10- Sexually transmitted disease (viral) Flashcards
HPV
human paipilloma virus
- most common viral STI
- >100 strains
- 90% Type 6 and 11 ( cause external genital warts)- least harmful
- high risk HPV for neoplastic changes 16+18
HPV strain with highest risk of neoplastic change
16 and 18
pathophysiology of HPV
MOA of HPV
- sexual contact
- incubation period 2 weeks to 8 months
what do not give protection from HPV genital warts
condoms- skin to skin contact
HPV presentation
- multifocal infection of anogenital skin
- usually painless/ itchy
- psychological disress
- post sexual contact
tecture of HPV warts
internal HPV warts
DD for HPV warts
Buschke- Lowenstein
rare sexually transmitted disease caused by human papilloma virus infection in the anogenital area.
-Giant condyloms accuminata
- higher rate of malignant transformation than genital warts
Management of HPV
- screen for other STIs
- treatment largely aimed at getting rid of the appearanc eof warts but will not clear the virus, body clears over time
HPV counselling to prevent significant psychological distress
- often clears spontaeneously
- strains which cause warts dont generally cause cancer
- condoms may prevent transmission
HPV and patient applied therapy
more successful on softer warts
self applied over 4 weeks and then review
treatments include
- podophyllotoxin
- imiquimod
- catephen
podophyllotoxin
- antimitotic agent
- inhibits cell division
imiquimod
- immune response modifier- not directly anti-viral
- stimulates innate and acquired immune response
catephen
freen rea leaf extract
MOA unknown but effect vs placebo in trial
referral and HPV
have a low threshold to refer
national HPV immunisation england
quadrivalent vaccine: subtypes 6, 11, 16, 18
started in 2008- girls only
2018- MSM <45
2019- boys too
HPV and pregnancy
- common for warts to present for the first time during pregnancy
- linked to altered immune response
- difficult to treat - home treatment teratogenic
- HOWEVER risk of vertical transmission very low (shpuldnt influence mode of dleivery)
**management
- watch and wait
- cryoablation
- srufical removal for extreme cases
HPV and risk to baby
- 4/100,000 risk of **respiratory laryngeal papillomatosis
- tiny risk of obstruction to delivery
true false fact sheet about HPV
herpes simplex virus (HSV)
responsible for both cold sores (herpes labialis) and genital herpes
- many people have np symptoms
main strains of HSV
HSV-1
HSV-2
pathophysiology of HSV latency
- After an initial infection, the virus becomes latent in the associated sensory nerve ganglia.
- Typically this is the trigeminal nerve ganglion with cold sores and the sacral nerve ganglia with genital herpes.
other areas affected by HSV
- cause aphthous ulcers (small painful oral sores in the mouth)
- herpes keratitis (inflammation of the cornea in the eye) and
- herpetic whitlow (a painful skin lesion on a finger or thumb).
HSV mode of transmission
direct contact with affected mucous membranes or vrial sheeding in mucous secretions
- can be spread by asymptomatic (more common in first 12 months where recurrent symptoms present)
HSV-1
cold sores
It is often contracted initially in childhood (before five years), remains dormant in the trigeminal nerve ganglion and reactivates as cold sores, particularly in times of stress.
- can cause herpes in genitalia through oral sex
HSV-2
Genital herpes caused by HSV-1 is usually contracted through oro-genital sex, where the virus spreads from a person with an oral infection to the person that develops a genital infection.
presentation of genital herpes
incubation- 2 weeks
- asymptomatic
- initial presentation most severe
* Ulcers or blistering lesions affecting the genital area
* Neuropathic type pain (tingling, burning or shooting)
* Flu-like symptoms (e.g. fatigue and headaches)
* Dysuria (painful urination)
* Inguinal lymphadenopathy
-> symptoms can last for 3 weeks in primary infection
diagnosis of herpes
Ask about sexual contacts, including those with cold sores, to establish a possible source of transmission. They may have caught the infection from someone unaware they are infected and not experiencing any symptoms.
The diagnosis can be made clinically based on the history and examination findings.
A viral PCR swab from a lesion can confirm the diagnosis and causative organism.
managment of herpes
antiviral: aciclovir
additional measures
- paracetamol
- topical lidocaine 2% gel (instillagel)
- cleaning with warm salt water- key prevents secondary bacterial infection and drys up lesion
- topical vaseline
- additional oral fluid
- loose clothing
- avoid intercourse with symptoms
pregnancy and genital herpes
not related to pregnancy related issues or congenital abdnormalities.
