Sierra Leone: Lassa fever outbreak
 The spread of Lassa fever in refugee camps in southern and eastern Sierra
Leone has been brought under control except in Jimmi Bagbo camp, where severe
cases continue to be registered, the UN High Commission for Refugees (UNHCR)
said.
Lassa fever is an acute viral illness transmitted by rats that is common in
West Africa. It can cause a variety of symptoms, including fever, chest pain,
diarrhea, vomiting and loss of hearing. If untreated, it can result in death.
UNHCR said a campaign was under way to eradicate rats from Jimmi Bagbo in Bo
district, which houses over 6,000 mainly Liberian refugees.
There are nine refugee camps in Sierra Leone housing over 50,000 people.
Between February and April, more than 2,000 suspected cases of Lassa fever were
recorded there.
UNHCR said the campaign to control Lassa fever in the refugee campswas agreed
with several other relief agencies in March and was funded by the European
Commission Humanitarian Office (ECHO).
The disease is transmitted by rodents that live in close proximity to man.
Humans can be infected by inhaling tiny droplets of virus-laden rodent excreta,
eating contaminated food or simply by absorption through the skin.
Even when patients have been treated, the virus remains in their bodies for
six weeks. During this time it can be transmitted through unprotected sex and
sharing food and sanitation facilities, especially in crowded environments like
refugee camps. [IRIN]
What is Lassa fever?
Lassa fever is caused by a virus known as Lassa virus. This animal borne
virus is endemic to certain areas in West Africa including Guinea, Liberia,
Sierra Leone and Nigeria though it may be found in other areas. A rodent known
as the "multimammate rat" , genus Mastomys is the virus host and
readily inhabs homes. Humans can become infected by direct contact with infected
rodents' urine and droppings, or by inhaling particles in the air which have
been contaminated with the animals excretions. The rodents are sometimes
consumed as food, providing a more direct route for infection to humans.
Lassa fever spreads by human to human contact, transmission occurring through
contact with an infected person's blood, tissue, secretions, or excretions of an
individual infected with the Lassa virus.
It is estimated that roughly 100, 000 to 300, 000 people in West Africa are
infected each year with approximately 5000 deaths. The incubation period is 6-21
days. Symptoms include fever, headache, facial swelling, sore throat, cough,
back pain, nausea, vomiting, diarrhoea, mucosal bleeding and chest pain.
Neurological problems such as hearing loss, tremors and encephalitis have also
been observed. Deafness occurs in 25% of patients and only half of these may
recover some hearing function. Approximately 15 - 20 % of people hospitalized
with the illness die, the statistics rising significantly for pregnant women in
the third term of their pregnancy.
Because symptoms are so varied it is difficult to give a diagnosis, however
in the laboratory the fever can be diagnosed using enzyme-linked immunosorbent
serologic assays (ELISA) which detect antibodies and the Lassa antigen.
Lassa fever can be treated with an antiviral drug known as Ribavirin. The
drug appears to be most effective if given in the early stages of illness.
Strategies to control the virus are isolation of infected people, monitoring of
people who may have come into contact with an infected person, hygiene in the
home and of course controlling rodent numbers in and around homes.
More information:
http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/lassaf.htm
http://www.who.int/inf-fs/en/fact179.html
The first part of this article courtesy of IRIN
may not necessarily reflect the views of the United Nations. Copyright (c) UN
Office for the Coordination of Humanitarian Affairs 2003.
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