A report published in the Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report said among the 25 patients investigated medical records of 21 were reviewed, 17 patients were interviewed and 16 provided blood samples for quasispecies analysis to assess relatedness of their hepatitis C virus.
"Of the 25 patients, 28 percent had symptoms of jaundice, consistent with acute hepatitis C virus infection. All 25 patients had antibodies to hepatitis C virus by enzyme immunoassay," the report said. "Ninety-four percent of 17 interviewed patients admitted to sharing hypodermic needles, drug preparation equipment, or drug snorting equipment. Ninety-four percent of 17 interviewed patients admitted to either injecting drugs [12 patients], snorting illicit drugs [16 patients], or both [12 patients]."
Three of eight patients who reported injecting opioid pain relievers started injecting prescription opioids and switched to injecting heroin or methamphetamine after a median of three years, the report said.
"Six specimens could be analyzed at the CDC for variations and four of them were genetically similar in that region," the report said. "These underwent quasispecies analysis but were unrelated, suggesting that patients were infected through unrelated networks of hepatitis C virus transmission and that many other undetected cases might also exist."