RESUMO
BACKGROUND: With a shortage of effective options for control of Aedes aegypti in Puerto Rico due to widespread resistance to conventional mosquito adulticides, an alternative approach was investigated to reduce vector populations. In two areas (totaling 144 ha) of the municipality of Bayamón, Puerto Rico, Bacillus thuringiensis israelensis (Bti) AM65-52 WDG was applied at a rate of 500 g/ha using vehicle-mounted aqueous wide-area larvicide spray applications weekly for 4 weeks and then every other week for a further 16 weeks. Bioassay jars were placed in the field to monitor for deposition of Bti droplets in open spaces, and under vegetation and building coverage. Autocidal gravid ovitraps were placed throughout the field site to monitor the population of adult female Ae. aegypti in both treatment and control sites. RESULTS: Larvicide spray was successfully deposited into jars in an array of open and covered locations, as confirmed by larval bioassays. After the fourth weekly spraying, differences in autocidal gravid ovitrap densities were observed between treatment and control sites resulting in 62% (P = 0.0001) and 28% (P < 0.0001) reductions in adult female Ae. aegypti numbers. CONCLUSION: Repeated wide-area larvicide spray application of Bti AM65-52 WDG to residential areas in Puerto Rico effectively suppressed dengue vector populations. The success of this trial has led to expansion of the WALS® program to a larger area of Bayamón and other municipalities in Puerto Rico. © 2020 Society of Chemical Industry.
Assuntos
Aedes , Bacillus thuringiensis , Animais , Feminino , Larva , Controle de Mosquitos , Mosquitos Vetores , Porto RicoRESUMO
In response to the 2016 Zika outbreak, Aedes aegypti mosquitoes from 38 locations across Puerto Rico were screened using Centers for Disease Control and Prevention bottle bioassays for sensitivity to insecticides used for mosquito control. All populations were resistant to pyrethroids. Naled, an organophosphate, was the most effective insecticide, killing all mosquitoes tested.
Assuntos
Aedes , Inseticidas , Controle de Mosquitos/métodos , Infecção por Zika virus/prevenção & controle , Animais , Feminino , Humanos , Resistência a Inseticidas , Naled , Porto Rico/epidemiologiaRESUMO
This investigation was initiated to control Aedes aegypti and Zika virus transmission in Caguas City, Puerto Rico, during the 2016 epidemic using Integrated Vector Management (IVM), which included community awareness and education, source reduction, larviciding, and mass-trapping with autocidal gravid ovitraps (AGO). The epidemic peaked in August to October 2016 and waned after April 2017. There was a preintervention period in October/November 2016 and IVM lasted until August 2017. The area under treatment (23.1 km2) had 61,511 inhabitants and 25,363 buildings. The city was divided into eight even clusters and treated following a cluster randomized stepped-wedge design. We analyzed pools of female Ae. aegypti adults for RNA detection of dengue (DENV), chikungunya (CHIKV), and Zika (ZIKV) viruses using 360 surveillance AGO traps every week. Rainfall, temperature, and relative humidity were monitored in each cluster. Mosquito density significantly changed (generalized linear mixed model; F8, 14,588 = 296; P < 0.001) from 8.0 ± 0.1 females per trap per week before the intervention to 2.1 ± 0.04 after the percentage of buildings treated with traps was 60% and to 1.4 ± 0.04 when coverage was above 80%. Out of a total 12,081 mosquito pools, there were 1 DENV-, 7 CHIKV-, and 49 ZIKV-positive pools from October 2016 to March 2017. Afterward, we found only one positive pool of DENV in July 2017. This investigation demonstrated that it was possible to scale up effective Ae. aegypti control to a medium-size city through IVM that included mass trapping of gravid Ae. aegypti females.
Assuntos
Aedes , Controle de Mosquitos/métodos , Mosquitos Vetores , Infecção por Zika virus/prevenção & controle , Aedes/virologia , Animais , Feminino , Educação em Saúde , Inseticidas , Mosquitos Vetores/virologia , Porto Rico , Zika virus/isolamento & purificação , Infecção por Zika virus/transmissãoRESUMO
Zika virus is a flavivirus transmitted primarily by Aedes aegypti and Aedes albopictus mosquitoes, and infection can be asymptomatic or result in an acute febrile illness with rash (1). Zika virus infection during pregnancy is a cause of microcephaly and other severe birth defects (2). Infection has also been associated with Guillain-Barré syndrome (GBS) (3) and severe thrombocytopenia (4,5). In December 2015, the Puerto Rico Department of Health (PRDH) reported the first locally acquired case of Zika virus infection. This report provides an update to the epidemiology of and public health response to ongoing Zika virus transmission in Puerto Rico (6,7). A confirmed case of Zika virus infection is defined as a positive result for Zika virus testing by reverse transcription-polymerase chain reaction (RT-PCR) for Zika virus in a blood or urine specimen. A presumptive case is defined as a positive result by Zika virus immunoglobulin M (IgM) enzyme-linked immunosorbent assay (MAC-ELISA)* and a negative result by dengue virus IgM ELISA, or a positive test result by Zika IgM MAC-ELISA in a pregnant woman. An unspecified flavivirus case is defined as positive or equivocal results for both Zika and dengue virus by IgM ELISA. During November 1, 2015-July 7, 2016, a total of 23,487 persons were evaluated by PRDH and CDC Dengue Branch for Zika virus infection, including asymptomatic pregnant women and persons with signs or symptoms consistent with Zika virus disease or suspected GBS; 5,582 (24%) confirmed and presumptive Zika virus cases were identified. Persons with Zika virus infection were residents of 77 (99%) of Puerto Rico's 78 municipalities. During 2016, the percentage of positive Zika virus infection cases among symptomatic males and nonpregnant females who were tested increased from 14% in February to 64% in June. Among 9,343 pregnant women tested, 672 had confirmed or presumptive Zika virus infection, including 441 (66%) symptomatic women and 231 (34%) asymptomatic women. One patient died after developing severe thrombocytopenia (4). Evidence of Zika virus infection or recent unspecified flavivirus infection was detected in 21 patients with confirmed GBS. The widespread outbreak and accelerating increase in the number of cases in Puerto Rico warrants intensified vector control and personal protective behaviors to prevent new infections, particularly among pregnant women.
