Vigilance and interception, the key to eradicating Polio

(HN July 14, 2010) -- Earlier this month Russia reported six cases of wild poliovirus type 1, the first cases of polio seen in the country in more than 15 years. The polio in Russia was spread from Tajikistan where beginning in April the first case of polio was reported and to date 334 laboratory-confirmed cases and 15 deaths have been confirmed. Three of the cases in Russia were imported, while the other three were found in persons of Tajik ethnicity living in Russia, according to the World Health Organization (WHO).

The outbreak of polio in Tajikistan is the first for the WHO’s Europe office, which encompasses central Asia - since Tajikistan was certified polio-free in 2002.

These statistics would sound devastating in the fight to eradicate polio if it were not for the quick response by the governments in the region. 

In an interview with HUMNEWS, Dr. Rebecca Martin Ph.D. of the WHO’s vaccine, preventable disease and immunization team in Europe said “I feel that we can control this because governments acted quickly, but we have to be vigilant and we can’t have bad coverage”.

Polio case map - courtesy of The World Health Organization

In Tajikistan the government has conducted four rounds of national immunization days, while Uzbekistan, where no cases have been identified but which is thought to be at risk from migration out of Tajikistan, has conducted three rounds of immunization days. In order to ensure no further spread of the virus, the governments of Kazakhstan, Kyrgyzstan and Turkmenistan all have plans to begin rounds of national immunization days beginning this month.

The high vaccination uptake in Tajikistan – now estimated at more than 98% among children under 15, with a large number of adults also seeking vaccination – is the result of “a real fear and panic,” Dr. Martin said. In September Tajikistan will begin a program to administer trivalent vaccines to protect against future importations of other types of poliovirus.

In Russia, where many Tajik’s migrate to work in construction jobs for the summer, officials are immunizing children under the age of 15 arriving from Tajikistan, and have banned imports of dried fruits from that country.

Dr. Martin does not think that the cases of polio in Russia will increase to the level of outbreak seen in Tajikistan. She says, “The immunity wasn’t there in Tajikistan and likely why we saw the high numbers and fast spread – this is not the case in Russia.”

Which begs the question as to why an outbreak happened at all, in a country where immunizing children against polio is official government policy. Dr. Martin said that WHO investigated the possibility of a break in the cold chain that would make supplies of virus ineffective, and that none was found.

She suggests that the likely scenario is that some Tajik children are not registered at birth and slip through the cracks of the system.  Another possibility is that children are only partially vaccinated, receiving only one dose in an intended series.

“The Tajikistan outbreak is a situation in which vigilance went down in area that had been certified polio-free”, says Martin.

WHOs’ overall anti-polio strategy is not likely to change because of the Tajik outbreak, Dr. Martin said. The agency’s stated goal is worldwide eradication by 2012, a goal that Dr. Martin said is not impossible to reach even in light of the current outbreak. “I would say it is in a fragile status and we have to reach the endemic countries – Nigeria, India, Pakistan and Afghanistan. Interception of the transmission of the virus is what needs to happen for polio to be eradicated and the funds need to made available to ensure that this happens.”

The Vaccine

The oral polio vaccine is administered as a series of liquid drops. The vaccines are procured from manufacturers pre-qualified by WHO which sets international standards for their quality. Vaccines purchased from these manufacturers – including from Sanofi-Pasteur and Glaxo Smith Kline are currently in use around the world.

Funding and Support

WHO works in close partnership with UNICEF, the Centers for Disease Control and Prevention (CDC) in the United States of America, the International Federation of Red Cross and Red Crescent Societies, and Save the Children International.

The international effort to bring the polio outbreak under control has received financial support from Rotary International, the United States Agency for International Development (USAID) and the United Kingdom Department for International Development (DFID). WHO and UNICEF are actively mobilizing resources to support the cost of preparedness and response activities.

---- Reporting by Cristina Khalaf