- women can pass antibodies to the fetus to give passive immunity
- main risk: neonatal herpes simplex infection contracted during labour and delivery
neonatal herpes simplex infection
high rate of morbidity and mortality
- should be avoided and treated early
management of herpes during pregnancy
depends on scenario
1) primary genital herpes before 28 weeks gestation
2) primary genital herpes after 28 weeks
primary genital herpes before 28 weeks gestation
treatment:
- aciclovir during initial infection
- prophylactic aciclovir starting from 36 weeks to reduce risk of genital lesion during labour and delivery
- women who are asymptomatic at delivery can have a vaginal delivery
- woemn who are symptomatic should have a caesarean
primary genital herpes contracted after 28 weeks gestations
- treated with aciclovir during inittial infection
- followed immediately by prophylactic aciclovir
- caesarean section recommended in all cases to reduce risk of neonal infection
HIV
human immunodeficiency virus.
HIV positive vs AIDS
Being infected with HIV is referred to as being HIV positive.
AIDS refers to acquired immunodeficiency syndrome.
- AIDS occurs as an HIV infection progresses, and the person becomes immunodeficient.
- This immunodeficiency leads to opportunistic infections and several AIDS-defining illnesses, such as Kaposi’s sarcoma. AIDS is now mostly referred to as late-stage HIV.
what sort of virus is HIV
an RNA retrovirus.
types of HIV
HIV-1 is the most common type, and HIV-2 is rare outside West Africa.
how does HIV cause immunodeficiency
The virus enters and destroys the CD4 T-helper cells of the immune system.
how does HIV cause immunodeficiency
The virus enters and destroys the CD4 T-helper cells of the immune system.
course of HIV infection
1) An initial seroconversion flu-like illness occurs within a few weeks of infection.
2) The infection is then asymptomatic until the condition progresses to immunodeficiency.
3) Immunodeficient patients develop AIDS-defining illnesses and opportunistic infections. This progression occurs potentially years after the initial infection.
transmission of HIV
HIV is not transmitted through day-to-day activities, including kissing. It is spread through:
- Unprotected anal, vaginal or oral sexual activity
- Mother to child at any stage of pregnancy, birth or breastfeeding (called vertical transmission)
- Mucous membrane, blood or open wound exposure to infected blood or bodily fluids, for example, through sharing needles, needle-stick injuries or blood splashed in an eye
4 stage sof HIV infection
1) Seroconversion illness
2) Asymptomatic stage of HIV
3) Symptomatic stage of HIV
4) Symptomatic stage of HIV
5) Late stage HIV
Seroconversion illness
Some people experience a short illness soon after they contract HIV. This is known as seroconversion illness or primary or acute HIV infection.
Presentation
- fever
- fatigue
- headache
- sore throat
- swollen lymph nodes
- diarrhea
Seroconversion is the period when someone with HIV is at their most infectious.
The asymptomatic stage of HIV
Once seroconversion is over, most people feel fine and don’t experience any symptoms. This is often called the asymptomatic stage and it can last for several years.
Though you might feel well at this stage, the virus is active, infecting new cells, making copies of itself and damaging your immune system’s ability to fight illness.
late-stage/ symptmatic HIV
If HIV has a chance to cause a lot of damage to your immune system, you may become ill from certain serious opportunistic infections and cancers. These illnesses are also known as AIDS-defining.
AIDS-Defining Illnesses
These occur where the CD4 count has dropped to a level that allows for unusual opportunistic infections and malignancies to appear.
Examples of AIDS-defining illnesses include:
- Kaposi’s sarcoma
- Pneumocystis jirovecii pneumonia (PCP)
- Cytomegalovirus infection
- Candidiasis (oesophageal or bronchial)
- Lymphomas
- Tuberculosis
screening for HIV
- most people do not know thye are infected and are at risk of spreading the disease
- the earlier the treatment the better the prognosis
how long can it take to test positive for HIV after exposure
3 months to develop anitbodies to virus
consent and HIV testing
Patients need to give consent for a test. Verbal consent should be documented before a test. Consent only needs to be as simple as “are you happy for us to test you for HIV?” Patients no longer require formal counselling or education before a test.
