has said that contributing factor for death in H1N1 patients in Mexico may have been delayed admission and delayed initiation of oseltamivir (Tamiflu).
The study — Pneumonia and respiratory failure from Swine-origin Influenza A (H1N1) virus (S-OIV) in Mexico — however said that the risk factor for severe S-OIV illness are still unknown, but most of the patients were young to middle-aged and had previously been healthy.
“Mortality among the patients requiring mechanical ventilation was 58%, and although four patients had nosocomial pneumonia, in most of the patients, lung damage was most likely due to the primary effect of infection with influenza virus,” the study carried out by experts from the National Institute of Respiratory Diseases (INER) in Mexico city said.
“From March 24 through April 24, 2009, a total of 18 cases of pneumonia and confirmed S-OIV infection were identified among 98 patients hospitalised for acute respiratory illness at the National Institute of Respiratory Diseases in Mexico City. More than half of the 18 case patients were between 13 and 47 years of age, and only eight had pre-existing medical conditions,” the report said.
For 16 of the 18 patients, this was the first hospitalisation for their illness; the other 2 patients were referred from other hospitals.
All patients had fever, cough, dyspnea or respiratory distress, increased serum lactate dehydrogenase levels, and bilateral patchy pneumonia. Other common findings were an increased creatine kinase level (in 62% of patients) and lymphopenia (61%). Twelve patients required mechanical ventilation, and seven died.
Within seven days after contact with the initial case patients, a mild or moderate influenza-like illness developed in 22 health care workers, who were treated with oseltamivir.
The report said S-OIV infection can cause severe illness, primarily acute respiratory distress syndrome, and death in previously healthy persons who are young to middle-aged.
