Sleeping sickness is a circadian disorder

Nat Commun. 2018 Jan 4;9(1):62. doi: 10.1038/s41467-017-02484-2.


Sleeping sickness is a fatal disease caused by Trypanosoma brucei, a unicellular parasite that lives in the bloodstream and interstitial spaces of peripheral tissues and the brain. Patients have altered sleep/wake cycles, body temperature, and endocrine profiles, but the underlying causes are unknown. Here, we show that the robust circadian rhythms of mice become phase advanced upon infection, with abnormal activity occurring during the rest phase. This advanced phase is caused by shortening of the circadian period both at the behavioral level as well as at the tissue and cell level. Period shortening is T. brucei specific and independent of the host immune response, as co-culturing parasites with explants or fibroblasts also shortens the clock period, whereas malaria infection does not. We propose that T. brucei causes an advanced circadian rhythm disorder, previously associated only with mutations in clock genes, which leads to changes in the timing of sleep.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Temperature / physiology
  • Circadian Rhythm / physiology
  • Fibroblasts / metabolism
  • Fibroblasts / parasitology
  • Gene Expression
  • Host-Parasite Interactions
  • Humans
  • Male
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Period Circadian Proteins / genetics
  • Sleep / physiology*
  • Sleep Disorders, Circadian Rhythm / complications
  • Sleep Disorders, Circadian Rhythm / physiopathology*
  • Time Factors
  • Trypanosoma brucei brucei / physiology*
  • Trypanosomiasis, African / complications
  • Trypanosomiasis, African / parasitology*


  • Period Circadian Proteins