RESUMO
OBJECTIVES: This study sought to determine SV40 seroprevalence in residents of two Latin American countries, Colombia and Nicaragua, which were sites of prelicensure oral poliovaccine (OPV) trials. METHODS: Archival sera were tested for SV40 neutralizing antibody using a virus-specific plaque-reduction assay. Samples included 517 sera from Colombia and 149 sera from Nicaragua. RESULTS: Overall SV40 seroprevalence was 22.8% for Colombian subjects and 12.8% for Nicaraguans. Subgroups of Colombian subjects ranged in frequency of SV40 seropositivity from 10.0% to 38.6%. Birth cohorts both older and younger than the age cohort that contained potential OPV vaccinees from both countries had SV40 antibodies. Gender and ethnicity had no significant effects on SV40 seropositivity. CONCLUSIONS: Inhabitants of both Colombia and Nicaragua had detectable SV40 neutralizing antibody, including those of ages presumably not recipients of potentially SV40-contaminated OPV. This observation provides support for the concept that transmission of SV40 human infections can occur. Frequency of SV40 antibody positivity was elevated over that reported for the US where there was limited use of contaminated OPV. This investigation indicates also that study results of SV40 infections in humans will reflect whether subject populations had probable exposures to contaminated poliovaccines and to environmental conditions favoring cycles of viral transmission.
Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacina Antipólio Oral/administração & dosagem , Infecções por Polyomavirus/epidemiologia , Infecções por Polyomavirus/imunologia , Vírus 40 dos Símios/isolamento & purificação , Adolescente , Adulto , Bancos de Espécimes Biológicos , Criança , Estudos de Coortes , Colômbia/epidemiologia , Feminino , Humanos , Masculino , Nicarágua/epidemiologia , Estudos Soroepidemiológicos , Vacinação/estatística & dados numéricos , Adulto JovemRESUMO
BACKGROUND AND OBJECTIVES: Simian virus 40 (SV40) is an oncogenic DNA virus implicated in some human malignancies, including lymphomas. In the present masked case-control study, we investigated the prevalence of SV40 sequences and the expression of the viral oncoprotein, large tumor antigen (T-ag), in lymphomas and control specimens from patients negative for the human immunodeficiency virus in Costa Rica. DESIGN AND METHODS: Coded specimens were anlyzed by polymerase chain reaction for SV40 and Epstein-Barr virus (EBV). SV40 sequences were confirmed by Southern blot and DNA sequence analysis. Immunohistochemistry was used to detect the expression of SV40 T-ag in coded samples and to immunophenotype the lymphomas. RESULTS: When samples were decoded, SV40 DNA sequences were detected significantly more often in lymphomas than in control samples (30/125, 24% vs. 0/91, 0%; p=0.001). SV40 DNA was detected in 26% and 10% of non-Hodgkin's and Hodgkin's lymphomas, respectively. EBV DNA was detected in 10% of lymphomas and 33% of control specimens. None of the lymphomas was positive for both SV40 and EBV. Expression of SV40 T-ag was detected in 64% of B-cell lymphomas that contained T-ag DNA sequences and in none of the samples negative for viral DNA. Not all cells in a positive tumor expressed T-ag and the reactions were relatively low intensity. A germinal center B-cell-like profile was frequently associated with SV40-positive lymphomas. Of note, 20% of patients with SV40-related lymphomas were born in the 1970s and 1980s. INTERPRETATION AND CONCLUSIONS: These results indicate that SV40 is significantly associated with some B-cell neoplasms in Costa Rica today.