Researchers discovered a wide prevalence of strongyloidiasis — a chronic intestinal infection caused by a soil-transmitted intestinal nematode — among immunocompromised patients in Bolivia.
Writing in PLOS Neglected Tropical Diseases, Laurent Getaz, MD, MPH, from the department of medicine and penitentiary psychiatry and service of tropical and humanitarian medicine at Geneva University Hospitals, and colleagues explained that infection caused by Strongyloides stercoralis is one of the most overlooked neglected tropical diseases and can lead to severe complications and high mortality rates in immunocompromised individuals.
The researchers conducted a cross-sectional study in two Bolivian cities — Cochabamba and Santa Cruz — from July 2012 to April 2013. They sought to estimate the burden of the parasite in 1,151 patients aged 18 years or older who were at high risk for complications, including those with cancer (32%), HIV (30%) and rheumatic (29%) or hematologic diseases (9%). Stool and blood samples were collected and tested for parasitology and serology using four coproparasitological techniques and one serological test, according to the study.
Getaz and colleagues said the serological prevalence of S. stercoralis was 23% (95% CI, 20.7-25.5), and the coproparasitological prevalence was 7.6% (95% CI, 6.2-9.3). The researchers estimated an actual prevalence of 20.2% (95% CI, 17.9-22.5). According to the study, younger age and lower levels of education were significantly associated with positive findings on serology and coproparasitology. Getaz and colleagues did not observe significant differences between Cochabamba and Santa Cruz. Specifically, the prevalence of coproparasitology was 6.4% in Cochabamba compared with 8.9% in Santa Cruz. Moreover, serology prevalence was 24% in Cochabamba compared with 22% in Santa Cruz.
A wide prevalence of strongyloidiasis was discovered among immunocompromised patients in Bolivia.
Source: CDC/ Dr. George R. Healy
Getaz and colleagues concluded that strongyloidiasis is “widely prevalent” in Bolivia. Transmission of the parasite that causes the infection occurs in tropical lowlands and temperate elevation, they said. Approximately 5.2% of the global population is infected with the enteric parasite, but the researchers believe this number may be underestimated due to the low sensitivity of conventional diagnostics.
Currently, albendazole is administered in primary schools as part of Bolivia’s national deworming campaign, but the drug demonstrates suboptimal efficacy for S. stercoralis, and the researchers suggested adding ivermectin to the program in areas with a high prevalence of infection.
“Because S. stercoralis is the most dangerous enteric parasite, laboratory methods sensitive for S. stercoralis must be accessible to monitor prevalence and treatment,” Getaz and colleagues wrote. “Given the high prevalence in this population, the mortality associated with [hyperinfection syndrome]/[ disseminated strongyloidiasis] and the efficacy and safety of early treatment, we recommend the presumptive use of ivermectin for patients that undergo immunosuppression, or before initiating immunosuppressive therapy.” – by Marley Ghizzone
Disclosures: The authors report no relevant financial disclosures.