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Weekly Digest: New Data on CDDEP’s ResistanceMap; Extensively drug resistant (XDR) typhoid outbreak in Pakistan

Weekly Digest: New Data on CDDEP’s ResistanceMap; Extensively drug resistant (XDR) typhoid outbreak in Pakistan

New Data on CDDEP’s ResistanceMap.  This week, CDDEP researchers added data from several new countries to ResistanceMap, the largest, most comprehensive repository of country-level resistance data. The newly added countries include: Bahrain, Egypt, Georgia, Korea Rep., Lebanon, Malawi, Tunisia, Zambia, and Zimbabwe. CDDEP researchers also added more current data for India, the Philippines, Vietnam, and the United States. In addition, estimates for antimicrobial use in animals were updated to reflect recent analyses by CDDEP researcher Thom van Boeckel. Currently, ResistanceMap has data on resistance for 66 countries around the world.  To view a map of the countries with available data, go to https://resistancemap.cddep.org.

Extensively drug resistant (XDR) typhoid outbreak in Pakistan. A recent report in mBio investigating the ongoing typhoid outbreak in Pakistan found over 300 isolates of Salmonella Typhi clones harboring resistance to three first-line drugs (chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole) as well as fluoroquinolones and third-generation cephalosporins. Using whole genome sequencing, the researchers found that these extensively drug resistant (XDR) S. Typhi clones harbored a promiscuous antibiotic resistance plasmid previously identified in other Gram-negative enteric bacteria, highlighting the rapidity at which previously treatable infections can rapidly become untreatable. In addition to the XDR clones identified in Pakistan, a case of travel-associated XDR typhoid was also identified, demonstrating how quickly resistance can spread globally. [Report]

Doctors who prescribe antibiotics in poor countries lack local resistance data.  Researchers from the London School of Hygiene and Tropical Medicine interviewed 246 healthcare professionals in six low-income countries on their awareness of antimicrobial resistance (AMR) and knowledge of antibiotics and its impact on prescribing. Although the healthcare professionals had a higher than expected level of knowledge about antibiotics and AMR, their prescribing practices were influenced more broadly by the high cost and limited availability of antibiotics, particularly second-line therapies, and concerns about burden of disease. Patterns of AMR did influence their empirical decision-making, but notably, their knowledge of AMR was due more to treatment failure than to diagnostics. [Report]

Higher rates of MRSA-related hospitalizations in the South. CDDEP researchers, analyzing national hospitalization data for the United States, found that rates of MRSA were higher in the Southern part of the country. Using seasonal trends in the hospitalization rate, the researchers found that seasonal increases in MRSA-related hospitalizations were much higher in the South. As the South is generally warmer, they suggest that warmer weather likely plays an important role in driving rates of MRSA higher in the South. In addition, the authors suggest that antibiotic prescribing is significantly higher in Southern states and likely contributes to higher rates of MRSA in this region as well. [Clinical Infectious Diseases]

Bringing back blue dye to block malaria transmission. Methylene blue, a popular name for methylthioninium chloride, was once considered for stopping transmission of malaria, but was not used because of an undesired side effect—blue urine. The chemical is now being reexamined and evaluated as a potentially important tool to prevent the spread of Plasmodium falciparum from infected individuals to mosquitoes. In a single-blind type 2 trial, researchers in Mali found that the addition of methylene blue to a standard combination antimalarial regimen resulted in faster and more complete clearance of Plasmodium falciparum gametocytes, the stage of the parasite’s life cycle during which the parasite can be transmitted from an infected human to a mosquito. [Healio Infectious Disease in the NewsNational Public RadioLancet Safety articleLancet Comment]

Patients in low income countries more likely to get resistant post-surgical infections. An international study of post-surgical infections found that twelve percent of patients undergoing gastrointestinal surgery developed an infection. Results varied widely across countries, with only nine percent of patients in high income countries developing an infection, compared to twenty-three percent of patients in low income countries. The proportion of infections found to be resistant to antibiotics also varied widely, from seventeen percent in high income countries to thirty-six percent in low income countries. Results also showed that availability of a safety checklist was not directly related to “cleaner” results.  Lancet commentators postulate that “cultural willingness to follow established, local protocols for infection prevention” is more important than simply having access to a checklist. [Lancet; Lancet Commentary; Medical Xpress; Telegraph]

 In Australia, an alarming increase in treatment-resistant gonorrhea. The latest April-through-September Critical Antimicrobial Resistance (CAR) Alert has revealed that cases of multi drug resistant gonorrhea increased almost threefold to 342 cases, compared to the same time period in 2016.  Recently published data from the Melbourne Sexual Health Centre (MSHC) in the state of Victoria showed that cases of gonorrhea—including resistant strains—diagnosed in its clinics reached 1,719 in 2016, which represents an increase of approximately 30% per year since 2010.  Nearly 80 million people worldwide are diagnosed with gonorrhea. [Report; Australian Journal of Pharmacy; News.com.au]

Changes in fecal biome of broiler chickens. Using metagenomic analysis, scientists analyzed the effects of two different antibiotic regimens, low- and therapeutic-dose levels of chlortetracycline, to characterize resulting changes in the microbiome of chicken feces.  Researchers discovered alterations in the microbial community that were dependent on the specific subtypes of antibiotic resistant genes (ARGs) rather than the overall ARG level. These findings reinforce prior studies by CDDEP researchers which highlighted the serious global consequences of over-using antibiotics in meat production.  CDDEP’s September  2017 article in Science recommended three interventions to reduce antibiotic use globally: capping the use of antibiotics in farm animals, reducing meat intake, and charging a 50% user fee on veterinary antibiotics. [Microbiome Journal]

Childhood diarrheal disease has major impacts even when children survive. The consequences of childhood diarrheal episodes include undernutrition, growth faltering, impaired cognitive development, and increased risk of infectious disease, which can contribute to lifelong disability and reduced income potential for individuals, families, and nations.  Researchers calculated that the global burden of diarrheal illness is 39% higher when long-term effects are added to conventionally calculated estimates. [Lancet Article; Lancet Commentary]

End-of-life use of antibiotics has implications for antimicrobial stewardship programs (ASPs).  A study of physicians caring for patients at the end of life shows that numerous factors influence their treatment plans.  Institutional culture, desire to respect patient or family decisions, and belief in treatment effectiveness may lead doctors to continue or discontinue antibiotic treatment, and these factors differ for pediatric versus adult patients. [Infection Control and Hospital Epidemiology, CIDRAP]