Bloodborne

Pathogens

ENVH 451/541

November 12, 2008

Bloodborne Pathogens (BBPs)

Other Potentially Infectious Materials

Present in

Blood or

Bloodborne Pathogens• semen

• vaginal secretions

• body fluids such as pleural, cerebrospinal, pericardial, peritoneal, synovial, and amniotic

• saliva in dental procedures (if blood is present)

• any body fluids visibly contaminated with blood

• body fluid where it is difficult to differentiate

• any unfixed tissue or organ (other than intact skin) from a human (living or dead)

• HIV- or HBV-containing cultures (cell, tissue, or organ), culture medium, or other solutions

• blood, organs, & tissues from animals infected with HIV, HBV, or BBPs

OPIM

2 Methods of Entry:

• Mucocutaneous– Enters through mucus membranes

• Percutaneous– Enters through some opening of the skin

Mucocutaneous (through a mucous membrane))

• Having infected blood or other body fluids splashed into eyes, nose or mouth

Modes of Transmission

Percutaneous (through the skin)

• Being stuck with needles or other sharps

• Having infected blood or other body fluids splashed onto skin that is cut, scratched, has sores or rashes or other skin conditions

Modes of Transmission

Bloodborne Pathogen Diseases

Some examples of bloodborne pathogens:

• Malaria • Syphilis • Brucellosis• Leptospirosis

• Arboviral infections • Relapsing fever • Creutzfeld-Jakob Disease • Viral Hemorrhagic Fever

• Ebola, Marburg

Primary Pathogens of Concern:

• Hepatitis B Virus (HBV)• Hepatitis C Virus (HCV)• Human Immunodeficiency Virus (HIV)

HIV

A global view of HIV infection33 million people [30–36 million] living with

HIV, 2007

HIV/AIDS in King CountyHIV/AIDS in King County

• HIV - 2,773

• AIDS - 3,532

• HIV/AIDS -

6,305

HIV/AIDS Prevelence by Exposure

69%

5%

8%

1%

10%

0%7%

MSM

Heterosexual

Blood Exposure

Perinatal

MSM & IDU

Undetermined

IDU

HIV and AIDS

The CDC defines AIDS as a positive HIV test and one of the following:

•The development of an opportunistic infection – an infection that occurs when your immune system is impaired

•A CD4 lymphocyte count of 200 or less –a normal count ranges from 800 to 1,200– directly attack and kill invading cells

Natural History of Infection

Symptoms

• Immediately following infection– Nonspecific “viral illness”

• Low grade fever, rash, muscle aches, headache, fatigue

• Resolve in 5-10 days

• Asymptomatic– Immune system is cycling with CD4 cells

• AIDS– Extreme fatigue, rapid weight loss, swollen lymph

nodes, dry cough and shortness of breath, night sweats

Management

• No “cure”

• HAART– “cocktail” of 3 -4 AR drugs– Difficult: complex regimes,

severe side effects, compliance very important

• Diarrhea, vomiting, nausea, headache, blurred vision, dizziness, congestion, dry mouth, fatique, body ache, fever, rash, sores, feeling loss, difficulty sleeping, changing body shape, hair loss, dry skin, etc.

HIV IN BLOOD

• SURVIVAL OUTSIDE THE BODY– In dry blood the virus can survive for up to 6 days in

laboratory conditions

• QUANTITY OF VIRUS IN BLOOD– 1 mL of blood contains 200-10,000 particles of virus.

• RISK OF INFECTION FOLLOWING NEEDLE STICK INJURY – Low - 0.3% - 3 people in 1,000.

• RISK OF INFECTION FOLLOWING EYE SPLASH– Low - 0.09%

* Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis. MMWR Recommendations and Reports, June 29, 2001 / 50(RRll);1-42. Centers for Disease Control and Prevention

Hepatitis C

Global Burden of HCV

Hepatitis C Symptoms

• flu-like symptoms

• jaundice

• fatigue

• dark urine

• abdominal pain

• loss of appetite

• nausea

US HCV Infection• Incubation period Average 6-7

weeksRange 2-26

weeks

• Acute illness (jaundice) Mild (<20%)

• Case fatality rate Low 8-10 K

• Chronic infection 60%-85% 2.7M people

• Chronic hepatitis 10%-70%

• Cirrhosis <5%-20%

• Mortality from CLD 1%-5%

Source: Sentinel Counties, CDC

Sources of Infection forPersons With Hepatitis C

Sexual 15%

Other 1%*

Unknown 10%

Injecting drug use 60%

Transfusion 10%(before screening)

* Nosocomial; iatrogenic; perinatal

Occupational 4%

Occupational Transmission

• Inefficient by occupational exposures

• Incidence 1.8% following needle stick from HCV-positive source – Associated with hollow-bore needles

• Prevalence 1-2% among health care workers – Lower than adults in the general population– Most appear related to HCW substance abuse– No restrictions routinely recommended for HCV-

infected HCWs

Perinatal Transmission of HCV

• Transmission only from women HCV-RNA positive at delivery– Average rate of infection 6%– Higher (17%) if woman co-infected with

HIV– Role of viral titer unclear

• No association with– Delivery method– Breastfeeding

• Infected infants do well– Severe hepatitis is rare

HEPATITIS C IN BLOOD

• SURVIVAL OUTSIDE THE BODY– Little is known but likely to be the same as hepatitis B, up to 10 days

