1. PREVENTION OF HEPATITIS B VIRUS INFECTION & SCREENING OF HEPATOCELLULAR CARCINOMA [HCC] BY DR. AGUNYENWA, C.

2. REVIEW OF TRANSMISSION OF HEPATITIS B VIRUS INFECTION  Routes of transmission –Transfusion of unscreened blood & blood products –Sexual contact –Baby’s contact with mother’s blood or secretions during labour –Needle stick injury –Use of unsterile needles, instruments for tatooing, scarifications, circumcision etc.

3. REVIEW OF TRANSMISSION OF HEPATITIS B VIRUS INFECTION –Non observance of universal precautions in the handling of body secretions and fluids. –Other modes:  Sharing of bath towels, chewing gums, partially eaten candies, dental cleaning materials.  Biting of finger nails after scratching the back of carriers.

4. Facts to remember about HCC  The most common hepatic cancer  One of the ten most common carcinomas in the world.  In Taiwan and Nigeria, prevalence is so high that it is the most common cause of death due to malignancy in males  Closely associated with HBV & HCV infections.

5. Prevention of HBV infection: Adequate screening of blood and blood productsAdequate screening of blood and blood products Use of sterile needles and sharp objects/instrumentsUse of sterile needles and sharp objects/instruments Avoidance of sexual promiscuity.Avoidance of sexual promiscuity. Avoidance of needle stick injuryAvoidance of needle stick injury Observance of universal precautions in handling of body secretions and fluidsObservance of universal precautions in handling of body secretions and fluids Discouragement of children from sharing of towels, partially eaten candies or tooth brushes, biting of their fingers.Discouragement of children from sharing of towels, partially eaten candies or tooth brushes, biting of their fingers. Passive immuno-prophylaxisPassive immuno-prophylaxis ImmunisationImmunisation

6. HB vaccine Types of HB vaccines:Types of HB vaccines: –Plasma derived [heptavax ® ] –Biogenetically engineeered [engerix B ®, Genhevac ® ]  Important characteristic of HB vaccines: –Stability over a wide range of temperature

7. HB vaccine  WHO recommendation:  For children –3 doses –Co-administered with other vaccines –1 st dose – as early as possible where perinatal transmission is common  Additional protection may be provided by administration of immune globulin at birth –2 nd dose – within 2 months –3 rd dose – within 1 st year

8. HB vaccine Age Example 1 Example 2 Birth BCG/OPV/HB V BCG/OPV 6 wks DPT/OPV/HBVDPT/OPV/HBV 10 wks DPT/OPV DPT/OPV/HBV 14 wks DPT/OPVDPT/OPV 6 – 12 months MEASLES/HB V

9. HB vaccine  Adults –Unvaccinated with needle stick injury:  HB immune globulin – 0.06 ml/kg i.m  HB vaccine - 1ml (0,1,6 months) or (0,1,2,12months)  Vaccinated with needle stick injury: –Check for anti-HBsAg –If adequate – no treatment otherwise give a booster dose of HB vaccine.

10. SCREENING FOR HEPATOCELLULAR CARCINOMA  The incidence of hepatocellular carcinoma (HCC) has increased dramatically within recent decades.  Factors responsible: –the epidemic of HBV & HCV infection, as well as cirrhosis from diverse etiologies.  Patients with cirrhosis have a 1 – 6% annual risk of developing HCC. 1 – 6% annual risk of developing HCC.

11.  Usually it can be treated successfully with liver transplantation, partial hepatectomy or ablation when there is – single tumour less than 5cm –or no more than three tumours less than 3cm and the disease is intrahepatic.  Why screening for HCC? –Many patients with HCC are not diagnosed until the disease is advanced and not treatable,  the median survival time after diagnosis is 6-20 months.  Therefore, there is a considerable interest in screening high risk patients for HCC in order to detect early stage disease that is a amenable to treatment.

12.  However, at this time there is no good evidence to show that early detection increases long-term survival.  Screening Methods  Screening for HCC is most commonly conducted every 6 – 12 months in patients at risk by measuring the serum concentration of the – Alpha fetroprotein (AFP) and – ultrasonography  Alpha Fetoprotein The sensitivity and specificity of AFP screening varies with the level of AFP. The sensitivity and specificity of AFP screening varies with the level of AFP.

13.  Overall neither the sensitivity nor the specificity is high and the predictive value varies from 9-50%. i.e Levels > 500mcg/L are found in about 70 – 80% patients with HCC. Limitations of AFP  Normal in 20 – 30% of patients with HCC especially the fibrolamella type.  Elevated in pregnancy, Tumours of gonadal origin, some cases of acute or chronic hepatitis without a tumour, Metastasis from gastric or colonic tumours.

14.  Ultrasonography (USS) –Sensitivity of 20 – 58% –Specificity of 92 – 96%.  Limitations of (USS) -Sensitivity depends on the build of the patient. Slim individuals – higher sensitivity and vice versa. Slim individuals – higher sensitivity and vice versa. - Mitotic lesions on background of cirrhosis are poorly detected. - Although, USS is the least sensitive of the imaging modalities for the detection of HCC compared to CT and MRI, constraints of cost and resource availability have made CT and MRI unsuitable as routine screening method.

15.  Therefore, USS should be the initial screening method together with monitoring serum concentration of AFP.  Contrast enhanced MRI or CT scan is recommended for further evaluation of the patient if: –the ultrasound images are abnormal either because the liver has a heteregenous appearance due to cirrhosis –or because a lesion is detected by ultrasound.