IgG+ in chronic infections or after previous e
posure
Rapid and inexpensive
Antibodies from prior exposure and cross-reactivity limit specificity
Insensitive in acute disease
Lateral flow Late
agglutination
Dengue
Hepatitis B
Hepatitis C
HIV
Syphilis
Antigen
Direct detection of pathogen antigens
Detected in acute/active infection
Rapid and inexpensive
Less sensitive than nucleic acid testing
Does not provide type/strain information
Lateral flow
Late
agglutination
Solid phase “dipstick”
Dengue
Ebola
HIV
Influenza
Malaria
SARS-CoV-2
Nucleic acid (RNA or DNA)
Sensitive and specific in acute phase
Can provide quantitative information
Expensive
Requires specific instrumentation
Longer performance time
PCR/RT-PCR
LAMP/RT-LAMP
RPA/RT-RPA
Chlamydia
Multiple
respiratory and gastrointestinal panels
SARS-CoV-2
Abbreviations: LAMP, loop-mediated amplification; PCR, polymerase chain reaction; RPA, recombinase polymerase amplification; RT, reverse transcription; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2
RDTs, including multiplex molecular panels ( Table 11-06 and Table 11-07 ), are available for many common clinical syndromes among travelers, the etiologies of which can overlap substantially with those of non-travel–associated syndromes. Thus, clinics might augment RDT diagnosis of common pathogens with specialized or follow-up testing for rare pathogens or positive results.
In general, RDTs for antigen and antibody detection are less sensitive than standard laboratory assays. Rapid HIV tests that use blood and cheek swab samples are widely available and perform well in identifying individuals with chronic infections. Even later-generation antigen/antibody tests remain less sensitive than molecular testing for acute HIV infection, however, and in high-risk patients, molecular testing or repeat testing is warranted. The sensitivity of rapid antigen tests for influenza and certain gastrointestinal pathogens (e.g., norovirus, rotavirus) are notably poor. Negative results should not dictate therapy decisions, and positive results should be confirmed with molecular testing.
Multiplex molecular panels are becoming more common for central nervous system (CNS), gastrointestinal, and respiratory infections, and new panels are under evaluation for febrile returning travelers. These panels often are very sensitive and can test for many pathogens in a single sample. These tests are expensive, however, and results must be interpreted in the clinical context; certain pathogens might require additional testing when there is high clinical suspicion. Notably, available multiplex assays do not test for common bacterial causes of pneumonia. Also, detection of emerging or novel pathogens is not feasible with large, preconstructed testing panels. When interpreting results provided by multiplex molecular panels, consider the prolonged shedding periods of certain pathogens, the possibility of multiple positive results or co-infections, the detection of asymptomatic carriage, and the variable accuracy for different agents on the panel (e.g., cryptococcus in CNS panels, adenovirus in respiratory panels).
Undifferentiated acute febrile illness is a common and potentially life-threating clinical presentation among returning travelers that poses a diagnostic challenge and requires prompt evaluation, diagnosis, and management. RDTs might be unavailable or insufficient to diagnose the many possible causes of febrile illness. For example, a commercial RDT for malaria has been cleared for use in hospitals and laboratories but not for individual clinics; microscopy is still the diagnostic tool of choice in malaria cases to identify the species and calculate the level of parasitemia (see Sec. 5, Part 3, Ch. 16, Malaria ). Furthermore, patients with malaria can be co-infected with other pathogens that can contribute to and complicate diagnosis and management. RDTs are not available in the United States for other common causes of undifferentiated acute febrile illness in travelers (e.g., dengue, leptospirosis).
