WEEKLY BULLETIN ON OUTBREAKS
AND OTHER EMERGENCIES
Week 6: 30 January to 5 February 2023
Data as reported by: 17:00; 5 February 2023
...
Lassa Fever Nigeria
244 cases
37 Deaths
15.2% CFR
EVENT DESCRIPTION
From week 1 through week 3, 2023, a total of 244 new confirmed
cases of Lassa fever, including 37 deaths with a case fatality ratio
of 15.2%, have been reported in 16 states. The highest number
of cases was reported in Ondo (90) and Edo (89) states, followed
by Bauchi (13), Taraba (10), Benue (9), Ebonyi (9), Nasarawa (7),
Plateau (5), Kogi (4), Anambra (2), Delta (1), Oyo (1), Adamawa
(1), Enugu (1), and Imo (1) states; one case was reported from
the Federal Capital Territory (FCT) (1).
About 79% of all confirmed Lassa fever cases were reported
from three states (Ondo, Edo, and Bauchi), while 21% were
reported from 13 states. Of the 79% of confirmed cases, Ondo
reported 37%, Edo 36%, and Bauchi 5%. In total for 2023, 16
States have recorded at least one confirmed case across 50 Local
Government Areas.
Of the reported cases, the predominant age group affected is
21-30 years (range: 1 to 79 years) and the Median age is 30
years. The male-to-female ratio for confirmed cases is 1:0.9.
Five confirmed cases and one death were reported among health
workers.
In week 3 alone, the number of new confirmed cases increased
from 77 in week 2, 2023 to 137 cases and the number of deaths
from six in week 2 to 18 in week 3. These cases were reported
from Ondo, Edo, Taraba, Benue, Nasarawa, Bauchi, Ebonyi,
Plateau, Kogi, Anambra, Delta, FCT, Adamawa, and Enugu states.
A total of two confirmed cases among health Care workers were
reported in the reporting week.
Compared to the previous year 2022, from week 1 to week 3,
the number of confirmed cases has increased from 170 cases
in 2022 to 244 cases in 2023. A total of 12 states and 37 Local
Government Areas (LGAs) were affected in 2022 against 16 states
and 50 LGAs in 2023. However, the case fatality ratio was higher
in 2022 (18.8%, 32/170) compared to 2023 (15.1%, 37/244) for
the same period.
Regarding suspected cases reported, a total of 939 were reported
for the three epidemiological weeks of 2023 among which 244
were confirmed (30.0%),the number of suspected cases reported
increased compared to that reported for the same period in 2021
(354) and 2022 (759).
A cumulative number of 700 contacts were listed since the
beginning of this year and 518 are under follow up, 183
completed follow up, four contacts developed symptoms and no
contact tested positive for Lassa fever. A total of 226 cases were
managed at the treatment centre.
PUBLIC HEALTH ACTIONS
At national level, the Nigeria Centre for Disease Control
and Prevention (NCDC) activated the National Multisectoral
Emergency Operations Center for Lassa Fever at Level 2 to
coordinate and strengthen the ongoing response activities in
the country, following a risk assessment carried out on 20
January 2023.
A workshop to validate the five-year Strategic plan for Lassa
fever was organized.
The dissemination of the reviewed case management and
safe burial practices guidelines has been done.
The mortality review of Lassa fever deaths as well as indepth
investigation of healthcare worker infections were performed.
The preparation of the External Quality Assurance panel for
all testing laboratories is ongoing.
The distribution of response commodities to the affected
states and treatment centers was conducted, these included:
personal protective equipment (PPEs), Ribavirin (injection
and tablets), body-bags, thermometers, hypochlorite hand
sanitizers and IEC materials
The implementation of Nigeria Lassa fever epidemiological
Study is ongoing.
The Multi-sectoral Public Health Emergency Operation
Centers (PHEOC) were activated in affected states.
SITUATION INTERPRETATION
Lassa fever is endemic in Nigeria with seasonal outbreaks reported
and the number of cases typically increases between December
and March, which coincides with the dry season in the country.
For the past five- year’s period, from week 1 through week 3 of
each year, except in 2021, the trend in number of suspected and
confirmed cases has been increasing as well as the number of the
affected Local Government Areas and States, however the case
fatality ratio is decreasing since 2021. This may be considered
as the positive impact of the strengthened surveillance and case
management response activities. Lassa fever is one of diseases
linked to poor environmental health conditions.
https://apps.who.int/iris/bitstream...EW06-300105022023.pdf?sequence=10&isAllowed=y
