Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DENGUE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24Linked to original sources

Comparison of a dipstick dot-ELISA with commercial assays for anti-dengue virus IgM antibodies.

Dengue virus infections have undergone dramatic expansion in range, affecting several tropical and subtropical regions of the world. Dengue virus causes life-threatening complications characterized by dengue hemorrhagic fever and dengue shock syndrome. No standard validated test systems are available for serological diagnosis of dengue virus infection. This creates problems in the diagnosis and proper management of patients. Evaluation of a Defense Research and Development Establishment (DRDE) dengue virus dipstick dot-ELISA test, developed in house, vis-à-vis commercially available immunodiagnostic kits was carried out for detection of IgM antibodies. The DRDE dengue dipstick dot-ELISA was performed on the basis of the dot-ELISA principle. Commercial tests, namely, the Panbio Dengue IgM Capture ELISA system (Panbio, Sinnamon Park, Australia) and Pathozyme Dengue M (Omega Diagnostics, Alva, UK), were performed according to the manufacturers' protocols. Ninety-one serum samples collected from the states of Kerala and Delhi, India during August and November of 2004 were used in the present study. The overall agreement among all three tests was found to be only 72.16% for IgM antibodies. Correlations between the DRDE dipstick dot-ELISA and the Panbio kit, between the DRDE dipstick dot-ELISA and the Pathozyme Dengue M kit, and between the Panbio kit and the Pathozyme Dengue M kit were found to be 96, 93, and 94%, respectively. Although the Panbio kit is widely used in various laboratories in India, the DRDE dipstick dot-ELISA promises to be a useful kit because of its field applicability and comparable sensitivity.

Animals↗

Determinants of dengue 2 infection among residents of Charters Towers, Queensland, Australia.

Dengue fever is caused by one of the four serotypes of the dengue virus and is transmitted by the urban mosquito Aedes aegypti. In 1993, the city of Charters Towers in the tropical north of Australia experienced an epidemic caused by the dengue 2 virus. A cross-sectional sample of 1,000 people was assessed for determinants of recent symptomatic dengue infection. After exclusion of people with prior exposure to dengue 2, a study group of 797 persons, including 196 patients with recent infection, were evaluated. Stepwise logistic regression analysis identified four determinants of infection: the presence of a case of dengue fever within two residential blocks (odds ratio (OR) = 3.61, 95% confidence interval (CI) 2.56-5.10), house screening (OR = 0.60, 95% CI 0.40-0.89), the presence of a water tank within two residential blocks (OR = 1.51, 95% CI 1.02-2.22), and the use of knockdown insecticide (OR = 1.75, 95% CI 1.22-2.51). Classification and Regression Tree analysis identified a group of 152 individuals in whom the prevalence of dengue infection was 50%. These people lived within two blocks of a suspected dengue fever case, did not have house screening, and used knockdown sprays. If dengue had not occurred within two residential blocks, there were no additional factors that significantly influenced the prevalence of dengue fever. Control of dengue epidemics should involve attempts to geographically contain the spread of infection, use of house screening, and the removal of mosquito breeding sites such as water tanks.

Adult↗

Evaluation of an enzyme immunoassay for detection of dengue virus NS1 antigen in human serum.

We evaluated a one-step sandwich-format microplate enzyme immunoassay for detecting dengue virus NS1 antigen (Ag) in human serum by use of Platelia Dengue NS1 Ag kits (Bio-Rad Laboratories, Marnes La Coquette, France). We collected 299 serum samples from patients with dengue disease and 50 serum samples from patients not infected with dengue virus. For the 239 serum samples from patients with acute infections testing positive by reverse transcription-PCR and/or virus isolation for one of the four dengue virus serotypes, the sensitivity of the Platelia Dengue NS1 Ag kit was 88.7% (95% confidence interval, 84.0% to 92.4%). None of the serum samples from patients not infected with dengue virus tested positive with the Platelia Dengue NS1 Ag kit. A diagnostic strategy combining the Platelia Dengue NS1 Ag test for acute-phase sera and immunoglobulin M capture enzyme-linked immunosorbent assay for early-convalescent-phase sera increased sensitivity only from 88.7% to 91.9%. Thus, NS1 antigen detection with the Platelia Dengue NS1 Ag kit could be used for first-line testing for acute dengue virus infection in clinical diagnostic laboratories.

