Clinical response in patients with dengue fever to oral calcium plus vitamin D administration: study of 5 cases.

A dengue epidemic is one of the most important public health problems in the tropical and subtropical areas of the World. In 2005, 7,062 dengue cases were reported in Tamaulipas on Mexico's eastern coast, including 1,832 (26%) cases classified as Dengue Hemorrhagic Fever (DHF). Dengue fever (DF) is characterized by fever, intense headache, myalgias, arthralgias, rash, nausea and vomiting. A proportion of infected persons may develop DHF characterized by prominent hemorrhagic manifestations associated with thrombocytopenia. An immune mechanism of thrombocytopenia due to increased platelet destruction appears to be operative in patients with DHF. Excessive capillary permeability may lead to Dengue Shock Syndrome (DSS). Patients with DHF/DSS who also have prolonged fever (> 5 days) are at high risk for concurrent bacteremia. Standard treatment is limited to electrolytic solutions, rest, measurements of body temperature, blood pressure, hematocrit, platelet count, and administration of antipyretics like paracetamol when fever is too high. Extracellular calcium plays a key role in platelet aggregation and for the regulation of the immune response in personsinfected with Dengue Virus (DV), and dihydroxy-vitamin D has recently been found to alter IL-12 expression anddendritic cell maturation. We report the cases of five patients who received oral calcium carbonate plus Vitamin D3, who improved overall clinical condition and reduced the duration of signs and symptoms of DF.

Oral calcium administration attenuates thrombocytopenia in patients with dengue fever. Report of a pilot study.

Global climate change is one of the instigating and contributing factors for epidemic outbreaks of infectious diseases in human populations. In the years 2003 to 2005 the city of Tampico, in the northern state of Tamaulipas, Mexico, experienced recurrent outbreaks of dengue virus infections (DV) and the resulting dengue fever (DF). One of the hallmark symptoms of DF, which appears to worsen as the environmental temperature increases, is thrombocytopenia. In as much as it is a hallmark for hemorrhagic manifestations, thrombocytopenia is a useful sign to monitor the course of infected patients. Extracellular calcium (Ca2+ o) plays a key role in blood clotting; its chelation in vitro with ethylenediaminetetracetic acid (EDTA) or citrate prevents clotting, while exogenous recalcification of plasma leads to shortening of clotting time. In vivo, Ca2+ o is essential for platelet function and for the regulation of the immune response. In this work we report a significant increase (p<0.05) in the number of blood platelets of patients with clinical signs and symptoms of DF following oral administration of calcium carbonate (CAL, 1.2 to 1.8 g/day; n=10) when compared with a control group (CTL, n=10): 89 (46-132) versus 206 (155-257). Data expressed as mean value (95% confidence interval, C.I.) for x1000 cells/mm3. CAL also improved overall clinical condition and reduced by 36 % the duration of signs and symptoms of DF: 6.7-11.3 days, versus 11.5-16.6 days (95 % C.I., p<0.05) when compared with CTL patients. The possible mechanism of calcium attenuated thrombocytopenia and clinical improvement is discussed.