Rome (Fides Service) – Recently a group of American researchers who monitor epidemics of Dengue fever dengue undertook a study of the waves of this disease which invade the planet. They started with Thailand and continued with other countries and have reached the conclusion that the disease radiates externally in a progressive wave from Bangkok, the largest city, to infect every province in the country. According to the researchers the wave travels at a speed of 148 km per month and takes about 8 months to spread all over the country.
Dengue fever is carried by mosquitoes and every year it infects between 50 million and 100 million people including children. Serious epidemics of the most lethal form of Dengue cause a crisis in national health services.
Most patients develop fever and muscle pains which last for about a week. For those who are infected repeatedly the situation is much more critical: fever, haemorrhaging and heavy internal bleeding damage the liver. The strange thing is that the dengue virus exists in four different varieties and immunity to one type would seem to make infection from another type even more dangerous.
In Thailand, cases of Dengue vary from year to year. Between 1983 and 1997 some 850.000 cases were registered.
(AP) (28/1/2004 Fides Service; lines:23 words:273)