ABSTRACT
To assess the epidemiologic and clinical manifestations of the first wave of H1N1 influenza A patients. This study is a retrospective chart review of all patients admitted in King Saud Medical Complex, Riyadh, Kingdom of Saudi Arabia, from 22nd May to 31st August 2009, with a proven diagnosis of H1N1 influenza A. Only patients with a positive nasopharyngeal swab were included, and excluded when the swab was negative. Charts were then analyzed for epidemiological and clinical data. A total of 153 patients with proven H1N1 infection were admitted, with a predominance of male patients [108 [71%]]. Most patients were Saudis [111 [73%]], with 83 males [75%], and 28 females [25%]. The mean age was 25 years [standard deviation; 9.45 years], and median age was 24 years. The most common symptoms in order of frequency were; fever [143 patients], cough [126 patients], sore throat [70 patients], headache [18 patients], shortness of breath [17 patients], myalgia [11 patients], diarrhea [9 patients], and vomiting [7 patients]. Average duration of symptoms before admission was 3.55 days, and the average time of hospitalization was 4.8 days. Full recovery was obtained in 150 patients. Death occurred in 3 patients. True to its designation as a pandemic, H1N1 influenza A, has reached Saudi Arabia and poses a risk to the young population without immunity, and those with co-morbid disease, particularly of the lungs [bronchial asthma], and the pregnant. Despite its virulence in infecting people, deaths are far less than anticipated for such a novel virus. Social distancing can be recommended. However, further observation has to continue to substantiate these tentative preliminary findings