Cat Poop Spread Parasites

Be careful next time you change the kitty litter — cat poop can carry a nefarious parasite that may be much more widespread than thought, researchers say.
Cats in the United States release about 2.6 billion pounds (1.2 million metric tons) of feces into the environment every year. Cat dung carries the parasite Toxoplasma gondii, a single-celled organism that creates infectious agents called oocysts. These oocysts can infect pregnant women, causing congenital problems in the baby such as deafness, seizures, eye damage and mental retardation. The parasite also infects people with compromised immune systems, such as those with HIV/AIDS.
After reviewing past studies on the parasite, a team of researchers believes the Toxoplasma parasite may be a significant public health problem, infecting people who are otherwise healthy. Other studies have even linked the parasite to schizophrenia, depression, suicidal behavior and lower school achievement in children.
In the last five years, researchers have studied how long the Toxoplasmaoocysts remain viable. "What happens to these oocysts in children's play areas?" said study researcher E. Fuller Torrey, a psychiatrist at Johns Hopkins University Medical Center in Chevy Chase, Md. "I put together the data we have and found it disturbing."
Troubling trend
Torrey and his colleagues reviewed studies of the parasite. The number of cats in the United States is growing — pet cats increased from 55 million to 80 million from 1989 to 2006, and the number of feral cats is estimated at between 25 million and 60 million. Studies show that approximately 1 percent of cats shed the infectious oocysts at any given time. These oocysts can survive for at least 18 months, and only a single one is needed to cause an infection, according to past research.
Other animals, like sheep and cattle, can also acquire the parasite by ingesting the infected cat feces. Humans can acquire it by eating raw or undercooked animals that are infected. In countries like France or Ethiopia, where raw food is common, the incidence of infections is much higher, Torrey told LiveScience. People also become infected through contaminated water supplies. It has long been known that the parasite can survive in cat litter, where the oocysts become aerosolized after 24 to 48 hours, Torrey said. Similarly, children could acquire the infection from playing in sandboxes, and gardeners could acquire it from vegetable patches, because cats often relieve themselves in these areas.
"It's a remarkably complex parasite. It's much more complicated than a virus, and has many more genes," Torrey said. The microbe is famously known to infect rats and change their behavior, causing them to be less afraid of the smell of cat urine. This makes it easier for the rats to be eaten by cats, returning the parasite to its host.
Parasite prevention
Treatments do exist, but none are very effective, Torrey said. Most people don't have long-term effects, but it's not clear why some do. Genetic predisposition or age at the time of infection could play a role, Torrey said.
More research is needed to understand the risks posed by the Toxoplasma parasite.  In the meantime, Torrey advocated controlling cat populations, especially feral ones. Children's sandboxes should be covered. Gardeners should wear gloves and wash their vegetables. And cat owners should dispose of cat litter properly — in the trash, not down a toilet (and pregnant women shouldn't change it at all).
"None of us are saying cats shouldn't be pets," Torrey said, but "there are some downsides to all pets, and some downsides to cats we should be aware of."

Big Lionfish Found

The relentless scourge of lionfish has crept to unexpected depths: Off the coast of Florida, researchers say they found the venomous invader thriving around a sunken ship at 300 feet (91 meters) below the water's surface.
"We expected some populations of lionfish at that depth, but their numbers and size were a surprise," researcher Stephanie Green, of Oregon State University, said in a statement.
Last month, Green and colleagues investigated the seafloor near Fort Lauderdale, Fla., in a deep-diving Antipodes sub. At 300 feet (91 m) deep, the team witnessed a large number of the spiny fish near the intentionally sunken Bill Boyd cargo ship, an artificial reef created in 1986.
While lionfish are typically between 12 and 15 inches (30 to 38 centimeters) long, the Oregon State researchers say they saw unusually large specimens as big as 16 inches (40 cm) long.
"This was kind of an 'Ah hah!' moment," Green said. "It was immediately clear that this is a new frontier in the lionfish crisis, and that something is going to have to be done about it. Seeing it up-close really brought home the nature of the problem."
Native to tropical Indo-Pacific waters, lionfish were introduced to the Atlantic by humans in the 1990s, likely through the exotic pet trade. Now found in reefs from North Carolina to South America, the rapidly reproducing invasive fish have voracious appetites, gobbling up native fish and competing with other species for food resources.
Worse, lionfish have no natural enemies in Atlantic waters, except spear gun-toting humans. Another study, detailed online July 11 in the journal PLOS ONE, found that not even sharks can curb red lionfish populations in Caribbean reefs.
Researchers are trying to figure out what is keeping lionfish in check in the Pacific so that they might stem the Atlantic invasion, which thus far has looked to be unstoppable. Prepared correctly, lionfish are said to make a tasty meal, but one prick from the fish's venomous spine can cause excruciating pain. Lionfish derbies to bring in big catches of the predator have been held in Florida and the Caribbean.
"A lionfish will eat almost any fish smaller than it is," Green said in a statement. "Regarding the large fish we observed in the submersible dives, a real concern is that they could migrate to shallower depths as well and eat many of the fish there. And the control measures we're using at shallower depths — catch them and let people eat them — are not as practical at great depth."
Lionfish also can produce far more offspring when they are large. A big, mature female in some species can have up to 10 times as many offspring as a female that's half its size, researchers say.

First test-tube baby born

The first test-tube baby to come from an embryo screened for genetic defects using a new, low-cost technique that could improve in-vitro fertilization success rates was born last month and is a healthy boy.
The birth in June was announced on Monday as part of a study that scientists said validated the concept of next-generation genome screening, although more clinical tests are needed before the system is used widely.
The new technique uses modern low-cost DNA sequencing to spot both whole chromosome abnormalities and specific gene defects before an embryo is implanted in the womb.
Only around 30 percent of embryos selected during in-vitro fertilization (IVF) - when eggs are fertilized with sperm in a lab dish - actually implant successfully, and chromosomal defects are a major factor in failures.
Other genetic screening methods have been developed over the past decade but the new system should be substantially cheaper, researchers believe.
"We can do this at a cost which is about a half to two-thirds of what current chromosome screening costs are," said Dagan Wells of the University of Oxford.
"If further randomized trials confirm this, we could reach a point where there is a very strong economic argument that this should be offered very widely - perhaps to the majority of IVF patients."
Screening of embryos in IVF is currently reserved for older women, who are at increased risk of chromosomal abnormalities, and those with recurrent miscarriages.
Wells will present his research, which also includes results of laboratory tests on cells with known genetic defects, at the European Society of Human Reproduction and Embryology (ESHRE) annual meeting in London.
A second woman who underwent the screening process is due to give birth shortly.
Stuart Lavery, director of IVF at Hammersmith Hospital in London, who was not involved in the work, said the rapid analysis of vast amounts of DNA using the new genome sequencing technique was "amazing science".
"It gives us a very, very powerful tool for examining pre-implantation genetic diagnosis and gives us increased confidence when looking at multiple genetic abnormalities in a human embryo," he told reporters.
But Lavery added there needed to be a randomized clinical trial program to confirm the efficacy of the approach - something Wells and his team plan to begin later this year.
One in six couples worldwide experience some form of infertility problem at least once in their lifetime, according to ESHRE.