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2.
Emerg Infect Dis ; 25(8): 1609-1611, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31158072

RESUMO

Evidence of spinal cord involvement in Powassan virus infection is largely limited to mouse models. We report a case of a polio-like illness caused by Powassan virus infection in a 62-year-old man in Canada. Magnetic resonance imaging showed T2 hyperintensities in the anterior horns of the cervical spinal cord.

3.
Vaccine ; 36(41): 6138-6143, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30181046

RESUMO

Newborns and infants less than 6 months of age continue to be at highest risk of severe outcomes from pertussis infection. Pertussis vaccination during the last trimester of pregnancy can confer protection to newborns as a result of trans-placental transfer of pertussis antibodies. In several countries, pertussis vaccination in pregnancy is recommended routinely and Canada's National Advisory Committee on Immunization issued similar routine recommendations in February 2018. Using second trimester biobanked plasma samples (n = 1752) collected between 2008 and 2011, we measured the pre-existing anti-pertussis toxin (PT) levels in a large cohort of second-trimester pregnant women using a commercial ELISA test. We found that 97.5% of these women had anti-PT IgG titres below 35 IU/mL. Women with higher incomes had slightly higher anti-PT levels but 96% still had titres <35 IU/ml. In conclusion, almost all of the pregnant women in this large cohort had anti-PT levels low enough to suggest susceptibility to pertussis infection in both the mothers and their newborn infants.

4.
Infect Genet Evol ; 51: 54-66, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28274887

RESUMO

Simian foamy viruses (SFVs) infect most nonhuman primate species and appears to co-evolve with its hosts. This co-evolutionary signal is particularly strong among great apes, including orangutans (genus Pongo). Previous studies have identified three distinct orangutan SFV clades. The first of these three clades is composed of SFV from P. abelii from Sumatra, the second consists of SFV from P. pygmaeus from Borneo, while the third clade is mixed, comprising an SFV strain found in both species of orangutan. The existence of the mixed clade has been attributed to an expansion of P. pygmaeus into Sumatra following the Mount Toba super-volcanic eruption about 73,000years ago. Divergence dating, however, has yet to be performed to establish a temporal association with the Toba eruption. Here, we use a Bayesian framework and a relaxed molecular clock model with fossil calibrations to test the Toba hypothesis and to gain a more complete understanding of the evolutionary history of orangutan SFV. As with previous studies, our results show a similar three-clade orangutan SFV phylogeny, along with strong statistical support for SFV-host co-evolution in orangutans. Using Bayesian inference, we date the origin of orangutan SFV to >4.7 million years ago (mya), while the mixed species clade dates to approximately 1.7mya, >1.6 million years older than the Toba super-eruption. These results, combined with fossil and paleogeographic evidence, suggest that the origin of SFV in Sumatran and Bornean orangutans, including the mixed species clade, likely occurred on the mainland of Indo-China during the Late Pliocene and Calabrian stage of the Pleistocene, respectively.


Assuntos
Genes Virais , Genoma Viral , Interações Hospedeiro-Patógeno/genética , Pongo/virologia , Infecções por Retroviridae/veterinária , Vírus Espumoso dos Símios/genética , Animais , Teorema de Bayes , Coevolução Biológica , Bornéu/epidemiologia , DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Fósseis , Expressão Gênica , História Antiga , Indonésia/epidemiologia , Pongo/classificação , Pongo/genética , Infecções por Retroviridae/epidemiologia , Infecções por Retroviridae/história , Infecções por Retroviridae/virologia , Vírus Espumoso dos Símios/classificação , Erupções Vulcânicas/história
5.
Infect Genet Evol ; 43: 434-50, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27245152

