RESUMO
Dengue is an emerging tropical disease infecting tens of millions of people annually. A febrile illness with potentially severe hemorrhagic manifestations, dengue is caused by mosquito-borne viruses (DENV-1 to -4) that are maintained in endemic transmission in large urban centers of the tropics with periodic epidemic cycles at 3- to 5-year intervals. Puerto Rico (PR), a major population center in the Caribbean, has experienced increasingly severe epidemics since multiple dengue serotypes were introduced beginning in the late 1970s. We document the phylodynamics of DENV-4 between 1981 and 1998, a period of dramatic ecological expansion during which evolutionary change also occurs. The timescale of viral evolution is sufficiently short that viral transmission dynamics can be elucidated from genetic diversity data. Specifically, by combining virus sequence data with confirmed case counts in PR over these two decades, we show that the pattern of cyclic epidemics is strongly correlated with coalescent estimates of effective population size that have been estimated from sampled virus sequences using Bayesian Markov Chain Monte Carlo methods. Thus, we show that the observed epidemiologic dynamics are correlated with similar fluctuations in diversity, including severe interepidemic reductions in genetic diversity compatible with population bottlenecks that may greatly impact DENV evolutionary dynamics. Mean effective population sizes based on genetic data appear to increase prior to isolation counts, suggesting a potential bias in the latter and justifying more active surveillance of DENV activity. Our analysis explicitly integrates epidemiologic and sequence data in a joint model that could be used to further explore transmission models of infectious disease.
Assuntos
Evolução Biológica , Vírus da Dengue/genética , Dengue/epidemiologia , Dengue/virologia , Surtos de Doenças , Animais , DNA Viral/análise , Dengue/transmissão , Vírus da Dengue/isolamento & purificação , Probabilidade , Porto Rico/epidemiologiaRESUMO
Yellow fever and dengue are old diseases, having caused major epidemics in centuries past. Both were effectively controlled in the mid 1900s, yellow fever in Francophone Africa by vaccination and yellow fever and dengue in the Americas by effective control of the principal urban vector of both viruses, Aedes aegypti. In the last 25 years of the 20th century, however, there was a resurgence of yellow fever in Africa, and of dengue worldwide. The factors responsible for this resurgence are discussed, as are current options for prevention and control.
Assuntos
Vírus da Dengue/crescimento & desenvolvimento , Dengue/epidemiologia , Febre Amarela/epidemiologia , Vírus da Febre Amarela/crescimento & desenvolvimento , Aedes/virologia , África Subsaariana/epidemiologia , Animais , Sudeste Asiático/epidemiologia , Dengue/prevenção & controle , Dengue/virologia , Humanos , Controle de Insetos/métodos , Insetos Vetores/virologia , América do Sul/epidemiologia , Febre Amarela/prevenção & controle , Febre Amarela/virologiaRESUMO
BACKGROUND: Dengue, a mosquito-transmitted viral disease, is a risk for visitors in tropical and subtropical areas. Several participants in a community-assistance program in Tortola, British Virgin Islands, in August, 1995, reported dengue-like symptoms either before or soon after leaving the island. METHODS: We conducted a retrospective cohort study to determine the extent of the outbreak, risk factors for illness, and the proportion of inapparent infections. Program participants were interviewed by telephone or mail, and asked to submit a serum sample for dengue diagnosis. A clinically-diagnosed case of dengue was defined as a person with fever and two or more of the following: headache, retro-orbital pain, myalgia, arthralgia, rash, or hemorrhagic manifestations. Serum specimens were tested for virus isolation, polymerase chain reaction (PCR), plaque-reduction neutralization (PRNT) or anti-dengue IgM and IgG antibody. RESULTS: Thirty-two (97%) of the 33 program participants responded; 21 of the 32 (66%) provided at least one serum sample for study. The median age was 17 years; 20 (62%) were women. Of 32 respondents, 22 (69%) met the clinical case definition for dengue: 15 of them (68%) had a positive IgM antibody response and 7 did not submit a serum sample. Dengue 1 virus (DEN-1) was identified by PCR in one case and all 11 positive PRNT results. No asymptomatic infections were identified. No respondent used effective mosquito repellent, and only 2 (6%) used bednets. CONCLUSIONS: A DEN-1 outbreak with a high attack rate (69%) occurred in a group of young short-term community aid workers. There were no asymptomatic infections documented. Participants' rare use of bednets or effective mosquito repellent highlights the importance of providing travelers to tropical areas with information about dengue fever and the recommended precautions to protect against infection.
