Sunday March 24, 2019

Study: Fever, chills, And Muscle Pain Could Be Signs Of Leptospirosis

Fever, chills, and muscle pain aren’t the symptoms just of malaria

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A herdsman walks his cattle as they graze in Naivasha, Kenya, Feb. 15, 2018.
A herdsman walks his cattle as they graze in Naivasha, Kenya, Feb. 15, 2018. VOA

Fever, chills, and muscle pain aren’t the symptoms just of malaria. They could be signs of leptospirosis, which infects millions of people each year — primarily in tropical regions.

The under-reported disease is usually spread though contact with rodents, but a new study finds this trend may not hold in northern Tanzania or beyond.

Research in Asia has tied living in close quarters with rats to outbreaks of leptospirosis. The bacterial infection causes symptoms that are often mistaken for malaria. Severe cases can be life-threatening, says Professor Albert Ko at the Yale School of Public Health.

“Our group has done global burden of disease studies on this and there are over a million a cases a year and roughly 60 thousand deaths,” said Ko.

Common source of fevers

Leptospirosis is becoming recognized as a common source of fevers in Africa. But the source of the disease was unclear. It could be rats, or it could be something else, said Michael Maze, of the University of Otago.

“Well, we know that leptospirosis has many possible animal hosts,” said Maze. “I guess the story starts when we identified how common leptospirosis was the cause of severe fever in people coming to the hospital in northern Tanzania.”

Maze and an international team of researchers asked those patients about their lifestyles: how many rats they saw around their home… whether they owned livestock and if so, what kind?

They also tested blood samples for leptospirosis infections. Of the nearly 900 people tested, almost a third were infected, or had been.

The researchers also trapped almost 400 rats in nearby villages. They tested the rodents to see if they carried the leptospira bacterium like their Asian cousins. They did not.

But cattle did — they found over seven percent of them carried up to four types of leptospira that could potentially infect humans. Goats and sheep did, too, though less often.

cow
cow, Pixabay

Blood samples match

This result matched the findings from the patients’ blood samples. People who owned livestock were most likely to have leptospirosis infections, especially cattle owners.

“Leptospirosis is carried in the renal tract — so the kidney and the bladder — and comes out in the urine of infected animals,” said Maze. “So even simple things like avoiding urine while doing activities such as, for example, milking cattle would be a good first step.”

Maze recommends abattoir workers and dairy farmers wear gloves and other protective clothing.

“A cow is much bigger and it produces a much larger volume of urine and so that creates a greater opportunity for exposure,” said Maze.

But Maze and colleagues found doctors did not diagnose a single one of the patients in the study with leptospirosis. In fact, one in four active cases was misdiagnosed as malaria — even though the patients’ blood tested negative for parasites.

Symptoms similar

Maze says one reason is because symptoms of the two diseases are similar and there is not an accurate, simple test for leptospirosis that can be run in regional hospitals.

“The second reason is that clinician awareness of these diseases is low,” said Maze. “If you don’t recognize them it becomes a cycle where they’re never diagnosed so you never recognize them.”

Yale’s Albert Ko says the work Maze and his colleagues have done provides a better understanding of how leptospirosis spreads.

Also read: The outbreak of Leptospirosis with monsoon: Symptoms and precautions

“This is an important study specifically because it provides key information on risk factors in a high burden setting, said Ko. “In specifically among this at-risk population of vulnerable pastoralist society.” (VOA)

Next Story

Novel Experimental Vaccine Offering Hope Against Malaria

A year later, the vaccinated non-human primates still had immunity against malaria, while eight control animals that were not vaccinated did not

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Malaria, Vaccines
This new type of bed net can help prevent malaria: Lancet. (VOA)

An experimental new malaria vaccine is offering potentially long-lasting immunity against the persistent parasite that sickens hundreds of millions of people each year, a study suggests.

Most vaccines are designed to encourage the human body to respond to invading, disease-causing pathogens by creating antibodies that disable those pathogens.

However, the new vaccine takes a different approach by using a weakened form of a common herpes virus – cytomegalovirus, or CMV – that infects most people without causing the disease.

This new vaccine reduced the malaria-causing parasite’s release from the liver and into the blood of infected rhesus macaques by 75 to 80 per cent, reported the paper published in the journal PLOS ONE.

“The problem with most vaccines is that their effectiveness is often short-lived,” said lead author Klaus Fruh, professor at the Oregon Health and Science University in the US.

More people die of malaria than anything else in the world.
More people die of malaria than anything else in the world.

“Our cytomegalovirus-based vaccine platform can create and keep immunity for life. With further research and development, it could offer a lifetime of protection against malaria,” Fruh added.

Malaria is a serious and sometimes fatal disease caused by Plasmodium parasites, which are spread to humans through mosquito bites.

It can cause high fevers, shaking chills, flu-like illness and, in the worst cases, death.

Worldwide, 216 million people were infected with malaria in 2016, leading to 445,000 deaths.

Fruh and his team weaved tiny bits of their target pathogen into CMV, which is already being used in vaccines being developed to battle HIV and tuberculosis.

Those who receive the resulting, re-engineered CMV vaccine produce memory T-cells that can search for and destroy pathogen-infected cells.

A health service worker takes a blood sample for a malaria test in Dajabon, Dominican Republic, on the border with Haiti, Oct. 6, 2009. A test that doesn't require a needle or blood has won the Africa Prize for Engineering Innovation
A health service worker takes a blood sample for a malaria test in Dajabon, Dominican Republic, on the border with Haiti, Oct. 6, 2009. A test that doesn’t require a needle or blood has won the Africa Prize for Engineering Innovation, VOA

The team developed two different versions of their CMV-based malaria vaccine while using four different proteins made by the Plasmodium parasite.

The resulting vaccines delayed the parasite’s appearance in the blood of 16 infected and vaccinated rhesus macaques by eliminating between 75 and 80 per cent of parasites from the liver.

Also Read- Deficiency of Zinc May up Hypertension

A year later, the vaccinated non-human primates still had immunity against malaria, while eight control animals that were not vaccinated did not.

The CMV vaccine platform has been licensed by San Francisco-based Vir Biotechnology, which plans to lead a human clinical trial for a CMV-based HIV vaccine in 2019.  (IANS)