Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Infect Dis ; 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32052024

RESUMO

Persistence of Zika virus (ZIKV) RNA in semen is common after infection. We designed a RT-PCR assay that targets antisense ZIKV RNA (asRNA) to assess ZIKV replication competence in ZIKV RNA positive semen samples. We detected ZIKV asRNA in semen of nine of nineteen men (47.4%) diagnosed with ZIKV infection. All asRNA positive samples had high ZIKV loads (Ct-values <26) and were obtained within 21 days of symptom onset. The sensitivity of the asRNA assay for detection of ZIKV replication was higher than that of conventional virus isolation methods (47.4% vs. 21.1%, p-value 0.032).

2.
Infect Genet Evol ; 78: 104129, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31786339

RESUMO

Chikungunya virus (CHIKV), a positive-sense, single-stranded RNA virus in the family Togaviridae, is transmitted by Aedes mosquitoes. Of three known CHIKV genotypes, the Asian genotype was introduced into the Caribbean islands and rapidly spread throughout Central and South Americas. We previously found patients with symptoms compatible with chikungunya fever in 2014-2015 in Aruba, a Caribbean island of 180 km2. We here describe the full genome sequences of eight CHIKV strains isolated from patient sera of the Aruban outbreak. Phylogenetic analysis revealed that two closely related but distinct lineages of Asian-genotype CHIKV circulated simultaneously during the epidemic in 2014-2015. These results suggested that CHIKV was introduced into Aruba more than once in a short period, reflecting the importance of Aruba as a travel hub within the region.

3.
PLoS Negl Trop Dis ; 13(10): e0007765, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31593563

RESUMO

BACKGROUND: In endemic regions, asymptomatic Leishmania infection is common. In HIV patients, detection of asymptomatic Leishmania infection could potentially identify those at risk of visceral leishmaniasis (VL). However, data on the prevalence, incidence, and determinants of asymptomatic infection, and the risk of VL are lacking. METHODS: We conducted a cross-sectional survey at a single ART centre, followed by a prospective cohort study amongst HIV-infected adults in HIV care in a district hospital in a VL-endemic area in North-West Ethiopia (9/2015-8/2016). Asymptomatic Leishmania infection was detected using the direct agglutination test (DAT), rK39-rapid diagnostic test (RDT)), PCR on peripheral blood and the KAtex urine antigen test, and defined as positivity on any Leishmania marker. All individuals were followed longitudinally (irrespective of the Leishmania test results). Risk factors for asymptomatic Leishmania infection were determined using logistic regression. RESULTS: A total of 534 HIV-infected individuals enrolled in HIV care were included in the study. After excluding 13 patients with a history of VL and an 10 patients with incomplete baseline Leishmania tests, 511 were included in analysis. The median age was 38 years (interquartile range (IQR) 30-45), 62.6% were male. The median follow-up time was 12 months (IQR 9-12). No deaths were reported during the study period. Most (95.5%) were on antiretroviral treatment at enrolment, for a median of 52 months (IQR 27-79). The median CD4 count at enrolment was 377 cells/mm3 (IQR 250-518). The baseline prevalence of Leishmania infection was 12.8% in males and 4.2% in females. Overall, 7.4% tested positive for rK39, 4.3% for DAT, 0.2% for PCR and 0.2% for KAtex. Independent risk factors for a prevalent infection were male sex (odds ratio (OR) 3.2; 95% confidence intervals (CI) 14-7.0) and concurrent malaria infection (OR 6.1; 95% CI 1.9-18.9). Amongst the 49 prevalent (baseline) infections with further follow-up, the cumulative incidence of losing the Leishmania markers by one year was 40.1%. There were 36 incident infections during the course of the study, with a cumulative one-year risk of 9.5%. Only one case of VL was detected during follow-up. CONCLUSIONS: We found a high prevalence of asymptomatic Leishmania infection, persisting in most cases. The incidence was more modest and overt VL was rare. Larger and longer studies with more complete follow-up may help to decide whether a test and treat strategy would be justified in this context. TRIAL REGISTRATION: ClinicalTrials.gov NCT02839603.


