Dengue fever a growing public health threat
Dengue fever, known as "breakbone fever" because of the excruciating back and joint pain that accompanies this infectious disease, is a growing public health threat for people living in tropical countries, as well as travellers to destinations such as Thailand, Brazil and Puerto Rico, according to research being presented at the annual meeting of the American Society of Tropical Medicine and Hygiene (ASTMH), November 4-7.
Protocol needed to screen blood donors
Dengue, which is believed to infect millions of people annually in developing countries, and also causes some infections in Texas along the border of Mexico, is usually transmitted by mosquitoes. A recent study examined the prevalence of dengue virus among blood donors in Puerto Rico and found that one in every 1,300 donors tested positive during the 2005 epidemic, which means that this sometimes fatal disease might be transferred to others through the blood supply.
"The frequency of finding dengue virus in blood donors during outbreaks is comparable to what we see with West Nile virus," said Susan Stramer, executive scientific officer, American Red Cross. "However, we still need to better understand transfusion-associated transmission of dengue and the dynamics of the virus in donors." Still, the American Red Cross and public health officials plan to start dengue blood donor screening using a research protocol in Puerto Rico in 2008.
Underreporting remains public health concern
Researchers believe that dengue is grossly underreported in many countries. For example, in 2004, 557,000 cases and 1,800 deaths were reported globally to WHO, but the projected dengue burden was more than 8 million cases and nearly 20,000 deaths.
In addition to underreporting, the lack of a rapid and accurate diagnostic test, potential misdiagnoses of milder forms of dengue as influenza, as well as limited data further challenge efforts to measure the global burden of this threatening disease. And, with no drugs available to treat dengue, patients' prognosis relies on good medical management, including rest, fluids and pain relief.
Direct and indirect costs of dengue
In the first comprehensive, multi-country analysis of dengue by all stakeholders (households, employers and public health systems), the new study reveals a substantial epidemiological, social and economic burden associated with the disease.
"On average, a hospitalized case of dengue costs three times that of an ambulatory case," said Jose Suaya, scientist at Brandeis University and co-investigator of the study, which was conducted in eight countries across South East Asia and South America from 2005-2006.
"An episode of dengue has a tremendous impact on the government, households and employers," said Donald Shepard, professor at Brandeis University and co-investigator of the study. "More attention is needed to understand global patterns of dengue and related costs to develop sound policy and appropriately allocate resources for its prevention and treatment. We believe this data is an important first step."
Researchers assessed direct medical costs, non-medical costs and indirect costs (e.g., days lost by patients and caretakers from school, work) and found that even though countries have major public health systems that pay for care, there was a heavy toll on households due to out-of-pocket expenses. For ambulatory patients, families assume most of the burden, and even when someone is hospitalized, they assume about 25% of the related costs.
