C. Difficile Colonization Among Children in Resource-Limited Settings

High rates of C. difficile colonization have been documented among infants in resource sufficient settings, where C. difficile infection (CDI) rates can be as high as 90% among hospitalized neonates. Colonization decreases with increasing age until age two when rates start to mirror healthy adults. Some studies have indicated that C. difficile may be more prevalent than rotavirus or Cryptosporidium in children presenting with diarrhea to the hospital.

Infectious Disease specialists at The University of Virginia School of Medicine (Charlottesville, VA, USA) conducted a study at eight sites: Dhaka, Bangladesh; Fortaleza, Brazil; Vellore, India; Bhaktapur, Nepal; Loreto, Peru; Naushero Feroze, Pakistan; Venda, South Africa; and Haydom, Tanzania. The study ran from November 2009 through February 2014. The team tested 41,354 monthly non-diarrheal and diarrheal stools for C. difficile toxin genes (tcdA and tcdB) using quantitative polymerase chain reaction (qPCR) in 1,715 children from birth to age two years.

The QIAmp Fast DNA Stool Mini Kit (Qiagen, Venlo, The Netherlands) was used to extract total nucleic acid from the stool specimens. TaqMan Array Cards (TAC) were developed to detect 29 enteropathogens via qPCR using AgPath One Step Realtime PCR kit (Thermo Fisher Scientific, Waltham, MA, USA). The qPCR assays targeting C. difficile tcdA (enterotoxin) and tcdB (cytotoxin) genes were validated on the TaqMan Array platform, demonstrating 100% sensitivity and 100% specificity on clinical specimens using a secondary real time PCR as confirmation.

Monthly stool samples were tested for myeloperoxidase (MPO; measured in ng/m), neopterin (NEO; measured in nmol/L), and α-1-antitrypsin (AAT; measured in mg/g) and analyzed on the logarithmic scale. Serum α-1-acid glycoprotein was measured at months 7, 15, and 24 (AGP; measured in mg/dL). Lactulose/mannitol excretion ratios (LMR) were measured in urine at 3, 6, 9, and 15 months. Plasma zinc and retinol were measured at 7, 15, and 24 months.

The scientists reported that the prevalence of C. difficile detection was lower in diarrheal (2.2%; n= 151/6,731) compared to non-diarrheal stools (6.1%; n= 2106/34,623). By 24 months of age, the cumulative incidence of C. difficile varied widely by site, ranging from 17.9% (n=44; Pakistan) to 76.3% (n=148; Peru) of children having at least one positive stool. Only Bangladesh and Pakistan had seasonal differences in C. difficile detection. Female gender (adjusted risk ratio (aRR):1.18), cephalosporin use in the past 15 days (aRR: 1.73), and treated water (aRR: 1.24) were risk factors for C. difficile positivity. C. difficile carriage was significantly associated with elevated fecal myeloperoxidase, neopterin, and α-1-antitrypsin, but no associations were found between C. difficile and child growth at 24 months of age.

The authors concluded that C. difficile colonization among children ages 0-2 years was variable across low-resource settings. Significant elevation of intestinal inflammation and barrier disruption markers associated with C. difficile detection suggests subclinical impact of colonization. The study was published on February 09, 2022 in the journal Clinical Microbiology and Infection.

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