Assuntos
Infecções Assintomáticas , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Leishmaniose/complicações , Leishmaniose/epidemiologia , Adolescente , Adulto , Testes de Aglutinação , Antirretrovirais/uso terapêutico , Contagem de Linfócito CD4 , Estudos Transversais , Testes Diagnósticos de Rotina , Etiópia/epidemiologia , Feminino , Humanos , Leishmaniose/diagnóstico , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Projetos Piloto , Prevalência , Estudos Prospectivos , Fatores de Risco , Adulto Jovem
4.
PLoS Negl Trop Dis ; 13(9): e0007047, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31487279

RESUMO

BACKGROUND: Pathogens causing acute fever, with the exception of malaria, remain largely unidentified in sub-Saharan Africa, given the local unavailability of diagnostic tests and the broad differential diagnosis. METHODOLOGY: We conducted a cross-sectional study including outpatient acute undifferentiated fever in both children and adults, between November 2015 and June 2016 in Kinshasa, Democratic Republic of Congo. Serological and molecular diagnostic tests for selected arboviral infections were performed on blood, including PCR, NS1-RDT, ELISA and IFA for acute, and ELISA and IFA for past infections. RESULTS: Investigation among 342 patients, aged 2 to 68 years (mean age of 21 years), with acute undifferentiated fever (having no clear focus of infection) revealed 19 (8.1%) acute dengue-caused by DENV-1 and/or DENV-2 -and 2 (0.9%) acute chikungunya infections. Furthermore, 30.2% and 26.4% of participants had been infected in the past with dengue and chikungunya, respectively. We found no evidence of acute Zika nor yellow fever virus infections. 45.3% of patients tested positive on malaria Rapid Diagnostic Test, 87.7% received antimalarial treatment and 64.3% received antibacterial treatment. DISCUSSION: Chikungunya outbreaks have been reported in the study area in the past, so the high seroprevalence is not surprising. However, scarce evidence exists on dengue transmission in Kinshasa and based on our data, circulation is more important than previously reported. Furthermore, our study shows that the prescription of antibiotics, both antibacterial and antimalarial drugs, is rampant. Studies like this one, elucidating the causes of acute fever, may lead to a more considerate and rigorous use of antibiotics. This will not only stem the ever-increasing problem of antimicrobial resistance, but will-ultimately and hopefully-improve the clinical care of outpatients in low-resource settings. TRIAL REGISTRATION: ClinicalTrials.gov NCT02656862.


Assuntos
Febre de Chikungunya/diagnóstico , Dengue/diagnóstico , Febre/diagnóstico , Adolescente , Adulto , Idoso , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/virologia , Vírus Chikungunya/genética , Vírus Chikungunya/isolamento & purificação , Vírus Chikungunya/fisiologia , Criança , Pré-Escolar , Estudos Transversais , República Democrática do Congo/epidemiologia , Dengue/epidemiologia , Dengue/virologia , Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Vírus da Dengue/fisiologia , Feminino , Febre/epidemiologia , Febre/virologia , Humanos , Malária/diagnóstico , Malária/epidemiologia , Masculino , Pessoa de Meia-Idade , Pacientes Ambulatoriais/estatística & dados numéricos , Adulto Jovem
5.
Vaccines (Basel) ; 7(3)2019 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-31450775

RESUMO

To combat emerging infectious diseases like Zika virus (ZIKV), synthetic messenger RNAs (mRNAs) encoding viral antigens are very attractive as they allow a rapid, generic, and flexible production of vaccines. In this work, we engineered a self-replicating mRNA (sr-mRNA) vaccine encoding the pre-membrane and envelope (prM-E) glycoproteins of ZIKV. Intradermal electroporation of as few as 1 µg of this mRNA-based ZIKV vaccine induced potent humoral and cellular immune responses in BALB/c and especially IFNAR1-/- C57BL/6 mice, resulting in a complete protection of the latter mice against ZIKV infection. In wild-type C57BL/6 mice, the vaccine resulted in very low seroconversion rates and antibody titers. The potency of the vaccine was inversely related to the dose of mRNA used in wild-type BALB/c or C57BL/6 mice, as robust type I interferon (IFN) response was determined in a reporter mice model (IFN-ß+/Δß-luc). We further investigated the inability of the sr-prM-E-mRNA ZIKV vaccine to raise antibodies in wild-type C57BL/6 mice and found indications that type I IFNs elicited by this naked sr-mRNA vaccine might directly impede the induction of a robust humoral response. Therefore, we assume that the efficacy of sr-mRNA vaccines after intradermal electroporation might be increased by strategies that temper their inherent innate immunogenicity.