Adolescent↗

Cost-effective real-time reverse transcriptase PCR (RT-PCR) to screen for Dengue virus followed by rapid single-tube multiplex RT-PCR for serotyping of the virus.

Virus detection methodology provides detection of dengue virus in the early phase of the disease. PCR, targeting cDNA derived from viral RNA, has been used as a laboratory-based molecular tool for the detection of Dengue virus. We report the development and use of three real-time one-step reverse transcriptase PCR (RT-PCR) assays to detect dengue cases and serotype the virus involved. The first RT-PCR assay uses SYBR green I as the reporting dye for the purpose of cost-effective screening for dengue virus. The detection limit of the SYBR green I assay was 10 PFU/ml (0.01 equivalent PFU per assay) for all four dengue virus serotypes. The second RT-PCR assay is a duplex fluorogenic probe-based real-time RT-PCR for serotyping clinical samples for dengue viruses. The detection threshold of the probe-based RT-PCR format was 0.1 PFU for serotypes Dengue-1 and Dengue-2, 1 PFU for serotype Dengue-3, and 0.01 PFU for serotype Dengue-4. The third is a fourplex assay that detects any of the four serotypes in a single closed tube with comparable sensitivity. Validation of the assays with local clinical samples collected from 2004 to 2006 revealed that there was an 88% positive correlation between virus isolation and RT-PCR with regard to dengue virus detection and a 100% correlation with seroconversion in subsequent samples. The serotyping results derived from duplex and fourplex assays agree fully with each other and with that derived from immunofluorescence assays.

Aedes↗

Rapid diagnosis of dengue viremia by reverse transcriptase-polymerase chain reaction using 3'-noncoding region universal primers.

A reverse transcriptase-polymerase chain reaction (RT-PCR) method was developed as a rapid diagnostic test of dengue viremia. To detect dengue viruses in serum or plasma specimens, a pair of universal primers was designed for use in the RT-PCR. Using these primers, the 3'-noncoding region of dengue virus types 1, 2, 3, and 4 could be amplified, but not those of other flaviviruses, such as West Nile virus, Japanese encephalitis virus, and yellow fever virus, or the alphavirus Sindbis virus. The sensitivity of the RT-PCR assay was similar to that of a quantitative fluorescent focus assay of dengue viruses in cell culture. Combining a silica method for RNA isolation and RT-PCR dengue virus could be detected in a 6-hr assay. In a preliminary study using this method, we detected dengue virus in 38 of 39 plasma specimens from which dengue virus had been isolated by mosquito inoculation. We then applied this method for detecting dengue viremia to 117 plasma samples from 62 children with acute febrile illnesses in a dengue-endemic area. We detected dengue viremia in 19 of 20 samples obtained on the day of presentation, which had been confirmed as acute dengue infection by mosquito inoculation and antibody responses. The overall sensitivity of this method was 91.4% (32 of 35; 95% confidence interval [CI] = 82.2-100%). The results from testing plasma samples from febrile nondengue patients showed a specificity of 95.4% (42 of 44; 95% CI = 89.3-100%).

Acute Disease↗

Inflammatory mediators in dengue virus infection in children: interleukin-6 and its relation to C-reactive protein and secretory phospholipase A2.