Assuntos
Dengue/epidemiologia , Surtos de Doenças , Viagem , Adolescente , Anticorpos Antivirais/sangue , Dengue/diagnóstico , Vírus da Dengue/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Reação em Cadeia da Polimerase , Socorro em Desastres , Estudos Retrospectivos , Fatores de Risco , Índias Ocidentais/epidemiologiaRESUMO
Four serotypes of dengue viruses produce dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. They are the most important arbovirus infections of humans, in terms of both morbidity and mortality, constituting one of the most rapidly expanding and re-emerging infectious disease problems in Latin America. In less than 20 years, the region has transformed itself from hypoendemic to hyperendemic, while serotype circulation in most countries has gone from none or single to multiple. Changes in endemicity have coincided with the emergence and increasing incidence of the severer forms of dengue infection. This article reviews the clinical presentations of these diseases. Health care providers who see patients in or returning from areas of Latin America, the Caribbean, and other tropical areas must consider dengue in the differential diagnosis of patients presenting with compatible symptoms, and must be knowledgeable in the current management of this important disease.
Assuntos
Vírus da Dengue/fisiologia , Dengue , Dengue Grave , Aedes/virologia , Animais , Região do Caribe/epidemiologia , Dengue/diagnóstico , Dengue/epidemiologia , Dengue/terapia , Dengue/virologia , Vírus da Dengue/imunologia , Humanos , Insetos Vetores , América Latina/epidemiologia , Controle de Mosquitos , Dengue Grave/diagnóstico , Dengue Grave/epidemiologia , Dengue Grave/terapia , Dengue Grave/virologia , Vacinas ViraisAssuntos
Dengue/epidemiologia , Países em Desenvolvimento , Surtos de Doenças/prevenção & controle , Adolescente , Adulto , Distribuição por Idade , Animais , Sudeste Asiático/epidemiologia , Região do Caribe/epidemiologia , Criança , Dengue/diagnóstico , Dengue/economia , Dengue/terapia , Surtos de Doenças/história , Saúde Global , História do Século XVIII , História do Século XIX , História do Século XX , Humanos , Prevalência , Dengue Grave/diagnóstico , Dengue Grave/economia , Dengue Grave/epidemiologia , Dengue Grave/virologia , América do Sul/epidemiologia , Taxa de SobrevidaRESUMO
The co-circulation of all 4 dengue virus serotypes in the same community, common since the 1950s in Southeast Asia, has now become a frequent occurrence in many Caribbean Islands, Mexico, and Central and South America in the past 20 years. As a consequence, the frequency of concurrent infections would be expected to increase in these areas. To assess this, using state of the art technology, we screened viremic serum samples and mosquitoes inoculated with serum samples collected during epidemics involving multiple dengue virus serotypes in Indonesia, Mexico, and Puerto Rico for virus isolation. Of 292 samples tested, 16 (5.5%) were found to contain 2 or more dengue viruses by an indirect immunofluorescence test and/or the reverse transcriptase-polymerase chain reaction.
