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Lessons Learned in Lilongwe (and a bit of science too!)

Hi friends!

I had a special opportunity to write an article for the Brunswickan and if you’re interested in checking it out, you can click on the link here. As my last post, this article sums up the internship that inspired this whole blog! I’ve really enjoyed reading your blogposts and learning alongside you all throughout the semester. 

For the last time (how sad)... I’m OFF.

Lua

[lsamimi-blog]

Deadly Blood.

(Image source)

If you could have any superpower in the world, what would it be? The power to become invisible? To fly? To read minds? What about the power to make a mosquito drop dead at the taste of your blood?

A recent study published in The Lancet Infectious Diseases has found a new potential malaria control tool – the antiparasitic medication ivermectin. Contrary to most malaria drugs, ivermectin is aimed at killing the Anopheles mosquito vector (responsible for transmitting the parasite from host to host) rather than the actual Plasmodium parasite itself. And what causes these blood-suckers to fall to their death? None other than your blood.

Here’s our good friend the “poorly-illustrated mosquito” again – this time, dead due to ivermectin in the blood meal.

Researchers from the Liverpool School of Tropical Medicine and the Kenya Medical Research Institute tested the effects of ivermectin co-treated with an existing antimalarial medication, dihydroartemisinin-piperaquine (DP). Ivermectin is typically used in low doses to treat a number of parasitic infections, including elephantiasis and river blindness. The standard dose is 150-200 μg/kg per day, but the drug is still safe at doses over 10X that amount!

The goal of this study was to determine high doses of ivermectin that were effective at killing mosquitoes, but still safe for widespread human administration. Any adults aged 18-50 who were diagnosed with symptomatic uncomplicated Plasmodium falciparum malaria were able to join the randomized, double-blind study. All participants were randomly assigned a treatment group: either 0, 300, or 600 μg/kg per day ivermectin, co-treated with DP for 3 days. The group without ivermectin acted as a control.

Blood samples were taken from the patients after 2, 7, 10, 14, 21, and 28 days post-treatment. The blood was put in fake “membranes” to mimic human skin and blood vessels, then the blood-filled membranes were placed in cages with laboratory mosquitoes. Researchers watched as the mosquitoes freely fed on the blood for up to 28 days.

And what happened next is something straight out of a horror movie… One by one, the blood-suckers started dropping dead! Well, not literally. But ivermectin treatment did increase mosquito mortality rates. In the high dose (600 μg/kg ivermectin per day) group, a shocking 97% of mosquitoes were dead after only 2 weeks of feeding. Most mosquitoes feeding on blood from the lower dose group also died by 14 days, but to a slightly lesser degree. As for the mosquitoes that fed on the control blood? Only 41% died after 2 weeks (most likely due to natural causes or potentially as a result of the DP treatment).

Mosquito mortality rates in three different treatment groups. 

The scientists in Kenya then recruited their colleagues at the Imperial College in London to predict ivermectin’s effect on malaria control. Using their experiment’s data and a fancy mathematical model, the mathematicians found that adding ivermectin to the already-used DP treatment could reduce malaria transmission by up to 61% (compared to DP treatment alone)! For a disease that currently affects over 215 million people worldwide, this reduction is worth celebrating.  

Now here’s the really interesting bit. A previous study also found that ivermectin was effective at killing mosquitoes, but their effects only lasted up to 7 days post-feeding. However, this study found that mortality effects actually lasted up to 28 days. So in other words, ivermectin not only transforms humans into mosquito-killing machines, but our superpowers can last for nearly a month!

And now you’re probably wondering, “Okay, but what about safety? If this drug can kill mosquitoes, it’s probably not too good for humans, right?” Out of 45 patients given the high drug dose, only 5 reported any adverse reactions – and they were mainly minor visual disturbances. One patient, however, did go into anaphylactic shock, so it’s important to be aware of all allergies before starting any treatment. It’s also important to note that side effects do appear to be dose-dependent. In the lower dose group, only 4% of patients had treatment-related side effects (compared to 11% in the high dose). So at the levels administered in this study on the patients tested in this study, ivermectin seems to be fairly safe.