To assess the potential role of interleukin-6 (IL-6) in the pathogenesis of dengue virus infection, levels of this cytokine were measured in children with dengue virus infection on admission to the hospital. As presumed surrogate markers of IL-6, C-reactive protein (CRP) and secretory phospholipase A2 (sPLA2) were measured. Three groups were studied: 33 apparently healthy children as negative controls, 11 children with bacterial infections as positive controls, and 186 children with serologically documented dengue virus infection. One-hundred and fifteen patients had dengue fever (DF) and 71 had dengue hemorrhagic fever (DHF). Compared with healthy controls, dengue shock syndrome (DSS) patients had significantly higher levels of IL-6 on admission (P < 0.05), comparable with those in positive controls. Dengue patients with shock had significantly higher levels of IL-6 than normotensive patients (P < 0.001) and higher levels of IL-6 were associated with a higher incidence of ascites. C-reactive protein concentrations in dengue patients and in healthy children were not different, but lower than in children with bacterial infections (P = 0.008). Secretory phospholipase A2 levels were higher in dengue patients than in apparently healthy children (P < or = 0.05) and similar to those in children with bacterial infection. Dengue shock syndrome patients had significantly higher sPLA2 concentrations than normotensive patients (P = 0.02). These data indicate that IL-6 and sPLA2 may have a pathogenetic role only in the most severe forms of dengue virus infection.

Adolescent↗

High-level expression of recombinant dengue viral NS-1 protein and its potential use as a diagnostic antigen.

The prevalence of NS1 Ab response in patients with dengue viral infection and the potential of using recombinant NS1 protein as a diagnostic antigen for dengue viral infection were investigated. In this study, the full-length and C-terminal half of NS1 proteins (rNS1, rNS1-C) were highly expressed (10-30 mg/l) and further purified and refolded. The good antigenicity of the full-length rNS1 protein was confirmed by interaction with 19 dengue NS1-specific monoclonal antibodies (MAbs) in ELISA; however, the antigenicity of rNS1-C was relatively lower. The full-length rNS1 antigen also differentiated reliably between sera from dengue virus-infected patients and sera from normal controls. When rNS1 was used as an antigen to detect human anti-NS1 IgM and IgG Ab, the anti-NS1 Ab response was found in 15 of 17 patients (88%) with primary dengue infection and all 16 patients (100%) with secondary dengue infection. These results indicated that using the full-length rNS1 whose antigenicity is restored as ELISA antigen, a high anti-NS1 antibody prevalence could be detected in patients with either primary or secondary dengue infection. This finding suggested that the anti-NS1 antibody appeared not only in secondary and severe dengue virus infection and might not correlate the pathogenesis of dengue hemorrhagic fever. The study also verified that our purified rNS1 protein showed similar immunological properties as native dengue viral proteins. Genetic engineering production of recombinant NS1 antigen could provide a safe and valuable resource for dengue virus serodiagnosis.

Animals↗

Epidemiological features of dengue and chikungunya infections in Burma.

A serological survey for antibody to dengue and chikungunya was carried out in all 14 divisions and states and 2 border towns in Burma during 1973-74. Dengue HI antibody prevalence rate of less than 10% was observed in Arakan and Shan States, 10 to 30% in the Irrawaddy, Pegu, Mandalay Divisions and Kachin, Mon and Karen States, 31 to 60% in Sagaing Division, and over 60% in Rangoon, Magwe and Tenasserim Divisions. Similarly, chikungunya HI antibody prevalence rate of less than 10% was observed in Arakan State, 10 to 30% in the Irrawaddy, Pegu, Mandalay and Sagaing Divisions and Kachin State, 31 to 60% in Rangoon Division and Mon State. Both dengue and chikungunya antibodies were detected where Aedes aegypti mosquitoes were prevalent but the antibody prevalent rates were not directly proportional to the premises index. No HI antibody to dengue nor chikungunya was detected in Aedes aegypti free hilly areas, Chin and Kayah States, but was detected in the Shan State, Dengue and chikungunya infections were observed both in rural and urban populations. Dengue and chikungunya infections affected all socioeconomic classes in Rangoon equally but in Mandalay high socioeconomic class was nearly 3 times less affected than lower socioeconomic class. The infrequencies of dengue and chikungunya infections were observed to be 2 to 3 times higher in residents of Rangoon City than those of other towns. In Rangoon the antibody prevalence rates to dengue increased progressively with age while in other towns no appreciable increase in rates with age was observed. Both sexes were equally affected. This study provides strong circumstantial evidence that dengue and chikungunya viruses are highly and widely distributed throughout Burma, and that new outbreaks of haemorrhagic fever could occur in previously free areas following introduction of dengue viruses into populations previously exposed to one type of dengue.

