May 2022

Emerging Infectious Diseases Journal

The articles of interest summarized below will appear in the May 2022 issue of Emerging Infectious Diseases, CDC’s monthly peer-reviewed public health journal. This issue will feature viral infections. The articles are embargoed until April 13, 2022, at noon Eastern time.

Important Note: Most articles that EID publishes do not represent work done at CDC or by CDC staff. In your stories, please use our suggested language to clarify whether a study was conducted by CDC (“a CDC study”) or by another institution (“a study published by ____ in the EID journal”). Opinions expressed by authors contributing to EID do not necessarily reflect the opinions of CDC or the institutions with which the authors are affiliated.

Please link directly to the actual journal article in your stories. Once the embargo lifts, this month’s articles will be found in the Early Release section of the EID website.

EID is publishing many articles on the COVID-19 pandemic. Because we publish those articles on an expedited track, and we have no embargo on their content, we do not include them in these monthly press notices. You may wish to subscribe to receive email notifications when EID publishes expedited articles as well as other types of articles.

Note that the most recent EID COVID-19 papers are at the top of the journal’s home page and also included in the Coronavirus Spotlight.

  1. Effects of Tick-Control Interventions on Tick Abundance, Human Encounters with Ticks, and Incidence of Tickborne Diseases in Residential Neighborhoods, New York, Felicia Keesing et al.
    Tickborne diseases, such as Lyme disease, affect nearly half a million people each year in the United States. Tick-control methods have been proven to lower the number of ticks in small areas. To determine whether those methods also lower human exposure to ticks and thus the number of cases of tickborne diseases, researchers analyzed the effects of two environmentally safe tick-control methods: the Tick Control System (baited boxes that attract the small mammal hosts most likely to infect ticks with pathogens) and Met52 (a fungal spray that kills ticks seeking hosts). Researchers used different combinations of tick control on properties of consenting participants living in designated neighborhoods, and asked these participants about time spent outdoors, tick encounters, and tickborne illness. They found that use of Met52 did not lower the number of host-seeking or attached ticks but that the Tick Control System did. The tick-control methods did significantly reduce the incidence of tickborne diseases in outdoor pets, but did not significantly reduced human encounters with ticks or cases of tickborne illness in people. This indicates that reducing the size of tick populations in residential areas might not effectively lower the number of human infections with tickborne diseases.
    Felicia Keesing, Bard College, Annandale, NY; email:; Richard S. Ostfeld, Cary Institute of Ecosystem Studies, Millbrook, NY; email:
  2. Risk for Asymptomatic Household Transmission of Clostridioides difficile Infection Associated with Recently Hospitalized Family Members, Aaron C. Miller et al.
    Clostridioides difficile infection (CDI) is a common cause of severe diarrhea that can result in serious damage to the colon and be fatal. It is one of the most commonly occurring types of healthcare-associated infections and is predominantly associated with hospital stays. More recently, however, reports have become more common for community-associated CDI cases, in which patients without a history of recent hospitalization are infected. To evaluate whether hospitalized patients without diagnosed CDI increased the risk for CDI among their family members after discharge, researchers at the University of Iowa used data from 2001–2017 U.S. insurance claims to compare monthly CDI incidence between people in households with and without a family member hospitalized in the previous 60 days. CDI incidence among insurance enrollees exposed to a recently hospitalized family member was 73% greater than enrollees not exposed, and incidence increased with length of hospitalization among family members. Patients are frequently colonized with C. difficile (meaning they carry the bacteria in their body but are not themselves made sick by it) during hospitalization and when discharged. About 25 million people each year have overnight hospital stays in the United States alone. Asymptomatic C. difficile carriers discharged from hospitals could be a major source of community-associated CDI cases and should be considered by public health authorities during surveillance and intervention-based investigations when a CDI outbreak occurs.
    Contact: Aaron C. Miller, University of Iowa, Iowa City, IA 52242, USA; email:
  3. Usefulness of Domestic Dogs as Sentinels for West Nile Virus but not Aedes-borne Flaviviruses, Mexico, Edward Davila et al.
    Viruses spread by mosquitoes represent substantial health burdens to people across the Americas. One way to track the presence of viruses that can cause human illness is through animals. Some animals don’t get sick from these viruses when bitten by an infected mosquito, but their bodies will still produce detectable antibodies against that virus. These animals can serve as sentinels indicating whether mosquitoes in a given area carry a virus that can make people sick. To determine usefulness of dogs as sentinels for Zika, dengue, and West Nile viruses in Mexico, researchers compared antibody levels in dogs with those of human disease case numbers for the same viruses in the same areas. They found low evidence of dog exposure to Zika and dengue viruses (spread primarily by Aedes aegypti mosquitoes) but high evidence of dog exposure to West Nile virus in northern Mexico (spread by Culex species mosquitoes). This finding suggests that dogs in Mexico are useful as sentinels for West Nile virus but are probably not useful as sentinels for viruses spread by Aedes aegypti, such as Zika and dengue.
    Contact: Gabriel Hamer, Texas A&M University, College Station, TX, USA; email:


Page last reviewed: April 15, 2022