The Dengue case reported in the epidemiological update of 7 September has now been discarded based on additional laboratory results.
On 3 August 2012, Greece reported a probable case of dengue infection in a resident in west Greece (Agrinio). This case was classified as a probable dengue case due to the presence of a high titre of IgM dengue antibodies in a serum sample which would indicate an acute infection. In addition, dengue NS1 antigen was detected in serum with PCR, but detection of dengue nucleic acid tests was negative.
Additional laboratory investigations have now discarded this case as a dengue infection. This has been concluded as a rare occurrence of a cross-reaction with murine monoclonal antibodies used in both the IgM antibodies and NS1 antigen testing kits.
In the context of the response to the possible case, the Hellenic Centre for Disease Control (KEELPNO) performed epidemiological and entomological investigations.
The epidemiological investigation included active retrospective and prospective case finding, review of compatible cases, and a survey of people living within a 200m radius of the case and the patient’s relatives.
A total of 132 patients were examined. Ten reported compatible symptoms (such as fever, headache, arthralgias/myalgias, nausea, vomiting or Upper Respiratory Infection in the last 15 days) but all tested negative for IgM and IgG antibodies for dengue virus.