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1.
Viruses ; 16(3)2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38543706

RESUMO

Following an Argentine Hemorrhagic Fever (AHF) outbreak in the early 1990s, a rodent survey for Junín virus, a New World Clade B arenavirus, in endemic areas of Argentina was conducted. Since 1990, INEVH has been developing eco-epidemiological surveillance of rodents, inside and outside the Argentine Hemorrhagic Fever endemic area. Samples from rodents captured between 1993 and 2019 that were positive for Arenavirus infection underwent Sanger and unbiased, Illumina-based high-throughput sequencing, which yielded 5 complete and 88 partial Mammarenaviruses genomes. Previously, 11 genomes representing four species of New World arenavirus Clade C existed in public records. This work has generated 13 novel genomes, expanding the New World arenavirus Clade C to 24 total genomes. Additionally, two genomes exhibit sufficient genetic diversity to be considered a new species, as per ICTV guidelines (proposed name Mammarenavirus vellosense). The 13 novel genomes exhibited reassortment between the small and large segments in New World Mammarenaviruses. This work demonstrates that Clade C Mammarenavirus infections circulate broadly among Necromys species in the Argentine Hemorrhagic Fever endemic area; however, the risk for Clade C Mammarenavirus human infection is currently unknown.


Assuntos
Arenaviridae , Arenavirus , Arenavirus do Novo Mundo , Febre Hemorrágica Americana , Vírus Junin , Animais , Humanos , Arenaviridae/genética , Roedores , Febre Hemorrágica Americana/epidemiologia , Argentina/epidemiologia , Arenavirus do Novo Mundo/genética , Vírus Junin/genética , Arenavirus/genética
3.
Clin Infect Dis ; 76(3): e849-e856, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35639875

RESUMO

BACKGROUND: Long-term persistence of Ebola virus (EBOV) in immunologically privileged sites has been implicated in recent outbreaks of Ebola virus disease (EVD) in Guinea and the Democratic Republic of Congo. This study was designed to understand how the acute course of EVD, convalescence, and host immune and genetic factors may play a role in prolonged viral persistence in semen. METHODS: A cohort of 131 male EVD survivors in Liberia were enrolled in a case-case study. "Early clearers" were defined as those with 2 consecutive negative EBOV semen test results by real-time reverse-transcription polymerase chain reaction (rRT-PCR) ≥2 weeks apart within 1 year after discharge from the Ebola treatment unit or acute EVD. "Late clearers" had detectable EBOV RNA by rRT-PCR >1 year after discharge from the Ebola treatment unit or acute EVD. Retrospective histories of their EVD clinical course were collected by questionnaire, followed by complete physical examinations and blood work. RESULTS: Compared with early clearers, late clearers were older (median, 42.5 years; P < .001) and experienced fewer severe clinical symptoms (median 2, P = .006). Late clearers had more lens opacifications (odds ratio, 3.9 [95% confidence interval, 1.1-13.3]; P = .03), after accounting for age, higher total serum immunoglobulin G3 (IgG3) titers (P = .005), and increased expression of the HLA-C*03:04 allele (0.14 [.02-.70]; P = .007). CONCLUSIONS: Older age, decreased illness severity, elevated total serum IgG3 and HLA-C*03:04 allele expression may be risk factors for the persistence of EBOV in the semen of EVD survivors. EBOV persistence in semen may also be associated with its persistence in other immunologically protected sites, such as the eye.


Assuntos
Ebolavirus , Doença pelo Vírus Ebola , Humanos , Masculino , Ebolavirus/genética , Doença pelo Vírus Ebola/epidemiologia , Sêmen , Libéria/epidemiologia , Estudos Retrospectivos , Antígenos HLA-C , Sobreviventes , Fatores de Risco
4.
N Engl J Med ; 386(24): 2283-2294, 2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35704480

