[Relation between clinical detection rates of the novel influenza virus A/H1N1 RNA in confirmed patients in Guangzhou and the disease course].

Objective: To study the relation of the detection rates of the novel influenza virus A/H1N1 RNA in clinically confirmed patients in the 2009 pandemic with the age distribution of the patients and the disease course.

Methods: A total of 151 clinical patients with H1N1 infection were enrolled in this study, from whom 833 dynamic throat swab samples were obtained for detecting the H1N1 RNA using real-time PCR. A statistical analysis of the age distribution was performed among the patients with different disease courses. Chi-square for trend test was used to study the correlation between the detection rates of H1N1 RNA and the time of disease onset.

Results: The majority of patients were young with their ages ranging from 10 to 20 years (57.26%) and 20 to 30 years (22.18%). Chi-square for trend test revealed that the positivity rates of the throat swabs in the patients decreased with the prolongation of the disease course (chi(2)=9.784, P=0.002).

Conclusion: Most of the H1N1 patients are young within the age range of 10-30 years, and the longest disease course can exceed 10 days. The positivity rates of throat swabs from the H1N1 patients decreases with the prolongation of the disease course.