Targeted screening strategies to detect Trypanosoma cruzi infection in children.
BACKGROUND
Millions of people are infected with Trypanosoma cruzi, the causative agent of Chagas disease in Latin America. Anti-trypanosomal drug therapy can cure infected individuals, but treatment efficacy is highest early in infection. Vector control campaigns disrupt transmission of T. cruzi, but without timely diagnosis, children infected prior to vector control often miss the window of opportunity for effective chemotherapy.


RESULTS
We performed a serological survey in children 2-18 years old living in a peri-urban community of Arequipa, Peru, and linked the results to entomologic, spatial and census data gathered during a vector control campaign. 23 of 433 (5.3% [95% CI 3.4-7.9]) children were confirmed seropositive for T. cruzi infection by two methods. Spatial analysis revealed that households with infected children were very tightly clustered within looser clusters of households with parasite-infected vectors. Bayesian hierarchical mixed models, which controlled for clustering of infection, showed that a child's risk of being seropositive increased by 20% per year of age and 4% per vector captured within the child's house. Receiver operator characteristic (ROC) plots of best-fit models suggest that more than 83% of infected children could be identified while testing only 22% of eligible children.


CONCLUSIONS
We found evidence of spatially-focal vector-borne T. cruzi transmission in peri-urban Arequipa. Ongoing vector control campaigns, in addition to preventing further parasite transmission, facilitate the collection of data essential to identifying children at high risk of T. cruzi infection. Targeted screening strategies could make integration of diagnosis and treatment of children into Chagas disease control programs feasible in lower-resource settings.
Levy
Michael Z
MZ
Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. mzlevy@gmail.com
Kawai
Vivian
V
Bowman
Natalie M
NM
Waller
Lance A
LA
Cabrera
Lilia
L
Pinedo-Cancino
Viviana V
VV
Seitz
Amy E
AE
Steurer
Frank J
FJ
Cornejo del Carpio
Juan G
JG
Cordova-Benzaquen
Eleazar
E
Maguire
James H
JH
Gilman
Robert H
RH
Bern
Caryn
C
D000293:Adolescent; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D001499:Bayes Theorem; D014355:Chagas Disease / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology; D010568:Peru / Q000453:epidemiology; D012372:ROC Curve; D012698:Serologic Tests / Q000379:methods*; D014225:Triatominae / Q000469:parasitology; D014349:Trypanosoma cruzi / Q000302:isolation & purification*
D000913:Antibodies, Protozoan