HONG KONG (Reuters) - China vaccinated 4.5 million children and young adults over the last five weeks in the western region of Xinjiang in a fight against polio after the disease paralyzed 17 people and killed one of them, the World Health Organization said.
Polio has broken out in China for the first time since 1999 and scientists say the strain originated from Pakistan. The outbreak marked the latest setback to a global campaign to eradicate polio, now endemic in only four countries — Afghanistan, India, Pakistan and Nigeria.
“Even if they don’t come down with any symptoms (carriers), by giving them polio vaccine we make that person less infectious,” said Oliver Rosenbauer, WHO spokesman for the Global Polio Eradication Initiative in Geneva.
All 17 polio cases occurred in Hotan prefecture in the province of Xinjiang and the patients fell ill between early July and mid-September. The Geneva-based WHO assumes that for every case it finds, there would be 199 others infected with the virus without displaying symptoms, he added.
In large vaccination drives that started in early September, health workers have since vaccinated 4.5 million people with three doses each of the polio vaccine, the WHO said.
Patients and carriers of polio can shed the virus for up to eight weeks in their stools, and transmission occurs through contact with contaminated objects and sewage water. With vaccination, patients and carriers will be infectious for 1-2 weeks.
“We are sensitizing disease surveillance in large hospitals to look for any child or adult displaying polio-like symptoms. We’ll look out for new cases, we hope there won’t be,” he said in a telephone interview.
Polio has flu-like symptoms such as fever, nausea, headache and can result in paralysis within 24 to 72 hours. There is no cure for polio, and doctors only manage their symptoms.
Rosenbauer said polio-free countries will be at risk of reinfection if they do not sustain high immunization rates and without strong political will to eradicate the disease.
“The rest of the world may be polio-free but because it is a communicable disease and people travel, polio-free countries can become reinfected ... this is what we are seeing in western China,” Rosenbauer said.
There have been new 444 cases of polio globally so far this year, a quarter of that in Pakistan. There were 1,349 reported cases in 2010.
“Pakistan - it’s our biggest problem in 2011,” Rosenbauer said. “Just as China can become reinfected, so can polio-free areas in Pakistan become reinfected.”
Eradication efforts are thwarted by conflict as well as logistical and technical problems.
“Vaccinating children during these immunization campaigns more often than not is compromised because of conflict and it is too dangerous for vaccination teams. They have to negotiate with local leaders to obtain safe passage,” Rosenbauer said, referring to southern areas in Afghanistan and tribal areas in Pakistan.
Editing by Yoko Nishikawa