A study of an influenza A (H1N1)pdm09 outbreak in pregnant women in Rajasthan, India.

ABSTRACT

OBJECTIVES: To describe the clinical and epidemiological factors of influenza A (H1N1)pdm09-infected patients who were pregnant or in the puerperal period during a recent influenza outbreak in Rajasthan, India. METHODS: A retrospective, observational study was performed using hospital records of individuals with confirmed influenza A (H1N1)pdm09 infection admitted to a large tertiary care center in Rajasthan, India, between January 1 and March 15, 2015. RESULTS: The study cohort included 44 patients who were pregnant or in the puerperal period. The mean age was significantly lower in the study cohort than in other female patients treated for influenza A (H1N1)pdm09 infection at the hospital during the study period (25.45±3.45years vs 40.46±13.99 years; P<0.001). Mortality was significantly higher in the study cohort than in the comparison female patients (36% vs 17%; P=0.003). Factors found to be associated with mortality were delayed initiation of oseltamivir, poor oxygen saturation at admission, and more than 50% lung involvement under radiographic examination. None of the patients in the study cohort had received a vaccination against seasonal influenza. CONCLUSION: Influenza A (H1N1)pdm09 infection during pregnancy causes more severe illness. Early recognition and timely administration of antiviral therapy can improve outcomes. The role of influenza vaccination in this high-risk population cannot be overemphasized.