Aedes↗

Serological and entomological investigations of an outbreak of dengue fever in certain rural areas of Kanyakumari district, Tamil Nadu.

BACKGROUND AND OBJECTIVES: During the first week of July 2003, suspected cases of dengue fever were reported from three villages in Kanyakumari district in Tamil Nadu. Since the fever outbreak occurred for the first time in these villages, serological, virological and entomological investigations were carried out to confirm the aetiology of outbreak. METHODS: A total of 76 plasma samples were collected from suspected cases of dengue fever and screened for the presence of IgM antibodies by Pan Bio ELISA kit. Toxo-IFA system was used for the isolation of dengue virus from the plasma samples. Vector survey employing ovitraps and adult landing collection were carried out in the study villages. Pooled samples of Aedes mosquito were screened for dengue virus antigen by an in-house antigen capture ELISA test employing dengue virus specific monoclonal antibodies. RESULTS: Of the 76 samples tested, 15 (20%) were found positive for dengue virus specific IgM antibodies. Dengue virus serotype-3 was detected from a plasma sample by Toxo-IFA test using virus specific monoclonal antibodies. Entomological survey revealed the abundance of Aedes albopictus (Skuse) mosquitoes in the study area. One pool consisting of 12 Ae. albopictus males were found positive for dengue virus infection. INTERPRETATION AND CONCLUSION: Based on the IgM antibody capture ELISA results, it was evident that the current infection was caused by dengue virus in the affected areas. All the age groups were affected during this outbreak. Detection of dengue virus serotype-3 in plasma samples further confirmed the aetiology of this outbreak. The high prevalence of the mosquito vector Ae. albopictus (Skuse) was observed. Detection of dengue virus antigen in the male mosquitoes confirms that the virus is maintained in wild populations of Ae. albopictus in these areas.

Adolescent↗

[Dengue in Nicaragua, 1994: reintroduction of serotype 3 in the Americas].

The principal aim of this work was to report the reintroduction of dengue virus serotype 3 in the Americas after an absence of 17 years. In addition, it describes the most common symptoms associated with classical dengue and hemorrhagic dengue and presents data on the distribution of the epidemic in the various comprehensive local health care systems of Nicaragua. The study group consisted of 39 patients hospitalized in Managua and León for dengue with hemorrhagic manifestations and hemorrhagic dengue. Of these patients, 34 were classified as probable or confirmed cases of dengue. The most frequent symptoms were fever, headache, vomiting, and muscle and joint pains. The tourniquet test was positive and thrombocytopenia was confirmed in 56% and 44% of the patients, respectively. Epistaxis (67%) was the most common hemorrhagic sign. Of the 356 serum samples received through the dengue surveillance systems in October 1994, IgM antibodies were detected in 43%. The virus was isolated from 5 of 24 samples tested (serotype 3 from 3 and serotype 1 from 2). The reintroduction of serotype 3 of dengue into the Region was demonstrated, along with its ability to produce epidemics of hemorrhagic dengue. The countries are warned that if they do not quickly take the measures described in the guidelines for the prevention and control of dengue and dengue hemorrhagic fever, new epidemics may occur in the Americas, given the large number of persons susceptible to this serotype and the high density of the mosquito vector in most of the countries of the Region.