Assuntos
Vírus da Dengue/classificação , Surtos de Doenças , Dengue Grave/virologia , Animais , Anticorpos Monoclonais , Anticorpos Antivirais/sangue , Bioensaio , Células Cultivadas , Culicidae/virologia , Primers do DNA/química , Vírus da Dengue/genética , Vírus da Dengue/imunologia , Vírus da Dengue/patogenicidade , Eletroforese em Gel de Ágar , Técnica Direta de Fluorescência para Anticorpo , Humanos , Indonésia/epidemiologia , México/epidemiologia , Porto Rico/epidemiologia , RNA Viral/química , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sorotipagem , Dengue Grave/sangue , Dengue Grave/epidemiologiaRESUMO
This report describes the clinical, laboratory, and epidemiological findings on 27 cases of Mayaro virus (MV) disease, an emerging mosquito-borne viral illness that is endemic in rural areas of tropical South America. MV disease is a nonfatal, dengue-like illness characterized by fever, chills, headache, eye pain, generalized myalgia, arthralgia, diarrhea, vomiting, and rash of 3-5 days' duration. Severe joint pain is a prominent feature of this illness; the arthralgia sometimes persists for months and can be quite incapacitating. Cases of two visitors from the United States, who developed MV disease during visits to eastern Peru, are reported. MV disease and dengue are difficult to differentiate clinically.
Assuntos
Infecções por Alphavirus/diagnóstico , Alphavirus/isolamento & purificação , Adulto , Distribuição por Idade , Alphavirus/classificação , Alphavirus/genética , Alphavirus/imunologia , Infecções por Alphavirus/epidemiologia , Infecções por Alphavirus/virologia , Animais , Anticorpos Antivirais/sangue , Culicidae , DNA Viral/análise , Feminino , Humanos , Insetos Vetores , Pessoa de Meia-Idade , Peru/epidemiologia , Estações do Ano , Análise de Sequência de DNA , ZoonosesRESUMO
This study presents the disability-adjusted life years (DALYs), a non-monetary economic measure of impact, lost to dengue in Puerto Rico for the period 1984-1994. Data on the number of reported cases, cases with hemorrhagic manifestations, hospitalizations, and deaths were obtained from a surveillance system maintained at the Dengue Branch, Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention (San Juan, PR). The reported cases were divided into two age groups (0-15 years old and >15 years old), and then multiplied by predetermined factors (10 for 0-15 years; 27 for >15 years) to allow for age-related under-reporting of cases. Severity of dengue was modeled by classifying cases into three groups: dengue fever, dengue with severe manifestations, and hospitalized cases. Each group was assigned a different number of days lost because of dengue-related disability. Dengue caused an average of 658 DALYs per year per million population (SE = 114, range = 145-1,519). A multivariate sensitivity analysis, which simultaneously altered the values of six input variables, produced a mean of 580 DALYs/year/million population, with a maximum average of 1,021 DALYs/year/million population, and a maximum, single-year estimate for 1994 of 2,153 DALYs/million population. The most important input was the number of days lost to classic dengue. The DALYs/year/million population lost to dengue in Puerto Rico are much greater than previous estimates concerning the impact of dengue hemorrhagic fever alone. The loss to dengue is similar to the losses per million population in the Latin American and Caribbean region attributed to any of the following diseases or disease clusters; the childhood cluster (polio, measles, pertussis, diphtheria, tetanus), meningitis, hepatitis, or malaria. The loss is also of the same order of magnitude as any one of the following: tuberculosis, sexually transmitted diseases (excluding human immunodeficiency virus), tropical cluster (e.g., Chagas' disease, leishmaniasis), or intestinal helminths. The results objectively suggest that when governments and international funding agencies allocate resources for research and control, dengue should be given a priority equal to many other infectious diseases that are generally considered more important.