• QUANTITY OF VIRUS IN BLOOD– 1 mL of blood contains 1,000 - 10,000 particles of virus

• RISK OF INFECTION FOLLOWING NEEDLE STICK INJURY – Medium - 3% - 3 people in 100

• RISK OF INFECTION FOLLOWING EYE SPLASH– Low

* Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis. MMWR Recommendations and Reports, June 29, 2001 / 50(RRll);1-42. Centers for Disease Control and Prevention

Hepatitis B

Hepatitis BSymptoms• flu-like symptoms

• fatigue

• abdominal pain

• loss of appetite

• nausea, vomiting

• joint pain

• jaundice

Incubation• 60-120 days following

infection

Duration• Several weeks to

months

Global Distribution of HBV

8% - High

Global Patterns of Chronic HBV Infection

• High (>8%): 45% of global population– lifetime risk of infection >60%– early childhood infections common

• Intermediate (2%-7%): 43% of global population– lifetime risk of infection 20%-60%– infections occur in all age groups

• Low (<2%): 12% of global population– lifetime risk of infection <20%– most infections occur in adult risk groups

Hepatitis B Incidence

Blood transfusion 0%

Other* 15%

Unknown 32%

Hemodialysis 0%Multiple sex partners 17%

Injection drug use 14%

Men who have sex with men 6%

Sexual contact with hepatitis B patient 13%

Medical Employee 1%

Household contact of hepatitis B patient 2%

Risk Factors Associated with Reported Hepatitis B, 1990-2000,

United States

Source: NNDSS/VHSP *Other: Surgery, dental surgery, acupuncture, tattoo, other percutaneous injury

Transmission of HBV

• Concentration of HBV in various body fluids– High: Blood, serum, wound exudates– Medium: saliva, semen, and vaginal secretions– Low/not detectable: urine, feces, sweat, tears,

breastmilk

• Household transmission – less risk than percutaneous but significant - can occur in settings such as shared toothbrushes, razors, combs, washcloths

Transmission of HBV

• Likelihood of becoming a carrier varies inversely with the age at which infection occurs.

• Pool of carriers in U.S. is 1-1.25 million persons.

• ~5000 persons die/yr. from HBV-related cirrhosis.

Prevention & Treatment

• “Advisory Committee on Immunization Practices (ACIP) recommends that all children receive their first dose of hepatitis B vaccine at birth and complete the vaccine series by age 6–18 months” (CDC)

– Adults where deficient

• Acute Infection– no medication is available; treatment is supportive

• Chronic Infection– several antiviral drug – require regular monitoring to determine whether

disease is progressing and to identify liver damage or hepatocellular carcinoma.

HEPATITIS B IN BLOOD

• SURVIVAL OUTSIDE THE BODY– In dry blood the virus can survive for up to 10 days

• QUANTITY OF VIRUS IN BLOOD– 1 mL of blood contains 100,000,000 particles of virus

• RISK OF INFECTION FOLLOWING NEEDLE STICK INJURY– Very High - 30% - 3 people in 10

• RISK OF INFECTION FOLLOWING EYE SPLASH– High.

* Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis. MMWR Recommendations and Reports, June 29, 2001 / 50(RRll);1-42. Centers for Disease Control and Prevention

Occupational Exposure

• means reasonably anticipated skin, eye, mucous membrane, or parenteral (piercing of the skin) contact with blood or OPIM that may result from the performance of an employee's duties

Occupational Exposure

Transmission of BBPs

• is a specific contact with blood or OPIM that is capable of transmitting a bloodborne disease

Exposure Incident

Most Common Occupational Exposure

Needlestick Injuries

Over 85% of documented occupational transmissions

Health Care Workers and Bloodborne Pathogens

• HBV: 6%-30%

• HCV: 1.8% (range 0%-7%)

• HIV: 0.3%

Occupational Transmission

Risk of infection following needlestick/cut from a positive (infected) source:

Transmission of BBPs

Risk of infection depends on several factors:

The pathogen involved The type/route of exposure The amount of virus in the

infected blood at the time of exposure

The amount of infected blood involved in the exposure

Whether post-exposure treatment was taken

Specific immune response of the infected individual

Courtesy of Owen Mumford, Inc.

Health Care Workers and BBPs

• Most common: needlesticks

• Cuts from other contaminated sharps (scalpels, broken glass, etc.)

• Contact of mucous membranes (eye, nose, mouth) or broken (cut or abraded) skin with contaminated blood

Occupational TransmissionCauses of percutaneous injuries with hollow-

bore needles, by % total percutaneous injuries

Manipulating needle in patients

27%

IV line-related causes

8%

Handling or passing device

during or after use

10%

Recapping

5%

Clean-up

11%

Collision w/health

care worker or sharp

8%

Disposal-related causes

12%

Improperly disposed

sharp10%

Handling/transferring specimens

5%

Other4%

Source: CDC [1999]

Exposure Controls

• Universal precautions (or equivalent system*)

• Equipment and Safer Medical Devices

• Work practices

• Personal protective equipment

• Housekeeping

• Laundry handling

• Hazard communication- labeling

• Regulated Waste

Occupational Exposure Protection

Exposure Controls

Protected position

Unprotected position

Universal Precautions

• A system of infection control in

which all human blood and OPIM

are treated as if known to be

infectious with a bloodborne

disease.