HIV post exposure - an important regimen . used info,prepared in 2010. guidelines have changed since then. Advised to refer WHO guidelines. Undergraduate level exam prep

1. HIV-Post-Exposure Prophylaxis andHIV-Post-Exposure Prophylaxis and
Prevention of Vertical TransmissionPrevention of Vertical Transmission
- R.Malarvizhi- R.Malarvizhi

2. Where did HIV come from?Where did HIV come from?

Scientists identified a type of chimpanzeeScientists identified a type of chimpanzee
in West Africa as the source of HIVin West Africa as the source of HIV
infection in humans.infection in humans.

Simian immunodeficiency virus or SIV)Simian immunodeficiency virus or SIV)
most likely was transmitted to humansmost likely was transmitted to humans
by mutation when humans came inby mutation when humans came in
contact with infected animal bloodcontact with infected animal blood

Over decades, the virus slowly spreadOver decades, the virus slowly spread
across Africa and later into other parts ofacross Africa and later into other parts of
the worldthe world

3. How will we achieve universalHow will we achieve universal
access?access?
UNAIDS -identified nine priority areas forUNAIDS -identified nine priority areas for
its support to countries to achieve theirits support to countries to achieve their
universal access targets. These areas willuniversal access targets. These areas will
contribute directly to both thecontribute directly to both the
achievement of universal access and willachievement of universal access and will
simultaneously enable advancement tosimultaneously enable advancement to
the millennium Development goals.the millennium Development goals.

4.  Reducing sexual transmission of HIVReducing sexual transmission of HIV
 Preventing mothersPreventing mothers fromfrom dying and babies fromdying and babies from
becoming infected with HIVbecoming infected with HIV
 Ensuring that people living with HIV receive treatmentEnsuring that people living with HIV receive treatment
 Preventing people living with HIV from dying ofPreventing people living with HIV from dying of
tuberculosistuberculosis
 Protecting drug users from becoming infected with HIVProtecting drug users from becoming infected with HIV
 Removing punitive laws, policies, practices, stigma andRemoving punitive laws, policies, practices, stigma and
discrimination that block effective responses to AIDSdiscrimination that block effective responses to AIDS
 Empowering young people to protect themselves fromEmpowering young people to protect themselves from
HIVHIV
 Stopping violence against women and girlsStopping violence against women and girls
 Enhancing social protection for people affected by HIVEnhancing social protection for people affected by HIV

5. Role of Pathogenesis in Considering AntiretroviralRole of Pathogenesis in Considering Antiretroviral
ProphylaxisProphylaxis
 Systemic infection does not occur immediately, leaving a briefSystemic infection does not occur immediately, leaving a brief
windowwindow of opportunity during which postexposure antiretroviralof opportunity during which postexposure antiretroviral
intervention might modify or prevent viral replication.intervention might modify or prevent viral replication.
 In a primate model of simian immunodeficiency virus (SIV) infection,In a primate model of simian immunodeficiency virus (SIV) infection,
infection of dendritic-like cellsinfection of dendritic-like cells occurred at theoccurred at the site of inoculationsite of inoculation
during theduring the first 24 hoursfirst 24 hours following mucosal exposure to cell-freefollowing mucosal exposure to cell-free
virus.virus.
 Over theOver the subsequent 24--48 hourssubsequent 24--48 hours, migration of these cells to, migration of these cells to
regional lymph nodesregional lymph nodes occurred, and virus was detectable in theoccurred, and virus was detectable in the
peripheral blood within 5 daysperipheral blood within 5 days
 Theoretically, initiation of antiretroviral PEP soon after exposureTheoretically, initiation of antiretroviral PEP soon after exposure
might prevent or inhibit systemic infection by limiting the proliferationmight prevent or inhibit systemic infection by limiting the proliferation
of virus in the initial target cells or lymph nodes.of virus in the initial target cells or lymph nodes.

