Analysis on risk factors of influenza A (H1N1)

Objective: We made a retrospective analysis on clinical data of patients with H1N1 influenza diagnosed in our hospital and compared pregnant and puerperal women with H1N1 with other patients with H1N1 for investigating the factors influencing influenza A. Methods: The subjects were 53 cases of patients with influenza A (H1N1) diagnosed in our hospital from May 2009 to March 2010. The following variables/criteria were observed: investigate place of residence, occupation, property status of family, educational level, and frequency of prenatal examination. Blood routine and the liver and renal functions of the mentioned patients were examined, as well as the humoral and cellular immunity indexes of 17 cases of patients with severe influenza A. Ten cases of other patients with mild influenza A (H1N1) were also examined. Results: Among 22 cases of pregnant and puerperal patients with influenza A (H1N1), 10 cases were severe, and 3 cases died. On the contrary, in 31 cases of ordinary patients with influenza A, 7 cases were severe, and 2 of them died. Three cases of dead pregnant patients died of severe pneumonia, whereas 2 cases of other patients with influenza A died of underlying diseases. The morbidity of critically severe patients from the countryside was higher than that of patients from medium or big cities. For different occupations, property statuses of family, and educational levels, there was no significant difference in all groups. CD4 T-lymphocyte count of patients with severe influenza A was higher than that of patients with mild influenza A. Conclusions: It was easier for pregnant and puerperal patients with influenza A than other patients with influenza A to become severe cases. The main reason of death for the former was severe pneumonia. Influence of some factors such as occupation, property status of family, educational level, and other factors on morbidity and mortality of critically severe patients was not clear. CD4 T-lymphocyte count of patients with severe influenza A was higher than that of patients with mild influenza A. Copyright © 2011 by Lippincott Williams & Wilkins.