title: Intrafamilial transmission of HIV-1 infection from individuals with unrecognized HIV-1 infection.
abstract: OBJECTIVE
  To describe the clinical, epidemiological and molecular evidence for transmission of HIV-1 infection from a person with unrecognized HIV infection to a family member in two unconnected families where the route of transmission could not be conclusively determined.
  
  
  METHODS
  Case studies, molecular analysis of viral strains and a clinical and laboratory investigation of risk factors for transmission.
  
  
  METHODS
  State referral centres for HIV/AIDS in two Australian teaching hospitals.
  
  
  RESULTS
  Previously unrecognized HIV-1 infection was diagnosed in two unconnected females following blood donation in different Australian cities. Initially, no source of infection was identified but subsequently HIV-1 infection was diagnosed in the sister of one case and the adult son of the other. Using nucleic acid-based methods, it was demonstrated that one index case and her sister were infected with highly homologous 'Russian-type' HIV-1 subtype A, and the other index case and her son were infected with highly homologous HIV-1 subtype E (CRF01_AE). Sexual history taking from the sister and the son of the respective index cases revealed prior sexual partners from geographical areas in which the corresponding subtypes are known to be prevalent. Extensive history taking, cross-validated by independent reviewers, found no evidence whatsoever that any form of sexual contact or known blood contact could explain the HIV-1 infection in the two index cases. However, there was evidence that some form of domestic contact involving unperceived blood transfer may have occurred.
  
  
  CONCLUSIONS
  Intra-familial transmission of HIV-1 infection should be considered when a source of HIV-1 infection cannot be determined.
authors.affiliation: Department of Clinical Immunology and Biochemical Genetics, Royal Perth Hospital, Australia.
authors.forename: Martyn A
authors.initials: MA
authors.lastname: French
authors.forename: Belinda L
authors.initials: BL
authors.lastname: Herring
authors.forename: John M
authors.initials: JM
authors.lastname: Kaldor
authors.forename: David C
authors.initials: DC
authors.lastname: Sayer
authors.forename: Virginia
authors.initials: V
authors.lastname: Furner
authors.forename: Christian C
authors.initials: CC
authors.lastname: de Chaneet
authors.forename: Dominic E
authors.initials: DE
authors.lastname: Dwyer
mesh_terms: D000293:Adolescent; D018562:Disease Transmission, Infectious; D005192:Family Health; D005260:Female; D015699:HIV Envelope Protein gp120 / Q000235:genetics; D015658:HIV Infections / Q000635:transmission* / Q000821:virology; D015497:HIV-1 / Q000145:classification; D020180:Heteroduplex Analysis; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008875:Middle Aged; D010802:Phylogeny; D017385:Sequence Homology
chemical_list: D015699:HIV Envelope Protein gp120