Flocked Swab Reveals Severe Diarrheagenic Babies Had Undiagnosed Infection

Diarrheal disease is a leading cause of death for young children and most pediatric gastroenteritis is caused by viral pathogens; consequently, current recommendations advocate against routine antibacterial therapy if children present without bloody stools.

An innovative 'flocked swab' improves diagnosis, treatment of deadly childhood diarrheal diseases and helped diagnosed previously unrecognized pathogens that had caused the severe diarrhea of over one-third of children in a group of southern Africa hospitals.


A team of scientists led by those at British Columbia Children's Hospital (Vancouver, BC, Canada) enrolled children with severe acute gastroenteritis admitted to a hospital in Botswana. Details of presenting history, physical examination, and course in the hospital were recorded. Stool samples were characterized using a 15 pathogen polymerase chain reaction assay. There were 671 participants with a median age of 8.3 months; 77 (11%) had severe acute malnutrition. Only 74 children had bloody stools, of whom 48 (65%) had a detectable bacterial pathogen, compared to 195 of 592 (33%) of those without. There were 26 deaths (3.9%).

Reverse transcription, amplification, and detection of 15 pathogen targets (three viruses, three parasites, and nine bacteria) were performed using the Gastrointestinal Pathogen Panel (GPP) assay on the MAGPIX system (Luminex Molecular Diagnostics; Toronto, Canada). The flocked rectal swab (FLOQSwab, Copan; Brescia, Italy) was used to eliminate the wait and biohazard involved in obtaining and transporting a bulk feces sample from an infant or child. This efficiency enabled implementation of a randomized clinical trial evaluating same-day diagnosis and treatment for a broad number of pathogens.

Children randomly chosen for rapid testing using the flocked swab and appropriate treatment were 55% less likely to have diarrhea recur, compared with children not chosen, and they had a clinically significant height gain after 60 days. This measure of growth is an important indicator of children's ability to reach their full developmental potential. Rotavirus was more commonly detected in younger children (42% of infants, 32% of children aged 12 to 24 months, and 12% of children aged more than 24 months), as was Campylobacter (15% of infants, 16% of children aged 12 to 24 months, and 2.0% of children aged more than 24 months). In contrast, Shigella was more often found in older children (9.6% of infants, 24% of children aged 12 to 24 months, and 47% of children aged more than 24 months as was Salmonella.

Peter Alexander Singer, OC, MD, MPH, FRSC, a professor and CEO of Grand Challenges Canada (Toronto, ON, Canada) said, “The simple fact is: Diagnostics save lives. If health workers can quickly and accurately pinpoint the cause of a child's illness, timely help can be administered, preventing many deaths and improving many lives. The flocked swab offers a shining example of the sort of 'Bold Idea with Big Impact' in global health.” The study was published on May 16, 2015, in the Journal of the Pediatric Infectious Disease Society.

Related Links:
British Columbia Children's Hospital  
Luminex Molecular Diagnostics 
Copan