6. WHEN TO TAKEWHEN TO TAKE
 Blood and visibly bloody body fluids,Blood and visibly bloody body fluids,
 Semen, and vaginal secretions.Semen, and vaginal secretions.
 Compartment fluidsCompartment fluids

Cerebrospinal fluid,Cerebrospinal fluid,

synovial fluid,synovial fluid,

pleural fluid,pleural fluid,

peritoneal fluid, pericardial fluid, andperitoneal fluid, pericardial fluid, and

amniotic fluidamniotic fluid
( the transmission risk associated with them is less well defined)( the transmission risk associated with them is less well defined)
 Feces, nasal secretions, saliva, sputum, sweat, tears,Feces, nasal secretions, saliva, sputum, sweat, tears,
urine, and vomitus when mixed with bloodurine, and vomitus when mixed with blood
 Exposures that pose a risk for transmissionExposures that pose a risk for transmission
percutaneous injuries, contact of mucous membranes, orpercutaneous injuries, contact of mucous membranes, or
contact of non-intact skin with potentially infected fluicontact of non-intact skin with potentially infected flui

7. HIV-PEPHIV-PEP
 UN-AIDSUN-AIDS

NON-OCCUPATIONALNON-OCCUPATIONAL

OCCUPATIONALOCCUPATIONAL

8. NON-OCCUPATIONALNON-OCCUPATIONAL
 To Prevent Infection with Hepatitis BTo Prevent Infection with Hepatitis B
Virus, Hepatitis C Virus, or HumanVirus, Hepatitis C Virus, or Human
Immunodeficiency Virus, and TetanusImmunodeficiency Virus, and Tetanus
in Persons Wounded During Bombingsin Persons Wounded During Bombings
and Other Mass-Casualty Eventsand Other Mass-Casualty Events

9.  Risk categoryRisk category

Penetrating injuries orPenetrating injuries or
non-intact skinnon-intact skin
exposuresexposures

Mucous membraneMucous membrane
exposureexposure

Superficial intact skinSuperficial intact skin
exposureexposure
 HIVHIV

Generally no actionGenerally no action

Generally no actionGenerally no action

No actionNo action

11.  If PEP is administered, the health-care providerIf PEP is administered, the health-care provider
also should obtain baseline complete bloodalso should obtain baseline complete blood
count, renal function, hepatic function tests, and,count, renal function, hepatic function tests, and,
in women, a pregnancy test.in women, a pregnancy test.
 Efavireniz might be teratogenic, it should not beEfavireniz might be teratogenic, it should not be
administered until pregnancy test results areadministered until pregnancy test results are
available . Otherwise, test results need not beavailable . Otherwise, test results need not be
available before PEP initiation but should beavailable before PEP initiation but should be
reviewed in follow-up.reviewed in follow-up.

12. OCCUPATIONALOCCUPATIONAL

Emphasizes prompt management of occupationalEmphasizes prompt management of occupational
exposures, selection of tolerable regimens, attentionexposures, selection of tolerable regimens, attention
to potential drug interactions involving drugs thatto potential drug interactions involving drugs that
could be included in HIV PEP regimenscould be included in HIV PEP regimens

13.  HCP refers to all paid and unpaid persons working inHCP refers to all paid and unpaid persons working in
health-care settings who have the potential for exposurehealth-care settings who have the potential for exposure
to infectious materials include,to infectious materials include,

emergency medical service personnel,emergency medical service personnel,

dental personnel, laboratory personnel,dental personnel, laboratory personnel,

autopsy personnel,autopsy personnel,

nurses, nursing assistants,nurses, nursing assistants,

physicians,physicians,

technicians, therapists, pharmacists,technicians, therapists, pharmacists,

students and trainees,students and trainees,

contractual staff not employed by the health-care facility, andcontractual staff not employed by the health-care facility, and

persons not directly involved in patient care but potentiallypersons not directly involved in patient care but potentially
exposed to blood and body fluids (e.g., clerical, dietary,exposed to blood and body fluids (e.g., clerical, dietary,
housekeeping, maintenance, and volunteer personnel).housekeeping, maintenance, and volunteer personnel).
 VolunteersVolunteers

14. WHOWHO
 Recommended the use of HAARTRecommended the use of HAART
regimens for all significant-riskregimens for all significant-risk
occupational exposures when the HCWoccupational exposures when the HCW
is evaluatedis evaluated within 36 hourswithin 36 hours ofof
exposure.exposure.

15. WHO recommendations onWHO recommendations on
treatmenttreatment
 Minimum that should be used is dual NRTIs forMinimum that should be used is dual NRTIs for
28 days, with triple therapy (dual NRTIs plus a28 days, with triple therapy (dual NRTIs plus a
boosted PI) being offered where there is a risk ofboosted PI) being offered where there is a risk of
resistanceresistance
 The effectiveness of this intervention has neverThe effectiveness of this intervention has never
been precisely ascertained, but postexposurebeen precisely ascertained, but postexposure
prophylaxis is most effective when administeredprophylaxis is most effective when administered
sooner, though not believed to be effective ifsooner, though not believed to be effective if
givengiven 72 hours72 hours after exposure.after exposure.

