Epidemiology, pathogenesis, diagnosis and dental relevance HIV

Question 1

what infection occurred in individuals before HIV was known?

Answer 1

Pneumocystis pneumonia

Oct 1980-June 1981, LA

Question 2

what individuals did Pneumocystis pneumonia infect?

Answer 2

young, active homosexual men

all had previous or current CMV and oral mucosal candidosis

Question 3

what rare cancer was seen in 41 homosexuals?

Answer 3

Kaposi’s sarcoma

Question 4

what was associated with Kaposi’s sarcoma and Pneumocystis pneumonia?

Answer 4

massive decrease in T cells

Question 5

what are T cells important in?

Answer 5

immune system protection for infections and cancers

Question 6

what are the 2 main groups of T cells

Answer 6

Killer

Helper

Question 7

what do killer T cells do

Answer 7

circulate the body, scan for abnormal cells and destroy

Question 8

what do helper T cells do

Answer 8

messengers, imitate activity other immune cell and generate antibodies

Question 9

Kaposi’s sarcoma

Answer 9

Previously rare - associated with elderly (immunocompromised) and generally non-aggressive

The most frequent opportunistic tumour observed in 20% of patients with AIDS (mostly homosexuals).

Now associated with a human herpes virus

Question 10

what was the first mode of transmission of the virus identified?

Answer 10

sexual transmission

Question 11

what other groups were affected by the virus?

Answer 11

groups typically associated with immunosuppression

• women (associated with injecting drug use or sexual contact with men who had AIDS)
• Haitians residing in the US (all young and denied homosexual activity)
• Heterosexual men with haemophilia – all received factor VIII
  groups of people affected spread beyond MSM

Question 12

when was the name AIDS acquired and what does it stand for?

Answer 12

1982

Acquired Immunodeficiency Syndrome

Question 13

what is the causative agent of AIDS

Answer 13

Human Immunodeficiency virus (1984)

Question 14

what is AIDS

Answer 14

is a syndrome or range of symptoms, that may develop in time in a person with HIV

Question 15

when was the first test for HIV-1 approved?

Answer 15

1985 in America

Question 16

what was the first HIV-1 test like

Answer 16

Very sensitive but high false positive rate (low specificity)
- Give a wrong diagnosis to someone and no way of confirming either way

Question 17

what was the first HIV-1 test used for

Answer 17

• routine diagnosis
• screening blood donations

Screening tests were augmented with confirmatory tests allowing expansion of testing to wider populations for diagnostic purposes

Question 18

when was testing and ‘clear’ status of US blood banks

Answer 18

April 1985, clear by July

6-month period before blood testing in UK
- Unclear why
(Logistics? One company licensed to produce test – not sufficient capacity to assess all countries)

Question 19

what is the confirmatory test for HIV

Answer 19

ELISA positive results all checked again – disregard false positives so give correct diagnosis

Question 20

what was a process that helped build a stigma around HIV

Answer 20

Pre-test counselling:

- knew what test was for and consequences of those tests

Question 21

mistakes by the UK surrounding HIV/AIDS stigma

Answer 21

late action

Iceberg advert (shock and shame) – shock people into changing their behaviour

• Hindsight wrong thing to do. Made a lasting stigma
• Now Hope for adverts
• National HIV Testing Week starts Saturday 16 November
• There is no shame in knowing your status

Question 22

what is the new style of HIV care

Answer 22

Test and Treat approach
- Due to very good drugs, prevent them from suffering from opportunistic infections
Know most infections come from an unaware host – reduce their infectivity by testing and treating – reduce spread

More positive view

Question 23

how is HIV transmitted (5)

Answer 23

• Unprotected sex
• Drug addicts
• Blood transfusion
• Pregnancy
• Non-sterile instruments

Question 24

how is HIV not transmitted (5)

