The devastating, crippling poliovirus has made a comeback in the Middle East and Africa, sparking a very high level of concern in U.S. health officials who warn that a return of the disease is only an international flight away.
The poliovirus, a RNA virus that was first isolated in 1909 and is one of the most well-characterized viruses, is making a comeback abroad and posing a serious threat in the U.S. that has officials calling for renewed, strict diligence in vaccinating children against this crippling and deadly disease. According to a statement by the World Health Organization’s (WHO) International Health Regulations Emergency Committee, new wild poliovirus infection cases have been documented in Afghanistan, Cameroon, Equatorial Guinea, Ethiopia, Israel, Nigeria, Pakistan, Somalia, and the Syrian Arab Republic. International spread of the virus in 2014 was declared an “extraordinary event” that presents a substantial public health risk to other nations.
Poliovirus is spread primarily by the fecal-oral route and is present in saliva and feces. It causes poliomyelitis, an infection with the virus that if spread to the blood stream can selectively attack and destroy motor neurons, resulting in paralysis or flaccidity in skeletal muscles. Only about one percent of infections enter the blood stream and cause neurological damage. However, the neurological effects of poliomyelitis are permanent. The disease is vaccine-preventable and was eradicated from the U.S. by 1979 through childhood vaccination.
Poliovirus vaccines are still used today. However, in recent years more and more parents have been delaying vaccines or opting to skip them altogether. Poliomyelitis can infect anyone, not just children. In fact, the risk of paralytic poliomyelitis increases alarmingly with age, and adults are at great risk of infection if never vaccinated.
“If there’s a lesson for us here in the United States, it’s that we have to keep vaccinating absolutely every child,” said Dr. William Schaffner, chair of preventive medicine at Vanderbilt University. “If polio is reintroduced into this country, it will find those children whose parents are stretching out their immunization schedules, leaving them susceptible for longer periods of time.”
The WHO Emergency Committee statement identified Pakistan, Cameroon, and the Syrian Arab Republic as the most likely nations to export wild poliovirus. The Committee gave recommendations to these nations and the nations with infections but that are not exporting the virus at present.