RESUMO

While human T-lymphotropic virus type 1 (HTLV-1) originates from ancient cross-species transmission of simian T-lymphotropic virus type 1 (STLV-1) from infected nonhuman primates, much debate exists on whether the first HTLV-1 occurred in Africa, or in Asia during early human evolution and migration. This topic is complicated by a lack of representative Asian STLV-1 to infer PTLV-1 evolutionary histories. In this study we obtained new STLV-1 LTR and tax sequences from a wild-born Bornean orangutan (Pongo pygmaeus) and performed detailed phylogenetic analyses using both maximum likelihood and Bayesian inference of available Asian PTLV-1 and African STLV-1 sequences. Phylogenies, divergence dates and nucleotide substitution rates were co-inferred and compared using six different molecular clock calibrations in a Bayesian framework, including both archaeological and/or nucleotide substitution rate calibrations. We then combined our molecular results with paleobiogeographical and ecological data to infer the most likely evolutionary history of PTLV-1. Based on the preferred models our analyses robustly inferred an Asian source for PTLV-1 with cross-species transmission of STLV-1 likely from a macaque (Macaca sp.) to an orangutan about 37.9-48.9kya, and to humans between 20.3-25.5kya. An orangutan diversification of STLV-1 commenced approximately 6.4-7.3kya. Our analyses also inferred that HTLV-1 was first introduced into Australia ~3.1-3.7kya, corresponding to both genetic and archaeological changes occurring in Australia at that time. Finally, HTLV-1 appears in Melanesia at ~2.3-2.7kya corresponding to the migration of the Lapita peoples into the region. Our results also provide an important future reference for calibrating information essential for PTLV evolutionary timescale inference. Longer sequence data, or full genomes from a greater representation of Asian primates, including gibbons, leaf monkeys, and Sumatran orangutans are needed to fully elucidate these evolutionary dates and relationships using the model criteria suggested herein.


Assuntos
Evolução Biológica , Infecções por Deltaretrovirus/transmissão , Vírus Linfotrópico T Tipo 1 Humano/genética , Filogenia , Vírus Linfotrópico T Tipo 1 de Primatas/genética , Vírus Linfotrópico T Tipo 1 de Símios/genética , Animais , Sequência de Bases , Teorema de Bayes , Infecções por Deltaretrovirus/epidemiologia , Infecções por Deltaretrovirus/história , Infecções por Deltaretrovirus/virologia , Produtos do Gene tax/genética , História Antiga , Vírus Linfotrópico T Tipo 1 Humano/classificação , Humanos , Macaca/virologia , Taxa de Mutação , Paleontologia , Pongo pygmaeus/virologia , Vírus Linfotrópico T Tipo 1 de Primatas/classificação , Vírus Linfotrópico T Tipo 1 de Símios/classificação , Sequências Repetidas Terminais
6.
J Clin Invest ; 125(12): 4421-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26551677

RESUMO

BACKGROUND: Ebola virus (EBOV) causes periodic outbreaks of life-threatening EBOV disease in Africa. Historically, these outbreaks have been relatively small and geographically contained; however, the magnitude of the EBOV outbreak that began in 2014 in West Africa has been unprecedented. The aim of this study was to describe the viral kinetics of EBOV during this outbreak and identify factors that contribute to outbreak progression. METHODS: From July to December 2014, one laboratory in Sierra Leone processed over 2,700 patient samples for EBOV detection by quantitative PCR (qPCR). Viremia was measured following patient admission. Age, sex, and approximate time of symptom onset were also recorded for each patient. The data was analyzed using various mathematical models to find trends of potential interest. RESULTS: The analysis revealed a significant difference (P = 2.7 × 10(-77)) between the initial viremia of survivors (4.02 log10 genome equivalents [GEQ]/ml) and nonsurvivors (6.18 log10 GEQ/ml). At the population level, patient viral loads were higher on average in July than in November, even when accounting for outcome and time since onset of symptoms. This decrease in viral loads temporally correlated with an increase in circulating EBOV-specific IgG antibodies among individuals who were suspected of being infected but shown to be negative for the virus by PCR. CONCLUSIONS: Our results indicate that initial viremia is associated with outcome of the individual and outbreak duration; therefore, care must be taken in planning clinical trials and interventions. Additional research in virus adaptation and the impacts of host factors on EBOV transmission and pathogenesis is needed.


