Hepatitis C virus epidemiology Varsha Shete [email protected] Jeni [email protected].
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Transcript of Hepatitis C virus epidemiology Varsha Shete [email protected] Jeni [email protected].
Discovery
Hepatitis C was discovered in the
1988
Original name was non-A, non-B
Hepatitis virus
Hepatitis C antibody test made
available in 1990
1995 marked first sight under
electron microscopy
Basics
Flaviviridae Linear + Sense SS RNA Genome around10,000 bases Enveloped Spherical 40-50 nm Replicates in cytoplasm
HCV IRES
Secondary structure:
stem-loop structure
No cap
5’ untranslated region
of HCV shown here
AUG start codon
shown here
Distribution
Deaths due to associated cirrhosis in the United States 10-20K
4% develop chronic hepatitis C
Only 20% of infected people develop symptoms
Prevalence
Found to be prevalent in incarcerated adults (as high as 80%) More common in developing nations
Shepard et al
CountryEstimated 2004 total population (millions)
Estimated HCV seroprevalence (%)
Population studied
China 1300 3·2Nationally representative sample (n=68 000)
India 1087 0·9Community-based, West Bengal (n=3579)
USA 294 1·8Nationally representative sample (n=21 214)
Indonesia 219 2·1Volunteer blood donors (n=7572)
Brazil 179 1·1Volunteer blood donors (n=66 414)
Pakistan 159 4·0Volunteer blood donors (n=103 858)
Transmission
Blood and body fluids
Intravenous drug users
Blood or organ donation
before1992 or clotting factors
before 1987
Unsterile body art / modification
Sexual promiscuity
Mother to child
Other Factors
Other cofactors are: male sex older age at acquisition of HCV infection HIV co-infection hepatitis B virus (HBV) co-infection alcohol consumption
HIV and HCV co-infection causes severe liver damage and further lowers the chances of survival
Symptoms and Duration
Major cause of liver failure Fever Loss of appetite Nausea Abdominal pain Dark colored urine Clay-colored bowel Joint pain Jaundice Fatigue
10 yrs Chronic hepatitis 20 yrs Cirrhosis 30 yrs Hepatocellular carcinoma
Incidents and trends of infection (Epidemics) Impractical to measure infection incidents
Center for Disease Control and Prevention (CDC) in USA uses mathematical model for estimation of trends of infection
Age-specific reported cases of acute disease and data from a cross-sectional national survey done from 1988 to 1994 was used by CDC
The general observation was steady rise in the cases of HCV infection since the 1980’s
Incidents and trends of infection (continued)…
USA: steady and sharp drop through 1990’s
France: death rates from hepatocellular carcinoma was used as a model and similar trend was observed
Australia: steady increase from 1961 through 2001
Italy: decline in 1990’s
Russia: dramatic increase since 1994
England: clear decline after reduction of use of syringes and alternative drug therapy
Treatment
No vaccine and no completely effective
treatment! But pharmaceutical and medical
research companies are working on a variety of
possible new treatments
Belgian biotech firm Innogenetics is developing
a hepatitis C vaccine that may be able to halt or
reverse liver damage in people infected with the
disease, BBC News reported on 11/04/02
Treatment (continued)…
Interferon α
Patients inject interferon 2-3 times a week
25% of patients have good results with interferon
Doctors will discontinue after 3 months if there isn’t
a change with interferon and use the Rebetron.
Infergen (derivative of Interferon α)
Rebetron (Interferon + ribavirin)
References
“Global epidemiology of hepatitis C virus infection”, Shepard W, Finelli L, Alter M, The Lancet infectious diseases, Vol 5 (9) September 2005, 558-567
“Seroprevalence of hepatitis C among a juvenile detention population”, Feldman G, Sorvillo F, Cole B, Lawrence W, Mares R, Journal of Adolescent health Vol 35 (6), December 2004, 505-508
“Hepatitis B virus (HBV) and hepatitis C virus (HCV) infection epidemiology in Moscow region during 1995–1999” Isakov V, Tsodikov G, Ivanikov I, Kaira A, Seliverstova A, Shakhovski Y Journal of Hepatology, Vol 34 (11), April 2001, 191
www.who.org http://www.ncbi.nlm.nih.gov/ICTVdb http://virology-online.com/viruses/HepatitisC.htm http://www.virology.net/Big_Virology/BVRNAflavi.html http://www.hepnet.com/hepc.html#history http://www.aafp.org/fpr/20031100/27.html http://www.cnn.com/HEALTH/9703/26/nfm/hepatitis.c/index.html