Tweet
Archive Number 20111020.3132
Published Date 20-OCT-2011
Subject PRO/AH/EDR> Rift Valley fever, human - France: ex Zimbabwe (ME) 1st
RIFT VALLEY FEVER, HUMAN - FRANCE: ex ZIMBABWE (MASHONALAND EAST)
FIRST REPORT
************************************************** ****************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
Date: Wed 19 Oct 2011
From: Guillaume Vesin <guillaume.vesin@chu-bordeaux.fr> [edited]
A 21 year old Caucasian traveller returning from Zimbabwe, where she
visited the rural region of Marondera [Mashonaland East province] from
17 Jul to 11 Aug 2011, was seen in our department on 5 Sep 2011 for
major asthenia and violent headache. She acknowledged that the next
day after return she experienced fever that resolved within a week.
Laboratory investigations for malaria, Lyme disease, rickettsiosis,
dengue, chikungunya, and West Nile fever viruses were all negative
whereas Rift Valley fever virus serology using Elisa testing was
positive for IgM.
On 17 Oct 2011 she is still complaining of headache although no
relapse in fever was noted. To the best of our knowledge, this is the
1st report of human Rift Valley fever from Zimbabwe.
--
Guillaume Vesin
<guillaume.vesin@chu-bordeaux.fr>
Dr Receveur, Pr Malvy
Service de medecine tropicale
CHU de Bordeaux
France
[ProMED-mail thanks Guillaume Vesin for forwarding this interesting
account of the detection of the 1st known human case of Rift Valley
fever virus (RVFV) infection in Zimbabwe.
Rift Valley fever (RVF), a mosquitoborne zoonotic disease among humans
and ruminants, is caused by Rift Valley fever virus, a virus belonging
to the family _Bunyaviridae_, genus _Phlebovirus_. RVF is endemic to
sub-Saharan African countries and has caused major outbreaks in
several countries including Kenya, Tanzania, Somalia, South Africa,
Madagascar, Egypt, Sudan, Mauritania, Senegal, Saudi Arabia, and
Yemen. Pregnant ruminants infected with RVFV typically are subject to
high-rate abortions, fetal malformation, and subclinical-to-fatal
febrile illness, while newborn lambs usually die by acute hepatitis.
RVFV infection in humans primarily causes a self-limiting febrile
illness; however, some patients develop haemorrhagic fever,
neurological disorders, or blindness after the febrile period. In
endemic areas, _Aedes_ mosquitoes, such as _Ae. mcintoshi_ or _Ae.
vexans_ serve as vectors, and the virus can be transmitted into
offspring transovarially. Heavy rainfall or flooding of river banks
due to construction of dams increases the number of permanent fresh
water species of mosquitoes such as _Culex pipiens_, which play a role
in amplifying RVFV among mosquitoes, ruminants, and humans (see
Ikegami T, Makino S. The pathogenesis of Rift Valley fever. Viruses.
2011; 3(5): 493-5;
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3111045/>).
The vast majority of human infections result from direct or indirect
contact with the blood or organs of infected animals. The virus can be
transmitted to humans through the handling of animal tissue during
slaughtering or butchering, assisting with animal births, conducting
veterinary procedures, or from the disposal of carcasses or fetuses.
The aerosol mode of transmission has also led to infection in
laboratory workers. There is some evidence that humans may also become
infected with RVFV by ingesting the unpasteurized or uncooked milk of
infected animals. To date, no human-to-human transmission of RVF has
been documented, and no transmission of RVF to health care workers has
been reported when standard infection control precautions have been
put in place (see
<http://www.who.int/mediacentre/factsheets/fs207/en/index.html>).
Although the human case described above may be the 1st record of human
infection in Zimbabwe, phylogenetic analyses of RVF viruses isolated
in Zimbabwe has revealed the presence of multiple virus lineages
indicating that the spread of distinct RVF virus genotypes is an
ongoing process and can occur over large geographic distances (see
Bird, et al. J Virol. 2007 March; 81(6): 2805-16;
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1865992>).
Marondera is a town and district in Mashonaland East, Zimbabwe,
situated about 72 km (45 mi) east of the capital Harare. It can be
located in the HealthMap/ProMED-mail interactive map of Zimbabwe at
<http://healthmap.org/r/1m1w>. - Mod.CP]
Comment