Toxoplasma It is perhaps the most successful parasite in the world today. This microscopic creature is capable of infecting any mammal or bird, and infecting people on all continents.
Once infected, the person carries Toxoplasma for life. So far, we do not have a drug that can eliminate the parasite from the body. There is no vaccine approved for use in humans.
Worldwide, it is estimated that 30-50 percent of people are infected Toxoplasma Infections may be increasing in Australia. A survey of studies conducted at blood banks and pregnancy clinics across the country in the 1970s showed an infection rate of 30 percent.
However, a recent community study in Western Australia found that 66 percent of people are infected.
The disease caused by this parasite can scar the back of the eye. Our new research looked for signs of disease in healthy people and found that a large number have the sign of Toxoplasma.
We don’t just get it from cats
The cat is the primary host of Toxoplasma.
Cats acquire the parasite when they eat infected prey. Then, for two weeks, they pass large numbers of parasites in their feces in a form that can survive for long periods in the environment, even during inclement weather.
When livestock ingest the droppings while grazing, the parasites settle in the muscles and live there after the animals are slaughtered for meat. Humans can become infected by eating this meat, or by eating fresh produce or drinking water contaminated by cats.
A woman who is infected for the first time during pregnancy can also pass the infection to her unborn child.
while injury Toxoplasma It is very prevalent, and the most important health statistic is the rate of disease caused by infection, which is called toxoplasmosis.
How does it affect the eye?
Toxoplasma He really likes the retina, the multi-layered nervous tissue that lines the eye and generates vision. The infection can cause recurrent episodes of retinitis and permanent scarring of the retina. This is known as ocular toxoplasmosis.
Contrary to much of what is written about ocular toxoplasmosis, medical research shows that this condition usually affects healthy adults. However, in the elderly or people with weakened immune systems, or when infected during pregnancy, it can be more severe.
An attack of active inflammation causes “floaters” and blurred vision. When the inflammation progresses to scarring, there may be permanent vision loss.
In a study of ocular toxoplasmosis patients in a large ophthalmological clinic, we measured vision decline below the driving level in more than 50 percent of eyes, and 25 percent of eyes that were irreversibly blind.
How many eyes?
Ophthalmologists and optometrists are well versed in the management of ocular toxoplasmosis. But the scale of the problem is not widely recognized, even by the medical community. The number of Australians infected with ocular toxoplasmosis has not yet been measured.
We wanted to investigate the prevalence of ocular toxoplasmosis in Australia, but we knew it would be difficult to obtain funding for a large survey of this neglected disease.
Therefore, we used the information collected for a different purpose: As part of the Busselton Study of Healthy Aging, retinal images were taken from more than 5,000 neonates (born 1946-1964) living in Busselton, Western Australia.
The images were collected to look for other eye diseases, macular degeneration, and glaucoma.
By examining these retinal images, we estimated the prevalence of ocular toxoplasmosis in one in 150 Australians. This may sound surprisingly common, but it fits with the way people hold Toxoplasma.
In addition to domestic cats, Australia has large numbers of feral cats. Australia is home to a lot of agricultural land, including more than 50 percent of the global organic farming area.
Most importantly, many Australians like to eat red meat infrequently, which puts them in real danger.
How is the condition treated?
To diagnose ocular toxoplasmosis, it is necessary to perform an examination of the retina, ideally with dilated pupils.
The retinal lesion is easy to detect because of the way Toxoplasma It activates retinal cells to produce certain proteins, and an ophthalmologist or optometrist can immediately recognize the appearance. A blood test is often also done to make the diagnosis.
If the condition is mild, the doctor may allow the body’s immune system to control the problem, which takes a few months. However, a combination of anti-inflammatory and anti-parasitic medications is usually prescribed.
stop the spread
Toxoplasma The infection is not curable, but it can be prevented. Meat sold in Australian supermarkets may be a shelter Toxoplasma. Cooking meat to an internal temperature of 66 ℃ or freezing it before cooking are ways to kill the parasite.
Fresh fruits and vegetables should be washed before eating, and untreated water (such as water from rivers or streams) should be avoided. Gloves should be worn when changing cat litter and hands should be washed afterwards.
The World Health Organization and other international and national health bodies are promoting an approach called One Health to diseases transmitted by humans, animals, and their environments. This includes different sectors working together to promote good health.
Now we know how common ocular toxoplasmosis is in Australia, and there is a real justification for harnessing One Health to combat Toxoplasma infection in this country.
Justin R. Smith, professor of eye health and vision, Flinders University, and Joao M. Furtado, assistant professor of ophthalmology, University of São Paulo.
This article has been republished from The Conversation under a Creative Commons license. Read the original article.