SYNDROME | PATHOGENS | SPECIMEN TYPES | ADDITIONAL INFORMATION |
---|---|---|---|
SYSTEMIC FEBRILE ILLNESS | Dengue virus | Serum | Not FDA-cleared; highly variable performance; antibodies may cross-react between flaviviruses |
| Ebola virus | Whole blood | Received Emergency Use Authorization from FDA and Emergency Use Listing from WHO |
| spp. | Whole blood | Best performance characteristics for infections |
GASTROINTESTINAL INFECTIONS |
| Stool sample | Not FDA-cleared; may be accurate for O1- and/or O139-positive strains |
| Norovirus, rotavirus | Stool sample | Available in the United States separately or in combination |
RESPIRATORY INFECTIONS | Influenza virus | Nasopharyngeal or throat swab | Rapid test sensitivity 50%–70%; negative testing should not direct treatment |
| SARS-CoV-2 | Nasal or nasopharyngeal swabs | RDT and “at home” test availability increasing; performance with variants under investigation |
SEXUALLY TRANSMITTED INFECTIONS | and | Urine, vaginal swab | Molecular tests remain gold standard; a sample-to-answer molecular assay is available |
| HIV | Whole blood, oral fluids | Antibody and antibody/antigen kits available; molecular testing preferred for acute infection |
|
| Whole blood | Antibody detection; may not be appropriate for acute infection |
Abbreviations: FDA, US Food and Drug Administration; IDSA, Infectious Disease Society of America; RDT, rapid diagnostic test; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; WHO, World Health Organization
SYNDROME | PATHOGENS | SPECIMEN TYPES | ADDITIONAL INFORMATION |
---|---|---|---|
ACUTE FEBRILE ILLNESS | Bacteria, viruses, and parasites from different regions | Whole blood | Research use only; clinical performance for many targets has not been determined. |
GASTROINTESTINAL PATHOGENS | Includes common bacteria, viruses, and parasites | Stool sample | Sensitive; certain positive results might be unrelated to active infection. |
MENINGITIS & ENCEPHALITIS | Includes common bacteria, viruses, and fungi | CSF | Not a replacement for CSF bacterial culture; negative results do not exclude an infectious etiology of meningitis or encephalitis. |
RESPIRATORY PATHOGENS | Includes atypical bacteria, common viruses, and SARS-CoV-2 | Nasopharyngeal swab | Pathogens can have prolonged shedding time; positive results might not rule out infection from other pathogens. |
Abbreviations: CSF, cerebrospinal fluid; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2
High demand for diagnostics for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), combined with an emphasis on decreasing exposures to people infected with the virus, led the US Food and Drug Administration (FDA) to issue an Emergency Use Authorization for several RDTs and multiplex panels that include SARS-CoV-2. RDTs include rapid antigen diagnostics and the first molecular diagnostic for home use. These can be performed with self- or caregiver-collected samples. Some home test kits require that users download a smartphone application that provides test interpretation for the user and reports de-identified data for public health surveillance. These diagnostic kits perform best in symptomatic people; results in asymptomatic people should be interpreted with caution.
People who become ill while traveling might seek medical care abroad; development and availability of RDTs for diagnosis of tropical infectious diseases has expanded greatly in recent years, and travelers might return home having been diagnosed based on results from these tests. RDTs for tropical infections typically are lateral-flow immunochromatographic tests that detect antigens from or antibodies to certain pathogens. Because only 1 such test (for malaria) is cleared for use in the United States, the diagnostic characteristics of RDTs used overseas are unfamiliar to most providers. Additionally, a variety of RDTs might be available for certain pathogens (e.g., dengue) in other countries, with widely varying or poorly studied performance characteristics. Institutions that do not have continuous access to a single brand of test further complicates interpretation of results provided by the laboratory.
The following is an illustrative, though by no means exhaustive, list of several common infections for which RDTs are available.
Dengue. Rapid, lateral-flow assays are available to detect the dengue nonstructural protein 1 (NS1) antigen, and IgM and IgG. Dengue tests have widely variable performance characteristics depending on the manufacturer, circulating dengue types, a patient’s past medical history, and symptom duration.
Emerging Infections. Emerging pathogens represent a diagnostic challenge. Rapid assays became available after outbreaks of chikungunya, Ebola, and Zika. Such assays might not be available or well-studied at the peak of an outbreak, however.
Leishmaniasis. Assays to detect antibodies against the rK39 antigen (visceral leishmaniasis) have demonstrated good specificity in endemic regions, and highest sensitivity for detecting disease in South Asia.
Leptospirosis. Because of the many pathogenic and intermediate Leptospira serotypes that result in human disease worldwide, the usefulness of serologic assays for diagnosing leptospirosis is limited.
Malaria. An FDA-cleared RDT for malaria is available, and malaria RDTs are widely used throughout the world. In general, these tests perform best for Plasmodium falciparum , with variable or poor performance for other Plasmodium species.
