title: Pandemic influenza A (2009 H1N1) in hospitalized patients in a Saudi Arabian hospital: epidemiology and clinical comparison with H1N1-negative patients.
abstract: OBJECTIVE
  The World Health Organization (WHO) declared that pandemic influenza A (H1N1) was a public health emergency of international concern in April 2009. Herein, we describe the characteristics of patients in a Saudi Arabian hospital with and without H1N1 infection.
  
  
  METHODS
  We reviewed the records of patients admitted with influenza-like illness and compared confirmed pandemic H1N1 cases to the H1N1-negative patients admitted to the hospital. Infections due to the novel H1N1 virus were confirmed using real-time reverse transcriptase polymerase chain reaction (rRT-PCR).
  
  
  RESULTS
  During the study period, a total of 165 patients were admitted with influenza-like illness and underwent rRT-PCR testing. Of these patients, 47 (28.4%) had confirmed novel H1N1 virus infection. Thus, the hospitalization incidence rate was 13.4 cases per 100,000 persons. The remaining patients had negative H1N1 rRT-PCR test results. The mean age±SD of the H1N1-positive patients was 30.3±28.5 years compared with 25.3±23 years for the H1N1-negative group (P=0.28). Severe obesity was observed in 6.7% and 8.5% of H1N1-positive and H1N1-negative patients, respectively (P=0.74). The clinical picture was similar between the two groups, except for the higher prevalence of nausea (25.5% vs. 11%) and diarrhea (21.3% vs. 7.6%) in the H1N1-positive group than in the H1N1-negative group (P=0.03) The mortality rate was low in both groups.
  
  
  CONCLUSIONS
  The clinical presentation and outcome are insufficient to differentiate between influenza-like illness (ILI) caused by H1N1 and that cause by other pathogens. In general, both groups had mild disease in this cohort of patients in Saudi Arabia.
authors: Internal Medicine Unit, Saudi Aramco Medical Services Organization, Saudi Aramco, Dhahran, Saudi Arabia.
authors: Jaffar A
authors: JA
authors: Al-Tawfiq
authors: Mahmoud
authors: M
authors: Abed
authors: Bassam M
authors: BM
authors: Saadeh
authors: Jihad
authors: J
authors: Ghandour
authors: Mohammad
authors: M
authors: Shaltaf
authors: Mohamed M
authors: MM
authors: Babiker
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D058873:Pandemics / Q000706:statistics & numerical data*; D011446:Prospective Studies; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012529:Saudi Arabia / Q000453:epidemiology; D055815:Young Adult