LASSA FEVER - WEST AFRICA (21): NIGERIA

Posted on 18TH JUN 2017
tagged Lassa Fever, West Africa; Nigeria

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Date: Fri 9 Jun 2017
Source: Nigeria Centre for Disease Control [NCDC] Weekly Epidemiological Report 7(21) [edited]
http://www.ncdc.gov.ng/reports/weekly

1. Lassa fever
Please note that the data reflects the routine reports i.e. all suspected cases including the laboratory positive and negative cases
1.1. One suspected case of Lassa fever was reported from Abeokuta South LGAs (Ogun States) in week 21, 2017 compared with 24 suspected cases with one Lab. Confirmed and one death (CFR, 4.2 percent) from Esan Central LGA (Edo State) at the same period in 2016.
1.2. Laboratory results of the one suspected case was negative (Ogun - 1).
1.3. Between weeks 1 and 21 (2017), 263 suspected Lassa fever cases with 59 laboratory confirmed cases and 48 deaths (CFR, 18.25 percent) from 54 LGAs (20 States) were reported compared with 716 suspected cases with 71 laboratory confirmed cases and 87 deaths (CFR, 12.15 percent) from 125 LGAs (27 States) during the same period in 2016 (Figure 1).
1.4. Between weeks 1 and 52 2016, 921 suspected Lassa fever cases with 109 laboratory confirmed cases and 119 deaths (CFR, 12.92 percent) from 144 LGAs (28 States and FCT) were reported compared with 430 suspected cases with 25 laboratory confirmed cases and 40 deaths (CFR, 9.30 percent) from 37 LGAs (14 States and FCT) during the same period in 2015 (Figure 2).
1.5. Investigation and active case search ongoing in affected States with coordination of response activities by the NCDC with support from partners.
1.5.1. National Lassa Fever Working Group meeting and weekly National Surveillance and Outbreak Response meeting on-going 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 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. NCDC team sent to Edo State to support Lassa fever data harmonization and Updating of VHF case-based management database
1.5.8. Confirmed cases are being treated at identified treatment/isolation centres across the States with Ribavirin and necessary supportive management also instituted
1.5.9. Onsite support was earlier provided to Ogun, Nasarawa, Taraba, Ondo and Borno States by the NCDC and partners
1.5.10. Offsite support provided by NCDC/partners in in all affected States
1.5.11. States are enjoined to intensify surveillance

Figure 1: Map of Nigeria showing areas affected by Lassa fever, week 1- 21, 2016 and 2017
Figure 2: Map of Nigeria showing areas affected by Lassa fever, week 1 - 53, 2015 and week 1 - 52, 2016

Table of cases by state, cumulative data weeks 1-20 [1 Jan-19 May 2017]:
State: Cases / Lab Confirmed / Deaths
Adamawa: 6 / 0 / 2
Bauchi: 9 / 3 / 3
Cross River: 6 / 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 / 1
Kogi: 2 / 1 / 1
Nasarawa: 28 / 6 / 2
Ogun: 9 / 1 / 0
Ondo: 13 / 6 / 2
Plateau: 7 / 5 / 5
Rivers: 6 / 1 / 0
Taraba: 37 / 12 / 9
Yobe: 1 / 0 / 1
262 59 48
Total: 263 / 59 / 48

--
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

[There is just one additional case since the last epidemiological report of the previous week. The numbers of cases of Lassa fever have been continuing to slowly increase in Nigeria however. As noted in earlier comments, Lassa fever remains a problem in Nigeria because the virus is endemic there. Virus transmission to humans occurs 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 protective equipment is not employed and barrier nursing practices are not adequate to protect staff from blood and secretions of infected patients.

Effective treatment of Lassa virus has been a challenge. There may be an effective vaccine on the horizon. A press release sent to us by Leann Bailey stated that utilizing antibodies from Zalgen and Tulane University (Tulane) coupled to the Lassa virus GPC, researchers at The Scripps Research Institute (TSRI) and other VHFC and VIC affiliated organizations successfully characterized the 1st high-resolution image of an arenavirus glycoprotein in its native trimer structure, expanding the capability for developing significantly more effective medical countermeasures. Several Zalgen/Tulane antibodies have demonstrated effectiveness as immunotherapeutics. Zalgen's 1st immunotherapeutic candidate, Arevirumab-3 demonstrated 100 percent efficacy in treating infected animals using 2 relevant model systems, and will advance to pre-clinical development, with projected Phase I studied within 3 years. The newly solved Lassa virus GPC trimer will also enable the design of better vaccines to elicit successful antibodies in recipients.

Images of _Mastomys_ mice, the rodent reservoir of Lass fever virus, 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 (20): Nigeria 20170607.5088880
Lassa fever - West Africa (19): Nigeria 20170604.5082193
Lassa fever - West Africa (18): Nigeria 20170530.5070103
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
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