Assuntos
Dengue/economia , Modelos Econômicos , Adolescente , Adulto , Idade de Início , Criança , Pré-Escolar , Simulação por Computador , Avaliação da Deficiência , Humanos , Lactente , Pessoa de Meia-Idade , Porto Rico , Sensibilidade e EspecificidadeRESUMO
A survey was conducted from October 1, 1993 to June 30, 1995 to determine the arboviral etiologies of febrile illnesses in the city of Iquitos in the Amazon River Basin of Peru. The study subjects were patients who were enrolled at medical care clinics or in their homes by Peruvian Ministry of Health (MOH) workers as part of the passive and active disease surveillance program of the MOH. The clinical criterion for enrollment was the diagnosis of a suspected viral-associated, acute, undifferentiated febrile illness of < or = 5 days duration. A total of 598 patients were enrolled in the study. Demographic information, medical history, clinical data, and blood samples were obtained from each patient. The more common clinical features were fever, headache, myalgia, arthralgia, retro-ocular pain, and chills. Sera were tested for virus by the newborn mouse and cell culture assays. Viral isolates were identified initially by immunofluorescence using polyclonal antibody. An ELISA using viral-specific monoclonal antibodies and nucleotide sequence analysis were used to determine the specific variety of the viruses. In addition, thin and thick blood smears were observed for malaria parasites. Venezuelan equine encephalitis (VEE) virus subtype I, variety ID virus was isolated from 10 cases, including three cases in October, November, and December 1993, five cases in January and February 1994, and two cases in June 1995. The ELISA for IgM and IgG antibody indicated that VEE virus was the cause of an additional four confirmed and four presumptive cases, including five from January through March 1994 and three in August 1994. Sixteen cases were positive for malaria. The 18 cases of VEE occurred among military recruits (n = 7), agriculture workers (n = 3), students (n = 3), and general laborers (n = 5). These data indicated that an enzootic strain of VEE virus was the cause of at least 3% (18 of 598) of the cases of febrile illnesses studied in the city of Iquitos in the Amazon Basin region of Peru.
Assuntos
Encefalomielite Equina Venezuelana/diagnóstico , Encefalomielite Equina Venezuelana/epidemiologia , Adolescente , Adulto , Idoso , Instituições de Assistência Ambulatorial , Anticorpos Antivirais/análise , Células Cultivadas , Criança , Pré-Escolar , Vírus da Encefalite Equina Venezuelana/classificação , Vírus da Encefalite Equina Venezuelana/genética , Vírus da Encefalite Equina Venezuelana/imunologia , Encefalomielite Equina Venezuelana/sangue , Ensaio de Imunoadsorção Enzimática , Mapeamento de Epitopos , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Lactente , Malária/diagnóstico , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Peru/epidemiologia , Filogenia , Reação em Cadeia da Polimerase , Vigilância da População , RNA Viral/análise , RNA Viral/genética , Estudos Soroepidemiológicos , SorotipagemRESUMO
An outbreak of a febrile illness characterized by headache, ocular pain, myalgia, and arthralgia occurred during June 1994 among Peruvian army troops in Northern Peru. On June 14-16, 1994, clinical data and blood samples were obtained from eight soldiers with a febrile illness, and from 26 others who had a history of febrile illness during the past three months. A follow-up blood sample was obtained 107 days later from four of the febrile and seven of the afebrile soldiers. Serum samples were tested for dengue (DEN), Oropouche (ORO), and Venezuelan equine encephalitis (VEE) IgM and IgG antibodies by an enzyme-linked immunosorbent assay (ELISA). Virus isolation was performed by inoculation of newborn mice and Vero cell cultures. Viral isolates were identified by immunofluorescence, ELISA, and nucleotide sequencing. A VEE virus infection was confirmed in three of the eight febrile soldiers, two by virus isolation, and one by serology. Antigenic analysis indicated that one of the virus isolates was similar to VEE subtype I, variety ID, viruses previously isolated in Colombia and Venezuela. Nucleotide sequence data showed that both viral isolates were identical to one another and closely related to VEE ID viruses previously isolated in Peru, Colombia, and Venezuela. Serologic results showed that two of 26 afebrile soldiers had IgM antibody to VEE and four had IgG antibody to VEE; two febrile soldiers had IgG antibody in their first serum samples. Oropouche-specific IgM antibody was detected in one of the eight febrile and five of the afebrile soldiers, and 18 of the 34 soldiers had low titers of ORO IgG antibody titers, which did not meet the diagnostic criteria for confirmed cases. All soldiers were negative for DEN IgM antibody, and 10 had flavivirus IgG antibody that reacted with DEN antigens. These data indicated that VEE ID virus was one of the causes of illness among Peruvians soldiers and that this was the first association of this VEE subtype with human disease in Peru.
