1. Source of infection D-r Mitova MU-Sofia

35. Gastro Intestinal / Fecal Oral Route Transmission by the fecal-oral route is the second most important mode of transmission after the respiratory tract 􀁺 excreted by the feces 􀁺 transmitted to the oral portal of entry through 􀂃 contaminated food 􀂃 contaminated water, milk, drinks 􀂃 hands 􀂃 flies Viruses with envelopes do not survive exposure to hydrochloric acid in the stomach, bile acids in the duodenum, salts and enzymes of the gut. Small enterovirus without envelope (Norwalk agent, rotavirus, polio and coxsackie are able to resist. HepatitisA and E are also transmitted by the fecal oral route.

36. Transmission by gastrointestinal route Fecal oral route 􀁺 Typhoid fever 􀁺 Shigella 􀁺 Cholera 􀁺 Polio 􀁺 Coxsackie, Echo, Reo 􀁺 Norwalk agent 􀁺 Rotavirus 􀁺 Hepatitis A, Hepatitis E

54. Laboratory diagnosis of shigellosis and salmonellas salmonella

57. LABORATORY DIAGNOSIS OF CHOLERA

58. LABORATORY DIAGNOSIS

60. Isolation requires special media (chocolate agar or Bordet-Gengou medium). The organism requires both the X and V factors for growth especially for initial isolation. B.pertussis Bordet-Gengou medium

64. N. meningitidis.

70. Source of virus feces blood/ blood-derived body fluids blood/ blood-derived body fluids blood/ blood-derived body fluids feces Route of transmission fecal-oral percutaneous permucosal percutaneous permucosal percutaneous permucosal fecal-oral Chronic infection no yes yes yes no Prevention pre/post- exposure immunization pre/post- exposure immunization blood donor screening; risk behavior modification pre/post- exposure immunization; risk behavior modification ensure safe drinking water Type of Hepatitis A B C D E

74. High Moderate Low/Not Detectable blood semen urine serum vaginal fluid feces wound exudates saliva sweat tears breastmilk Concentration of Hepatitis B Virus in Various Body Fluids

83. Diagnostic Methods in Virology 1. Direct Examination 2. Indirect Examination (Virus Isolation) 3. Serology

84. Direct Examination 1. Antigen Detection immunofluorescence, ELISA etc. 2. Electron Microscopy morphology of virus particles immune electron microscopy 3. Light Microscopy histological appearance inclusion bodies 4. Viral Genome Detection hybridization with specific nucleic acid probes polymerase chain reaction (PCR)

85. Indirect Examination 1. Cell Culture cytopathic effect (CPE) haemabsorption immunofluorescence 2. Eggs pocks on CAM haemagglutination inclusion bodies 3. Animals disease or death

86. Serology Detection of rising titres of antibody between acute and convalescent stages of infection, or the detection of IgM in primary infection.

87. ELISA for HIV antibody Microplate ELISA for HIV antibody: coloured wells indicate reactivity

91. Schematic of PCR Each cycle doubles the copy number of the target

92. Some Pathogens that Cross the Placenta