LASSA FEVER - WEST AFRICA (18): NIGERIA

Posted on 30TH 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: Fri 19 May 2017
Source: Nigeria Centre for Disease Control Weekly Epidemiological Report 7 (18) [edited]
http://www.ncdc.gov.ng/reports/46/2017-may-week-18

1. Lassa fever
Please note that the data reflect the routine reports -- that is, all suspected cases including the laboratory positive and negative cases.

1.1. Eleven suspected cases of Lassa fever were reported from 3 LGAs ([local government areas] (2 states) in week 18 of 2017 compared with 3 suspected cases from 3 LGAs (3 states) during the same period in 2016.

1.2. Laboratory results of the 11 suspected cases are pending (Edo - 10 and Taraba - 1).

1.3. Between weeks 1 and 18 (2017), 255 suspected Lassa fever cases with 58 laboratory confirmed cases and 46 deaths (case fatality rate [CFR] 18 per cent) from 51 LGAs (20 states) were reported compared with 657 suspected cases with 63 laboratory confirmed cases and 75 deaths (CFR 11.4 per cent) from 122 LGAs (27 states) during the same period in 2016 (figure 1).

1.4. Throughout 2016, 921 suspected Lassa fever cases with 109 laboratory confirmed cases and 119 deaths (CFR 12.9 per cent) from 144 LGAs (28 states and Federal Capital Territory [FCT]) were reported compared with 430 suspected cases with 25 laboratory confirmed cases and 40 deaths (CFR 9.3 per cent) from 37 LGAs (14 states and FCT) during the same period in 2015 (figure 2).

1.5. Investigation and active case search is ongoing in affected states with coordination of response activities by the Nigeria Centre for Disease Control [NCDC] with support from partners.

1.5.1. National Lassa Fever Working Group meetings and weekly National Surveillance and Outbreak Response meetings continue at NCDC to keep abreast of the current Lassa fever situation in the country.

1.5.2. Response materials for VHFs prepositioned across the country by NCDC at the beginning of the dry season.

1.5.3. New viral haemorrhagic fever [VHF] guidelines have been developed by the NCDC: interim national viral haemorrhagic fevers preparedness guidelines and standard operating procedures for Lassa fever management.

1.5.4. Ongoing reclassification of reported Lassa fever cases.

1.5.5. Ongoing review of the variables for case-based surveillance for VHF.

1.5.6. VHF case-based forms completed by affected states are being entered into the new VHF management system. This system allows for the creation of a VHF database for the country.

1.5.7. Confirmed cases are being treated at identified treatment/isolation centres across the states with Ribavirin and necessary supportive management also instituted.

1.5.8. Onsite support was earlier provided to Ogun, Nasarawa, Taraba, Ondo and Borno States by the NCDC and partners.

1.5.9. Offsite support provided by NCDC/partners in all affected states.

1.5.10. States are enjoined to intensify surveillance.

Figure 1: Map of Nigeria showing areas affected by Lassa fever, week 1- 18, 2016 & 2017
and
Figure 2: Map of Nigeria showing areas affected by Lassa fever, week 1 - 53, 2015 and week 1 - 52, 2016
are available at the source URL above.

Table of cases by state, cumulative data weeks 1-18:
State: Cases / Lab Confirmed / Deaths
Adamawa: 6 / 0 / 2
Bauchi: 9 / 3 / 3
Cross River: 3 / 0 / 0
Ebonyi: 4 / 1 / 1
Edo: 91 / 20 / 9
Enugu: 1 / 1 / 1
FCT: 2 / 0 / 0
Gombe: 15 / 0 / 1
Jigawa: 1 / 0 / 0
Kadun: 1 / 0 / 0
Kano: 23 / 2 / 10
Kebbi: 1 / 0 / 0
Kogi: 2 / 1 / 1
Nasarawa: 26 / 6 / 2
Ogun: 8 / 1 / 0
Ondo: 13 / 6 / 2
Plateau: 5 / 4 / 3
Rivers: 6 / 1 / 0
Taraba: 37 / 12 / 9
Yobe: 1 / 0 / 0

Total: 255 / 58 / 46

--
communicated by:
Olutayo Olajide Babalobi
Lecturer and Consultant Epizootiologist
(One Health, Participatory Epizootiology and Veterinary ICT Research Group)
Department of Veterinary Public Health and Preventive Medicine
Faculty of Veterinary Medicine
University of Ibadan
Ibadan
Nigeria

[Dr Olutayo Olajide Babalobi is thanked for sending in this report.

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 posts, 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

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

See Also
Lassa fever - West Africa (17): Nigeria 20170513.5033800
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
.................................................ty/ao/sh