7.
Eur J Clin Microbiol Infect Dis ; 38(4): 771-778, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30680570

RESUMO

Diagnosing a patient with Zika infection is not always straightforward. Here, we aim to describe our data collected from December 2015 to December 2017 and discuss the implemented algorithm and diagnostic challenges we encountered. At the National Reference Center for Arboviruses at the Institute of Tropical Medicine, Antwerp, Belgium (ITM), a commercial Zika virus (ZIKV) enzyme-linked immunosorbent assay (ELISA) detecting immunoglobulin (Ig) M and IgG, a commercial ZIKV immunofluorescence assay (IFA) detecting IgM, and an in-house Zika virus neutralization test (VNT) were implemented. For molecular detection of ZIKV, an in-house and a commercial real-time RT-PCR were applied. An algorithm, adapted from the European Centre for Disease Control and Prevention (ECDC), was implemented. Between December 2015 and December 2017, we tested 6417 patients for ZIKV. Of those, according to ECDC criteria, 127 (2.0%) were classified as a confirmed Zika infection of which 39 by RT-PCR (0.6%), 15 (0.2%) as a probable Zika infection, 73 (1.1%) as undefined, and 65 (1.0%) as false positive reactions. Main challenges were the brief window for detection of IgM, cross-reactivity of antibodies with other flaviviruses and malaria, and low VNT titers in the acute phase. In RT-PCR negative samples, classification of ZIKV infection as recent or past proved difficult, when IgM was negative. The majority of patients could be classified according to ECDC criteria, though 1.1% of patients remained "undefined" and 1.0% were ELISA false positive reactions. Complementary IFA IgM was of added value to increase IgM detection rates. Improved serological assays and more longitudinal data on antibody kinetics are needed.


Assuntos
Algoritmos , Técnicas de Laboratório Clínico/normas , Infecção por Zika virus/diagnóstico , Zika virus/isolamento & purificação , Adolescente , Adulto , Idoso , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , Técnicas de Laboratório Clínico/métodos , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Reações Falso-Positivas , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Gravidez , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Adulto Jovem , Zika virus/genética
8.
Travel Med Infect Dis ; 27: 107-114, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30205195

RESUMO

BACKGROUND: Zika virus (ZIKV) infection a concern to travellers because of potential sexual transmission and adverse pregnancy outcomes. OBJECTIVE: To describe our experience in diagnosing ZIKV in travellers returning from endemic territories. METHOD: Travellers were evaluated for ZIKV at our clinic in a 12-month period during the outbreak, using ZIKV-specific RT-PCR and anti-ZIKV Immunoglobulin M/G ELISA when symptomatic, and ELISA only for asymptomatic travellers, preferably from 20 days after the last exposure. All positive ELISA results were subject to confirmation by Virus Neutralization Testing. We estimated post-test probabilities of ZIKV in asymptomatic travellers. RESULTS: Of 462 travellers, 227 reported symptoms and 235 did not. Asymptomatic travellers had similar baseline characteristics, but were younger (median age 31 vs. 33 years, p = 0.01) and had reproductive concerns more often (75.8% vs. 24.2%). ZIKV infection was confirmed in 49 cases: 46/227 (20.3%) were symptomatic and 3/235 (1.3%) asymptomatic. Rash (positive likelihood ratio (LRP) 5.6) and conjunctivitis (LRP 10.8) predicted ZIKV infection. The post-test probability of a negative ELISA-result at 20-25 days was below 0.1%. CONCLUSION: ZIKV infection was frequent in symptomatic, but not in asymptomatic travellers. We consider negative ELISA results at 20-25 days after exposure a safe strategy to rule out ZIKV infection. Testing for ZIKV-specific antibodies within this timeframe could be particularly valuable in the management of returning travellers who wish to conceive.


