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
GLOBE SCIENTIFIC, LLC

Download Mobile App




New Technique Uses Dried Blood Spots to Detect Typhoid Infection More Quickly and Accurately

By LabMedica International staff writers
Posted on 01 Jul 2022

The World Health Organization (WHO) estimates that 11 to 20 million people get sick from typhoid, and between 128,000 and 161,000 people die from it every year. More...

The life-threatening infection is caused by the bacterium Salmonella Typhi and is usually spread through contaminated food or water. It is most common in parts of the world with poor sanitation. The WHO recommends typhoid vaccines to control endemic and epidemic typhoid fever. Many countries lack the infrastructure to conduct comprehensive typhoid testing, particularly in rural areas. As a result, the incidence in Bangladesh, Nepal, Pakistan and other countries may be significantly undercounted, making it difficult to develop effective vaccination strategies. Now, a new technique for detecting typhoidal Salmonella infections can significantly help vaccination planning in countries where typhoid is prevalent.

The new approach developed by an international team of researchers, including investigators at UC Davis (Sacramento, CA, USA), detects typhoid antibodies in dried blood spots. It is faster and more accurate than blood cultures and simplifies disease detection in remote areas. In a collaborative effort, researchers from Bangladesh, Nepal, Pakistan, Ghana, Canada, South Korea, England and Germany came together to develop a tool that relies on antibody responses from dried capillary blood samples. The blood is collected using a finger prick, similar to the small amount used for a blood glucose monitor. This assay is easy to perform, can be readily accomplished in remote, rural areas and is far more accurate than blood cultures.

To develop this technology, the team collected blood spots from 1,420 people with confirmed typhoid infections in Bangladesh, Ghana, Nepal and Pakistan. They tested the samples for antibody responses against two antigens: Hemolysin E (Hlye) and Salmonella lipopolysaccharide (LPS). The researchers showed the antibody responses to both HlyE and LPS persisted for months after infection, making these antibodies excellent biomarkers to measure typhoid incidence. In addition, the researchers developed algorithms to determine when a person contracted typhoid, allowing them to measure the disease’s incidence in populations over time. To accomplish this, they measured antibody responses in a population-based sample of 1,740 children and young adults in Nepal, Pakistan, Bangladesh and Ghana. When comparing their results to existing blood culture data, they found that the true number of typhoid infections was much higher across countries and regions.

Current typhoid estimates generally come from capital cities, often the only areas with blood culturing capabilities. This leaves large regions where public health officials can only guess disease prevalence. In addition to providing more comprehensive information outside cities, the new method can also pinpoint subpopulations with high percentages of typhoid in urban areas. While the study is limited to typhoid, the researchers believe this approach could be applied to other infectious diseases, revolutionizing how nations conduct epidemiological surveillance.

“Instead of just taking a sample, looking at the person's antibody response and saying they're negative or positive, we can model the antibody decay,” said Kristen Aiemjoy, an assistant professor in the Division of Epidemiology, Department of Public Health Sciences at UC Davis, and first author of the study. “We use that decay rate to infer when those people were most likely exposed, which provides vital information about the force of infection.”

“This is a big jump for typhoid surveillance, but it's also a big methodological jump in seroepidemiology,” added Aiemjoy. “We are now planning on applying this to other infectious diseases like scrub typhus and melioidosis.”

Related Links:
UC Davis 


Gold Member
Serological Pipet Controller
PIPETBOY GENIUS
Serological Pipet Controller
PIPETBOY GENIUS
New
Urine Drug Test
Instant-view® Phencyclidine Urine Drug Test
New
Droplet Digital PCR System
QX600 AutoDG
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








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: Switching to an experimental drug after liquid biopsy detection of breast cancer recurrence can improve outcomes (Photo courtesy of Shutterstock)

Treatment Switching Guided by Liquid Biopsy Blood Tests Improves Outcomes for Breast Cancer Patients

Standard treatment for patients with advanced estrogen receptor (ER)-positive, HER2-negative breast cancer, a subtype driven by estrogen receptors that fuel tumor growth, often involves aromatase inhibitors,... Read more

Pathology

view channel
Image: A new at-home self-collection device aims to reduce the screening gap for cervical cancer (Photo courtesy of CU School of Medicine)

New At-Home Cervical Cancer Screening Device to Increase Accessibility for Patients

Cervical cancer is typically linked to certain types of human papillomavirus (HPV), which is passed through sexual contact. While many people are infected with HPV, only a small percentage will develop... Read more

Technology

view channel
Image: The machine learning-based method delivers near-perfect survival estimates for PAC patients (Photo courtesy of Shutterstock)

AI Method Predicts Overall Survival Rate of Prostate Cancer Patients

Prostate adenocarcinoma (PAC) accounts for 99% of prostate cancer diagnoses and is the second most common cancer in men globally after skin cancer. With more than 3.3 million men in the United States diagnosed... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.