Young children who reside with adults who work on large industrial (pig) operations in rural North Carolina had a higher prevalence of antibiotic-resistant Staphylococcus aureus in their nasal passages compared to children who live with adults who do not work on such operations, but live in the same community, a new study suggests.
Antibiotic resistance is a growing public health crisis, with an estimated two million people in the United States getting sick and thousands dying, according the Centers for Disease Control and Prevention.
‘The judicious use of antibiotics is imperative to prevent the deadly and unmanageable infections caused by fast emerging multidrug-resistant bacteria.’
Antibiotic-resistantáS. aureusácarriage is a concern in health care settings, including hospitals, because it can increase chances of infection and transmission to other patients. Patients are often tested for MRSA carriage so precautions can be taken.
While no children or adults participating in the study became sick, the researchers say the findings raise concerns because of how many children living with hog workers carried potentially harmful antibiotic-resistantáS. aureus--methicillin-resistantáS. aureusá(MRSA) and multidrug-resistantáS. aureusá(MDRSA) --in their noses.
The study, which will be published online in the journaláEnvironmental Health Perspectives
, also raises the question of whether the bacteria might be able to travel home on the protective clothing and equipment worn by the workers.
In Europe, studies have shown that children living with industrial hog operation workers are at risk of acquiring drug-resistant staph from their parents, carrying these strains in their noses and also developing staph infections. This has led the European Union to restrict the non-therapeutic use of antibiotics that promote pig growth to ready them for market sooner.
The use of antibiotics in livestock - as much as 80% of antibiotics sold in the United States are used in livestock production - is thought to be a contributing factor for increased antibiotic resistance. .
"Before this study, we didn't know how common it was for children living with industrial hog operation workers in North Carolina to carry antibiotic-resistantáS. aureusáin their noses. Now that we know how prevalent MRSA and MDRSA are, important next steps are to learn how children are becoming exposed and whether there are implications for their health," says study leader Christopher D. Heaney, PhD, MS, an assistant professor in the Bloomberg School's departments of Environmental Health and Engineering and Epidemiology.
Although children tend to be susceptible to developing staph infections, the researchers caution that none of the children or adults participating in the study reported becoming sick during the course of the study. They say it is too early to draw any conclusions about possible infection and transmission, but the high prevalence in children's nasal passages warrants further studies of possible connections between nasal carriage and infection.
The study, a collaboration enrolled 400 adult-child pairs in the top 10 hog-producing counties in North Carolina, the second largest hog-producing state in the United States. One set of 198 pairs included an adult who worked at an industrial hog operation and a child under age seven living in the same household. The other 202 pairs consisted of an adult community resident who did not work on any type of livestock operation and a child under age seven living in the same household. The research team collected nasal swabs from all participants during home visits between March and October 2014. Adults in both groups also completed a questionnaire about themselves and the child participating in the study.
The researchers found that 23% of children living with industrial hog operation workers were carrying MDRSA, meaning theáS. aureusáwas resistant to three or more antibiotic drug classes, as compared to 8% of children who lived with adults who were not livestock workers.
Meanwhile, 14% of children who lived with an industrial hog operation worker were carrying MRSA compared to 6% of children who lived with adults who weren't livestock workers.
The researchers also found that children who lived with an industrial hog operation worker who reported bringing home personal protective equipment such as masks, coveralls, boots and/or hats from the hog operation had a higher prevalence of carrying MRSA and MDRSA in their noses than children who lived with a hog operation worker who did not bring this equipment home.
"Our hope is that this study raises awareness about antibiotic resistantáS. aureusáexposures among children living with industrial hog operation workers and initiates more discussions about antibiotic use and resistance in communities with a high density of hog production," says study author Devon Hall, executive director of the Rural Empowerment Association for Community Help, located in Duplin County, North Carolina.