Typhoid. Rapid serologic tests have demonstrated only moderate accuracy to diagnose typhoid. Additionally, these tests are designed to detect Salmonella enterica serotype Typhi only.
The number of assays compatible with POC testing will undoubtedly continue to increase. Building upon testing milestones achieved during the COVID-19 pandemic, “at home” testing, including molecular testing, is expected to increase in the coming years for both respiratory viruses and other pathogens. Because of the wide breadth and diversity of infecting pathogens in returned travelers, use of POC testing for nondomestic infectious diseases might not be practical for most centers once test volume, personnel training, and cost are taken into consideration. POC testing for common syndromes that affect travelers and nontravelers alike (e.g., respiratory tract and gastrointestinal infections) could provide rapid diagnosis, inform triage decisions, and limit unnecessary laboratory testing.
The following authors contributed to the previous version of this chapter: Elizabeth Rabold, Jesse Waggoner
Babady NE. The FilmArray respiratory panel: an automated, broadly multiplexed molecular test for the rapid and accurate detection of respiratory pathogens. Expert Rev Mol Diagn. 2013;13(8):779–88.
Centers for Disease Control and Prevention. Ready? Set? Test! Patient testing is important. Get the results right. Atlanta: The Centers; 2019. Available from: www.cdc.gov/labquality/images/waived-tests/RST-Booklet_Dec-2019.pdf .
Gonzalez MD, McElvania E. New developments in rapid diagnostic testing for children. Infect Dis Clin North Am. 2018;32(1):19–34.
Hunsperger EA, Yoksan S, Buchy P, Nguyen VC, Sekaran SD, Enria DA, et al. Evaluation of commercially available diagnostic tests for the detection of dengue virus NS1 antigen and anti-dengue virus IgM antibody. PLoS Negl Trop Dis. 2014;8(10):e3171.
Infectious Disease Society of America. IDSA practice guidelines. Available from: www.idsociety.org/practice-guideline/practice-guidelines .
Pai NP, Vadnais C, Denkinger C, Engel N, Pai M. Point-of-care testing for infectious diseases: diversity, complexity, and barriers in low- and middle-income countries. PLoS Med. 2012;9(9):e1001306.
US Food and Drug Administration. CLIA—Clinical Laboratory Improvement Amendments—currently waived analytes. Available from: www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfClia/analyteswaived.cfm .
US Food and Drug Administration. In vitro diagnostics EUAs. Available from: www.fda.gov/medical-devices/coronavirus-disease-2019-covid-19-emergency-use-authorizations-medical-devices/in-vitro-diagnostics-euas .
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VIDEO
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Now that we know the Advantages and Disadvantages of Presentations, we will provide you with some tips on how to make a successful Presentation. 1) Know your audience: Understand your audience's needs and interests to tailor your content accordingly. 2) Start with a strong opening: Begin with an attention-grabbing introduction to captivate the ...
Immediate Feedback: Oral communication allows for immediate feedback, enabling instant clarification, confirmation, or adjustment of messages in real time, leading to better understanding and resolution of issues.This highlights oral communication advantages. Personal Connection, an oral communication advantage, Oral communication is often vital for successful interactions and collaborations ...
Time-Saving. Oral communication is a time-saving device. While a letter, dictate and typed, entered in the diary, put in the envelope, and carried to the person addressed will take a long time, oral transmission of the message makes the communication immediately effective.
Key advantages of the oral communication approach: 1/ Immediate Feedback: One of the most significant merits of oral communication is the ability to receive immediate feedback while communicating.In face-to-face or real-time interactions, both the sender and the receiver can quickly determine each other's reactions, understand the message's clarity, and address any misunderstandings promptly.
What are the advantages and disadvantages of Oral Communication. The following are the advantages and disadvantages of Oral Communication: Advantages ... Public speaking involves delivering a speech or presentation to a large audience, and oral communication is essential in delivering an effective speech or presentation. Also check: Speech on ...
What is Oral Communication? Oral communication is transfer of information from sender to receiver by means of verbal and visual aid. Examples of oral communication include presentations, speeches, discussions, etc. Though the message is conveyed through words, most of the times oral communication is effectively carried out with the help of non-verbal communication like body language and tone ...
