WEEKLY BULLETIN ON OUTBREAKS
AND OTHER EMERGENCIES
Week 46: 11 - 17 November 2019
Data as reported by: 17:00; 17 November 2019
Circulating vaccine-derived
poliovirus type 2 C?te d’Ivoire
EVENT DESCRIPTION
On 28 October 2019, WHO was notified of an environmental
sample from Cote d’Ivoire that tested positive for circulating
vaccine-derived poliovirus type 2 (cVDPV2). The virus was
isolated from a wastewater sample collected as part of
environmental surveillance on 24 September 2019, at Jacob
Site, Boribana district, Abidjan. Tests conducted at the National
Institute of Communicable Diseases (NICD) Laboratory in South
Africa detected the virus, which has undergone 17 nucleotide
changes and is linked to a virus detected in Magaria district,
Niger in 2018 thus indicating circulation. The virus belongs to
the Jigawa emergence group which has also been detected in
Cameroon, Chad, Niger, Benin, Ghana, and Togo.
The last wild poliovirus was reported in 2011 and this is the first
report of a positive cVDPV2 environmental sample from Cote
d’Ivoire. Inactivated polio vaccine (IPV) immunization coverage
across the country was 67% in 2018. The affected area had not
previously participated in the monovalent oral poliovirus type 2
(mOPV2) campaign.
PUBLIC HEALTH ACTIONS
The National Management Committee for Epidemic Response
with technical advice from WHO and partners convened to
review the situation and adapt strategies in response to the
event.
An investigation team has been deployed to the affected area
and a high-level joint field mission to assess the situation in
the area took place on 11 November 2019.
Two rounds of reactive immunization campaigns using
mOPV2 have been planned. However, implementation of the
plan has been delayed in favour of strengthening surveillance
for Acute Flaccid Paralysis (AFP) as well as environmental
monitoring.
Epidemiological surveillance for poliovirus is being
strengthened through intensification of active case search
for AFP cases, refresher training of health workers on case
definitions, training of surveillance focal points on the use
of open data kit (ODK) platforms to enhance early reporting
of suspected cases, and expansion of AFP surveillance
reporting sites to 12 additional private health facilities. A plan
is also being developed for visiting priority sites.
Routine immunization outreaches at market places and
other settings continue and community-based surveillance
activities have been integrated with these activities to identify
potential AFP cases.
SITUATION INTERPRETATION
Circulating vaccine-derived virus type 2 continues to be reported across the African
region with C?te d’Ivoire being among the latest countries to report a positive
environmental sample. The country introduced IPV in 2015 but immunization
coverage has been low with limited stock of the vaccine for a protracted period
from 2017 to 2018. According to the WHO-UNICEF routine immunization
coverage estimates, IPV coverage was estimated to be 67% in 2018. The quality
of supplementary immunization activities has also been sub-optimal in some of the
districts in the city of Abidjan. WHO continues to emphasize the need to strengthen
surveillance for AFP cases in order to rapidly detect any new virus importation and
to facilitate a rapid response as well as maintain high levels of routine immunization
coverage across the country to minimize the consequences of any new introduction
of the virus.
https://apps.who.int/iris/bitstream/item/334140/OEW46-18112019.pdf
https://www.afro.who.int/publications/outbreaks-and-emergencies-bulletin-week-46-11-17-november-2019
