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 (CDC), 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 to $3 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.
Source: Infectious Diseases Society of America (IDSA)
Dear Helpdesk: Working in a Toxic Health Care Environment
March 28th 2024Dear Helpdesk is your steadfast companion, offering life coaching and workplace advice from 2 seasoned IPs for some of your most challenging real-life situations. Let us help you navigate the intersection between work and life, guiding you to navigate the dynamic world of infection prevention with confidence and grace. This article is on handling a toxic health care environment.
Product Locator: Spring and Early Mother's Day Gift Guide for Infection Prevention Personnel
March 27th 2024Whether it's a spring holiday, birthdays, or no reason at all, infection prevention personnel love to give and receive gifts that help at the end of a stressful day. Infection Control Today® offers some gift ideas for infection prevention personnel and their families.
Catching Up With Vangie Dennis, AORN 2022-2023 President at AORN 2024
March 26th 2024Infection Control Today (ICT) had the privilege of catching up with Vangie Dennis, MSN, RN, CNOR, CMLSO, at the Association of periOperative Registered Nurses' (AORN’s) International Surgical Conference & Expo 2024. As the former president of AORN and an esteemed figure in perioperative services, Vangie Dennis shared insights into her recent endeavors and the exciting new chapter she's embarked upon.
How To Optimize Your Time Management Strategies for the Busy Infection Preventionist
March 25th 2024Is your calendar resembling a chaotic masterpiece of overlapping tasks? Join the club of infection preventionists striving to balance responsibilities. Dive into proven strategies from a fellow infection preventionist to reclaim control of your time, streamline tasks, and boost productivity effectively. This is an IP Lifeline article.