Type A/H1N1 influenza: a clinical summary of 24 imported cases

Abstract

To study the clinical characteristics and laboratory results of 24 confirmed H1N1 influenza cases. The characters of clinical, laboratory, iconography and etiology of 24 patients with A/H1N1 were studied, and the changes of T-lymphocyte subsets that between the pre- and post-treatment were evaluated. The ages of patients were ranged from 6 to 65 years old; average age was 26 years old.15 patients were under 25 years old. 22 (22/24, 91.7%) patients had recently traveled to USA or Canada. The most common presenting symptoms were: fever (22/24, 91.7%); sore throat (22/24, 91.7%); cough (20/24, 83.3%); dry cough (14/24, 58.3%); expectoration (6/24, 25.0%); nasal discharge (6/24, 25.0%). Six had pneumonia in sixteen patients (6/16, 37.5%) who took CT scan; seven (7/24, 29.2%) had headache and four (4/24, 16.7%) had muscular soreness; two (2/24, 8.3%) had sneeze and nasal obstruction; only one(1/24, 4.2%) had diarrhea; one (1/24, 4.2%) had conjunctivitis. The result of 23 patients about T-Lymphocyte subsets: most of CD4 and CD8 were decreased (18/23, 78.3%), ranging from 122 to 691 cells/microl (normal was 706 - 1125 cells/microl), with the average of 408 cells/microl, but ratios of CD4/CD8 were normal. Fourteen patients were detected CD4 and CD8 after received the treatment during 5 to 7 days.the results of CD4 (cells/microl) were different between the pre- and post-treatment: 436.29 +/- 189.06, 976.71 +/- 332.96 (paired-samples t test: t = -5.416, P < 0.05) while the results of CD8 (cells/microl) were: 323.64 +/- 176.47, 703.14 +/- 211.77 (t = -5.319, P < 0.05); the results of leukocytes in 22 patients were different between pre- and post-treatment: (5.13 +/- 1.47) x 10(9)/L, (6.25 +/- 1.37) x 10(9)/L (t = -2.900, P < 0.05) while the results of lymphocytes were: (1.16 +/- 0.43) x 10(9)/L, (2.30 +/- 0.37) x 10(9)/L (t = -6.819, P < 0.05); but the ratios of CD4/CD8 were: 1.44 +/- 0.41, 1.40 +/- 0.26 (t = 0.507, P > 0.05). All the patients were received antivirus treatment (Oseltamivir) and the virus conversed during 1 - 10 days (average 4.5 days). The temperature was normal after onset during 3 - 4 days and the patients were recovered during 3 - 13 days (with the average of 7.3 days). Influenza A virus H1N1 subtype was identified as the cause of outbreaks of febrile respiratory infection which was self-limited. There was no evidence to show that the changes of T-Lymphocyte subsets could indicate the prognosis of patients.