Polio: take care if travelling to Africa or Asia
Polio or poliomyelitis is a highly infectious, virally transmitted disease that often leads to permanent paralysis or even death. Since around 1960, universal vaccination programs have ensured that polio is now very rare in countries in the northern hemisphere. In Switzerland and Germany, for example, according to reliable estimates no cases of polio have been recorded for 20 and 14 years respectively.
For this to remain the case, we need to maintain a vaccination rate among the population of around 90 percent, in other words 90 out of every 100 people must be vaccinated against polio. If these rates should fall, there is a risk that polio will return. Some countries in Africa (above all in the Sub-Saharan region and the Horn of Africa) and Asia (Southeast Asia, mainly India) still have outbreaks of polio. Anyone planning to travel to these regions may be infected there.
How is polio transmitted?
Transmission is from person to person via airborne or contact infection, although the pathogens can also be transmitted through food. Poor hygiene conditions encourage the spread of polio infection.
What are the symptoms of polio?
In 90 to 95 percent of cases there are no particular symptoms, or only a harmless attack of diarrhea. Only in around one percent of illnesses are there signs of paralysis.
How does the disease progress?
The full-blown disease has four stages: In the initial stage, the illness starts with flu-like symptoms such as headache and aching joints, sniffles, bronchitis and temperatures up to 38.5 degrees Celsius (or around 101 degrees Fahrenheit). Sometimes there is diarrhea. The symptoms last for around two days. During stage 2 (called the latent stage) the symptoms disappear for up to three days.
Patients feel well again. In the pre-paralysis stage, there are renewed headaches and pains in the joints, accompanied by fever. Other signs include stiff neck, hypersensitivity, nausea, vomiting, diarrhea and muscle weakness. Paralysis stage: after a further two days, between a half and one percent of patients experience asymmetrically distributed, flaccid paralysis. There is no loss of sensation. In severe cases, the breathing muscles are affected, leading to difficulty in breathing or even apnea. The symptoms of paralysis can disappear altogether.
How long is the incubation period?
Usually between one and two weeks, up to four weeks in exceptional cases. Infectiousness begins around two days after infection and can last for months.
Is there a treatment for polio?
No. Only the symptoms can be treated. In the event of severe breathing paralysis, artificial respiration has to be applied (formerly known as an "iron lung"). Physiotherapy is extremely important in the rehabilitation process.
How do you prevent polio?
By vaccinating the entire population.