Now… here’s the “but”. Although the results of this study are promising, more research is needed before ivermectin is actually incorporated into malaria treatments. First of all, the drug effects need to be tested on healthy adults as well. The participants were all symptomatic patients who were already hospitalized for their malaria diagnosis. Picture this: if you’re already not feeling well, you’re probably less likely to notice minor changes in your health. Also, most malaria control strategies target children, so the effects on younger patients must be studied. Finally – as with any drug – mosquitoes could evolve resistance if ivermectin becomes widely used, so the mechanism by which the drug kills mosquitoes needs to be better researched. With all of this being said, we still have quite a ways to go before eradicating malaria, but this study may have put us one step closer.

The discovery of new malaria therapies is especially important with the current rise of insecticide-resistant mosquitoes. This new combination is a double whammy for the stubborn malaria endemic; not only does DP attack the parasite inside our bodies, but ivermectin also joins in to kill the mosquito vector. It’s like a final kick to really make sure the parasite doesn’t spread. You can never be too sure, right? Plus, we get to walk around with deadly blood.

That’s all for now! I’m OFF.

Lua

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Malaria Vaccine? It’s Worth a Shot!

Photo taken during routine immunizations at Kauma Village Clinic in Malawi. 

Have you heard the old quote “prevention is the best medicine”? The author is unknown, but whoever it was had a point! Literally.

A new malaria vaccine called RTS,S is currently undergoing Phase III clinical trials and is set to be piloted in Kenya, Ghana, and the country that inspired this whole blog – Malawi. The drug acts against Plasmodium falciparum, which is the deadliest and most common malarial parasite in Africa. Although some similar vaccines have since been developed, RTS,S was the first in the world (created in 1987!) and is recommended by the World Health Organization (WHO). It is also the only malaria vaccine to show protection for young children in Phase III trials. In fact, researchers in these trials found that it decreased mortality by nearly 50%!

For most effectiveness, the vaccine will be given through an intramuscular injection in four doses. The first dose is given at five months old, the following two are given in monthly intervals, and the fourth dose is administered around the age of two. And what about the side effects? Generally, there are none! Some mild pain and swelling may occur at the injection site and in rare cases, there have been reports of fever-induced seizures. However, children who experienced these seizures recovered fully.

So, why is this so relevant? Well, after 31 years of research, the time has finally come! This year, WHO is coordinating the first Malaria Vaccine Implementation Programme in order to address the real-world implications in terms of safety, dosage, feasibility, and efficacy. The vaccine will be incorporated in routine immunization programs across the three pilot countries with a goal of vaccinating at least 360,000 children every year! 

Will this be the future of malaria control in Sub-Saharan Africa? Only time will tell. 

For more information on the vaccine itself, feel free to check out this paper: https://www.sciencedirect.com/science/article/pii/S0264410X10007218

And make sure to check the WHO website for updates on the pilot program!

That’s all for now. I’m OFF.

Lua

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Why Did the Chicken Cross the Road?

Image source

Next time you find yourself browsing for a mosquito repellant in Walmart, you might want to try the poultry section! A study published in the Malaria Journal last year found that mosquitos which carry the malaria parasite are not too fond of odours given off by chickens.

Despite global efforts to eradicate malaria, it continues to be a major public health threat. Sub-Saharan Africa is a particular region of interest because it accounts for approximately 90% of deaths caused by malaria. The majority of these are children under 5 years of age.

Malaria is a serious disease caused by a Plasmodium parasite and transmitted to humans by a female Anopheles mosquito. There are five known species of Plasmodium that can infect humans, but Plasmodium falciparum tends to be the most lethal. Once the mosquito is infected, it buzzes around, preying on its next victim. The Anopheles mosquito has a broad host range, so it can prey upon a bird, goat, sheep, chicken, or YOU! When the time is right, the Anopheles mosquito will bite into its chosen meal and transfer the parasite to the bloodstream of its new (and unsuspecting) host. The parasites will multiply in the host’s liver, then return to the bloodstream to infect healthy red blood cells. Here, Plasmodium further multiplies, then wreaks havoc by bursting open the membrane and infecting other red blood cells. Some of the parasites will remain in the host’s liver – resulting in recurring illnesses – while others stay in the red blood cells, patiently waiting to be transferred to their next victim during the following blood meal.

Figure 1. Stages of Plasmodium transmission in a vertebrate host. 

Among the various Anopheles mosquitoes, A. arabiensis is a major carrier of malaria in Sub-Saharan Africa. It can feed on a variety of vertebrate hosts and poses a great challenge for malaria control. In hopes of developing better control strategies, researchers in Ethiopia conducted a number of experiments in three villages.

