LASSA FEVER - WEST AFRICA (17): NIGERIA

Posted on 14TH MAY 2017
tagged Lassa Fever, West Africa; Nigeria

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: Tue 2 May 2017
Source: Outbreak News Today [edited]
http://outbreaknewstoday.com/nigeria-lassa-outbreak-death-toll-now-68-92...

In a follow-up on the Lassa fever outbreak affecting several states in Nigeria, the Nigeria Centre for Disease Control (NCDC) reports 68 Lassa fatalities since the outbreak began in mid-December 2016 through 28 April [2017].

In the current Lassa Fever outbreak, 16 States (Ogun, Bauchi, Plateau, Ebonyi, Ondo, Edo, Taraba, Nasarawa, Rivers, Kaduna, Gombe, Cross-River, Borno, Kano, Kogi and Enugu) have reported at least one confirmed case.

However, as of the end of April [2017], Lassa is still active in 9 states-Bauchi, Ondo, Edo, Taraba, Nasarawa, Kaduna, Kano, Kogi and Enugu.

In total, 164 Lassa cases have been reported with 149 cases being confirmed.

According to the US Centers for Disease Control and Prevention (CDC), Lassa fever is an acute viral illness that occurs in West Africa. The virus, a member of the virus family Arenaviridae, is a single-stranded RNA virus and is zoonotic, or animal-born.

Lassa fever is a significant cause of morbidity and mortality. While Lassa fever is mild or has no observable symptoms in about 80 percent of people infected with the virus, the remaining 20 percent have a severe multisystem disease.

The animal host of Lassa virus is a rodent known as the "multimammate rat" of the genus _Mastomys_. Humans get infected with Lassa through aerosol or direct contact with excreta from the rodent. Laboratory infections do occur, primarily through contaminated needles.

The symptoms of Lassa fever typically occur 1-3 weeks after the patient comes into contact with the virus. These include fever, retrosternal pain (pain behind the chest wall), sore throat, back pain, cough, abdominal pain, vomiting, diarrhea, conjunctivitis, facial swelling, proteinuria (protein in the urine), and mucosal bleeding. Neurological problems have also been described, including hearing loss, tremors, and encephalitis.

The Lassa virus was 1st described in 1969 in the town of Lassa, in Borno State, Nigeria.

[Byline: Robert Herriman]

--
Communicated by:
ProMED-mail from HealthMap Alerts

[It is not surprising that cases of Lassa fever are continuing to occur in Nigeria. As noted in earlier comments, Lassa fever remains a problem in Nigeria because the virus is endemic there. Virus transmission to humans occur when people are in contact with the reservoir rodent host, the multimammate mouse (in the genus _Mastomys_) or their excreta. Transmission also occurs in health facilities when personal protection equipment is not employed and barrier nursing practices are not adequate to protect staff from blood and secretions of infected patients.

Also, as noted in earlier, prevention and control of Lassa fever in nature depends on control of the rodent reservoir, which occurs across Nigeria and beyond. Reduction of populations of this rodent will require active participation at the village level. That will necessitate mounting a public education program with support of rodent control technicians. Preventing entry of rodents into the home and keeping food materials tightly covered are helpful measures to prevent infection. Elimination of these rodents completely is probably not possible.

Images of _Mastomys_ mice can be seen at http://www.ispot.org.za/node/255877.

Maps of Nigeria can be accessed at http://www.un.org/Depts/Cartographic/map/profile/nigeria.pdf and http://healthmap.org/promed/p/62. - Mod.TY

This report was also sent in by ProMED-mail Rapporteur Kunihiko Iizuka, who we thanked.

A HealthMap/ProMED-mail map can be accessed at: http://healthmap.org/promed/p/62.]

See Also

Lassa fever - West Africa (16): Nigeria (BA) 20170412.4967018
Lassa fever - West Africa (15): Nigeria (KO) 20170404.4947996
Lassa fever - West Africa (14): Nigeria 20170402.4943005
Lassa fever - West Africa (13): update 20170328.4931422
Lassa fever - West Africa (12): Nigeria 20170327.4929174
Lassa fever - West Africa (11): Nigeria 20170319.4911462
Lassa fever - West Africa (10): Benin, Togo, Burkina Faso 20170312.4896305
Lassa fever - West Africa (09): Nigeria (BO) 20170302.4875164
Lassa fever - West Africa (08): Benin 20170301.4872702
Lassa fever - West Africa (07): Nigeria (BA) 20170225.4864837
Lassa fever - West Africa (06): Nigeria 20170225.4862689
Lassa fever - West Africa (05): Nigeria (NA) 20170215.4842179
Lassa fever - West Africa (04): Liberia 20170209.4827934
Lassa fever - West Africa (03): Nigeria (RI) 20170122.4782917
Lassa fever - West Africa (02): Nigeria (NA) 20170118.4773375
Lassa fever - West Africa (01): Nigeria (OG) 20170101.4735363
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