SPREAD OF HIV BY BLOOD TRANSFUSION

1. HIV in
Transfusion
Dr Sujay Bhowmik
RESIDENT
DEPT OF BLOOD TRANSFUSION
& IMMUNOHEMATOLOGY,
AFMC,PUNE

2. LAYOUT
Historical perspective
HIV in India
Etiological agent
Transmission
Disease burden
Morphology
Genetics
Pathophysiology
Progression
Mech of Drugs
Diagnostic modalities
Strategies of testing

3. Historical perspective

4. 5 June 1981, (CDC) reported a new clinical entity called
“Acquired Immunodeficiency Syndrome” among men having
sex with men in New York and California.
These men presented with rare Opportunistic Infections
Pneumocystis (carinii) pneumonia and Kaposi’s sarcoma.
The causative agent of AIDS was identified two years later in
1983

5. Spread in injection drug users; hemophiliacs and
blood transfusion recipients; female sexual
partners of men with AIDS; infants born to mothers
with AIDS
1985, ELISA was developed; led to an appreciation
of the scope and evolution of the HIV epidemic
1986, the International Committee on Taxonomy of
Viruses recommended a separate name , the
Human Immunodeficiency Virus (HIV).

6. In 1989 testing of donated blood for HTLV-I begins
In 1992 testing of blood for HIV-I and HIV-2 implemented
In 1996 HIV P24 antigen testing of donated blood begins

7. Nucleic acid testing (NAT) was implemented in 1999 to screen
donors for HIV and HCV RNA
In 2002 NAT for HIV and HCV was licensed by the FDA

8. HIV in INDIA

9. 1986, first case of HIV was diagnosed by Dr. Suniti Solomon and
Dr. Sellappan Nirmala amongst female sex workers in Chennai
 1987, about 135 more cases came to light.
HIV screening centers were set up by government to screen
citizens and blood products
 The government launched the National AIDS Control
Programme (NACP) in 1992, to co-ordinate blood screening and
health education.

10. 1992, the government set up National AIDS Control Organisation
(NACO) to oversee prevention and control programmes
 1999, Second phase of the National AIDS Control Programme
(NACP II) introduced.
 Prevention of mother-to-child transmission programme (PMTCT)
and the provision of antiretroviral treatment were materialized.
 2007, Third phase of the National AIDS Control Programme
(NACP III) targeted the high-risk groups, conducted outreach
programmes. Decentralised effort to local levels and (NGOs).
2012, Fourth phase of NACP , reduce new infections by 50% ,
provide comprehensive care to PLHIV

11. Etiological agent
• Family of human retroviruses (Retroviridae) , subfamily of
lentiviruses.
• Four retroviruses cause human disease belong to two
distinct groups
• HTLV-I and HTLV-II, which are transforming retroviruses
• HIV-1 and HIV-2, which cause cytopathic effects .
• The most common cause of HIV disease is HIV-1.
• HIV-2 was first identified in 1986 in West African patients

12. Common Ancestor
(STLV-I)
HTLV-I
HTLV-II
HIV-1
HIV-2
(SIV)
Transforming Viruses
Cell Proliferation
Cytopathic Viruses
Cell Death

15. Global burden of disease

19. HIV Transmission
Through
Transfusion

20. Number of cases of transfusion-transmitted HIV infection from
contaminated blood products, by transfusion - United States,
1985--2008

21. • Effective testing methods to screen donated blood has greatly
reduced the risk for transfusion transmitted HIV
• Risk for HIV from transfusion in U.S declined from one in
450,000-600,000 donations in 1995.
• To one in 2,135,000 donations from 1995 to 2001 after the
introduction of NAT in 1999.
• To one in 1,467,000 from 2007 to 2008

22. • Right to Information
(RTI) revealed that 14,474 cases of
HIV through blood transfusion have
been reported in India 2009-16
• The National AIDS Control
Organisation (NACO), reported that
around 1,342 people contracted HIV
via transmission of Blood products in
2018-19.
.
Indian scenario

23. • Risk of HIV through infected blood products exceeds that of
any other risk exposure.
• 90% of recipients transfused with HIV antibody-positive blood
are found to be HIV infected at follow-up
• HIV infectivity of red blood cell components decreases as
storage time increases.
• HIV-contaminated RBCs stored for <8 days are 96% infectious,
whereas those stored for >3 weeks are 50% infectious.
• The level of a donor's viremia at the time of donation is an
important determinant of HIV transmission risk.
Risk of Transmission

24. • HIV disease due to transfusion progresses in the recipient at
rates comparable to those in individuals infected for similar
duration but by other routes
• The mean time of progression to AIDS is estimated to be 8.2
years for adult transfusion recipients who receive no
antiretroviral therapy,
• Cumulative prevalence of 20% having AIDS 5 years after
transfusion

25. Morphology
• HIV is an enveloped virus
• Two phospholipid layers derived from the host cell
membrane.
• The envelope also contains glycoprotein (gp) 160.
• Gp160 is composed of two subunits, gp120 and gp41.
1. Gp120 has external protein , bind CD4 cells and co
receptor
2. Gp41 is membrane bound protein.

