MercoPress. South Atlantic News Agency

Dengue fever alert in Paraguay and north Argentina

A case of dengue fever in the northern Argentine province of Formosa has health authorities on alert since a growing number of cases, some deadly, of the disease have been reported in neighboring Paraguay where an epidemics alert has been declared.

The infected man had spent three weeks in Paraguay to visit relatives before crossing back to Formosa where the mosquito transmitted disease was diagnosed. "It' an imported case, since the patient begun experiencing symptoms days before returning to Argentina", said Formosa' Public health and Human Development minister Anibal Gomez. Formosa is 1.200 kilometers north of Buenos Aires but Argentine authorities consider the situation as "grave" and have since last week coordinated strict sanitary controls along the border crossings. Gomez said that provincial authorities have begun a policy of eradicating potential reservoirs (of stagnant water) to eliminate the breeding ground for the Aedes Aegypti mosquito larvae that transmits the disease and in some strains is deadly. Paraguay that has been suffering a string of cases declared this Monday national holiday with the purpose of intensifying the fight against the dengue fever that is rapidly spreading in the country and only this year (2007) has caused the death of three people. The measures are a desperate attempt to prevent the spread of the disease which forced Paraguayan authorities on January 15 to declare an "epidemics" alert nationwide. In the last twelve months 792 cases of classic dengue fever have been confirmed, most of them in the capital Asunción and surrounding areas, and another 854 suspicious cases are waiting for lab tests' confirmation. Last week an outstanding member of the opposition Miguel Martinez Yarves died of the shock caused by the "hemorrhagic" dengue, the most virulent of the strains it was reported in Asunción press quoting the private clinic where he was being treated. "This Monday we begin a massive mobilization to combat the spread of the disease", said Paraguayan National Health minister Oscar Martinez Doldán who said the government was planning to call the Armed Forces to begin a "national fumigation" campaign. Apparently public hospitals in tropical Asunción and surrounding areas are literally flooded with people scared they might have the disease caused by the Aedes Aegypti mosquito. Dengue (DF) and dengue hemorrhagic fever (DHF) are caused by one of four closely related, but antigenically distinct, virus serotypes (DEN-1, DEN-2, DEN-3, and DEN-4), of the genus Flavivirus. Infection with one of these serotypes provides immunity to only that serotype for life, so persons living in a dengue-endemic area can have more than one dengue infection during their lifetime. DF and DHF are primarily diseases of tropical and sub tropical areas, and the four different dengue serotypes are maintained in a cycle that involves humans and the Aedes mosquito. However, Aedes aegypti, a domestic, day-biting mosquito that prefers to feed on humans, is the most common Aedes species. Infections produce a spectrum of clinical illness ranging from a nonspecific viral syndrome to severe and fatal hemorrhagic disease. Important risk factors for DHF include the strain of the infecting virus, as well as the age, and especially the prior dengue infection history of the patient.