Answer 24

• Touching
• Through food
• Kissing
• Insect bites
• In the pool

Question 25

what is HIV PrEP

Answer 25

Anticipatory treatment - Available on NHS in Scotland since July 2017 for HIV negative individuals who are at risk (consistent high risk sexual encounters) Take daily, build up protective levels in build steam, HIV cannot take hold when exposed

Question 26

where did HIV come from

Answer 26

Xenosis – derived from animals, jump to humans (e.g. avian flu) - From chimp, via ingestion and/or blood exposure 1970s move from Congo to Haiti, then America, then Global 1980s peak

Question 27

what is the global impact of HIV/AIDS

Answer 27

37.9 million people living with HIV globally, 21% don’t know their status

Question 28

what is happening to the number of new HIV diagnoses

Answer 28

decreasing in most part 1. 8 million people newly infected in 2017 globally - 26% decrease in number of new infections across the global population since 2010 New infections still increasing for some places Battle not won concern - Women more new infections than males now (social context – vulnerable to sexual violence)

Question 29

what is happening in relation to number dying compared to number living with HIV infection

Answer 29

Less dying of infection but more living with infection | - As the number of people receiving treatment in increasing

Question 30

HIV WHO targets for 2020

Answer 30

90% aware of infectious state 90% on HIV treatment 90% have undetectable viral levels

Question 31

how is Scotland doing in HIV levels

Answer 31

300-250 new transmissions a year - 91% aware of status, - 87% (less) on treatment (not all getting specialist care – 96%), - nearly 100% (97%) virally supressed (low enough level in blood very unlikely to pass on infection) Deaths in Scotland - 40-50 per year