They first caught 4844 mosquitos from four Anopheles species and confirmed that A. arabiensis was, in fact, the most abundant (accounting for more than 98.5% of the captured mosquitos!). Next, to test for host preference, blood samples were taken from mosquitos that had just taken a blood meal from either human, cattle, goat, sheep, or chicken hosts. The researchers found that humans and cattle were the preferred hosts, with some mosquitoes also feeding on goat and sheep. But what about the chickens? Only one out of nearly 3200 chickens was bitten.

Okay, so it seems the mosquitos carrying malaria really don’t like to feed on chickens. But why? A. arabiensis has been known to distinguish between preferred and non-preferred hosts using its sense of smell. Some hosts give off attractive chemicals, while others have shown to release repellants. The authors hypothesized that chickens must be releasing an odour that these mosquitos simply don’t like… but what is that specific odour? And could it potentially be used for malaria control?

To solve this mystery, the researchers collected hair, wool, or feathers from the animals and sealed them in a bag, then analyzed the gas chemicals being released. And here’s the really cool part – they found four compounds that were specific to chickens! Hexadecane, naphthalene, isobutyl butanoate, and trans-limonene oxide were identified as non-host volatiles (consider them the equivalent of a skunk’s repelling odour for humans).

The researchers also performed field experiments in 11 homes in the Ethiopian village of Wama Kusaye. Each of the 11 volunteers was given an untreated mosquito net to sleep under, with a mosquito trap attached at the foot of the bed. A chemical dispenser was also placed near the trap and was programmed to release 1mg of a specific compound every hour. Nine of the homes were given host-identified compounds (four of which were unique to chickens), one was given a solvent as a control, and one was given a live, caged chicken in place of a chemical dispenser. The results were astounding!

Compared to the control solvent, there were significantly fewer mosquitos caught in traps sprayed with chicken-specific compounds. Interestingly enough, the live chicken acted in a similar repelling manner and significantly reduced the number of mosquitos.

With the rise of insecticide resistance, it is becoming more and more important to discover new vector control strategies. Mosquitos with broad host ranges, such as Anopheles arabiensis, are extra challenging to tackle, so the discovery of natural repelling compounds is extra promising (added bonus for staying away from potentially harmful chemicals like DEET)! However, it is important to take this all with a grain of salt.

The experiments were done using very small sample sizes and did not account for differences in the participants’ individual mosquito-attracting properties. Although they successfully identified new repellant chemicals, the researchers also did not explore the mechanisms by which these chicken-specific compounds work. Perhaps the evaporated odours confuse the mosquitos by blocking their sense of smell. Or perhaps the odour is so repulsive that they run (ahem – fly) in the opposite direction. Better yet, maybe the chickens are actually eating the mosquitos!

Future research should focus on these identified compounds to determine the most effective ones, the necessary concentrations, and durations of protection. In the meantime, before we jump to housing chickens, the best form of protection is still long clothing and conventional mosquito repellants. 

That’s all for now. I’m OFF. 

Lua

[lsamimi-blog]

The new malaria medication that BLUE my mind

Image source

How attached are you to the colour of your urine? Scientists in Mali have discovered a new drug combination that was found to be effective at killing malaria parasites. The only downside? It turns your urine as blue as a smurf!

Although there are currently a number of treatments available, malaria continues to be one of the most life-threatening diseases in the world. Many malarial parasites have developed resistance to commonly used medications, so scientists are now testing out a variety of drug cocktails to kill the Plasmodium parasites faster. The most recent discovery is the combination of an existing antimalarial drug, artemisinin, and a conspicuous blue dye called methylene blue.

This blue dye is traditionally used to stain tissues, but has also been used as a treatment for urinary tract infections and is 100% safe for human use. This study found that methylene blue is effective at killing the malarial parasite during the gametocyte stage – the only time in Plasmodium’s life cycle where it is infectious to mosquitoes. Most current antimalarial drugs don’t target the gametocyte stage, so humans can continue to spread the disease a few days after treatment.

Patients treated with this new combination of artemisinin and methylene blue were clear of all malarial gametocytes within two days. Two days. They were free of symptoms AND no longer able to transmit the disease. So we’ve cured malaria forever, right?