Assuntos
Infecções Assintomáticas/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Doença Relacionada a Viagens , Infecção por Zika virus/epidemiologia , Adulto , Américas/epidemiologia , Conjuntivite/etiologia , Conjuntivite/virologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Europa (Continente)/epidemiologia , Exantema/etiologia , Exantema/virologia , Feminino , Humanos , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Gravidez , RNA Viral , Zika virus , Infecção por Zika virus/diagnóstico
9.
Int J Infect Dis ; 78: 39-43, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30368020

RESUMO

BACKGROUND: The incidence rate of Zika virus (ZIKV) infection in travellers from non-endemic areas to the Americas during the ZIKV outbreak in 2016 is unknown. METHODS: Belgian adults who planned to travel to South America, Central America, and the Caribbean were recruited prospectively to study the incidence and characteristics of ZIKV. Demographic data and sera were collected at baseline. Participants were trained to collect capillary blood on filter paper (BFP). When ill during travel, the participants completed a questionnaire and they sampled BFP for post-hoc analysis. All symptomatic participants were screened for ZIKV using ZIKV-specific RT-PCR on serum or urine, or BFP, and antibody detection assays (ELISA). Follow-up sera of asymptomatic travellers, obtained at least 20 days post travel, were tested by ZIKV ELISA only. All positive ELISA results were subject to confirmation by virus neutralization testing (VNT). RESULTS: Forty-nine participants completed follow-up: 38 women and 11 men, with a median age of 32 years (range 19-64 years). Travel destinations were countries in South America (n=20), Central America (n=24), and the Caribbean (n=5). The total travel duration was 67.8 person-months. Illness was reported by 24 participants (49.0%). ZIKV infection was confirmed in nine cases, by RT-PCR (n=5) and by VNT (n=4). Only one of nine ZIKV cases (11.1%) was asymptomatic. The ZIKV incidence rate was 17.0% (95% confidence interval 7.8-32.2%) per month of travel. CONCLUSIONS: The ZIKV incidence rate in adult travellers from non-endemic countries to the epidemic territories during the 2016 outbreak was high. Asymptomatic ZIKV infection was rare in this population.


Assuntos
Surtos de Doenças , Viagem , Infecção por Zika virus/etnologia , Adulto , Américas/epidemiologia , Bélgica/etnologia , Transmissão de Doença Infecciosa , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Doença Relacionada a Viagens , Adulto Jovem , Zika virus/isolamento & purificação
10.
Int J Infect Dis ; 79: 72-74, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30502485

RESUMO

Early schistosomiasis poses a serious diagnostic challenge, because current standard diagnostic techniques based on serology and egg microscopy lack sensitivity at the initial presentation. We report spinal cord neuroschistosomiasis in a traveller developing 6 weeks after exposure. The diagnosis was confirmed by Schistosoma mansoni-targeted real-time PCR in blood and cerebrospinal fluid, before the results of conventional methods became positive. Molecular assays represent a paradigm shift for the difficult diagnosis of early schistosomiasis and related complications.


Assuntos
Técnicas de Diagnóstico Molecular , Esquistossomose/diagnóstico , Animais , Costa do Marfim , Grupo com Ancestrais do Continente Europeu , Feminino , Humanos , Pessoa de Meia-Idade , Neuroesquistossomose/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real , Schistosoma mansoni/isolamento & purificação , Sensibilidade e Especificidade , Medula Espinal/parasitologia , Viagem
11.
PLoS One ; 13(4): e0196630, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29709007