Assuntos
Surtos de Doenças , Ebolavirus , Doença pelo Vírus Ebola/sangue , Doença pelo Vírus Ebola/mortalidade , Modelos Biológicos , Carga Viral , Anticorpos Antivirais/sangue , Feminino , Humanos , Imunoglobulina G/sangue , Masculino , Serra Leoa
8.
PLoS Med ; 12(4): e1001810, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25849352

RESUMO

BACKGROUND: Regional and subtype-specific mutational patterns of HIV-1 transmitted drug resistance (TDR) are essential for informing first-line antiretroviral (ARV) therapy guidelines and designing diagnostic assays for use in regions where standard genotypic resistance testing is not affordable. We sought to understand the molecular epidemiology of TDR and to identify the HIV-1 drug-resistance mutations responsible for TDR in different regions and virus subtypes. METHODS AND FINDINGS: We reviewed all GenBank submissions of HIV-1 reverse transcriptase sequences with or without protease and identified 287 studies published between March 1, 2000, and December 31, 2013, with more than 25 recently or chronically infected ARV-naïve individuals. These studies comprised 50,870 individuals from 111 countries. Each set of study sequences was analyzed for phylogenetic clustering and the presence of 93 surveillance drug-resistance mutations (SDRMs). The median overall TDR prevalence in sub-Saharan Africa (SSA), south/southeast Asia (SSEA), upper-income Asian countries, Latin America/Caribbean, Europe, and North America was 2.8%, 2.9%, 5.6%, 7.6%, 9.4%, and 11.5%, respectively. In SSA, there was a yearly 1.09-fold (95% CI: 1.05-1.14) increase in odds of TDR since national ARV scale-up attributable to an increase in non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance. The odds of NNRTI-associated TDR also increased in Latin America/Caribbean (odds ratio [OR] = 1.16; 95% CI: 1.06-1.25), North America (OR = 1.19; 95% CI: 1.12-1.26), Europe (OR = 1.07; 95% CI: 1.01-1.13), and upper-income Asian countries (OR = 1.33; 95% CI: 1.12-1.55). In SSEA, there was no significant change in the odds of TDR since national ARV scale-up (OR = 0.97; 95% CI: 0.92-1.02). An analysis limited to sequences with mixtures at less than 0.5% of their nucleotide positions­a proxy for recent infection­yielded trends comparable to those obtained using the complete dataset. Four NNRTI SDRMs­K101E, K103N, Y181C, and G190A­accounted for >80% of NNRTI-associated TDR in all regions and subtypes. Sixteen nucleoside reverse transcriptase inhibitor (NRTI) SDRMs accounted for >69% of NRTI-associated TDR in all regions and subtypes. In SSA and SSEA, 89% of NNRTI SDRMs were associated with high-level resistance to nevirapine or efavirenz, whereas only 27% of NRTI SDRMs were associated with high-level resistance to zidovudine, lamivudine, tenofovir, or abacavir. Of 763 viruses with TDR in SSA and SSEA, 725 (95%) were genetically dissimilar; 38 (5%) formed 19 sequence pairs. Inherent limitations of this study are that some cohorts may not represent the broader regional population and that studies were heterogeneous with respect to duration of infection prior to sampling. CONCLUSIONS: Most TDR strains in SSA and SSEA arose independently, suggesting that ARV regimens with a high genetic barrier to resistance combined with improved patient adherence may mitigate TDR increases by reducing the generation of new ARV-resistant strains. A small number of NNRTI-resistance mutations were responsible for most cases of high-level resistance, suggesting that inexpensive point-mutation assays to detect these mutations may be useful for pre-therapy screening in regions with high levels of TDR. In the context of a public health approach to ARV therapy, a reliable point-of-care genotypic resistance test could identify which patients should receive standard first-line therapy and which should receive a protease-inhibitor-containing regimen.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Sequência de Bases , Farmacorresistência Viral , Infecções por HIV/tratamento farmacológico , Transcriptase Reversa do HIV/genética , HIV-1/genética , Mutação , África , Américas , Fármacos Anti-HIV/farmacologia , Ásia , Europa (Continente) , Infecções por HIV/virologia , Transcriptase Reversa do HIV/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Humanos , Epidemiologia Molecular , Filogenia
9.
Can J Public Health ; 105(1): e53-62, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-24735698

