Serodetection of Dengue virus and its antibodies among blood donors in the western region of Saudi Arabia: a preliminary study.

Abstract

Dengue is the most important mosquito-borne viral disease in the world and is endemic in more than 100 countries, with an estimated 100 million infected cases and 25,000 deaths per year worldwide1. Dengue virus (DENV) is caused by a single-stranded RNA virus with five serotypes (DENV-1, DENV-2, DENV-3, DENV-4 and DENV-5)1,2 and its clinical picture ranges from relatively mild Dengue fever, to the life-threatening Dengue haemorrhagic fever/Dengue shock syndrome. In Saudi Arabia, an outbreak of Dengue was reported for the first time in Jeddah during the 1990s3. Next, two peaks of infections were reported during 2005–2006 and another two peaks in 2008. After that, both Dengue disease and its serious haemorrhagic forms became endemic in the Western and Southern regions of the Kingdom4–6. So far, Aedes aegypti remains the mosquito vector most strongly implicated in Dengue transmission and endemicity in this country, although Aedes albopictus is also incriminated6. The potential role of foreign visitors, including pilgrims, who arrive from neighbouring African and Southeast Asia countries with known Dengue endemicity, is also a concern. Millions of visitors come annually from the whole world to the Holy Mecca. Some of these visitors may arrive during their viraemic stage of Dengue infection and, thereby, facilitate the spread of DENV4–6. Emerging infectious diseases still pose threats and risks to the safety of blood products and transfusions. Special attention has recently been paid to the significant role of blood transfusion in the transmission of DENV from asymptomatic infected blood donors to recipients. This form of viral transmission is another source of dissemination and endemicity of the virus in the community7–10. The presence of anti-DENV antibodies is a further important cause of concern in transfusion medicine. It has been proposed that transfusion of blood from donors with circulating non-neutralising or partially neutralising anti-DENV antibodies may increase the susceptibility of recipients to immunological conditions, with these recipients being at a higher risk of haemorrhagic Dengue if they are exposed to a later infection by another DENV serotype within 6 months after the transfusion11. Furthermore, the transmission of heterotypic anti-DENV antibodies from infected blood donors may enhance viral infectivity in recipients who are later exposed to another DENV serotype11. Given the absence of an approved blood screening test for DENV in Saudi Arabia and in response to the new epidemiological situation, the current pilot study was designed to determine the seroprevalence of DENV infection and/or its antibodies among blood donors in the Holy Mecca in order to improve the safety of the blood supply and products in blood donation services in Saudi Arabia.