Cytomegalovirus
Avindra Nath, Joseph R. Berger in Clinical Neurovirology, 2020
Serology can detect antibody formation and may indicate current or past infection. However, serologic tests can be difficult to interpret, especially in some immunocompromised hosts. Classically, CMV-specific IgM suggests recent infection and IgG suggests past infection. Demonstration of seroconversion with development of IgG antibodies in paired acute and convalescent sera supports the diagnosis of primary CMV infection. However, some immunocompromised patients may fail to mount a normal antibody response, transfusion recipients can acquire exogenous antibody that is detected on serologic testing, and some patients can periodically develop IgM antibody responses during bouts of limited reactivation of the virus. Finally, IgM antibodies can persist for weeks to months, in some cases, long after the patient has recovered from the primary infection.
Interpreting Routine Microbiology Results for Patient Care
Nancy Khardori in Bench to Bedside, 2018
When it is too difficult to isolate an organism, antibody testing may be used to establish a diagnosis. Clinicians can also use serology to assess need for and response to vaccination. It is important to know that a positive serologic test by itself does not establish a diagnosis of an active infection. In the diagnosis of syphilis, a treponemal test (such as Syphilis IGG) must be used in combination with a nontreponemal test (such as Rapid Plasma Reagin, RPR) to identify active syphilis vs. presence of antibodies due to prior exposure and treatment (Workowski and Bolan 2015). Additionally, a positive IGG may persist for life as happens after infectious mononucleosis with a positive EBV VCA IGG. Repeatedly testing for this or evaluation by a specialist for high titers is not typically warranted. As with all other microbiology testing, the results of serology testing must be evaluated in the context of patient symptoms and physical examination findings. When serology is used in acute infections such as certain tick borne and viral infections, a 4-fold increase in titers in convalescent serum can help ascertain the diagnosis (Baron et al. 2013).
Histoplasma capsulatum
Rossana de Aguiar Cordeiro in Pocket Guide to Mycological Diagnosis, 2019
In the absence of mycological methods, serology is an important tool for the presumptive diagnosis of histoplasmosis, since it indirectly evaluates the existence of the pathogen in the host through the detection of antibodies and/or antigens, as well having a rapid turnaround time, providing information indicative not only for diagnosis but also for monitoring the patient's course (Scheel & Gómez, 2014). There are many advantages to the use of serology for diagnosis of invasive fungal infection, including histoplasmosis. First, results may be positive when cultures are negative or clinical samples are difficult to obtain. Second, if positive, results of serology may reduce the requirement for culture of potentially hazardous fungi, and, finally, serology requires non-invasive clinical specimens. Sensitivity and specificity of some serologic tests could be a disadvantage of serology. A negative serologic test should not exclude the presence of fungal infection; false positives may occur with some tests in the setting of others endemic fungal infections. The sensitivity is dependent on the type of disease and the timing of testing relative to the disease process (Kozel & Wickes, 2014).
Current approaches to visceral leishmaniasis treatment in solid organ transplant recipients
Published in Expert Review of Anti-infective Therapy, 2018
Wanessa Trindade Clemente, Paulo Henrique Orlandi Mourão, Jose María Aguado
The definitive method for the confirmation of a diagnosis is the demonstration of parasites in the bone-marrow or in spleen aspirates. The sensitivity of microscopy varies from 53% to 86% in bone marrow aspirates and over 90% in splenic samples. Molecular techniques allow even greater sensitivity with the advantage of being less invasive procedures, as they can be performed using peripheral blood. Additionally, quantitative PCR can play an important role in monitoring the response to treatment. On the other hand, culture is time demanding, costly, and can take several weeks, limiting its impact on clinical decisions. The most widely used serological techniques are the indirect fluorescent antibody test, enzyme-linked immunosorbent assay (ELISA), and rapid tests, such as the immunochromatographic and direct agglutination tests. Sensitivity and specificity vary between the methods and antigens used. Antigens that are more specific, such as rK39, have been used in both ELISAs and rapid tests to improve the performance of these assays, but neither can be used for diagnostic confirmation in the absence of symptoms. Furthermore, serology assays should be supported by clinical correlation. In general, treatment is only recommended when the patient presents with a compatible clinical syndrome and laboratory evidence of VL [4–11].
Bayesian compartmental model for an infectious disease with dynamic states of infection
Published in Journal of Applied Statistics, 2019
Marie V. Ozanne, Grant D. Brown, Jacob J. Oleson, Iraci D. Lima, Jose W. Queiroz, Selma M. B. Jeronimo, Christine A. Petersen, Mary E. Wilson
This analysis is based on historical data; the original study was published by Lima et al. in 2012. During the months of January-February and June-July 2006, a study was conducted in Parnamirim, a city of 180,000 located next to Natal, to determine the covariates that were significantly associated with disease state. Households were chosen according to a random point process; 345 individuals were included in the study. Skin and serology tests were administered once to each study participant, and these test results were used to group people into infection status categories. These tests included an ELISA SLA serology test (SLA24].
Can nanotechnology help in the fight against COVID-19?
Published in Expert Review of Anti-infective Therapy, 2020
Gabriela Palestino, Ileana García-Silva, Omar González-Ortega, Sergio Rosales-Mendoza
In this regard, the FDA (USA) has approved 33 test kits for detecting SARS-CoV-2 [26]. 32 of them are based on molecular technology and only one in the serology of IgM and IgG. A rapid test based on IgM/IgG for COVID-19 diagnosis has been recently reported [9]. However, the assay presented low sensitivity (86.66 %) when compared to rRT-PCR and LAMP [9]. Further studies using the principles of serology tests have been recently conducted; some of these tests may move forward to approval for diagnostic use, while others may be appropriate for research only. Nevertheless it is important to mention that most of them have been approved for research only, which indicates that they are not approved for use as a public health diagnostic tool or for at-home diagnosis. Table 2 summarizes some of the recent test kits approved for the detection of SAR-CoV-2.
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