LASSA FEVER - WEST AFRICA (44): NIGERIA

Posted on 05TH NOV 2018
tagged Lassa Fever, West Africa; Nigeria

A ProMED-mail post
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International Society for Infectious Diseases
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Date: Sun 28 Oct 2018
Source: Nigeria Center for Disease Control Situation Report [edited]
https://ncdc.gov.ng/diseases/sitreps/?cat=5&name=An%20update%20of%20Lass...

Highlights

- In the reporting week 43 (22-28 Oct 2018), 9 new confirmed cases were reported from the states of Ondo (4 [cases]), Edo (4), and Ebonyi (1), with 2 new deaths in Edo (1) and Ondo (1) and a probable case from Ebonyi.
- From 1 Jan-28 Oct 2018, a total of 2834 suspected cases have been reported from 22 states. Of these, 548 were confirmed positive, 17 are probable, and 2264 are negative (not a case).
- Since the onset of the 2018 outbreak, there have been 141 deaths in confirmed cases and 17 in probable cases. The case fatality rate in confirmed cases is 25.7 percent (table 1; see URL above).
- 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). Sixteen states have exited the active phase of the outbreak, while 6 (Edo, Ondo, Ebonyi, Kogi, Delta, and Imo) remain active (table 1/figure 1; see URL above).
- In the reporting week 43, no new healthcare worker was affected; 41 healthcare workers have been affected since the onset of the outbreak in 7 states -- Ebonyi (16), Edo (15), Ondo (5), Kogi (2), Nasarawa (1), Taraba (1), and Abia (1) -- with 10 deaths in Ebonyi (5), Kogi (1), Abia (1), Ondo (2), and Edo (1).
- 82 percent of all confirmed cases are from Edo (46 percent), Ondo (23 percent), and Ebonyi (13 percent) states.
- Currently, 12 patients are being managed at Irrua Specialist Teaching Hospital (ISTH) treatment centre (8), Federal Medical Centre (FMC) Owo (3), and Federal Teaching Hospital Abakiliki (1) (table 1; see URL above).
- A total of 8454 contacts have been identified from 22 states. Of these, 389 (4.6 percent) are currently being followed up with, 7946 (94 percent) have completed 21 days follow-up, while 15 (0.2 percent) were lost to follow-up. 109 (1.3 percent) symptomatic contacts have been identified, of which 36 (0.5 percent) have tested positive from 5 states: Edo (20), Ondo (8), Ebonyi (3), Kogi (3), Bauchi (1), and Adamawa (1) (table 1; see URL above).
- National RRT team (NCDC staff and NFELTP residents) deployed Ondo state to support response.
- Lassa fever international conference registration, abstract submission, and travel scholarship are now open to the public on the conference website, , with the date for abstract submission extended to Wed 14 Nov 2018.
- Lassa fever national multi-partner, multi-agency Technical Working Group (TWG) continues to coordinate response activities at all levels.

Figure1 [map]: Distribution of confirmed Lassa fever cases in Nigeria as at 28 Oct 2018
Figure 2 [map]: Distribution of suspected and confirmed Lassa fever cases in Nigeria by LGA
Figure 3 [graph]: Epicurve of Lassa fever confirmed (548) and probable (17) cases in Nigeria week 1-43, 2018
Figure 4 [graph]: Weekly trends of Lassa fever confirmed cases in Nigeria, 2016-2018, week 43
Figure 5 [graph]: Confirmed Lassa fever cases in Nigeria with state-specific case fatality rates (CFR) as at 28 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 9 new confirmed cases and 2 new deaths 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
Lassa fever - West Africa (43): Nigeria (ON) 20181030.6119637
Lassa fever - West Africa (42): Nigeria 20181020.6101683
Lassa fever - West Africa (41): Nigeria 20180815.5967485
Lassa fever - West Africa (40): Nigeria (EN) 20180809.5955565
Lassa fever - West Africa (39): Nigeria (ED) 20180727.5931747
Lassa fever - West Africa (38): Nigeria 20180717.5909251
Lassa fever - West Africa (36): Nigeria (ON) 20180701.5884285
Lassa fever - West Africa (34): Nigeria 20180617.5859861
Lassa fever - West Africa (31): Nigeria 20180605.5840563
Lassa fever - West Africa (29): Nigeria 20180530.5829096
Lassa fever - West Africa (26): Nigeria 20180509.5790856
Lassa fever - West Africa (25): WHO Nigeria 20180422.5761965
Lassa fever - West Africa (23): Liberia, WHO 20180417.5753003
Lassa fever - West Africa (22): Nigeria 20180410.5738206
Lassa fever - West Africa (21): Nigeria 20180406.5727850
Lassa fever - West Africa (20): Nigeria 20180327.5714291
Lassa fever - West Africa (19): Nigeria 20180315.5687321
Lassa fever - West Africa (18): Nigeria (BA) 20180313.5683816
Lassa fever - West Africa (16): Nigeria 20180306.5670231
Lassa fever - West Africa (14): Nigeria 20180228.5655382
Lassa fever - West Africa (13): Nigeria 20180222.5645501
Lassa fever - West Africa (12): Nigeria 20180221.5641157
Lassa fever - West Africa (11): Nigeria, WHO 20180215.5629350
Lassa fever - West Africa (10): Nigeria 20180212.5622070
Lassa fever - West Africa (07): Nigeria 20180206.5608967
Lassa fever - West Africa (06): Nigeria (DE, ON) 20180201.5600192
Lassa fever - West Africa (05): Nigeria 20180131.5597457
Lassa fever - West Africa (04): Nigeria 20180125.5585380
Lassa fever - West Africa (03): Benin (AK) ex Nigeria, WHO 20180124.5581805
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