Public Health Dispatch: Poliomyelitis - Madagascar, 2002

from Morbidity & Mortality Weekly Report
Posted 07/25/2002

Surveillance for acute flaccid paralysis (AFP) in Madagascar has detected a
cluster of four cases of paralytic poliomyelitis from which type-2
vaccine-derived polioviruses have been isolated. Preliminary data indicate
that these patients, residing in the Tolagnaro district of Toliara province
in southeastern Madagascar, had onset of paralysis during March 20--April 12,
2002. None of the children affected was vaccinated fully. During March--April
2002, provincial authorities conducted a small-scale house-to-house
vaccination response. Genetic sequencing studies of these vaccine-derived
viruses indicate substantial genetic drift and recombination with nonpolio
enteroviruses. These findings are compatible with an outbreak of paralytic
polio associated with a circulating vaccine-derived poliovirus (cVDPV);
however, further investigation is required.
The three outbreaks of cVDPV described previously occurred in areas where
routine oral polio vaccine (OPV) coverage is low, AFP surveillance is
suboptimal, and supplementary vaccination activities have not been conducted
for years [1,2]. Vaccination coverage data suggest that during 1999, 37% of
children aged <1 year had received 3 doses of OPV. In 2001, the nonpolio AFP
rate of 0.3 case per 100,000 population aged <15 years was below the target
level of 1.0.

A joint mission by the Ministry of Health of Madagascar, the Pasteur
Institute of Madagascar, the World Health Organization, and United Nations
Children's Fund (UNICEF) is ongoing to 1) conduct a field investigation of
the cases to verify early reports, 2) review health facility records for any
missed cases, 3) enhance the quality of AFP surveillance nationwide, and 4)
plan for a nationwide house-to-house polio vaccination response. The work of
this mission is being complemented by laboratory work in Madagascar, South
Africa, France, and the United States.

Reported by: Ministry of Health; Pasteur Institute, Madagascar. National
Institute for Communicable Diseases, South Africa. Pasteur Institute, Paris,
France. World Health Organization Regional Office for Africa, Harare,
Zimbabwe. Vaccines and Biologicals Dept, World Health Organization, Geneva,
Switzerland. Div of Viral and Rickettsial Diseases, National Center for
Infectious Diseases; Global Immunization Div, National Immunization Program,


MMWR 51(28):622, 2002. 2002 Centers for Disease Control and Prevention (CDC)

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