Not quite. It turns out that humans are not too thrilled with the idea of bright blue urine. Although the dye was found to be completely harmless, there seems to be a negative connotation with brightly coloured chemicals (so much so that 25% of participants said they would not take the medication). So there you have it folks… blue urine. 

Would you try the treatment? Let me know in the comments!

Lua

[lsamimi-blog]

InteresTED in learning about malaria?

“Malaria is a normal problem of life.”

Did that quote make you feel a bit uneasy? Confused? Maybe even angry?

Canada sees an average of 488 cases of malaria every year. Let’s think about that number for a minute. This means that among the nearly 37 million people living in Canada, only 0.001% will be affected by this mosquito-borne illness. Okay, so maybe malaria isn’t a “normal problem of life” in Canada. But here’s the issue: outside of Canada (and our friendly country-neighbours down below), malaria affects over 214 million people every year - that’s nearly six times the population of Canada.

So malaria IS a big deal, after all. But are there treatments available? Absolutely! Can we prevent it? Sure can. Do we have scientific background on the parasite that causes it? Yep. If all of this is true (I can assure you it’s not fake news), then why does malaria continue to kill nearly half a million people every year? Why has this treatable, preventable disease killed more humans than any other infectious disease?

This incredible Ted Talk by Sonia Shah outlines the 3 reasons we still haven’t gotten rid of malaria. I first watched this video during a sustainable healthcare workshop and was really intrigued by the mosquito net story (click the link to find out what happens when you give free mosquito nets to people in high risk malaria zones - the results may surprise you)! I love how Sonia Shah explores malaria in a holistic manner by outlining the scientific, economic, and cultural challenges that contribute to this global issue. This video is a great preface to my blog and I hope you enjoy it!

Until next time! I’m OFF.

Lua

[lsamimi-blog]

Here’s the buzz.

“What’s the difference between a fly and a mosquito? A mosquito can fly, but a fly can’t mosquito!”

Okay... now that we’ve established I’m most certainly not a comedian, let’s explore who I am and why I started this blog:

Hi friends! My name is Lua and I’m a 4th year Biology student at the University of New Brunswick. I grew up in the small town of Hanwell, but have lived in Fredericton for most of my life (talk about big city dreams!). If I had to give you a breakdown of my typical day, I’d say around 50% is spent counting cancer cells in my honours lab, 15% jamming out to early 2000′s hits, 13% eating too much food (with lots of cheese, please!), 12% crying to “This Is Us” on Netflix, 8% doing some sort of physical activity (I love hiking and have recently started Zumba), and 2% sleeping (yes - the bags under my eyes are designer).

The view at the end of a 3 day hike (Mount Mulanje, Malawi).

But that’s enough about me. I’m sure you’re all ITCHING to know why I chose to start a blog about malaria, so here it goes. Disclaimer: this is where things get a bit more serious, because hey - it’s hard to laugh at a disease that claims the lives of nearly half a million people every year. 

This past summer, I had the unique opportunity of completing an internship in Malawi through the Queen Elizabeth Scholarship program. Over the years, I had developed a strong interest in global health through past international experiences, so my goal for this internship was to learn ALL about Malawian healthcare - the good, the bad, and the ugly! I was fortunate enough to work alongside some incredible local physicians who provided me with first-hand experience by touring hospitals, clinics, and diagnostic labs.

Here I am, casually standing in front of a wild African elephant. Casually.

Before my internship, I thought I knew everything there was to know about Malawi’s malaria menace (try saying that five times fast). I had read the stats on the WHO website, I was taking daily anti-malarial pills, and I had aced my Parasitology course the year before, so of course I understood the risk for malaria, right?! Wrong.

The more time I spent in Malawi, the more aware I became of the severity of this disease. Throughout my three month internship, I met countless small children who had been recently diagnosed and were fighting for their lives. In fact, malaria affects an annual 215 million people worldwide and the majority of those are young children.

The most special moment with a very special little boy. One of my favourite memories.

Although there are medications available, treating malaria isn’t as simple as 1-2-3 and this blog will examine why that may be (hey I’m a poet and I didn’t even know it). I’ll also explore health disparities, the science behind this endemic disease, and some exciting new treatment strategies! If you’re interested in learning more, please give that follow button a click! And if you ever have any questions or comments, I’d love to hear from you.

Well, that’s all for now. I’m OFF! (Get it... like the mosquito repellant... No? Okay.)

Lua