New study updates evidence on rare blood-clotting condition after ...
Malaria Is On The Ropes In Bangladesh. But The Parasite Is Punching Back
The soft footfalls of thousands of moccasins along unpaved rural roads across Bangladesh could be considered the soundtrack to this country's astonishing success in its battle against malaria.
On one Friday morning in December, a pair of those moccasins belongs to 42-year-old Bulbul Aktar. Here in Chakaria, in the southeast of the country, she's visiting every home in this small community by foot. It's a crucial task given the historic difficulty of gaining ground in the fight against malaria — a fight that could soon be flaring up once more.
Wrapped in a crimson shawl, Aktar approaches one of the households and shouts the standard greeting: "As-salamu alaykum!"
Asha Gudin lives here with his family. A month earlier, after working a construction job a few miles away along the border with Myanmar, Gudin spiked a fever and felt awful.
/ Fatima Tuj Johora for NPR
/
Fatima Tuj Johora for NPR
Bulbul Aktar is one of thousands of community health workers in Bangladesh — all of them women — who to go door to door to diagnose and treat people for malaria.So he sought out Aktar. She's what's called a shasthya kormi — a community health worker. Bangladesh employs thousands of these workers, all of them women, to go door to door to treat people for malaria, a disease transmitted by mosquitoes.
"This is my job, my duty," says Aktar. "Every single home, I have to know about them and visit them."
When Aktar tested Gudin for malaria, he was positive. So she gave him a drug called artemisinin.
"That night, I called him," she says, to see "how he's feeling and [if] he took his drug properly or not. After that, I called him every day at 10."
Over the three-day regimen, Gudin made a full recovery.
/ Fatima Tuj Johora for NPR
/
Fatima Tuj Johora for NPR
Asha Gudin, a malaria patient in Bangladesh, made a full recovery in three days, thanks to a quick diagnosis from a local health worker and an effective drug called artemisinin. Here, Gudin displays his treatment card."It's really pretty remarkable," says Kasturi Haldar, a microbiologist at the University of Notre Dame who studies the malarial parasite. "I mean, [the shasthya kormi] find the malaria. That's what it comes down to. And then they treat it, one person at a time, one family at a time. And then if it comes back, they come back. They're the foot soldiers of this fight."
Gudin isn't alone in his healing. Health workers say artemisinin almost never fails. "This drug is a marvelous drug. It's a perfect drug," says Dr. Ching Swe Phru who's devoted his life to treating patients with malaria in Bangladesh. (There is a malaria vaccine that's been deployed in parts of Africa, but Haldar says it won't yield rapid elimination.)
Within 12 hours, after a typical patient with high fever and excruciating pain has taken just the first four pills of artemisinin, Haldar says, "their fever was gone. I mean, that is an amazing outcome for a drug."
Artemisinin has produced astounding results across Bangladesh. And by treating infected people quickly enough to clear the parasites from their bodies, there are fewer individuals with malaria available for the mosquitoes to bite. That reduces transmission. Between 2008 and 2020, malaria cases in Bangladesh plummeted by 93%, thanks largely to this drug.
It allowed government officials in Bangladesh and elsewhere in the region to dare to imagine something audacious — malaria elimination.
"Our Prime Minister is committed. Our Health Minister is committed," says Mushfiqur Rahman, who's with Bangladesh's National Malaria Elimination Program. "We are expecting we could eliminate malaria by 2030."
But the disease won't give up easily.
A strain of the parasite turned up in neighboring Myanmar that was resistant to artemisinin. Health officials worry it's only a matter of time before a resistant strain shows up in Bangladesh.
/ Fatima Tuj Johora for NPR
/
Fatima Tuj Johora for NPR
Dr. Ching Swe Phru helps disperse bed nets treated with insecticide. Phru is grateful for the strides made against malaria but adds, "I'm afraid that malaria has a certain history of coming back.""You have to be alert," says Dr. Phru. "You have to be afraid of it. The parasites always have an inborn tendency to fight off the killing drug."
It wouldn't be the first time.
"I'm afraid that malaria has a certain history of coming back," says Phru.
Malaria is ancient but has an expanding footprintThe malarial parasite has plagued humanity for thousands of years. That history is written into our blood, which has evolved strategies to defend itself — think sickle cell disease and other kinds of anemia, which themselves can cause illness but also convey protection from malaria. "Our blood has been profoundly shaped by malaria infection," says Haldar.
