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Transfusion-Transmitted Infections

Transfusion-Transmitted Infections. Introduction. Blood transfusion is the process of receiving blood or blood products into circulation intravenously. Used in a variety of medical conditions to replace lost components of the blood such as:

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Transfusion-Transmitted Infections

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  1. Transfusion-Transmitted Infections

  2. Introduction • Blood transfusion is the process of receiving blood or blood products into circulation intravenously

  3. Used in a variety of medical conditions to replace lost components of the blood such as: • Inherited blood diseases: Thalassemia, hemophilia, sickle cell anemia • Hemolytic anemia of newborn. • Bleeding: Post –traumatic, operative • Malignancy: leukemia • Other conditions: hepatic coma, kidney failure

  4. Procedure for Voluntary Blood Donation Pre-Donation: • Donor Screening • Donor Consent Form • Medical examination Blood Donation: • Blood donation procedure Post donation • Rest, advice & refreshment • Donor Certificate, Donor ID card

  5. Criteria for Blood Donation(WHO Recommendations) Donors are evaluated for safety according to the following criteria: • Age: 18-55 years old • Weight: 50 Kg or above • Pulse Rate: Normal 60–100 per minute and a regular rhythm • Body temperature: Normal 36- 37.6°C

  6. Blood pressure: Normal(systolic 120–129 mmHg, diastolic 80–89 mmHg) • Hemoglobin concentration: 12.5 g/dl for females and 13.5 g/dl for males • Medical History, epilepsy, psychotic disorders, bleeding tendencies, thalassemia, sickle cell anemia, malignancy • Infections: HIV, hepatitis, malaria, syphilis

  7. How much blood can be taken during blood donation? • The amount of blood drawn varies from 200 milliliters to 550 milliliters depending on the country, but 450-500 milliliters is typical • The blood is usually stored in a flexible plastic bag that also contains sodium citrate, phosphate, dextrose, and sometimes adenine

  8. Factors that play a role in establishment of blood transfusion infection • Viral Window Period: period between the onset of infection and the appearance of detectable antibodies to the virus(3-6 weeks up to 6 months) • Donor immune status (Asymptomatic immunocompetent donor) • Laboratory and personal error • Bacterial contamination

  9. The Infectious Microbes Transmitted by Blood Transfusion

  10. Transfusion Transmitted Infections (TTI) • HIV • HTLV • Hepatitis B and C • Cytomegalovirus • Epstein-Barr virus • Human Parvovirus (B19) • Human Herpesvirus 8 • Bacterial contamination of blood products • Syphilis • Malaria • prions

  11. Human Immunodeficiency Virus (HIV): • Classification • Family: retroviridae • Genus: lentivirus • Specie (types): HIV-1, HIV-2 • Lentivirusesare single-stranded, positive-sense, enveloped icosahedral RNA viruses.

  12. Integrase

  13. HIV Replication Cycle • attachment (interaction b\w gp120 and CD4) then interact with CCR5 and CXCR4 • Entry and Uncoating • Formation of Ds DNA by reverse transcriptase enzyme, and integration by integrase. • Stay latent or reproduce (produce RNA and proteins) • Assembly • release by budding destroying the cell

  14. Routs of HIV Transmission • Unprotected sexual transmission • Blood transfusion • From mother to child (late in pregnancy, during birth and breast feeding) • Needle-sharing injection drug use • Percutaneous needle stick • Tissue transplantation

  15. Human T cell Lymphotropic Viruses (HTLV) type I and type II Virology: • Single stranded ss RNA • enveloped • Icosahedral • Family: retroviridae • Genus: deltaretrovirus • Oncovirus

  16. Pathogenesis • The virus infect T cells and, activate some host cell genes; and places the infected cell in an uncontrolled mode of growth • The majority of infected patients stay as carriers. • Some patients develop Adult T-cell leukemia (ATL) after 20-30 years.

  17. EpidemiologyIt is endemic in Japan (15-30%), Caribbean (3-6%), Guinea and some parts of Africa • Transmission: • Sexual route • Blood transfusion • Vertical transmission and breast-feeding • Laboratory diagnosis: • PCR for detection of provirus genome • Anti-HTLV antibodies by ELISA

  18. Hepatitis B Virus • Family: Hepadnaviridae • Icosahedral enveloped Ds DNA virus • One of the smallest enveloped animal viruses. • Pleomorphic forms exist, including spherical and filamentous bodies lacking a core (none infectious lipids and proteins surface antigen (HBs Ag))

  19. incomplete forms

  20. Transmission • Highly infectious • Sexual Route • Vertical Route: Transmission of virus from mother to child during childbirth perinatal, transmission of viral genetic material within the cells. • Parenteral Route: Blood transfusion and contaminated syringes

  21. Diagnosis • Hepatitis B virus surface antigen (HBs Ag) detection by ELISA for diagnosis • Differentiation between acute and chronic infection

  22. Hepatitis C virus • Virology: enveloped, Ss RNA virus • Classification • Family: flaviviridae, Genus: hepacivirus • Transmission • Blood\blood products transfusion • Injection drug use • Needle sticks or sharps exposure:1.8% (range 0%-7%) • Sexual exposure

  23. In developing countries, the primary sources of HCV infection are inadequately screened blood and blood products Hepatitis C transmission in developedcountries

  24. Epstein - Barr virus: (EBV) • Virology • Family: Herpesviridae • Enveloped, Icosahedral, Ds DNA • Derives envelope from nuclear membrane • Establishes Latency in B lymphocytes. • Transmission • Direct person-person contact (Saliva) • Blood transfusion. • Most adults are seropositive.

