杏吧原创

Diseases transmitted by cats cost the Australian economy more than A$6 billion (拢3.3 billion) annually through their impact on human health and livestock production.

Sarah Legge at Australian National University in Canberra and her colleagues have analysed the economic impact of cat scratch disease, in which a scratch or bite can cause an infection of the bacterium Bartonella henselae, and toxoplasmosis, a parasitic disease.

The researchers estimate that these diseases and others spread by cats to humans cost the Australian economy $6.06 billion annually in medical care, insurance, social support and lost productivity.

Toxoplasmosis also affects animals, causing miscarriages in sheep and goats. Another parasitic disease that spreads through cats, sarcocystosis, causes cysts to form in sheep meat, which reduces the amount that can be sold. The researchers estimate that the two parasitic diseases result in annual costs to livestock production of about $11.7 million.

Toxoplasmosis is a result of an infection with the parasite Toxoplasma gondii, which cats can catch when they prey on infected birds, mice or other small animals. The parasite reproduces inside cats, and the disease probably wouldn鈥檛 exist in Australia if cats hadn鈥檛 been introduced by the British in 1788.

Infected cats release the T. gondii oocysts 鈥� an egg-like form of the parasite 鈥� in their faeces, which people can then accidentally ingest, for example while gardening. People can also ingest the oocysts by eating raw or undercooked meat that is infected.

The parasite enters the body, often the brain, and remains there indefinitely.

The researchers used estimates of toxoplasmosis prevalence 鈥撀燼bout 30 per cent of the global population 鈥� as well as the frequency of聽its health impacts. They combined government and other research statistics on medical costs and employment data.

鈥淭he biggest single contributing cost is from the effects of this parasite on behaviour and mental health,鈥� says Legge.聽Most toxoplasmosis cases are asymptomatic, but even in these cases people have slower reaction times and can show behavioural changes.

Toxoplasmosis is linked to higher rates of traffic accidents and mental illness. However, although the associations are extremely strong, says Legge, it is difficult to prove causation.

To break the cycle of T. gondii聽transmission, efforts should be targeted at reducing feral cat populations and also at keeping pets indoors, says Legge.