Question 32

how many main viruses are there of HIV

Answer 32

2

Question 33

what type of virus is HIV

Answer 33

small retrovirus

Question 34

structure of HIV

Answer 34

``` Main structural (core) protein p24 encases - P9 and P7 - Single stranded RNA - Reverse transcriptase Then there’s matrix protein p17 ``` With a lipid membrane envelope (host-derived) with host proteins and envelope glycoproteins (gp41, gp120) - Since lipid virus hard to survive out with host 2 glycoporteins: important in replication, facilitate entry into body’s CD4 cell Once in release Viral RNA, enzymes of virus convert into DNA and then inserted into body’s DNA

Question 35

what are the glycoporteins role in HIV virus

Answer 35

important in replication, facilitate entry into body’s CD4 cell

Question 36

how does being a lipid virus impact on how HIV can live

Answer 36

hard to survive out with hosts

Question 37

how does HIV replicate in host

Answer 37

Body replicating CD4 cells replicate virus | - Small infection causes billions of infected virus cells in small time span

Question 38

what type of HIV causes pandemics

Answer 38

HIV 1 causes pandemic - Multiple strains 3 groups: major, new and other - New and other in West Africa - Main seen distributed globally

Question 39

how many groups of HIV 1 are there

Answer 39

3 groups: major, new and other - New and other in West Africa - Main seen distributed globally

Question 40

5 key stages in HIV life cycle

Answer 40

1. HIV releases genetic material into CD4 cell 2. Reverse transcriptase copies RNA – DNA 3. Viral DNA inserted in cell DNA 4. Many copies of the viral RNA and proteins made 5. New viral particles assemble and bud from cell Small minority of T4 cells are infected

Question 41

virus half life of HIV

Answer 41

5.7 hours

Question 42

how many HIV virons per ml of blood

Answer 42

100 - 10 million

Question 43

course of HIV disease

Answer 43

Start of infection: huge number of virus circulating in body - Asymptomatic period (if do flu like) - Non-specific, unaware Then between 2-15 years (variable) extended period, virus multiplies in body and body can no longer keep on top of it CD4 drops and virus in circulation increases - No therapy = death

Question 44

AIDS definition

Answer 44

the presence of one of 25 conditions indicative of severe immunosuppression or HIV infection in an individual with a CD4+ cell count of <200 cells per cubic mm of blood therefore, is end point of long-established infection (continuous, progressive or pathogenic)

Question 45

clinical features of AIDS

Answer 45

Lymphadenopathy and fever - Insidious onset - May be accompanied by weight loss and malaise Opportunistic Infections - Pneumocystis carinii pneumonia - Cerebral toxoplasmosis - Cryptococcal meningitis - Candidosis - Herpes virus infections - Diarrhoeal disease Malignancies - Kaposi’s Sarcoma - Non-Hodgkins lymphoma Wasting - Common in Africa AIDS-related dementia - Disease in cognitive and/or motor function

Question 46

4 alternative tests for HIV/AIDS

Answer 46

Rapid tests Oral fluid tests Dried blood spot (DBS) - easy to obtain – good for research At home kits (2014) - sampling and testing - All positive results must be confirmed Big change from 80s with pre-test counselling

Question 47

improved diagnosing of HIV infection

Answer 47

Antibody tests: - sensitive but only pick up 6-12 weeks post infection (many misses 2nd generation assays, 3rd – closer Viral antigen detection better than antibodies (2 weeks and detects virus) PCR (1-2 weeks)

Question 48

dental relevance of HIV

Answer 48

HIV infected individuals have poorer oral health and greater dental care needs than the general population BUT Experience high levels of HIV-related stigma and discrimination when attending dental services - double-gloving, end of day appointments etc Standard Infection Control Procedures mean no risk Need HIV positive to come into practice – oral lesions they have can cause pain and affect mental health

Question 49

3 groups of oral lesions related to HIV

Answer 49

Group 1 - Key - Lesions strongly associated with HIV infection - Candidosis, Hairy Leukoplakia, Kaposi’s sarcoma, Non-Hodgkin’s lymphoma, Periodontal disease Group 2 - Lesions less commonly associated with HIV infection Group 3 - Lesions seen in HIV infection

Question 50

HIV screening in dental setting

Answer 50

Key prevention strategy is to improve the availability and access to HIV screening Early diagnosis improves health outcomes and provides opportunities to prevent further transmission events Several key HIV indicator that are encountered by the dental professional Rapid point of care HIV tests could be used to offer chairside HIV screening to patient during dental appointments Individuals advised recommended to get diagnosis if present dental

Question 51

infection control in the dental setting

Answer 51

Both patients and dental professionals can be exposed to pathogens Contact with blood, oral and respiratory secretions and contaminated equipment occurs Proper procedures can prevent transmission of infections to patients and dental professionals (Follow controls = no risk All are exposed to pathogens)

Question 52

what is a famous case that causes fear in the general public in failure of infection control procedures

Answer 52

the Florida Dentist - First incident of clinical transmission of HIV - Investigation strongly suggests that five patients (patients A, B, C, E, and G) became infected with HIV while receiving care from a dentist with AIDS - Numerous patient notifications exercises associated with the dental setting – no further cases of transmission since

Question 53

what is regularly monitored in health care workers?

Answer 53

viral load

Question 54

what is the duty of candor legislation

Answer 54

requires health care professionals to notify patients if they have been put at risk of infection

Question 55

what is important to remember about needletstick injuries

Answer 55

they are common hard to acquire infection (prevalence and risk of transmission in population) risk is further reduced by - source on cART with undetectable viral load - follow up and management with PEP Risk of transmission reduced when undetectable viral load – means HIV untransmissible

Question 56

how is risk of infection by needle stick injury further reduced

Answer 56

- source on cART with undetectable viral load - follow up and management with PEP Risk of transmission reduced when undetectable viral load – means HIV untransmissible

Question 57

dental professionals should

Answer 57

- possess adequate knowledge about HIV infection and the significance of oral lesions associated with HIV which may help identify those who would benefit from HIV testing - provide HIV patients with oral healthcare of the highest standards. A focus on routine and preventative care will maintain and improve the quality of life for patients with HIV - Infection control measures should be strictly followed - Dental professionals have a legislative duty to report all sharps injuries and seek appropriate follow up and management as per local policies.