Hepatitis A, B, C
I am going to cover Hepatitis A, B, and C
HEPATITIS A is one of the world’s most prevalent viral infections,. In 2005 approximately 119 million individuals were infected with the Hepatitis A virus. Hepatitis A virus (HAV) survives in moderate temperatures and is the cause of about 50% of all reported cases of viral hepatitis in the United States. Since the introduction of an effective vaccine in 1995, HAV cases in the U.S. have decreased by about 92%. HAV is shed in the feces and the primary mode of transmission is by food contaminated with fecal matter. Other common modes of infection are via contaminated water, personal contact (e.g. living in the same household with a person who has the virus), kids at day care centers, sexual contact, and illicit drug use. Approximately 55% of cases do NOT have an identifiable risk factor.
Although HAV is most often a self-limiting disease of the liver, its clinical course can be severe leading to an estimated 34,000 deaths world-wide in 2005. Severity of the disease is strongly age-dependent. In kids younger than 6 years of age, approximately 70-95% of infections are asymptomatic. In adults, 70-95% of infections result in clinical illness. Depending on age, signs and symptoms of infection can include vomiting, nausea, diarrhea, jaundice, dark urine, fever, headache, weight loss, and abdominal pain. Peak infectivity can be present two weeks before and a least one week after a person develops symptoms. Typically, acute illness does not last > 2 months, with clinical symptoms and laboratory abnormalities “gone” after this period of time. Continued
In summary, Hepatitis A is self-limiting in most cases. Infection with HAV can induce lifelong immunity, which is identified by seroprevalence of antibodies against the Hepatitis A virus. In areas such as sub-Saharan Africa and other low income regions of the world, almost 100% of older children and adults have acquired immunity. Complications are more common in adults older that 50 years. If you have been exposed to this virus, or develop symptoms listed in yesterday’s blog, call your healthcare professional ASAP. For advice as to “Should you be vaccinated with one of the Hepatitis A vaccines”? -DISCUSSS WITH YOUR HEALTHCARE PROFESSIONAL.
Matheny SC et al. Am Fam Physician 2012;86(11):1027-1034. Hepatitis A: Clinical Manifestations and Management. Jeong S-H et al. Intervirology 2010;53:15-19. Hepatitis A virus: Host interactions, molecular epidemiology and evolution. Vaughan G et al. Genetics and Evolution21 (2014) 227-243. Long-term protective effects of hepatitis A vaccines, A systematic review. Ott JJ et al. Vaccine 31 (2012) 3-11.
HEPATITIS B. Hepatitis B is an infectious disease caused by the Hepatitis B virus (HBV). It is endemic in Asia, Africa, the Pacific islands, parts of southern Europe, and Latin America. In areas where this infection is endemic, the majority of patients acquire the virus in the perinatal period or early childhood. This occurs through so called “vertical transmission” (mother to child). By contrast, so called “ horizontal transmission”)- infected patient to non-infected person, is the primary route of infection in Western countries or where the infection is NOT endemic. In this situation, infection is acquired via exposure to body and blood fluids of infected individuals (e.g. sexual intercourse, sharing needles, non-sterile tattoo or acupuncture needles, razors, toothbrush). One CANNOT develop Hepatitis B infection by hugging, kissing, sharing utensils, holding hands, breastfeeding, and being in the “sneeze mist”. Healthcare workers in transfusion or dialysis jobs are at increased risk. as are individuals living with infected persons or people living in institutions.
It is estimated that about 1/3 of the world’s population (around 2 billion) has been infected with the Hepatitis B virus. In 2013, approximately 129 million NEW infections were diagnosed. Worldwide, there are about 260-400 million people chronically infected with HBV. Although the majority of patients with HBV do not develop hepatic complications, it is estimated that during the lifetime of these chronically infected patients, 15-40% may develop serious health sequelae from their infection with the Hepatitis B virus. 750,000-1 million people die every year from HBV related cirrhosis and or hepatocellular carcinoma (HCC).
Studies have conclusively shown that infection is closely linked to cancer development. In 2008, about 2 million newly diagnosed cancers (equivalent to 16% of the global incidence) were attributable to some infections agent (bacteria, viruses, parasites). In 2012, primary liver cancer was the 5th leading cancer in men and 9th in women. Due to late diagnoses and a high recurrence rate, HCC is the 2nd most common in men and the 6th in women. Depending on the country, 2-4 times as many men as women are diagnosed with HCC.
About 45% of the world population lives in areas of high endemicity. This includes many Asian and African countries. In China alone, 35-62% of the population have positive markers for HBV infection.
HEPATITIS C. Globally, an estimated 185 million persons have been infected with the hepatitis C virus (HCV). After adjusting for under-reporting and asymptomatic infections, the Centers for Disease Control (CDC) estimates about 21,870 new U.S. HCV infections occurred in 2012. Worldwide, there are approximately 3-4 million newly infected persons each year. There are now about 3.6 people in the U.S. with HCV, although this number may be “underestimated”. Between 75-85% of those individuals diagnosed with HCV are expected to progress to chronic liver disease.
The natural history of HCV is quite variable and most patients who acquire hepatitis C do not spontaneously clear the virus and develop chronic HCV infection. Chronic infection with the hepatitis C virus results in liver fibrosis, ultimately leading to cirrhosis in many individuals. Patients who develop cirrhosis are at further risk for such complicating events as ascites, hemorrhage from abnormal blood vessels resulting from cirrhosis, encephalopathy (brain damage from chronic cirrhosis), and hepatocellular carcinoma. Continued.
Populations at risk for acquiring HCV include 1. Those who received blood transfusions or blood products prior to routine screening for the hepatitis C virus, I.V. drug users, patients with body piercings-acupuncture- tattoos (lack of sterile conditions when acquired), intranasal cocaine users, healthcare workers, those involved in high-risk sexual behavior, and dialysis patients. It has also been reported that lower education, poverty, and residing in highly “deprived” areas are also risk factors for acquiring HCV. Acute HCV infections are infrequently diagnosed, as most patients are asymptomatic (70-80%). Onset of symptoms occurs 3-12 weeks after exposure. Symptoms may include anorexia, weakness, malaise and jaundice. Jaundice is not common, occurring in only 15-20% of acutely infected individuals. Fulminant liver failure is rare, and rarely occurs unless a person has concomitant chronic hepatitis B infection. Continued.
HCV infection is associated with slowly progressive, persistent liver inflammation, leading to development of cirrhosis in approximately 10-20% of patients over a 20-30 year period of HCV infection. Many people do not have any idea they have HCV cirrhosis until they have complications from end-stage liver disease. Overall, once cirrhosis has developed, there is a 1-5% risk of developing hepatocellular carcinoma (HCC). Obesity and diabetes are associated with an increased risk for HCC development in chronic hepatitis C patients. Continued.
“Baby boomers”, defined as people born between 1945 and 1965 are estimated to account for 75% of individuals infected with HCV. And, on average, “boomers” are five times more likely to be infected than any other age group in the overall U.S. population. In 2012 and 2013, CDC and U.S. Preventive Services Task Force addressed the high prevalence of HCV infection in “boomers” and recommended a one-time screening for the hepatitis C virus in people born between 1945 and 1965, regardless of their history of risk factors for infection. ASK YOUR HEALTH CARE PROFESSIONAL IF YOU SHOULD BE TESTED FOR THE HCV. CURRENT TREATMENTS FOR THIS DEADLY VIRUS HAVE IMPROVED DRAMATICALLY!!!!!!!