Chemical signal for locust swarming identified in step toward curbing plagues

By Will Dunham

WASHINGTON (Reuters) – Scientists have identified a chemical compound released by locusts that causes them to swarm, opening the door to possible new ways to prevent these insects from devouring crops vital to human sustenance as they have for millennia.

Researchers said on Wednesday they identified the pheromone – a chemical produced by an animal that affects the behavior of others of its own species – in the world’s most widespread locust species, the migratory locust, or Locusta migratoria.

Called 4-vinylanisole (4VA), it is primarily released from the hind legs and is detected by the antennae of other locusts and sensed by odorant receptors, the researchers said.

4VA powerfully attracted locusts regardless of age or sex, the research published in the journal Nature showed. Its production was triggered in the insects when as few as four to five solitary locusts came together, precipitating swarming behavior.

“In human history, locust plagues, drought and flood were considered as three major natural disasters which caused serious agricultural and economic losses all over the world,” said research leader Le Kang, a professor of entomology and ecology at the Chinese Academy of Sciences’ Institute of Zoology.

“As the most widely distributed and one of the most dangerous locust species, the migratory locust represents a serious threat to agriculture worldwide,” Kang added.

Swarms can include billions of locusts and span hundreds of square miles (km) as the insects voraciously consume crops, imperiling food security. Migratory locusts inhabit Asia, Africa, Australia and New Zealand, attacking pastures and critical crops such as wheat, rice, corn, millet, barley, oats, sugarcane and sorghum.

Kang said further research is needed on whether 4VA exists in other locust species such as the desert locust, called Schistocerca gregaria, that currently is ravaging parts of Africa and the Middle East.

The chemical insecticides currently used to suppress locust outbreaks raise concerns about human health and safety. The identification of 4VA could inspire new methods.

A chemical could be developed to block 4VA’s effects to prevent swarming, Kang said, or a synthetic version could lure locusts into traps to be killed. Locusts genetically modified not to respond to 4VA could be developed and released to establish wild non-swarming populations, “subject to biosecurity evaluation,” Kang added.

(Reporting by Will Dunham; Editing by Sandra Maler)

Deadly plague breaks out on Uganda-Congo border, WHO says

FILE PHOTO: A logo is pictured on the World Health Organization (WHO) headquarters in Geneva, Switzerland, November 22, 2017. REUTERS/Denis Balibouse

GENEVA (Reuters) – A deadly form of plague has broken out on Uganda’s border with Democratic Republic of Congo and several people are thought to have died of the disease, the World Health Organization said on Monday.

The agency praised Ugandan health workers for vigilance and prompt action in spotting a suspected outbreak of pneumonic plague, which the WHO says is usually fatal unless detected early and treated with antibiotics.

Uganda’s Health Ministry reported two probable cases of the illness in Zombo district on March 5 after a 35-year-old woman died and her 23-year-old cousin reported similar symptoms, the WHO said in a report.

Further investigation revealed the dead woman had lived in Atungulei village in Congo’s Ituri province, and her 4-year-old child had died days beforehand. Finding her sick at her child’s burial, her relatives took her to Uganda for treatment.

The cousin’s symptoms raised suspicions of plague and a preliminary rapid diagnostic test was positive for the disease. Results on additional specimens sent to Uganda’s Plague Laboratory in Arua were pending. The patient was steadily improving, the WHO report said.

Some 55 people, including 11 healthworkers and people who took part in the dead woman’s funeral, had been identified as high risk contacts and were being followed up.

Three other people reportedly died of similar symptoms in Congo, the WHO said, and Congolese authorities were investigating.

Plague is endemic in Democratic Republic of Congo, Madagascar and Peru, according to the WHO.

Congolese health authorities are already fighting a major outbreak of Ebola further south in Ituri and North Kivu provinces.

Pneumonic plague is caused by the Yersinia pestis bacteria, usually found in small mammals and their fleas. Humans can be infected through flea bites, unprotected contact with bodily fluids or contaminated materials and the inhalation of droplets or small particles from a patient with pneumonic plague.

(Reporting by Tom Miles; Editing by Frances Kerry)

Plague in Madagascar Surprises and Alarms World Health organizations, U.S. not immune

World Health Organization responding to Seychelles plague

By Kami Klein

Experts are alarmed at a recent outbreak of plague that is spreading through major populated areas in Madagascar.  So far there has been 1,836 suspected or confirmed cases of pneumonic plague and 133 deaths in areas that have never seen this form of the disease before.

