Study reports person-to-person spread of H7N9 in family
Aug 06, 2013
A young Chinese woman most likely caught the H7N9 avian influenza virus from her father after caring for him in the hospital, marking the first probable case of human-to-human transmission, according to a report released today in BMJ.
The daughter got sick only after prolonged, close contact with her father, and no cases were found in other family members or in healthcare workers. The authors therefore conclude that the virus has not gained the capability for efficient, sustained transmission.
Although the virus didn’t spread further, the transmission event “means there is potential for greater human to human transmission,” says the report. It was written by a large Chinese team, with Xian Qi as first author.
The father, a 60-year-old retiree, was in charge of buying food for his extended family, and he occasionally visited live poultry markets, according to the report. In early March he bought six quail at one of the markets and cooked them. On Mar 8 he fell ill with a fever, cough, and shortness of breath, and he was hospitalized on Mar 11.
He was treated with antibiotics, but on Mar 15 he was moved to the hospital’s intensive care unit because of respiratory distress. Three days later he was moved to the ICU of a tertiary hospital and treated with oseltamivir. He died of multiple organ failure on May 4.
The man’s 32-year-old daughter was healthy and had no known exposure to poultry before her illness. She cared for her father before he was hospitalized and for several days after he entered the hospital. Her father had “abundant expectoration” starting on Mar 14, and, without wearing protective equipment, she cleaned his secretions and maintained his oral hygiene until he entered the ICU.
The young woman fell ill with a fever and cough on Mar 21, six days after her last contact with her father. She was treated with antibiotics and later with oseltamivir, but on Mar 28 she was moved to an ICU and put on a ventilator. On Apr 4 she died of multiple organ failure and cardiac arrest.
Both patients tested positive for the H7N9 virus in late March. When viral isolates from both of them were sequenced, they were found to be nearly identical (99.6% to 99.9% match) but slightly different from an H7N9 virus found at one of the poultry markets visited by the father.