Infection

Modes of Transmission

Estimated transmission risk to a susceptible host

Primary risk reduction strategies

Staff to patient

Chickenpox, disseminated zoster

Contact with vesicles; droplet or airborne spread from respiratory tract of acute casesand perhaps from disseminated zoster.

High

High

Varicella vaccine for susceptible individuals; varicella zoster immune globulin (VZIG) for immunocompromised contacts of cases. Major risk: adults and immunocompromised hosts; bone marrow transplant patients at greatest risk.

Conjunctivitis, viral (e.g., adenovirus)

Contact with eye secretions and contaminated objects.

High

High

Identify and eliminate environmental reservoirs; restrict infected personnel; emphasise hand hygiene and disinfection of shared ophthalmic equipment.

Cytomegalovirus (CMV)

Contact with urine, saliva, breast milk, cervical secretions, and semen from infected person who is actively shedding virus.

Rare

Use appropriate gloves and hand hygiene in handling diapers and oral secretions. CMV is very common in young children, organ-transplant patients, and patients with HIV/AIDS; undiagnosed cases are far more common than diagnosed cases.

Hemorrhagic fever

(Ebola & Marburg virus)

Bloodborne; some question of contact transmission.

Low

Moderate (risk from puncture unknown)

Bloodborne disease precautions: safe handling of needles and sharps; use gloves, other barriers including protective eyewear, and hand hygiene.

Hepatitis A

Person-to-person by fecal-oral route; rarely via blood transfusion; infected foodhandlers with poor personal hygiene can contaminate food.

Rare

Rare

Use care in handling diapers and fecal materials; use gloves and hand hygiene appropriately; use immune serum globulin prophylaxis for significant exposures; hepatitis A vaccine, when appropriate. Hospital outbreaks are almost always from an unrecognised case.

Hepatitis B virus

Via percutaneous, mucosal, and nonintact skin contact with blood, semen, vaginal secretions, and bloody fluids.

Low

Moderate (risk from puncture: 6-35%)

Hepatitis B vaccine for all personnel at risk for blood exposure; emphasise safe handling of needles and sharps; use gloves, other barriers, and hand hygiene appropriately; use high titer hepatitis B immune globulin (HBIG) prophylaxis for significant exposures in susceptible personnel

Hepatitis C virus

Same as for Hepatitis B.

Rare

Low

(risk from puncture: 1-7%)

Emphasise safe handling of needles and sharps; use gloves, other barriers, and hand hygiene appropriately

Herpes simplex

Contact with virus in saliva of carriers; contact with vesicle fluid.

Rare

Low

To protect personnel, use gloves for contact with oral secretions, mouth care and vesicles; to protect patients employee should cover lesion with dressing or wear gloves with herpetic whitlow. May need to restrict infected staff from patient contact.

Human immunodeficiency virus (HIV)

Primarily via percutaneous contact with blood; mucosal and nonintact skin contact with blood. Semen, vaginal secretions, and bloody body fluids less likely to transmit.

Very rare

Rare (risk from puncture: 0.03%)

Emphasise safe handling of needles and sharps; use gloves, other barriers, and hand hygiene appropriately. Manage post-exposure prophylaxis in accord with current guidelines. Healthcare workers who know or suspect themselves to be HIV or Hepatitis B e-antigen positive should seek advice ; it may not be appropriate to perform exposure-prone procedures.

Influenza

Airborne; direct or droplet contact with respiratory secretions.

Moderate

Moderate

Influenza vaccine for high-risk employees and patients; amantadine prophylaxis for influenza A exposures, as appropriate.

Measles

Airborne; direct or droplet contact with nasal or throat secretions of infected person.

High

High

Natural immunity or measles vaccine for health care personnel; vaccine for patients, as appropriate. Measles outbreaks have been reported in poorly-ventilated medical offices; many health care facilities require measles immunity as a condition of employment.

Meningococcal infection

Direct contact with oral secretions.

None reported

Rare

Appropriate use of gloves and hand hygiene; antibiotic prophylaxis indicated only for personnel with mucosal contact with oral secretions (e.g., performing mouth-to-mouth resuscitation).

Mumps

Droplet contact or direct contact with oral secretions.

Moderate

Moderate

Mumps vaccine is effective for personnel and patients; adults may have complications.

Pertussis

Droplet contact or direct contact with respiratory secretions.

Moderate

Moderate

Appropriate use of gloves, other barriers, and hand hygiene; antibiotic prophylaxis of exposed health care workers; hospital outbreaks reported.

Respiratory syncytial virus

Droplet contact or direct contact with respiratory secretions.

Moderate

Moderate

Appropriate use of gloves, other barriers, and hand hygiene; eye protection may reduce risk of self-inoculation via contaminated hands.

Rotavirus

Person-to-person via fecal-oral route.

Moderate

Moderate

Appropriate use of gloves, other barriers, and hand hygiene; many outbreaks have been reported in adult and child units.

Rubella

Droplet contact or direct contact with respiratory secretions: airborne transmission not demonstrated.

Moderate

Moderate

Natural immunity or rubella vaccine for health care personnel and vaccine for patients, as appropriate. Many health care facilities require employees to be immune to rubella.

Salmonella or Shigella

Person-to-person via fecal-oral route; via contaminated food or water; foodhandlers with poor personal hygiene can contaminate food.

Low

Low

Hand hygiene, especially after using the toilet and before preparing food; appropriate use of gloves and hand hygiene when caring for incontinent patients. Shigella requires only a very small inoculum (10 - 100 organisms) and is easy to transmit; Salmonella requires larger inoculum and is common in eggs and poultry.

Scabies

Direct skin-to-skin contact with infested person.

Low

Low

Index of suspicion for scabies with any undiagnosed rash; use of scabicide promptly to eradicate infestation; gloves, other barriers, and hand washing. Outbreaks have often involved patients, personnel and household contacts.

Staphylococcus aureus

(includes wound and skin infection)

Direct and indirect contact.

Rare

No data

Appropriate use of gloves, other barriers and hand hygiene. S. aureus intermittently colonises normal human skin and the nares of 2 - 30% of the population. Transmission from patient to patient common. Treatment to eradicate colonisation is controversial.

Streptococcus, Group A

Droplet contact or direct contact with oral secretions or drainage from infected wounds.

Rare

No data

Appropriate use of gloves, other barriers and hand hygiene; antibiotic treatment for symptomatic persons or those identified as shedders.

Syphilis

Direct contact with lesions of primary or secondary syphilis.

No data

Rare

Appropriate use of gloves when touching any lesions; other barriers as appropriate; hand hygiene.

Tuberculosis (TB)

Airborne transmission from sources with active pulmonary or laryngeal tuberculosis; susceptible person must inhale airborne droplet nuclei to become infected.

Low to high

Low to high

Index of suspicion for a TB case; appropriate ventilation of locations where TB patients receive care; airborne precautions for identified cases; respiratory protection for personnel. Exposure management and treatment of individuals with new infections.