Most baby boomers infected in hospital and by reused medical syringes, not injecting drug use or risky sex
The spread of hepatitis C virus (HCV) in North America peaked between 1940 and 1965, according to research published in Lancet Infectious Diseases. The investigators attribute the rapid spread of the infection to hospital transmissions and reuse of medical injecting equipment rather than risky behaviours such as injecting drugs, unsafe tattooing and unprotected sex.
“Based on our results, the oldest members of the demographic cohort with the highest burden of hepatitis C virus (the baby boomers) were roughly five years of age around the peak of the spreads of genotype 1a in North America in 1950,” comment the authors. “Thus, it is unlikely that past sporadic risky behaviour (experimentation with injecting drug use, unsafe tattooing, high risk sex, travel to endemic areas) was the dominant route of transmission in this group.” The researchers hope their findings will help de-stigmatise HCV infection in the baby boomer generation and encourage more patients to access testing and potentially life-saving treatment.
Up to 6 million individuals in North America are infected with HCV. Approximately three-quarters of these infections involve patients born between 1945 and 1965, the baby boomer generation. Previous studies have identified infected blood products and experimentation with injecting drug use as the main factors driving the spread of HCV in this age group.
However, how and when HCV reached such high prevalence in the 1945-65 birth cohort remains unclear. A team of investigators therefore analysed 45,316 sequences of HCV genotype 1a – by far the most common HCV strain in North America. Using a technique called phylogenetic analysis they focused on five HCV genes to reconstruct the dynamics of the HCV epidemic in North America.