Every year Africa and Madagascar deal with an outbreak of plague within their borders. The World Health Organization (WHO) anticipates this in outlying areas and is ready to step in with antibiotics and information which eventually curtails the outbreak.  This year, health organizations around the world were surprised as the plague has spread so quickly and is primarily being found in heavily populated areas. While they anticipate around 400 cases a year, this year’s outbreak began sooner and a different strain of the disease has the world watching.

What is causing the alarm is that 65% of the plague occurring in Madagascar, pneumonic plague, is the only form that can be spread from human to human through droplets from coughing.  This makes containing the disease much more difficult and the chances that there will be more deaths almost certain.

According to the Center for Disease Control here in the United States, there are major differences in bubonic plague and pneumonic. Bubonic plague is spread to humans by the bites of infected fleas that live on small mammals such as rats.Without treatment, it kills up to two-thirds of those infected. One in 10 cases will develop into pneumonic plague which is almost always fatal if not treated quickly with antibiotics. This form, can and will spread from human to human which is the case in this outbreak. The good news is that a simple short course of antibiotics can cure the plague, providing it is given early.

Dr. Tim Jagatic told BBC News that the outbreak had spread to populated areas when a man infected with bubonic plague had traveled from the highlands to the capital and then on to the coastal city of Tamatave by bus.

“He had the bubonic form of the plague and entered into one of the major cities, where the bubonic version of the disease had the potential of turning into the pneumonic form without treatment.”

“He was in a closed environment with many people when he started to develop severe symptoms, and he started to transmit the pneumonic form of the disease to others.”

“So it wasn’t recognised until later,” he said, allowing the disease to “proliferate over a period of time unabated”.

This  case infected 31 other people, according to the WHO, four of whom died. It wasn’t until a couple of weeks later that an outbreak of the plague was detected and officially confirmed.

Although a travel ban has not been issued as of yet, officials do expect another spike in the disease before the season ends in April.  Medical personnel are all on  alert in parts of Africa that are most frequented by Madagascar citizens. WHO has delivered nearly 1.2 million doses of antibiotics and released $1.5 million dollars in emergency funds to fight the plague in Madagascar.

Though not widely publicized, the United States does have several cases of plague per year mostly in the Southwest. Dr Tim Jagatic, a doctor with Doctors without Borders currently working in Madagascar stated that the conditions which cause the plague outbreaks on the African island are also found in the US.

“Something today that very few people are aware of is that in the United States for instance, in the south-west, there’s an average of 11 cases of bubonic plague per year.

“These outbreaks occur simply because this is a bacteria which is able to maintain a reservoir in wild animals and every once in awhile, when humans come into contact with fleas that have had contact with the wild animals, it is able to transmit to humans.”

Information Sheet on the Plague

Information Sheet on the Plague


Sources:   BBC, WHO,CDC, New York Post  CNN

Plague outbreak in Madagascar kills 20: WHO

NAIROBI (Reuters) – An outbreak of plague has killed 20 people in the space of a month in Madagascar, with a further 84 infected, the World Health Organisation (WHO) said on Friday.

Plague is mainly spread by flea-carrying rats. Humans bitten by an infected flea usually develop a bubonic form of plague, which swells lymph nodes and can be treated with antibiotics.

But the more dangerous pneumonic form invades the lungs and can kill a person within 24 hours if not treated. About half of the 104 known cases are pneumonic, the WHO said.

WHO spokesman Tarik Jasarevic told reporters in Geneva that areas affected included the capital Antananarivo and the port cities of Mahajenga and Toamasina.

The U.N. health agency said it feared that the outbreak could worsen because the season for plague, which is endemic in Madagascar, had only just begun, and runs until April. On average, 400 cases are reported each year.

“The overall risk of further spread at the national level is high,” WHO said in a statement.

(Reporting by Stephanie Nebehay in Geneva; writing by Elias Biryabarema; Editing by Kevin Liffey)

Plague Claims Another Life

Another western U.S. resident is dead because of the plague.

Officials in Utah say an elderly woman has died after contracting the potentially fatal disease earlier this month.  They could not confirm how the woman was infected but speculated that she likely had contact with a dead animal or fleas.

Utah officials would not release the name of the woman or any demographic information other than she was “elderly.”

The Centers for Disease Control (CDC) says 11 plague cases have been found this year in the U.S. and three patients have died.

“It is unclear why the number of cases in 2015 is higher than usual,” the Centers for Disease Control and Prevention stated in a brief update.

