Letters from Maine

The double-edged sword


 

Veterinarians and farmers have known it for decades. If you give a herd or flock antibiotics, its members grow better and have a better survival rate than an equivalent group of unmedicated animals. The economic benefits of administering antibiotics are so great that until very recently the practice has been the norm. However, the “everything organic” movement has begun to turn the tide as more consumers have become aware of the hazards inherent in the agricultural use of antibiotics.

Zanzibar, Tanzania  Group of young African children, black boys and girls playing in the yard in the evening, a fishing village on the island of Zanzibar, East Africa. Grigorev_Vladimir/iStock Editorial/Getty Images
Physicians continually are reminded that we should use antibiotics only when we have determined that they are warranted to treat a specific condition. Prophylaxis is frowned upon and a practice to be applied only when there is a demonstrated benefit of significant magnitude. To do otherwise opens a Pandora’s box, thereby releasing a flock of miseries and unintended consequences, foremost of which is the emergence of resistant strains of bacteria that can threaten the population we are committed to protecting.

Following this conservative and prudent party line can be difficult, and few of us can claim to have never sinned and written a less-than-defensible prescription for an antibiotic. However, for physicians who work in places where the mortality rate for children under age 5 years can be as high as 25%, the temptation to treat the entire population with an antibiotic must be very real.

When decreased early-childhood mortality was observed in several populations that had been given prophylactic azithromycin for trachoma, a group of scientists from the University of California, San Francisco, were prompted to take a longer look at the phenomenon (“Azithromycin to Reduce Childhood Mortality in Sub-Saharan Africa,” N Engl J Med. 2018 Apr 26;378[17]:1583-92). Almost 200,000 children aged 1 month to 5 years in Niger, Malawi, and Tanzania were enrolled in the study. Half received a single dose of azithromycin every 6 months for 2 years. Overall, the mortality rate was 14% lower in the experimental group (P less than .001) and 25% lower in the children aged 1-5 months. Most of the effect was observed in Niger where only one in four children live until their fifth birthday.

Like any good experiment, this study raises more questions than it answers. Will the emergence of antibiotic resistance make broader application of the strategy impractical? Keenan et al. refer to previous trachoma treatment programs in which resistance occurred but seemed to recede when the programs were halted. What conditions were being treated successfully but blindly? Respiratory disease, diarrhea illness, and malaria are most prevalent and are the likely suspects. The authors acknowledge that more studies need to be done.

Dr. William G. Wilkoff practiced primary care pediatrics in Brunswick, Maine, for nearly 40 years.

Dr. William G. Wilkoff

Giving prophylactic antibiotics to an entire population is clearly a double-edged sword. How does one develop criteria for choosing which populations will benefit enough to put its members and its neighbors at risk for antibiotic resistance? That the children of Niger benefited most suggests there might be some threshold effect that could be determined. Who should be making the decision about which populations to treat? Money wasn’t a problem in this study thanks to the Bill and Melinda Gates Foundation.

And of course, we must remember that, when it comes to antibiotic resistance, ultimately we are all neighbors.

Dr. Wilkoff practiced primary care pediatrics in Brunswick, Maine, for nearly 40 years. He has authored several books on behavioral pediatrics, including “How to Say No to Your Toddler.” Email him at pdnews@mdedge.com.

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