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2.
Rev Med Virol ; 16(6): 385-92, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17004294

RESUMO

Cytomegalovirus (CMV) infection is the most frequent congenital infection in humans and can cause permanent damage--particularly neurological--in about 20% of those infected, with or without symptoms at birth. Laboratory diagnosis is essential on account of the relatively non-specific clinical manifestations in symptomatic newborns but also because of the high frequency of asymptomatic cases that are nevertheless at risk of lesions later in life. However, these tests need samples taken within 3 weeks of birth to distinguish congenital infection from the more common, but clinically benign, perinatal infection. Tests for viral DNA have proved a valid means of diagnosing congenital CMV infection in neonatal blood dried on paper (DBS) widely used in screening for metabolic and genetic diseases, as an alternative to the conventional urine culture method. The DBS test is simpler, faster and less costly than viral isolation; in addition the samples can be safely stored for long periods, so diagnosis can be made even after several years. The sensitivity and specificity of the DBS test, compared to the reference method, have been reported to range between 71 and 100% and 99 and 100%, respectively, depending on the different studies and diagnostic criteria applied. The most interesting applications reported so far involve retrospective determination of the impact of congenital CMV in sensorineural deafness, abnormalities of cortical development, neonatal cholestasis and surveys of the prevalence of this infection in various populations. The test might be useful in the future for neonatal screening with a view to treating neonates and so avoiding the damage this disease can cause.


Assuntos
Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/congênito , Citomegalovirus/isolamento & purificação , DNA Viral/sangue , Citomegalovirus/genética , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/transmissão , Feminino , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Reação em Cadeia da Polimerase , Gravidez , Complicações Infecciosas na Gravidez/sangue , Complicações Infecciosas na Gravidez/virologia
3.
Pediatr Infect Dis J ; 25(2): 156-9, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16462294

RESUMO

BACKGROUND: Cytomegalovirus (CMV) infection is the most frequent congenital infection in humans. Its prevalence and the frequency of disabling sequelae must be assessed in different populations to permit the formulation or assessment of preventive measures. OBJECTIVES: To check the prevalence of congenital infection and seroprevalence in Italy; to verify the rate of sensorineural hearing loss (SNHL) in infected infants; and to assess the proportion of children with SNHL attributable to congenital CMV infection. METHODS: Diagnosis of congenital CMV infection was sought in 9032 children born between March 2002 and February 2003 by testing for viral DNA [CMV dried blood spot (DBS) test] in each newborn's Guthrie card and confirmation by isolation of CMV from urine collected in the first 3 weeks of life; CMV IgG testing in 1200 women of childbearing age; clinical and audiologic tests in the first 24 months for infected children; CMV DBS tests on the Guthrie cards collected from screening centers for 77 children (3 months-5 years) presenting SNHL of 40 dB or more. RESULTS: CMV infection was diagnosed in 14 asymptomatic and 2 symptomatic newborns (0.18%). CMV seroprevalence was 80%. In 2 infected infants, transient, unilateral SNHL was found. Nineteen of the 71 children with SNHL >70 dB were congenitally infected. CONCLUSIONS: The prevalence of congenital CMV infection is low in Italy. Population characteristics limiting the circulation of CMV strains in adult women might explain this. The fact that CMV contributes to significant SNHL highlights the need for preventive measures.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/epidemiologia , Citomegalovirus/imunologia , Citomegalovirus/isolamento & purificação , Adulto , Citomegalovirus/genética , Infecções por Citomegalovirus/complicações , DNA Viral/análise , Feminino , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/epidemiologia , Perda Auditiva Neurossensorial/etiologia , Humanos , Imunoglobulina G/sangue , Recém-Nascido , Masculino , Nascimento Prematuro , Prevalência , Estudos Soroepidemiológicos
4.
J Clin Virol ; 35(2): 206-9, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16384745