26. • Inside the viral envelope a layer called the matrix, made
from protein p17.
• Viral core (or capsid) is bullet-shaped made up of protein
p24.
• Inside the core are three enzymes required for HIV
replication: Reverse Transcriptase, integrase and protease.
• HIV genetic material which consists of two positive strands
of RNA

29. Genetics
HIV genome is approximately 9.1Kb in size
 Nine genes and long terminal repeat (LTR) regions at either
end
There are 3 structural genes that code structural proteins
1. Envelope (env) coding for : envelope
2. Group specific antigens (gag) coding for: caspid and matrix
3. DNA polymerase (pol) coding for: integrase,proteasereverse
transcriptase enzymes

30.  3 Regulatory genes : for virus replication
1. Trans activator of transcription (tat),
2. Regulator of expression of virion proteins (rev)
3. Negative factor (nef).
 3 Accessory genes : virus replication, regulation ,host-cell
maneuvers
1. viral infectivity factor (vif)
2. viral protein R (vpr)
3. viral protein unique (vpu) or vpx in the case of HIV-2.
The ends of each strand are LTR, an RNA sequence.
 Act as switches to control the production of new viruses

32. Pathophysiology

35. Disease progression

36. Mechanism of ART

37. Diagnostic modalities

38. Diagnosis
Diagnosis of HIV Infection :
1. demonstrating the presence of virus or viral products
2. detecting host response to the virus (antibodies)
Serological Tests:
1. Enzyme linked immunosorbent assays (ELISA)
2. Rapid tests
3. Western blots
4. Chemiluminescence Immunoassays (CIA),
5. Immuno Florescent Assays
6. Line Immunoassays

39. Rapid tests are:
1. Immunoconcentration/Dot Blot assay (vertical flow)
2. Agglutination assay
3. Immunochromatographic assay (lateral flow)
4. Dipstick and comb assay
• NACO recommends use of rapid test kits, which detect >99.5%
of all HIV-infected individuals
• False-positive results in <2% of all those who are tested.

40. ELISA
• HIV antigens or antibodies attached to a solid phase (matrix)
• Incorporated with a conjugate and substrate detection system.
• Viral antigens may be whole viral lysates, recombinant, or
synthetic peptides.
• Matrix can be “wells” or “strips” of a microplate, plastic beads,
or nitrocellulose paper.
• Conjugates are antibodies (lgG, lgM and IgA) coupled to
enzymes (alkaline phosphatase or horseradish peroxidase )

41. • Substrates used are:
1. 4-nitrophenylphosphate – for alkaline phosphatase
2. o-phenylenediamine dihydrochloride (OPD)
3. TMB – for horseradish peroxidase
which produce colour on being acted upon by the respective
enzymes.
• In case the enzyme conjugates, the signal generated is a
colour reaction
• The colour can be measured on an ELISA Reader as optical
density (OD) values

44. On the basis of the principle of the test, ELISA can be divided
into:
• Indirect
• Competitive
• Sandwich
• Capture

45. Indirect ELISA
Most commonly used principle.
HIV antigens are attached covalently to the solid phase
This allows HIV antibodies present in the specimen to bind.
Bound antibodies are detected by enzyme labelled anti- human
immunoglobulin and a specific substrate system.
If the test specimen contains anti-HIV antibodies, a colour reaction will
take place.

48. Rapid Tests
Immunochromatographic
assay

50. Western Blot Test
• HIV specific recombinant or synthetic
antigens are absorbed on nitrocellulose
paper.
• Antibody, when present, attaches to the
antigen on the strip and the antigen
antibody complex is then detected using
enzyme conjugate and substrate.
• WB detect presence of antibodies against
specific HIV proteins, which are seen as
bands on the strip

51. Window Period
• HIV antibodies become detectable by IgM ELISA typically 3
weeks after infection.
• Period from the time the virus enters the host until detectable
levels of HIV specific antibodies appear is called the ‘window
period’ or ‘acute infection phase.’
• During this period, an individual is infected and is also infectious
to other individuals .
• Antibody levels are not detectable during this phase of the
infection, rendering the person sero-negative.

52. Detection of Acute HIV Infection
• Antibody tests detect both HIV-1 and HIV-2 antibody
approximately 22 days after the viremic phase of HIV infection
begins.
• Antigen testing for p24, after approximately 16 days.
• The nucleic acid amplification test (NAT), which detects HIV-1
RNA reduces the window period to 11 days.
• NAT result may turn out negative if tested within 7 to 10 days of
exposure.

53. Detection of virus and viral products
NAT:
• The process of screening donor samples for viral nucleic acid
(RNA) or (DNA)
• NAT requires the extraction of nucleic acid from donor
plasma followed by use of a nucleic acid amplification test to
amplify and detect viral genetic sequences
• At present, NACO does not recommend the use of NAT for the
diagnosis of acute HIV infection.
• NATs include tests for qualitative detection of HIV-1 DNA or
RNA, quantitative detection of HIV-1 RNA (viral load
determination) through various assays.

57. Strategy I (blood transfusion/transplant
safety)
• Specimen subjected to one test for HIV reactivity.
• The test used in strategy I must have high sensitivity.
• If non reactive, the specimen is considered as HIV negative.
• If reactive the specimen is considered as HIV positive.
• Used for ensuring donation safety (e.g., blood, blood products,
organs, tissues, sperms etc.)
• Unit of blood that tests reactive is discarded.
• Donor is to be notified of his result, based on his prior consent
and referred to an ICTC for the confirmation of the diagnosis.

63. The risk of transfusion-transmitted HIV can be reduced through a
variety of measures:
1. Donor education and questioning
2. Shortening of the window period : by improving and/or adding
tests to detect earlier stages of infection.
3. Exclude donors at increased risk of blood-borne or sexually
transmitted infections.
4. Surveillance for transfusion-transmissible diseases

64. Refrences
HIV SENTINEL SURVEILLANCE 2017 (NACO)
National Guidelines for HIV Testing 2016 (NACO)
Rossi’s Principles of Transfusion Medicine.5th Edition
AABB Technical manual. 18th Edition
Robbins Basic Pathology. 9th Edition

65. THANK YOU