Adolescent↗

Differential enhancement of dengue virus immune complex infectivity mediated by signaling-competent and signaling-incompetent human Fcgamma RIA (CD64) or FcgammaRIIA (CD32).

Fcgamma receptor (FcgammaR)-mediated entry of infectious dengue virus immune complexes into monocytes/macrophages is hypothesized to be a key event in the pathogenesis of complicated dengue fever. FcgammaRIA (CD64) and FcgammaRIIA (CD32), which predominate on the surface of such dengue virus-permissive cells, were compared for their influence on the infectivity of dengue 2 virus immune complexes formed with human dengue virus antibodies. A signaling immunoreceptor tyrosine-based activation motif (ITAM) incorporated into the accessory gamma-chain subunit that associates with FcgammaRIA and constitutively in FcgammaRIIA is required for phagocytosis mediated by these receptors. To determine whether FcgammaRIA and FcgammaRIIA activation functions are also required for internalization of infectious dengue virus immune complexes, we generated native and signaling-incompetent versions of each receptor by site-directed mutagenesis of ITAM tyrosine residues. Plasmids designed to express these receptors were transfected into COS-7 cells, and dengue virus replication was measured by plaque assay and flow cytometry. We found that both receptors mediated enhanced dengue virus immune complex infectivity but that FcgammaRIIA appeared to do so far more effectively. Abrogation of FcgammaRIA signaling competency, either by expression without gamma-chain or by coexpression with gamma-chain mutants, was associated with significant impairment of phagocytosis and of dengue virus immune complex infectivity. Abrogation of FcgammaRIIA signaling competency was also associated with equally impaired phagocytosis but had no discernible effect on dengue virus immune complex infectivity. These findings point to fundamental differences between FcgammaRIA and FcgammaRIIA with respect to their immune-enhancing capabilities and suggest that different mechanisms of dengue virus immune complex internalization may operate between these FcgammaRs.

Animals↗

Selection for virulent dengue viruses occurs in humans and mosquitoes.

Dengue is the most common mosquito-borne viral disease in humans. The spread of both mosquito vectors and viruses has led to the resurgence of epidemic dengue fever (a self-limited flu-like syndrome) and the emergence of dengue hemorrhagic fever (severe dengue with bleeding abnormalities) in urban centers of the tropics. There are no animal or laboratory models of dengue disease; indirect evidence suggests that dengue viruses differ in virulence, including their pathogenicities for humans and epidemic potential. We developed two assay systems (using human dendritic cells and Aedes aegypti mosquitoes) for measuring differences in virus replication that correlate with the potential to cause hemorrhagic dengue and increased virus transmission. Infection and growth experiments showed that dengue serotype 2 viruses causing dengue hemorrhagic fever epidemics (Southeast Asian genotype) can outcompete viruses that cause dengue fever only (American genotype). This fact implies that Southeast Asian genotype viruses will continue to displace other viruses, causing more hemorrhagic dengue epidemics.

Aedes↗

Importation of dengue by soldiers returning from East Timor to north Queensland, Australia.

BACKGROUND: Soldiers based in Townsville, Australia, returned from East Timor following peacekeeping operations during the wet season of 1999 to 2000. This represented the potential to import dengue virus into north Queensland, a dengue receptive area of Australia. This article seeks to outline the measures taken by the Australian Defence Force (ADF) to prevent local transmission and to present the outcomes. METHODS: Soldiers returning to north Queensland were provided with education on dengue fever and in the fortnight before return, their living areas were subjected to intensive vector control measures, in order to reduce the risk of acquisition of dengue. They were further encouraged to present early with any febrile illness following their return to Townsville. Provisionally diagnosed dengue cases were notified to the state public health authorities immediately and cases were isolated until suitable vector control programs were implemented or the potentially viremic period exceeded. Serologic and virologic investigations were undertaken to identify the passage and probable serotype or confirm the presence and serotype of dengue virus. RESULTS: Nine serologically confirmed cases of dengue were identified as viremic in north Queensland. Six cases were identified as arising from dengue serotype 2, two were from serotype 3, and one case was ill defined. No dengue cases have been reported in the local population 4 months following these ADF cases. CONCLUSIONS: Local outbreaks of dengue fever have occurred in north Queensland following the importation of dengue virus in returned travelers. The successful prevention of local transmission in these circumstances was contributed to by early notification of cases and prevention of transmission through isolation of cases and collaboration between ADF and state and local public health authorities in vector control. The management of potentially viremic returning service personnel represents a future challenge for the ADF.

