Today, Tuesday 24 October, World Polio Day is celebrated. The two Ferrara healthcare companies also participate in the anniversary, underlining the need to maintain adequate surveillance of this infectious disease, and in particular on acute flaccid paralysis, one of the most serious complications of polio. But above all on preventive aspects, linked to the timely and correct administration of the vaccine. In fact today, thanks to extensive vaccination campaigns and surveillance systems, few cases are reported in the world.
One is active in Italy Acute Flaccid Paralysis Surveillance Network (PFA) managed by the Ministry of Health, in collaboration with the Istituto Superiore di Sanità (ISS), which allows the detection and reporting of all cases of flaccid paralysis (due to any etiology) in people under 15 years of age and of every case of suspected poliomyelitis in people of all ages. The Acute Flaccid Paralysis (PFA) surveillance system, with the collection of samples for virological investigations, allows for the timely detection of the possible presence of poliovirus, through the control of pathologies that show symptoms identical to polio. There flaccid paralysis it is a syndrome with a rapid and sudden onset, characterized by paresis or paralysis of the limbs, with possible concomitant involvement of the respiratory muscles and swallowing, which reaches the maximum degree of severity within a few days. The term “flaccid” indicates the absence of spasticity of the affected muscles.
Also THE INFECTIOUS DISEASES OPERATIONAL UNIT OF THE UNIVERSITY HOSPITAL OF FERRARA (directed by Dr. Marco Lebanonre) has participated in the national surveillance of cases of flaccid paralysis for over twenty years. In close collaboration with the “San Giorgio” Rehabilitation Service of the Cona hospital, possible cases with compatible etiology are analysed.
The only prevention weapon for this pathology is represented by polio vaccination. The polio vaccine in use in Italy since 2002 is the one defined as “inactivated”, i.e. based on a chemical process capable of killing the virus without causing it to lose its ability to stimulate the immune system. Polio vaccination, according to the vaccination calendar, involves the administration of 3 doses in the first year of life (in the 3rd, 5th and 11th month), followed by 2 boosters in the 6th and 13th-14th year of life .
For the territory of the province of Ferrara, vaccination is offered free of charge and actively, via invitation letter, by thePUBLIC HYGIENE OPERATIONAL UNIT, RELATIVE TO THE PUBLIC HEALTH DEPARTMENT OF THE FERRARA USL COMPANY – directed by Dr. Clelia de Sisti – in the vaccination sites of Ferrara, Cento, Comacchio, Codigoro, Portomaggiore and Bondeno. Polio vaccination is also offered during consultations for international travellers, when the travel destination is a country in an endemic area.
THE PATHOLOGY. Described in 1789, polio was first recorded as an epidemic in Europe in the early 1800s, later spreading to the United States. In Italy, in 1958, over 8 thousand cases were notified. In our country, polio vaccination has been mandatory since 1966 and the last endemic case of polio occurred in 1982. In 2002, Italy and the entire WHO Europe Region were defined as a “polio-free” region. The reappearance of the disease, however, is always possible, as long as there are areas of the world where the infection is present and widespread. Therefore, surveillance of cases of acute flaccid paralysis, one of the most serious complications of polio, remains active.
Poliomyelitis is an acute, highly contagious infectious diseasecaused by a poliovirus that affects the nervous system, affecting neuronal cells and inducing acute flaccid paralysis which, in the most serious cases, can become fatal. There is no cure for polioif not symptomatic treatments which can only partially minimize the effects of the disease. The only way to avoid potential consequences is prevention through vaccination. There are three forms of paralytic polio:
– the spinal form, the most common one, which is characterized by an asymmetric paralysis and mainly affects the lower limbs;
– the bulbar form, with involvement of the cranial nerves;
– the bulbo-spinal form which represents a combination of the first two.
The polio virus is transmitted from person to person, mainly via the fecal – oral route, as infected subjects eliminate it in the feces for a few weeks; but, initially, for a limited period, the transmission of the virus can also occur orally, via droplets of saliva (for example with a cough or sneeze). Even those who do not show symptoms of polio can transmit the virus.
Most poliovirus infections progress asymptomatically (inapparent forms), while in other cases nonspecific flu-like symptoms occur, such as fever, fatigue, headache, vomiting, constipation (or less commonly diarrhea), neck soreness and pain in the limbs. All these forms regress completely leaving stable immunity. In some cases, however, viral multiplication destroys the motor neurons which do not regenerate, leading to functional incapacity of the affected muscles, even if in some cases it is possible to completely recover muscle function. A small part of infections, around 1 in 200 (according to WHO data), leads to irreversible paralysis, while 5-10% of sufferers die due to paralysis of the muscles of the respiratory system. Paralysis is the most obvious manifestation of the disease, but only 1% of sufferers present this symptom. Diagnosis is often not easy, especially when the symptoms are few and non-specific. It may be suspected in the presence of stiffness of the neck and back with difficulty in flexing the neck, lifting the legs or in case of abnormal reflexes. For diagnostic confirmation it is necessary to take a biological sample (for example phlegm or cerebro-spinal fluid); the search for the virus is carried out above all in stool samples taken in the first days of the disease.
In the photo, from left: Clelia de Sisti, Marco Belgiore