A study on the long-term infectiousness of the hepatitis C virus (HCV) has implications for healthcare workers, IV drug users, and tattoo artists, while another study shows the benefits of coffee and tea on liver inflammation in chronic hepatitis C patients.
Dried HCV remains infective for weeks
Research out of the Yale School of Medicine shows that HCV in dried droplets of blood or plasma can remain infectious for up to six weeks. The study, reported in the November, 23, 2013 edition of the Journal of Infectious Diseases, has implications for healthcare settings and any situations where HCV may be present.
It’s already well known that HCV is easily transmitted through direct contact with blood, through an accidental needle stick or syringe-sharing among IV drug users. Until now it has not been well known about how long the virus can remain infectious on surfaces, when the surface containing the virus is dry.
Elijah Paintsil from the Yale School of Medicine and colleagues wanted to find out exactly how long the virus may be viable on surfaces that have come into contact with blood or other body fluids containing HCV. They simulated real-life situations and looked at “formites,” or surfaces like hair, clothing, bedding, and stethoscopes that can transmit the virus.
The researchers determined the volume of misplaced drops during transfer of serum or plasma, as may occur during healthcare procedures such as placing venous lines. Next, they added a genetically engineered genotype 2a HCV “reporter virus” to samples of the same volume, placed them on 24 plates, and allowed them to dry out uncovered at temperatures of 4° C (refrigerator temperature), 22° C (room temperature), and 37° C (body temperature) for up to 6 weeks.
• At storage temperatures of 4° and 22° C, viable HCV was recovered from low titer spots after up to six weeks.
• At 37° C, infectious HCV was recovered only up to seven days.
• HCV infectivity declined rapidly during the first two weeks of storage, followed by a slower decline.
• A 1:10 dilution of bleach was highly effective in reducing HCV infectivity, with 1 minute of exposure eliminating infectious HCV in 100-percent of spots. Commercial medical disinfectants were somewhat less effective than bleach, and their effectiveness varied.
Their findings have implications for a variety of settings where HCV may be present, because, they conclude that spots contaminated with HCV dried at room air within four hours, “becoming inconspicuous and therefore more likely to cause accidental exposures to HCV.”
Paintsil and colleagues previously reported that HCV can survive in syringes for up to two months under certain conditions.
Coffee, Tea & HCV
There’s another study showing a beneficial link between coffeee, tea, or other caffeine-containing products and liver health. The latest study, published in the December 11, 2013 edition of PLoS ONE, finds that filtered, caffeinated coffee and black or oolong tea consumed on a daily basis can be beneficial for reducing liver inflammation in chronic hepatitis C patients.
Yachiyo Sasaki and colleagues from Osaka City University in Japan looked at the effect of coffee and tea consumption on alanine aminotransferase (ALT) levels over twelve months among adults with chronic hepatitis C. ALT levels are indicators of liver damage from different types of disease, (although higher-than-normal levels of these liver enzymes should not be automatically equated with liver disease).
They followed 376 patients with detectable HCV in a hospital-based cohort study. Sixty percent were women and the mean age was approximately sixty-five years, and people who started interferon-based therapy were excluded. About sixty percent had normal ALT at baseline while the rest had elevated ALT. About half never drank caffeinated filtered coffee and the remainder were divided between those who drank less than 1 cup per day and those who drank 1 cup or more daily.
• Among 229 participants with normal ALT at baseline, eighty-one percent still had normal ALT levels twelve months after recruitment, suggesting that HCV was less likely to cause further liver damage.
• People who drank filtered caffeinated coffee daily were three times more likely to maintain normal ALT than those who did not drink filtered coffee.
• Among 147 patients with higher ALT levels at baseline, twenty-seven percent experienced ALT reductions of at least 20 IU/L by twelve months after recruitment.
• People who drank filtered coffee had a significantly increased likelihood of ALT reduction.
• No participants who drank decaffeinated experienced ALT reduction.
• People who drank four or more cups of black or oolong tea had a greater likelihood of having normal ALT than those who drank less.
“To the best of our knowledge, this is the first study to report a favorable association between consumption of black tea/oolong tea and serum ALT level,” the authors added.
Larry Buhl is a radio news reporter, screenwriter, and novelist living in Los Angeles. His young adult novel, The Genius of Little Things, debuted in January 2013.