BACKGROUND: Dengue is endemic in Puerto Rico and causes periodic outbreaks involving thousands of persons. Seroprevalence studies among blood donors can provide useful data on the immune status of ...the adult population. The objective of this study was to determine the prevalence of anti‐dengue immunoglobulin (Ig)G antibodies in a random sample of blood donors to the American Red Cross (ARC) in Puerto Rico.
STUDY DESIGN AND METHODS: Three‐hundred randomly selected blood donations collected by the ARC from February 1 to March 31, 2006, were tested using an anti‐dengue IgG enzyme‐linked immunosorbent assay. One‐third of the positive specimens were randomly selected and tested by a microneutralization test (MNT) to determine the serotypes of previous dengue infections.
RESULTS: Most (84%) blood donors were male, and the mean age was 44.6 years (range, 18‐80 years). The prevalence (95% confidence interval) of anti‐dengue IgG antibodies was 92% (89%‐95%). Of the 92 specimens tested by the MNT, reactivity to all four dengue serotypes was observed and 96% were secondary infections. The predominant serotype with the highest neutralization titers, as identified by at least a fourfold higher titer compared to any other serotype tested, was identified in 32 specimens; the most common predominant serotypes identified by the MNT were DENV‐3 and DENV‐2 (63%). Recent infection with DENV‐1 was detected but, in 2005, routine surveillance did not detect any cases of this serotype.
CONCLUSION: Supplementary serologic testing of donated blood can potentially provide information on the silent circulation or introduction of dengue serotypes.
Dengue is a potentially fatal acute febrile illness caused by four mosquito-transmitted dengue viruses (DENV-1-4). Although dengue outbreaks regularly occur in many regions of the Pacific, little is ...known about dengue in the Republic of the Marshall Islands (RMI). To better understand dengue in RMI, we investigated an explosive outbreak that began in October 2011. Suspected cases were reported to the Ministry of Health, serum specimens were tested with a dengue rapid diagnostic test (RDT), and confirmatory testing was performed using RT-PCR and IgM ELISA. Laboratory-positive cases were defined by detection of DENV nonstructural protein 1 by RDT, DENV nucleic acid by RT-PCR, or anti-DENV IgM antibody by RDT or ELISA. Secondary infection was defined by detection of anti-DENV IgG antibody by ELISA in a laboratory-positive acute specimen. During the four months of the outbreak, 1,603 suspected dengue cases (3% of the RMI population) were reported. Of 867 (54%) laboratory-positive cases, 209 (24%) had dengue with warning signs, six (0.7%) had severe dengue, and none died. Dengue incidence was highest in residents of Majuro and individuals aged 10-29 years, and ∼95% of dengue cases were experiencing secondary infection. Only DENV-4 was detected by RT-PCR, which phylogenetic analysis demonstrated was most closely related to a virus previously identified in Southeast Asia. Cases of vertical DENV transmission, and DENV/Salmonella Typhi and DENV/Mycobacterium leprae co-infection were identified. Entomological surveys implicated water storage containers and discarded tires as the most important development sites for Aedes aegypti and Ae. albopictus, respectively. Although this is the first documented dengue outbreak in RMI, the age groups of cases and high prevalence of secondary infection demonstrate prior DENV circulation. Dengue surveillance should continue to be strengthened in RMI and throughout the Pacific to identify and rapidly respond to future outbreaks.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Dengue infection can be challenging to diagnose early in the course of infection before severe manifestations develop, but early diagnosis can improve patient outcomes and promote timely public ...health interventions. We developed age-based predictive models generated from 2 years of data from an enhanced dengue surveillance system in Puerto Rico. These models were internally validated and were able to differentiate dengue infection from other acute febrile illnesses with moderate accuracy. The accuracy of the models was greater than either the current World Health Organization case definition for dengue fever or a proposed modification to this definition, while requiring the collection of fewer data. In young children, thrombocytopenia and the absence of cough were associated with dengue infection; for adults, rash, leucopenia, and the absence of sore throat were associated with dengue infection; in all age groups, retro-orbital pain was associated with dengue infection.
As increasing numbers of dengue vaccines and therapeutics are in clinical development, standardized consensus clinical endpoint definitions are urgently needed to assess the efficacy of different ...interventions with respect to disease severity. We aimed to convene dengue experts representing various sectors and dengue endemic areas to review the literature and propose clinical endpoint definitions for moderate and severe disease based on the framework provided by the WHO 2009 classification.
The endpoints were first proposed and discussed in a structured expert consultation. After that, the Delphi method was carried out to assess the usefulness, validity and feasibility of the standardized clinical disease endpoints for interventional dengue research.
Most respondents (> 80%) agreed there is a need for both standardized clinical endpoints and operationalization of severe endpoints. Most respondents (67%) felt there is utility for moderate severity endpoints, but cited challenges in their development. Hospitalization as a moderate endpoint of disease severity or measure of public health impact was deemed to be useful by only 47% of respondents, but 89% felt it could bring about supplemental information if carefully contextualized according to data collection setting. Over half of the respondents favored alignment of the standard endpoints with the WHO guidelines (58%), but cautioned that the endpoints could have ramifications for public health practice. In terms of data granularity of the endpoints, there was a slight preference for a categorical vs numeric system (e.g. 1-10) (47% vs 34%), and 74% of respondents suggested validating the endpoints using large prospective data sets.
