On March 23, 1999, the Pediatric Hospital in Luanda, Angola, reported 21 cases (three deaths) of acute flaccid paralysis (AFP). By April 3, 102 AFP cases had been reported in Luanda and neighboring areas of Bengo province. A preliminary investigation by the Ministry of Health (MOH) indicated that these cases primarily occurred among children aged <5 years; 90% had received two or fewer doses of oral poliovirus vaccine (OPV), 4% had received three doses, and 6% had received four doses. Many case-patients resided in overcrowded municipalities where families displaced by civil war had settled. On the basis of preliminary data, MOH suspected the outbreak was poliomyelitis and began planning a vaccination campaign to control the epidemic. Surveillance was strengthened to identify and rapidly investigate reports of AFP cases to determine the extent of the outbreak. (+info)
In 1988, the World Health Assembly resolved to eradicate poliomyelitis globally by 2000. To achieve this goal, the African Region (AFRO) of the World Health Organization (WHO) has accelerated polio eradication strategies, but the region remains one of the two major reservoirs for wild poliovirus transmission. This report summarizes progress toward polio eradication from 1998 through April 1999 in AFRO, highlights supplementary vaccination activities (National Immunization Days [NIDs]) and acute flaccid paralysis (AFP) surveillance conducted in the region, and describes plans for program acceleration (intensified NIDs and mopping-up vaccinations) to meet the 2000 eradication target. (+info)
Comparison of enterovirus-specific cellular immunity in two populations of young children vaccinated with inactivated or live poliovirus vaccines.
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Enterovirus-specific cellular immunity was studied in Estonian and in Finnish children at the age of 9 months. The aim was to evaluate the level of responsiveness in two neighbouring countries with different poliovirus immunization practices and striking differences in the incidence of insulin-dependent diabetes mellitus (IDDM), a disease in which early enterovirus infections are an aetiological risk factor. The Estonian children immunized with live attenuated polio vaccine had stronger T cell responses to coxsackievirus B4 and poliovirus type 1 when compared with Finnish children immunized with inactivated polio vaccine (median stimulation indices 10.4 and 6.3 in Estonian children and 1.9 and 2.9 in Finnish children, respectively; P < 0.05). Lymphocytes stimulated by poliovirus type 1 antigen expressed interferon-gamma (IFN-gamma) mRNAs, which strongly correlated with the level of proliferation responses. Lymphocytes of Estonian children had a tendency towards stronger expression of IFN-gamma upon poliovirus challenge when compared with Finnish children. The number of children who had experienced coxsackievirus B infections, as determined by the presence of neutralizing antibodies, did not differ between Estonian and Finnish children. The results show that Finnish children have weaker cellular immunity against enteroviruses at the age of 9 months compared with Estonian children at the same age. This is most probably due to the difference in polio vaccination schedules; in Estonia live poliovirus vaccine is used and given at earlier ages than the inactivated vaccines in Finland. This leads to stronger T cell immunity which cross-reacts with other enterovirus serotypes. This may explain the lower incidence of IDDM in Estonia by providing effective protection against diabetogenic enterovirus strains in Estonian children. (+info)
Oral iodine supplementation does not reduce neutralizing antibody responses to oral poliovirus vaccine.
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Iodine deficiency is a major cause of impaired mental development, goitre, and cretinism in many parts of the world. Because existing immunization programmes can be used to deliver oral iodized oil (OIO) to infants at risk, it was important to know whether OIO could adversely affect the antibody response to vaccines, such as trivalent oral poliovirus vaccine (OPV). A randomized, double-blind, placebo-controlled clinical trial was conducted in Subang, West Java, Indonesia, in which 617 eight-week-old infants received either OIO or a placebo (poppy-seed oil) during a routine visit for their first dose of OPV as part of the Expanded Programme on Immunization (EPI). The infants received two boosters of OPV at 4-week intervals after the first dose, and were followed up when 6 months old. Neutralizing antibody titres to poliovirus serotypes 1, 2, and 3 were compared in serum samples that were taken from 478 of these infants just before the first dose of OPV and at 6 months. It was found that oral iodized oil did not reduce the antibody responses to any of the three serotypes of OPV. These results indicate that oral iodine may safely be delivered to infants at the same time as oral poliovirus vaccine according to current EPI immunization schedules. (+info)
Outbreak of poliomyelitis--Kunduz, Afghanistan, 1999.
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Since May 10, 1999, 26 cases of acute flaccid paralysis (AFP), including five cases with isolation of wild poliovirus type 1 and one with type 3, have been reported from Kunduz province in northern Afghanistan. Fifteen (54%) case-patients resided in Kunduz city, and the remaining patients resided in the districts surrounding Kunduz. Although the exact causes for the outbreak are not known, the discontinuation of polio vaccination activities in mid-1997 in northern Afghanistan because of ongoing civil conflict may have facilitated the outbreak. (+info)
Progress toward the global interruption of wild poliovirus type 2 transmission, 1999.
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Since 1988, when the World Health Assembly resolved to eradicate poliomyelitis globally by 2000, substantial progress has been made in attaining this goal: the Americas, the Pacific Rim, Europe, and central Asia appear to be polio-free. The remaining reservoirs where polio is endemic are confined to India and contiguous countries and to sub-Saharan Africa. In 1999, the recommended polio eradication strategies (i.e., achieving and maintaining high routine vaccination coverage with oral poliovirus vaccine [OPV]; conducting National Immunization Days [NIDs] to decrease rapid poliovirus circulation; establishing sensitive surveillance systems for polio cases and poliovirus; and carrying out mopping-up vaccination activities to eliminate poliovirus transmission) have been accelerated in most of the major reservoir countries. This report summarizes progress toward interrupting transmission of wild poliovirus type 2, which appears to be on the threshold of extinction. (+info)
In 1988, the World Health Assembly adopted a resolution to eradicate poliomyelitis globally by 2000. During the same year, the Regional Committee, Eastern Mediterranean Region (EMR) of the World Health Organization (WHO) resolved to eradicate polio from the region by 2000. Substantial progress in reaching this goal has been made globally and in countries of EMR. This report describes the current status of polio eradication in Afghanistan, a country in EMR with ongoing civil conflict where eradication efforts began in late 1994. (+info)
Eradication of poliomyelitis in Cuba: a historical perspective.
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The eradication of poliomyelitis in Cuba, for which effective vaccines had to be acquired, is reviewed in this article. The strategy for eradication was based on mass immunization campaigns for the annual delivery of two doses of trivalent Sabin oral poliovirus vaccine (OPV). Except during the first campaign in 1962, the ages of the children for immunization were determined through national serological surveys of the entire country, including rural and urban areas. The interruption of wild virus transmission had been suspected since 1967 in Cuba, and since 1970 no studies have detected any wild virus. The important role of political and social organizations in the success of the programme and in the execution of the mass immunization campaigns is underscored. Countries that have successfully interrupted poliovirus circulation should maintain high immunization coverage for as long as there are other countries in the world where poliovirus still exists. (+info)