group 19 epidemiology number of people .pptx

Nursing

1. Hepatitis B ترنيم بكر محمد شاهين شهد ناصر سعدي البشابشة انس راتب عبد الله النوايسة تقوى شريف محمود الصرايرة تقى مطلب عمر طريف مجد الدين رائد سليمان قبج EPIDEMIOLOGY AND BIOSTATISTICS ASSIGNMEN Dr.Ahmad Alsagarat Group 19

2. Outlines 1. The disease 2. Epidemiology 3. Clinical features 4. Laboratory confirmation 5. Prevention 6. Surveillance

3. The disease Hepatitis B is an acute viral infection of the liver. Its public health importance lies in the severity of disease, its ability to cause long-term carriage leading eventually to cirrhosis and hepatocellular cancer, its transmissibility by the blood-borne route and the availability of vaccines and specific immunoglobulin.

4. Epidemiology Epidemiology The incidence of acute hepatitis B varies considerably across Europe. In most countries the incidence is low (less than 5 per 100,000), with a few notable exceptions, mainly in the Baltic States, where the incidence may be as high as 35 per 100,000 (see Table 3.31.1). The true incidence is higher, as about 70% of infections are subclinical and may not be detected. Most cases are in adults at high risk of infection (see Table 3.31.2), although horizontal transmission within families also occurs in the higher incidence countries. The carriage rate is below 1% in most countries, although there is considerable geographical variation within countries, with higher rates in inner cities amongst those of black and minority ethnic origin. Some ethnic groups have high rates of carriage, notably those from countries in south-east Asia and the Far East. The UK and Scandinavian countries have among the lowest rates of acute infection and carriage in the world.

5. Clinical features Not all people newly infected with HBV have symptoms, but for those that do They usually appear within a period of about one to six months after infection, but the patient may also feel them as early as the second week after infection. Symptoms can include fatigue, poor appetite, stomach pain, nausea, and jaundice. For many people, hepatitis B is a short-term illness. For others, it can become a long-term, chronic infection that can lead to serious, even life-threatening health issues like liver disease or liver cancer. Age plays a role in whether hepatitis B will become chronic:1.The younger a person is when infected with the hepatitis B virus, the greater the chance of developing chronic infection , The risk goes down as a child gets older. 2. adults infected with the hepatitis B virus recover completely and do not develop chronic infection.

6. Laboratory confirmation The laboratory diagnosis of infection requires the demonstration—either direct or indirect—of viral, bacterial, fungal, or parasitic agents in tissues, fluids, or excreta of the host. * The diagnosis and stage of infection can be determined from the antigen and antibody profile in the blood ex:- Confirmation of acute HAV is dependent upon demonstration of specific IgM antibodies, which are usually present at onset of symptoms and persist for around 3 months. IgG antibody persists for life and so in the absence of IgM, a fourfold rise in titers in paired samples is required for diagnosis, although patients rarely present in time for this to this to be demonstrable. Persistent IgG may be taken as evidence of immunity due to past infection (or vaccination). Salivary IgM (and IgG) testing is available at specialist laboratories and may be useful in outbreak investigations. HAV-RNA can be detected in blood and stool early in the infection.

7. Prevention Ensure that all blood and blood products are screened and not derived from donors at risk of infection. Adopt universal procedures for the prevention of blood-borne virus transmission in hospitals and all other situations where needles and other skin piercing equipment are used (e.g. acupuncture clinics, tattoo parlors ear/body-piercing). Prevent infected healthcare from performing exposure-prone procedures.

8. Cont ... Hepatitis B vaccination, of infants and/or older children, is recommended in most EU countries except for the UK and a few other countries, where selective vaccination is recommended only for high-risk groups The schedule is three injections at 0, 1 and 6 months. Where more rapid protection is required (e.g. for travelers or for post-exposure prophylaxis) this schedule can be accelerated to 0, 1 and 2 months (or to 0, 7 and 21 days), in which case a fourth dose should be given at 12 months. The vaccine should not be given in the buttock as efficacy may be reduced Protection is probably lifelong in a healthy adult who responds to the primary course. Healthcare workers and babies born to hepatitis B carrier mothers should, however, have their antibody status checked 4–6months after immunization. Poor responders (anti-HBs 10– 100mIU/mL) should receive booster dose and in non-responders (anti-HBs < 10 mIU /mL) a repeat course should be considered. Adults over 40 years of age and those with immunodeficiency are more likely to be non responders

9. Surveillance Acute hepatitis B is notifiable in most European countries. •Surveillance should ideally be based on laboratory reports, as the disease is clinically indistinguishable from other causes of viral hepatitis IgM and e antigen/antibody results should be included with notifications to facilitate public health action