RESUMO

BACKGROUND: In June 2019, the Bolivian Ministry of Health reported a cluster of cases of hemorrhagic fever that started in the municipality of Caranavi and expanded to La Paz. The cause of these cases was unknown. METHODS: We obtained samples for next-generation sequencing and virus isolation. Human and rodent specimens were tested by means of virus-specific real-time quantitative reverse-transcriptase-polymerase-chain-reaction assays, next-generation sequencing, and virus isolation. RESULTS: Nine cases of hemorrhagic fever were identified; four of the patients with this illness died. The etiologic agent was identified as Mammarenavirus Chapare mammarenavirus, or Chapare virus (CHAPV), which causes Chapare hemorrhagic fever (CHHF). Probable nosocomial transmission among health care workers was identified. Some patients with CHHF had neurologic manifestations, and those who survived had a prolonged recovery period. CHAPV RNA was detected in a variety of human body fluids (including blood; urine; nasopharyngeal, oropharyngeal, and bronchoalveolar-lavage fluid; conjunctiva; and semen) and in specimens obtained from captured small-eared pygmy rice rats (Oligoryzomys microtis). In survivors of CHHF, viral RNA was detected up to 170 days after symptom onset; CHAPV was isolated from a semen sample obtained 86 days after symptom onset. CONCLUSIONS: M. Chapare mammarenavirus was identified as the etiologic agent of CHHF. Both spillover from a zoonotic reservoir and possible person-to-person transmission were identified. This virus was detected in a rodent species, O. microtis. (Funded by the Bolivian Ministry of Health and others.).


Assuntos
Arenavirus do Novo Mundo , Febre Hemorrágica Americana , RNA Viral , Roedores , Animais , Arenavirus do Novo Mundo/genética , Arenavirus do Novo Mundo/isolamento & purificação , Bolívia/epidemiologia , Infecção Hospitalar/transmissão , Infecção Hospitalar/virologia , Transmissão de Doença Infecciosa , Febre Hemorrágica Americana/complicações , Febre Hemorrágica Americana/genética , Febre Hemorrágica Americana/transmissão , Febre Hemorrágica Americana/virologia , Febres Hemorrágicas Virais/genética , Febres Hemorrágicas Virais/transmissão , Febres Hemorrágicas Virais/virologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Reação em Cadeia da Polimerase , RNA Viral/genética , RNA Viral/isolamento & purificação , Ratos/virologia , Roedores/virologia , Zoonoses Virais/transmissão , Zoonoses Virais/virologia
5.
Emerg Infect Dis ; 28(2): 420-424, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35076001

RESUMO

After a pilot study, we tested 443 cadavers using OraQuick Ebola rapid diagnostic tests during surveillance after the 10th Ebola outbreak in the Democratic Republic of the Congo. No false negative and 2% false-positive results were reported. Quickly returning results and engaging the community enabled timely public health actions.


Assuntos
Ebolavirus , Doença pelo Vírus Ebola , República Democrática do Congo/epidemiologia , Testes Diagnósticos de Rotina , Surtos de Doenças , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/epidemiologia , Humanos , Projetos Piloto
6.
Emerg Infect Dis ; 27(2): 653-655, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33496248

RESUMO

The epidemiology of Rift Valley fever virus (RVFV) and Crimean-Congo hemorrhagic fever virus (CCHFV) in Jordan is unknown. Our investigation showed 3% of 989 tested dairy cattle, sheep, and goats were RVFV seropositive and 14% were CCHFV seropositive. Ongoing surveillance is needed to assess risk to humans and protect public health.


Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia/epidemiologia , Febre do Vale de Rift/epidemiologia , Vírus da Febre do Vale do Rift , Animais , Anticorpos Antivirais , Bovinos , Vírus da Febre Hemorrágica da Crimeia-Congo/imunologia , Febre Hemorrágica da Crimeia/veterinária , Jordânia/epidemiologia , Vírus da Febre do Vale do Rift/imunologia , Ruminantes , Ovinos , Zoonoses
7.
Clin Infect Dis ; 73(11): e3641-e3646, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-32894277

RESUMO

INTRODUCTION: Ebola virus (EBOV), species Zaire ebolavirus, may persist in the semen of male survivors of Ebola virus disease (EVD). We conducted a study of male survivors of the 2014-2016 EVD outbreak in Liberia and evaluated their immune responses to EBOV. We report here findings from the serologic testing of blood for EBOV-specific antibodies, molecular testing for EBOV in blood and semen, and serologic testing of peripheral blood mononuclear cells (PBMCs) in a subset of study participants. METHODS: We tested for EBOV RNA in blood by quantitative reverse transcription polymerase chain reaction (qRT-PCR), and for anti-EBOV-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies by enzyme-linked immunosorbent assay (ELISA) for 126 study participants. We performed PBMC analysis on a subgroup of 26 IgG-negative participants. RESULTS: All 126 participants tested negative for EBOV RNA in blood by qRT-PCR. The blood of 26 participants tested negative for EBOV-specific IgG antibodies by ELISA. PBMCs were collected from 23/26 EBOV IgG-negative participants. Of these, 1/23 participants had PBMCs that produced anti-EBOV-specific IgG antibodies upon stimulation with EBOV-specific glycoprotein (GP) and nucleoprotein (NP) antigens. CONCLUSIONS: The blood of EVD survivors, collected when they did not have symptoms meeting the case definition for acute or relapsed EVD, is unlikely to pose a risk for EBOV transmission. We identified 1 IgM/IgG negative participant who had PBMCs that produced anti-EBOV-specific antibodies upon stimulation. Immunogenicity following acute EBOV infection may exist along a spectrum, and absence of antibody response should not be exclusionary in determining an individual's status as a survivor of EVD.