RESUMO

OBJECTIVE: Regular HIV testing and early detection leads to timely treatment. Appropriate treatment and care can prevent disease progression in the individual and prevent onwards transmission within the community. This review describes HIV testing coverage in populations disproportionately affected by HIV and in the general population in Canada. METHODS: A search of published and grey literature on HIV testing uptake in Canada was conducted. Studies reporting quantitative data on testing practices (ever tested, recent testing, and regular testing), published in either English or French from 2008-2012, were included. Studies that involved testing for immigration or prenatal purposes, and post-intervention studies, were excluded. Included studies were assessed using a modified version of the Public Health Agency of Canada's Descriptive Study Critical Appraisal Tool. Pooled prevalence for percent ever tested was calculated for subpopulations and heterogeneity was estimated using the I2 statistic. SYNTHESIS: A total of 26 studies were included in the review. The highest rates of ever having been tested were among people who inject drugs (90.6%) and inmates (90.4%); followed by men who have sex with men (83.0%); Aboriginal peoples (55.5%); and the general population (32.8%). Limited information was available on regular and recent testing. CONCLUSION: HIV testing can reduce the number of undiagnosed cases in Canada. Future research should focus on testing coverage in certain populations, and on the extent to which populations engage in regular testing.


Assuntos
Infecções por HIV/prevenção & controle , Programas de Rastreamento/estatística & dados numéricos , Grupos Populacionais/estatística & dados numéricos , Canadá , Humanos
10.
BMC Infect Dis ; 13: 509, 2013 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-24171696

RESUMO

BACKGROUND: HIV transmitted drug resistance (TDR) surveillance is usually conducted by sampling from a large population. However, overall TDR prevalence results may be inaccurate for many individual clinical setting. We analyzed HIV genotypes at a tertiary care setting in Ottawa, Ontario in order to evaluate local TDR patterns among sub-populations. METHOD: Genotyping reports were digitized from ART naïve patients followed at the Immunodeficiency Clinic at the Ottawa Hospital, between 2008 and 2010. Quality controlled, digitized sequence data were assessed for TDR using the Stanford HIV Database. Patient characteristics were analyzed according to TDR patterns. Finally, a phylogenetic tree was constructed to elucidate the observed pattern of HIV TDR. RESULTS: Among the 155 clinic patients there was no statistically significantly difference in demographics as compared to the Ontario provincial HIV population. The clinic prevalence of TDR was 12.3%; however, in contrast to the data from Ontario, TDR patterns were inverted with a 21% prevalence among MSM and 5.5% among IDU. Furthermore, nearly 80% of the observed TDR was a D67N/K219Q pattern with 87% of these infections arising from a distinct phylogenetic cluster. CONCLUSIONS: Local patterns of TDR were distinct to what had been observed provincially. Phylogenetic analysis uncovered a cluster of related infections among MSM that appeared more likely to be recent infections. Results support a paradigm of routine local TDR surveillance to identify the sub-populations under care. Furthermore, the routine application of phylogenetic analysis in the TDR surveillance context provides insights into how best to target prevention strategies; and how to correctly measure outcomes.


Assuntos
Infecções por HIV/virologia , HIV-1/genética , Adulto , Fármacos Anti-HIV/farmacologia , Farmacorresistência Viral , Feminino , Genótipo , Infecções por HIV/epidemiologia , HIV-1/classificação , HIV-1/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Dados de Sequência Molecular , Ontário/epidemiologia , Filogenia , Prevalência , Saúde Pública , Adulto Jovem
11.
J Acquir Immune Defic Syndr ; 64(5): 443-7, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24231785

