EPI Newsletter Expanded Program on Immunization in the Americas
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EPI Newsletter Expanded Program on Immunization in the Americas Volume XVI, Number 2 IMMUNIZE AND PROTECT YOUR CHILDREN April 1994 Polio: National Commissions Formed Most of the countries of the Americas have formed One ofthe main concerns of the national commissions Nalional Ccrtification Commissions with the purpose of and the ICCPE will be to review and determine the final overseeing the certification ofthe eradication ofindigenous disposition of cases of AFP that have been classified as transmission ofwild poliovirus. The reports prepared by the compatible with polio. national commissions will be reviewed by the International Certification Commission (ICC) when it convenes in Compatible Cases Washington D.C. in August of 1994. Compatible cases are considered failures of the Each national certification commission is to document surveillance system, because they occur when: and substantiate that the transmission of indigenous wild Two adequate stool specimens were not collected from poliovirus has been interrupted. The reports will provide a a probable case within 2 weeks ofthe bricf history of polio in the .country Polio Compatible Cases by Country, onset ofthe paralysis, Includmg the year the vaCCIne was Latin America and the Caribbean,1993 introduced, previous efforts at con and I Compatible trol, the annual number ofconfirmed Cases there is either an acute paralytic Countries No Follow U~ Reported cases, a summary of the intensified Reported Total illness with polio-compatible residual phase (1985-94) including the date it Losl Died Lale paralysis at 60 days, Bolivia 1 0 0_ 1 was launched, national vaccination ~ or strategies, the structure and organiza Brazil 499 9 0 5 4 tion ofthe program. and yearly OPV3 CAREC 26 2 0 2 0 death lakes place within 60 days, coverage at one year ofage. Colombia 187 4 1 1 2 or Survei lIance for acute flaccid pa Ecuador 67 1 ~ 1 0 the case is lost to follow-up. Guatemala 84 1 1 ralysis (AFP) has been the main tool 0 0 Surveillance of AFP in the of the eradication effort. National Mexico 544 10 2 8 0 countries of the Region during 1993 reports will specify observed trends Nicaragua 49 2 0 2 0 showed that of the 2144 reported Peru since 1985, and include copies of 123 1 0_ 0 1 I cases, 33 were classified as case investigation forms. AFP sur Venezuela 95 2 0 0 2 compatible with polio. Ten of these veillance results will include 1) prob Other 421 I 0 I 0 0 0 were not investigated on time because able cases per year; 2) compatible Total 2144 33 3 20 10 oflate notification, which is a failure cases by year with detailed charts, ofthe surveillance system (see Table). maps, and any other relevant data; 3) Late notification is most often due to discarded cases with their final diagnosis; and 4) confirmed the lack of motivation on the part of attending clinicians, cases per year. whose participation in the reporting system requires further Ten laboratories test the stool samples taken from cases encouragement. PAHO/WI-IO offers a US$IOO.OO reward and their contacts, as well as selected environmental and to providea financial incentive for reporting cases ofparalysis community samples. Ihat prove to be caused by wild poliovirus. In this issue: Polio: National CommissIons Formed ,........ ... , , 1 InJections' Improper Infedjon..conlrol Practices ,. ... ••.. ••••.• 6 Meeting The certification Criteno .. 2 Childhood Immunization and HIV Infection '" , 6 Measles In Canada In 1993 The Lowest Ever Reported... 2 Reported Cases of Selected Diseases. .......•. 7 Vaccines against MenIngococcal Meningitis' Current Status ... ..4 PAHO Establishes AnnuallmmunizatJon Award. ....•.. 6 Twenty ofthe 33 compatible cases were lost to follow up because of death. Death from polio is infrequent; it Measles In Canada In 1993 occurs in 2-10% of cases. It is therefore unlikely that 20 deaths due to polio would occur within a year without a The Lowest Ever Reported major epidemic. Some countries such as Mexico have adopted very strict criteria and classify all AFP cases who have died as compatible. A way to eliminate uncertainty is Canada has sef the rear 200j as fhe date by which it will• to conduct post mortem examinations to determine the eliminate indigenous ,ileasles. [ts coverage and incidence actual cause ofdeath. targets are ro.· Source: Polio Eradication Surveillance System (PESS) f. Achieve and mainlain 97% coverage with the firsf vaccine dose at 2 years ofage by the year 1997. 2. Achie\'e andmainfain 99% vaccine coveragefor the seconddose before school entry by the year 2000. 3. Achie\'e and maintain an incidence of less than 1/ Meeting the Certification 100,000 by fhe year 2000 in each province /territOly. The follml'ing is a re\'iew o/currenf elimination efforfs. Criteria Epidemiologic situation As of October 30. 