Assuntos
Ebolavirus , Doença pelo Vírus Ebola , Anticorpos Antivirais , Ebolavirus/genética , Humanos , Leucócitos Mononucleares , Libéria/epidemiologia , Masculino , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Reversa , Sêmen , Sobreviventes
8.
JAMA Intern Med ; 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32692365

RESUMO

IMPORTANCE: Reported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection likely underestimate the prevalence of infection in affected communities. Large-scale seroprevalence studies provide better estimates of the proportion of the population previously infected. OBJECTIVE: To estimate prevalence of SARS-CoV-2 antibodies in convenience samples from several geographic sites in the US. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study performed serologic testing on a convenience sample of residual sera obtained from persons of all ages. The serum was collected from March 23 through May 12, 2020, for routine clinical testing by 2 commercial laboratory companies. Sites of collection were San Francisco Bay area, California; Connecticut; south Florida; Louisiana; Minneapolis-St Paul-St Cloud metro area, Minnesota; Missouri; New York City metro area, New York; Philadelphia metro area, Pennsylvania; Utah; and western Washington State. EXPOSURES: Infection with SARS-CoV-2. MAIN OUTCOMES AND MEASURES: The presence of antibodies to SARS-CoV-2 spike protein was estimated using an enzyme-linked immunosorbent assay, and estimates were standardized to the site populations by age and sex. Estimates were adjusted for test performance characteristics (96.0% sensitivity and 99.3% specificity). The number of infections in each site was estimated by extrapolating seroprevalence to site populations; estimated infections were compared with the number of reported coronavirus disease 2019 (COVID-19) cases as of last specimen collection date. RESULTS: Serum samples were tested from 16 025 persons, 8853 (55.2%) of whom were women; 1205 (7.5%) were 18 years or younger and 5845 (36.2%) were 65 years or older. Most specimens from each site had no evidence of antibodies to SARS-CoV-2. Adjusted estimates of the proportion of persons seroreactive to the SARS-CoV-2 spike protein antibodies ranged from 1.0% in the San Francisco Bay area (collected April 23-27) to 6.9% of persons in New York City (collected March 23-April 1). The estimated number of infections ranged from 6 to 24 times the number of reported cases; for 7 sites (Connecticut, Florida, Louisiana, Missouri, New York City metro area, Utah, and western Washington State), an estimated greater than 10 times more SARS-CoV-2 infections occurred than the number of reported cases. CONCLUSIONS AND RELEVANCE: During March to early May 2020, most persons in 10 diverse geographic sites in the US had not been infected with SARS-CoV-2 virus. The estimated number of infections, however, was much greater than the number of reported cases in all sites. The findings may reflect the number of persons who had mild or no illness or who did not seek medical care or undergo testing but who still may have contributed to ongoing virus transmission in the population.

9.
bioRxiv ; 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-32511332

RESUMO

Since emergence of SARS-CoV-2 in late 2019, there has been a critical need to understand prevalence, transmission patterns, to calculate the burden of disease and case fatality rates. Molecular diagnostics, the gold standard for identifying viremic cases, are not ideal for determining true case counts and rates of asymptomatic infection. Serological detection of SARS-CoV-2 specific antibodies can contribute to filling these knowledge gaps. In this study, we describe optimization and validation of a SARS-CoV-2-specific-enzyme linked immunosorbent assay (ELISA) using the prefusion-stabilized form of the spike protein [1]. We performed receiver operator characteristic (ROC) analyses to define the specificities and sensitivities of the optimized assay and examined cross reactivity with immune sera from persons confirmed tohave had infections with other coronaviruses. These assays will be used to perform contact investigations and to conduct large-scale, cross sectional surveillance to define disease burden in the population.

