title: A sudden rise in viral load is infrequently associated with HIV-1 superinfection.
abstract: OBJECTIVE
  To investigate the association between an unexpected increase in the blood plasma HIV-1 viral load in chronically untreated HIV-infected patients and the occurrence of an HIV superinfection, we analyzed the HIV-1 quasispecies in plasma samples before and at peak level in 14 patients.
  
  
  RESULTS
  Phylogenetic analysis of HIV-1 env-V3 fragments showed that in 2 patients a superinfection had occurred: their dominant V3 population at the peak level clustered separately from the V3 sequences in a sample predating the peak level. The rapid rise in viral load could be attributed to upper respiratory tract infections or a vaccination in 4 patients, suggesting that even minor health problems can result in significantly increased HIV-1 replication. In most other patients, no minor or major medical condition accompanied the rise in HIV-1 viral load, implying that in these patients the viral load increase was probably associated with disease progression.
  
  
  CONCLUSIONS
  This study suggests that an unexpected rapid rise in the plasma HIV-1 viral load of untreated patients can infrequently be ascribed to an HIV-1 superinfection.
authors: Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Amsterdam, The Netherlands.
authors: Suzanne
authors: S
authors: Jurriaans
authors: Karolina
authors: K
authors: Kozaczynska
authors: Fokla
authors: F
authors: Zorgdrager
authors: Radjin
authors: R
authors: Steingrover
authors: Jan M
authors: JM
authors: Prins
authors: Antoinette C
authors: AC
authors: van der Kuyl
authors: Marion
authors: M
authors: Cornelissen
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D010802:Phylogeny; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015163:Superinfection; D019562:Viral Load