WEEKLY BULLETIN ON OUTBREAKS
AND OTHER EMERGENCIES
Week 34: 16 - 22 August 2021
Data as reported by: 17:00; 22 August 2021
...
Lassa Fever Nigeria
354 Cases
73 Deaths
21% CFR
EVENT DESCRIPTION
Lassa fever (LF) is endemic to several West African countries
including Nigeria, Liberia and Sierra Leone. LF is associated with
significant morbidity and mortality. According to the Centers
for Disease Control, the annual incidence of LF in this region is
estimated as 100 000 to 300 000 cases with about 5 000 deaths and
58 million people at risk.
The ongoing LF outbreak in Nigeria that started in 2017 has seen a
decreasing trend, with fewer cases reported since week 11 2021.
In week 32 (week ending 15 August 2021), the number of new
confirmed LF cases (4 cases) was similar to that reported in the
previous week (week 31). These new cases came from three states:
Ondo (2), Edo (1), and Enugu (1). Two new deaths from Ondo were
reported in the same period. There were four case-patients admitted
to treatment centres during the reporting week, and 204 contacts
under follow up. No new healthcare worker infection was recorded
in week 32.
The number of suspected cases has decreased compared to that
reported for the same period in 2020. From weeks 1-32 of 2021,
a cumulative total of 2 742 suspected Lassa fever cases has been
reported, of which 354 (13.0%) were laboratory confirmed. The
confirmed cases occurred across 14 states that recorded at least
one confirmed case. Edo State recorded the highest number of
confirmed cases at 158 (45%), followed by Ondo State with 117
(33%); the two states accounts for 78% of all confirmed cases. A
total of six health workers were infected with the disease in 2021.
Cumulatively, from week 1 to week 32 2021, 73 deaths have been
reported with a case fatality ratio (CFR) of 21% which is lower than
the CFR for the same period in 2020 (21%).
The predominant age-group affected is 21-30 years (range: <1 to 70
years, median age 29 years). The male to female ratio for confirmed
cases in 1:0.8.
PUBLIC HEALTH ACTIONS
National Lassa fever multi-partner, multi-sectoral Technical
Working Group (TWG) continues to coordinate the response
activities at all levels
National Rapid Response Team have been deployed from
the Nigerian Centre for Disease Control (NCDC) to support
response activities in Kaduna, Bauchi and Taraba states.
Multi-sectoral Public Health Emergency Operation Centres
(PHEOC) were activated in affected States
Vector control measures in Edo and Ondo States have been
implemented periodically.
Case management and safe burial practices guidelines were
reviewed and disseminated
Mortality review of lassa fever deaths and an in-depth
investigation of healthcare worker infections were conducted.
Distributed response commodities; personal protective
equipment, Ribavirin (injection and tablets), body-bags,
thermometers, hypochlorite hand sanitizers to states and
treatment centres.
Surveillance activities have been enhanced in affected states,
with contact tracing and active case finding underway.
Implementation of targeted risk communication activities in
most affected States, with a national Lassa fever awareness
and prevention campaign planned.
The Lassa Fever Environmental response campaign has been
implemented in high burden states by the Federal Ministry of
Environment.
Implementation of Nigeria Lassa fever epidemiological study
supported by Coalition for Epidemic Preparedness Innovations
is ongoing.
SITUATION INTERPRETATION
While the Lassa fever outbreak in Nigeria appears to be
declining, there is little room for complacency as the vector
is endemic to the region and environmental conditions are
favorable to disease spread. Active case finding and contact
tracing and follow-up need to continue to prevent resurgence
of the disease in this endemic region. Furthermore, the local
and national authorities need to remain vigilant on this event in
the wake of the shifting priorities to other health emergencies,
particularly COVID-19 pandemic.
PROPOSED ACTIONS
Authorities in Nigeria need to continue to employ the highest
levels of surveillance and response as the Lassa fever outbreak
in the country starts to show signs of decline. Affected states
need to be supported to develop and implement Lassa fever
response sustainability plan Focus must not be diverted from
this ongoing outbreak by the requirements of response to the
COVID-19 outbreak.
...
https://apps.who.int/iris/bitstream/handle/10665/344445/OEW34-1622082021.pdf
