Sexually Transmissible Viral Pathogens: Human Papillomaviruses and Herpes Simplex Viruses
Attila Lorincz in Nucleic Acid Testing for Human Disease, 2016
Antigen detection tests are also generally less sensitive than HSV ascertainment via conventional culture.126 Tzanck smear preparation is a morphologic assay used in the past that cannot differentiate HSV and varicella zoster virus (VZV) infections and is less sensitive than viral culture. The direct fluorescent antibody test provides quick results but its optimum use generally requires the presence of clinical lesions.127 Cytological diagnosis, electron microscopy, and early hybridization assays have also been used to directly detect HSV genital infection, although these tests have also been hampered by relatively low sensitivities.122,128 An hc2 signal amplification probe test for the rapid detection and typing of herpes simplex virus DNA has also been described, with results indicating high sensitivity (93%) and specificity (100%).129
Human Metapneumovirus Infections
Sunit K. Singh in Human Respiratory Viral Infections, 2014
Reverse transcription PCR (RT-PCR) is a commonly used tool for diagnosis in the clinical setting and is considered the gold standard. Assays have been validated using the F, N, and other proteins,127 and the N and L proteins have demonstrated high sensitivity.128,129 Recently, new PCR primers developed from multiple divergent GenBank sequences were described to have high sensitivity and specificity.130 Multiplex RT-PCR assays have been developed to test for multiple respiratory pathogens at one time, with good sensitivity and specificity. As many as 18 respiratory viruses can be assessed in one test.131 Point-of-care antigen testing is not as sensitive as RT-PCR and is not commercially available.132 Immunofluorescent antibody testing is rapid but has a sensitivity of 73% compared to PCR.133 Direct fluorescent antibody staining has similar sensitivities and specificities.134 Shell vial culture assays have also been used.135 An analysis of cell culture using Vero cells demonstrated 80% sensitivity compared to RT-PCR.136
Chlamydia trachomatis
Peter M. Lydyard, Michael F. Cole, John Holton, William L. Irving, Nino Porakishvili, Pradhib Venkatesan, Katherine N. Ward in Case Studies in Infectious Disease, 2010
Antibody-based laboratory techniques include direct fluorescent antibody (DFA) detection and enzyme-linked immunosorbent assay (ELISA). The latter can be used for determination of the serovars. Usually diagnostic antibodies target group-specific LPS or serovar-specific outer-membrane proteins (OMPs). These methods are not as good as cell culture, particularly when samples contain few bacteria in asymptomatic patients. However, ELISA-based technology is widely used in screening programs and is of great help in reducing the overall chlamydial infection and incidence of PID and nongonococcal urethritis.
A case of rheumatoid arthritis complicated with mucous membrane pemphigoid
Published in Modern Rheumatology Case Reports, 2021
Ryosuke Hanaoka, Toshiko Haginoya, Masami Koike
Biopsy of the oral mucosa revealed epidermal exfoliation, perhaps because the biopsy sample was taken from the base of the ulcer (Figure 3(A)). Lymphatic vessels located directly below the epidermis were enlarged and contained numerous neutrophils and few eosinophils centred around the capillaries, accompanied by severe infiltration of lymphoid and other small round cells (Figure 3(B,C)). Severe fibrosis of the dermis was also observed. The direct fluorescent antibody method was applied to a sample of the patient’s lip tissue. Complement component 3 (Figure 3(D)) and IgG (Figure 3(E)) deposits were seen in the epidermal basement membrane. The indirect fluorescent antibody method was also applied to a sample of the patient’s lip tissue. Normal mucosa was treated in 1 M saline for 48 h, and the dermis and epidermis were removed before adding serum from the patient, resulting in the appearance of linear deposits on the epidermis side (Figure 3(F)). Based on these findings, MMP was diagnosed.
An audit of inpatient stool ova and parasite (O&P) testing in a multi-hospital health system
Published in Journal of Community Hospital Internal Medicine Perspectives, 2020
Mohammad Qasim Khan, Nicole Gentile, Ying Zhou, Becky A. Smith, Richard B. Thomson, Eugene F. Yen
The labor-intensive nature of the traditional O&P exam, requiring a skilled technician, has led to the development of alternative methods of detecting fecal parasites. Direct fluorescent antibody tests, enzyme immunoassays, and immunochromatographic lateral flow assays, while more sensitive and specific than O&P exams, are available for only a limited number of organisms and are generally more expensive than direct microscopic examination [24]. As testing methods advance, laboratories will need to re-evaluate the availability of equipment, skill level of technicians, testing volume, test performance characteristics, specimen collection requirements and kit costs when deciding on the most ideal method to detect ova and parasites [24].
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