Lethal Avian Influenza A (H5N1) Infection in a Pregnant Woman in Anhui Province, China

Abstract

t0 the editor: On November 2, 2005, fever, chills, and cough developed in a previously healthy woman who was four months pregnant. Chickens and ducks in her household had become ill and had died during October. From October 25 through October 30, the patient had been actively involved in slaughtering and defeathering sick poultry before they were cooked for family consump-tion. She presented to the hospital in Tongling City, China, on November 7 with dyspnea, cyano-sis, a temperature of 38.8°C, a pulse of 118 beats per minute, a respiratory rate of 37 breaths per minute, and an oxygen saturation of 69 percent. Her white-cell count was 4050 per cubic millime-ter, with a lymphocyte count of 608 per cubic mil-limeter. A chest radiograph showed bilateral dif-fuse infiltrates in the lower lobes. Her condition deteriorated despite treatment with azithromy-cin and cefotaxime. She required intubation that evening. The following day, her chest radiograph showed extensive infiltration of both lungs. De-spite intensive supportive care, disseminated in-travascular coagulation and multiorgan failure developed, and she died on November 10. Three tracheal aspirates obtained on Novem-ber 8 tested positive for the H5 strain of avian influenza A virus and for the genes encoding M protein by reverse-transcriptase–polymerase chain reaction (PCR) and by real-time PCR. Influenza A/Anhui/1/2005 virus was isolated from a speci-men of tracheal aspirate. Whole-genome sequenc-ing indicated that all segments were of avian ori-gin. The hemagglutinin-receptor–binding site was similar to those of other avian H5N1 viruses, and a polybasic amino acid cleavage site (LRERRRKRG) was present. Changes in amino acids related to antiviral resistance were not detected in the M-protein or neuraminidase genes. The hemag-glutinin gene sequence was different from that of other H5N1 human isolates (Fig. 1) and was similar to that of influenza A/duck/Fujian/1734/ 2005 (GenBank accession number DQ095629), a clade 2 virus. Other fatal human infections with clade 2 viruses have been identified in China and are genetically related to the isolate in this case (Anhui/2/2005 and Guangxi/1/2005). Women in the second and third trimesters of pregnancy are at increased risk for complica-this week's letters