RESUMO

BACKGROUND: Congenital cytomegalovirus infection causes 20-30% of congenital sensorineural hearing loss (SNHL) cases. Early identification of CMV attributable cases and their successful treatment are often hampered by the late appearance of the damage in a high proportion of children both symptomatic and asymptomatic at birth. OBJECTIVE: To discuss the feasibility of a screening program aimed at finding congenitally infected babies followed by their audiological monitoring. STUDY DESIGN: Opinion-review article. RESULTS AND CONCLUSIONS: Frequency and severity of hearing loss due to congenital CMV suggest it maybe worthwhile setting up neonatal screening campaigns. Structures where SNHL can be diagnosed and treated exist already in many countries as part of universal neonatal audiological screening schemes. A test based on viral DNA extraction from neonatal dried blood spots on Guthrie cards and its amplification by means of a nested PCR (DBS test) seems to offer the best characteristics for use in screening. Clearly it will be necessary to calculate whether the costs of screening, diagnosis and follow-up, and the financial and emotional burden on the families of infected children, are up to the potential gain.


Assuntos
Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/complicações , Citomegalovirus/isolamento & purificação , Perda Auditiva Neurossensorial/etiologia , Citomegalovirus/genética , Infecções por Citomegalovirus/diagnóstico , DNA Viral/análise , DNA Viral/sangue , Perda Auditiva Neurossensorial/virologia , Humanos , Lactente , Recém-Nascido , Triagem Neonatal
5.
J Virol Methods ; 128(1-2): 1-5, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16023520

RESUMO

Human cytomegalovirus (HCMV) is the most frequent cause of congenital infection. Diagnosis of this infection is important because 5-17% of asymptomatic infected babies will develop late sequelae and should be followed closely. Most of these children will remain undetected, since screening of all newborns by viral culture is too expensive. The aim of this study was to demonstrate that pool testing could be used to detect HCMV congenital infection in newborns. For this purpose, a nested-PCR technique was tested in urine pools. In phase 1, urine specimens were tested alone by nested-PCR and compared with viral culture, followed by cross experiments to test the reliability of detecting one positive specimen in a 20 samples in a urine pool. In phase 2, this pool method was applied to all urine specimens from children received in the virology laboratory of the Centro Hospitalar Cova da Beira for diagnosis of HCMV infection, between January 2002 and March 2003. In phase 1, 74 urine specimens were tested simultaneously by shell-vial culture and nested-PCR; 17 were positive and the remaining 57 negative by both methods. The negative specimens were divided into three pools and each pool was tested alone and crossed with each of the positive specimens by nested-PCR. Although the three pools were negative when tested alone, all 51 crossed results were positive. In phase 2, 15 out of the 180 urine samples tested positive by shell-vial culture and were detected by this pool method. These results suggest that urine pools can be used to detect HCMV positive urines in children, with similar sensitivity and specificity when compared with the standard method, but with a substantial labour reduction. This significant reduction in labour and consequently in cost per test, opens the possibility of applying PCR to urine pools for screening the HCMV congenital infection in newborns.


Assuntos
Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/diagnóstico , Citomegalovirus/isolamento & purificação , DNA Viral/análise , Reação em Cadeia da Polimerase/métodos , Urina/virologia , Citomegalovirus/genética , Infecções por Citomegalovirus/virologia , Humanos , Recém-Nascido , Programas de Rastreamento , Sensibilidade e Especificidade , Cultura de Vírus
6.
J Clin Virol ; 30(3): 276-9, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15135749

RESUMO

BACKGROUND: Detection of viral DNA in dried blood spots using the Guthrie card (DBS test) is a reliable and practical method of diagnosing congenital cytomegalovirus (CMV) infection. The test lends itself to epidemiological studies to establish the prevalence of the infection, but also to neonatal screening for secondary prevention of sequelae. These applications would be facilitated if it were possible to use smaller samples and do the test on pools of individual cases. OBJECTIVE: To ascertain whether doing the test on smaller, pooled samples still accurately identifies neonates with congenital CMV infection. STUDY DESIGN: We tested DBS from: (A) 39 laboratory reference cases; (B) 156 neonates suspected of having congenital CMV infection; (C) 119 children examined for the retrospective diagnosis of congenital CMV; (D) mock specimens prepared with known amounts of viral DNA. RESULTS: The test using only one third of the usual amount of dried blood was 100% sensitive and specific compared to the standard DBS test (A) and to viral isolation (A and B). Pools of three single cases gave the same results as viral isolation (B) and the small-sample test (B and C). All the versions of the test gave a detection limit of 400 copies/ml. CONCLUSIONS: The modified procedure can accurately diagnose congenital CMV infection. It achieves savings in both the patient material and the costs of testing.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/diagnóstico , Citomegalovirus/isolamento & purificação , DNA Viral/sangue , Pré-Escolar , Citomegalovirus/genética , Infecções por Citomegalovirus/virologia , Humanos , Lactente , Reação em Cadeia da Polimerase/métodos , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade
7.
J Travel Med ; 11(1): 34-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14769285

