Monday, October 13, 2008

South African `Mystery Virus' Identified

 

# 2384

 

 

 

For the past week health officials in South Africa have been dealing with a limited outbreak of a `mystery virus', that has claimed at least 3 lives, and has resulted in the isolation of more than 100 exposed people.

 

 

At first, Ebola or one of the other VHF's (Viral hemorrhagic Fevers) was suspected, but the tests for those were negative. 

 

 

Now, according to tests conducted at the Special Pathogens Unit in Johannesburg, the virus has been tentatively identified as a member of the Arenaviridae family

 

 

This is the WHO (World Health Organization) Update on the situation.

 

 

 

New virus from Arenaviridae family in South Africa and Zambia - Update

 

13 October 2008 -- The results of tests conducted at the Special Pathogens Unit, National Institute for Communicable Diseases (NICD) of the National Health Laboratory Service in Johannesburg, and at the Special Pathogens and Infectious Disease Pathology branches of the Centers for Disease Control in Atlanta, USA, provide preliminary evidence that the causative agent of the disease which has resulted in the recent deaths of 3 people from Zambia and South Africa, is a virus from the Arenaviridae family.

 

Analysis continues at the NICD and CDC in order to characterize this virus more fully. CDC and NICD are technical partners in the Global Outbreak Alert and Response Network (GOARN).

 

Meanwhile, a new case has been confirmed by PCR in South Africa. A nurse who had close contact with an earlier case has become ill, and has been admitted to hospital. Contacts have been identified and are being followed-up.

 

WHO and its GOARN partners continue to support the Ministries of Health of the two countries in various facets of the outbreak investigation, including laboratory diagnosis, investigations, active case finding and follow-up of contacts.

 

 

 

 

For an overview of Arenaviridae viruses, we turn to the Special Pathogens Branch of the CDC for some guidance. 

 

These excerpts  from their web page on Arenaviridae

 

 

What are the Arenaviridae?
 

The Arenaviridae are a family of viruses whose members are generally associated with rodent-transmitted disease in humans. Each virus usually is associated with a particular rodent host species in which it is maintained. Arenavirus infections are relatively common in humans in some areas of the world and can cause severe illnesses.

 

What viruses are included in the virus family?
 

The arenaviruses are divided into two groups: the New World or Tacaribe complex and the Old World or LCM/Lassa complex. Viruses in these groups that cause illness in humans are listed below:

 

 

arenaviridae

 

 

 

How are arenaviruses spread?
 

The rodent hosts of arenaviruses are chronically infected with the viruses; however, the viruses do not appear to cause obvious illness in them. 

 

<snip>

 

Human infection with arenaviruses is incidental to the natural cycle of the viruses and occurs when an individual comes into contact with the excretions or materials contaminated with the excretions of an infected rodent, such as ingestion of contaminated food, or by direct contact of abraded or broken skin with rodent excrement. Infection can also occur by inhalation of tiny particles soiled with rodent urine or saliva (aerosol transmission).

 

<snip>

 

Some arenaviruses, such as Lassa and Machupo viruses, are associated with secondary person-to-person and nosocomial (health-care setting) transmission.

 

This occurs when a person infected by exposure to the virus from the rodent host spreads the virus to other humans. This may occur in a variety of ways. Person-to-person transmission is associated with direct contact with the blood or other excretions, containing virus particles, of infected individuals.

 

Airborne transmission has also been reported in connection with certain viruses.

 

Contact with objects contaminated with these materials, such as medical equipment, is also associated with transmission. In these situations, use of protective clothing and disinfection procedures (together called barrier nursing) help prevent further spread of illness.