RESUMO

OBJECTIVE: To examine whether baseline clinical genotypes are equivalent to diagnostic serum genotypes for surveillance of HIV transmitted drug resistance (TDR). DESIGN: Current HIV TDR surveillance in Canada is conducted through genotyping remnant diagnostic sera from new HIV diagnoses. As part of routine care, baseline genotyping is now conducted on all newly diagnosed HIV infections, with TDR data being generated a second time on the same patients. METHODS: Surveillance genotyping, on HIV diagnostic serum, was performed on newly diagnosed HIV cases from 2007 to 2010 in Alberta, Canada. All subjects with a baseline clinical genotype result on file, and no evidence of antiretroviral therapy, were studied further. The HIV sequences from diagnosis and from the first clinical genotype were compared according to elapsed time between testing and by evaluating timing of infection based on BED capture enzyme immunoassay (BED-CEIA, abbreviated as BED in this article). RESULTS: Eighty-seven genotype pairs were available for analysis, most of which were subtype B. The time between genotypes ranged from 0 to 755 days, with a median of 36 days and an interquartile range of 155.25 days. Genetic distance between genotypes varied between 0 and 0.03389 substitutions per site and did not correlate with sampling times. There was a tendency for the genotypes of infections classified as recent by BED to be more similar to their clinical genotypes but this effect was lost when adjusted for elapsed time between tests. There was no difference in the identified drug resistance. CONCLUSIONS: Baseline clinical genotypes from treatment-naive patients may be used for HIV TDR surveillance.


Assuntos
Farmacorresistência Viral , Infecções por HIV/transmissão , Infecções por HIV/virologia , HIV/genética , HIV/isolamento & purificação , Alberta , Monitoramento Epidemiológico , Genótipo , Humanos
12.
Can J Public Health ; 104(4): e348-50, 2013 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-24044477

RESUMO

Phylogenetics is the application of comparative studies of genetic sequences in order to infer evolutionary relationships among organisms. This tool can be used as a form of molecular epidemiology to enhance traditional population-level communicable disease surveillance. Phylogenetic study has resulted in new paradigms being created in the field of communicable diseases and this commentary aims to provide the reader with an explanation of how phylogenetics can be used in tracking infectious diseases. Special emphasis will be placed upon the application of phylogenetics as a tool to help elucidate HIV transmission patterns and the limitations to these methods when applied to forensic analysis. Understanding infectious disease epidemiology in order to prevent new transmissions is the sine qua non of public health. However, with increasing epidemiological resolution, there may be an associated potential loss of privacy to the individual. It is within this context that we aim to promote the discussion on how to use phylogenetics to achieve important public health goals, while at the same time protecting the rights of the individual.


Assuntos
Infecções por HIV/genética , Filogenia , Vigilância em Saúde Pública/métodos , Infecções por HIV/epidemiologia , Direitos Humanos , Humanos , Epidemiologia Molecular , Medição de Risco
13.
PLoS One ; 8(7): e68213, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23935858

RESUMO

OBJECTIVE: In Mozambique, highly active antiretroviral treatment (HAART) was introduced in 2004 followed by decentralization and expansion, resulting in a more than 20-fold increase in coverage by 2009. Implementation of HIV drug resistance threshold surveys (HIVDR-TS) is crucial in order to monitor the emergence of transmitted viral resistance, and to produce evidence-based recommendations to support antiretroviral (ARV) policy in Mozambique. METHODS: World Health Organization (WHO) methodology was used to evaluate transmitted drug resistance (TDR) in newly diagnosed HIV-1 infected pregnant women attending ante-natal clinics in Maputo and Beira to non-nucleoside reverse transcriptase inhibitors (NNRTI), nucleoside reverse transcriptase inhibitors (NRTI) and protease inhibitors (PI). Subtypes were assigned using REGA HIV-1 subtyping tool and phylogenetic trees constructed using MEGA version 5. RESULTS: Although mutations associated with resistance to all three drug were detected in these surveys, transmitted resistance was analyzed and classified as <5% in Maputo in both surveys for all three drug classes. Transmitted resistance to NNRTI in Beira in 2009 was classified between 5-15%, an increase from 2007 when no NNRTI mutations were found. All sequences clustered with subtype C. CONCLUSIONS: Our results show that the epidemic is dominated by subtype C, where the first-line option based on two NRTI and one NNRTI is still effective for treatment of HIV infection, but intermediate levels of TDR found in Beira reinforce the need for constant evaluation with continuing treatment expansion in Mozambique.