which test is used typically to screen for HIV
1) Antibody testing (4th generation combo assay (EIA)
- can do self sampling at home
2) Testing for P24 antigen
- checks directly for HIV antigen in blood
- can give earlier result
3) PCR testing
- useful for measuring viral load
monitoring of HIV infection
1) CD4 count
2) Viral load
HIV and CD4 count
The CD4 count is the number of CD4 cells in the blood. These are the cells destroyed by the virus. The lower the count, the higher the risk of opportunistic infection:
- 500-1200 cells/mm3 is the normal range
- Under 200 cells/mm3 is considered end-stage HIV (AIDS) and puts the patient at high risk of opportunistic infections
HIV and viral load
Viral load is the number of copies of HIV RNA per ml of blood. “Undetectable” refers to a viral load below the lab’s recordable range (usually 50 – 100 copies/ml). The viral load can be in the hundreds of thousands in untreated HIV.
management of HIV
1) Antiviral therapy
2) Prophylactic antibiotics
3) Prevention of cardiovascular disease
4) Cervical smears
5) Vaccinations
antiviral medication and HIV
- everyone is offered ART irrespective of viral load of CD4 count
- specialist blood tests can establish resistance of each HIV strain to tailr treatment
- aim to ac hieve normal CD4 count and undetectable viral load
- Current recommendation: ** 2 NRTIs (type of ART) + a 3rd agent**
Classes of ART for HIV
Highly Active Anti-Retrovirus Therapy (HAART) Medication
There are a number of classes of HAART medications that work slightly differently on the virus:
- Protease inhibitors (PIs)
- Integrase inhibitors (IIs)
- Nucleoside reverse transcriptase inhibitors (NRTIs)
- Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
- Entry inhibitors (EIs)
what antibiotic is used prophylactically in patients with low CD4 count
Prophylactic co-trimoxazole (Septrin) is given to patients with a CD4 under 200/mm3 to protect against pneumocystis jirovecii pneumonia (PCP).
reducing risk of CVD in patients with HIV
Patients with HIV have close monitoring of cardiovascular risk factors and blood lipids. Appropriate treatment (e.g. statins) may be required to reduce their risk of developing cardiovascular disease.
which vaccinations should HIV positive patients have
influenza, pneumococcal, hepatitis A and B, tetanus, diphtheria and polio vaccines.
Patients should avoid live vaccines.
how to prevent transmission of HIV
Advise condoms for vaginal and anal sex and dams for oral sex, even when both partners are HIV positive. If the viral load is undetectable, transmission through unprotected sex is unheard of, even in extensive studies, although infection is not impossible. Partners should have regular HIV tests.
Where the affected partner has an undetectable viral load, unprotected sex and pregnancy may be considered. It is also possible to conceive safely through techniques like sperm washing and IVF.
preventing transmission of HIV during birth
The mother’s viral load will determine the mode of delivery:
- Normal vaginal delivery is recommended for women with a viral load < 50 copies / ml
- Caesarean section is considered in patients with > 50 copies copies / ml and in all women with > 400 copies / ml
- IV zidovudine should be given during the caesarean if the viral load is unknown or there are > 10000 copies / ml
prophylactic treatment for baby born to HIV pos mother
- Low-risk babies, where the mother’s viral load is < 50 copies per ml, are given zidovudine for four weeks
- High-risk babies, where the mother’s viral load is > 50 copies / ml, are given zidovudine, lamivudine and nevirapine for four weeks
Breast Feeding and HIV
HIV can be transmitted during breastfeeding, even if the mother’s viral load is undetectable. Breastfeeding is not recommended for mothers with HIV. However, if the mother is adamant and the viral load is undetectable, sometimes it is attempted with close monitoring by the HIV team.
Post-Exposure Prophylaxis
- PEP is not 100% effective and must be commenced within a short window of opportunity (less than** 72 hours)**.
- The sooner it is started, the better.
- A risk assessment of the probability of developing HIV should be balanced against the side effects of PEP.
what does PEP invovle
PEP involves a combination of ART therapy. The current regime is
- Truvada (emtricitabine and tenofovir)
- and raltegravir for 28 days.
HIV tests are done immediately and also a minimum of three months after exposure to confirm a negative status. Individuals should abstain from unprotected sexual activity for a minimum of three months until confirmed as negative.