Assuntos
Infecções por Bunyaviridae/epidemiologia , Surtos de Doenças , Encefalomielite Equina Venezuelana/epidemiologia , Adolescente , Adulto , Animais , Anticorpos Antivirais/sangue , Infecções por Bunyaviridae/virologia , Vírus da Encefalite Equina Venezuelana/imunologia , Vírus da Encefalite Equina Venezuelana/isolamento & purificação , Encefalomielite Equina Venezuelana/virologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Camundongos , Orthobunyavirus , Peru/epidemiologia , Estudos Soroepidemiológicos , Vírus Simbu/imunologia , Vírus Simbu/isolamento & purificaçãoRESUMO
Dengue is endemic in Grenada and is grossly underreported and underestimated as a source of morbidity. Seroprevalence and knowledge, attitude and practice surveys were conducted in the area of Mount Tout/Grand Anse Valley in the parish of St George's. Many people were knowledgeable about the basics of dengue fever and mosquitoes, but knowledge of the important relationship between mosquitoes, human behaviour and disease transmission was absent. Results indicated that though most respondents (98 percent) reported never having dengue fever before, 93 percent had a positive IgG-ELISA test, indicating past exposure. This suggests that, although most people have basic knowledge of dengue, more education on the disease and vectors is required. Education and modified behavioural responses may help to reduce Ae. aegypti numbers and in turn help to prevent dengue fever and the most severe form, dengue hemorrhagic fever. (AU)
Assuntos
Humanos , Dengue/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Aedes , Insetos VetoresRESUMO
In 1986 Puerto Rico experienced its eleventh dengue outbreak of this century, but the first with simultaneous transmission of three dengue virus serotypes, and the first with significant numbers of severe and fatal hemorrhagic disease. Overall, 10,659 cases were reported; 1,257 cases were laboratory confirmed as having current or recent dengue infection. Dengue 4 (DEN-4) was the predominant serotype (160/363 isolates, 44%) followed by dengue 1 (DEN-1) with 134 isolates (37%) and dengue 2 (DEN-2), 69 isolates (19%). Transmission peaked during September, but large numbers of cases occurred through November. Seventy-one (91%) of Puerto Rico's 78 municipalities had laboratory-confirmed cases. Fifty-one percent of all confirmed cases occurred in metropolitan San Juan. Most cases presented clinically as classical dengue fever, but 37% of all confirmed cases were reported to have developed some type of hemorrhagic manifestation, and 6% reported hematemesis. In addition, 29 laboratory confirmed cases met the WHO case definition for dengue hemorrhagic fever, 3 of which were fatal. Among the 29 laboratory-confirmed cases of dengue hemorrhagic fever/ dengue shook syndrome, virus was isolated from 12; one DEN-1, three DEN-2, and eight DEN-4. Among laboratory confirmed cases, infants less than one year of age were at greater risk of developing dengue hemorrhagic fever/ dengue shook syndrome, hematemesis and any reported hemorrhage than were the other age groups evaluated.
