Polio virus, illustration. Each viral particle consists of a protein envelope around a core that contains the genetic material for RNA. This virus infects children and causes polio, or polio.
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The New York State Department of Health confirmed a case of polio on Thursday, the first known infection in the United States in nearly a decade.
A resident of Rockland County, a suburb of New York City, has tested positive for polio, according to the state health department. The Centers for Disease Control and Prevention confirmed the infection.
State health officials said health care providers should look for additional polio cases. The chain of infection that led to the New York case is believed to have originated outside the United States, and polio cases have not originated in the United States since 1979, according to the CDC.
The strain of polio the person was infected with, known as Sabin virus type 2, indicates that the chain of infection began with a person who received the oral polio vaccine, according to the state health department. The oral polio vaccine contains a mild viral strain that is still able to replicate, which means that people who receive it can pass the virus to others.
The oral polio vaccine is no longer given in the United States, indicating that the chain of transmission has begun overseas, according to New York health officials. The United States uses an inactivated polio vaccine that is given as an injection into the leg or arm. This vaccine uses a non-reproductive viral strain so that people who receive it cannot pass the virus on to others.
The CDC recommends that all children receive the polio vaccine. New York State requires that all children receive the shot before school starts.
Polio is highly contagious and often begins with flu-like symptoms such as fatigue, fever, headache, muscle aches, vomiting, and stiffness. Symptoms can take up to 30 days to appear, which means that people who haven’t gotten sick yet can still pass the virus on to others.
In rare cases, polio can cause paralysis and death. The virus caused widespread fear in the 1940s before vaccines were available, with more than 35,000 people disabled from polio each year, according to the CDC. At the time, many parents were afraid to let their children play outside during the summer when transmission peaked.
However, a successful national vaccination campaign in the 1950s and 1960s significantly reduced the number of infections. The United States became polio-free by 1979.
The United Kingdom declared a national incident in late June after polio was detected in several sewage samples in London. UK wastewater samples tested positive for the virus strain used in vaccines.