Dengue in pregnancy

This was a retrospective study of patients with dengue infection in pregnancy from year 2000 till 2004. Data were analyzed by looking at the presentation, complications of patient and fetus, and pregnancy outcomes. There was a total of 16 cases with an increasing trend (0.12% in 2003 vs 0.25% in 2004). The mean age of patients was 30.19+/-6.85 years. Fifty percent of patients were multiparae and in their third trimester. The average gestation was 24.44 weeks with 7.5 days being the average duration of ward admission. Tourniquet test was positive in 62.5% of patients. Dengue serology IgM was positive in 50% whereas dengue serology IgG were positive in 68.8% of patients. There were three cases of maternal death. One patient presented as missed abortion. Preterm deliveries happened in 50.0% of the women. There were 4 premature babies, one in-utero fetal death, and two fetuses which suffered acute fetal distress. Three babies required intensive care. One unrelated fetal anomaly resulted in early neonatal death.     

Dengue

The four dengue viruses are transmitted in tropical countries that circle the globe. All can cause syndromes that are self-limited or severe. The common severe syndrome--dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS)--is characterised by sudden vascular permeability generated by cytokines released when T cells attack dengue-infected cells. Dengue 1 virus became prevalent in Hawaii where it was transmitted by Aedes albopictus, producing a classic virgin soil epidemic, with clinical disease seen largely in adults. In Cuba and Singapore, sequential dengue infections at long intervals produced unusually severe disease in adults. Evidence suggests that enhancing and cross-reactive neutralising antibodies regulate dengue epidemics and disease severity. Classic DHF/DSS arises during initial dengue infections in infants with low circulating amounts of maternal dengue antibodies, an observation that precludes an exclusive causal role for secondary T-cell responses. Here, I review and discuss data on clinical diagnosis and pathophysiology of vascular permeability and coagulopathy, parenteral treatment of DHF/DSS, and new laboratory tests.     

Dengue

PURPOSE OF REVIEW: Because efforts to control dengue are flagging, this review focuses on the mechanisms underlying severe disease and on treatment options, good and bad. RECENT FINDINGS: The year 2001 witnessed unprecedented global dengue epidemic activity in the American hemisphere, the Pacific islands and continental Asia. Early diagnosis of dengue is important but what is the value and appropriate use of the tourniquet test? A negative test does not rule out dengue infection, a positive test should be followed by close surveillance for early signs of dengue hemorrhagic fever. Low platelet counts do not predict clinically significant bleeding in dengue. It follows that platelet or blood transfusions should not be administered based upon platelet count alone. Dengue hemorrhagic fever or dengue shock syndrome cases frequently have compensated consumptive coagulopathy that seldom requires treatment. Bleeding is most likely caused by activated platelets resulting from damaged capillary endothelium. Dengue hemorrhagic fever and dengue shock syndrome can be safely treated with just normal saline. Colloids should be immediately given to children presenting with a pulse pressure at or below 10 mmHg. Human leukocyte antigen alleles correlate with both protection and susceptibility to dengue hemorrhagic fever and dengue shock syndrome; studies in Haiti suggest that blacks have a gene providing nearly complete protection against severe dengue illness. SUMMARY: The role that antibodies play in protecting and enhancing dengue infections has been largely ignored. Such studies require definitive knowledge of what cells are infected in human dengue and an understanding of all the early antibody-accessible steps of infection of these target cells.     

Risk of Dengue in Travelers: Implications for Dengue Vaccination

Purpose of Review

Dengue is found in tropics and subtropics that are considered to be popular travel destinations. We set out to review the burden of dengue on international travelers.

Recent Findings

GeoSentinel, a global network of travel medicine providers, has seen an increasing trend of dengue in returning travelers over the past decades. In Southeast Asia, annual proportionate morbidity increased from 50 dengue cases per 1000 ill-returned travelers in non-epidemic years to an average of 159 cases per 1000 travelers during epidemic years. Dengue is the leading cause of fever in returning travelers, having overtaken malaria for travelers to Southeast Asia. Most dengue seroconversion studies in travelers report an attack rate of around 5% depending on duration of travel and destination.

Summary

Dengue vaccination would be justified for travelers. The first licensed dengue vaccine CYD-TDV is only recommended in seropositive individuals. This review considers preventive measures including how best to use the first licensed dengue vaccine CYD-TDV.

     

Dengue seroepidemiology in Singapore

The resurgence of dengue in Singapore since 1986 had been associated with an adult predominance and a very low incidence in children. No study had been carried out to investigate this finding. Here we report a serological study of 1068 children aged 0 to 15 years. There is a significant rise in seroconversion in children aged 6 years and older coinciding with the start of formal schooling. This suggests that there may be a change in the location where dengue is acquired.     

Dengue myocarditis

We report a 13-year-old boy who developed bradycardia and hypotension a day after recovery from dengue hemorrhagic fever. His electrocardiogram, during the bradycardia, showed a junctional rhythm with a rate of 50 beats/minute. This is the first reported case of sinus node dysfunction following dengue infection.     

Dengue hemorrhagic fever in infants

A report of 19 cases of serologically-proven dengue hemorrhagic fever (DHF) in infants aged 3-12 months who were admitted to the Department of Pediatrics, Chon Buri Regional Hospital, Thailand, during 1995 to 1998. Subjects were 8 males and 11 females, with the peak age of 8 months. Four cases (21%) had DHF and other common co-infections ie pneumonia (2 cases), Staphylococcus aureus sepsis (1 case) and Haemophilus influenzae meningitis (1 case). The clinical manifestations of the 15 DHF cases were high fever (100%), coryza (93.3%), hepatomegaly (80%), drowsiness (53.3 %), and vomiting (46.7%); rash was observed in only 27%; one-fifth developed febrile convulsions. Sites of bleeding were the skin (petechiae) 58%, gastrointestinal system (melena) 16%, and mucous membrane (epistaxis) 5%; thrombocytopenia and increased hematocrit (> or =20%) were noted in 95% and 84% respectively. The majority of the patients (18 cases, 95%) had primary infection; only one (5%) had secondary infection. The clinical severity of the DHF was Grade I, II, and III (dengue shock syndrome) in 21%, 47% and 32% of cases respectively. After appropriate and effective management, all the infants recovered fully.     

Dengue infections in HIV patients

A retrospective review of hospital admission records was conducted on patients who were admitted to the Communicable Disease Center (CDC)/Tan Tock Seng Hospital, Singapore from 1 January 2004 to 31 December 2005. There were 5 HIV patients who were admitted with dengue infection during the study period. Their symptoms were generally mild and recovery was uneventful. None of the patients developed dengue hemorrhagic fever or dengue shock syndrome. The symptoms and signs of dengue infection in HIV patients are nonspecific. It is important for healthcare workers to maintain a high index of suspicion in order to make the diagnosis. Interactions between pathogenesis pathways or with antiviral treatments may have contributed to the apparently less severe dengue infections in HIV patients. This observation needs to be explored further.     

东南亚国家和地区登革热的流行简况

登革热与登革出血热是蚊媒传播疾病，通过埃及伊蚊和白纹伊蚊传播。自１７７９年在印度尼西亚首都雅加达首次流行以来，世界各地陆续有此病的暴发流行，每次患病人数均超过百万。流行区主要分布于热带、亚热带地区，尤以东南亚为重。第二次世界大战后，全球的登革热在东南...