Poliomyelitis – Overview:
World Polio Day on 24th October every year is aimed at increasing awareness about poliovirus and to encourage further actions to reduce it from spreading. The commemoration of the day also highlights the success of global strategies in reducing the spread of the disease.
Polio is a highly infectious disease that targets the nervous system and can cause paralysis. Experts say that as long as polio threatens even one child anywhere in the world, children everywhere remain at risk. Lets understand in detail about this dreaded virus and its mode of transmission.
Poliomyelitis, often called polio or infantile paralysis, an acute viral infectious disease spread from person to person, primarily via the fecal-oral route. The term derives from the Greek word polios, meaning “grey”, myelos, referring to the “spinal cord”, and the suffix -itis, which denotes inflammation.
Although around 90% of polio infections cause no symptoms at all, affected individuals can exhibit a range of symptoms if the virus enters the blood stream. In about 1% of cases the virus enters the central nervous system, preferentially infecting and destroying motor neurons, leading to muscle weakness and acute flaccid paralysis. There are different types of paralysis that may occur, depending upon the nerves involved. Spinal polio is the most common form of polio affecting children, characterized by asymmetric paralysis that most often involves the legs. Bulbar polio leads to weakness of muscles innervated by cranial nerves. Bulbospinal polio is a combination of bulbar and spinal paralysis.
In the year 1840, Jakob Heine was the to first recognize poliomyelitis as a distinct condition. Later in the year 1908 poliovirus, was identified by Karl Landsteiner.
Although major polio epidemics were unknown before the late 19th century, polio was one of the most dreaded childhood diseases of the 20th century. Polio epidemics have crippled lives of thousands of people, mostly young children; the disease has caused paralysis and death for much of human history. Polio had existed for thousands of years quietly as an endemic pathogen until the 1880s, when major epidemics began to occur in Europe; soon after, widespread epidemics appeared in the United States of America.
By 1910, much of the world experienced a dramatic increase in polio cases and frequent epidemics became regular events, primarily in cities during the summer months. These epidemics left thousands of children and adults paralyzed, this provided the impetus for a “Great Race” towards the development of a vaccine and various polio eradication programs. The polio vaccine was developed in the 1950s; polio vaccines are credited with reducing the global number of polio cases. Enhanced vaccination efforts led by the World Health Organization, UNICEF, and Rotary International have paved its way in for global eradication of this dreaded disease.
Poliomyelitis is believed to be a highly contagious disease that spreads easily by human-to-human contact. In endemic areas, wild polioviruses can infect virtually the entire human population. It is seasonal in temperate climates, with peak transmission occurring in summer and autumn seasons especially. These seasonal differences are far less pronounced in tropical areas. The time between first exposure and first symptoms, known as the incubation period, is usually 6 to 20 days, with a maximum range of 3 to 35 days.
Virus particles are excreted in the feces for several weeks following initial infection. The disease is transmitted primarily via the fecal-oral route, by ingesting contaminated food or water. It is occasionally transmitted via the oral-oral route, a mode especially visible in areas with good sanitation and hygiene. Polio is most infectious between 7–10 days before and 7–10 days after the appearance of symptoms, but transmission is possible as long as the virus remains in the saliva or feces.
Lets play our part as responsible citizens in eradicating this dreaded disease, so that the future generations doesn’t suffer and curse its forefathers for being irresponsible.
Two drops to life…