Outbreaks and Emergencies Bulletin, Week 37: 9 - 15 September 2019
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Lassa fever Liberia
36 Cases
11 Deaths
41% CFR
EVENT DESCRIPTION
Liberia continues to report sporadic cases of Lassa fever. On 8
September 2019, WHO was notified of two new confirmed cases
reported from Bong and Grand Bassa Counties in the central part
of Liberia. The first case is a 30-year-old male laboratory technician
who was a resident of Suakoko District, Bong County. He reportedly
presented to a local hospital on 6 August 2019 with fever (≈38.9?C),
vomiting, general weakness, abdominal pain and anorexia and was
treated as an out patient for malaria and typhoid fever. Lack of response
to anti-malarial and antibiotic treatment and subsequent worsening of
his condition led to admission to a hospital on 19 August 2019, where
blood samples were collected due to suspicion of viral haemorrhagic
fever. Test results released by the National Public Health Reference
Laboratory of Liberia (NPHRL) on 22 August 2019 confirmed the
case as positive for Lassa virus infection by reverse-transcriptase
polymerase chain reaction (RT-PCR). He died on 21 August 2019 while
undergoing clinical care and a safe and dignified burial was conducted.
A total of 30 contacts, including 18 healthcare workers, were identified
and are being monitored.
The second case is an 11-year-old female resident of District #3A&B,
Grand Bassa County who presented at a local hospital on 20 August
2019 with signs and symptoms of fever (>38.5?C), general weakness,
anorexia, swollen neck, vomiting, cough, and pain in the throat. She
was unresponsive to anti-malarial treatment administered as an out
patient, and the attending clinicians suspected a viral haemorrhagic
fever. She was admitted at the Lassa fever treatment unit and a sample
taken on 31 August 2019. Test results released by the NPHRL on 2
September 2019 confirmed the case-patient as positive for Lassa virus
infection by RT-PCR. In spite of clinical care, the case-patient died
on 4 September 2019 and safe burial was subsequently conducted
under the supervision of the district health team. A total of 16 contacts
including five healthcare workers were listed and are being followed.
From 1 January to 8 September 2019, a total of 106 suspected cases
including 22 deaths have been reported across the country. Of 97
suspected cases sampled, 27 tested positive by RT-PCR at the NPHRL
while 70 were discarded due to negative test results. Confirmed cases
have been reported from four counties, namely; Bong (11), Nimba
(9), Grand Bassa (6), and Grand Kru (1). The case fatality ratio among
confirmed cases is 41% (n=11) and males are the most affected
accounting for 52% (n=14) of the confirmed cases. In total, 122
contacts have been listed and are currently under follow-up in the Bong
and Grand Bassa Counties.
PUBLIC HEALTH ACTIONS
The response to Lassa fever outbreaks continues to be
coordinated at sub-national level under the leadership of the
county health teams with technical and logistical support from
the National Public Health Institute of Liberia (NPHIL), Liberia?s
Ministry of Health, WHO Liberia Country Office, the US Centre for
Disease Control and Prevention Liberia Office, and a host of other
partners. The National Epidemic Preparedness and Response
Committee (NEPRC) involving NPHIL, WHO, and other technical
institutions continue to monitor the situation across the country
and provide support to response efforts.
National-level multidisciplinary teams have been dispatched to
enhance further investigation and strengthen response actions at
the county level. Case investigation, contact tracing, and active
case search are ongoing in the affected counties. Screening
tools have been distributed to health facilities to aid in the early
identification of cases.
The National Public Health Reference Laboratory of Liberia
(NPHRL) continues to conduct tests for viral haemorrhagic fevers
including Lassa fever. Couriers are stationed at designated points
across the country for transportation of specimens to the NPHRL
for testing.
There is currently one case-patient at the Lassa fever treatment centre in Bong
County undergoing clinical care. A refresher of health workers on clinical
management of Lassa fever cases is being planned.
Exposure risk assessment for healthcare workers is being routinely conducted as
part of investigation missions. These missions are also used to conduct infection
prevention and control assessments as well as mentoring of staff in affected and
circumscribed facilities.
Risk communication and community engagement activities targeting affected
households and communities are ongoing through town hall meetings, including
messages on risk factors for exposure to the disease, as well as preventive
strategies, including safe handling and storage of food items and environmental
cleanliness.
SITUATION INTERPRETATION
Lassa fever is endemic in parts of Liberia and sporadic cases are reported year-round
with a peak in the dry season, which begins in November. The traditional Lassa fever
belt in the country appears to be expanding with confirmed autochthonous cases being
reported from the south eastern region not previously known to be endemic for the
disease. Furthermore, response efforts seem to be challenged by late detection of cases
leading to high case fatality ratio, stock out of ribavirin used to treat Lassa fever, and
sub-optimal vector control activities. As the country approaches the beginning of the
dry season, it is anticipated that the number of cases will increase. Government and
partners need to step up efforts aimed at strengthening early detection and treatment
of cases, improving infection control and prevention practices in healthcare facilities, as
well as engaging communities and enhancing vector control activities.
https://www.afro.who.int/node/11740
https://apps.who.int/iris/bitstream/handle/10665/327408/OEW37-0915092019.pdf
