blood borne pathogenes

1. Blood borne pathogens
DR RITESH SHIWAKOTI
MScD PROSTHODONTICS

2. • Bloodborne pathogens are infectious
microorganisms present in blood that can
cause disease in humans. These pathogens
include, but are not limited to, hepatitis B
virus (HBV), hepatitis C virus (HCV), and
human immunodeficiency virus (HIV), the
virus that causes AIDS.

3. • Bloodborne infections are those where the
blood contains infectious agents that can be
transferred into the body of another person
giving rise to infection (Advisory Committee
on Dangerous Pathogens)

4. Factors involved in the risk of transmission include:
• The length of time that the infectious agent
remains in the blood
• The amount of agent that is present
• Its virulence (i.e. its ability to cause disease) and
• The susceptibility of the recipient

5. OPIM “Other Potentially Infectious
Materials” means:
1. Semen
2. Vaginal secretions
3. Cerebrospinal fluid
4. Synovial fluid
5. Pleural fluid
6. Pericardial fluid
7. Peritoneal fluid
8. Amniotic fluid
9. Saliva in dental procedure
any other body fluid that is visibly contaminated with blood
such as saliva or vomitus, and all body fluids, such
as emergency response.

6. 2. Any unfixed tissue or organ (other then intact
skin) from a human (living or dead)
3. HIV – Containing cell or tissue cultures
Organ culture, and
HIV- or HBV- containing culture medium or
other solutions: blood, organs, or other tissues
from experimental animals infected with HIV or
HBV, needle sticks, human bites, cuts, and
abrasions.

7. Other body fluid
Excreta and secretions i.e. urine, faeces, sputum,
tears, sweat and vomit are considered to
present little risk from bloodborne infection
unless they contain visible blood. However,
they may pose a risk of infection for other
reasons

8. Routes of transmission
Percutaneous exposure through:
Major routes
• Sharing injecting equipment
• Skin puncture by contaminated sharp objects
such as needles, instruments or glass
• Transfusion of infected blood products

9. Less common routes
• Contamination of open wounds and skin
lesions
• Human bite (transmission of HBV and HIV
have been documented but not quantified)

10. Mucocutaneous exposure through:
Major routes
• sexual intercourse
• childbirth and/or breastfeeding in infected
mothers

11. Less common routes
• Contamination of mucous membranes of the
eye, nose or mouth (transmission of HBV and
HIV following exposure of mucous
membranes)

12. Risks to health workers
Risk of occupational transmission occurs whenever there
is exposure to blood or body fluids.
• Health workers who are regularly involved in invasive
procedures, i.e. any use of needles, or instruments in
penetrating the body, or otherwise in contact with
blood or body fluid.
• Sharps injury is by far the most commonly reported
exposure amongst health workers

13. Examples include
• Surgery
• Obstetrics and gynaecology
• Dentistry
• Accident and emergency work
• Post-mortem
• Venepuncture and phlebotomy.
Ancillary and other staff may also be put at risk
through careless disposal of sharps, linen and
clinical waste.

14. Transmission to patients during
invasive procedures
• Doctors were reported as not always washing their
hands or changing gloves (if worn) between cannula
insertions
• It was not usual practice for staff to wash their hands
or change gloves between volunteers when taking
blood samples
• Kidney dishes used to transport samples and
equipment were not decontaminated or discarded
between volunteers
• Equipment contaminated with blood was sometimes
left on bedside lockers.

15. Control measures
• Universal precaution
• wash hands before and after every patient contact, and
immediately after direct contact with blood or body
fluids, avoid hand to mouth/eye contact
• wear gloves when contact with blood or body fluids,
mucous membranes or non-intact skin is anticipated,
and wash hands after their removal
• Prevent puncture wounds, cuts and abrasions in the
presence of blood and body fluids

16. • Protect skin lesions and existing wounds by means of
waterproof dressings and/or gloves
• Avoid use of, or exposure to, sharps and sharp objects
when possible, but where unavoidable take particular care
in their handling and disposal
• Avoid contamination of the person by use of waterproof or
water-resistant clothing, plastic apron, etc.
• Wear rubber boots or plastic disposable overshoes to
protect shoes; when the floor is contaminated with blood,
wash hands after removing footwear
• Control surface contamination by blood and body fluids by
containment and appropriate decontamination procedures

17. Management of exposure to blood or
body fluids
• Wash off splashes on skin with plenty of soap and water;
• If the skin has been punctured or broken, encourage bleeding but
without pressing or sucking the wound
• Splashes to the eye, nose, or mouth should be washed out with
copious amounts of water (sterile water for the eye if available);
• Record the source of contamination, i.e. name of source (if known),
type of fluid, type of injury, and how it occurred;
• Report the injury to the supervisor, line manager or other person
responsible for health and safety at work, as in local policy;
• Medical advice should be sought from the occupational health
department or other medical adviser without delay, in accordance
with local policy.

