Comparison of Giardia lamblia Infection Status in Asymptomatic and Symptomatic Pediatric Heart Transplant Patients: A Parasitic Infection Assay.

Background: Giardiasis is one of the opportunistic infections in immunocompromised patients, especially among organ transplant recipients.

Objective: This study aimed to investigate the prevalence of Giardia lamblia infection in children with heart transplantation.

Methods: A prospective cross-sectional study was conducted on 53 heart transplant recipients (aged 1-17 years). Transplant patients were on oral Trimethoprim/Sulfamethoxazole (TMP-SMX) from the first day of transplantation as a prophylaxis regimen. The prevalence of Giardia lamblia was evaluated on stool samples by phenotypic assay and polymerase chain reaction (PCR) method.

Results: Out of 53 patients studied, 11 (20.75%) had gastrointestinal symptoms, and 42 (79.25%) were asymptomatic cases. No significant difference was observed between patients with and without gastrointestinal symptoms regarding type of heart disorders (p=0.13). The overall prevalence of Giardia lamblia infection among heart transplant patients was 5.7% (n=3). Moreover, the frequency was different between gastrointestinal symptomatic and asymptomatic recipients (27.27% and 0%, respectively). All three patients whose stool exams were phenotypically positive for Giardia lamblia were confirmed with PCR. Out of three, two Giardia lamblia isolates were found to have genotype B, while one isolate had genotype A. All of the Giardia positive patients suffered from chronic diarrhea and anorexia. Cryptosporidium spp., Isospora belli and Blastocysts spp. were not found in these cases.

Conclusion: The incidence of Giardia lamblia infection in pediatric heart transplant patients is considerable and should be noted. A comprehensive guideline for the assessment of Giardia lamblia before and after transplantation is suggested.