The average number of cases per year is between 5 and 6.

“Health care providers should consider the diagnosis of plague in any patient with compatible signs or symptoms, residence or travel in the western United States, and recent proximity to rodent habitats or direct contact with rodents or ill domestic animals,” the CDC says in its report.

“In humans, plague is characterized by the sudden onset of fever and malaise, which can be accompanied by abdominal pain, nausea, and vomiting.”

Second Yosemite Tourist Infected with Plague

The second tourist within a month to Yosemite National Park has been found to have contracted the plague.

The California Department of Public Health confirmed Tuesday a “presumptive positive” for plague in a patient who visited Yosemite and the Sierra National Forest in August.  The Centers for Disease Control is now testing the patient, who’s demographic information is not being released to the press.

In late July, a child from Los Angeles County became infected with the plague after camping with their family at Crane Flat Campground in Yosemite National Park.  The child is still hospitalized but recovering from the infection.

“Although the presence of plague has been confirmed in wild rodents over the past two weeks at Crane Flat and Tuolumne Meadows campgrounds in Yosemite, the risk to human health remains low,” the state Department of Public Health said in a statement. “Action to protect human and wildlife health by closing and treating campgrounds was taken out of an abundance of caution.”

Health officials say that campers should never feed squirrels and other small animals.  They also said for campers to avoid making camp near rodent burrows and to wear long pants and use bug repellant to keep the fleas that carry the disease at bay.

The plague has killed two people so far this year in Colorado.  The Centers for Disease Control says there is an average of seven human plague cases per year in the United States.

Plague Expert: “No One’s Fault” Teen Died From Plague

An expert on the plague says that the death of a teenage boy in Colorado was likely unavoidable because of how the disease presents itself.

‘You need some kind of indication from patient history that [plague] is what it is,” Dr. Robert Perry, plague researcher with the University of Kentucky, told USA Headline News.  “Septicemic is rare enough and doesn’t have really many more symptoms that anybody would think of going in real soon for that.”

“If he had gone in soon enough, and the doctors had recognized what it was, maybe he would have been OK but after a certain period of time even antibiotics are too late.”

Perry said that the symptoms that would have been presented by Taylor Gaes would have mimicked the flu until the very end.

“There was no reason anyone would have thought it was anything significant, just the flu,” Dr. Perry said.  “Nobody did anything wrong here.  The parents, the kid.”

“It could have been a dozen of viral or bacterial agents,” he continued.  “There aren’t any distinguishing symptoms to say it’s not a flu that you’re going to get over.  And once it progresses to a certain stage, it’s just too late.  It’s essentially the same as pneumonic plague.  The symptoms are pretty common to a bacteria that causes a lung infection.”

“24 to 48 hours after symptoms start to show, it’s too late to treat pneumonic plague.”

Dr. Perry said that because the bacteria went straight into the bloodstream it was classified as “septicemic.”  He said that the other two kinds of plague show earlier symptoms because the bacteria would grow in the skin or lungs before entering the bloodstream.  Once the bacteria enters the bloodstream, it immediately begins to destroy internal organs.

“Septicemic plague is basically bubonic plague that skips the earlier stages,” Dr. Perry said.

Colorado Man Infected With Rarest Form Of Plague

A Colorado man is hospitalized with the rarest and deadliest form of the plague.

Jennifer House, a spokeswoman for the Colorado Department of Public Health, said the man is infected with pneumonic plague and is the first case seen in the state since 2004.  The man’s identity is being kept from the public but officials say he was exposed in Adams County near Denver.

“He’s on treatment long enough to not be transmissible,” House told Bloomberg News.

She said that doctors believe he contracted the disease from his dog.

“We don’t think it’s out in our air,” House said. “We think it’s in our dead animal populations and dead rodent populations.”

Colorado has had 60 cases of plague since 1957 and nine people have died from the disease.  There is no vaccine available for the plague in the U.S.  The most common is bubonic plague, which was known for outbreaks during the middle ages.

“The message we’re trying to get out is that the plague bacteria is present here in Colorado, and to take necessary precautions to avoid getting infected,” House said.

Armyworms Cause Natural Disaster Areas For Farmers

Five counties in Arkansas have been declared “Primary Natural Disaster Areas” by the US Department of Agriculture due to an invasion of armyworms.

The armyworm invades grasses, small grain crops and corn primarily but can attack other crops. The worm feeds and moves at night and on cloudy days so infestations can take time to be noticed by farmers. The worms are capable of destroying entire crops. Continue reading