Dengue↗

Transmission of dengue 1 and 2 viruses in Greece in 1928.

In August-September 1928 appoximately 650,000 residents of Athens and Piraeus contracted dengue fever, and 1,061 died. We were interested in the etiology of this severe epidemic in which many cases resembled dengue hemorrhagic fever or the dengue shock syndrome, and have attempted a retrospective seroepidemiological study. Serum specimens were obtained from 111 residents of Athens or Piraeus who were born in 1927 or 1928, and were studied by plaque reduction neutralization test for antibodies to dengue 1-4 viruses. Of 75 persons born in 1928, 20 (27%) had monospecific dengue 1, 10 (13%) had monospecific dengue 2, and 1 (1%) had dengue 1 and 2 neutralizing antibodies. When prevalence of neutralizing antibody was analyzed by month of birth in 42 individuals, evidence of both dengue 1 and 2 infections was found in persons born in January-July, but only dengue 2 antibody was detected in those who were born after July. This study dates dengue 1 and dengue 2 transmission to 1928, allowing for the possibility that sequential infections with these viruses could have played a pathogenetic role in the outbreak.

Antibodies, Viral↗

Replication of dengue-2 virus in cultured human lymphoblastoid cells and subpopulations of human peripheral leukocytes.

We studied the susceptibility of four human lymphoblastoid cell lines (HCL) and of subpopulations of circulating peripheral human leukocytes to dengue-2 virus infection. HCL with B cell characteristics (Raji, Wil 2WT, 8866), B-type peripheral lymphocytes, and macrophages were productively infected by dengue-2 virus. In contrast, an HCL with T cell characteristics (MOLT-4), T type peripheral lymphocytes, and polymorphonuclear (PMN) cells did not become infected and replicate dengue-2 virus. PMN cells did not adsorb dengue-2 virus, suggesting lack of viral receptors. However, T-type cultured lymphoblasts and T-type peripheral lymphocytes adsorbed dengue-2 virus, suggesting that the block in viral replication involves some stage of infection occurring after adsorption. Permissiveness of B-type HCL to dengue-2 virus infection was dependent on the virus seed used but the virus titers obtained among the susceptible HCL varied. HCL infected persistently with dengue-2 virus have been established. Human peripheral lymphocytes inoculated after cultivation for 3 days in complete medium alone or complete medium supplemented with mitogens replicated dengue-2 virus. In contrast, unstimulated peripheral lymphocytes inoculated immediately after isolation adsorbed dengue-2 but did not support its replication. Mitogen-treated and untreated macrophages replicated dengue-2 virus equally well. The efficiency of dengue-2 virus replication by macrophages was higher than that of peripheral lymphocytes but lower than that of HCL.

B-Lymphocytes↗

Primary dengue infection: what are the clinical distinctions from secondary infection?