Advantages and disadvantages of Oral Communication Time-saving. Where rapid action is necessary, in that case, it is the best way to send a message orally. On the other handwritten communication takes a long time to reach the sender. But oral communication through telephone calls or conversations with subordinates makes savings time which is so ...
Best Answer. Advantages: • Oral test provides direct contact between the teacher and the student. • More than one teacher can assess more than one student simultaneously. • It provides an ...
Oral communication contains many advantages. In spite of this, there are oral some disadvantages which are given below: No record: In oral communication, messages are difficult to record. So it is impossible to preserve the message for the future. Expensive: It is also expensive media of communication.
Conversations with friends, relatives, or coworkers, as well as presentations and speeches, are examples of oral communication. Although words are used to convey the message, nonverbal communication such as body language and tone modulations are frequently used to enhance spoken communication.
Oral Presentations Vs Written Presentation. Courtesy Ryan Jerving. Communication - the way you speak, the way you write, even the way you carry yourself each carry a great deal of power. They each allow you to reach an audience and deliver a message. When you are called upon to deliver a presentation you will find yourself faced with a decision.
• Teach oral presentations skills and start early in the academic term. • Provide tips and handouts in your course syllabi or electronic (e.g Angel, Blackboard) pick-up box. • Schedule an oral presentation rehearsal on basic tips on visual aids, dress, timing, content and oral presentations objectives.
What are the characteristics of oral presentation? Features of an Oral Presentation. Preparation. A strong oral presentation begins with sound research, regardless of topic. Delivery. After preparing the information, practice delivering the presentation. Audience. The audience is the least predictable feature of an oral presentation. Visuals.
visually based presentations. speaker might lose track. speaker might leave something out. Chapter 23 Advantages and Drawbacks of Oral Presentations. Advantages of Presentations. Click the card to flip 👆. Body Language to establish credibility. (vocal tone, eye contact, gestures) Give-and-Take.
Ultimately, the presenter wants to add verbal content to the visual presentation such as examples and anecdotes to round out the presentation. Technical difficulties can get in the way of success — When a presenter relies too heavily on visual presentations to communicate their message, panic can set in when there is an audio-visual glitch.
What are the disadvantages of presentation? The disadvantages of presentations include: the message is only heard once at the pace of delivery set by the speaker; some people may be unable to attend; and the effectiveness relies very much on the ability of the speaker.
Your oral presentation to the board of directors will outline the advantages and disadvantages of merging with another company. The problem-solution organizational plan would probably be best for this topic. ... In the U.S., for example, blue is a popular color choice for many presentations because it is associated with credibility, tranquility ...
Advantages of Oral Communication • There is high level of understanding and transparency in oral communication as it is interpersonal. • There is no element of rigidity in oral communication. There is flexibility for allowing changes in the decisions previously taken. • The feedback is spontaneous in case of oral communication.
2. Abundant Features. PowerPoint is the most feature-rich presentation software out there. It has everything you need to create a professional-looking presentation, including built-in templates, themes, and much more. Other presentation software simply cannot compete with PowerPoint in this regard. 3.
What are the advantages of digital presentation? The Key Advantages of Online Presentations for an Online Store. Visual information. The main advantage of an online presentation is that it has a lot of visual information. Interactivity. Saves clients' time. Can be applied in many areas. Easy to create. What are the advantages of oral ...
Advantages of oral route of drug administration. 1. It is the simplest, most convenient, and safest means of drug administration. 2. It is convenient for repeated and prolonged use. 3. It can be self-administered and pain-free. 4. It is economical since it does not involve the patient in extra cost.
(30)(C) interpret and create written, oral, and visual presentations of social studies information ; and (30)(D) apply foundational language skills to engage in civil discourse about social ... options, consider advantages and disadvantages, choose and implement a solution, and evaluate the effectivenessof the solution;
Advantages Disadvantages Format Examples; Antibody. ... Undifferentiated acute febrile illness is a common and potentially life-threating clinical presentation among returning travelers that poses a diagnostic challenge and requires prompt evaluation, diagnosis, and management. ... oral fluids. Antibody and antibody/antigen kits available ...