Genotypes of Epstein-Barr virus (EBV1/EBV2) in individuals with infectious mononucleosis in the metropolitan area of Belém, Brazil, between 2005 and 2016

Abstract Two types of Epstein Barr virus (EBV1/EBV2) have been shown to infect humans. Although their genomes are similar, the regions containing the EBNA genes differ. This study aimed to characterize the EBV genotypes of infectious mononucleosis (IM) cases in the metropolitan region of Belém, Brazil, from 2005 to 2016. A total of 8295 suspected cases with symptoms/signs of IM were investigated by infectious disease physicians at Evandro Chagas Institute, Health Care Service, from January 2005 to December 2016. Out of the total, 1645 (19.8%) samples had positive results for EBV by enzyme immunoassay and 251 (15.3%) were submitted to polymerase chain reaction (PCR) technique, using the EBNA3C region, in order to determine the type of EBV. Biochemical testing involving aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transferase were also performed. EBV type was identified by PCR in 30.3% (76/251) of individuals; of those, 71.1% (54/76) were classified as EBV1, 17.1% (13/76) as EBV2, and 11.8% (9/76) as EBV1+EBV2. The main symptoms/signs observed with EBV1 infection were cervical lymphadenopathy (64.8%, 35/54), fever (63%, 34/54), headache (20.4%, 11/54), arthralgia (20.4%, 11/54), and exanthema (18.5%, 10/54). EBV2 infection was detected in all but two age groups, with an average age of 24 years. The most common signs/symptoms of EBV2 were fever (76.9%, 10/13), average duration of 18 days, and lymphadenopathy (69.2%, 9/13). In contrast, EBV1+EBV2 coinfections were more frequent in those aged five years or less (20.0%, 2/10). The symptoms of EBV1+EBV2 coinfection included fever (66.7%, 6/9), and cervical lymphadenopathy and headache (33.3%, 3/9) each. The mean values of hepatic enzymes according to type of EBV was significantly different (p<0.05) in those EBV1 infected over 14 years of age. Thus, this pioneering study, using molecular methods, identified the EBV genotypes in 30.3% of the samples, with circulation of EBV1, EBV2, and EBV1+EBV2 co-infection in cases of infectious mononucleosis in the northern region of Brazil.

O vírus Epstein-Barr e a mononucleose infecciosa / Epstein-Barr virus and infectious mononucleosis

JUSTIFICATIVA E OBJETIVOS: A mononucleose infecciosa (MI) é uma doença viral, contagiosa, causada pelo vírus Epstein-Barr (EBV). Apresenta distribuição universal e pode ocorrer em qualquer faixa etária. O presente estudo teve como objetivo descrever a interação entre o EBV e o Homo sapiens sapiens, no que diz respeito especialmente à MI. Para isso, realizou busca no Pubmed e no Scielo, bem como em livros-textos. Os artigos selecionados foram lidos e as informações organizadas de forma a contemplar os aspectos patogênicos - enfatizando o papel do EBV na doença -, epidemiológicos e diagnósticos dessa entidade. CONTEÚDO: A infecção do epitélio da orofaringe permite a replicação do vírus, o qual passa a ser eliminado na saliva, o que explica a transmissão pelo contato com tal fluido biológico. O período de incubação é de quatro a seis semanas. Manifesta-se do ponto de vista clínico, usualmente, com febre, faringite e linfadenomegalia generalizada de caráter agudo ou subagudo. As alterações laboratoriais incluem leucocitose, reações leucemoides, trombocitopenia e anemia hemolítica autoimune, além de aminotransferases elevadas e bilirrubina aumentada, destacando-se que a linfocitose atípica é habitualmente observada. O diagnóstico diferencial da MI abrange as demais causas de síndrome de mononucleose. O tratamento é sintomático, não havendo fármaco antiviral específico. Analgésicos habituais podem ser usados para a terapêutica da dor. CONCLUSÃO: Díspares grupos têm trabalhando no desenvolvimento de vacinas para o EBV, porém, a possibilidade de tumorigênese pelo vírus tem trazido inúmeras dificuldades para a confecção de imunoprofilaxia efetiva.

