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Blood Borne Viruses. Rob Hale Consultant in Special Care Dentistry King’s College London Dental Institute. Blood Borne Viruses. Viruses HBV HCV HIV Statistics General Prison Occupation exposures Oral health care Issues. Hepatitis B. Virus First isolated in 1969

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Blood borne viruses

Blood Borne Viruses

Rob Hale

Consultant in Special Care Dentistry

King’s College London Dental Institute

Blood borne viruses1
Blood Borne Viruses

  • Viruses

    • HBV

    • HCV

    • HIV

  • Statistics

    • General

    • Prison

  • Occupation exposures

  • Oral health care Issues

Hepatitis b
Hepatitis B


First isolated in 1969

Virions known as “Dane particles”

Hepadna virus with circular DNA genome

Clinical features

incubation period of 2-5 months

insidious onset

asymptomatic infections can occur

symptoms may include

short, mild flu-like illness

nausea, vomiting, diarrhoea

loss of appetite, weight loss

jaundice, itchy skin, muscle pain, arthralgia, rash

Hepatitis b1
Hepatitis B


infection transmitted parenterally

virus replicates in liver

viral particles, surface protein shed into blood

About 30% have no signs or symptoms

Most patients with clinical hepatitis will recover completely with no untoward long term effects

Hepatitis b complications
Hepatitis B - complications

  • Carrier status

    HBV persists for > 6 months

    develops in 5-10%

    carriage may persist up to 20 years and be asymptomatic

    carrier status more likely in:

    those who have received blood products

    those co-infected with HDV

    those with immune defects

  • Persistent infection

    Approx 5% fail to eliminate the virus completely

    These at risk include – babies, young children, immunocompromised, males>females

    ongoing liver damage occurs because of host response against infected liver cells

    Chronic infection

    Chronic persistent hepatitis

    Chronic active hepatitis – cirrhosis, liver failure


    Treatment for chronic HBV – Interferon


Hepatitis b serology
Hepatitis B - serology


Surface antigen ( HBsAg)

virus replication is occurring in the liver

“e” antigen ( HBeAg)

high level of virus replication

high infectivity

Core antigen ( HBcAg)

not found in blood


Antibody response

Surface antibody (anti- HBs)

Detectable late in convalescence, indicates immunity following infection,

detectable for life, not found in chronic carriers

“e” antibody (anti-Hbe)

Detectable as viral replication falls, indicates low infectivity in a carrier

Core IgM

Rises early infection and indicates recent infection

Core IgG

Rises soon after IgM, present for life in chronic carriers and those who clear the virus , indicates exposure to HBV

Hepatitis b prevention
Hepatitis B - prevention

  • Active immunisation

    • Serum derived

    • Recombinant

      Three doses induces protective level of antibodies

      Vaccines should be administered to

    • healthcare workers

    • sexual partners of chronic carriers

    • infants of HBV carrier mothers

  • Passive antibody

    Hep B immune globulin administered to non immune individuals following single exposure to Hep b infected blood

    i.e. Needle stick injuries

Hepatitis c
Hepatitis C


  • Togavirus with single stranded RNA

  • six genotypes identified

  • responsible for most cases of “non-A, non B hepatitis”

  • ranks second only to alcoholism as cause of liver damage

    Clinical features

  • incubation period of 6-8 weeks

  • causes a milder form of acute hepatitis than HBV

  • No signs or symptoms for many on infection

  • Mild, flu-like illness, nausea, vomiting, loss of appetite, weight loss, jaundice

  • Many individuals develop chronic infection following exposure

Hepatitis c1
Hepatitis C

Infection transmitted parenterally

About 20% of individuals will clear the virus within 6 months but this does not mean they are immune from future infection

80% will develop chronic hepatitis C infection – remain lifelong carriers/infectious

Hepatitis c2
Hepatitis C


Chronic hepatitis

Liver cirrhosis

Liver failure

Liver cancer (<3%)




Hiv aids


Human immunodeficiency virus


Acquired immunodeficiency syndrome

What’s the difference?

Blood borne viruses

RNA virus

Reverse transcriptase

Transmitted parenterally

Hiv antibody test
HIV antibody test


  • Western blot

A positive test indicates:

  • Exposure to the virus

  • Persistent infection

  • Infectiousness

    It does not indicate AIDS

Hiv progression
HIV Progression

  • Becoming HIV antibody positive

  • Seroconversion illness

  • Asymptomatic HIV infection

  • Symptomatic HIV infection

  • AIDS diagnosis

Medical monitoring
Medical monitoring

  • FBC

  • CD4

    • 600- 1600 cells/mm3

  • Viral load

Medical monitoring1
Medical Monitoring


  • Monitors immune system

  • Help decide when to start therapy

  • Monitor effectiveness of drugs

    Viral Load

  • Identifies number of HIV particles

  • Help decide when to start therapy

  • Monitors effectiveness of drugs


  • Highly active antiretroviral therapy (HAART

    • Reverse transcriptase inhibitors

      • Nucleoside analogues ( AZT,ddI, ddC, d4T)

