title: Natural human infections with Vaccinia virus during bovine vaccinia outbreaks.
abstract: BACKGROUND
  Bovine vaccinia is an exanthematic disease caused by Vaccinia virus (VACV). This zoonosis has been associated with several cases of bovine infection, particularly in milk herds. Farmers, milkers and their close contacts developed lesions on the hands, forearms, legs and face accompanied by fever, headache, malaise, myalgia and axillary, inguinal and cervical lymphadenopathy. VACV infections have a significant public health impact due to their occupational character, high frequency of transmission and the improper medical treatment often applied.
  
  
  OBJECTIVE
  To study natural human infection by VACV and to analyze clinical and epidemiological aspects, emphasizing the patients' immunological status.
  
  
  METHODS
  Ninety-eight individuals from rural properties with bovine vaccinia (BV) outbreaks who were at risk due to contact were submitted to epidemiological and clinical studies. From these individuals, 54 sera were analyzed by serological and molecular procedures. This study was conducted in Rio de Janeiro State from September 2002 to October 2006.
  
  
  RESULTS
  The clinical frequency of infection was 52.0%, with 57.4% ELISA and 43.0% PRNT-positive reactions. DNAemia was detected in 18.5% of the analyzed sera, and 50% of smallpox-vaccinated individuals developed symptoms.
  
  
  CONCLUSIONS
  This study confirms the high clinical frequency of human VACV infection, even among vaccinated individuals. The infection was related to detection of IgG- or IgM-specific antibodies that correlates in most of the cases with positive PRNT. The DNAemia suggests viremia during VACV natural infections. Our data indicate that patients vaccinated against smallpox may no longer be protected.
authors.affiliation: Laboratório de Sanidade Animal, Hospital Veterinário, Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, Brazil. fernandeserthal@gmail.com
authors.forename: André Tavares
authors.initials: AT
authors.lastname: Silva-Fernandes
authors.forename: Carlos Eurico Pires Ferreira
authors.initials: CE
authors.lastname: Travassos
authors.forename: Jaqueline Maria Siqueira
authors.initials: JM
authors.lastname: Ferreira
authors.forename: Jônatas Santos
authors.initials: JS
authors.lastname: Abrahão
authors.forename: Eliseu Soares de Oliveira
authors.initials: ES
authors.lastname: Rocha
authors.forename: Flávia
authors.initials: F
authors.lastname: Viana-Ferreira
authors.forename: João Rodrigues
authors.initials: JR
authors.lastname: dos Santos
authors.forename: Cláudio Antônio
authors.initials: CA
authors.lastname: Bonjardim
authors.forename: Paulo César Peregrino
authors.initials: PC
authors.lastname: Ferreira
authors.forename: Erna Geessien
authors.initials: EG
authors.lastname: Kroon
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001938:Brazil; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D004279:DNA, Viral / Q000097:blood; D004196:Disease Outbreaks; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008875:Middle Aged; D012424:Rural Population; D014615:Vaccinia / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary*; D014616:Vaccinia virus / Q000302:isolation & purification*; D055815:Young Adult; D015047:Zoonoses / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M