Antibiotic intake, misuse higher on Mexican side of U.S. border

Pediatric antibiotic use, as well as apparent misuse, was more prevalent in Mexico compared with Texas along the countries’ shared border, data from a recent study indicated.

U.S. and Canadian researchers analyzed information from the Pasitos (Baby Steps) Cohort Study from April 1998 to December 2005 to determine if the frequency of antibiotic use differed between Juarez, Mexico, and El Paso, Texas. The prevalence of antibiotics prescribed for Helicobacter pylori infection was of particular interest to the researchers.

Data from 2,938 follow-up visits were available for 602 children, according to the researchers. The mean follow-up time was 3.2 years in the United States and four years in Mexico.

Combined results indicated that the proportion of children who ever took one or more systemic antibiotic course was 79%, the researchers said, and 57% reported ever using H. pylori-effective antibiotics. Eighty-four percent of children in Juarez, however, reported receiving one or more course of antibiotics during the follow-up period, whereas 76% of children in El Paso said they received one or more course.

Conversely, the researchers noted that 65% of children in El Paso reported receiving one or more course of H. pylori-effective antibiotics as opposed to 44% among the children in Juarez. Among all H. pylori-effective antibiotic courses reported by in study cohort, 98% corresponded to amoxicillin. Metronidazole and furazolidone were used rarely and mostly in Mexico, the researchers wrote.

The most commonly cited reasons for antibiotic use were throat infections among Mexican children and ear infection among U.S. children.

Results also indicated that apparent misuse of antibiotics for conditions of probable viral cause occurred, with 31% of courses in Juarez and 15% in El Paso taken for diarrhea, stomach infections, cold or flu. Some of the apparent antibiotic misuse among U.S. children occurred with drugs purchased in Mexico, according to the researchers.

“Such misuse of antibiotics along the United States-Mexico border may lead to drug resistance and may impair the control of H. pylori infection in this region,” the researchers wrote.

Broussard CS. Pediatrics. 2010;125:e1468-e1474.

This interesting article provides a few insights into the US/Mexico cross-border differences in the practice of medicine, as well as some potential pitfalls in interpreting data based on the collection methods.

The authors suggest that misuse of antibiotics is more frequent in Mexico, as children from low-income families enrolled on both sides of the border in this study were compared, and those from Mexico received more “courses” of antibiotics.

However, the information on antibiotic use was obtained from parents, and we often have concerns about the reliability of parent recall when asked about why an antibiotic was prescribed (with interviews every six months in this study). Antibiotic "courses" appear to have been derived from courses prescribed by physicians, courses purchased over-the-counter in Mexico, as well as leftover antibiotics that the parent had given to the child. Each of these “courses” may have had different durations, and each may have had a different impact on the potential development of resistant organisms.

The authors also use parent recall of the diagnosed infection for which the antibiotics were given as the basis for an assessment of appropriate use. However, not all parents may understand the medical diagnosis at the time of a physician visit, so “inappropriate use” may have been overestimated if the parent did not cite a recognizable indication. It is also possible that the cohort in Mexico indeed had an increased number of infections based on increased exposures to pathogens in these low income families. Without review of medical charts, the increased use of antibiotics in Mexican children may have actually been appropriate.

Finally, the authors conceptually link the use of antibiotics to resistance in Helicobacter. While many organisms have been well documented to develop resistance following repeated exposure to antibiotics, a few, like Group A streptococcus, remain susceptible to penicillin after a half century of penicillin use. Amoxicillin was FDA approved 30 years ago, and has been extensively used for children as both a single agent, and in combination with clavulanic acid (Augmentin, GlaxoSmithKline). Amoxicillin remains one of the antibiotics used for primary therapy of Helicobacter in 2010 despite widespread use for all indications over the past few decades. Further, the references cited by the authors to support the increase in amoxicillin resistance specifically, do not support this concept.

Although we are all trying our best to use antibiotics only when indicated due to concerns about resistance with many pathogens, recommending amoxicillin as the drug of choice for infections such as otitis media is still reasonable despite the authors’ concerns about Helicobacter. Misuse of antibiotics cannot, unfortunately, be accurately addressed in a study of this design.

– John Bradley, MD
Infectious Diseases in Children Editorial Board

Follow the PediatricSuperSite.com on Twitter.