LASSA FEVER - WEST AFRICA (19): NIGERIA
Posted on 04TH JUN 2017
tagged Lassa Fever, West Africa; Nigeria
Date: Fri 26 May 2017
Source: Nigeria Centre for Disease Control [NCDC] Weekly Epidemiological Report 7 (19) [edited]
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. Two suspected cases of Lassa fever were reported from two LGAs ([local government areas] 2 states) in week 19, 2017 compared with zero during the same period in 2016.
1.2. Laboratory results of the 2 suspected cases were negative (Cross River - 1 and Nassarawa - 1).
1.3. Between weeks one and 19 (2017), 258 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 per cent) from 122 LGAs (27 states) during the same period in 2016 (figure 1).
1.4. Between weeks 1 and 52 of 2016, 921 suspected Lassa fever cases with 109 laboratory confirmed cases and 119 deaths (CFR 13 per cent) from 144 LGAs (28 states and the Federal Capital Territory [FCT]) were reported compared with 430 suspected cases with 25 laboratory confirmed cases and 40 deaths (CFR 9 per cent) from 37 LGAs (14 states and the 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 NCDC with support from partners.
1.5.1. National Lassa Fever Working Group meeting and weekly National Surveillance and Outbreak Response meeting ongoing at NCDC to keep abreast of the current Lassa fever situation in the country.
1.5.2. Response materials for viral haemorrhagic fevers [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. 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 1-19, 2016 and 2017
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 1-19:
State: Cases / Lab Confirmed / Deaths
Adamawa: 6 / 0 / 2
Bauchi: 9 / 3 / 3
Cross River: 5 / 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: 27 / 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 / 1
Total: 258 / 58 / 46
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
[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]
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