- LONDON (ANI) -- Research
on diseases spread by pets has come up with alarming results. According
to a recent study, the domestic cat has spread a parasite that causes devastating
birth defects in humans.
- More than a quarter of the world's population is now
infected with toxoplasma gondii, a relative of the malaria bug, the study
conducted by an Anglo-American team and reported in The Telegraph said.
- Infected people with weakened immunity often develop
acute toxoplasmosis, which can lead to birth defects, brain inflammation
and vision problems.
- It has also been suggested that the parasite, which invades
the brain, may influence behaviour and trigger schizophrenia.
- Although it can sexually reproduce only in cats, the
creature mutated so it could asexually reproduce in a vast range of warm-blooded
hosts, including humans.
- Dr David Sibley and colleagues at Washington University,
St Louis, Cambridge University and the University of Georgia claim that
the three main strains of the toxoplasma arise from a single mating about
10,000 years ago.
- This allowed these parasites to abstain from sex and
made being eaten an attractive option, so they could easily invade any
- The timing of the rise of this asexual form is significant,
said Dr Jim Ajioka, of Cambridge University. As the more infectious bug
emerged, agriculture developed and animals such as cats were domesticated.
- Until recently, scientists had thought that the parasite
was usually harmless, a cause for concern only to pregnant women and people
with a weakened immune system, such as AIDS and transplant patients.
- Then a team at Oxford University found that rats and
mice behaved more recklessly when infected. Dr Jaroslav Flegr and colleagues
at Charles University in Prague concluded that the reaction times of infected
mice were slower.
- "This makes them more vulnerable to a feline pounce,
which is exactly what the parasite wants," Dr Flegr was quoted as
saying in the report.
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