  25. Pathogenesis • EBV infects nasopharyngeal epithelial cells, salivary and lymphoid tissues • The virus binds to CD21 of B-Lymphocytes and acts as mitogen (encourages a cell to commence cell division) • This will stimulate the production of atypical reactive T cell (Downey cells=70% of the total WBC count)

  26. Downey cells

  27. EBV Diseases and malignancies • Diseases: asymptomatic in infants and young children • Heterophilepositive mononucleosis (infectious mononucleosis) (kissing disease)Fatigue, fever, sore throat, lymphadenopathy, and splenomegaly • Lymphoproliferative disease: Uncontrolled B-Cell growth in immunocompromised patients • hairy leukoplakia: nonmalignant, white-gray lesions on the tongue in AIDS patients.

  28. Hairy leukoplakia

  29. Malignancies • Burkitt lymphoma • Nasopharyngeal carcinoma • Hodgkin lymphoma • Diagnosis (serology) • Anti-E.B virus IgM antibodies detected by ELISA test

  30. Lymphadenopathy

  31. Cytomegalovirus (CMV) • Virology • Belongs to the Herpesviridae family like EBV • Transmission: Saliva, sexual, blood transfusion, vertical (during pregnancy, breast milk) • Pathogenesis • Latency in monocytes and macrophages (mononuclear cells). • Approximately 50% to 80% of the adult population are infected with the virus

  32. Mononucleosis syndrome (like IM): usually asymptomatic or mild symptoms. • cytomegalic inclusion body disease , jaundice, hepatosplenomegaly, pneumonitis, CNS damage (loss of hearing & mental retardation), death. (most sever in vertical transmission) • Interstitial pneumonitis to severe systemic infection (immunocompromised patients : AIDS, tissue transplant)

  33. Parvovirus B19 • Virology • Ss DNA virus, non enveloped, icosahedral virus • Transmission • Respiratory, vertical (from mother to child), blood transfusion • This virus has been transmitted to patients with hemophilia through infusion of clotting factors

  34. Pathogenesis • It infects immature erythroid progenitor cells, resulting in cell lysis • The resulting anemia is clinically significant in patients with sickle cell anemia • Disease • In children and adults • Fifth disease; erythema infectiosum (slapped cheek disease) • In fetus • Severe anemia, hydrops fetalis (anaemia & edema)

  35. Human Herpes Virus 8 (HHV-8) • Virology: enveloped Ds DNA virus, family: herpesviridae • Transmission: Sexual contact, Saliva, vertical, transplantation & transfusion • Pathogenesis • It has a gene that turns on vascular endothelial growth factor (VEGF), which plays a direct role in the development of Kaposi Sarcoma

  36. Disease: Kaposi Sarcoma in immunosuppressed esp. AIDS patients. • Diagnosis • Serology: ELISA • Molecular genetics: PCR

  37. Bacterial contamination • The most common and severe infectious complication associated with transfusion • It has been estimated that 1 in 38,500 units of red cells, 1 in 3,300 units of random donor platelets, are contaminated with bacteria

  38. Gram–positive bacteria normally found on the skin, such as S.epidermidisor S.aureus, are the most common bacterial contaminants of blood products. • Gram negative bacteria, such as E.coli, may contaminate the donation when blood is collected from donors who have bacterial infection without symptoms.

  39. Improved methods of collection, handling, and storing of blood products has decreased bacterial contamination in recent years.

  40. Treponema pallidum • Transmission: Sexually, transplacentanllyand by blood transfusion (rare; 6 in million; can not survive more than 48 hrs. in refrigerator) • Bacteriology • Thin spirochete; Basically it has Gram’s negative cell wall • Axial filaments present (endoflagella) • Can not be cultivated in vitro; serodiagnosis

  41. Obligate pathogen (but not intracellular) • PathogenesisPrimary: genital chancre of skinSecondary: skin lesionsLatent infectionTertiary: CNS and cardiovascular infection

  42. Chancre

  43. Diagnosis • Direct: Examination of microbe by Dark field or immunofluorescent microscopes. • Indirect (Serology) • Non treponemal antibodies (non-specific antibodies): Anti-cardiolipin by VDRL or RPR test • Treponemal antibodies (specific): by TPHA or IFA

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