10.
J Infect Dis ; 222(8): 1311-1319, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32484879

RESUMO

BACKGROUND: During 2017, a multistate outbreak investigation occurred after the confirmation of Seoul virus (SEOV) infections in people and pet rats. A total of 147 humans and 897 rats were tested. METHODS: In addition to immunoglobulin (Ig)G and IgM serology and traditional reverse-transcription polymerase chain reaction (RT-PCR), novel quantitative RT-PCR primers/probe were developed, and whole genome sequencing was performed. RESULTS: Seventeen people had SEOV IgM, indicating recent infection; 7 reported symptoms and 3 were hospitalized. All patients recovered. Thirty-one facilities in 11 US states had SEOV infection, and among those with ≥10 rats tested, rat IgG prevalence ranged 2%-70% and SEOV RT-PCR positivity ranged 0%-70%. Human laboratory-confirmed cases were significantly associated with rat IgG positivity and RT-PCR positivity (P = .03 and P = .006, respectively). Genomic sequencing identified >99.5% homology between SEOV sequences in this outbreak, and these were >99% identical to SEOV associated with previous pet rat infections in England, the Netherlands, and France. Frequent trade of rats between home-based ratteries contributed to transmission of SEOV between facilities. CONCLUSIONS: Pet rat owners, breeders, and the healthcare and public health community should be aware and take steps to prevent SEOV transmission in pet rats and to humans. Biosecurity measures and diagnostic testing can prevent further infections.


Assuntos
Surtos de Doenças , Febre Hemorrágica com Síndrome Renal/transmissão , Doenças dos Roedores/transmissão , Vírus Seoul/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Cruzamento , Criança , Pré-Escolar , Técnicas de Laboratório Clínico/veterinária , Surtos de Doenças/veterinária , Genoma Viral/genética , Febre Hemorrágica com Síndrome Renal/diagnóstico , Febre Hemorrágica com Síndrome Renal/epidemiologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Lactente , Pessoa de Meia-Idade , Animais de Estimação/virologia , Filogenia , Prevalência , RNA Viral/genética , Ratos , Doenças dos Roedores/diagnóstico , Doenças dos Roedores/epidemiologia , Vírus Seoul/classificação , Vírus Seoul/genética , Vírus Seoul/imunologia , Estados Unidos/epidemiologia , Zoonoses Virais/diagnóstico , Zoonoses Virais/epidemiologia , Zoonoses Virais/transmissão , Adulto Jovem
11.
Open Forum Infect Dis ; 6(10): ofz404, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31660366

RESUMO

Seoul orthohantavirus (SEOV) infections, uncommonly reported in the United States, often result in mild illness. We report a case of hemophagocytic lymphohistiocytosis secondary to SEOV infection that was domestically acquired in Washington, DC.

12.
PLoS Negl Trop Dis ; 13(3): e0007257, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30883555

RESUMO

INTRODUCTION: In October 2017, a blood sample from a resident of Kween District, Eastern Uganda, tested positive for Marburg virus. Within 24 hour of confirmation, a rapid outbreak response was initiated. Here, we present results of epidemiological and laboratory investigations. METHODS: A district task force was activated consisting of specialised teams to conduct case finding, case management and isolation, contact listing and follow up, sample collection and testing, and community engagement. An ecological investigation was also carried out to identify the potential source of infection. Virus isolation and Next Generation sequencing were performed to identify the strain of Marburg virus. RESULTS: Seventy individuals (34 MVD suspected cases and 36 close contacts of confirmed cases) were epidemiologically investigated, with blood samples tested for MVD. Only four cases met the MVD case definition; one was categorized as a probable case while the other three were confirmed cases. A total of 299 contacts were identified; during follow- up, two were confirmed as MVD. Of the four confirmed and probable MVD cases, three died, yielding a case fatality rate of 75%. All four cases belonged to a single family and 50% (2/4) of the MVD cases were female. All confirmed cases had clinical symptoms of fever, vomiting, abdominal pain and bleeding from body orifices. Viral sequences indicated that the Marburg virus strain responsible for this outbreak was closely related to virus strains previously shown to be circulating in Uganda. CONCLUSION: This outbreak of MVD occurred as a family cluster with no additional transmission outside of the four related cases. Rapid case detection, prompt laboratory testing at the Uganda National VHF Reference Laboratory and presence of pre-trained, well-prepared national and district rapid response teams facilitated the containment and control of this outbreak within one month, preventing nationwide and global transmission of the disease.


