NIH awards $19 million for new gonorrhea diagnostic test
The National Institutes of Health (NIH) today awarded $19 million for a new diagnostic test that can detect gonorrhea in under 30 minutes—and determine if the infection is susceptible to a single-dose antibiotic. The test is made by Visby Medical, Inc.
The award is part of the NIH's Antimicrobial Resistance Diagnostic Challenge, which aims to improve diagnostics for the more than 2.8 million antibiotic-resistant infections in the United States each year. Those infections kill more than 35,000 people annually, the NIH said in a news release.
"Challenge prizes spur innovation, and we saw many innovative concepts throughout this competition. I want to congratulate Visby Medical for their winning technology, which could help reduce the unnecessary use of antibiotics, a major driver of antimicrobial resistance," said NIH Director Francis S. Collins, MD, PhD.
Visby's device is a palm-sized, disposable test that allows clinicians to treat patients immediately with antibiotics likely to cure their infections.
Gonorrhea, one of the most common sexually transmitted infections in the world, has grown increasingly resistant to antibiotics in recent years. According to the Centers for Disease Control and Prevention, there were more than 580,000 US gonorrhea cases in 2018, a 63% increase from 2014.
Aug 5 NIH press release
Analysis finds Staph bacteremia mortality rises sharply after 2 days
A secondary analysis of patients with Staphylococcus aureus bacteremia suggests that the best cutoff to predict mortality is a duration of 2 days despite active antibiotic therapy, an international team of researchers reported yesterday in The Lancet Infectious Diseases.
In the largest study to date evaluating the risk associated with increasing duration of S aureus bacteremia, researchers with the International Staphylococcus aureus collaboration study group and European Society of Clinical Microbiology and Infectious Diseases Study Group for Bloodstream Infections, Endocarditis and Sepsis assessed outcomes on adults hospitalized for S aureus bacteremia at 17 European hospitals from January 2013 through April 2015. The primary outcome was 90-day mortality. The duration of bacteremia was defined as bacteremic days under active antibiotic therapy, counting the first day as 1.
Of the 1,588 patients assessed for eligibility, 987 were included in the analysis, with a median age of 65 years. Overall, death within 90 days occurred in 273 patients (28%). The 315 patients (32%) with more than 1 day of bacteremia had higher Charlson comorbidity index and sequential organ failure assessment scores and a longer interval from first symptom to first blood culture.
Analysis of the primary outcome found that crude mortality increased from 22% (148 of 672) with 1 day of bacteremia to 39% (85 of 218) with 2 to 4 days, 43% (30 of 69) with 5 to 7 days, and 36% (10 of 28) with more than 7 days of bacteremia. In addition, metastatic infections developed in 6% of patients (39 of 672) with 1 day of bacteremia compared with 13% of patients (40 of 315) who had bacteremia for at least 2 days. The second day of bacteremia had the highest hazard ratio and earliest cutoff significantly associated with mortality (adjusted hazard ratio, 1.93; 95% confidence interval, 1.51 to 2.46; P < 0.0001).
The findings are noteworthy because persistent bacteremia is poorly defined, and applied cutoff durations to define it vary from 2 days to more than 7 days.
"We believe that the second day of bacteraemia after starting active antibiotic therapy represents the most meaningful clinical cutoff to define persistent bacteraemia and to consider the implementation of additional diagnostic and therapeutic measures to reduce the high mortality in S aureus bacteraemia," the authors wrote.
Aug 4 Lancet Infect Dis abstract
Artemisinin resistance mutations detected in Rwandan malaria parasites
Researchers from Rwanda, France, and the United States have detected the emergence and expansion of an indigenous lineage of artemisinin resistant (ART-R) malaria parasites in Rwanda, according to a new study in Nature Medicine.
The researchers conducted an in-depth genetic analysis of Plasmodium falciparum samples collected at six Rwandan sites from 2012 to 2015 and performed gene-editing studies to evaluate the in vitro resistance phenotypes of parasites harboring mutations in the propeller domain of the Pfkelch13 gene, which can mediate artemisinin resistance. Resistance to artemisinin-based combination therapy (ACT) for malaria is widespread in Southeast Asia, particularly in the Greater Mekong Subregion, and has also been identified in Latin America, but to date has not been reported in Africa.
The scientists performed Pfkelch13 propeller domain genotyping on 534 pretreatment samples collected from patients who participated in clinical trials to assess the efficacy of artemether-lumefantrine and dihydroartemisinin-piperaquine for treating uncomplicated P falciparum malaria. While the cure rates in both treatment arms of these trials were above 95%, a Pfkelch13 R561H mutation—previously associated with delayed parasite clearance following ART monotherapy or ACT treatment in the Greater Mekong Subregion—was observed in 19 of 257 samples (7.4%) at the trial site in Masaka.
Gene editing using CRISPR-Cas9 confirmed the Pfkelch13 R561H mutation conferred artemisinin resistance in vitro, and phylogenetic analysis showed a clear separation between the Pfkelch13 R561H mutants found in Rwanda and those found in Southeast Asia and Latin America.
"This study clearly shows the early warning signs of ART-R in Rwanda," the authors wrote. "Genetic analyses indicate that Rwandan Pfkelch13 561H mutants are the product of de novo local emergence."
The authors add that if the spread of ART-R cannot be contained in Rwanda and neighboring countries, a rise in resistance to ACT partner drugs could result, leading to high treatment failure.
Aug 3 Nat Med study