Assuntos
Dengue/epidemiologia , Surtos de Doenças , Adolescente , Adulto , Distribuição por Idade , Criança , Pré-Escolar , Dengue/sangue , Dengue/virologia , Feminino , Humanos , Lactente , Recém-Nascido , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Vigilância da População , Porto Rico/epidemiologia , Fatores de Risco , Estações do Ano , Sorotipagem , Distribuição por SexoRESUMO
In 1986 Puerto Rico experienced its eleventh dengue outbreak of this century, but the first with simultaneous transmission of three dengue virus serotypes, and the first with significant numbers of severe and fatal hemorrhagic disease. Overall, 10,659 cases were reported; 1,257 cases were laboratory confirmed as having current or recent dengue infection. Dengue 4 (DEN-4) was the predominant serotype (160/363 isolates, 44 percent) followed by dengue 1 (DEN-1) with 134 isolates (37 percent) and dengue 2 (DEN-2), 69 isolates (19 percent). Transmission peaked during September, but large numbers of cases occurred through November. Seventy-one (91 percent) of Puerto Rico's 78 municipalities had laboratory-confirmed cases. Fifty-one percent of all confirmed cases occurred in metropolitan San Juan. Most cases presented clinically as classical dengue fever, but 37 percent of all confirmed cases were reported to have developed some type of hemorrhagic manifestation, and 6 percent reported hematemesis. In addition, 29 laboratory confirmed cases met the WHO case definition for dengue hemorrhagic fever, 3 of which were fatal. Among the 29 laboratory-confirmed cases of dengue hemorrhagic fever/ dengue shook syndrome, virus was isolated from 12; one DEN-1, three DEN-2, and eight DEN-4. Among laboratory confirmed cases, infants less than one year of age were at greater risk of developing dengue hemorrhagic fever/ dengue shook syndrome, hematemesis and any reported hemorrhage than were the other age groups evaluated
Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Dengue/epidemiologia , Surtos de Doenças , Distribuição por Idade , Dengue/sangue , Dengue/virologia , Testes de Função Hepática , Vigilância da População , Porto Rico/epidemiologia , Fatores de Risco , Estações do Ano , Sorotipagem , Distribuição por SexoRESUMO
The evolution of yellow fever virus over 67 years was investigated by comparing the nucleotide sequences of the envelope (E) protein genes of 20 viruses isolated in Africa, the Caribbean, and South America. Uniformly weighted parsimony algorithm analysis defined two major evolutionary yellow fever virus lineages designated E genotypes I and II. E genotype I contained viruses isolated from East and Central Africa. E genotype II viruses were divided into two sublineages: IIA viruses from West Africa and IIB viruses from America, except for a 1979 virus isolated from Trinidad (TRINID79A). Unique signature patterns were identified at 111 nucleotide and 12 amino acid positions within the yellow fever virus E gene by signature pattern analysis. Yellow fever viruses from East and Central Africa contained unique signatures at 60 nucleotide and five amino acid positions, those from West Africa contained unique signatures at 25 nucleotide and two amino acid positions, and viruses from America contained such signatures at 30 nucleotide and five amino acid positions in the E gene. The dissemination of yellow fever viruses from Africa to the Americas is supported by the close genetic relatedness of genotype IIA and IIB viruses and genetic evidence of a possible second introduction of yellow fever virus from West Africa, as illustrated by the TRINID79A virus isolate. The E protein genes of American IIB yellow fever viruses had higher frequencies of amino acid substitutions than did genes of yellow fever viruses of genotypes I and IIA on the basis of comparisons with a consensus amino acid sequence for the yellow fever E gene. The great variation in the E proteins of American yellow fever virus probably results from positive selection imposed by virus interaction with different species of mosquitoes or nonhuman primates in the Americas.