18. Further action
The local plan for management of exposure should consider:
• The source of contamination and the extent of
injury/exposure;
• Blood sampling and/or serum sample storage;
• Vaccination status;
• Provision of immediate and follow-up counselling and
support;
• The need for post-exposure prophylaxis;
• Completion of accident forms;
• Surveillance of incidents;
• Review of procedures.

19. Human immunodeficiency virus (HIV)
• Worldwide, the majority of HIV infections are
caused by human immunodeficiency virus type 1
(HIV 1).
• A second virus, HIV 2, is found mainly in West
Africa but has been detected in individuals in
other areas of sub-Saharan Africa, the USA, India
and Europe.
• A further virus, a sub-type of HIV 1, has recently
been recognized and is referred to as HIV 0.

20. Epidemiology
• HIV/AIDS is a global pandemic. As of 2011
approximately 34 million people have HIV
worldwide .Of these, approximately
17.2 million are men, 16.8 million are women
and 3.4 million are less than 15 years old.
There were about 1.8 million deaths
from AIDS in 2010, down from 2.2 million in
2005.

21. • Sub-Saharan Africa is the region most affected
• South & South East Asia (a region with about 2
billion people as of 2010, over 30% of the
global population) has an estimated 4 million
cases (12% of all people living with HIV), with
about 250,000 deaths in 2010. Approximately
2.5 million of these cases are in India
• Since AIDS was first recognized in 1981 and by
2009 has led to nearly 30 million deaths.

22. • Officially, the Philippines is a low-HIV-prevalence
country, with less than 0.1 percent
of the adult population estimated to be HIV-positive.
As of January 2013, the Department
of Health (DOH) AIDS Registry in the
Philippines reported 10,514 people living with
HIV/AIDS.

23. PATH-PHYSIOLOGY
• HIV is a retrovirus.
• Retroviruses contain two strands of RNA and
are able to transcribe their RNA into a DNA by
means of an enzyme, reverse transcriptase.
• The HIV virus binds, with a specific cellular
receptor CD4 antigen, present on the surface
of certain cells.

24. • These CD4 receptor cells include helper T-lymphocytes,
mononuclear phagocytes,
macrophages and glial cells in the brain.
• After binding to a cell the HIV virus enters and
forms a DNA copy through reverse
transcription.
• This copy is then integrated into the host cell
DNA, where it remains in a relatively inactive
state.

25. • Over time cell damage occurs, and there is a
continuing reduction in the numbers of
circulating helper T-cells and other CD4 cells
• Resulting in an increasingly compromised
immune response and, in some individuals,
progressive brain damage.

26. Transmission:
• Sexual contact with infected person
• Needle-sharing during intravenous drug use
• Needle stick injury
• Transfusion of contaminated blood or blood
product
• Medical injections with unsterilized
equipment.
• From mother to child during pregnancy,
during delivery, or through breast milk

27. Symptoms
Primary Infection, or Acute Retroviral Syndrome
• Fever,
• Myalgia (muscle pain),
• Headache,
• Nausea, vomiting, diarrhea,
• Night sweats,
• Weight loss,and
• Rash.
These signs and symptoms usually occur 2–4 weeks after
infection, subside after a few days, and often are
misdiagnosed as influenza or infectious mononucleosis.

28. Clinical Latency/Asymptomatic Disease
(Clinical Stage 1)
Period of years between HIV infection and
clinical signs and symptoms of AIDS.
This is when the “viral set point” is established.
The viral load of the set point can be used to
predict how quickly disease progression will
occur and this phase may last 8–10 years

29. Mild Signs and Symptoms of HIV (Clinical Stage 2)
• Candidiasis,
• Lymphadenopathy,
• Molluscom contagiosum,
• Persistent hepatosplenomegaly,
• Popular pruritic eruptions,
• Herpes zoster, and/or
• Peripheral neuropathy

30. Advanced Signs and Symptoms of HIV
(Clinical Stage 3)
• Cryptosporidiosis ( parasitic infection )
• Pulmonary and lymph node tuberculosis,
• Wasting
• Persistent fever (longer than one month)
• Persistent candidiasis
• Recurrent bacterial pneumonia and
• Other opportunistic infections is common.

31. Clinical Stage 4

32. Investigation
• Enzyme-linked immunosorbent assay
• DNA PCR and RNA PCR
• Western blot analysis
• Immunofluorescence assay

33. Prevention
• Condom
• A vaginal gel containing tenofovir
• Post-exposure prophylaxis (PEP) A course of
antiretrovirals administered within 48 to
72 hours after exposure for 4 week e.g.
zidovudine , lamivudine , indinavir
• 2013, the prevention regimen recommended
in the United States consists of three
medications—
tenofovir, emtricitabine and raltegravir

34. Vaccination
As of 2012 , single trial of the vaccine RV
144 published in 2009 found a partial
reduction in the risk of transmission of roughly
30%, stimulating some hope , further trials of
the RV 144 vaccine are ongoing.

