Eradicating poliomyelitis: India's journey from hyperendemic to polio-free status
نویسندگان
چکیده
India's success in eliminating wild polioviruses (WPVs) has been acclaimed globally. Since the last case on January 13, 2011 success has been sustained for two years. By early 2014 India could be certified free of WPV transmission, if no indigenous transmission occurs, the chances of which is considered zero. Until early 1990s India was hyperendemic for polio, with an average of 500 to 1000 children getting paralysed daily. In spite of introducing trivalent oral poliovirus vaccine (tOPV) in the Expanded Programme on Immunization (EPI) in 1979, the burden of polio did not fall below that of the pre-EPI era for a decade. One of the main reasons was the low vaccine efficacy (VE) of tOPV against WPV types 1 and 3. The VE of tOPV was highest for type 2 and WPV type 2 was eliminated in 1999 itself as the average per-capita vaccine coverage reached 6. The VE against types 1 and 3 was the lowest in Uttar Pradesh and Bihar, where the force of transmission of WPVs was maximum on account of the highest infant-population density. Transmission was finally interrupted with sustained and extraordinary efforts. During the years since 2004 annual pulse polio vaccination campaigns were conducted 10 times each year, virtually every child was tracked and vaccinated - including in all transit points and transport vehicles, monovalent OPV types 1 and 3 were licensed and applied in titrated campaigns according to WPV epidemiology and bivalent OPV (bOPV, with both types 1 and 3) was developed and judiciously deployed. Elimination of WPVs with OPV is only phase 1 of polio eradication. India is poised to progress to phase 2, with introduction of inactivated poliovirus vaccine (IPV), switch from tOPV to bOPV and final elimination of all vaccine-related and vaccine-derived polioviruses. True polio eradication demands zero incidence of poliovirus infection, wild and vaccine.
منابع مشابه
Poliomyelitis: Current Status in Iran and Worldwide
Poliomyelitis (polio) is a highly infectious viral disease, which mainly affects young children. The virus is transmitted by person-to-person spread mainly through the faecal-oral route or, less frequently, by a common vehicle (e.g. contaminated water or food) and multiplies in the intestine, from where it can invade the nervous system and can cause paralysis. Initial symptoms of polio include ...
متن کاملThe Surveillance System of Poliomyelitis/Acute Flaccid Paralysis in the Islamic Republic of Iran: History, Structures and Achievements
Background and Objectives: : According to the global strategy for polio eradication, targeted surveillance of the disease is one of the main tasks of the health system. The purpose of this study was to review the status and surveillance of poliomyelitis/acute flaccid paralysis (AFP) in Iran. Methods: The present study was a review on the processes, structures and achievements of the poliomy...
متن کاملAlarm of Circulating Wild Poliovirus and Of Vaccine-Derived Poliovirus in Middle East Countries as a Potential Risk for Re-Emerging of Polio in Iran
Poliomyelitis is a highly infectious viral disease which is mainly transmitted via contaminated food and drinking water by human feces, especially in situations of poor hygiene and sanitation (1). This disease is caused by 3 types of wild poliovirus (WPV) (types 1, 2 and 3), and immunity against one type does not create immunity against other types. In our country according National Immuni...
متن کاملPrioritizing polio.
www.vi-vi.org We are only US$945 million short of successfully eradicating poliomyelitis: here, a case for why polio eradication should be made a priority worldwide is made – a proposal that is both economically viable and important for health care initiatives in the future. With only 128 cases reported in 2012 (by 6 September 2012) compared with 356 in 2011, we have come closer than ever befor...
متن کامل