Assuntos
Evolução Biológica , Produtos do Gene env/genética , Genes env , Variação Genética , Febre Amarela/virologia , Vírus da Febre Amarela/genética , Aedes/virologia , África , Algoritmos , Sequência de Aminoácidos , Animais , Sequência de Bases , Região do Caribe , Sequência Consenso , Primers do DNA , Produtos do Gene env/química , Genótipo , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Primatas/virologia , RNA Viral/genética , Homologia de Sequência de Aminoácidos , América do Sul , Vírus da Febre Amarela/classificação , Vírus da Febre Amarela/isolamento & purificaçãoRESUMO
PROBLEM/CONDITION: Dengue is an acute, mosquito-transmitted viral disease characterized by fever, headache, arthralgia, myalgia, rash, nausea, and vomiting. The worldwide incidence of dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) increased from the mid-1970s through 1992. Although dengue is not endemic to the 50 United States, it presents a risk to U.S. residents who visit dengue-endemic areas. REPORTING PERIOD COVERED: 1986-1992. DESCRIPTION OF SYSTEM: Dengue surveillance in the 50 United States and the U.S. Virgin Islands relies on provider-initiated reports to state health departments. State health departments then submit clinical information and serum samples to CDC for diagnostic confirmation of disease among U.S. residents who become ill during or after travel to dengue-endemic areas and among residents of the U.S. Virgin Islands. In Puerto Rico, an active, laboratory-based surveillance program receives serum specimens from ambulatory and hospitalized patients throughout the island, clinical reports on hospitalized cases, and copies of death certificates that list dengue as a cause of death. Laboratory diagnosis relies on virus isolation or serologic diagnosis of disease (i.e., IgM or IgG antibodies against dengue viruses). RESULTS: In 1986, the first indigenous transmission of dengue in the United States in 6 years occurred in Texas; from the time of that incident through 1992, however, no further endemic transmission was reported. During 1986-1992, CDC processed serum samples from 788 residents of 47 states and the District of Columbia. Among these 788 residents, 157 (20%) cases of dengue were diagnosed serologically or virologically. Of the 157 patients, 71 (45%) had visited Latin America or the Caribbean; 63 (40%), Asia and the Pacific; seven (4%), Africa; and nine (6%), several continents. All four dengue virus serotypes (DEN-1, DEN-2, DEN-3, and DEN-4) were isolated from travelers to Asia and the Pacific; however, travelers to the Americas acquired infections with only DEN-1, DEN-2, or DEN-4. Even though the number of laboratory-diagnosed dengue infections among travelers was small, severe and fatal disease was documented. In the U.S. Virgin Islands and Puerto Rico, three serotypes (DEN-1, DEN-2, and DEN-4) circulated during 1986-1992. In Puerto Rico, disease transmission was characterized by a cyclical pattern, with peaks in incidence occurring during months with higher temperatures and humidity (usually from September through November). The highest incidence of laboratory-diagnosed disease (1.2 cases per 1,000 population) occurred among persons < 30 years of age; rates were similar for males and females.(ABSTRACT TRUNCATED AT 400 WORDS)
Assuntos
Dengue/epidemiologia , Animais , Culicidae , Dengue/diagnóstico , Dengue/transmissão , Vírus da Dengue/classificação , Vírus da Dengue/imunologia , Feminino , Humanos , Insetos Vetores , Masculino , Vigilância da População , Porto Rico/epidemiologia , Testes Sorológicos , Sorotipagem , Texas/epidemiologia , Viagem , Estados Unidos/epidemiologia , Ilhas Virgens Americanas/epidemiologiaRESUMO
We constructed a battery-powered backpack aspirator to collect adult Aedes aegypti mosquitoes. This simple, easily constructed aspirator facilitates the indoor collection of this important vector species. The collections made with the aspirator provide useful information about the biology and behavior of Ae. aegypti that can be used in education and vector control programs and in the evaluation of ultra-low volume insecticide spray programs directed against this species. The cost for construction is ca. $150.
Assuntos
Aedes , Entomologia/métodos , Animais , Entomologia/instrumentação , Desenho de Equipamento , Porto RicoRESUMO
Dengue viruses are maintained in endemic transmission cycles in tropical urban areas where epidemics periodically occur. Until about 30 years ago, there were long intervals (10-40 years) between epidemics but they are now occurring in many areas at 3-5-year intervals. These epidemics are most likely caused by virus strains with different epidemic potential. Accompanying this increased frequency in epidemic activity has been a change in the disease pattern with cases of the severe form of dengue (dengue hemorrhagic fever) becoming much more common. The occurrence of these factors and the expanding geographic distribution of dengue hemorrhagic fever in the past 15 years have made it necessary to re-evaluate currently recommended methods for prevention and control. The result has been increasing emphasis on the development of effective sustainable Aedes aegypti control programs based on source reduction using community participation. A brief overview of global programs using this approach is presented with emphasis on the Puerto Rican program, one of the earliest developed.
