• Filters
  • only
  • only
  • only
  • only
  • only
  • only
  • only
  • only

Select All / Deselect All


Current Challenges in the World of Infectious Diseases

One of our greatest challenges is the continuing global impact of infectious diseases. Infections cause roughly 20% of all human deaths each year.

Pandemics and epidemics have changed the course of history and society, from ancient plagues to HIV/AIDS to cutting-edge biological warfare. The enormous impact of infectious diseases on our world cannot be overstated — and should not be underestimated.

Approximately 1,400 known species of human pathogens exist to wreak this staggering havoc on us, but to put it into perspective, these pathogens account for less than 1% of the total microbial species sharing this planet.


Here are a few of the current global trends that make our relationship with infectious diseases so challenging:

Climate change and vector-borne disease
Warmer weather brings more mosquitoes, and mosquitoes spread pathogens like Zika and Dengue from infected hosts to healthy bystanders. Also, the greater diversity of plants and animals that flourish in a region, the richer variety of pathogens is present there.

Antimicrobial resistance
Bacteria can rapidly evolve and adapt in response to changes in their environment, especially when external influences like antibiotics are overused or inappropriately used. The World Health Organization recently released a priority list of 20 antibiotic-resistant “superbug” pathogens with a plea for scientists to research new treatments for these global threats.

Too much data
Overwhelming amounts of data can accumulate for each patient from multiple sources: biomedical, genomic, clinical, and laboratory/diagnostic. It can be hard to filter the signal from the noise and get a clear picture of the real problem.

Increasing numbers of immunocompromised patients
More patients than ever before are receiving bone marrow transplants, solid organ transplants, chemotherapy, and immunosuppressive treatments. Caring for these patients can be difficult because the list of potential infections is much longer when immune systems are weakened. Existing tests are not always designed to look for less common pathogens.

Emerging threats
Some of the high-impact infectious diseases facing the world today include Zika, Ebola, West Nile, Influenza, food-borne illness, and global pandemics like HIV, TB, and malaria. There are also ongoing threats from neglected tropical diseases and parasites, healthcare-associated infections, and invasive fungal infections, not to mention the continued discovery of new and emerging pathogens.


With challenge comes opportunity. Despite high mortality from infectious diseases, rapidly evolving pathogens, and a dwindling arsenal of treatments that seems to grow less effective with each passing year, human ingenuity has succeeded in developing new, better diagnostic tests and targeted care protocols.

It was only in the late 1800’s that scientists realized microbes could cause specific diseases. Growing bacteria in culture or staining them under a microscope were once the gold standard for diagnosis, and are still commonly used today.

While these methods are still important, newer technologies like PCR and high-throughput genome sequencing enable faster, highly accurate identification. Multiple pathogens can be detected in a single patient, new microbes and genetic variants of known microbes may be discovered, and bioinformatics techniques like phylogenetic comparisons and genome assembly analysis allow for deeper understanding of pathogens to inform potential treatment options.

Next-generation sequencing of DNA fragments circulating in human blood (called cell-free DNA) is another scientific methodology that has been used successfully in other medical fields like prenatal diagnostics, transplant rejection monitoring, and non-invasive diagnosis of cancer. Karius is using specialized and proprietary cell-free DNA sequencing technology for pathogen detection, with the goal of transforming how infectious diseases are diagnosed and monitored. The promise of such genomic technology is that it may promote survival in diseases like cancer or significantly alter the course of a global outbreak.

So how do we tackle the grand challenge of infectious disease diagnosis? We believe the answer is all in the details. Just like an infectious disease specialist would run multiple diagnostic tests while also inquiring in depth about a patient’s symptoms, job, diet, travel, chemical or environmental exposures, and social habits – the more we accurately know, the more we can specifically help. And the faster we find out, the sooner we can have an impact.

Let’s face this opportunity to save human lives together.


  1. Fauci, A. & Morens, D. The Perpetual Challenge of Infectious Diseases. New England Journal of Medicine (2012) 366: 454-461.
  2. Tacconelli et. al. Discovery, research, and development of new antibiotics: the WHO priority list of antibiotic-resistant bacteria and tuberculosis. The Lancet Infectious Diseases (2017). http://dx.doi.org/10.1016/S1473-3099(17)30753-3
  3. Editorial. Microbiology by numbers. Nature Reviews Microbiology (2011) 9: 628.
  4. Fournier et. al. Clinical detection and characterization of bacterial pathogens in the genomics era. Genome Medicine (2014) 6: 114.
  5. Caliendo et. al. Better Tests, Better Care: Improved Diagnostics for Infectious Diseases. Clinical Infectious Diseases (2013) 57: S139–S170.

- Perspective