Clinical epidemiology comparison of H1N1 RT-PCR-positive and RT-PCR-negative pneumonia during the 2009-2010 pandemic in Mansoura University Hospitals, Egypt

Background Worldwide, the infectivity and disease burden of the H1N1 pandemic were overestimated because of limited clinical experience concerning patient presentation and outcome of those infected with the novel H1N1 virus. Objective This study aimed to compare the epidemiologic clinical data among H1N1 RT-PCR-positive and RT-PCR-negative pneumonic patients during the 2009-2010 pandemic in Mansoura University Hospitals, Egypt. Methods A record-based, case-control study was conducted for 43 adult patients admitted to the chest department isolation unit with community-acquired pneumonia during the 2009-2010 H1N1 pandemic after reviewing of 198 suspected and confirmed H1N1 hospitalized cases. Of these patients, 20 cases were confirmed to be H1N1-positive using an RT-PCR detection technique. The remaining 23 patients were RT-PCR-negative. Demographic, clinical, laboratory and radiological data were collected and analyzed using SPSS version 11. Results A review of 198 hospital case records for revealed one main peak of H1N1 influenza during the last week of December 2009. Pneumonic patients who were H1N1-positive were more likely to present with sore throat (P = 0.005), dyspnea (P = 0.002), and gastrointestinal (GIT) complaints (vomiting and diarrhea P = 0.02) when compared to the H1N1-negative group. Also, complications were significantly more frequent (P = 0.01) in the H1N1-confirmed group than in the non-confirmed group. However, no significant differences were found between the groups regarding length of hospital stay, intensive care unit (ICU), and admission or mortality. Conclusion Sore throat, dyspnea, and presence of GIT complaints increase the suspicion of H1N1 positivity in pneumonia acquired during an H1N1 pandemic. However, H1N1 did not worsen the disease burden of pneumonia.