RESUMO

BACKGROUND: Chikungunya virus (CHIKV) emerged in Aruba for the first time in 2014. We studied the clinical presentation of acute CHIKV infection and the contribution of serologic and molecular assays to its diagnosis. In a cohort of confirmed CHIKV cases, we analysed the frequency, duration and predictors of post-chikungunya chronic polyarthralgia (pCHIK-CPA), defined as joint pains lasting longer than 6 weeks or longer than 1 year. METHODOLOGY: Patient sera obtained within 10 days of symptom onset were tested for CHIKV, using an indirect immunofluorescence test for the detection of CHIKV-specific Immunoglobulin M (IgM) and post-hoc, by reverse-transcription polymerase chain reaction (RT-PCR). CHIKV was isolated from selected samples and genotyped. For confirmed CHIKV cases, clinical data from chart review were complemented by a Telephone survey, conducted 18-24 months after diagnosis. When joint pain was reported, the duration, presence of inflammatory signs, type and number of joints affected, were recorded. Joint involvement was scored according to the 2010 'American College of Rheumatology/ European League Against Rheumatism' criteria for seronegative rheumatoid arthritis (ACR-score). Risk factors for pCHIK-CPA were identified by logistic regression. PRINCIPAL FINDINGS: Acute CHIKV infection was diagnosed in 269 of 498 sera, by detection of IgM (n = 105), by RT-PCR (n = 59), or by both methods (n = 105). Asian genotype was confirmed in 7 samples. Clinical data were complete for 171 of 248 (69.0%) patients, aged 15 years or older (median 49.4 [35.0-59.6]). The female-to-male ratio was 2.2. The main acute symptoms were arthralgia (94%), fever (85%), myalgia (85%), headache (73%) and rash (63%). In patients with arthralgia (n = 160), pCHIK-CPA longer than 6 weeks was reported by 44% and longer than 1 year by 26% of cases. Inflammatory signs, stiffness, edema and redness were frequent (71%, 39% and 21%, respectively). Joints involved were knees (66%), ankles (50%), fingers (52%), feet (46%), shoulders (36%), elbows (34%), wrists (35%), hips (31%), toes (28.1%) and spine (28.1%). Independent predictors of pCHIK-CPA longer than 1 year were female gender (OR 5.9, 95%-CI [2.1-19.6]); high ACR-score (7.4, [2.7-23.3]), and detection of CHIKV-RNA in serum beyond 7 days of symptom onset (6.4, [1.4-34.1]. CONCLUSIONS: We identified 269 CHIKV patients after the first outbreak of Asian genotype CHIKV in Aruba in 2014-2015. RT-PCR yielded 59 (28%) additional CHIKV diagnoses compared to IgM antibody detection alone. Arthralgia, fever and skin rash were the dominant acute phase symptoms. pCHIK-CPA longer than 1 year affected 26% of cases and was predicted by female gender, high ACR-score and CHIKV-RNA detection beyond 7 days of symptom onset.


Assuntos
Artralgia/virologia , Febre de Chikungunya/complicações , Vírus Chikungunya/genética , Adolescente , Adulto , Anticorpos Antivirais/sangue , Artralgia/complicações , Artralgia/epidemiologia , Aruba , Febre de Chikungunya/epidemiologia , Doença Crônica , Estudos de Coortes , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Genótipo , Humanos , Imunoglobulina G/sangue , Articulações/patologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Inquéritos e Questionários , Resultado do Tratamento , Adulto Jovem
12.
Acta Clin Belg ; 73(5): 356-363, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28954600

RESUMO

Case report We report the case of a young Cameroonian woman who presented with cough, hyperthermia, weight loss, pancytopenia, and hepatosplenomegaly. A positive HIV serology was discovered and a chest radiography revealed a 'miliary pattern'. Bone marrow aspiration pointed out yeast inclusions within macrophages. Given the morphological aspect, the clinical presentation and immunosuppression, histoplasmosis was retained as a working hypothesis. Antiretroviral and amphotericin B treatments were promptly initiated. Review Given the immigration wave that Europe is currently experiencing, we think it is important to share experience and knowledge, especially in non-endemic areas such as Europe, where clinicians are not used to face this disease. Histoplasmosis is due to Histoplasma capsulatum var. capsulatum, a dimorphic fungus. Infection occurs by inhaling spores contained in soils contaminated by bat or bird droppings. The clinical presentation depends on the immune status of the host and the importance of inoculum, varying from asymptomatic to disseminated forms. AIDS patients are particularly susceptible to develop a severe disease. Antigen detection, molecular biology techniques, and microscopic examination are used to make a rapid diagnosis. However, antigen detection is not available in Europe and diagnosis needs a strong clinical suspicion in non-endemic areas. Because of suggestive imagery, clinicians might focus on tuberculosis. Our case illustrates the need for clinicians to take histoplasmosis in the differential diagnosis, depending on the context and the patient's past history.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS , Histoplasmose , Adulto , Anfotericina B/administração & dosagem , Anfotericina B/uso terapêutico , Antirretrovirais/administração & dosagem , Antirretrovirais/uso terapêutico , Antifúngicos/administração & dosagem , Antifúngicos/uso terapêutico , Células da Medula Óssea/microbiologia , Células da Medula Óssea/patologia , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Histoplasma , Humanos , Pancitopenia
13.
Bull World Health Organ ; 95(12): 802-809, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29200521

