Disease Project-Hepatitis B by Racheal Graham

Causative Agent

rachealgraham10 — 2023-11-03 11:01:27 UTC

Hepatitis B Virus (HBV)
Genus and Species: Orthohepadnavirus - Hepatitis B Virus
The virus is a small, enveloped, partially double-stranded DNA virus that replicates through an RNA intermediate

Mode of Transmission

rachealgraham10 — 2023-11-03 11:11:22 UTC

Modes of transmission include sexual contact, sharing needles, and mother-to-child transmission.

Symptoms of the Disease.

rachealgraham10 — 2023-11-03 11:54:41 UTC

Common symptoms include fatigue, jaundice, dark urine, and abdominal pain.

Most Important Virulence Factor.

rachealgraham10 — 2023-11-03 12:11:31 UTC

The most important virulence factor of HBV is the HBV X protein (HBx), which is a multifunctional protein that plays a critical role in the pathogenesis of HBV-associated liver diseases. HBx is involved in the regulation of viral replication, transcription, and translation, as well as the modulation of host cell signaling pathways and immune responses.

Diagnosis

rachealgraham10 — 2023-11-03 12:26:33 UTC

Visual representation of the diagnostic process, including blood tests and markers like HBsAg, anti-HBc, and viral load assessments.

Treatment.

rachealgraham10 — 2023-11-03 12:36:47 UTC

While the chronic form of the infection is not curable, it can be managed with medication and lifestyle changes. Tenofovir acts through different mechanisms, including the inhibition of viral polymerase-causing chain termination and the inhibition of viral synthesis. All these activities are attained by its competition with deoxyadenosine 5’-triphosphate in the generation of new viral DNA. Once Tenofovir is incorporated into the chain, it induces a chain termination, which in turn inhibits viral replication.

Sequelae.

rachealgraham10 — 2023-11-03 12:46:15 UTC

Chronic HBV infection can lead to the development of cirrhosis, liver failure, and liver cancer. Patients with chronic HBV infection are also at increased risk of developing other liver diseases, such as fatty liver disease and alcoholic liver disease

Prevention.

rachealgraham10 — 2023-11-03 12:59:03 UTC

The most effective way to prevent HBV infection is through vaccination.

The 1980s hepatitis B vaccine was created by Drs. Baruch Blumberg and Irving Millman. The FDA authorized “Heptavax” as the first commercial hepatitis B vaccine in 1981. Recombinant vaccinations superseded plasma-derived vaccines in 1986. Recombinant vaccines are synthetic and do not contain blood components, thus they cannot cause hepatitis B.

Epidemiology.

rachealgraham10 — 2023-11-03 13:09:34 UTC

According to the World Health Organization (WHO), approximately 296 million people worldwide are chronically infected with HBV, and an estimated 1.5 million people die each year from HBV-related liver disease. The highest prevalence of HBV infection is found in sub-Saharan Africa and East Asia, where up to 10% of the population is chronically infected.
US prevalence: Foreign-born Americans had a weighted average chronic hepatitis B prevalence of 3% in 2018. Most 2018 US chronic hepatitis B patients were from Asia (59%), the Americas (19%), and Africa (15%). Only 25% of sick people are diagnosed.

References

rachealgraham10 — 2023-11-03 13:11:40 UTC

Lok, A. S. F., McMahon, B. J. (2007). Chronic hepatitis B. Hepatology, 45(2), 507-539.
World Health Organization (WHO). (2021). Hepatitis B. https://www.who.int/news-room/fact-sheets/detail/hepatitis-b
CDC. (2021). Hepatitis B. Centers for Disease Control and Prevention. https://www.cdc.gov/hepatitis/statistics/index.htm