Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Transfusion Medicine and Blood Bank 13 Transfusion Transmitted Diseases PPT-Powerpoint Presentations and lecture notes
TRANSFUSION TRANSMITTED INFECTIONS
CONTENTS
? TTI ?
? Characteristics of TTI
? Mandatory TTI
? Methods/Technologies for TTI Testing
? TTI Notification
? Why & How To Notify
TRANSFUSION CHAIN
Human
being
Blood donors
(Donor)
Each link consists of
several
Collection
smaller links
(primary processes)
Processing
Screening
and testing
The quality of the BTS is
Blood cold
influenced by the quality
chain
of each of the links
Transfusion
Human
being
(Patient)
TTI = TRANSFUSION TRANSMISSIBLE INFECTIONS
A pathogen :
? Able to transmit through blood or blood components
? Able to survive outside human body
? Able to survive through range of temperatures
? Able to replicate and re-establish following transfusion
? Exists naturally either free in plasma or in cellular component
INFECTIOUS AGENTS
1. Virus ? most commonly transmitted
2. Bacteria
3. Protozoa
4. Fungi ? not accepted as blood donor(too sick)
5. Parasite
6. Prion
VIRUS
1. Hepatitis: Hep B, Hep C, Hep D
2. Human immunodeficiency virus (HIV)
3. Human T-cell Lymphotrophic virus (HTLV-1,2)
4. Epstein barr virus (EBV)
5. Cytomegalo virus (CMV)
6. West nile virus (WNV)
7. Human herpes virus (HHV)
BACTERIA
1. Treponema pallidum
2. Yersinia enterocolitica
3. Pseudomonas
4. Propionibacterium acnes
5. Staphylococcus epidermidis
6. Bacillus cereus
PARASITES
1. Plasmodium species
2. Babesia microti
3. Trypanosoma Cruzi
4. Leishmania species
5. Toxoplasma gondi
PRIONS
Creutzfeld Jacob disease / Variant Creutzfeld Jacob disease
CHARACTERISTICS OF TTI
? Asymptomatic or only mild symptoms in donors ?hence pass
donor screening criteria
? Long incubation period before clinical signs and symptoms
appear
? Stability in blood at 4OC or lower
? Might cause a carrier state of infection (HBV, HCV)
HOW AND WHAT TO TEST ?
? Identify structural protein
? Identify antibody produced
? Identify antigen
? Identify nuclear material
HOW TO TEST?
? Rapid tests
? ELISA
? Chemiluminescence assay(CLIA)
? Nucleic Acid Amplification Testing (NAT)
SELECTION OF SCREENING ASSAYS
? What is the test?
? Who is going to use it?
? Is the staff experienced or newly recruited?
? What are the constraints?
? Are resources available?
? Are results needed in a very restricted period of
time?
? How is it to be used? Large or small number of
specimens?
? What are the existing systems?
MANDATORY TTI TESTING
Under Drugs and Cosmetic Act 1940
Rules 1945 amendments thereafter, (SCH. F, Part XI B)
Ministry of Health And Family Welfare
Government of India
Screening of each blood & blood components is Mandatory
? HBsAg
? Anti HIV 1 & 2
? Anti HCV
? VDRL
? Malarial parasite
MANDATORY TTI TESTING
HIV 1 & 2, Hepatitis C,, Hepatitis B Syphilis & Malaria
1. Screening for antibodies to HIV-1 & 2
( Rapid/3rd or 4th generation ELISA /Chemiluminescence and / NAT )
2. Screening for antibodies to HCV
( Rapid/3rd or 4th generation ELISA /Chemiluminescence and / NAT )
3 Hepatitis B Surface Antigen
( Rapid/ 3rd or 4th generation ELISA /Chemiluminescence and / NAT )
4. Syphilis ( TPHA/VDRL/RPR )
5. Malarial parasite (PBF / Rapid card test )
MANDATORY BLOOD SCREENING FOR INFECTIOUS MARKERS
Infectious
Year of
Mandatory Testing
Newer Technologies
Markers
Enforcement Technology
Syphilis
1975
RPR/VDRL/TPHA
ELISA
Hepatitis B
1975
ELISA/Rapid
Chemiluminescence/NAT
virus
Malaria
1975
Smear/Rapid
ELISA
HIV
1988
ELISA/Rapid
Chemiluminescence/NAT
Hepatitis C
2001
ELISA/Rapid
Chemiluminescence/NAT
Virus
RECENT CONCERNS
? Latency and carrier state leading to persistent infections: HIV,
HBV, HCV were major concerns but Hep A and Hep E
? Emerging infections like Dengue Virus ,West Nile Virus, Zika Virus,
and others are posing risk for infection
VARIOUS TESTING TECHNOLOGIES
Technology
Window Period
HIV
HCV
HBV
ELISA-I I Generation
20.6 days
58.3 days
36.3 days
ELISA-IV
13.7 days
9.4 days
24 days
Generation
ID NAT
5.6 days
4.9 days
20.6 days
IDEAL ELISA PLATE(96 wells) LAYOUT
RAPID TESTS
Employ a variety of techniques
? Dot blot assays
? Particle agglutination
? Spot tests
? Immuno- chromatographic tests or Card Tests
? Most have sensitivities and specificities of 99% and 98%
respectively
Applications of Rapid tests
? Useful in small blood banks
? Useful in emergency
RAPID IMMUNOCHROMATOGRAPHIC ASSAY
POSITIVE
NEGATIVE
INVALID
MALARIA CARD TEST
NEGATIVE
POSITIVE
INVALID
CHEMILUMINESCENCE IMMUNOASSAY
? Principle: It is the production of light [Luminescence] from an
oxidation-reduction chemical reaction.
? Two chemicals react to form an excited (high-energy) intermediate,
which breaks down releasing its energy as photons of light and
interpreted as Optical density value.
NAT
NAT TESTING
DONOR NOTIFICATION
Why should the donors be informed of test results?
? Results are significant to their health
NBTC/NACO
? Ensures no further donations
Recommendation
? Unethical to hold information
? Informing about Pathology - acute and chronic
? Secondary transmission - sexual, mother to child, close physical contact
? Mode of infection-why not excluded by donor selection
? Treatment and management
? General surveillance and epidemiology
? acute infection (WP)
? To improve testing methodology
HOW TO NOTIFY ?
? Follow NACO/NBTC policy on how to notify donors about positive TTI
? Tell the results on a face-to-face basis
? Counsellor - well-trained in counselling skills
? Given in person, never on telephone
? Maintain confidentiality
? Opportunity to ask questions / discussion
? Further appointment offered
REFERRAL
? Refer the donor to other sources of advice and support
HIV - ICTC (Integrated Counselling and Testing Center)
HBV/HCV - Medicine / Gastro/ Hepatologist
Syphilis - Dermatology / STD Clinic
Malaria - Physician /Medicine
IMPACT ON BLOOD DONORS
? What will the test result mean?
? Will I become ill?
? What about my partner / offspring?
? Am I infectious?
? How did I become infected?
? Is infection treatable?
This post was last modified on 08 April 2022