1993. a provisional total of 174 Good surveillance for acute flaccid paralysis is the measles cases was reported in Canada by the 10 provincial cornerstone of the poliovirus eradication certification and 2 territorial health departments. This is the lowest total process. AFP surveillance data are now being monitored to recorded for the first 10 months ofanv vear since national guide efforts in the Americas. For surveillance to be notification began in 1924. and reflects a 94% decrease considered adequate, the following five criteria must be from the 2.858 cases reported for the same period in 1992. met: The projected incidence for 1993 is 0.7 cases per 100,000. 1. weekly negative notification from at least 80% ofall the lowest ever reported in this country (Figure 1). The weekly reporting units; following summarizes the epidemiologic characteristics of cases reported in 1993 as well as recent developments in 2. detection of a rate of at least 1.0 cases of AFP per prevention and control strategies. 100,000 children under the age of 15; In 1993 no cases were reported from 3 provinces 3. investigation, by a trained epidemiologist, ofat least (Newfoundland. Prince Edward Island and New Brunswic~ 80%ofcases ofAFP, within 48 hours ofnotification; and the 2 territories (Yukon and Northwest Territories., 4. collection oftwo stool specimens within two weeks Ontario and Quebec (representing 62% of Canada's ofparalysis onset, from at least 80% ofAFP cases; population) reported 80% ofthe total cases. In other regions, the numberofcases reported ranged from 1to 17. Compared 5. for at least 80% of AFP cases, collection of stool to 1992, Ontario has experienced a 97% decline, while samples from at least five contacts. Quebec experienced a 23% increase. There has been a remarkable drop in the proportion of Number of Satisfactory AFP Surveillance Indicators, by Country, Latin America, 1994 cases occurring in school-aged children (5 to 19 years), from 83% in 1992 to 53% in 1993. Figure 2 shows the age COUNTRY specific incidence rates per 100.000 population. The highest Chile Colombia rate of infections was among infants. followed by Honduras preschoolers; the rate decreased with increasing age. Venezuela Additional epidemiologic information pertaining to the Ecuador vaccination status ofcases. the proportion ofcases laboratory EI Salvador confirmed, and the proportion ofimported or import-related Peru Bolivia cases is not currently available at the national level. The Cuba latter is not considered a significant problem. With the Dam. Rep. assistance and cooperation ofthe local and provincial public Paraguay Argentina health departments, federal officials are hoping to intensify Haiti the surveillance ofmeasles. moving from the current passive Mexico system to an active one in the near future. Panama Brazil Guatemala Before the introduction ofvaccine, measles occurred in Costa Rica NA 2 to 3- year cycles. The highest incidence was recorded in Uruguay L-~ ._ _ _ 1935 with over 83,000 cases (770/100,000 population). o 1 2 3 4 5 The widespread use ofmeasles vaccine since the mid 1960s NUMBER OF ADEQUATE INDICATORS has resulted in a dramatic reduction in the overall morbidity Efforts to raise AFP surveillance to adequate levels and mortality due to the disease across Canada. The throughout the Americas will be important in reaching the introduction (timing) and implementation ofimmunization goal of certification. The accompanying chart shows programs, vaccine products used, and the vaccine cover. where things stood on 24 March, 1994 in the American over the years has varied greatly among the vario~ Region. jurisdictions. Nevertheless. the immunization programs have 2 been progressively successfl:ll i~ reducing Jhe bur~en Canada's National Advisory Committee on associated with measles, resultIng In 90% to 95 Yo reductIOn Immunization has recentlv endorsed the Consensus in the reported incidence in the last decade. Conference's recommenct"ations, including measles elimination goal and the 2-dose routine immunization In the past decade, despite ongoing.control efforts, strategy. However, the final implementation of these continuina occurrence ofcases ofmeasles In many parts of recommendations will vary depending on the provincial! .hecountry. at irregular inte:vals, and sometimes in ep!demic territorial government and resources. Some provinces are proportions. has been a major concern. Many cases, In fact, already taking steps towards implementing the 2- dose were reported to have a history of measles vaccination, strategy. havina received vaccine according to the national recom~endation,i.e., after 12 months ofage. The generally accepted explanation forthe most recent epidemics in Quebec Figure 2. Measles: Age-Specific Incidence, Canada in 1989. and in Ontario during 1990-1991, includes 1993 (as of Oct 30) insufficient use ofavailable vaccine, sub-optimal vaccination practices and vaccine failures. 4 Measles live vaccine licensed in 1963 A national survey conducted in the spring of 1993 Measles killed vaccine licensed in 1964 indicated that 95% of the 2 to 3- year-olds had received at Measles was not nationally reportable least one dose ofmeasles vaccine, although only 90.5% had 3 between 1959-68 documented evidence ofreceiving the recommended 1dose of vaccine after their first birthday.