Top Infectious Disease News of the Week—July 15, 2018

#5: Citizen Science Research Demonstrates Value in Identifying Tick Prevalence in the US

A citizen science sampling study published in PLoS One highlights the value of citizen participation in research, particularly in regard to identifying tick prevalence in North America.

Using citizen participation data collected from 49 states, researchers from Northern Arizona University (NAU) found that tick exposure is highest during the spring months, with Ixodes scapularis, Dermacentor variabilis, and Amblyomma americanum representing the most prevalent tick species affecting individuals in the United States. Additionally, researchers found that human hosts are the most common host types, with many of these hosts more often bitten by adult ticks.

"Utilizing citizen science could be a broadly efficient way of filling a large gap that currently exists in our understanding of tick-borne disease risk,” Nathan C. Nieto, PhD, of NAU, explained in a recent statement. “This study offers a unique perspective, as it looks at risk to humans that goes beyond the physician-reported infection rates and involved ticks that were found on or near people.”

Read more about using citizen science research to identify tick prevalence.

#4: Vibriosis Cases Prompt Calls for Summer Water Activity Safety

The summer months are a time for water activities, but with these activities, there can be a risk for water-borne diseases. Following several cases of vibriosis around the country, health officials are urging the public to practice water safety.

Vibriosis is an intestinal or skin infection caused by Vibrio bacteria, which naturally occur in coastal waters particularly in the warmer months ranging from May to October. The Centers for Disease Control and Prevention (CDC), estimates that there are 80,000 vibriosis illnesses in the United States each year, resulting in about 100 deaths. Anyone can become exposed to the bacteria by eating seafood, such as raw oysters, raised in waters containing one of the dozen Vibrio species that cause human illness. Exposing open wounds to seawater or seafood contaminated can also cause vibriosis. Ingesting seafood contaminated with Vibrio can lead to diarrhea, nausea, abdominal cramping, fever, and chills, with symptoms lasting up to 3 days.

Read more about vibriosis.

#3: Infected Mice Found in Pressed Grapes Leads to Oropharyngeal Tularemia Outbreak

A small outbreak of oropharyngeal tularemia that occurred in grape harvesters at a German vineyard in October 2016 has been linked with the consumption of pressed grapes contaminated with wood mice DNA.

The retrospective study findings made by a team of German researchers have been published in the New England Journal of Medicine.

Antibodies to Francisella tularensis lipopolysaccharide, the bacterium that causes tularemia, were detected in 6 of 29 harvesters at the vineyard and was confirmed on Western blot analysis, following complaints of swollen cervical lymph nodes, fever, chills, difficulty swallowing, and diarrhea, within 4 to 8 days after the suspected exposure.

Tularemia is a disease for which rabbits, hare, and rodents are susceptible, but human infections are possible and can occur through insect bites, skin contact with infected animals, inhalation of airborne bacteria, or consumption of contaminated food and water, according to the Centers for Disease Control and Prevention (CDC).

Read more about the tularemia outbreak.

#2: Salmonella Outbreak Tied to Pasta Salad Springs Up in 5 States

The US Centers for Disease Control and Prevention (CDC) and US Food and Drug Administration (FDA) are working alongside state health officials to investigate another multistate outbreak of Salmonella infections, which have, this time, been tied to Spring Pasta Salad.

Salmonella outbreaks have been popping up all over the United States this summer with multistate outbreaks linked with Kellogg’s Honey Smacks and Pre-Cut Melon announced in June.

As of July 17, 2018, 21 cases of Salmonella Sandiego have been reported across 5 states. Five of the 21 individuals have required hospitalization for their illnesses; however, and no deaths have been reported so far, according to the CDC.

Read more about the Salmonella outbreak.

For the most recent case counts associated with the Salmonella pasta salad outbreak, be sure to visit the Contagion^® Outbreak Monitor.

#1: FDA Approves the First Complete Darunavir-Based Single-Tablet Regimen for HIV

The US Food and Drug Administration (FDA) has approved the first and only complete, darunavir-based single-tablet regimen (STR) for the treatment of HIV in treatment-naïve and certain virologically suppressed adults. The drug, D/C/F/TAF (SYMTUZA), which has been developed by the Janssen Pharmaceutical Companies of Johnson & Johnson, combines the resistance of darunavir with the tolerability and convenience of an STR.

"As clinicians, we may not always have the full picture of a patient's health or their risk for developing resistance when making treatment decisions,” Joseph Eron, MD, professor of medicine, Director, Clinical Core, University of North Carolina Center for AIDS Research said in the announcement, “In key Phase 3 clinical trials, SYMTUZA successfully treated those who were starting therapy, as well as those who were stably suppressed on antiretroviral (ARV) therapy — including patients with more complex treatment histories or previous virologic failure – demonstrating its potential as an important new treatment option for a wide variety of patients."

The FDA based the approval on data from 2 phase 3 studies, AMBER and EMERALD that assessed the safety and efficacy of D/C/F/TAF compared with a control regimen in adult patients without prior antiretroviral therapy and in virologically suppressed adults, respectively.

In the AMBER trial, the drug was compared with darunavir/cobicistat plus emtricitabine/tenofovir disoproxil fumarate. Results demonstrated similar suppression rates between the darunavir-based STR and the control (91.4% vs 88.4%) and low virologic failure rates (HIV-1 RNA ≥50 c/mL; 4.4% vs. 3.3%) at 48 weeks. Overall, the drug was well tolerated with few discontinuations due to an adverse event (2% vs. 4%) versus control; only 1 grade 3 adverse reaction occurred, and there were no grade 4 adverse reactions reported. Adverse reactions reported in ≥2% of subjects included diarrhea, rash, nausea, fatigue, headache, abdominal discomfort, and flatulence.

Read more about the first complete darunavir-based single-tablet regimen.