Despite centuries of battling the disease, people continue to get sick from malaria, with more than 600,000 deaths every year, mostly in Africa. And its footprint is expanding as our climate changes, allowing the mosquitoes that transmit the disease to thrive in previously inhospitable regions, such as the higher altitudes of Ethiopia, Colombia and parts of Asia.
The fact that malaria is entering new terrain means the human suffering caused by the disease is also growing. Dr. Phru knows well what that's like.
In his final year of medical school some three decades ago, just before a big exam, he got hit with a terrible bout of the disease. It was his fourth tangle with malaria in a year, but this one was especially bad. "It was a very difficult time," he recalls.
While Phru tried to study, inside his red blood cells, the parasite was reproducing, eventually causing those cells to rupture. The result was agony.
/ Fatima Tuj Johora for NPR
/
Fatima Tuj Johora for NPR
Bed nets treated with insecticide to ward off mosquitoes are distributed in Chakaria, Cox's Bazar, Bangladesh."High fevers, chills and severe headaches, vomiting and nausea," he says. "The nausea was the worst. I couldn't study. My partner would recite me all the studies, and I would listen to him. And then I went for the exam with 101 or so Fahrenheit of fever. So I had to face it."
Phru was treated with a couple of drugs, including one called chloroquine. "It's a very nauseating drug and a terrible drug," says Phru. Despite the rough side effects, he was cured.
For decades, chloroquine was one of the most valuable malarial treatments worldwide. But then, gradually, the parasite stopped responding. It had developed resistance to chloroquine.
That resistance originated in southeast Asia and spread through Bangladesh to Africa until it was pervasive.
"We consider our region an important route for transmitting drug resistance," says Shafiul Alam, a parasitologist from the International Centre for Diarrhoeal Disease Research, Bangladesh (known as icddr,b).
The resulting fatalities surged into the millions, hitting sub-Saharan Africa especially hard in the 1980s. "If you don't treat people quickly," says Alam, "they may die."
That's when doctors turned to artemisinin, a compound purified from the sweet wormwood plant in the 1970s. It had taken decades to puzzle out how to make it, deliver it effectively and produce it affordably. Once the drug became available, health workers in Bangladesh were so hopeful they created a whole infrastructure around it to support the thousands of community health workers.
Now the looming resistance to artemisinin threatens all the hard-won progress of these community health workers.
The hunt for resistant strains involves a long bus rideBangladesh's border with Myanmar, where artemisinin-resistant malaria has been spotted, has researchers concerned.
/ Fatima Tuj Johora for NPR
/
Fatima Tuj Johora for NPR
Bulbul Aktar, a health worker, will make daily calls to a patient with malaria to see how they're doing.That's because much of the malaria that still circulates in Bangladesh is found in the remote hill tracts in the southeast that neighbor Myanmar. "They are now the main source of malaria," says Dr. Phru.
"About 90% [of] cases happen there and spread from there," he continues. "The health facilities are functional but sometimes they are not functional 24-7. People are underserved there. And in the far, remote areas, it is very difficult to reach."
And so malaria retains its grip.
So when people travel to the border and then return to more populated areas of Bangladesh, mosquitoes within the country can easily shuttle the remodeled parasite to new individuals. This gives resistance a foothold and opportunity to spread.
That means, says Phru, "people will die. There will be more serious patients having life-threatening conditions or about to die. And it becomes very difficult for a doctor to manage because he [has] to choose which one to attend first."
To avoid that situation, Phru says he and his team have started a program at the clinic where they draw blood from patients who have malaria but aren't responding well to artemisinin treatment. They put those samples in a cooler on an overnight bus headed for the capital.
The samples are then brought to Shafiul Alam's lab at the icddr,b, which is where University of Notre Dame microbiologist Kasturi Haldar has set up shop. She points to the glass slide on the microscope. It's in this sample where she says they found the single resistant strain of malaria within Bangladesh so far. It came from the Bandarban Sadar subdistrict in the southeast in 2018.
"If you only find one strain that's resistant," says Haldar, "it doesn't matter as long as it doesn't spread." But what she's looking for is whether that resistance is spreading.