35. Antiviral therapy
Most current HAART regimens consist of three(3)
drugs: 2 NRTIs + a PI/NNRTI
Examples of NRTIs include deoxythymidine, zidovudine, stavudine, didanosine,
zalcitabine, abacavir, lamivudine, emtricitabine, and tenofovir
NNRTIs, include nevirapine, delavirdine, efavirenz, and rilpivirine
HIV protease inhibitors
Lopinavir,Indinavir, Nelfinavir, Amprenavir and Ritonavir

36. Prognosis
• Over time continuing CD4 cell depletion leads
to increasing immunosuppression,
opportunistic infections and eventual death
for the majority

37. Hepatitis B virus
• It is a double-stranded DNA hepadnavirus and
the whole virus is called the Dane particle.
• The hepatitis B virus is a major cause of acute
and chronic hepatitis, cirrhosis and
hepatocellular carcinoma worldwide.

38. Epidemiology
• In 2004, an estimated 350 million individuals
were infected worldwide. National and
regional prevalence ranges from over 10% in
Asia to under 0.5% in the United States and
northern Europe
• Philippines has 16 million people infected with
Hepatitis B virus (HBV)

39. Transmission
• Sexual contact
• Blood transfusions and transfusion with other
human blood products
• Re-use of contaminated needles and
syringes, and
• Vertical transmission from mother to child
(MTCT) during childbirth

40. Signs and symptoms
Acute viral hepatitis – an illness that begins
• General ill-health
• Loss of appetite
• Nausea
• Itchy skin
• Vomiting
• Body aches
• Mild fever
• Dark urine
• Jaundice

41. Chronic infection with hepatitis B virus either
may be asymptomatic or may be associated
with a chronic inflammation of the liver
(chronic hepatitis), leading to cirrhosis and
incidence of hepatocellular carcinoma (liver
cancer)

42. • Symptoms outside of the liver are present in
1–10% of HBV-infected people and
include serum-sickness–like syndrome, acute
necrotizing vasculitis(polyarteritis nodosa),
membranous glomerulonephritis

43. Investigation
• Enzyme-linked immunosorbent assay
• DNA PCR and RNA PCR
• Western blot analysis
• Immunofluorescence assay

44. Prevention
Hepatitis B vaccine:
- A course of 3 vaccine injections are given with
the 2nd injection at least 1 month after the 1st
dose and the 3rd injection given six months after
the 1st dose.

45. Newborn (with carrier mothers):
- hepatitis B vaccine (HBV 1) and hepatitis B
immune globulin (HBIG) within 12 hours of
birth, followed by a second dose of hepatitis B
vaccine (HBV 2) at 1–2 months and a third dose
at and no earlier than 6 months (24 weeks)

46. • For carrier mothers: multiple injections of small
doses of hepatitis B immune globulin or oral
lamivudine in HBV carrier mothers with a high
degree of infectiousness in last trimester
• Poor responses are mostly associated with being
over the age of 40 years, obesity and smoking,
and alcoholics, advanced liver disease. Patients
on renal dialysis may respond less well and
require larger or more frequent doses of vaccine.

47. • As of 2008, there are seven medications licensed for
treatment of hepatitis B infection in the United States.
• Include antiviral lamivudine, adefovir , tenofovir , telbi
vudine and entecavir , and the two immune
system modulators interferon alpha-2a and PEGylated
interferon alpha-2a (Pegasys).
• The use of interferon, which requires injections daily or
thrice weekly, has been supplanted by long-acting
PEGylated interferon which is injected only once
weekly

48. Hepatitis C
• HCV is a positive stranded RNA virus
• Hepatitis C is an infectious disease affecting
primarily the liver.
• The infection is often asymptomatic, but chronic
infection can lead to scarring of the liver and
ultimately to cirrhosis.
• In some cases, those with cirrhosis will go on to
develop liver failure, liver cancer or life-threatening
esophageal and gastric varices.

49. • HCV is spread primarily by blood-to-blood
contact associated with intravenous drug use,
poorly sterilized medical equipment
and transfusions.

50. Epidemiology
It is estimated that 150–200 million people, or
3% of the world's population, are living with
chronic hepatitis C. About 3–4 million people
are infected per year, and more than 350,000
people die yearly from hepatitis C-related
diseases.

51. • The incubation period is in the range of 1 to
26 weeks and only about 5% of acute HCV
infection is associated with signs and
symptoms of acute hepatitis.

52. Signs and symptoms
Acute infection:
• decreased appetite
• fatigue
• nausea
• muscle or joint pains,
• weight loss and
• rarely acute liver failure
• jaundice

53. Chronic infection:
Fatigue and mild cognitive problems
Fatty liver
Cirrhosis
Hepatocellular carcinoma
Ascites
Easy bruising or bleeding
varices (enlarged veins)
Hpatic encephalopathy

54. Investigation
• HCV antibody enzyme immunoassay or
ELISA, recombinant immunoblot assay, and
quantitative HCV RNA polymerase chain
reaction(PCR)

55. Treatment
As of 2010, treatments consist of a combination
of pegylated interferon alpha and the antiviral
drug ribavirin for a period of 24 or 48 weeks
Hepatitis C is a common reason for liver
transplantion