Avian Flu: New Strain Responsible for Chinese Woman’s Death

A new type of bird-flu has been identified as the cause of death for an elderly woman in China. A medical team in China has reported the avian influenza A H10N8 virus caused human infection for the patient in Nanchang City, China. After studying the case, a medical team published their findings, and a discussion of the case in The Lancet. ”The pandemic potential of this novel virus should not be underestimated,” the team concluded.

H10 or N8 subtype viruses commonly circulate among birds, but H10N8 has never been documented in humans. In 2004, H10N7 was reported in Egypt, and it emerged in Australia in 2010. “The first human infection with novel avian influenza An H10N8 virus further increases the importance of surveillance for pandemic preparedness and response,” the team stated.

The Centers for Disease Control and Prevention explain that influenza A viruses are divided into subtypes based on the proteins existing on the virus’ surface. There are 17 hemagglutinin (or, HA) and 10 neuraminidase (or, NA) subtypes, resulting in many combinations. Avian flu is then further classified as highly pathogenic or low pathogenic; this describes the virus’ ability to cause severe disease.

The patient was a 73-year-old woman who had previous medical conditions including hypertension, coronary heart disease, and myasthenia gravis. The latter is a chronic condition, which causes muscles to easily tire and become weak. On November 27, 2013, she developed symptoms including chest tightness and a cough. On the 30th, she was admitted to the hospital with a fever of 38.6 degrees Celsius (101.48 degrees Fahrenheit.) Her fever eventually reached 39.4 degrees Celsius, or 102.92 degrees Fahrenheit.

It was noted that four days before her symptoms began, the woman visited a live poultry market. However, she did not handle any of the chickens, and when the birds were tested for the H10N8 virus, there were no matches. If this did originate at a poultry market, the incubation period of four days is consistent with previous bird-flu outbreaks, the team noted.

During the patient’s stay in the hospital, her condition rapidly deteriorated. On day seven, the patient’s blood work indicated kidney and liver failure. The patient received a “combination antibiotic treatment for prevention of bacterial infection, mechanical ventilation, glucocorticoids, intravenous albumin, and antiviral treatment,” which did not arrest the viruses progress. Severe pneumonia developed, as well as septic shock, and multiple organ failure. On December 6, day nine of the illness, the patient died.

Since none of the samples from the poultry market in Chongqing tested matched the H10 and N8 subtype viruses, which were overwhelmingly present in the patient, medical officials cannot determine the source of infection. Another case of human infection with H10N8 was reported in Nanchang City on Jan 26, 2014. The seventeen people who came in close contact with the patient in the first, fatal case have so far not shown any symptoms. There is also hope the virus can be treated. Test results demonstrated it is susceptible to antiviral drugs oseltamivir (Tamiflu), and zanamivir (Relenza).

The medical team credited China’s flu surveillance system for its ability to detect “novel influenza viruses causing human infection as early as possible.” The systems in place in China to prepare for a pandemic include “hospital-based surveillance systems for influenza-like illness and severe acute respiratory illness, the laboratory-based influenza virological surveillance system, and the surveillance system for pneumonia of unknown aetiology that is based in clinical institutions.” All of this is crucial according to the report’s authors, for quickly identifying novel influenza viruses in humans.