Tag Archives: polio

Progress Toward Eradication of Polio — Worldwide, January 2011–March 2013

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United States Cen­ters for Dis­ease Con­trol and Pre­ven­tion. MMWR. 3 May 2013. 62(17):335–338.
Avail­able at http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6217a4.htm

Excerpt. In May 2012, the World Health Assem­bly of the World Health Orga­ni­za­tion (WHO) declared the com­ple­tion of polio erad­i­ca­tion a pro­gram­matic emer­gency. Since the launch of the Global Polio Erad­i­ca­tion Ini­tia­tive (GPEI) in 1988, the num­ber of annual polio cases has decreased by >99%. As of March 2013, cir­cu­la­tion of indige­nous wild poliovirus (WPV) con­tin­ued in only three coun­tries: Afghanistan, Nige­ria, and Pak­istan (the last case in India had onset in Jan­u­ary 2011). This report pro­vides an update on progress toward global polio erad­i­ca­tion dur­ing Jan­u­ary 2011–March 2013, using data reported as of April 23, 2013. The num­ber of WPV cases reported glob­ally decreased 66%, from 650 in 2011 to 223 in 2012; WPV cases decreased 53% (from 80 to 37) in Afghanistan and 71% (from 198 to 58) in Pak­istan, but increased 97% (from 62 to 122) in Nige­ria. The num­ber of imported WPV cases in pre­vi­ously polio-free coun­tries decreased from 309 in 12 coun­tries in 2011 to six in two coun­tries in 2012. Dur­ing January–March 2013, a total of 22 WPV cases were reported world­wide, com­pared with 48 cases dur­ing the same period in 2012. An esti­mated 2.05 bil­lion doses of oral poliovirus vac­cine (OPV) were admin­is­tered in 2012 to approx­i­mately 448 mil­lion per­sons, pri­mar­ily chil­dren aged <5 years, in sup­ple­men­tal immu­niza­tion activ­i­ties (SIAs) con­ducted in 46 coun­tries. SIAs were tem­porar­ily sus­pended in areas of Pak­istan and Nige­ria after attacks against health work­ers occurred in Decem­ber 2012 and the first quar­ter of 2013. The num­ber of con­firmed WPV cases has decreased to the low­est level ever, but secu­rity con­cerns con­tinue to threaten the over­all goal of global eradication.

Egypt: Importation of wild poliovirus detected in environmental (sewage) samples

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Wild poliovirus has been found in sam­ples taken from sewage in Al Hag­gana (Nasr City) and Al Salam dis­trict in Cairo. The wild poliovirus is related to the wild poliovirus type 1, from north Sindh, Pak­istan, which was reported in Sep­tem­ber 2012.

This is the first doc­u­mented impor­ta­tion of wild poliovirus from Pak­istan, after Egypt was declared polio free, with its last case in May 2004. At this stage, there are no cases (chil­dren) of paral­y­sis asso­ci­ated with this importation.

These poliovirus strains have been detected through ongo­ing envi­ron­men­tal sur­veil­lance in Egypt, which involves reg­u­lar test­ing of sewage water from mul­ti­ple sites (total in the coun­try 34, in Cairo 5).

Emer­gency response and coor­di­na­tion efforts are ongo­ing between the Min­istry of Health and Pop­u­la­tion, the Gov­ern­ment of Egypt and the Global Polio Erad­i­ca­tion Ini­tia­tive part­ners, WHO and UNICEF. Teams have been sent to each of the areas in which the virus was detected in envi­ron­men­tal sam­pling and a field inves­ti­ga­tion and active search for cases is ongo­ing. The fre­quency of envi­ron­men­tal sam­pling has been increased; envi­ron­men­tal sam­ples will be col­lected fort­nightly instead of monthly from the five sites located in Cairo.

Sup­ple­men­tary immu­niza­tion activ­i­ties are being planned for a large-scale Cairo-wide cam­paign for chil­dren under 5 years of age, tar­get­ing approx­i­mately 3 mil­lion chil­dren. The cam­paign is planned dur­ing the com­ing month; dates have not yet been final­ized. Imme­di­ate response vac­ci­na­tion in these two areas has been strongly rec­om­mended to the Min­istry of Health and Population.

Mean­while, in a joint state­ment, WHO, UNICEF and the Polio Mon­i­tor­ing Cell in Pak­istan have announced this sit­u­a­tion as crit­i­cal and alarm­ing for the polio pro­gramme in Pak­istan. The state­ment fur­ther adds that chil­dren under the age of five depart­ing Pak­istan will be given polio drops at spe­cial coun­ters at the air­ports.
(WHO 1/18/2013)

Comparative seroepidemiology of pertussis, diphtheria and poliovirus antibodies in Singapore: Waning pertussis immunity in a highly immunized population and the need for adolescent booster doses

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Lai FY, Thoon KC, Ang LW, et al. Vac­cine. 1 April 2012. doi:10.1016/j.vaccine.2012.03.059.
Avail­able at http://www.sciencedirect.com/science/article/pii/S0264410X12004513

Back­ground. We assessed the sero­epi­de­mi­ol­ogy of per­tus­sis, diph­the­ria and poliovirus anti­bod­ies in a cohort of highly immu­nized chil­dren, together with the bur­den of these dis­eases in Singapore.

Meth­ods. Hos­pi­tal resid­ual sera col­lected between August 2008 and July 2010 from 1200 chil­dren aged 1–17 years were tested for the preva­lence of IgG anti­bod­ies against Bor­de­tella per­tus­sis, diph­the­ria tox­oid, and all three poliovirus types by enzyme-linked immunosor­bent assays.

Results. We found an over­all sero­preva­lence of 99.4% (95% CI 98.8–99.7%) for diph­the­ria, and 92.3% (95% CI 90.6–93.6%) for poliomyelitis, along with no indige­nous cases of these dis­eases since 1993. How­ever, the sero­preva­lence for per­tus­sis was 60.8% (95% CI 58.0–63.5%) only. Among the sub­jects who had com­pleted three doses of per­tus­sis vac­ci­na­tion by the age of 2 years (n=1092), the per­tus­sis sero­preva­lence was 85.0% (95% CI 79.7–89.2%) in those who received the last vac­ci­na­tion within a year before the study, and it decreased to 75.0% (95% CI 64.5–83.2%) and 63.1% (95% CI 50.9–73.8%) in those who had the last vac­ci­na­tion 1 year and 2 years before the study, respec­tively. The sero­preva­lence remained at about 50% for those whose last per­tus­sis vac­ci­na­tion was admin­is­tered 4 years and longer before the study.

Con­clu­sions. The high sero­preva­lence for poliomyelitis and diph­the­ria con­fer solid herd immu­nity to elim­i­nate these dis­eases in Sin­ga­pore. In con­trast, immu­nity against per­tus­sis waned con­sid­er­ably over time, and rou­tine boost­ers should be given to ado­les­cents to ensure sus­tained immu­nity against pertussis.