/ Fatima Tuj Johora for NPR
/
Fatima Tuj Johora for NPR
Community health worker Bulbul Aktar handwrites her notes to keep track of the spread of malaria.The current set of samples may not tell the whole story, however. Not everyone with malaria ends up at the clinic, so it's possible there are resistant parasites circulating unnoticed in the population.
To that end, Haldar is considering enlisting the shasthya kormi health workers to collect more samples from people within the community to expand the hunt for resistant malaria. That will help her and her team get a better lock on how prevalent the disease is, identify the mutations that may be causing the resistance and then look for different drugs the parasite hasn't yet outsmarted.
Haldar is playing the long game against those parasites, one that won't be won easily. "They're complex," she says, "and they deserve your respect."
Copyright 2023 NPR. To see more, visit https://www.Npr.Org.
Mainstay Malaria Drug May Be Beginning To Fail In The Horn Of Africa
In eastern Africa, malaria parasites have developed resistance to artemisinins, the backbone of current treatment regimens, a development that could dramatically worsen malaria's impact if partner drugs fail in the future.
The finding from studies in Eritrea was reported Sept. 28 in the New England Journal of Medicine by a team of researchers led by Didier Ménard, Ph.D., of the Université de Strasbourg/Institut Pasteur in France and including Columbia University microbiologist David Fidock, Ph.D., the C.S. Hamish Young Professor of Microbiology & Immunology and professor of medical sciences in the Vagelos College of Physicians and Surgeons.
Treatment of malaria depends on artemisinin drugs paired with a partner antimalarial. These drug combinations have been highly effective treatments for non-severe cases since the early 2000s and usually clear the malaria parasites from a patient's blood after three days of treatment.
But Plasmodium falciparum parasites are developing drug resistance, which threatens to roll back the progress made against malaria between 2000 and 2015, when deaths from the disease in Africa dropped by 66%. Resistance to artemisinins first emerged in Southeast Asia in 2009, followed soon after by resistance to partner drugs. By 2016, the treatment failure rate in some parts of Southeast Asia had reached 85%. Resistance to the artemisinin components is caused by mutations in the P. Falciparum parasite gene Pfkelch13.
With drug-resistant malaria, what happens in Southeast Asia often occurs in Africa with a decade-long delay, either because resistant parasites cross over to Africa or the same mechanism of resistance takes longer to emerge and establish itself in high-transmission African settings. More than 95% of all deaths from malaria occur in Africa, and any increase in drug resistance there is alarming.
The new finding: Drug resistance in the Horn of AfricaIn the new study, Ménard's group and colleagues from the Ministry of Health in Eritrea assessed the effectiveness of artemisinin-based combination therapies in nearly 1,000 patients in Eritrea between 2016 and 2019.
The researchers found that effectiveness of the drug therapy declined during that time: The drugs failed to clear parasites in 0.4% of patients in 2016, rising to 4.2% in 2019, crossing the WHO threshold for declaring resistance.
The researchers also found that by 2019, about one in five patients was infected with artemisinin-resistant Pfkelch13 mutant parasites.
The Columbia team, led by Fidock, then performed genetic experiments with parasites grown in a laboratory and showed that the most common Pfkelch13 mutation identified in Eritrea is directly responsible for the artemisinin resistance.
The question now is how widespread the mutations in Pfkelch13 are across Africa.
"We're not looking at a new strain that's recently taken over. It's just taken this long to detect," Fidock says. "Central and western Africa have high malaria burdens, but we don't know what's happening there and need more genetic surveillance and therapeutic efficacy studies."
Parasites also escaping detectionThe situation in Eritrea is even more alarming, the study found, because many of the parasites harbor genetic deletions that make the parasite undetectable with the most common rapid diagnostic test for malaria.
About 17% of patients in Eritrea would test negative for the disease with this test, which is no longer used in Eritrea but is commonly used throughout Africa. The spread of these test-negative parasites would pose serious impediments to proper diagnosis.
"That means if somebody goes to a clinic with symptoms, but the test comes back negative for malaria, they're not going to be prescribed the right treatment," Fidock says. "Their symptoms may get worse, or they may die. This risk is compounded by the fact that artemisinins are used alone to treat severe malaria, where drugs have to be delivered intravenously. Parasites with the mutant Pfkelch13 gene may not be quickly eliminated, increasing the risk of a fatal outcome. Clinicians across the region need to be aware that patients who test negative may indeed have malaria."