Assuntos
Fármacos Anti-HIV/farmacologia , Farmacorresistência Viral , Genótipo , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Adolescente , Adulto , Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Farmacorresistência Viral/genética , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , HIV-1/classificação , Humanos , Masculino , Moçambique/epidemiologia , Mutação , Filogenia , Gravidez , Adulto Jovem
14.
J Int AIDS Soc ; 14: 39, 2011 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-21827673

RESUMO

BACKGROUND: Our objective was to describe the characteristics of acute and established HIV infections diagnosed in the Canadian province of British Columbia. Province-wide HIV testing and surveillance data were analyzed to inform recommendations for targeted use of screening algorithms to detect acute HIV infections. METHODS: Acute HIV infection was defined as a confirmed reactive HIV p24 antigen test (or HIV nucleic acid test), a non-reactive or reactive HIV EIA screening test and a non-reactive or indeterminate Western Blot. Characteristics of unique individuals were identified from the British Columbia HIV/AIDS Surveillance System. Primary drug resistance and HIV subtypes were identified by analyzing HIV pol sequences from residual sera from newly infected individuals. RESULTS: From February 2006 to October 2008, 61 individuals met the acute HIV infection case definition, representing 6.2% of the 987 newly diagnosed HIV infections during the analysis period. Acute HIV infection cases were more likely to be men who have sex with men (crude OR 1.71; 95% CI 1.01-2.89], to have had a documented previous negative HIV test result (crude OR 2.89; 95% CI 1.52-5.51), and to have reported a reason for testing due to suspected seroconversion symptoms (crude OR 5.16; 95% CI 2.88-9.23). HIV subtypes and rates of transmitted drug resistance across all classes of drugs were similar in persons with both acute and established HIV infections. CONCLUSIONS: Targeted screening to detect acute HIV infection is a logical public health response to the HIV epidemic. Our findings suggest that acute HIV infection screening strategies, in our setting, are helpful for early diagnosis in men who have sex with men, in persons with seroconversion symptoms and in previously negative repeat testers.


Assuntos
Técnicas de Laboratório Clínico/métodos , Infecções por HIV/diagnóstico , Programas de Rastreamento/métodos , Adulto , Idoso , Antígenos Virais/sangue , Colúmbia Britânica , Farmacorresistência Viral , Diagnóstico Precoce , Feminino , Genótipo , HIV/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , RNA Viral/genética
15.
J Acquir Immune Defic Syndr ; 55(1): 102-8, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20622676

RESUMO

OBJECTIVE: Through the application of simple, accessible, molecular epidemiology tools, we aimed to resolve the phylogenetic relationships that best predicted patterns of cluster growth using longitudinal population level drug resistance genotype data. METHODS: Analysis was performed on 971 specimens from drug naïve, first time HIV positive subjects collected in British Columbia between 2002 and 2005. A 1240bp fragment of the pol gene was amplified and sequenced with relationships among subtype B sequences inferred using Neighbour-Joining analysis. Apparent clusters of infections having both a mean within group distance <0.031 and bootstrap value >80% were systematically identified. The entire 2002-2005 dataset was then re-analyze to evaluate the relationship of subsequent infections to those identified in 2002. BED testing was used to identify recent infections (<156 days). RESULTS: Among the 2002 infections, 136 of 300 sequences sorted into 52 clusters ranging in size from 2 to 9 members. Aboriginal ethnicity and intravenous drug use were correlated, and both were linked to cluster membership in 2002. Although cluster growth between 2002 and 2005 was correlated with the size of the original cluster, more related infections were found in clusters seeded from nonclustered infections. Finally, all large growth clusters were seeded from infections that were much more likely to be recent. CONCLUSIONS: This population level phylogenetic analysis suggests that a greater increase in cluster size is associated with recently infected individuals, which may represent the leading edge of the epidemic. The most impressive increase in cluster size is seen originating from initially nonclustered infections. In contrast, smaller existing clusters likely describe historical patterns of transmission and do not substantially contribute to the ongoing epidemic. Application of this method for cross-sectional analysis of existing sequences from defined geographic regions may be useful in predicting trends in HIV transmission.


