An outbreak of wild poliovirus in the Republic of Congo, 2010-2011.
BACKGROUND
The Republic of Congo has had no cases of wild poliovirus type 1 (WPV1) since 2000. In October 2010, a neurologist noted an abnormal number of cases of acute flaccid paralysis (AFP) among adults, which were later confirmed to be caused by WPV1.


METHODS
Those presenting with AFP underwent clinical history, physical examination, and clinical specimen collection to determine if they had polio. AFP cases were classified as laboratory-confirmed, clinical, or nonpolio AFP. Epidemiologic features of the outbreak were analyzed.


RESULTS
From 19 September 2010 to 22 January 2011, 445 cases of WPV1 were reported in the Republic of Congo; 390 cases were from Pointe Noire. Overall, 331 cases were among adults; 378 cases were clinically confirmed, and 64 cases were laboratory confirmed. The case-fatality ratio (CFR) was 43%. Epidemiologic characteristics differed among polio cases reported in Pointe Noire and cases reported in the rest of the Republic of Congo, including age distribution and CFR. The outbreak stopped after multiple vaccination rounds with oral poliovirus vaccine, which targeted the entire population.


CONCLUSIONS
This outbreak underscores the need to maintain high vaccination coverage to prevent outbreaks, the need to maintain timely high-quality surveillance to rapidly identify and respond to any potential cases before an outbreak escalates, and the need to perform ongoing risk assessments of immunity gaps in polio-free countries.
Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA. hgo9@cdc.gov
Minal K
MK
Patel
Mandy Kader
MK
Konde
Boris Hermann
BH
Didi-Ngossaki
Edouard
E
Ndinga
Riziki
R
Yogolelo
Mbaye
M
Salla
Keith
K
Shaba
Johannes
J
Everts
Gregory L
GL
Armstrong
Danni
D
Daniels
Cara
C
Burns
Steve
S
Wassilak
Mark
M
Pallansch
Katrina
K
Kretsinger
D000293:Adolescent; D000328:Adult; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003223:Congo / Q000453:epidemiology; D004196:Disease Outbreaks; D005243:Feces / Q000821:virology; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D010243:Paralysis; D011051:Poliomyelitis / Q000453:epidemiology* / Q000401:mortality / Q000821:virology; D017955:Poliovirus / Q000145:classification / Q000302:isolation & purification; D062486:Public Health Surveillance; D055815:Young Adult