The rapidly growing polio outbreak in Tajikistan raises serious concerns that the disease could spread to other regions in the world, states an editorial in CMAJ (Canadian Medical Association Journal). It is imperative that health agencies attempt to limit further spread by ensuring high vaccination rates.
Polio is a serious disease that can cause paralysis and death in both children and adults. However, vaccines had largely eradicated the disease, until vaccination rates dipped below the minimum 90% coverage mark recommended by the WHO. There is no cure for polio — prevention with vaccines is the only defense.
This is the first persistent outbreak of polio in a country that was previously certified to be polio-free. The outbreak represents 75% of the world's polio cases and far exceeds that of India and Nigeria, which are usually the sources of polio outbreaks.
"Too many regions and communities have ceased to worry about polio," writes Dr. Paul Hébert, Editor-in-Chief, CMAJ with Dr. Noni MacDonald, Public Health Editor. "As a consequence, vaccine uptake rates are all too often well below effective prevention levels."
Countries such as the Ukraine and Georgia are below the 90% target, and regions within Canada and some European countries have low community uptake rates. In Ontario, for example, childhood immunization rates are only in the high 70% to low 80% range, comparable to rates in Tajikistan. Concerns about vaccine safety, anti-government views and religious strictures against vaccinations have contributed to this lower uptake.
Individuals without polio symptoms started the Tajikistan outbreak with cases now appearing in Russia and Uzbekistan. Global travel can hasten the spread of the disease.
Urgent action is needed beyond the mass polio vaccine campaigns now underway in Tajikistan. The WHO must be more proactive in raising awareness of the issue beyond posting the growing numbers on its Global Polio Eradication website. The Public Health Agency of Canada must issue immediate guidance on the importance of polio vaccination, and the provinces and territories need to ramp up programs to improve vaccination uptake rates.
"The threat of polio is no longer simply theoretical," conclude the authors. "We are only one asymptomatic traveller away from an outbreak because of low vaccination rates."