Havlíček J., Gašová Z., Smith
A. P. , Zvára K, J. Flegr J.( 2001) Decrease of psychomotor performance in subjects
with latent "asymptomatic" toxoplasmosis. Parasitology, 122, 515-520.
Keywords:
manipulation hypothesis, parasite, human, reaction times, Toxoplasma gondii, behaviour,
evolution
RATTUS-NORVEGICUS, GONDII, INFECTION, MICE, BEHAVIOR, NOVELTY, SERIES, MOUSE,
AIDS, WILD
Abstract:
Toxoplasma gondii is known to induce specific behavioural changes in its intermediate
hosts. This is usually considered to be an evolutionary adaptation aimed to increase
the probability of transmission of the parasite into its definitive host, the
cat, by predation. In rodents an increase of reaction time as well as many other
specific behavioural patterns have been observed. Here we report the results of
our double blind study showing the significantly longer reaction times of 60 subjects
with latent toxoplasmosis in comparison with those of 56 controls. Moreover, the
existence of a positive correlation between length of infection and mean reaction
time suggested that slow and cumulative effects of latent toxoplasmosis rather
than a one-step (and possibly transient) effect of acute toxoplasmosis disease
are responsible for the decrease of psychomotor performance of infected subjects.
To our knowledge, this is the first study confirming the existence of such parasite-induced
changes in human behaviour that could be considered in evolutionary history of
the human species as adaptive from the point of view of parasite transmission.
ISSN 0031-1820
IF 1,944
UK