RESUMO

Objective: To prospectively monitor Zika viral loads in semen from Belgian travellers with confirmed Zika virus infection, who returned from the Americas during the 2016 Zika virus epidemic. Methods: We recruited symptomatic travellers consulting our clinic and we confirmed infection with either reverse-transcriptase (RT) polymerase chain reaction (PCR) assay or virus neutralization test. The participants produced semen samples weekly, either at the clinic or at home. For the initial sample, the laboratory staff did a microscopy analysis if they received the sample within an hour of production. Using RT-PCR, we monitored Zika virus ribonucleic acid (RNA) loads in semen until we obtained two negative results. Findings: We detected Zika virus RNA in nine of 15 participants' semen, one of whom was vasectomized. The median time to loss of RNA detection in semen was 83 days after symptom onset (95% confidence interval, CI: 57-108). The longest duration of viral shedding in semen before obtaining the first negative RT-PCR result was 144 days after symptom onset. All of the 11 participants, for whom we microscopically analysed their semen, had presence of leukocytes, 10 showed haematospermia and six showed oligospermia. These abnormalities occurred irrespective of Zika virus detection in semen. Conclusion: The majority of men in our study had detectable Zika virus RNA in their semen. We recommend that semen from Zika virus-infected men should be analysed with RT-PCR and that health professionals should advise infected men, even if they are vasectomized, about current recommendations for prevention of sexual transmission of the virus.


Assuntos
Doenças Transmissíveis Importadas/virologia , Sêmen/virologia , Viagem , Infecção por Zika virus/diagnóstico , Zika virus/isolamento & purificação , Adulto , Idoso , Américas , Bélgica , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Estudos Prospectivos , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Zika virus/genética , Infecção por Zika virus/virologia
14.
Malar J ; 16(1): 418, 2017 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-29041927

RESUMO

BACKGROUND: Light microscopy and antigen-based rapid diagnostic tests are the primary diagnostic tools for detecting malaria, although being labour-intensive and frequently challenged by lack of personnel's experience and low levels of parasite density. The latter being especially important in non-endemic settings. Novel molecular techniques aim to overcome this drawback. The objective of this study was to assess the diagnostic performance of the illumigene malaria assay® (Meridian Bioscience) compared to microscopy, RDT and real-time PCR. This loop-mediated isothermal amplification (LAMP) assay is a qualitative in vitro diagnostic test for the direct detection of Plasmodium spp. DNA in human venous whole blood samples. METHODS: The illumigene assay was assessed on a retrospective panel of stored blood samples (n = 103) from returned travellers and external quality control samples (n = 12). Additionally the assay was prospectively assessed on 30 fresh routine samples with a request for malaria diagnosis. The illumigene assay was compared to microscopy, RDT and Plasmodium species specific real-time PCR. RESULTS: In the retrospective evaluation, the illumigene assay showed 100% agreement with the real-time PCR, RDT and microscopy yielding a sensitivity and specificity of 100% (95% CI 95.1-100% and 89.7-100%, respectively). Seven samples from patients recently treated for Plasmodium falciparum infection that were RDT positive and microscopy negative yielded positive test results. The performance of the illumigene assay equals that of microscopy combined with RDT in the prospective panel with three false negative RDT results and one false negative microscopy result. Excellent concordance with PCR was observed. The limit of detection of the assay approached 0.5 parasites/µL for both P. falciparum and Plasmodium vivax. CONCLUSION: In non-endemic regions where the diagnostic process for malaria infections is questioned by lack of experience and low levels of parasite densities, the illumigene assay can be of value. Due to its high sensitivity, the LAMP assay may be considered as primary diagnostic test. The results of this study indicate that negative screen results do not need further confirmation. However, before implementation, this approach needs to be confirmed in larger, prospective studies. A shortcoming of this assay is that no species identification nor determination of parasite density are possible.