Assuntos
Farmacorresistência Viral , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , HIV/classificação , HIV/genética , Adolescente , Colúmbia Britânica/epidemiologia , Análise por Conglomerados , Estudos Transversais , Feminino , Genótipo , HIV/crescimento & desenvolvimento , HIV/isolamento & purificação , Infecções por HIV/transmissão , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Dados de Sequência Molecular , RNA Viral/genética , Análise de Sequência de DNA , Homologia de Sequência , Adulto Jovem , Produtos do Gene pol do Vírus da Imunodeficiência Humana/genética
17.
Transfusion ; 47(1): 162-70, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17207245

RESUMO

BACKGROUND: Simian foamy virus (SFV) is an endemic, nonhuman primate (NHP) retrovirus that is transmitted to individuals who work with or hunt NHPs. The cross-species transmission of simian retroviruses is believed to be the etiology of human immunodeficiency virus and human T-lymphotropic virus infections in humans. Although SFV is not pathogenic in the native host, the shared ancestry with other simian retroviruses has brought into question the potential for acquired pathogenicity after cross-species transmission. This study examines whether SFV also shares the traits of transmissibility through the blood supply. STUDY DESIGN AND METHODS: Within a controlled environment, blood from an SFV-infected monkey was transfused into an SFV-uninfected monkey. Evidence of infection, pathogenic effects, immune correlates, and viral shedding were followed for 6 months after transfusion. RESULTS: Molecular evidence of SFV infection manifested 8 weeks after transfusion followed by seroconversion 1 week later. Quantitative analysis demonstrated that the highest level of detectable virus was concomitant with seroconversion followed by establishment of a viral "set-point." Analysis of circulating lymphocytes revealed changes early in infection. Potential routes of transmission of SFV and roles of site-specific immune response are suggested by the late appearance of SFV shedding in the saliva of the transfused animal. CONCLUSION: The blood supply has historically provided a portal through which novel, occult viruses can become disseminated among humans. The demonstration of transmissibility of SFV through whole-blood transfusion, in an NHP model, contributes to the understanding of potential risks associated with blood donation by SFV-infected humans.


Assuntos
Sangue/virologia , Infecções por Retroviridae/transmissão , Spumavirus/isolamento & purificação , Reação Transfusional , Animais , Relação CD4-CD8 , Sistemas de Computação , DNA Viral/sangue , DNA Viral/metabolismo , Citometria de Fluxo , Linfonodos/virologia , Contagem de Linfócitos , Macaca fascicularis , Infecções por Retroviridae/sangue , Infecções por Retroviridae/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saliva/virologia , Fatores de Tempo , Carga Viral , Eliminação de Partículas Virais
18.
Lancet ; 360(9330): 387-8, 2002 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-12241782

RESUMO

Cross-species transmission of simian foamy virus (SFV) to human beings from chimpanzees, baboons, and African green monkeys has been described. Although macaques are the non-human primate most often handled in research, human infection with SFV from macaques has not been reported. Two of 46 primate-facility workers tested positive for antibodies that reacted with an immunoblot that contained macaque foamy virus antigens. Phylogenetic assessment of a 96-bp fragment of amplified proviral DNA isolated from peripheral-blood mononuclear cells from one infected individual was consistent with SFV infection of macaque origin. Frequent use of macaques in biomedical research, and identification of persistent retroviral infection from macaques to human beings, could have implications for public-health policy and occupational health and safety.


Assuntos
Antígenos Virais/sangue , Macaca/virologia , Exposição Ocupacional/efeitos adversos , Infecções por Retroviridae/transmissão , Spumavirus/imunologia , Animais , Cercopithecus aethiops , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pan troglodytes , Papio , Filogenia , Infecções por Retroviridae/sangue , Especificidade da Espécie , Spumavirus/isolamento & purificação , Inquéritos e Questionários
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