### Microbiology
A virus. There are a variety of genotypes: C progresses faster.
### Epidemiologic Risks
Exposure to contaminated blood. So, if you are sharing needles as part of your heroin use, might I suggest it is a suboptimal idea. Sex. And maybe maybe maybe sweat. [^1] Now whatcha gonna do at the gym with that sweaty barbell?
> "One-fifth of adults with IDU histories had a previous or ongoing HBV infection: a rate over 4 times higher than the prevalence in the general population." [^2]
Reactivates with rituximab and ofatumumab (anti CD20); check [[Hepatitis B]] status before starting.
### Syndromes
[[Hepatitis]] (acute and chronic), cirrhosis and hepatic cancer. Can get a 'flair' reaction with e seroconversion.
There are too numerous to count articles on what to make of [[Hepatitis B]] serologies. I will not repeat it here.
### Treatment
I have never treated the disease, there are guidelines. Look them up and follow them.
Treat if ALT 2x normal and e antigen-positive and elevated (>20,000) DNA. If ALT up and DHA < 20,000, look for another reason for increased ALT. All cirrhotics should be treated if any viral load.
Entecavir is approved for chronic [[Hepatitis B]], but it breeds resistance in [[HIV]]. [^3]
or
[[Tenofovir]]. Maybe the better of the two. The [[Tenofovir]] alafenamide form is less toxic (bone and kidney} but more expensive.
**Prophylaxis**
Chemotherapy and immunosuppression can lead to reactivation/flair.
Check surface antigen, core antibody, and anti-surface antigen.
Positive DNA < 20,000 needs prophylaxis.
Reactivation with surface antigen-positive is 50%; the big risk is stem cell transplant, B cell depleting therapy, anthracycline medications and long term (> 4 weeks) steroids and needs prophylaxis.
### Notes
There is a [[Vaccine]]. It is very effective and good for at least 30 years. However, in HCW's who do not respond to the initial series do not get a better response with more jabs.
> "Discontinuation of [[Tenofovir]] disoproxil fumarate treatment rather than Entecavir treatment is associated with earlier relapse ..." [^4]
Chronic [[Hepatitis B]] infection increases the risk of colorectal liver metastasis. Odd. [^5]
Chronic [[Hepatitis B]] increases the risk of death with acute [[Hepatitis E]]. [^6]
While treatment will cause cirrhosis to regress, there is still a risk for cancer and the patient still needs q 6-month screening.
### Rationalizations
[^1]: Bereket-Yücel S. Risk of [[Hepatitis B]] infections in Olympic wrestling. Br J Sports Med. 2007 May;41(5):306-10; discussion 310. doi: 10.1136/bjsm.2006.032847. Epub 2007 Mar 1. PMID: 17331974; PMCID: PMC2659063.
[^2]: Shing JZ, Ly KN, Xing J, Teshale EH, Jiles RB. Prevalence of [[Hepatitis B]] Virus Infection Among US Adults Aged 20-59 Years With a History of Injection Drug Use: National Health and Nutrition Examination Survey, 2001-2016. Clin Infect Dis. 2020 Jun 10;70(12):2619-2627. doi: 10.1093/cid/ciz669. PMID: 31350875; PMCID: PMC7286375.
[^3]: McMahon MA, Jilek BL, Brennan TP, Shen L, Zhou Y, Wind-Rotolo M, Xing S, Bhat S, Hale B, Hegarty R, Chong CR, Liu JO, Siliciano RF, Thio CL. The HBV drug Entecavir - effects on [[HIV]]-1 replication and resistance. N Engl J Med. 2007 Jun 21;356(25):2614-21. doi: 10.1056/NEJMoa067710. PMID: 17582071; PMCID: PMC3069686.
[^4]: Su TH, Yang HC, Tseng TC, Liou JM, Liu CH, Chen CL, Chen PJ, Chen DS, Liu CJ, Kao JH. Distinct Relapse Rates and Risk Predictors After Discontinuing [[Tenofovir]] and Entecavir Therapy. J Infect Dis. 2018 Mar 28;217(8):1193-1201. doi: 10.1093/infdis/jix690. PMID: 29300980.
[^5]: Tingting Huo, Jingyu Cao, Yaowen Tian, Xuetao Shi, Liqun Wu, Mingzhi Zhang, Linda L Wong, Lei Zhao, Effect of Concomitant Positive [[Hepatitis B]] Surface Antigen on the Risk of Liver Metastasis: A Retrospective Clinical Study of 4033 Consecutive Cases of Newly Diagnosed Colorectal Cancer, _Clinical Infectious Diseases_, Volume 66, Issue 12, 15 June 2018, Pages 1948–1952, [https://doi.org/10.1093/cid/cix1118](https://doi.org/10.1093/cid/cix1118)
[^6]: Lai JC, Wong GL, Yip TC, Tse YK, Lam KL, Lui GC, Chan HL, Wong VW. Chronic [[Hepatitis B]] Increases Liver-Related Mortality of Patients With Acute [[Hepatitis E]]: A Territorywide Cohort Study From 2000 to 2016. Clin Infect Dis. 2018 Sep 28;67(8):1278-1284. doi: 10.1093/cid/ciy234. PMID: 30265321.