Assuntos
Aedes , Dengue/prevenção & controle , Insetos Vetores , Controle de Mosquitos/métodos , Animais , Ásia , América Central , Serviços de Saúde Comunitária , Humanos , México , Ilhas do Pacífico , Porto Rico , América do Sul , Índias OcidentaisRESUMO
En muchos países la vigilancia del sarampión depende, en gran medida, de la definición estándar de un caso clínico; sin embargo, los signos y síntomas clínicos del sarampión son similares a los del dengue. Por ejemplo, en 1985 se confirmó mediante exámenes serólogicos que 22 de 94 (23 por ciento) casos de enfermedad eruptiva cuyas características coincidían con la definición de casos clínicos de sarampión en Puerto Rico era, de hecho, sarampión, pero que otros 32 (34 por ciento) eran casos de dengue. El análisis retrospectivo efectuado en los laboratorios de los Centros para el Control de Enfermedades en San Juan también revelo que por lo menos 28 por ciento de todos los casos de dengue confirmados mediante pruebas de laboratorio en Puerto Rico en 1985 se ajustaban a la definición de casos clínicos de sarampión. Si suponemos que la eficacia verdadera (EV) de la vacuna antisarampionosa es de 90 por ciento, los casos de dengue que han sido confirmados en el laboratorio y que coinciden con la definición de casos clínicos de sarampión reducen la EV aparente de dicha vacuna a solo 64 por ciento (lo que representa una reducción de 29 por ciento en relación con la EV verdadera). Los resultados del estudio demuestran la importancia que tiene un sistema de vigilancia basado en pruebas de laboratorio para planear actividades de control o eliminación del sarampión en zonas donde el dengue es endémico
Se publica en inglés en Bull. WHO. Vol. 70(6), 1992
Assuntos
Sarampo , Dengue , Monitoramento Epidemiológico , Controle de Doenças Transmissíveis , Região do CaribeRESUMO
The incidence of dengue and dengue hemorrhagic fever has increased dramatically in the past 15 years in most urban centers of the tropics. Coincident with this increase has been the emergence of epidemic dengue hemorrhagic fever in the American region. The current changing disease pattern in the Americas is very similar to that which occurred in southeast Asia 30 years ago. The similarities in the evolution of severe disease in the two regions and the possible reasons for the changing disease pattern are discussed.
Assuntos
Vírus da Dengue/genética , Dengue/epidemiologia , Surtos de Doenças , Saúde Pública , Aedes , Animais , América Central/epidemiologia , Dengue/prevenção & controle , Dengue/transmissão , Vírus da Dengue/classificação , Humanos , Insetos Vetores , Epidemiologia Molecular , América do Norte/epidemiologia , América do Sul/epidemiologia , Clima TropicalRESUMO
An outbreak of dengue 4 occurred in the Yucatán, México in 1984. During the course of the outbreak, 538 of 5486 reported cases of dengue-like illness were studied; 200 were confirmed as dengue serologically and/or virologically. Dengue 4 virus was isolated from 34 patients and dengue 1 from one. Severe haemorrhagic symptoms were observed in 9 laboratory confirmed patients, including four deaths. Thus, the outbreak in Yucatán is the second dengue epidemic in the Americas after the Cuban epidemic in 1981 in which a number of patients suffered from haemorrhagic complications. It was notable that 5 of 9 hospitalized, severe cases were young adults and that only one met the WHO criteria of DHF, in contrast to primary pediatric nature of DHF in Southeast Asia. In this paper we describe clinical, serologic, and virologic studies conducted during the outbreak.