Fatal avian influenza A(H5N1) infection in a 36‐week pregnant woman survived by her newborn in Sóc Trăng Province, Vietnam, 2012

Background Reports of pregnant women infected with avian influenza are rare. Studies showed that A/H5N1 virus can penetrate the placental barrier and infect the fetus. Of six documented cases, four died and two survivors had a spontaneous abortion. Objectives We report a clinical, outcome and epidemiological characteristics of a 36‐week pregnant woman infected with A/H5N1 and her newborn in Soc Trang province of Vietnam in 2012. Methods Epidemiological and laboratory investigations were conducted. Clinical manifestations, progress, treatment and outcome of the case‐patient and her newborn were collected. Human tracheal aspirate, throat swab and serum specimens were tested for influenza A/H5N1, A/H3N1, A/H1N1pdm09 and B by real‐time RT‐PCR and genome sequencing. Poultry throat and rectal swabs were tested by PCR and virus isolation. Results Case‐patient hospitalized with high fever and cough, and died after onset 6 days. She continuously slaughtered sick poultry 5 days before illness onset. Clinical manifestation showed rapid progressive severe pneumonia. Her tracheal aspirate sample was positive influenza A/H5N1 virus. Her new‐born was delivered by caesarean section with low birth weight and early onset pneumonia, however fully recovered after 16 days treatment. Neonate's throat swabs and paired serum samples tested negative for influenza A/H5N1. Clade 1.1 A/H5N1 virus was detected in poultry samples, was same clade and highly homogenous with the virus was detected in the mother. Conclusions This was the first documented a live birth from a pregnant woman infected with influenza A/H5N1 virus. Intensive studies are needed to better understand mother‐to‐child transmission of influenza A/H5N1 virus.