The emergency call came as officials reported that polio had been detected in sewage samples taken at different locations and times in two counties in upstate New York, possibly signaling the spread of the disease in the community. “Based on past polio cases, New Yorkers should be aware that for every one case of paralytic polio seen, there may be hundreds of other people who are infected,” said Dr. Mary T. Bassett, the state’s health commissioner, in a statement. . “Combined with the most recent sewage findings,” added Dr. Bassett, “the department is treating the single case of polio as just the tip of the iceberg of a much larger potential spread.” Polio is caused by the polio virus, and children under 5 are most at risk of contracting it, but anyone who isn’t vaccinated is at risk. Polio is highly contagious, usually spread from person to person when someone comes in contact with the feces of an infected person and then touches their mouth.
The fight against polio
The highly contagious virus was one of the most feared diseases until the 1950s, when the first vaccine was developed.
Many cases are asymptomatic and some may cause flu-like symptoms, but the disease, also known as poliomyelitis, can be disabling and even life-threatening. There is no treatment. Paralysis is a rare result, but before vaccines were widely available in the 1950s, polio outbreaks caused more than 15,000 cases of paralysis a year. Last month, a case of polio — the first reported in the United States in nearly a decade — was traced to an unvaccinated adult man in Rockland County. No cases had occurred in the United States since 1979. State and county health officials said the infection in Rockland County was spread by someone who received the oral polio vaccine, which has not been given in the United States since 2000. The virus circulating in New York may have come from outside the United States, where the oral vaccine is still administered, officials said. The oral vaccine contains weakened virus. It is safe, but if the virus from the vaccine circulates in a community, it can infect unvaccinated people and spread the disease. In announcing the case, officials stressed that the infected person was no longer contagious and said their efforts would focus on increasing vaccination rates and determining whether anyone else may have been affected. Officials said polio had been found in Rockland County sewage samples taken in June, before the polio case was confirmed. On Thursday, they said evidence of the disease was also found in sewage samples taken in June and July from two “geographically distinct” parts of Orange County, which is adjacent to Rockland. “The findings,” the state health department said in a news release, “provide further evidence of local — not international — transmission of the polio virus.” There was no indication that the infected man in Rockland County was the source of the polio found in the sewage samples, officials said. The investigation into the origin of the virus continues. Because widespread vaccination has been shown to be an effective prevention strategy, areas with low immunization rates may be at particular risk of outbreaks. In both Rockland and Orange counties, about 60 percent of 2-year-olds have received all three doses of the polio vaccine, according to state data — a much lower rate than the 80 percent in the rest of the state, excluding New York. (To achieve herd immunity for polio, the target vaccination rate is 80 percent, according to the World Health Organization.) Most adults in the United States do not need to be vaccinated against polio because they were probably vaccinated as children, although some may be eligible for booster shots if they have an increased risk of exposure.