To determine the magnitude of the problem posed by primary dengue infection in children and the distinctive clinical clues that may differ from those with secondary infection, 996 children serologically diagnosed with dengue infection and admitted to the Department of Pediatrics, Chulalongkorn Hospital, Bangkok, Thailand between 1988 and 1995 were retrospectively reviewed. One hundred and thirty-nine cases (14.0%) were serologically proved to be primary dengue infection. Of these, 72 were males and 67 were females, with a mean age of 4.8 years. Common manifestations by order of frequency included fever (97.8%), hepatomegaly (71.9%), vomiting (59.0%), decreased appetite (55.4%), coryza (52.5%), drowsiness (39.6%), diarrhea (34.5%), rash (33.8%), abdominal pain (23.0%) and seizure (15.8%). The mean duration of fever before admission was 4.6 days. Common sites of bleeding were skin (41.7%), mucous membrane (14.4%) and the gastrointestinal tract (12.2%). Clinical diagnosis was categorized into dengue fever (22.3%), dengue hemorrhagic fever (60.4%) and dengue shock syndrome (17.3%). Three patients (2.2%) died. Compared with the children with secondary dengue infection (n=139), children with primary dengue infections tended to be younger, presented more commonly with coryza, diarrhea, rash and seizure; and less commonly with vomiting, headache and abdominal pain (p < 0.05). The maximal hematocrit level, the mean difference between maximal and minimal hematocrit values and the maximal percentage of neutrophils were significantly lower in the study group, whereas the maximal percentage of lymphocytes was significantly higher. Dengue fever was more common and dengue shock syndrome was less common in the study group (p < 0.05). This study has emphasized that primary dengue infection is not uncommon and is less severe than secondary infection. Clinical presentations and laboratory findings are somewhat different between the two conditions.

Adolescent↗

Vertical transmission of dengue infection in Thai infants: two case reports.

Dengue infection is hyperendemic in tropical countries especially in Thailand. Most dengue infections occur during childhood but some adults may remain susceptible to infection. About 30 per cent of dengue infection are reported in patients > 15 years old. Some pregnant women may also be susceptible to dengue and if they experience dengue infection, they can transmit the dengue viruses to their babies. The authors report two babies who developed mild dengue illness, dengue hemorrhagic fever (DHF) grade II, beginning on their 6th day of life. Both of them had low grade fever, hepatomegaly and generalized petechial rash. The first baby had Hct ranging from 46 to 40 per cent with minimal right pleural effusion. The lowest platelet count was 19,000 cells/mm3. His mother had dengue shock syndrome with masssive post partum bleeding. The second baby had dengue 2 infection while his mother had dengue fever. His Hct had also risen from 52 per cent to 61 per cent with right pleural effusion. His lowest platelet count was 7,000 cells/mm3. Both mothers and their babies had a complete recovery although the first baby had prolonged thrombocytopenia for two months.

Adult↗

Use of a geographic information system for defining spatial risk for dengue transmission in Bangladesh: role for Aedes albopictus in an urban outbreak.

We used conventional and spatial analytical tools to characterize patterns of transmission during a community-wide outbreak of dengue fever and dengue hemorrhagic fever in Dhaka, Bangladesh in 2000. A comprehensive household-level mosquito vector survey and interview was conducted to obtain data on mosquito species and breeding as well as illness consistent with dengue. Clusters of dengue illnesses and high-density vector populations were observed in a distinct sector of the city. Dengue clusters are less identifiable in areas further away from major hospitals, suggesting that proximity to hospitals determines whether cases of dengue are diagnosed. Focusing on those areas relatively close to hospitals, we found a spatial association between dengue clusters and vector populations. Households reporting a recent dengue illness were more likely to have Aedes albopictus larvae present in the home when compared with households not reporting cases. Households reporting a recent dengue illness were also more likely to have a neighbor with Ae. albopictus present in the home. In contrast, the presence of Aedes aegypti within the premises as well as the homes of neighbors (within 50 meters) was not associated with dengue illness. Given that the breeding habitats for Ae. albopictus are somewhat distinct from those of Ae. aegypti, the findings of this study have implications for control of dengue transmission in this urban setting where much of the focus has been on indoor mosquito breeding and transmission. Public health officials may find the disease-environment map useful for planning targeted interventions because it displays areas where transmission is most intense.

Aedes↗