32 Lab-Confirmed Cases of Poliovirus in Tajikistan & Tests pending for Remainder of 171 Persons w= ith Acute Flaccid Paralysis syndrome.

Last Thursday (April 29) and Friday (April 30) the World Health Organization (WHO) published the following two updates on the evolving poliovirus outbreak in Tajikistan.

Polio in Tajikistan – Update

29 April 2010 -- 171 cases of acute flaccid paralysis (AFP) have been reported= by the Ministry of Health of the Republic of Tajikistan from January to present. 32 of these cases are confirmed wild poliovirus type 1; results are pending for the remaining cases. The majority of these cases ha= ve an onset of paralysis within the past 3 weeks. There have been 12 deaths.

Of the 32 confirmed wild poliovirus cases, 17 are under the age of two years, = 14 are between the ages of two and five years, and one is between the ages of = six and 15 years. Sixty-six percent are male. To date, 15 of the confirmed polio cases had paralysis onset during March and 17 have had paralysis onset duri= ng April. Information on vaccination history is available for 21 of the 32 confirmed cases. Of these cases, 2 (10%) have reported to have received less than three doses of OPV and 19 (90%) received three or more doses of OPV.

All cases are reported from the south-west of the country, including the capital city Dushanbe. This region borders Afghanistan and Uzbekistan; Genetic sequencing has now determined that the poliovirus is most closely related to virus from Uttar Pradesh, India.

In response to the outbreak, the government of Tajikistan confirmed they are planning three supplementary rounds of immunization targeting every child &= lt;5 years (approx. 1.1 million children). Monovalent oral poliovirus type 1 vaccine will be used to quickly build immunity levels amo= ng children in the country. The first round will begin in the capital Dushanbe and six surrounding districts on May 1 with other regions to begin vaccination of children <5 years on May 4. Two additional national rounds have been tentatively scheduled for 18-22 May and 1-5 June.

Neighboring countries are responding to the outbreak by heightening surveillance at all health care facilities and reporting sites while reviewing immunization sta= tus of children. Uzbekistan (target population 2.89 million children <5 years) is planning two natio= nal rounds of supplementary immunization with effort= s to synchronize these rounds with Tajikistan in May and June. A campaign in Kyrgyzstan to boost the immunity of children against vaccine preventable disease inclu= ding polio, which was planned by the government as part of European Immunization Week, will end tomorrow. Kyrgyzstan is planning to conduct additional sub-national immunization days in defined geographic areas.

WHO maintains its recommendation not to impose restrictions to the international movement of persons as a control measure at this time. It is important that international travelers to and from polio affected areas are adequately immunized against polio as recommended in Chapter 6 of Internati= onal Travel and Health.

[Note (DRL): In the Friday= , 30 April 2010 issue of the WHO’s Weekly Epidemiologic Record (WER) 30 April 2010, 85th year /= 30 April 2010, 85e année No. 18, 2010, 85, 157–164

the following update was published on the situation with regard to poliovirus in Tajikistan:

Poliomyelitis in Tajikistan: first importati= on since

Europe certified polio-free

On 23 April 2010, poliovir= us type 1 was detected in diagnostic samples from cases of acute flaccid paral= ysis (AFP) from Tajikista= n. This represents the first importation of wild poliovirus detected in the WHO European Region since it was certified polio-free in 2002. As of 26 April 2= 010, 168 AFP cases had been reported from Tajikistan since the beginnin= g of the year (at the same time

last year, 35 cases had been reported). In the majority of these cases, onset of paralysis occurred within the past 2 week= s, prompting the government to notify WHO of an outbreak. Ten of the children have died.= The great majority of those affected are children <5 years of age.

Preliminary data suggests = > 45% had received ≥4 doses of oral polio vaccine.

As of 26 April, poliovirus type 1 was isolated in diagnostic specimens from 10 of the AFP cases. All t= he polio cases are located in the south-western part of the country, in an area bordering Afghanistan and Uzbekistan. Afghanistan is one of the 4 remaining polio-endemic countries. No cases have been reported in the areas= of Afghanistan bordering Tajikistan.=

The government of Tajikistan= has requested technical guidance and support from WHO. Vaccine for 3 outbreak response campaigns has been provided through the UNI= CEF Supply Division for Tajikistan. Tajikistan’s last case of clinically confirmed poliomyelitis was in 1997; the last case = of polio confirmed by virological testing was in 1= 991.

Reported nationwide covera= ge with 3 doses of oral poliovirus vaccine (OPV3) was 87% in 2008, the last ye= ar for which comp= lete data are available under the WHO/UNICEF joint reporting process. AFP surveillance indicators in Tajikistan meet certification standards at the national level. In 2009, Tajikistan reported 35 AFP cases, of which none were caused by wild poliovirus. Globally, >90 000 AFP cases were reported in 2009, = of which 1606 were caused by wild poliovirus.

Three AFP cases were reported in Uzbekistan on the Tajikistan border; poliovirus has not yet been isolated from these cases. In addition,= a child from Tajikistan travelled from Dushanbe to Tashkent for medical treatment shortly = after onset of paralysis. The government of Uzbek= istan is planning 2 nationwide rounds of vaccination; the government of Kyrgyzstan is immunizing children <5 years of age during European Immunization Week (26–30 April 2010).

WHO is in communication with countries in the Region about this o= utbreak. It is important that neighboring countries strengthen surveillance for AFP cases, in order to rapidly detect any new importations of wild poliovirus a= nd facilitate a rapid response. Countries should also analyze routine immuniza= tion coverage data to identify any sub-national gaps in population immunity, in order to guide catch-up immunization activities and thereby minimize the consequences of any new introduction of virus. Priority should be given to areas at high risk of importations and where OPV3/DPT3 coverage is < 80%= .

This outbreak demonstrates the need to maintain high population immunity until transmissi= on of poliovirus has been interrupted worldwide. Public health measures such as enhanced surveillance and immunization may be put in place at the borders by the health authorities of Tajikistan and their counterparts in neighboring countries. It is important that international travelers to and from polio-affected areas are adequately immunized against poliomyelitis as recommended in Chapter 6 of Inte= rnational Travel and Health.= 1

WHO does not recommend the imposition of restrictions to the international movement of persons as a control measure at this time. Furth= er information can be found at the following links:

http://www.pol= ioeradication.org/ and http://www.euro.who.int/communicablediseases/outbreaks/20100423_1 

1 See http://www.who.int/ith/ITH2010chapter6.pdf; accessed April 2010.=

WHO documents posted here by:

Daniel R. Luce= y, MD, MPH

EROne Institut= es, Department of Emergency Medicine,

Washington Hospital Center

Department of Microbiology and Immunology

Georgetown University Medical<= /st1:PlaceName> Center

Washington, DC

Website for th= is Newsletter: www.BePast.org

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