Needle-stick injuries

Question 1

how do you evaluate risk of transmission of any infection from a contaminated source

Answer 1

evaluate risk of infection in the source patient by history and serologic testing

Question 2

what is the risk of infection of the below via percutaneous injury (needle stick):
HBV

Answer 2

6-30%

Question 3

what is the risk of infection of the below via percutaneous injury (needle stick):
HCV

Answer 3

1.8%

Question 4

what is the risk of infection of the below via percutaneous injury (needle stick):
HIV

Answer 4

0. 3%

* risk from mucous membrane contact is 0.09%

Question 5

risk factors for HBV transmission

Answer 5

non immune

source patient is HBeAG positive

Question 6

what body fluids are documented to transmit HBV

Answer 6

blood and blood products

semen, vaginal secretions and saliva can potentially transmit the virus

non bloody urine and feces are unlikely to transmit

Question 7

what type of post exposure prophylaxis is offered in the case of possible HBV transmission/needle stick

Answer 7

if affected person is unvaccinated: 1x HBIG within 24 hours and primary vaccination within 7 days

if vaccinated and anti-HbsAG titer above 10mIU/mL–no treatment

if vaccinated and anti-HbsAg titer less than 10 then treat as if unvaccinated

if vaccinated, titer is unknown but known response to previous vaccine, then give 1 booster dose of vaccine

if vaccinated but no response to previous vaccine, give 2 doses of HBIG one month apart or initiate revaccination and 1 dose of HBIG

Question 8

what is the efficacy of prophylaxis for HBV

Answer 8

HBIG + vaccine–85-95%
vaccine alone–70-95%
multiple doses of HBIG–70-75%

Question 9

what follow up should be offered in the case of exposure to HBV/needle stick

Answer 9

minimal risk of transmission to patients, household contacts and sexual partners for those that receive prophylaxis

test for anti-HbsAg 1-6 months post vaccination

Question 10

is there any proven post exposure prophylaxis for HCV blood or contaminated body fluids

Answer 10

no

immunoglobin and antiviral agents are NOT recommended in post exposure prophylaxis of HCV

the post exposure use of interferon (1-3 days of therapy initiated 1-12 days after exposure) has not been documented to reduce the rate of infection

Question 11

what is the recommended follow up for HCV exposure/needle stick

Answer 11

baseline testing for anti-HCV, HCV RNA and ALT

follow up testing for HCV RNC between 4-5 weeks after exposure

follow up testing for anti-HCV, HCV RNA and ALT 4-6 months after exposure

• if anti-HCV titers are negative, there exists only a 10% chance of infection
• if anti-HCV titers are positive, 50% can go on to develop chronic hepatitis so may benefit from treatment with interferon alpha
• should avoid unprotected sex until follow up testing is complete however little evidence to suggest that sexual transmission of HCV is problematic

Question 12

risk factors for transmission of HIV

Answer 12

large volume of inoculate

increased titer of HIV (early and late disease)

deep injury

a device visibly contaminated with the patients blood

needle placement in a vein or artery

termina illness in the source patient

Question 13

initial actions to take following exposure/needle stick in case of HIV risk

Answer 13

skin–> immediate cleansing with soap, water, antiseptics like alcohol or chlorhexidine

mucosal membrane–> copious amounts of water

eyes–> saline or water

post exposure prophylaxis depending on type of exposure

Question 14

how do you decide whether to do PEP

Answer 14

must weigh risk of infection with HIV against toxicity and inconvenience of PEP

individual preferences of the exposed HCW will generally determine the decision

• all known seroconversions have occurred with exposure to blood, bodily fluids, or viral culture –> contamination of intact skin with body fluids is not considered an exposure and PEP is not required
• CDC recommends that PEP should be based on whether the exposure is percutaneous or to mucous membranes or non intake skin, and take into account the likelihood the source is HIV infected and the stage of HIV infection

Question 15

what is PEP for HIV

Answer 15

2 NRTIs for lower risk exposure and the addition of a boosted protease inhibitor for higher risk exposures–> take them for 4 weeks

• initiation should not be delayed for pending determination of source status
• offer PEP up to 24-36 hours after exposure; start PEP 1-2 hours or earlier post exposure

Question 16

exposures to what kind of HIV source would warrant the expanded 3 drug PEP in a percutaneous injury/needle stick

Answer 16

symptomatic HIV infection, AIDS, acute seroconversion patients or known high viral load

Question 17

how do you follow up a possible HIV exposure/needle stick

Answer 17

monitor for drug toxicity from PEP with CBC biweekly, renal and LFTS biweekly and if you are on the expanded 3 drug regimen, monitor hyperglycemia

monitor for anti-HIV at baseline, 6 weeks, 3 months, 6 months post exposure
–> negative result at 6 months implies lack of transmission

Question 18

how do you counsel people exposure to HIV about sex

Answer 18

protected sex until 6 month testing is complete

Question 19

what do you have to remember when counselling after a possible HIV exposure/needle stick

Answer 19

mental health issues