Top Infectious Disease News of the Week May 5, 2019

#5: Study Finds 32 Predictors of C Diff Infection Recurrence

Nearly 1 out of 5 patients with Clostridium difficile infections (CDI) progress to have 1 or more recurring infections, often within a month of treatment, but now a new study has identified predictors for recurrence.

“Following the first recurrence, the risk of an additional episode of CDI increases to between 45% and 65%,” note the study’s authors. “Recurrent CDI is challenging to treat and causes significant morbidity, mortality, and reductions in quality of life. Identifying those at highest risk for recurrence could allow for targeted initial CDI management and may improve patient outcomes.”

For the research, published in the American Journal of Health-System Pharmacy, investigators conducted a matched case-control study among patients in the veteran population treated for their first CDI episode in Veterans Affairs facilities across the United States from May 1, 2010 to December 30, 2014. Study investigators defined first recurrence as a subsequent CDI episode at least 14 days after the positive stool test date and within 30 days of the end of treatment of the initial CDI occurrence, noting that previous research has found that the risk for recurrence is highest 10 days after treatment completion.

Read about predictors of C Diff infection.

#4: Antibiotic Prescribing Varies Greatly Among Family Physicians in Canada

Antibiotic prescribing varies greatly among family physicians, and the differences aren’t explained by patient characterizations, according to a recent study in Canada.

The 5-year cohort study, published in the Journal of Antimicrobial Chemotherapy, examined nearly 4 million patient visits involving more than 300,000 patients and more than 300 family physicians.

The study found a median of 54 antibiotics prescribed per 1000 visits, with female patients between the ages of 3 and 5 being the most likely to receive antibiotics compared with men aged 65 and older, according to the study.

“The biggest surprise was that patient characteristics explained none of the interphysician variability,” corresponding author Kevin Schwartz, MD, MSc, FRCPC, DTM&H, told Contagion^®. “We found that after adjusting for all patient characteristics the odds of a patient receiving an antibiotic, on average, varied by 1.7 times simply by virtue of the physician they saw. This is a remarkable amount of variation that seems to be completely driven by the physician themselves and not the type of patients that they see.”

Read about the variation in prescribing.

#3: Mystery E coli Outbreak Likely Linked to Ground Beef

In early April, the US Centers for Disease Control and Prevention (CDC), announced an investigation into a multistate outbreak of Shiga toxin-producing E coli O103. When the outbreak was announced, there were 72 linked cases across 5 states, yet health officials were unable to pinpoint a common source of infection.

On April 12, 2019, the CDC released an update on the outbreak investigation, announcing that preliminary epidemiologic information suggested that ground beef could be the common source of infection. Health officials arrived at this conclusion after interviewing some of the ill individuals about the foods they ate in the week leading up to the onset of symptoms. In total, 75 individuals were interviewed and 63 of the ill (84%) reported eating ground beef.

The people reported buying and/or eating ground beef products from several different stores and restaurants. Yet, traceback investigation was still unable to identify a common supplier, distributor, or brand of beef that was a common source of the infection.

Read about the E coli Outbreak.

#2: Candida and C Diff: Rise in Coinfections Could Be the Next Big Health Care-Associated Concern

Coinfection with Clostridium difficile (C diff) and Candida species represents an intersection of 2 of the most concerning health care-associated infections, and now a new paper by investigators in Italy explores these coinciding bacterial and fungal infections.

A 2017 survey found that nearly 10% of Americans hospitalized for candidemia—a fungal infection of the bloodstream—were coinfected with C diff, a bacterium which causes nearly half a million intestinal infections in the United States each year. According to the US Centers for Disease Control and Prevention (CDC), there are about 25,000 cases of candidemia in the US each year. A review paper published in the journal Expert Review of Anti-infective Therapy analyzes the physio-pathological mechanisms underlying the Candida and C diff coinfection, as well as its management, including in cases where candidemia occurs both before and following C diff infection (CDI).

In the new paper, investigators from the University of Pisa and Sapienza University of Rome note that, since the first-reported association between CDI and subsequent candidemia in 2013, newer research has identified Candida-C diff coinfection as a clinical entity. “The sharing of similar risk factors partially explains this mutual association. However, the observation that the sequence CDI-candidemia is more frequent than candidemia-CDI led scientific community to research a specific pathophysiological explanation of this finding,” the investigators write. “The alteration in the gut microbiome and the loss of intestinal barrier are the crucial processes favoring the development of candidemia in patients with CDI.”

Read about the rise in Candida and C Diff Coinfections.

#1: Health Officials Confirm Presence of "Kissing Bug" in Delaware

A recent article published in the US Centers for Disease Control and Prevention’s (CDC) Morbidity and Mortality Weekly Report details the first detection of a Triatoma sanguisuga, an insect also nicknamed a “kissing bug,” in Delaware.

Triatomines are a type of blood-sucking insect that feeds on humans and animals and is known for biting the face of humans. These vectors can transmit the parasite Trypanosoma cruzi, which causes Chagas disease, a serious infection that can lead to serious cardiac and gastrointestinal complications.

Triatomine insects are more commonly encountered in Latin America, although they have been previously detected in the United States. The CDC estimates that approximately 300,000 individuals in the United States are living with Chagas disease, yet very few of these cases are connected with contact with the bug within the United States.

According to the CDC, the case in Delaware was reported by a family living in Kent County who requested assistance from the Delaware Division of Public Health (DPH) and Delaware Department of Agriculture (DDA) in identifying an insect that had bitten their child’s face as she watched television in her bedroom in July 2018.

The family, who were concerned about vector-borne disease transmission, reported no recent travel, and resided in a home near a heavily wooded area. The report identifies that a window air conditioning unit was located within the bedroom where the child was reportedly bitten.

Health officials with the DDA preliminarily identified the insect as a Triatoma sanguisuga. An image of the insect was sent by the health officials to Texas A&M University, which is home to the Kissing Bug Citizen Science Program, a research organization that documents and collects kissing bugs from across the United States. The program used the picture to confirm the identity of the insect as a Triatoma sanguisuga.

Following the program’s confirmation, the insect was sent to the CDC for morphological species-level identification. Through the use of polymerase chain reaction testing, the CDC found that the insect did not possess T cruzi. An additional bloodmeal analysis detected human bloodmeal, likely from the girl who was bitten in Delaware. According to the report, the girl did not experience any adverse effects.

Read about the presence of the kissing bug in Delaware.