LASSA FEVER - WEST AFRICA (34): NIGERIA

Posted on 17TH JUN 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 10 Jun 2018
Source: Nigeria Centre for Disease Control [edited]
https://reliefweb.int/sites/reliefweb.int/files/resources/An%20update%20...

Highlights
- In the reporting Week 23 (4-10 Jun 2018) 5 new confirmed cases were reported from Edo (4) and Ondo (1) states with one death recorded in Edo state.
- From 1 Jan - 10 Jun 2018, a total of 1999 suspected cases have been reported from 21 states. Of these, 437 were confirmed positive, 10 are probable, 1552 negative (not a case).
- Since the onset of the 2018 outbreak, there have been 109 deaths in confirmed cases and 10 in probable cases. Case fatality rate in confirmed cases is 24.9 percent - Table 1.
- 21 states have recorded at least one confirmed case across 71 Local Government Areas (Edo, Ondo, Bauchi, Nasarawa, Ebonyi, Anambra, Benue, Kogi, Imo, Plateau, Lagos, Taraba, Delta, Osun, Rivers, FCT, Gombe, Ekiti, Kaduna, Abia and Adamawa); 19 states have exited the active phase of the outbreak while 2, Edo and Ondo states, remain active - Table 1/Figure 1.
- In reporting week 23, no new healthcare worker was infected; 38 health care workers have been affected since the onset of the outbreak in 7 states: Ebonyi (16), Edo (13), Ondo (4), Kogi (2), Nasarawa (1), Taraba (1) and Abia (1) with 9 deaths in Ebonyi (6), Kogi (1), Abia (1) and Ondo (1).
- The age-group 21-40 years is predominantly affected (median age: 32 years) - Figure 6.
- The male to female ratio for confirmed cases is 1.6:1.
- 81 percent of all confirmed cases are from Edo (42 percent), Ondo (24 percent) and Ebonyi (15 percent) states.
- 4 patients are currently being managed at 2 treatment centres - 3 at Irrua Specialist Teaching Hospital (ISTH) and one at the Federal Medical Centre Owo treatment Centre - Table 1.
- A total of 5508 contacts have been identified from 21 states. Of these, 170 (3.1 percent) are currently being followed up, 5328 (96.7 percent) have completed 21 days follow, up while 10 (0.2 percent) were lost to follow up. 84 symptomatic contacts have been identified, of which 29 (35 percent) have tested positive from 5 states (Edo-13, Ondo-8, Ebonyi-3, Kogi-3, Bauchi-1, and Adamawa-1) - Table 1.
- National intensive clinical workshop on diagnosis, management and control of Lassa fever in collaboration with ISTH North-east/North-west zones scheduled for 12-14 Jul 2018 in Kano state.
- The Lassa fever 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 10 Jun 2018.
Figure 2 [map]: Distribution of suspected and confirmed Lassa fever cases in Nigeria by LGA.
Figure 3 [graph]: Epicurve of Lassa fever confirmed (437) and probable (10) cases in Nigeria week 1-23, 2018.
Figure 4 [graph]: Weekly trends of Lassa fever confirmed cases in Nigeria, 2016-2018.
Figure 5 [graph]: Confirmed Lassa fever cases in Nigeria with state specific case fatality rates (CFR) as at 10 Jun 2018.
Figure 6 [graph]: Age-sex distribution of confirmed Lassa fever cases in Nigeria as at 10 Jun 2018.
Figure 7 [graph]: Epicurve of confirmed cases of Lassa fever in Edo State week 1-23, 2018.
Figure 8 [graph]: Distribution of Lassa fever confirmed cases in Edo State by LGA as at 10 Jun 2018.
Figure 9 [graph]: Epicurve of Lassa fever confirmed cases in Ondo State week 1- 23, 2018.
Figure 10 [graph]: Epicurve of Lassa fever confirmed cases in Ebonyi State week 1- 23, 2018.

--
Communicated by:
ProMED-mail from HealthMap Alerts

[With 5 new cases, the incidence of Lassa fever cases may be slowing and perhaps ending for this transmission season, although the Lassa fever virus transmission season usually lasts into June, so a few more cases might occur. The graphs of the epidemic curves continue to indicate that the peak number of cases nationally has passed. This outbreak has been wide-spread, occurring in 21 states and 71 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, _Mastomys natalensis_ can be seen at https://www.inaturalist.org/taxa/45326-Mastomys-natalensis and _M. erythroleucus_ and _Hylomycus pamfi_ at: 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 (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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