A new study finds hepatitis C virus (HCV) infection to be associated with a 70% increased rate of mortality in in-hospital patients with invasive pneumococcal disease (IPD).
According to the World Health Organization (WHO), between 55% and 85% of individuals infected with the hepatitis C virus (HCV)—which can be transmitted through infected needles or unscreened blood products—will develop a chronic infection. Patients with chronic HCV are at risk of developing liver cirrhosis and liver cancer. It is well-documented that patients with HCV and other concurrent infections, such as HIV, have faster rates of HCV disease progression. In a new study, published in the Centers for Disease Control and Prevention’s (CDC) Emerging Infectious Disease (EID) journal, lead investigator Dean Eurich, PhD, from the University of Alberta, and his colleagues examine the effects of concurrent infections with HCV and the bacterial infection caused by Streptococcus pneumoniae.
Streptococcus pneumoniae is a gram-positive bacterium that causes pneumococcal disease which can lead to infection of the lungs as well as bacteremia. Infection with the bacterium can often lead to invasive pneumococcal disease (IPD), as well. Professor Eurich and his colleagues hypothesized that IPD patients who are concurrently infected with HCV will be at higher risk of developing complications of the disease, thus leading to higher rates of mortality.
The researchers obtained data for patients with IPD, aged 17 years and older in northern Alberta, Canada, from 2000 to 2014. During the 15 years of this study, over 3000 patients with IPD were identified, of which 11% had concurrent HCV infections. The patients who were infected with IPD were “compared with IPD patients not infected with HCV for risk of in-hospital deaths and complications by using multivariable logistic regression.”
The authors report higher mortality rates for those with concurrent HCV infections in comparison to those with only IPD (16% vs 15%). Although there is only a difference of one percentage point, the authors note that this is a statistically significant difference. After adjusting for various variables, the authors show that in IPD patients concurrently infected with HCV, there is a 70% increased chance of mortality.
In addition to an increased rate of mortality, the authors found that risk of developing IPD-related complications, such as liver failure and acute kidney injury, were higher in patients co-infected with HCV. However, the authors note that risk of developing meningitis was significantly decreased in those infected with HCV.
Those HCV-infected patients “had a mean age that was 10 years younger than that for persons without HCV infections (P<.001). In addition, these patients “were significantly (all P < .001) ore likely to be Aboriginal, homeless, have concomitant HIV infection and cirrhosis of the liver, have alcoholism, and be current smokers and illicit drug users.”
The strengths of this study lie in the fact that a large number of IPD patients were examined over the course of 15 years. The authors do note several limitations, including the inability to classify stages of liver disease, only identifying HCV-positive individuals by a positive antibody test, as well as the lack of information on the vaccination status of patients. However, the authors have demonstrated that in those with IPD and concurrent HCV infections, the rate of mortality as well as the risk of developing more complications (except meningitis) is significantly heightened.
Samar Mahmoud graduated from Drew University in 2011 with a BA in Biochemistry and Molecular Biology. After two years of working in industry as a Quality Control Technician for a blood bank, she went back to school and graduated from Montclair State University in 2016 with an MS in Pharmaceutical Biochemistry. She is currently pursuing her PhD in Molecular and Cellular Biology at the University of Massachusetts at Amherst.