Featured Research

from universities, journals, and other organizations

Polio Outbreak From Oral Vaccine Identified -- And Controlled -- In China

Date:
August 15, 2006
Source:
Infectious Diseases Society of America
Summary:
A 2004 outbreak of polio in China traced back to live attenuated oral polio vaccine (OPV), which is widely used in global eradication efforts, highlights the small but significant risk to eradication posed by the use of OPV at suboptimal rates of coverage. The study, reported in the Sept. 1 issue of The Journal of Infectious Diseases, and now available online, describes the first outbreak of poliomyelitis in China in more than a decade and the first in that country caused by vaccine-derived virus

A 2004 outbreak of polio in China traced back to live attenuated oral polio vaccine (OPV), which is widely used in global eradication efforts, highlights the small but significant risk to eradication posed by the use of OPV at suboptimal rates of coverage. The study, reported in the Sept. 1 issue of The Journal of Infectious Diseases, and now available online, describes the first outbreak of poliomyelitis in China in more than a decade and the first in that country caused by vaccine-derived virus.

This marks the fifth outbreak of vaccine-derived poliomyelitis reported in the world since 2000, the year in which China was certified free of wild-type poliovirus.

The study was conducted in 2004 by Jingjin Yu, MD, and colleagues in Beijing and elsewhere, involving virus isolated from an outbreak in Guizhou province in rural China. Reported national immunization coverage in China is close to 90 percent, but children in the affected area of Guizhou, the poorest province in China, had much lower rates of immunization at the time of the study: only 72 percent of one- to three-year-olds had received at least three doses of the oral vaccine.

The investigators identified six children (three cases and three contacts) in two small towns who had had acute and residual polio-like paralysis and from whom the same type of vaccine-derived poliovirus (type 1) was isolated. A seventh child with paralysis was negative for type 1 virus, but it was found in a close contact of that child. None of the children had been immunized against polio.

Based on the virus strain's known rates of mutation, the finding indicated that the isolates had been circulating for less than a year. This is in contrast to past experience with vaccine-derived strains, which have tended to persist for several years--suggesting how quickly this strain can revert to a paralytic and transmissible form.

Once the outbreak was identified, a province-wide immunization campaign was mounted targeting all children under age 5, with reported coverage of more than 90 percent. To date, the outbreak strain has not been found in any child with polio-like paralysis in the province or elsewhere in China.

In an accompanying editorial, Walter Dowdle, PhD, of the Task Force for Child Survival and Development and Olen Kew, PhD, of the Centers for Disease Control and Prevention, suggest that the China outbreak indicates that vaccine-derived poliovirus can emerge within pockets of lower OPV coverage in countries with overall high levels of immunization and disease surveillance, and that the virus can be contained if identified quickly. They also emphasize the importance of paying close attention to regions that have historically acted as reservoirs of polio, despite the fact that such remote communities as Guizhou were long thought to be unlikely sites for the re-emergence of the virus after eradication because of a lower frequency of exposure.

According to Dowdle and Kew, important questions about the use of oral polio vaccine arise from this outbreak. In 2003, the World Health Organization recommended discontinuing the use of live virus vaccine after the eradication of the disease and containment of poliovirus stocks. But the cost of switching entirely to inactivated polio vaccine would present financial challenges to poor nations, as the cost of the inactivated preparation is estimated at $2.00 to $3.00 per dose, in contrast to 3 cents per dose for the live attenuated oral vaccine. As Yu and colleagues point out, immunization policies will have to be carefully considered in light of both medical and financial concerns.

Founded in 1904, The Journal of Infectious Diseases is the premier publication in the Western Hemisphere for original research on the pathogenesis, diagnosis, and treatment of infectious diseases; on the microbes that cause them; and on disorders of host immune mechanisms. Articles in JID include research results from microbiology, immunology, epidemiology, and related disciplines. JID is published under the auspices of the Infectious Diseases Society of America (IDSA). Based in Alexandria, Va., IDSA is a professional society representing about 8,000 physicians and scientists who specialize in infectious diseases. For more information, visit www.idsociety.org.


Story Source:

The above story is based on materials provided by Infectious Diseases Society of America. Note: Materials may be edited for content and length.


Cite This Page:

Infectious Diseases Society of America. "Polio Outbreak From Oral Vaccine Identified -- And Controlled -- In China." ScienceDaily. ScienceDaily, 15 August 2006. <www.sciencedaily.com/releases/2006/08/060815160951.htm>.
Infectious Diseases Society of America. (2006, August 15). Polio Outbreak From Oral Vaccine Identified -- And Controlled -- In China. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2006/08/060815160951.htm
Infectious Diseases Society of America. "Polio Outbreak From Oral Vaccine Identified -- And Controlled -- In China." ScienceDaily. www.sciencedaily.com/releases/2006/08/060815160951.htm (accessed July 25, 2014).

Share This




More Health & Medicine News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins