Multiple tests are needed to detect intestinal parasite infections in children who were adopted from overseas – including children without gastrointestinal symptoms – according to a new study in the August issue of Pediatrics.
The study enrolled 1,042 children within 120 days of their arrival in the United States from 36 countries in Asia, Europe, Latin America, and Africa.
Of these, 27% were found to be infected with intestinal parasites (most commonly Giardia intestinalis), a rate higher than that seen in previous studies of internationally adopted children. Prevalence of infection was associated with increasing age at adoption, birth country, and history of institutionalization, but not with gastrointestinal symptoms (Pediatrics 2011 Aug. 8 [doi:10.1542/peds.2010-3032]).
Although 40% of children aged older than 1 year had a pathogen compared with 7% of those who were younger, and 34% institutionalized children had a pathogen compared with only 4% of noninstitutionalized children, the proportion of infections was the same among both the children whose parents reported diarrhea or more than three stools per day and those whose parents reported no such symptoms.
Current screening guidelines from the American Academy of Pediatrics’ online Red Book recommend that three stool samples be tested in recently adopted children who have gastrointestinal symptoms. Only one sample is deemed necessary for asymptomatic children.
However, the researchers, led by Dr. Mary Allen Staat of Cincinnati Children’s Hospital Medical Center, found that multiple tests significantly increased the likelihood of pathogen detection in children, whether or not they had symptoms. If a single stool sample was tested, the probability of identifying a pathogen was 79%. With two samples, the probability significantly increased to 92%, and for three, it was 100%.
This suggests, Dr. Staat and colleagues wrote, that the current American Academy of Pediatrics’ guidelines should be revised so that three stool specimens, taken 48-72 hours apart, "are submitted and evaluated for all internationally adopted children on arrival to the United States, regardless of gastrointestinal symptoms."
Dr. Elaine Schulte, chair of pediatrics at the Cleveland Clinic and medical director of its international adoption program, said in an interview that the findings had "important" implications for pediatricians and families of internationally adopted children. (The Cleveland Clinic’s international adoption program provides comprehensive medical care to internationally adopted children, including preadoption and postadoption consultation and ongoing care.)
"You can’t rely on kids to be symptomatic," Dr. Schulte said. "For physicians who see internationally adopted kids – but not very many – they may rely on parent assessment, which is not good. Most parents who are adopting internationally have heard about parasites, [but] that doesn’t mean they know what they are, or understand the process of detecting them."
Undiagnosed, untreated parasite infections can lead to malnutrition, and also can be contagious in school and family settings, Dr. Schulte noted. "I’ve taken care of lots of kids who just pass it back and forth among siblings, and it’s really hard to get rid of. Parents also can get infected."
Dr. Staat and her colleagues found the lowest infection rates among children born in South Korea (0%), followed by Guatemala (9%), China (13%), and Vietnam (19%). The highest rates were seen in children from Romania (50%), Bulgaria (54%), Ethiopia (55%), and the Ukraine (74%).
In addition to G. intestinalis, which was present in 19% of children in the study, identified pathogens included Blastocystis hominis (10% of children), Dientamoeba fragilis (5%), and Entamoeba histolytica (1%). Helminths (parasitic worms) were found in 2% of children.
Dr. Staat and her colleagues declared that they had no relevant financial disclosures. Dr. Schulte said that she had no relevant financial disclosures.