PrEP (pre-exposure prophylaxis against HIV)
prevents HIV before exposure for those at risk of HIV
There are two pills approved for use as PrEP: Truvada® and Descovy®.
- Truvada® is for people at risk through sex or injection drug use.
- Descovy® is for people at risk through sex. Descovy is not for people assigned female at birth who are at risk for HIV through receptive vaginal sex
Hepaitits B transmission
DNA vaccine
It is transmitted by direct contact with blood or bodily fluids.
- Sexual intercourse or sharing needles, for example amongst IV drug users or tattoos.
- Contaminated household products such as toothbrushes or contact between minor cuts or abrasions.
- It can also be passed from mother to child during pregnancy and delivery.
course of hepatitis B
Most people fully recover from the infection within 2 months, however 10% go on to become chronic hepatitis B carriers. In these patients the virus DNA has integrated into their own DNA and so they will continue to produce the viral proteins.
viral markers for hepaitits
- Surface antigen (HBsAg) – active infection
- E antigen (HBeAg) – marker of viral replication and implies high infectivity
- Core antibodies (HBcAb) – implies past or current infection
- Surface antibody (HBsAb) – implies vaccination or past or current infection
- Hepatitis B virus DNA (HBV DNA) – this is a direct count of the viral load
hepatitis B presentation
A serum-sickness-like illness, characterized by fever, arthralgias, and rash, may occur in the prodromal period, followed by constitutional symptoms, anorexia, nausea, jaundice, and right upper quadrant discomfort.
is there a vaccine for hep B
yes- heptitis B surgace antigen
- patients are tested for HBsAb to confirm response. tovaccine
- requires 3 doses
management of hep B
- Have a low threshold for screening patients that are at risk of hepatitis B.
- Screen for other blood born viruses (hepatitis A and B and HIV) and other sexually transmitted diseases
- Refer to gastroenterology, hepatology or infectious diseases for specialist management
- Notify Public Health (it is a notifiable disease)
- Stop smoking and alcohol
- Education about reducing transmission and informing potential at risk contacts
- Testing for complications: FibroScan for cirrhosis and ultrasound for hepatocellular carcinoma
- Antiviral medication can be used to slow the progression of the disease and reduce infectivity
- Liver transplantation for end-stage liver disease
Hepatitis C is what sort of virus and how is it transmitted
Hepatitis C is an RNA virus. It is spread by blood and body fluids. No vaccine is available
course of Hep C
- 1 in 4 fights off the virus and makes a full recovery
- 3 in 4 it becomes chronic
- Complications: liver cirrhosis and associated complications and hepatocellular carcinoma
testing for Hep C
- Hepatitis C antibody is the screening test
- Hepatitis C RNA testing is used to confirm the diagnosis of hepatitis C, calculate viral load and assess for the individual genotype
does Hepaitis C have a vaccine
NOOOOOO
but hep CCCC for curable
management of Hep C
- Have a low threshold for screening patients that are at risk of hepatitis C
- Screen for other blood born viruses (hepatitis A and B and HIV) and other sexually transmitted diseases
- Refer to gastroenterology, hepatology or infectious diseases for specialist management
- Notify Public Health (it is a notifiable disease)
- Stop smoking and alcohol
- Education about reducing transmission and informing potential at risk contacts
- Testing for complications: FibroScan for cirrhosis and ultrasound for hepatocellular carcinoma
- Antiviral treatment
- Liver transplantation for end-stage liver disease
curing hepatitis C
Antiviral treatment with direct acting antivirals (DAAs) is tailored to the specific viral genotype. They successfully cure the infection in over 90% of patients. They are typically taken for 8 to 12 weeks
notifying partners about HIV
- If you’re having protected sex there’s no law saying you must tell your partners that you have HIV. It’s your choice whether you tell them or not.
However, in England and Wales there’s a risk of being prosecuted for reckless transmission of HIV if:
you had sex with someone who didn’t know you had HIV
you knew you had HIV at that time
you understood how HIV is transmitted
you had sex without a condom, and
you transmitted HIV to that person.
risk of tranmsission of BBI
risk of transmission of hep b hep c and HIV
Hep B in 3
Hep C 1 in 30
HIV 1 in 300
risk of assessment for BBI needlestick
PEP and needlestick injury
testing after needlestick
testing after needlestick
conditions in which HIV tests should occur
