LASSA FEVER - WEST AFRICA (46): NIGERIA

Posted on 25TH NOV 2018
tagged Lassa Fever, West Africa; Nigeria

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Date: Sun 18 Nov 2018
Source: Nigeria Center for Disease Control (NCDC) [edited]
https://ncdc.gov.ng/diseases/sitreps/?cat=5&name=An%20update%20of%20Lass...

Highlights
- In the reporting week 46 (12-18 Nov 2018), 3 new confirmed cases were reported from Edo (1) and Ondo (2) states with one new death.
- From 1 Jan-18 Nov 2018, a total of 3086 suspected cases have been reported from 22 states. Of these, 562 were confirmed positive, 17 probable, 2507 negative (not a case).
- Since the onset of the 2018 outbreak, there have been 144 deaths in confirmed cases and 17 in probable cases. Case fatality rate (CFR) in confirmed cases is 25.6 percent.
- 22 states have recorded at least one confirmed case across 90 local government areas (Edo, Ondo, Bauchi, Nasarawa, Ebonyi, Anambra, Benue, Kogi, Imo, Plateau, Lagos, Taraba, Delta, Osun, Rivers, FCT, Gombe, Ekiti, Kaduna, Abia, Adamawa, and Enugu). Three states -- Edo, Ondo, and Ebonyi -- are in the active phase of the outbreak (Figure 1).
- In the reporting week 46, no new healthcare worker was affected; 43 healthcare workers have been affected in 7 states since the onset of the outbreak -- Ebonyi (16), Edo (15), Ondo (7), Kogi (2), Nasarawa (1), Taraba (1), and Abia (1) -- with 10 deaths from Ebonyi (5), Kogi (1), Abia (1), Ondo (2), and Edo (1).
- 83 percent of all confirmed cases are from Edo (46 percent), Ondo (24 percent), and Ebonyi (13 percent) states.
- 3 patients are currently being managed at Irrua Specialist Teaching Hospital (ISTH) treatment Centre (1) and Federal Medical Centre (FMC) Owo (2).
- A total of 9045 contacts have been identified from 22 states. Of these, 370 (4 percent) are currently being followed-up with, 8545 (94 percent) have completed 21 days of follow-up, while 15 (0.2 percent) were lost to follow-up. 115 (1.3 percent) symptomatic contacts have been identified, of which 36 (0.5 percent) have tested positive from 5 states (Edo (20), Odo (8), Ebonyi (3), Kogi (3), Bauchi (1), and Adamawa (1).
- Workshop on review and update of Lassa fever case management guideline.
- Lassa fever international conference scheduled for 16-17 Jan 2019; registration ongoing at .
- Lassa fever national multi-partner, multi-agency Technical Working Group (TWG) continues to coordinate response activities at all levels.

Figure 1 [map]: Distribution of confirmed Lassa fever cases in Nigeria as at 18 Nov 2018.
Figure 2 [map]: Distribution of confirmed Lassa fever cases in Nigeria by LGA as at 18 Nov 2018.
Figure 3 [graph]: Epicurve of Lassa fever confirmed (564) and probable (17) cases in Nigeria week 1-46, 2018.
Figure 4 [graph]: Weekly trends of Lassa fever confirmed cases in Nigeria, 2016-2018, week 46.
Figure 5 [graph]: Confirmed Lassa fever cases in Nigeria with state-specific case fatality rates (CFRs) as at 18 Oct 2018.

--
Communicated by:
ProMED-mail from HealthMap Alerts

[Although the graphs in the above report clearly show that the Lassa fever virus transmission peak has passed, the 3 new confirmed cases and one new death indicate that Lassa fever virus transmission continues, and a few more cases might occur. Fortunately, no healthcare workers were infected during this reporting period. This outbreak has been widespread, occurring in 22 states and 90 local government areas. It would be interesting to know whether the prevalence of Lassa fever virus has been increasing in populations of rodent hosts in this area.

Images of the rodent reservoirs of Lassa fever virus can be seen as follows:
For _Mastomys natalensis_, see https://www.inaturalist.org/taxa/45326-Mastomys-natalensis.
For _M. erythroleucus_ and _Hylomycus pamfi_, see http://punchng.com/nigerias-large-rat-population-threatens-lassa-fever-war/.

The maps and graphs in the report above are interesting and provide a good picture of how the outbreak has progressed over time. They can be accessed at the source URL above.

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

See Also
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