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Transfusion-Transmitted Infections. Introduction Blood transfusion is the process of receiving blood or blood products into circulation intravenously.

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Presentation on theme: "Transfusion-Transmitted Infections. Introduction Blood transfusion is the process of receiving blood or blood products into circulation intravenously."— Presentation transcript:

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 Consent Form Medical examination Donor Screening Blood Donation: o Blood donation procedure Post donation  Rest, advice & refreshment  Donor certificate, Donor ID card

5 Criteria for Blood Donation (WHO Recommendations) Age: 18-55 years old. Weight: 50 Kg or above. Pulse rate: normal 60–100/minute; regular rhythm. Body temperature: normal 36- 37.6°C. 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, psychosis, bleeding tendencies, thalassemia, sickle cell anemia, cancer. Infections: HIV, hepatitis, malaria, syphilis.

6 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. Blood is usually stored in a flexible plastic bag that also contains sodium citrate, phosphate, dextrose, and sometimes adenine.

7 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.

8 Infectious Microbes Transmitted by Blood Transfusion

9 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.

10 Human Immunodeficiency Virus (HIV): Classification Family: retroviridae. Genus: lentivirus. Specie (types): HIV-1, HIV-2. Lentiviruses are single-stranded (SS), enveloped icosahedral RNA viruses.

11 Integrase

12 HIV Replication Cycle  attachment (interaction b\w gp120 and CD4) then attachment to the co-receptors: CCR5 & CXCR4.  Entry and uncoating  Formation of Ds DNA by reverse transcriptase enzyme, and integration by integrase enzyme.  Stay latent or reproduce (produce RNA and proteins).  Assembly.  release by budding destroying the cell.


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

15 Human T cell Lymphotropic Viruses (HTLV) type I and type II Virology: Ss RNA, enveloped, icosahedral Family: retroviridae. Genus: deltaretrovirus Oncovirus. 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.

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

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

18 incomplete filamentous forms

19 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. Diagnosis: Detection of hepatitis B virus surface antigen (HBs Ag) and anti-HBc by ELISA. PCR

20 CDC: HBV prevalence 2012

21 Hepatitis C virus  Virology: enveloped, Ss RNA virus.  Family: flaviviridae, Genus: hepacivirus.  Transmission: o Blood\ blood products transfusion. o Injection drug use. o Needle sticks or sharps exposure: range 0%-7%). o Sexual exposure.  In developing countries, the primary source of HCV infection are inadequately screened blood and blood products and unsterilized injection equipment.

22 Diagnosis: PCR, ELISA (anti- HCV). Hepatitis C transmission in developed countries

23 Epstein - Barr virus: (EBV) Virology Family: Herpesviridae. Enveloped, icosahedral, Ds DNA. Derives envelope from the nuclear membrane of the host cells. Establishes latency in B lymphocytes. Transmission Direct person-person contact (saliva). Most adults are seropositive. Blood transfusion.

24 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).

25 Downey cells Normal lymphocyte

26 EBV Diseases and malignancies Diseases: asymptomatic in infants and young children. Infectious mononucleosis (heterophile positive 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. Malignancies: Burkitt lymphoma Nasopharyngeal carcinoma Hodgkin lymphoma.

27 Hairy leukoplakia

28 Burkitt lymphoma of the jaw Diagnosis (serology): Anti-E.B virus IgM antibodies detected by ELISA test

29 END of Lecture 1

30 Cytomegalovirus (CMV) Family: Herpesviridae like EBV. Transmission: Saliva, sexual, blood transfusion, vertical (during pregnancy, breast milk). Pathogenesis: CMV infects the salivary gland epithelial cells and fibroblasts. Latency in monocytes and macrophages (mononuclear cells). Approximately 50% to 80% of the adult population are infected with the virus.

31 Infectious mononucleosis syndrome (heterophile negative): same symptoms but usually asymptomatic or mild. Congenital infection: Cytomegalic inclusion body disease: jaundice, hepatosplenomegaly, pneumonitis, CNS damage (loss of hearing & mental retardation), death. In immunocompromised patients : AIDS, tissue transplant: interstitial pneumonitis to severe systemic infection.


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. Diseases: In children and adults; Fifth disease; erythema infectiosum; slapped cheek disease. In fetuses: Hydrops fetalis (sever anaemia & edema).


36 Human Herpes Virus 8 (HHV-8) Virology: enveloped Ds DNA, 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. Disease: Kaposi Sarcoma in immunosuppressed esp. AIDS patients. Diagnosis: serology: ELISA or molecular genetics: PCR.

37 Kaposi sarcoma

38 Bacterial contamination The most common and severe infectious complication associated with transfusion (past). It has been estimated that 1 in 40,000 units of blood and 1 in 3,300 units of platelets are contaminated with bacteria. Normal flora of the skin, such as S.epidermidis or S.aureus (gram positive cocci), are the most common bacterial contaminants of blood products. Gram negatives such as E.coli, may contaminate the donation when blood is collected from donors who have bacterial infection without symptoms.

39 Treponema pallidum Bacteriology: Thin spirochete; basically it has Gram’s negative cell wall. Axial filaments present (endoflagella). Can not be cultivated in vitro; serodiagnosis. Obligate pathogen (but not intracellular). Transmission: sexually, transplacentanlly and by blood transfusion (rare; 6 in million; can not survive more than 48 hrs. in refrigerator).

40 Chancre

41 Pathogenesis: Primary: genital chancre of skin Secondary: skin lesions Latent infection Tertiary: CNS and cardiovascular infection. Diagnosis Direct: Detection of the bacteria 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.

42 Dark field microscopyImmunofluorescent microscopy

43 Malaria About 300-500 million people are infected, over 1 million people die each year. Microbiology: Classification: Sporozoa. Plasmodium species (P. vivax, P. malariae, P. ovale, P. falciparum) Transmission: bite of female Anopheles mosquito, transplacental and by blood transfusion. Man is the intermediate host (asexual stage of microbe = Schizogony cycle). Anopheles is the definitive host (sexual stage = Sporogony cycle).



46 sexual cycle (Sporogony) Asexual cycle (Schizogony)

47 Pathogenesis: Infection of liver: jaundice, hepatomegaly. Infection of red blood cells: infectious hemolytic anemia, splenomegaly.


49 Diagnosis: Rapid dip stick tests. Thick and thin blood smears. Plasmodium falciparum gametocytes

50 Map showing the distribution of malaria in the world: ♦ Elevated occurrence of chloroquine- or multi-resistant malaria. ♦ Occurrence of chloroquine-resistant malaria. ♦ No Plasmodium falciparum or chloroquine-resistance. ♦ No malaria.


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