Assuntos
DNA de Protozoário/análise , Testes Diagnósticos de Rotina/métodos , Malária/diagnóstico , Microscopia/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Plasmodium/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Testes Diagnósticos de Rotina/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
15.
BMC Infect Dis ; 17(1): 478, 2017 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-28687071

RESUMO

BACKGROUND: Leishmaniasis is a protozoan disease caused by parasites of the genus Leishmania, transmitted to humans by sandflies. The diagnosis of leishmaniasis is often challenging as it mimics many other infectious or malignant diseases. The disease can present in three ways: cutaneous, mucocutaneous, or visceral leishmaniasis, which rarely occur together or consecutively. CASE PRESENTATION: The patient was a 52 years old immunosuppressed Belgian woman with a long history of severe rheumatoid arthritis. She underwent bone marrow biopsy to explore thrombocytopenia. Diagnosis of visceral leishmaniasis was made by identification of Leishman Donovan (LD) bodies in macrophages. Treatment with liposomal amphotericin B was successful. She later developed cutaneous leishmaniasis treated with amphotericin B lipid complex. She next presented with relapsing cutaneous lesions followed by rapidly progressing lymphadenopathies. Biopsy confirmed the diagnosis of leishmaniasis. Treatments by miltefosine, amphotericin B, N-methyl-glucamine antimoniate were subsequently initiated. She later presented a recurrent bone marrow involvement treated with intramuscular paromomycin and miltefosine. She died two years later from leukemia. At the time of death, she presented with a mucosal destruction of the nose. A Leishmania-specific PCR (Polymerase Chain Reaction) identified L. infantum as etiological agent. CONCLUSIONS: Clinicians should be aware of the potential concomitant or sequential involvement of multiple anatomic localizations of Leishmania in immunosuppressed patients.


Assuntos
Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/tratamento farmacológico , Anfotericina B/uso terapêutico , Antiprotozoários/uso terapêutico , Biópsia , Feminino , Humanos , Hospedeiro Imunocomprometido , Leishmania/genética , Leishmania/patogenicidade , Macrófagos/parasitologia , Pessoa de Meia-Idade , Paromomicina/uso terapêutico , Fosforilcolina/análogos & derivados , Fosforilcolina/uso terapêutico , Reação em Cadeia da Polimerase , Recidiva
16.
Open Forum Infect Dis ; 4(1): ofw273, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28480265

RESUMO

BACKGROUND: Rapid diagnostic test (RDT) detecting the nonstructural 1 (NS1) antigen is increasingly used for dengue diagnosis in endemic and nonendemic settings, but its clinical utility has not been studied in travel clinic practice. METHODS: From August 2012 to July 2016, travelers returning from the tropics with fever were evaluated in the Institute of Tropical Medicine (Antwerp, Belgium) with the routine use of NS1 antigen RDT that provided results within 1 hour. We determined the diagnostic performance, assessed the management of patients with a positive RDT result, and compared it with that of historical cases of dengue diagnosed from 2000 to 2006, when only antibody detection assays were available. RESULTS: Of 335 travelers evaluated for fever, 54 (16%) were diagnosed with dengue, including 1 severe case. Nonstructural 1 antigen RDT was performed in 308 patients. It was truly positive in 43 of 52 tested dengue cases and falsely positive in only 1 of the 256 nondengue cases; therefore, sensitivity was 82.7% (95% confidence interval [CI], 74.4%-93.0%) and specificity was 99.6% (95% CI, 98.8%-100%). Only 3 (7%) of the 43 febrile travelers "immediately" diagnosed by RDT were admitted, and only 2 (5%) were given empirical antibacterial treatment, without adverse outcome. Admission and antibiotic prescription rates were significantly higher in the historical cases (n = 43) diagnosed by antibody detection (33%, P = .006 and 26%, P = .014, respectively), although the frequency of severe dengue was similar. CONCLUSIONS: In our practice, the diagnostic performance of NS1 antigen RDT substantially contributed in withholding unnecessary hospitalization and antibiotherapy in dengue patients.