Why it matters"Unfortunately, our study has revealed that resistance has established a firm foothold in the Horn of Africa, which makes it more likely that the partner drugs will fail next because they are not being eliminated by the artemisinin, and malaria cases and deaths may start to spike," says Ménard.
The situation is not yet catastrophic, because the parasites have not developed resistance to the partner drugs used in artemisinin therapy.
"But if those partner drugs fail, the situation could quickly worsen," Fidock says. "There are enormous efforts underway to develop new drugs, but right now there are very limited options available."
More information: Increasing Prevalence of Artemisinin-Resistant HRP2-Negative Malaria in Eritrea, New England Journal of Medicine (2023).
Citation: Mainstay malaria drug may be beginning to fail in the Horn of Africa (2023, September 27) retrieved 28 September 2023 from https://medicalxpress.Com/news/2023-09-mainstay-malaria-drug-horn-africa.Html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
What Are Parasites?
Medically reviewed by Josephine Hessert, DO
Parasites are organisms that infect other living things to survive, live, feed, and reproduce on or inside them. Many types of parasites affect humans. In fact, these organisms can spread through food, water, bug bites, and sexual contact. If a parasite feeds on you, you can develop a parasitic infection. The symptoms of parasitic infections vary a great deal, but most people may experience diarrhea, nausea, vomiting, rashes, and fever.
Since parasites depend on your body for survival, they don't often cause infections that are deadly. However, some parasitic diseases like malaria can be life-threatening. That's why it's important to understand what parasites are, the signs of infection, your treatment and management options, and how you can prevent exposure.
What Are Parasites?A parasite is any organism that lives and feeds on or inside another organism (known as the host). By nature, the way a parasite gets nutrients and reproduces is at the expense of that host organism. A host can be any other living thing, such as a human or another animal. Single-celled organisms, amoebas, worms, ticks, fleas, and lice are among the many types of parasites that infect humans.
Types of ParasitesThere are three main types of parasites that infect humans: protozoa, helminths, and ectoparasites. Each type is unique in the ways it spreads, multiplies, and affects your body.
ProtozoaProtozoa are single-celled organisms that infect your body and multiply inside it. These parasites spread to you by either direct contact with the skin or via mosquitos, pets, or ticks. Once they make contact with you, protozoa enter the bloodstream and spread to the lungs, intestines, heart, and pancreas.
Types of protozoa that affect people include:
Babesia: Babesia infect the bloodstream, causing a rare infection that may cause flu-like symptoms
Giardia duodenalis: This type causes a giardia infection, which is one of the most common causes of diarrhea
Cryptosporidium parvum: Often spread through contaminated drinking or swimming water, cryptosporidium parvum, or "crypto" causes diarrhea
Plasmodium: This class of protozoa causes malaria, which is a severe and deadly disease that's more prevalent in tropical and subtropical climates
Toxoplasma gondii: A type of protozoa that causes fever, swollen glands, and muscle aches
Helminths are multi-cellular, worm-like organisms that are usually visible to the naked eye in their adult stages. These parasites typically affect the intestines, bloodstream, or tissues beneath the skin. Helminths are only able to multiply inside the body in their younger stages. There are three primary types of helminths that affect people, including:
Flatworms: Also known as platyhelminths, flatworms are worms that have no segments. Tapeworms and cestodes are subtypes of flatworms that grow in the intestine, while trematodes are a subtype that can affect the liver and lungs.
Roundworms: Adult forms of roundworms or nematodes are commonly found in the gastrointestinal tract, lymphatic system, blood, or tissues below the skin. In other cases, larval or immature roundworms can also infect tissues in the body.
Thorny-headed worms: These parasitic worms, also called acanthocephalans, have thorny hooks at one end that latch onto your intestinal walls. These parasites spread through soil or contact with feces. The most common types of thorny-headed worms that affect people are hookworm, ascariasis, and whipworm.
Ectoparasites are ticks, fleas, lice, or mites that attach or burrow into your skin. These parasites can stay in your skin for weeks or even months. Not only do they cause health problems, but ectoparasites are also vectors (or, carriers) of more serious viruses and bacteria.
What Do Parasites Look Like?Since there are many different kinds of parasites, each type can come in its own unique shapes and sizes. The three main types of parasites all have a distinct appearance.
