We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress hp
Sign In
Advertise with Us
PURITAN MEDICAL

Download Mobile App




Immunoassay Developed for Acute Typhoid Fever

By LabMedica International staff writers
Posted on 05 Jul 2017
Salmonelloses are a group of potentially fatal bacteremias caused by different serovars of Salmonella enterica. More...
Typhoid fever (TF) caused by the human-specific serovar S. typhi, is a global health problem, especially in developing countries.

Accurate diagnosis of salmonellosis remains a challenge in endemic settings. Clinically, initial presentation with typhoid or non-typhoid Salmonella (NTS) disease is usually with non-differentiating fever alone, and often without symptoms of gastroenteritis that would indicate a Salmonella infection.

An international team of scientists led by those at the University of California Irvine (Irvine, CA, USA) designed a retrospective study was using a convenience series of sera samples from Nigerian pediatric febrile cases and healthy controls, as well as other infectious diseases from other locations outside Nigeria. The Nigerian samples were collected between 2009 and 2014 from children aged eight months to 13 years (median approximately 4 years) who presented to primary or secondary health centers in central and northwest Nigeria with an acute febrile illness and other symptoms that were suggestive of bacteremia.

Blood was obtained aseptically from a peripheral vein for blood culture and simultaneously an aliquot for serum separation was saved. Bacteria were identified by morphology, and for Enterobacteriacae, by use of an API 20 E rapid identification system. Lipopolysaccharides microarrays were obtained from various species and printed on Oncyte Avid nitrocellulose-coated glass slides using an Omnigrid 100 array printer, and printed at a concentration of 0.1 μg/mL. Immunoglobulin A (IgA), IgM and IgG enzyme-linked immunosorbent assays (ELISAs) using S.enterica serovar Typhi (S. typhi) lipopolysaccharide (LPS) and hemolysin E (t1477) protein were conducted.

The scientists found that the most expedient discrimination was achieved between TF and healthy children. LPS-specific IgA and IgM provided receiver operator characteristic areas under the curve (ROC AUC) values of 0.963 and 0.968, respectively, and 0.978 for IgA+IgM combined. Similar performance was achieved with t1477-specific IgA and IgM (0.968 and 0.968, respectively; 0.976 combined). Importantly, discrimination between TF and children with other infections was maintained by LPS-specific IgA and IgM (AUC = 0.903 and 0.934, respectively; 0.938 combined), and slightly reduced for IgG (0.909), while t1477-specific IgG performed best (0.914).

The authors concluded that the key finding concerns LPS. This is a common cell-wall component present in many bacterial species. Yet despite this, S. Typhi LPS-specific IgA and IgM are excellent markers of acute TF in Nigerian children, and insensitive to other non-salmonelloses. This surprising finding suggests a rapid point-of-care test for TF can be developed based on detection of LPS-specific IgA+IgM. The study was published on June 22, 2017, in the journal Public Library of Science Neglected Tropical Diseases.

Related Links:
University of California Irvine


Gold Member
Flocked Fiber Swabs
Puritan® Patented HydraFlock®
Serological Pipet Controller
PIPETBOY GENIUS
New
Gold Member
Blood Gas Analyzer
Stat Profile pHOx
New
Automatic Hematology Analyzer
LABAS F9000
Read the full article by registering today, it's FREE! It's Free!
Register now for FREE to LabMedica.com and get access to news and events that shape the world of Clinical Laboratory Medicine.
  • Free digital version edition of LabMedica International sent by email on regular basis
  • Free print version of LabMedica International magazine (available only outside USA and Canada).
  • Free and unlimited access to back issues of LabMedica International in digital format
  • Free LabMedica International Newsletter sent every week containing the latest news
  • Free breaking news sent via email
  • Free access to Events Calendar
  • Free access to LinkXpress new product services
  • REGISTRATION IS FREE AND EASY!
Click here to Register








DIASOURCE (A Biovendor Company)

Channels

Hematology

view channel
Image: CitoCBC is the world first cartridge-based CBC to be granted CLIA Waived status by FDA (Photo courtesy of CytoChip)

Disposable Cartridge-Based Test Delivers Rapid and Accurate CBC Results

Complete Blood Count (CBC) is one of the most commonly ordered lab tests, crucial for diagnosing diseases, monitoring therapies, and conducting routine health screenings. However, more than 90% of physician... Read more

Immunology

view channel
Image: A simple blood test could replace surgical biopsies for early detecion of heart transplant rejection (Photo courtesy of Shutterstock)

Blood Test Detects Organ Rejection in Heart Transplant Patients

Following a heart transplant, patients are required to undergo surgical biopsies so that physicians can assess the possibility of organ rejection. Rejection happens when the recipient’s immune system identifies... Read more

Pathology

view channel
These images illustrate how precision oncology Organ Chips recapitulate individual patients’ responses to chemotherapy (Photo courtesy of Wyss Institute at Harvard University)

Cancer Chip Accurately Predicts Patient-Specific Chemotherapy Response

Esophageal adenocarcinoma (EAC), one of the two primary types of esophageal cancer, ranks as the sixth leading cause of cancer-related deaths worldwide and currently lacks effective targeted therapies.... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.