Assuntos
Surtos de Doenças/prevenção & controle , Vigilância da População , Complicações Infecciosas na Gravidez/epidemiologia , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissão , Adolescente , Adulto , Infecções Assintomáticas/epidemiologia , Doadores de Sangue/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Prática de Saúde Pública , Porto Rico/epidemiologia , Características de Residência/estatística & dados numéricos , Fatores de Tempo , Adulto Jovem , Zika virus/isolamento & purificação , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/prevenção & controleRESUMO
Zika virus is a flavivirus transmitted primarily by Aedes species mosquitoes, and symptoms of infection can include rash, fever, arthralgia, and conjunctivitis (1).* Zika virus infection during pregnancy is a cause of microcephaly and other severe brain defects (2). Infection has also been associated with Guillain-Barré syndrome (3). In December 2015, Puerto Rico became the first U.S. jurisdiction to report local transmission of Zika virus, with the index patient reporting symptom onset on November 23, 2015 (4). This report provides an update to the epidemiology of and public health response to ongoing Zika virus transmission in Puerto Rico. During November 1, 2015-April 14, 2016, a total of 6,157 specimens from suspected Zika virus-infected patients were evaluated by the Puerto Rico Department of Health (PRDH) and CDC Dengue Branch (which is located in San Juan, Puerto Rico), and 683 (11%) had laboratory evidence of current or recent Zika virus infection by one or more tests: reverse transcription-polymerase chain reaction (RT-PCR) or immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA). Zika virus-infected patients resided in 50 (64%) of 78 municipalities in Puerto Rico. Median age was 34 years (range = 35 days-89 years). The most frequently reported signs and symptoms were rash (74%), myalgia (68%), headache (63%), fever (63%), and arthralgia (63%). There were 65 (10%) symptomatic pregnant women who tested positive by RT-PCR or IgM ELISA. A total of 17 (2%) patients required hospitalization, including 5 (1%) patients with suspected Guillain-Barré syndrome. One (<1%) patient died after developing severe thrombocytopenia. The public health response to the outbreak has included increased laboratory capacity to test for Zika virus infection (including blood donor screening), implementation of enhanced surveillance systems, and prevention activities focused on pregnant women. Vector control activities include indoor and outdoor residual spraying and reduction of mosquito breeding environments focused around pregnant women's homes. Residents of and travelers to Puerto Rico should continue to employ mosquito bite avoidance behaviors, take precautions to reduce the risk for sexual transmission (5), and seek medical care for any acute illness with rash or fever.
Assuntos
Surtos de Doenças/prevenção & controle , Vigilância da População , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Gravidez , Prática de Saúde Pública , Porto Rico/epidemiologia , Adulto Jovem , Zika virus/isolamento & purificação , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/prevenção & controleAssuntos
Aedes/crescimento & desenvolvimento , Aedes/genética , Controle de Insetos/métodos , Aedes/metabolismo , Animais , Animais Geneticamente Modificados , Simulação por Computador , Genes Letais/genética , Marcadores Genéticos/genética , Larva/química , Larva/genética , Proteínas Luminescentes/genética , Masculino , Índias Ocidentais , Proteína Vermelha FluorescenteRESUMO
The Grand Cayman population of Aedes aegypti is highly resistant to DDT and pyrethroid insecticides. Glutathione transferase, cytochrome P450, and esterase levels were increased in the Grand Cayman population relative to a susceptible laboratory strain, but synergist studies did not implicate elevated insecticide detoxification as a major cause of resistance. The role of target site resistance was therefore investigated. Two substitutions in the voltage-gated sodium channel were identified, V1016I in domain II, segment 6 (IIS6) (allele frequency = 0.79) and F1534C in IIIS6 (allele frequency = 0.68). The role of the F1534C mutation in conferring resistance to insecticides has not been previously established and so a tetraplex polymerase chain reaction assay was designed and used to genotype mosquitoes that had been exposed to insecticides. The F1534C mutation was strongly correlated with resistance to DDT and permethrin.
Assuntos
Aedes/efeitos dos fármacos , Resistência a Inseticidas , Inseticidas/farmacologia , Piretrinas/farmacologia , Aedes/genética , Aedes/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Bioensaio , DDT/farmacologia , Feminino , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Insetos Vetores/efeitos dos fármacos , Insetos Vetores/genética , Insetos Vetores/metabolismo , Canais de Sódio/genética , Índias OcidentaisRESUMO
Malaria is a growing problem in the Bolivian Amazon where there has been a four-fold increase between 1991 and 1998, largely owing to forest clearance bringing human and vector into closer association. The principle vector in this region is Anopheles darlingi Root, the behaviour of which has been little studied in this part of South America. The peak time of biting of A. darlingi was studied over a series of nights in July 2003 during the dry season in the town of Riberalta in the Bolivian Amazon. Peak biting occurred between 19:00 and 21:00 hours, when 48% of the total night's biting took place. This early biting habit has implications regarding control of malaria via the use of insecticide-treated bed nets. Anopheles darlingi was the most prevalent vector in the study, although A. albitarsis s.l. and A. braziliensis were also present.