ProtozoaAs single-celled organisms, you need a microscope to see protozoa from the human eye. There are four types, which are classified by how they move:
Sarcodina, or amoeba, which are blob-like and temporarily project their body to move
Mastigophora, or flagellates, which move using hair-like strands called flagella
Ciliophora, which have cilia, or hair-like projections that are shorter flagella
Sporozoa, which do not move and form spores to spread
Helminths may be microscopic in their larval stages but are visible when they are fully grown. You can find these parasites in your feces (poop). Tapeworms are ribbon-like and develop segments. But, other flatworms don't usually have segments. Thorny-headed worms have distinctive horns on one end. Roundworms, such as nematodes, appear round and spirally.
EctoparasitesEctoparasites are a diverse type of parasite. They include:
Ticks, which have eight legs and tend to be small and dark-colored
Head lice, which are six-legged tan or gray-colored insects that are the size of sesame seeds
Mites, which appear as tiny black dots that cause raised lines on the skin
Fleas, which look like small dark brown or red insects with a hard exoskeleton
The specific symptoms of a parasitic infection depend on the exact parasite that infected your body, how severe your infection is, and which part of the body is affected. However, some common symptoms to look out for include:
How To Know if You Have an InfectionIf you're experiencing symptoms of a parasitic infection, it's good practice to see your healthcare provider for proper testing. Your provider will first take your medical history and ask about any recent travels. In addition, they may perform several laboratory tests, including:
Fecal stool sample: If you have gastrointestinal symptoms like diarrhea or nausea, your provider will need to perform a fecal stool exam, or ova and parasite test. You will have to take a sample of your stool (poop) and then send it to a lab so a technician can screen your sample under a microscope to check for parasites or eggs.
Endoscopy or colonoscopy: This diagnostic test allows your provider to look inside the intestines for signs of parasites or other disease. With endoscopy, your provider inserts an endoscope (or, a camera that is attached to a specialized tube) through your mouth. A colonoscopy also uses an endoscope, but this exam puts the endoscope through your anus.
Blood tests: Blood tests can detect certain parasitic infections, which can help your provider understand what's causing your symptoms. One type of blood test, called serology, detects antigens, or chemicals that your body releases as a part of your immune system response. Another common test, known as the blood smear, involves analyzing a sample of your blood under a microscope to detect malaria, babesiosis, and other infections.
Imaging exams: X-rays, magnetic resonance imaging (MRI), or computerized axial tomography (CAT) scans are all imaging methods that your provider can use to detect parasites that may be present in your organs.
What kind of parasite you have determines your exact treatment plan. Generally, parasitic infections don't go away on their own and require some type of antiparasitic medication. Your provider may also prescribe antibiotics or antifungal medications, depending on the symptoms you're experiencing. Most medications are oral pills, but you can apply some treatments as topical creams on your skin.
The most common treatments include:
Antiprotozoal drugs: Chloroquine (chloroquine phosphate), Humatin (paromomycin sulfate), and Fansidar (sulfadoxine/pyrimethamine)
Antihelminthic agents: Bilitricide (praziquantel) and Albenza (albendazole)
Antiscabietic creams: Sklice (ivermectin), Elimite (permethrin 1%), and Kwell (lindane)
Anti-lice lotions: Ulesfia (benzyl alcohol 5%) and Ovide (malathion 5%)
Over-the-counter lice treatments: Elimite (permethrin) and Pronto (piperonyl butoxide)
There are several strategies you can take to prevent exposure to parasites. These include:
Washing your hands frequently and thoroughly, especially when handling food
Taking hygienic measures when cleaning up dog or cat poop and disposing it properly
Following safe food handling procedures, cooking food thoroughly, and washing vegetables
Keeping your pet up to date on veterinary care and vaccinations
Following travel advisories regarding food and drink when traveling abroad
Taking antimalarial drugs before traveling to regions that have higher rates of malaria
Wearing insect sprays to prevent tick bites
Parasites are organisms that live inside or on your body, which survive and multiply at your expense and make you sick. Ranging from single-celled organisms to lice or ticks, parasites can cause a wide variety of infections. Common signs of parasitic infections include diarrhea, nausea, abdominal pain, and fever, among others. Talk to your healthcare provider if you suspect that you have an infection. Your provider can help determine the exact treatment you need to improve your symptoms.
For more Health.Com news, make sure to sign up for our newsletter!
Read the original article on Health.Com.
View comments
Comments
Post a Comment