17.
BMC Infect Dis ; 17(1): 273, 2017 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-28407761

RESUMO

BACKGROUND: Rickettsiosis is a potential life threatening infectious disease in travelers. Clinical recognition is not always straightforward, as typical manifestations such as rash and/or eschar may be absent. Definite diagnosis is based on seroconversion and therefore often delayed until the convalescent phase of disease. CASE PRESENTATION: In this case report, we describe four patients with severe travel-related rickettsiosis (two patients with murine- and two patients with scrub typhus), in whom acute- phase diagnosis was possible by real-time polymerase chain reaction on serum or blood. CONCLUSIONS: Despite its limitations, we think that polymerase chain reaction can contribute significantly to the early diagnosis and treatment of rickettsial disease in travelers.


Assuntos
Orientia tsutsugamushi/genética , Rickettsia typhi/genética , Tifo por Ácaros/diagnóstico , Adulto , Animais , Anticorpos Antibacterianos/sangue , Bélgica , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Feminino , Humanos , Imunoglobulina G/sangue , Camundongos , Orientia tsutsugamushi/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Rickettsia typhi/isolamento & purificação , Tifo por Ácaros/microbiologia , Análise de Sequência de DNA , Viagem , Adulto Jovem
18.
Clin Infect Dis ; 63(12): 1626-1629, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27941144

RESUMO

Ten Belgian travelers returned from Mali with a Schistosoma haematobium-Schistosoma bovis hybrid infection, confirmed by DNA sequencing from eggs. Clinical symptoms and laboratory findings resembled those of classic acute schistosomiasis, but the detected eggs were morphologically unusual.


Assuntos
Hibridização Genética , Schistosoma haematobium , Esquistossomose/diagnóstico , Viagem , Animais , DNA de Helmintos , Fezes/parasitologia , Feminino , Técnicas de Genotipagem , Mali , Óvulo , Schistosoma/genética , Schistosoma haematobium/genética , Esquistossomose/parasitologia , Esquistossomose/terapia , Esquistossomose Urinária/diagnóstico , Esquistossomose Urinária/parasitologia , Esquistossomose Urinária/terapia
20.
J Infect Dis ; 214(suppl 3): S192-S202, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27247341

RESUMO

BACKGROUND: The 2013-2016 Ebola epidemic in West Africa resulted in accelerated development of rapid diagnostic tests for emergency outbreak preparedness. We describe the development and evaluation of the Idylla™ prototype Ebola virus test, a fully automated sample-to-result molecular diagnostic test for rapid detection of Zaire ebolavirus (EBOV) and Sudan ebolavirus (SUDV). METHODS: The Idylla™ prototype Ebola virus test can simultaneously detect EBOV and SUDV in 200 µL of whole blood. The sample is directly added to a disposable cartridge containing all reagents for sample preparation, RNA extraction, and amplification by reverse-transcription polymerase chain reaction analysis. The performance was evaluated with a variety of sample types, including synthetic constructs and whole blood samples from healthy volunteers spiked with viral RNA, inactivated virus, and infectious virus. RESULTS: The 95% limits of detection for EBOV and SUDV were 465 plaque-forming units (PFU)/mL (1010 copies/mL) and 324 PFU/mL (8204 copies/mL), respectively. In silico and in vitro analyses demonstrated 100% correct reactivity for EBOV and SUDV and no cross-reactivity with relevant pathogens. The diagnostic sensitivity was 97.4% (for EBOV) and 91.7% (for SUDV), the specificity was 100%, and the diagnostic accuracy was 95.9%. CONCLUSIONS: The Idylla™ prototype Ebola virus test is a fast, safe, easy-to-use, and near-patient test that meets the performance criteria to detect EBOV in patients with suspected Ebola.


Assuntos
Surtos de Doenças , Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , África Ocidental/epidemiologia , Ebolavirus/genética , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/virologia , Humanos , Técnicas de Diagnóstico Molecular/instrumentação , Técnicas de Diagnóstico Molecular/métodos , RNA Viral/análise , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/instrumentação , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA