title: Detection of hepatitis B virus genotype A3 and primary drug resistance mutations in African immigrants with chronic hepatitis B in Spain.
abstract: BACKGROUND
  Universal vaccination and antiviral therapy have reduced chronic hepatitis B virus (HBV) in natives in the Western world. However, immigration from high HBV endemic areas continues to maintain a relatively stable prevalence of chronic hepatitis B in most developed countries.
  
  
  METHODS
  All foreigners attending a referral infectious diseases department in Madrid, Spain, from January 2007 to December 2008, were evaluated for serum HBV surface antigen (HBsAg). Positive cases underwent further virological characterization.
  
  
  RESULTS
  A total of 1718 foreigners were examined, of whom 1322 (77%) were sub-Saharan Africans. Serum HBsAg was positive in 121 (7%), HIV in 135 (7.9%) and hepatitis C virus antibodies in 212 (12.3%). HBV subgenotype A3, which so far had only been reported in people originating from Cameroon, was found in nearly half (14/29) of the tested specimens with detectable serum HBV-DNA. Interestingly, the lamivudine resistance mutation rtM204V was found in two Africans (6.9%), one infected with HBV-A3 and the other with HBV-E. Lack of prior exposure to antiviral therapy in these two patients was confirmed retrospectively.
  
  
  CONCLUSIONS
  Circulation of uncommon HBV variants, including strains with primary drug resistance, may follow large immigrant flows from HBV endemic regions to Western countries. Close surveillance of this population is warranted, as early diagnosis and early antiviral therapy may reduce transmission and prevent clinical complications.
authors.affiliation: Infectious Diseases Department, Hospital Carlos III, Madrid, Spain.
authors.forename: Marcelle
authors.initials: M
authors.lastname: Bottecchia
authors.forename: Antonio
authors.initials: A
authors.lastname: Madejón
authors.forename: Sabino
authors.initials: S
authors.lastname: Puente
authors.forename: Javier
authors.initials: J
authors.lastname: García-Samaniego
authors.forename: Pablo
authors.initials: P
authors.lastname: Rivas
authors.forename: Dolores
authors.initials: D
authors.lastname: Herrero
authors.forename: Vincent
authors.initials: V
authors.lastname: Soriano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D024882:Drug Resistance, Viral; D054242:Emigrants and Immigrants; D005260:Female; D005838:Genotype; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D019694:Hepatitis B, Chronic / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D013030:Spain; D055815:Young Adult
chemical_list: D006514:Hepatitis B Surface Antigens