H7N9

 

Avian influenza A H7 viruses are a group of influenza viruses that normally circulate among birds. The avian influenza A(H7N9) virus is one subgroup among the larger group of H7 viruses. “H7N9” is the designation for one subtype of influenza viruses that is sometimes found in birds, but that does not normally infect humans. An H7N9 virus was first reported to have infected humans in 2013 in China. The Chinese Public Health authorities reported the first human cases of disease due to the infection with a type A influenza virus of the strain H7N9. This strain of virus usually infects birds, and the report was followed by reinforced surveillance in bird populations in China.

 

Main symptoms of influenza A(H7N9)virus

 

Thus far, most patients with this infection have had severe pneumonia. Symptoms include:

1) Fever

 

2) Cough

 

3) Shortness of breath

 

4) Severe pneumonia

 

5) Acute respiratory distress syndrome (ARDS)

 

6) Septic shock

 

7) Multi-organ failure leading to death.

 

How are people becoming infected with the avian influenza A(H7N9) virus ?

 

At this point it is not known how persons are becoming infected. Some of the confirmed cases had contact with animals or with environments where animals are housed. The virus has now been found in chickens, ducks, and captive-bred pigeons at live bird markets near locations where cases have been reported. The possibility of an animal source of the infection is being investigated, as is the possibility of person-to-person transmission. Chinese health authorities are investigating this situation very carefully. They are following up on close contacts of infected people to find out if they have gotten infected. This is important to find out whether there has been person-to-person spread of this virus. So far, hundreds of close contacts have been checked and there has not been any evidence of ongoing spread of this virus from person-to-person.

 

How can infection with avian influenza A(H7N9) virus be prevented ?

 

Although both the source of infection and the mode of transmission are uncertain, it is prudent to follow basic hygienic practices to prevent infection. They include hand and respiratory hygiene and food safety measures.

Hand Hygiene

 

Wash your hands before, during, and after you prepare food; before you eat; after you use the toilet; after handling animals or animal waste; when your hands are dirty; and when providing care when someone in your home is sick. Hand hygiene will also prevent the transmission of infections to yourself (from touching contaminated surfaces) and in hospitals to patients, health care workers and others.Wash your hands with soap and running water when hands are visibly dirty; if hands are not visibly dirty, wash them with soap and water or use an alcohol-based hand cleanser.

Respiratory Hygiene

Cover your mouth and nose with a medical mask, tissue, or a sleeve or flexed elbow when coughing or sneezing; throw the used tissue into a closed bin immediately after use; perform hand hygiene after contact with respiratory secretions.Wash your hands with soap and running water when hands are visibly dirty; if hands are not visibly dirty, wash them with soap and water or use an alcohol-based hand cleanser.

 

Does treatment exist for avian influenza A(H7N9) infection ?

 

When influenza antiviral drugs known as neuraminidase inhibitors are given early in the course of illness, they are effective against seasonal influenza virus and influenza A(H5N1) virus infection. At this time, there is little experience with the use of these drugs for the treatment of H7N9 infection. Further, influenza viruses can become resistant to these drugs.