Assuntos
Técnicas de Laboratório Clínico/métodos , Controle de Doenças Transmissíveis/métodos , Surtos de Doenças , Doença do Vírus de Marburg/epidemiologia , Doença do Vírus de Marburg/patologia , Marburgvirus/isolamento & purificação , Adulto , Animais , Análise por Conglomerados , Transmissão de Doença Infecciosa/prevenção & controle , Saúde da Família , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Doença do Vírus de Marburg/mortalidade , Pessoa de Meia-Idade , Mortalidade , Uganda/epidemiologia , Cultura de Vírus
13.
Emerg Infect Dis ; 25(6): 1241-1243, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30844358
15.
Am J Trop Med Hyg ; 88(1): 108-15, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23208881

RESUMO

The selection of vertebrate hosts by Culex mosquitoes relative to West Nile virus (WNV) transmission in neotropical countries such as Guatemala is not described. This study determined the feeding patterns of Cx. quinquefasciatus and Cx. nigripalpus and estimated the relative contribution of two common and frequently infected wild bird species, Turdus grayi and Quiscalus mexicanus, to WNV transmission. Engorged mosquitoes were collected from rural and urban habitats after the dry and wet seasons in the Department of Izabal in 2007. Host selection by Cx. nigripalpus varied significantly between urban and rural habitats. Both Cx. quinquefasciatus and Cx. nigripalpus fed predominantly on chickens and other domestic animals. Blood meals from wild birds were rare, accounting for 1.1% of blood meals identified from Cx. quinquefasciatus and 6.5% of blood meals from Cx. nigripalpus. Transmission of WNV by these two mosquito species may be dampened by extensive feeding on reservoir-incompetent hosts.


Assuntos
Aves/virologia , Culex/virologia , Insetos Vetores , Vírus do Nilo Ocidental/isolamento & purificação , Animais , Guatemala
16.
Am J Trop Med Hyg ; 88(1): 116-26, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23149586

RESUMO

West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States.


Assuntos
Ecossistema , Clima Tropical , Vírus do Nilo Ocidental/fisiologia , Animais , Aves/virologia , Culex/virologia , Guatemala , Humanos , Insetos Vetores , Vírus do Nilo Ocidental/isolamento & purificação
17.
J Clin Virol ; 55(1): 8-11, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22776162

RESUMO

BACKGROUND: In February 2009, a group of Guatemalan school children developed acute gastroenteritis (AGE) after participating in a school excursion. OBJECTIVES: We conducted a retrospective cohort investigation to characterize the outbreak and guide control measures. STUDY DESIGN: A case was defined as an illness with onset of diarrhea or vomiting during February 25-March 5, 2009. Participants were interviewed using a standardized questionnaire, and stool specimens were collected. We inspected the excursion site and tested water samples for total coliforms and Escherichia coli. RESULTS: We identified 119 excursion participants, of which 92 (77%) had been ill. Fifty-six (62%) patients sought care for their illness, and three (3%) were hospitalized. Eighteen (90%) of the 20 specimens from ill children tested positive for norovirus. Among these, 16 (89%) were of the genogroup I (GI.7) and two (11%) were genogroup II (GII.12 and GII.17). One (8%) of the 12 food handlers had norovirus (GI.7). Drinking water samples had 146 most probable numbers (MPN)/100ml of total coliforms and five MPN/100ml of E. coli. CONCLUSION: We describe the first laboratory-confirmed norovirus outbreak in Guatemala. The high illness attack rate, detection of multiple norovirus strains in sick persons, and presence of fecal contamination of drinking water indicate likely waterborne transmission.


Assuntos
Infecções por Caliciviridae/epidemiologia , Surtos de Doenças , Água Potável/microbiologia , Gastroenterite/epidemiologia , Norovirus/isolamento & purificação , Adulto , Infecções por Caliciviridae/virologia , Criança , Feminino , Manipulação de Alimentos , Gastroenterite/virologia , Guatemala/epidemiologia , Estâncias para Tratamento de Saúde , Humanos , Masculino , Norovirus/genética , Estudos Retrospectivos
18.
Acta Trop ; 123(1): 62-6, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22469818