17. Prevention of vertical transmissionPrevention of vertical transmission
 Mother-to-child transmission of HIVMother-to-child transmission of HIV
 A woman infected with humanA woman infected with human
immunodeficiency virus (HIV), canimmunodeficiency virus (HIV), can
transmit the virus to her child duringtransmit the virus to her child during

pregnancy,pregnancy,

labour or delivery,labour or delivery,

through breastfeeding.through breastfeeding.

18. Current WHO recommendedCurrent WHO recommended
regimenregimen
 Where the pregnant woman does not yetWhere the pregnant woman does not yet
need to start ART for therapeutic reasons,need to start ART for therapeutic reasons,
she should startshe should start

Zidovudine (AZT) from 28 weeks or as soonZidovudine (AZT) from 28 weeks or as soon
as possible thereafter,as possible thereafter,

be provided with single-dose Nevirapinebe provided with single-dose Nevirapine
(NVP) when entering labour, and(NVP) when entering labour, and

be given AZT+3TC for one week followingbe given AZT+3TC for one week following
delivery.delivery.

19.  Meanwhile, whether the mother was onMeanwhile, whether the mother was on
the above or standard ART,the above or standard ART,

child should be given single dose Nevirapinechild should be given single dose Nevirapine
immediately after delivery andimmediately after delivery and

daily Zidovudine until one week olddaily Zidovudine until one week old

20.  Complementary measures that may alsoComplementary measures that may also
be used includebe used include

caesarian section and formula feeding;caesarian section and formula feeding;

in some settings, the combination ofin some settings, the combination of
providing all these measures has succeededproviding all these measures has succeeded
in reducing the risk of infection from 25% toin reducing the risk of infection from 25% to
about 1%.about 1%.

22.  PEP Drugs to Avoid DuringPEP Drugs to Avoid During
PregnancyDrug(s) to AvoidToxicityPregnancyDrug(s) to AvoidToxicity

Efavirenz-TeratogenicityEfavirenz-Teratogenicity

Combination of stavudine and didanosine-Combination of stavudine and didanosine-
Mitochondrial toxicityMitochondrial toxicity

Unboosted IDV in the 2nd or 3rd trimester-Unboosted IDV in the 2nd or 3rd trimester-
Substantially lower antepartum indinavirSubstantially lower antepartum indinavir
plasma concentrationsplasma concentrations

23. WHOWHO
 Develop or revise (as the case may be) a comprehensiveDevelop or revise (as the case may be) a comprehensive nationalnational
policy on infant and young child feedingpolicy on infant and young child feeding which includes HIV andwhich includes HIV and
infant feedinginfant feeding
 Implement and enforce the International Code of Marketing ofImplement and enforce the International Code of Marketing of
Breast-milk SubstitutesBreast-milk Substitutes and subsequent relevant WHA resolutionsand subsequent relevant WHA resolutions
 Intensify efforts to protect, promote and support appropriate infantIntensify efforts to protect, promote and support appropriate infant
and young child feeding practices in general, while recognizing HIVand young child feeding practices in general, while recognizing HIV
as one of a number of exceptionally difficult circumstancesas one of a number of exceptionally difficult circumstances
 ProvideProvide adequate support to HIV-positive womenadequate support to HIV-positive women to enable them toto enable them to
select the best feeding option for themselves and their babies and toselect the best feeding option for themselves and their babies and to
successfully carry out their infant feeding decisionssuccessfully carry out their infant feeding decisions
 Support research on HIV and infant feedingSupport research on HIV and infant feeding – including operations– including operations
research, learning, monitoring and evaluation at all levels – andresearch, learning, monitoring and evaluation at all levels – and
disseminate findings.disseminate findings.

24. ReferenceReference
 www.unaids.orgwww.unaids.org
 www.cdc.gov/mmwrwww.cdc.gov/mmwr
 http://http://
www.who.int/hiv/pub/guidelines/PEP/enwww.who.int/hiv/pub/guidelines/PEP/en//
 Mudaliar Textbook of ObstetricsMudaliar Textbook of Obstetrics
 Park Textbook of Social and PreventivePark Textbook of Social and Preventive
MedicineMedicine
 Harrison Textbook of Internal MedicineHarrison Textbook of Internal Medicine