Dengue haemorrhagic fever: Virus or host response?

Abstract

The pathogenesis of dengue haemorrhagic fever has been the subject of intense research and considerable controversy. One hypothesisproposes that the immune response in a sensitized host is the primary mechanism. In contrast, others have suggested that the disease is caused by a more virulent, variant strain of dengue virus. Recent advances in molecular biology and hybridoma technology are providing valuable clues toward a solution and illustrating the fact that the course of a human viral disease is often a net result of unseparated interactions between host and virus.So why should the rest of the world be concerned at the plight of the American traveler? Local Donald Pevsners could raise similar hell to have the baggage weight restriction removed universally. It is also worth identifying the offending countries and their airlines as a warning to any traveler, regardless of nationality or destination, that when they check in for their flight they may expect to find strict adherence to the 44-pound weight limit and that the agent will not wink at, say 52 pounds and wave you on, especially in countries that are short of convertible currency. This is a means of gouging a not insignificant amount of extra income from the visitor.The standard excess baggage charge is 1 % of the first-class fare per kilogram. So the extra 20 pounds of baggage that you brought into Bucharest from New York would cost you around $200 to take out again.

Dengue antibodies in blood donors

“…A 1.4% of IgG anti-dengue positive blood bags is not an alarming factor as the donors after such a long time would not transmit the virus to the recipient through transfusions. However, it should be stressed that transmission of IgG anti-dengue antibodies may increase the susceptibility of recipients for immunology conditions, with greater risk of hemorrhagic dengue if they are infected by a second dengue serotype within six months after blood transmission (9,10) . Further, the presence of heterophile antibodies of a previous infection may facilitate the entrance of other viral serotypes.…”

Detection of circulant tumor necrosis factor-alpha , soluble tumor necrosis factor p75 and interferon-gamma in Brazilian patients with dengue fever and dengue hemorrhagic fever

“…In the most severe form of the disease, dengue shock syndrome (DSS), the pulse pressure narrows and circulatory collapse leading to shock occurs (Halstead 1990, PAHO 1994. DHF/DSS is most often associated with a secondary immunological reaction caused by a dengue virus serotype different from that originating the primary infection, in which the immune response is crossreactive but not protective (Pang 1987, Kliks et al 1989 Monocytes/macrophages are considered target cells for dengue infection (Halstead 1980, Anderson et al 1997. These cells may act as antigen-presenting cells and secrete monokines, which participate in T cell activation and production of macrophage activating cytokines.…”

Comparison of dengue infection in human mononuclear leukocytes with mosquito C6/36 and mammalian Vero cells using flow cytometry to detect virus antigen

“…The pathogenesis of dengue disease is not fully understood and is considered an immunopathologic process associated with prior immune sensitization by a heterotypic virus (Halstead 1980 munity, but only transient cross-protection against other serotypes is achieved, making sequential infection possible (Pang 1987, Kliks et al 1989). …”