RESUMO

In October 2010, the Ministry of Public Health and Population reported an outbreak of dengue-like acute febrile illness in Al Hodayda governorate. By January 2011, a total of 1542 cases had been recorded from 19 of the 26 districts in the governorate with 104 purportedly associated deaths. In response this event, in January 2011 entomological investigations aimed at identifying the primary vector and the epidemic associated etiological agent were carried out. Based on the reported cases and the progress of the outbreak in the governorate, mosquito collection was undertaken in two of the most recent outbreak areas; Al Khokha district (130km south of Al Hodayda) and Al Muneera district (100km north). Mosquito adults were collected from houses using BG-sentinel™ traps, aspiration of resting mosquitoes and knock-down spraying. Indoor and outdoor containers adjacent to the houses were inspected for larvae. Subsequently mosquito pools were analyzed by RT-PCR for detection of the four dengue virus serotypes (DENV-1, DENV-2, DENV-3, DENV-4), and for Chikungunya virus (CHIKV). Aedes aegypti was the dominant mosquito species collected. Four pools represent 40% of the tested pools, all containing adult female Ae. aegypti, were positive for CHIKV. Three CHIKV isolates were obtained from the RNA positive mosquito pools and identified by rRT-PCR. This finding marks the first record of CHIKV isolated from Ae. aegypti in Yemen. The larval container and Breteau indices in the visited localities surveyed were estimated at 53.8 and 100, respectively. The emergence of this unprecedented CHIKV epidemic in Al Hodayda is adding up another arboviral burden to the already existing vector-borne diseases. Considering the governorate as one focal port in the Red Sea region, the spread of the disease to other areas in Yemen and in neighboring countries is anticipated. Public health education and simple measures to detect and prevent mosquito breeding in water storage containers could prevent and reduce the spread of mosquito-borne viruses like CHIKV and DENV in Yemen.


Assuntos
Aedes/virologia , Vírus Chikungunya/isolamento & purificação , Dengue/epidemiologia , Surtos de Doenças , Animais , Feminino , Humanos , Masculino , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Iêmen/epidemiologia
19.
PLoS One ; 7(3): e32873, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22427902

RESUMO

The role wild bird species play in the transmission and ecology of avian influenza virus (AIV) is well established; however, there are significant gaps in our understanding of the worldwide distribution of these viruses, specifically about the prevalence and/or significance of AIV in Central and South America. As part of an assessment of the ecology of AIV in Guatemala, we conducted active surveillance in wild birds on the Pacific and Atlantic coasts. Cloacal and tracheal swab samples taken from resident and migratory wild birds were collected from February 2007 to January 2010.1913 samples were collected and virus was detected by real time RT-PCR (rRT-PCR) in 28 swab samples from ducks (Anas discors). Virus isolation was attempted for these positive samples, and 15 isolates were obtained from the migratory duck species Blue-winged teal. The subtypes identified included H7N9, H11N2, H3N8, H5N3, H8N4, and H5N4. Phylogenetic analysis of the viral sequences revealed that AIV isolates are highly similar to viruses from the North American lineage suggesting that bird migration dictates the ecology of these viruses in the Guatemalan bird population.


Assuntos
Patos , Vírus da Influenza A/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Filogenia , Animais , Sequência de Bases , Análise por Conglomerados , Demografia , Genótipo , Guatemala/epidemiologia , Modelos Genéticos , Dados de Sequência Molecular , Vigilância da População/métodos , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Análise de Sequência de DNA/veterinária
20.
PLoS One ; 6(11): e27459, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22076162

RESUMO

Dengue is caused by any of the four serotypes of dengue virus (DENV-1 to 4). Each serotype is genetically distant from the others, and each has been subdivided into different genotypes based on phylogenetic analysis. The study of dengue evolution in endemic regions is important since the diagnosis is often made by nucleic acid amplification tests, which depends upon recognition of the viral genome target, and natural occurring mutations can affect the performance of these assays. Here we report for the first time a detailed study of the phylogenetic relationships of DENV-2 from Central America, and report the first fully sequenced DENV-2 strain from Guatemala. Our analysis of the envelope (E) protein and of the open reading frame of strains from Central American countries, between 1999 and 2009, revealed that at least two lineages of the American/Asian genotype of DENV-2 have recently circulated in that region. In occasions the co-circulation of these lineages may have occurred and that has been suggested to play a role in the observed increased severity of clinical cases. Our time-scale analysis indicated that the most recent common ancestor for Central American DENV-2 of the American/Asian genotype existed about 19 years ago. Finally, we report positive selection in DENV-2 from Central America in codons of the genes encoding for C, E, NS2A, NS3, and NS5 proteins. Some of these identified codons are novel findings, described for the first time for any of the DENV-2 genotypes.


Assuntos
Vírus da Dengue/classificação , Vírus da Dengue/genética , Dengue/epidemiologia , Dengue/virologia , Evolução Molecular , Seleção Genética , América Central/epidemiologia , Dengue/genética , Vírus da Dengue/patogenicidade , Genoma Viral , Genótipo , Humanos , Filogenia , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Tempo
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