The structured consensus-building process was successful taking into account the history of the debate around potential endpoints for severe dengue. There is clear support for the development of standardized endpoints for interventional clinical research and the need for subsequent validation with prospective data sets. Challenges include the complexity of developing moderate disease research endpoints for dengue.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
BACKGROUND: Dengue virus (DENV) nucleic acid amplification testing of blood donations during epidemics in endemic locations, including Puerto Rico, has suggested possible sizable transfusion ...transmission risk. Estimates of the long‐term prevalence of DENV viremic donations will help evaluate the potential magnitude of this risk in Puerto Rico.
STUDY DESIGN AND METHODS: Estimates of the prevalence of DENV viremia in the Puerto Rican population at large from 1995 through 2010 were derived from dengue case reports and their onset dates obtained from islandwide surveillance, estimates of case underreporting, and extant data on the duration of DENV viremia and the unapparent‐to‐apparent dengue infection ratio. Under the assumptions that viremia prevalence in blood donors was similar to that of the population at large and that symptomatic persons do not donate, statistical resampling methods were used to estimate the prevalence of dengue viremia in blood donations.
RESULTS: Over the 16‐year period, the maximum and mean daily prevalences of dengue viremia (per 10,000) in blood donations in Puerto Rico were estimated at 45.0 (95% confidence interval CI, 36.5‐55.4) and 7.0 (95% CI, 3.9‐10.1), respectively. Prevalence varied considerably by season and year.
CONCLUSION: These data suggest a substantial prevalence of DENV viremia in Puerto Rican blood donations, particularly during outbreaks.
Research about neonatal outcomes among late preterm infants (34 weeks through 36 6/7 weeks of gestation) is limited. Understanding which late preterm infants are at risk for neonatal morbidity or ...mortality is necessary to improve health outcomes and reduce hospital costs. We conducted a population-based cohort study of “healthy,” singleton late preterm infants vaginally delivered in Massachusetts hospitals to Massachusetts residents between 1998 and 2002. We compared the incidence of neonatal morbidity (postdelivery inpatient readmissions, observational stays, or mortality) between “healthy,” late preterm infants with and without infant, obstetric, and sociodemographic factors by calculating risk ratios adjusted for confounding. Of the 9552 late preterm, “healthy” infants, 4.8% had an inpatient readmission and 1.3% had an observational stay. Infants with neonatal morbidity were more likely to be firstborn, be breastfed at discharge, have labor and delivery complications, be a recipient of a public payer source at delivery, or have an Asian/Pacific Islander mother. Non-Hispanic blacks had a decreased risk for neonatal morbidity compared to other racial/ethnic groups. Knowledge of risk factors for neonatal morbidity among “healthy” late preterm infants can be used to identify infants needing closer monitoring and earlier follow-up after hospital discharge.
Dengue often presents with non-specific clinical signs, and given the current paucity of accurate, rapid diagnostic laboratory tests, identifying easily obtainable bedside markers of dengue remains a ...priority. Previous studies in febrile Asian children have suggested that the combination of a positive tourniquet test (TT) and leucopenia can distinguish dengue from other febrile illnesses, but little data exists on the usefulness of these tests in adults or in the Americas. We evaluated the diagnostic accuracy of the TT and leucopenia (white blood cell count <5000/mm(3)) in identifying dengue as part of an acute febrile illness (AFI) surveillance study conducted in the Emergency Department of Saint Luke's Hospital in Ponce, Puerto Rico. From September to December 2009, 284 patients presenting to the ED with fever for 2-7 days and no identified source were enrolled. Participants were tested for influenza, dengue, leptospirosis and enteroviruses. Thirty-three (12%) patients were confirmed as having dengue; 2 had dengue co-infection with influenza and leptospirosis, respectively. An infectious etiology was determined for 141 others (136 influenza, 3 enterovirus, 2 urinary tract infections), and 110 patients had no infectious etiology identified. Fifty-two percent of laboratory-positive dengue cases had a positive TT versus 18% of patients without dengue (P<0.001), 87% of dengue cases compared to 28% of non-dengue cases had leucopenia (P<0.001). The presence of either a positive TT or leucopenia correctly identified 94% of dengue patients. The specificity and positive predictive values of these tests was significantly higher in the subset of patients without pandemic influenza A H1N1, suggesting improved discriminatory performance of these tests in the absence of concurrent dengue and influenza outbreaks. However, even during simultaneous AFI outbreaks, the absence of leucopenia combined with a negative tourniquet test may be useful to rule out dengue.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
AbstractDengue, a mosquito-borne viral disease, is increasingly being identified as a cause of outbreaks in the United States. During July-December 2013, a total of three south Texas counties ...reported 53 laboratory-confirmed dengue cases; 26 were locally acquired, constituting the largest outbreak in Texas since 2005. Because dengue outbreaks are expected to continue in south Texas and early case identification and timely treatment can reduce mortality, we sought to determine clinicians' knowledge of dengue and its clinical management. A survey was sent to 2,375 south Texas clinicians; 217 (9%) completed the survey. Approximately half of participants demonstrated knowledge needed to identify dengue cases, including symptoms (56%), early indicators of shock (54%), or timing of thrombocytopenia (48%). Fewer than 20% correctly identified all prevention messages, severe dengue warning signs, or circumstances in which a dengue patient should return for care. Knowledge of clinical management was limited; few participants correctly identified scenarios when plasma leakage occurred (10%) or a crystalloid solution was indicated (7%); however, 45% correctly identified when a blood transfusion was indicated. Because of the ongoing threat of dengue, we recommend clinicians in south Texas receive dengue clinical management training.
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