      • Non-nucleoside analogues ( nevirapine)

    • Protease inhibitors

      • Saquinavir, Retonavir etc

  • Combination therapy

Side effects of medication


Back pain






Abdominal pain

Skin rash

Changes in taste

Burning sensation of skin

Muscle pain

Peripheral neuropathy

Mouth ulcers




Side effects of medication


  • Blood/blood products

  • Organ donation

  • Sexual intercourse

  • Artificial insemination with infected semen

  • Horizontal transmission

  • Vertical transmission

  • Unknown – Hep C

Hepatitis c3
Hepatitis C

Approx 191,000 individuals between 15-59 years with antibodies to Hep C in England & Wales in 2003

Equates to approx 142,000 individuals with chronic Hep C infection

Approx 0.4% of general population

In Scotland, approx 50,000 infected of which 38,000 have chronic infection

Northern Ireland approx 4000 individuals likely to be infected

Hepatitis c4
Hepatitis C

Difficult to estimate new infection rates due to long time between infection and development of severe disease/death

Increase in incidence until late 1980s peaking at about 14,900 in 1988

Larger degree of uncertainty of estimates for later years

Hepatitis c5
Hepatitis C

Wide variation of HCV incidence in injecting drug users

England 3.01- 41.8%

Scotland 11.9 – 28.4 %

Establishing contribution of this incidence to future prevalence of infection requires knowledge of IDU population

2004 study estimated between 100,000 – 150,000 current injectors in England in 2000

Blood borne viruses

  • Estimated 77,400 persons living with HIV in UK by end of 2007

  • During 2007 7,743 new diagnoses

    • 55% heterosexual contact – majority acquired HIV abroad

    • 41% MSM

  • 70% of persons seen for HIV care were receiving antiretroviral therapy

  • Almost one in five with severe immunosuppression were not on therapy

  • Almost a third of persons newly diagnosed were diagnosed late

    • At a point at which therapy should have begun (CD4<200 )

Hiv and hepatitis in prisons
HIV and hepatitis in prisons

Globally rates of HIV and hepatitis in prisons are higher than general populations


England & Wales in 1997 –

0.3% adult males, 1.2% adult females

Scotland in 1997 –

0.3% adult males, 0.6% adult females

Hepatitis C

England & Wales in 1997 –

9% adult males and 11% adult females

Scotland –

8% adult males, 14.8% adult females

Hiv and hepatitis in prisons1
HIV and hepatitis in prisons

Since 1997 prison population has increased by approx 29%

Has the number of prisoners infected with blood borne viruses also increased by this amount or more?

Nature of prison population

Risks of transmission specific to prison environment

Nature of prison population
Nature of prison population

High risk for infection even before imprisonment

IV drug users

  • 29% female, 24% male, 4% young offenders

    >90% HCV infections are through IVDU

Risks of transmission specific to prison environment
Risks of transmission specific to prison environment


  • One in five prisoners report having used heroin at some time whilst in prison (SSD/NAC 2005)

  • Sharing of needles/equipment

Risks of transmission specific to prison environment1
Risks of transmission specific to prison environment

Sexual activity

  • 2% of a sample of 208 prisoner participants had had forced penetrative sexual intercourse (2004)

  • In a population of approx 75,000 – how many victims would that make!

  • How many new infections?

  • Overcrowding, mental health problems, inadequate staff levels, absence of conjugal rights, homophobia, general intolerance, restriction of condoms

  • Sexual behaviour in situation of intimidation and violence – more risk of tearing and bleeding

Risks of transmission specific to prison environment2
Risks of transmission specific to prison environment


  • Fights/assaults

  • One in 10 men reported being assaulted

  • Gross under reporting

  • When bleeding occurs – may be low risk for HIV but greater for HCV


  • Sharing tattooing equipment

  • 11% of study sample had been tattooed in prison

  • Fifth of those who had been tattooed had been tattooed whilst in prison

    (Strang 1998)

Occupational exposure1
Occupational Exposure

Since 1997 in UK:

3773 OE to blood or other high-risk body fluid

1595 of these from London

76% were percutaneous injuries

Occupational exposure2
Occupational exposure

Risk of infection following a percutaneous injury:

HBV 1 in 3

HCV 1 in 30

HIV 1in 300

Department of Health

HIV Prophylaxis : Guidance from the UK Chief Medical officers Expert Advisory Group on AIDS

September 2008From 2000-2007

68% attributed to hollow bore needles

19% solid needles

13% “other sharps” e.g scalpels, dental probes

United Kingdom Surveillance of Significance Occupational Exposures to Blood Borne Viruses in Healthcare Workers 2008

