Lesson 4: Laboratory diagnosis of viral diseases Flashcards
used in studying the expression of specific viral genomes on the different cell types
DNA probes
Used specifically to detect latent and integrated sequences of viruses, and viruses present in low concentration in clinical specimens
Polymerase Chain reaction (PCR)
Reverse transcriptase (RT PCR)
detect specific viral antibodies in serum of the infected host; it is used to identify the virus and its strain or serotype; it is used to determine whether viral infection is an acute or chronic infection or primary infection or reinfection; it is used for diagnosis of viral infections that cause diseases of long duration; it is used for diagnosis of infection caused by viruses that are difficult to culture
viral serology
used for detection of viruses that agglutinate red blood cells of chickens, guinea pigs, human or other mammals
hemagglutination inhibition (IH) test
used based on inhibition of infection by the antibody and that of CPEs of the viruses in tissue culture cells
neutralization test (NT)
direct examination from respiratory system
nasopharyngeal aspirate
serology from respiratory system
throat swab, throat washing
direct examination from central nervous system
brain biopsy or cerebrospinal fluid
serology from central nervous system
feces, blood (for arbovirus), cerebrospinal fluid and brain biopsy
direct examination from skin
vesicular or pustular fluid, ulcer scrapings and crusts
serology from skin
macular or papular scrapings, vesicular/pustular fluid, ulcer scrapings, crust, urine
direct examination from eye
conjunctival scrapings and smears
serology from eye
conjunctival scrapings or swabs
direct examination from liver
serum and feces
serology from liver
blood ( yellow fever)
