Post exposure prophylaxis (pep) -by Dr Munawar Khan SACP
POST-EXPOSURE PROPHYLAXIS (PEP) Dr. M. MUNAWAR KHAN BCC Coordinator Sindh AIDS Control Program
Transmission• The risk of HIV transmission is present if an HIV-negative person comes into contact with the blood, semen or vaginal fluids of an HIV- positive source person. But exposure of intact skin to HIV-contaminated body fluids (e.g. Blood) is not sufficient to transfer the virus.
Transmission is possible if HIV-containing material enters the body• Accidental needle stick injury or incision by surgical instruments• Exposure of damaged skin or mucosal membranes• Unprotected sexual intercourse with an infected person• IDU sharing needle or equipment• Transfusion of HIV-contaminated blood or blood products
Transmission risk• HIV is not a very contagious pathogen. The transmission rate after contact is about 1:1000 to 1:100. Compared with HIV, the transmission rate for hepatitis C is 10 times higher, and 100 times higher for hepatitis B.• Contact with body fluids of a patient with a high viral load supposedly holds a higher risk of contagion than with a suppressed viral load. Additionally, quick removal of infectious material e.g. from damaged skin or mucosal membrane by washing or disinfection presumably decreases the risk of an HIV infection.• For percutaneous contact with HIV-containing blood, an infectiousness of 0.3 % in total is assumed.
Effectiveness and limitations of PEP• Early reports on the use of AZT after occupational needle stick injuries date from 1989. An analysis of retrospective case-control studies shows that even prophylaxis with a single substance after exposure reduces the probability of an infection by approximately 80 % . The combination of multiple drugs is supposedly even more potent.
When is PEP indicated• It is important to ascertain whether the source person has a supposed or confirmed HIV infection. Unclear HIV status should be clarified , the source person should be asked for consent to perform HIV testing. But denial of consent has to be respected. If the source person agrees to be tested, it should be performed immediately.
• For source persons with confirmed HIV infection, the actual HIV viral load, stage of disease, former and current HAART have to be taken into consideration. Optimally, a resistance analysis would also be available. The affected person should be asked about the first aid procedures that have already been performed. After clarification of these queries, the exposed person has to be informed about possible risks of pharmaceutical PEP
Potential risks of PEP• The risks of PEP mainly concern the adverse effects of the antiretroviral substances, most frequently gastrointestinal symptoms such as nausea, vomiting or diarrhea. Changes of hematology, transaminases or creatinine are also possible. Additionally, there have been reports of elevated triglycerides and cholesterol levels, and insulin resistance even in short term use of protease inhibitors .
Initial interventions• The decision about whether or not to offer PEP should be based purely on clinical considerations of risk (mentioned above). The provision of information regarding PEP should be confidential, including information about HIV testing, PEP provision and the reasons for seeking PEP. The informed consent needs to be obtained for the administration of PEP. The PEP must be initiated as soon as possible after the exposure, preferably within two hours and not later than 72 hours; PEP is believed to be most effective if initiated within 48 hours of exposure
Risk of infection(1) type of exposure (superficial or deep injury);(2) the amount of blood involved in the exposure;(3) amount of virus in patient’s blood at the time of exposure (patient’s viral load); and,(4) Whether PEP was taken within the recommended time (not later than 72 hours after exposure)
What to do after a needle stick injury(1) Wash the injured site thoroughly with soap and water (antiseptics may be used).(2) If as a result of a laboratory accident the skin is broken the wound should be cleaned and irrigated with a mild disinfectant such as Chlorhexidine with cetrimide(3) Administer post-exposure prophylaxis (PEP) for HIV, based on institutional policy after evaluation of risk.
Mucosal exposure• If there is an accidental exposure of the blood or other body fluids to mucosal surfaces (eg. mouth, nose or eyes) flush the exposed area with a large amount of water.• The splashes into the eye should be flushed using an eye wash fountain for 15-20 minutes. PEP should be initiated as soon as possible
Infectious agent Post-exposure prophylaxis• HIV Antiretroviral therapy (2-drugs or 3-drugs regimen)• HBV Hepatitis B immune globulin (HBIG) and/or hepatitis B vaccine• HCV No vaccine or chemoprophylaxis available