BACKGROUND AND OBJECTIVES: Infectious mononucleosis (IM) is a widespread viral disease caused by Epstein-Barr virus (EBV). It occurs worldwide and can reach any age group. This article aims at describing the interaction between EBV and Homo sapiens sapiens, regarding especially IM. Thus, a research on PubMed and Scielo was performed, as well as on books. The selected articles were read and the information was organized inorder to contain the pathological - emphasizing the role of EBV on the disease -, epidemiological aspects and its diagnosis. CONTENTS: The infection of the epithelium of the oropharynx leads to the replication of the virus, which is eliminated via saliva, and accounts for the transmission through contact with this biological fluid. The incubation period lasts from four to six weeks. Clinically, the classic symptoms are usually fever, faryngitis and generalized lymphadenopathy, which can be acute or subacute. The laboratorial changes include leukocytosis, leukemoid reactions, thrombocytopenia and severe autoimmune hemolytic anemia, besides high levels of transaminases and bilirubin; atypical lymphocytosis is usually observed. The differential diagnosis of IM includes the other causes of mononucleosis syndrome. Treatment is symptomatic and there is not a specific antiviral medicine. Common analgesics can be used to treat pain. CONCLUSION: Diverse groups have worked on the development of a vaccine for EBV; however, the possibility of tumorigenesis by the virus has brought up several difficulties to the production of an effective immunoprophylaxis.

Seroprevalencia de infección por virus de Epstein Barr en población sana de Santiago de Chile / Seroprevalence of Epstein Barr's virus infection in healthy population at Santiago de Chile

To study the rate of infection by Epstein Barr virus (EBV) in Santiago, Chile, the prevalence of antibody to the viral capsid antigen (VCA-IgG) was determined in a group of 663 helthy individuals grouped by age and socioeconomic level (SEL). In addition, several risk factors for infection were studied. VCA-IgG was determined by ELISA. The total prevalence was 76,6 percent. When grouped by age and SEL, 50 percent of the children from low and medium SEL had been already infected by the age two, compared to 5,9 percent in the high SEL (p<0.01). However, by age twenty, 90 percent of the total sample had already specific antibodies to EBV. Age and number of household members were positively associated with the infection. High socioeconomic level represented a delay factor in the acquisition of the virus, (p<0.01). These results show that EBV infection is frequent in Santiago, occurring early in childhood among medium and low SEL. Hence, the classical infectious mononucleosis should be recognized more frequently among adolescents and young adults belonging to high SEL, while the clinical spectrum of associated manifestations different from the typical mononucleosis syndrome should be investigated among those exposed in early age

Prevalencia del virus Epstein-Barr en niños y adolescentes cubanos / Prevalence of Epstein-Barr virus in cuban children and adolescents

El objetivo de este estudio fue conocer la prevalencia del virus Epstein-Barr en niños y adolescentes y su relación con la incidencia de la mononucleosis infecciosa. Los resultados se compararon con los de estudios análogos realizados en otros países

Mononucleosis infecciosa crónica: a propósito del primer caso publicado en Costa Rica / Chronic infectious mononucleosis: apropos of the first published report in Costa Rica

La mononucleosis infecciosa es una enfermedad producida por el virus de Epstein-Barr, perteneciente a la familia de los Herpesvirus. El cuadro clínico clásico se caracteriza por fiebre, linfadenopatías, faringitis, linfocitosis con linfocitos atípicos en sangre periférica y presencia de anticuerpos heterófilos. Su evolución es benigna, de corta duración y autolimitada. No obstante, en algunos pacientes ha sido demostrado un curso más prolongado, lo que se ha denominado mononucleosis infecciosa crónica. Esta entidad ha sido bien definida clínicamente. Serológicamente se detecta un aumento de los anticuerpos contra el antígeno de la cápside y contra el antígeno precoz del virus Epstein-Barr. Se ha observado que en la mayoría de estos pacientes existe una actividad anormal de linfocitos T supresores. En el presente trabajo, se analiza el primer paciente con esta enfermedad reportado en Costa Rica, y se discuten los hallazgos