Occupational exposure3
Occupational Exposure

Deep penetrating injuries with hollow bore needles

Device visibly contaminated with blood

Needle from source patient's artery or vein

Terminal HIV related illness in source patient

Exposures to hcv hiv hbv1
Exposures to HCV, HIV, HBV

Of 15 seroconversions in UK:

One dentist seroconverted to HCV reported in 2001

Key recommendations
Key recommendations

Injuries with hollow bore needles remain most commonly reported occupational exposure in healthcare setting

HCV exposures remain greatest proportion of percutaneous exposures

HCWs exposed to HCV positive source patient still not receiving follow-up testing in line with national guidance

No new HIV seroconversions since 1999

78% HCWs exposed to HIV positive source patient began PEP.

37% within an hour and 89% within 24 hours

Post exposure prophylaxis
Post exposure prophylaxis

  • Truvada ( 300mg Tenofovir/200mg Emtricitabine) once a day

    (nucleoside reverse transcriptase inhibitor)

  • 2 Kaletra film-coated tablets ( 200mg Lopinavir/50mg Ritonavir) twice a day (protease inhibitor)

  • PEP as soon as possible after exposure, ideally within an hour following careful risk assessment

  • PEP now generally not recommended after 72 hours post exposure

  • Follow –up 12 weeks after exposure

    If PEP taken for at least 12 weeks from when PEP stopped

    Longer follow-up for complex/co-infected cases

Side effects


gastrointestinal disturbances

(vomiting, abdominal pain, faltualence, diarrhoea)

anorexia, pancreatitis, liver damage

dyspnoea, cough, headache

insomnia, dizziness, fatigue

blood disorders (anaemia,

neutropenia, thrombocytopenia)

myalgia, arthralgia, rash, urticaria, fever



gastrointestinal disturbances

(vomiting, abdominal pain, faltualence, diarrhoea)

anorexia., hepatic dysfunction,


blood disorders (anaemia,

neutropenia, thrombocytopenia)

sleep disturbances, headache,

dizziness, fatigue, parathesia,

Myalgia, myositis, rhabdomyolysis,

taste disrturbances, rash, pruritis,

Steven-Johnsons syndrome,


Side effects

Infected health care workers
Infected Health Care Workers

  • Seek confidential professional advice if believe to have been exposed

  • Majority procedures in health care setting pose no risk

  • Those infected must seek expert medical advice

  • Avoid exposure prone procedures

The majority of procedures in dentistry are exposure prone except
The majority of procedures in dentistry are exposure prone except

  • Exam with mouth mirrors

  • Taking extra-oral radiographs

  • Visual/digital exam of head & neck

  • Visual/digital exam of edentulous mouth

  • Taking impressions of edentulous mouth

  • Construction & fitting of full dentures

Oral health care

Oral Health Care except

(Decontamination and infection control – goes without saying)

Oral health care1
Oral health care except


Drug metabolism

Bleeding tendencies

Liaise with liver physician


Dental treatment for hiv antibody positive individuals
Dental treatment for HIV antibody positive individuals except

  • Bleeding

    • Thrombocytopenia

  • Infections

    • Neutropenia

    • Antibiotic prophylaxis

  • Wound healing

  • Local anaesthesia

    • Indinavir reaction

Oral manifestations of hiv infection
Oral Manifestations of HIV Infection except

  • Group 1 - Lesions strongly associated with HIV infection

  • Group 2 – Lesions less commonly associated with HIV infection

  • Group 3 – Lesions seen in HIV infection

Lesions strongly associated with hiv infection
Lesions strongly associated with HIV infection except

  • Candidiasis - pseudomembranous


  • Oral hairy leukoplakia

  • Necrotising ulcerative gingivitis

  • Necrotising ulcerative periodontitis

  • Kaposi’s sarcoma

  • Non-Hodgkin’s lymphoma

General considerations
General Considerations except

  • The principles of good oral health care are the same for patients with blood borne virusesas they are for all patients.

  • There is no justification for modifying dental treatment based solely on status.

  • Alterations may be indicated on the basis of medical problems that occur as a result of infection.

    Consider each patient individually.

General considerations1
General Considerations except

  • Despite the immunological problems resulting from HIV infection, few complications from dental treatment have been reported.

  • The successful management of any oral manifestations and good oral health care can improve the quality of life for the patient.

Blood borne viruses

“Prisons are breeding grounds for blood-borne viruses because they bring together a population with a disproportionate rates of high-risk behaviours in overcrowded and adverse conditions”

Dame Ruth Runciman

National AIDS Trust Chair

Prison Reform Trust Deputy Chair

HIV and hepatitis in UK prisons: addressing prisoners’ healthcare needs(2005)