Lakhasly

VIRUS IDENTIFICATION There are three major methods to diagnose viral infections: direct detection in the clinical specimen, specific antibody assay to detect viral antibodies in the serum, and viral culture. Direct detection methods include: (1) electron microscopy, which is used primarily by reference laboratories; (2) enzyme- linked immunosorbent assay (ELISA) for viruses such as respiratory syncytial virus (RSV), Hepatitis B surface antibody, and rotavirus; (3) latex agglutination for viruses such as rotavirus and RSV; (4) DNA probes for viruses such as cytomegalovirus (CMV); (5) polymerase chain reaction (PCR) for DNA detection for viruses such as HIV types 1 and 2; (6) optical immunoassay (OIIA), an antibody antigen- based test that produces a reflection change for detection of influenza viruses A and B from respiratory specimens; (7) light microscopy of cell scrapings from infected sites can detect Cowdry type A inclusion bodies from herpes simplex virus and varicella zoster virus; (8) Papanicolaou (Pap) smears for the effect of human papillomavirus on squamous cells; and (9) Negri bodies for the diagnosis of rabies. Viral infections cause an immunogenic response; therefore, antibody detection methods can be useful in the diagnosis of infection. Simple antibody tests can determine the presence or absence of immunoglobulin (Ig). This can be used to determine if a patient has ever been infected with a specific virus (e.g., varicella, adenovirus). Complex antibody detection systems use a battery of viral antigens and often distinguish IgM (early) from IgG (late) antibodies. Specific antibody detection has some inherent issues that can limit effective use of this methodology, including: • Measurement of the patient's response to the virus and not actual detection of the virus • Antibody production varies based on the patient's immune system Antibody level doec not necessarily correlate wMith acuteness or activity. Jevel of the disease state

VIRUS IDENTIFICATION There are three major methods to diagnose viral infections: direct detection in the clinical specimen, specific antibody assay to detect viral antibodies in the serum, and viral culture. Direct detection methods include: (1) electron microscopy, which is used primarily by reference laboratories; (2) enzyme- linked immunosorbent assay (ELISA) for viruses such as respiratory syncytial virus (RSV), Hepatitis B surface antibody, and rotavirus; (3) latex agglutination for viruses such as rotavirus and RSV; (4) DNA probes for viruses such as cytomegalovirus (CMV); (5) polymerase chain reaction (PCR) for DNA detection for viruses such as HIV types 1 and 2; (6) optical immunoassay (OIIA), an antibody antigen- based test that produces a reflection change for detection of influenza viruses A and B from respiratory specimens; (7) light microscopy of cell scrapings from infected sites can detect Cowdry type A inclusion bodies from herpes simplex virus and varicella zoster virus; (8) Papanicolaou (Pap) smears for the effect of human papillomavirus on squamous cells; and (9) Negri bodies for the diagnosis of rabies. Viral infections cause an immunogenic response; therefore, antibody detection methods can be useful in the diagnosis of infection. Simple antibody tests can determine the presence or absence of immunoglobulin (Ig). This can be used to determine if a patient has ever been infected with a specific virus (e.g., varicella, adenovirus). Complex antibody detection systems use a battery of viral antigens and often distinguish IgM (early) from IgG (late) antibodies. Specific antibody detection has some inherent issues that can limit effective use of this methodology, including: • Measurement of the patient's response to the virus and not actual detection of the virus • Antibody production varies based on the patient's immune system Antibody level doec not necessarily correlate wMith acuteness or activity. Jevel of the disease state