Brain-Eating Amoeba Thrives in Warm, Fresh Water
Sept. 13, 2012 --
The most biologically diverse place on earth is likely Madidi National Park in northwest Bolivia, according to a Wildlife Conservation Society announcement released this week at the IUCN Conservation Congress. Researchers came to the conclusion after compiling a comprehensive list of species found in the remote park. The park contains 11 percent of the world's birds, more than 200 species of mammals, almost 300 types of fish and 12,000 plant varieties. The female black-faced spider monkey seen here is one of at least nine species of primates in the park. "Madidi National Park is simply an outstanding biological reservoir," Robert Wallace, WCS's Madidi landscape program director, told Discovery News.
This butterfly represents just one of more than 1,000 species of butterflies estimated to be in Madidi National Park. Butterflies and moths are often included in climate change studies. Their population numbers and movements can help to reveal certain long-term weather patterns and how they impact biodiversity. Numerous scientists are conducting or planning studies that will provide related monitoring data, Wallace said.
Ornithologists expect that around 1,100 species of birds will be registered within the Bolivian park. This female blue-crowned manakin clearly has a lot of avian company there. Even with such numbers, it's estimated that two-thirds of the park's total biodiversity has yet to be formally registered or observed by scientists, highlighting the need for further research in the region.
Another bird at Madidi is the wattled jacana, one of more than 920 species of birds that have been registered so far at the park. The individual in this photo is a juvenile.
The Palkachupa Cotinga is another avian resident in the park. This individual was snapped while nesting in the dry, mountainous tropical forests and savannas at Madidi. The cloud forests at the park go up to about 9,842 feet, making human access challenging.
The mountainous savannas, cloud forests and Andean peaks take on a dreamy sculptural appearance at dusk.
This view from the Amazonian forest floor shows how lush the plant life is in areas of the park. "The Wildlife Conservation Society is proud to be assisting the Bolivian government in the conservation of these magnificent places," Cristián Samper, president and CEO of the WCS, said. "This important compendium emphasizes just how poorly known the cloud forests of the Tropical Andes really are."
The crested forest toad is one of an estimated 100-plus species of amphibians in the park. Amphibians worldwide have experienced tremendous population drops in recent years, so such a richness of species diversity is extremely rare.
This male jaguar was seen in the late afternoon on the Madidi River. "Apart from the sheer number of species found within the park, I would also like to stress the importance of the park and the surrounding landscape for the conservation of much of the most charismatic of South America's terrestrial wildlife," Wallace said. "WCS has led expert processes that have identified this area as a stronghold for jaguars, white-lipped peccaries and lowland tapirs," he added, "and ongoing and/or recently published research is showing the same for Andean condors, marsh deer, spectacled bears and giant otters."
The parrot snake is one of at least 50 species of snakes in Madidi National Park.
It's no wonder that Madidi National Park is one of the top tourist attractions in Bolivia with views such as this. Here, a 500-plus pound lowland tapir heads to the Madidi River to avoid horse flies. Giant cowbirds followed along to feast on the insects. The park is part of a larger protected region known as the Madidi-Tambopata Landscape, one of the largest such complexes in the world.
Although this individual is just a juvenile, the harpy eagle is the most powerful bird of prey in the world. It thrives at Madidi, thanks to appropriate habitat and ample food sources. WCS has worked in this landscape since 1999 to develop local capacity to conserve the landscape and mitigate a variety of threats. These include development, such as road construction, logging, and agricultural expansion. "Madidi is a very special place and we are honored to be able to continue to show that through these studies, as well as through the accompanying spectacular wildlife photography, and as importantly, provide scientific information with which to assist park authorities and local communities to make appropriate management decisions," Wallace explained.
The brain-eating amoeba that killed a 9-year-old Kansas girl last week is an organism that thrives in warm fresh water and can be found in lakes, rivers, hot springs and soil, according to the Centers for Disease Control and Prevention.
The victim, Hally "Bug" Nicole Yust, reportedly had swum in several lakes over the past few weeks near her home in Spring Hill. The Kansas Department of Health confirmed that she died from primary amoebic meningoencephalitis (PAM) caused by the amoeba, Naegleria fowleri, which she likely inadvertently inhaled via lake water.
"Once forced up the nose, it can travel to the brain, where it digests brain cells," Jonathan Yoder, an epidemiologist at the Centers for Disease Control and Prevention, told Discovery News. "It's a very tragic disease that thankfully is very rare."
Aside from its rarity, the amoeba "is not looking to prey upon human victims," he said. "They usually go after bacteria in water and soil."
As single-celled organisms, amoebas do not even have brains.
However, Naegleria species, including this disease-causing one, can transform themselves into three different basic "body" types.
"This one-celled organism hunts and eats bacteria as an amoeba, swims around looking for a better environment as a flagellate, and then hunkers down and waits for good times as a cyst," said Simon Prochnik, a computational scientist at the U.S. Department of Energy's Joint Genome Institute. "It is a very rare process to go from amoeba to flagellate like this."
Prochnik, who sequenced the genome of a Naegleria species, explained that when environmental conditions are not favorable, the "stressed" amoeba can quickly grow two tails, transforming it into the flagellate. It can then swim and move around to a better spot, similar to the way that human sperm travel.
To support these three body or "personality" types, as Prochnik calls them, the organism is packed with genes: 15,727 of them. To put that into perspective, humans have 23,000 protein-coding genes.
Since the creature is so versatile, it can lurk in warm, moist places for extended periods.
Two Louisiana residents contracted the amoeba a few years ago after using a neti pot, which looks like a teapot and is used for nasal irrigation to relieve sinus problems. The CDC determined that the organism was living in the victims' home water system systems. The individuals apparently did not boil the water before placing it in the neti pots.
Yoder said it is important to follow the directions included with neti pots. The instructions usually mention that users should put distilled, boiled water in them and not just water right out of the tap.
If users don't follow these instructions, there is a slim chance they too might get the disease caused by Naegleria fowleri.
According to CDC data, the fatality rate is over 97 percent. Only three people out of 132 known infected individuals in the United States from 1962 to 2013 have survived.
An image of Trophozoites of N. fowleri in brain tissue, stained.CDC
Diagnosing this disease is difficult. Yoder explained that associated symptoms, such as high fever, headache, and stiff neck, are present with bacterial and viral meningitis, so misdiagnoses are possible.
The Kansas Department of Health and Environment reports, however, that the infection is rare and that Yust was only the second known case of a person contracting the infection in Kansas. The state will likely issue warnings to recreational water users, as other states like Florida have done following similar deaths.
"During the hottest time of the summer, water in ponds, lakes, and rivers become very warm and there can be increases in the amounts of amoeba present," said Florida DOH spokesperson Christie Goss. "We advise everyone to be aware of the danger of swimming in such water, but especially of stirring up the sediment in shallow water or diving and swimming under water which can enable the amoeba to enter the nose and possibly infect the brain."
Both the DOH and the CDC add that it may help to "hold your nose, or use nose plugs when jumping or diving into water."
Health officials at the CDC and elsewhere continue to monitor cases of the disease to detect any possible patterns or if the caseload might rise in future due to climate change or other possible contributing factors.