Chagas disease screening in pregnant Latin American women: Adherence to a systematic screening protocol in a non-endemic country

BACKGROUND

Chagas disease (CD) is a chronic parasitic disease caused by Trypanosoma cruzi and is endemic to continental Latin America. In Spain, the main transmission route is congenital. We aimed to assess adherence to regional recommendations of universal screening for CD during pregnancy in Latin American women in the province of Alicante from 2014 to 2018.

METHODOLOGY/PRINCIPAL FINDINGS

Retrospective quality study using two data sources: 1) delivery records of Latin American women that gave birth in the 10 public hospitals of Alicante between January 2014 and December 2018; and 2) records of Chagas serologies carried out in those centers between May 2013 and December 2018. There were 3026 deliveries in Latin American women during the study period; 1178 (38.9%) underwent CD serology. Screening adherence ranged from 17.2% to 59.3% in the different health departments and was higher in Bolivian women (48.3%). Twenty-six deliveries (2.2%) had a positive screening; CD was confirmed in 23 (2%) deliveries of 21 women. Bolivians had the highest seroprevalence (21/112; 18.7%), followed by Colombians (1/333; 0.3%) and Ecuadorians (1/348; 0.3%). Of 21 CD-positive women (19 Bolivians, 1 Colombian, 1 Ecuadorian), infection was already known in 12 (57.1%), and 9 (42.9%) had already been treated. Only 1 of the 12 untreated women (8.3%) was treated postpartum. Follow-up started in 20 of the 23 (87.0%) neonates but was completed only in 11 (47.8%); no cases of congenital transmission were detected. Among the 1848 unscreened deliveries, we estimate 43 undiagnosed cases of CD and 1 to 2 undetected cases of congenital transmission.

CONCLUSIONS/SIGNIFICANCE

Adherence to recommendations of systematic screening for CD in Latin American pregnant women in Alicante can be improved. Strategies to strengthen treatment of postpartum women and monitoring of exposed newborns are needed. Currently, there may be undetected cases of congenital transmission in our province.

Rapid identification and antimicrobial susceptibility testing of Gram-negative rod on positive blood cultures using MicroScan panels

Shortening the turnaround time of antimicrobial susceptibility testing (AST) of bacteria permits a significant reduction of patient morbidity, mortality, and cost. Conventional blood culture methods are the gold standard diagnostic test to guide management of patient with sepsis, but the conventional process requires at least 12 to 24 h after the blood culture has been flagged as positive due to requirement for pure colonies. We describe a simple and inexpensive method to obtain faster AST with MicroScan system (Beckman Coulter) directly from positive blood cultures. Conventional and direct identification and AST were performed simultaneously by both methods in 1070 blood cultures, and 9106 MICs were determinated. About 96.5% were correctly identified with the direct method. Overall, categorical agreement was 92.86%. We found 46 very major errors, but globally the results showed a good correlation with the standard method, particularly favorable for E. coli and K. pneumoniae, except amoxicillin-clavulanate and piperacillin-tazobactam. For P. mirabilis, betalactams antibiotics (except second- and third-generation cephalosporines) showed a good correlation, and also a good correlation was found for ciprofloxacine and gentamicine in P. aeruginosa and amoxicillin-clavulanate, ciprofloxacine, gentamicine, and cotrimoxazole in E. cloacae. This method has the main advantage of providing reliable results 1 day earlier, being a simple, fast, and cheap method for identification and antimicrobial susceptibility testing results from positive blood cultures.

Performance of the cobas u 701 Analyzer in Urinary Tract Infection Screening

Background

Negative urine cultures to rule out urinary tract infections (UTI) generate a considerable laboratory workload; thus, a rapid screening test is desirable. We evaluated the performance of a new automated microscopy analyzer, cobas u 701 (Roche Diagnostics International, Rotkreuz, Switzerland) for the screening of UTI, and developed a rule-out strategy to reduce the number of samples requiring culture. We also assessed squamous epithelial cell (SEC) count as a predictor of culture contamination.

Methods

In total, 1,604 urine samples from outpatients were analyzed with cobas u 701 and culture. Bacterial (BAC) and white blood cell (WBC) counts were used for sample interpretation. To determine a useful cut-off point to predict negative cultures, we selected the highest sensitivity and specificity values obtained from ROC curves. Diagnostic accuracy by age and gender was evaluated.

Results

Urine culture showed growth of ≥10⁴ colony forming units (CFU)/mL in 256 samples (16.0%). The highest sensitivity (91.8%) and specificity (68.4%) were obtained for cut-off points of 119 BAC/µL and 22 WBC/µL. The combination of BAC and WBC improved the performance of the rule-out strategy with a low rate of false-negative results (1.5%) and a high negative predictive value (NPV, 97.3%). Fifty-seven percent of the samples would not have required culture. SEC count was a poor predictor of culture contamination.

Conclusions

cobas u 701 can substantially reduce the number of urine samples requiring culture, with a low false-negative rate and a high NPV.