ISMJ

Background: Influenza is a seasonal respiratory illness that affacts all age groups and causes excess mortality annually especially in population with underlying diseases. As Influenza causes seasonal outbreaks and pandemics, knowing clinical finding and complications is very important. Current pandemic of H₁N₁ is associated with some unusual findings such as thrombocytopenia, leukopenia and lymphopenia which is not reported with other types of Influenza. Herein we investigate this hematological manifestations of Influenza patients.

Materials and Methods: This study included all patients who had flu symptoms between 20 November 2015 and 20 January 2016 and were confirmed to have pandemic H₁N₁ influenza infection by polymerase chain reaction from nasopharyngeal specimen method through nasopharyngeal swabs according to National Committee of Influenza. Samples were sent to Kheibar center and then to national influenza references lab in Tehran. CBC and WBC differentiation were requested at the time of admission for evaluation of leukopenia, anemia and thrombocytopenia.

Results: 195 Patients 110 (56.4%) female & 85 (43.6%) with mean age of 46.02 y/o (8-90 years) were enrolled in this study. Mean of WBC was 7.06±3.75×10³/cc which 43.9% of patients were leukopenic. There was no relation between leukopenia with age and sex, but there was a strong relation between positive PCR and underlying diseases.

Mean of platelets were 195×10³/cc and (27.2%) of patients were thrombocytopenic That showed significant association with positive PCR (P-value= 0/012). Half of patients (50%) were anemic without any relation with positive PCR, However showed association with age, sex and underlying conditions.

Conclusion: Thrombocytopenia & leukopenia in associated with severity of illness and underlying medical conditions in influenza patients in H₁N₁ outbreaks.