RESUMO

BACKGROUND: Immunization against poliomyelitis is recommended for international travelers to developing countries. However, the level of antibodies varies even in previously unvaccinated persons, due to wild-type or vaccine-type infections in the eldest travelers. METHODS: In 1999, we conducted a seroprevalence study in the Lombardy region (northern Italy), using sera collected in 1994 from a population aged 50 to 59 years. The study subjects were consecutive, randomly selected travelers enrolled in an anti-hepatitis A virus antibody study. Neutralizing antibodies were titrated on Vero cells in microtiter plates. Each serum dilution (1:8 to 1:256) was challenged against 100 tissue culture infective doses of the three Sabin strains. Titers> 1:8 were considered to be protective. RESULTS: We studied 98 travelers, 59 male and 39 female, of mean age 54 years. Seventy-three (74.4%) reported previous travel abroad, but none had been vaccinated against polio. Dietary habits included consumption of seafood in 74.4% and raw vegetables from their own garden in 52.1%. The seroprevalences for neutralizing antibodies against poliovirus type 1, type 2 and type 3 were 86.7%, 89.9%, and 86.7%, respectively. All travelers presented protective antibody titers against at least one of the three viral types. Protective antibody titers were unrelated to travel history or dietary habit. CONCLUSIONS: A high proportion of the previously unvaccinated adults in our sample presented protective immunity to polioviruses. This observation may have implications for cost-effectiveness analysis of generalized polio vaccination in adult Italian travelers.


Assuntos
Anticorpos Antivirais/sangue , Poliomielite/epidemiologia , Poliomielite/prevenção & controle , Poliovirus/imunologia , Viagem , Adulto , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Poliomielite/etiologia , Poliomielite/imunologia , Estudos Soroepidemiológicos , Vacinação/estatística & dados numéricos
8.
Pediatr Infect Dis J ; 22(1): 39-42, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12544407

RESUMO

BACKGROUND: Diagnostic problems in identifying congenital infection cases in infancy have thus far impaired the assessment of the role of congenital cytomegalovirus (CMV) infection in the etiology of sensorineural hearing loss (SNHL). OBJECTIVE: To estimate the impact of congenital infection in children with SNHL by detection of CMV DNA in stored samples of neonatal dried blood (dried blood spots test). METHODS: The Guthrie cards of 130 children with hearing loss >40 dB hearing loss were retrieved from the regional screening center. CMV DNA was extracted by thermal shock and amplified by PCR. RESULTS: The percentage of SNHL cases attributable to congenital CMV infection was 10% (9 of 87) in infants whose SNHL had been diagnosed in their first 2 months of life and 34.2% (13 of 38) in children with deafness of unidentified cause that was diagnosed in early childhood. In the latter group 42.7% (12 of 28) of the children with a hearing loss of >70 dB were CMV-positive. CONCLUSIONS: The results suggest that congenital CMV infection has a more relevant role in the etiology of SNHL than previously reported. The data obtained in both groups suggest that 20 to 30% of all deafness cases are caused by CMV. The percent of congenital CMV cases alone appears to account for all the cases previously attributed to all congenital infections. More than 40% of deafness cases with an unknown cause, needing rehabilitation, are caused by congenital CMV.


Assuntos
Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/complicações , Perda Auditiva Neurossensorial/virologia , Pré-Escolar , Citomegalovirus/genética , Citomegalovirus/isolamento & purificação , DNA Viral/análise , DNA Viral/sangue , Perda Auditiva Neurossensorial/diagnóstico , Humanos , Lactente , Reação em Cadeia da Polimerase , Estudos Prospectivos
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