Malaria: Parasite or virus? Part 2
So what are you thinking?
Given that malaria appears to be more of a lifelong, chronic disease, the virus theory lends itself nicely; a virus could be both acute and/or chronic, whereas the unicellular parasite is identified with acute symptomology, rather than chronic, or recurrent symptoms. Many viruses, whose genetic information is not integrated into the host DNA, may lie dormant in tissues for long periods of time without causing much, if any, tissue damage. Viral infection does not always result in cell death or tissue injury; in fact, most viruses lie dormant in tissue without ever causing pathological effects, or they do so only under other provocations, such as trauma, another infection, emotional stress, menstruation, various illnesses and environmental factors. Plant RNA viruses must rely on insects with a proboscis to get them into a host cell; they do not ordinarily multiply in the insect but simply reside on its proboscis.
Anopheles vectors of human malaria in Africa and Asia are colonized by RNA viruses, some of which are monophyletic but clearly diverged from other arthropod viruses. The interplay between small RNA pathways, immunity, and the virome may represent part of the homeostatic mechanism maintaining virome members in a nonpathogenic state, and could potentially influence vector competence.
Were the plasmodium parasites formerly plants?
Professor Geoff McFadden, a plant scientist at the University of Melbourne, discovered that the Plasmodium parasite contains within its single cell, a small, relic chloroplast. In plants and algae cells, chloroplasts contain the essential chemical compounds for photosynthesis—the process that gives plants their energy.
Earlier in the parasite's evolution, the chloroplast was probably used for photosynthesis. Now, it contains genes required for fatty acid and isoprene metabolism, which produces compounds that are essential for the parasite’s survival. It could have a plant virus embedded in its nucleic acid and that is what is causing malaria symptoms.
How does a mosquito become infected (according to the Plasmodium parasite belief)?
When a mosquito bites an infected individual, the sporozoan's male and female sexual stages, or gametocytes, are taken up in the blood meal. Fertilization ensues in the mosquito's gut, and an "ookinete" forms. The ookinete then bores through the mosquito's stomach wall, becoming an oocyst, which subsequently divides to produce about a thousand infective sporozoites. In P. falciparum this process takes five to seven days, after which the sporozoites are released. They then migrate to the insect's salivary glands. Because mosquitoes inject their saliva when they bite (it contains anticoagulants and local anesthetic substances that facilitate blood sucking), the malaria sporozoites will be passed along to the mosquito's next victim.
Once inside the bloodstream of the bitten individual, the sporozoites search for the liver. Each sporozoite invades a separate liver cell, and in P. falciparum takes five to seven days to divide and produce thousands of "merozoites," each of which will infect a red blood cell (erythrocyte) when the liver cell bursts. After entering the erythrocyte, the merozoite breaks down the cell's hemoglobin, feeding off the amino acids. The growing parasite, or trophozoite, will eventually become a "shizont" when it begins to divide again to form new merozoites. This erythrocytic cycle takes a variable amount of time in different malaria species--48 hours in P. falciparum but 72 hours in P. malariae infections. (P. vivax or P. ovale infections may not produce merozoites immediately but may linger for a year or more in the liver before activating. This stage is known as a hypnozoite and can cause a relapse of malaria many months after an apparent cure.)
Steps to infection by a virus
The first key step in infection is recognition: a virus has special surface molecules that let it bind to receptors on the host cell membrane. Once attached to a host cell, animal viruses may enter in a variety of ways:
by endocytosis, where the membrane folds in; or,
by making channels in the host membrane (through which DNA or RNA can be injected);
by fusing with the membrane and releasing the capsid inside of the cell (enveloped virus).
After the virus uses the host cell's resources to make new viral proteins and genetic material, viral particles assemble and prepare to exit the cell. Enveloped animal viruses may bud from the cell membrane as they form, taking a piece of the plasma membrane with it. Non-enveloped virus particles, such as rhinoviruses, typically build up in infected cells until the cell bursts and/or dies and the particles are released.
Signs and Symptoms of Malaria
Characteristic signs of malaria infection are fever and flu-like symptoms, including headaches and muscle or joint pain. Malaria may cause anemia and jaundice (yellow coloring of the skin and eyes) because of the loss of red blood cells. If not promptly treated, the
infection can become severe and may cause kidney failure, seizures, mental confusion, coma, and death. These symptoms usually begin after an incubation period of 10 to 14 days after the infective bite, during which the malaria parasite first inhabits the liver and then quietly multiplies in the blood. Usually, the fever is intermittent, recurring every few days, corresponding to the erythrocytic cycle. Each time the infected cells burst, liberating new merozoites, toxic metabolites and malarial antigens are also released. The body's immune system responds with a fever. Malarial fevers, especially in P. falciparum infections, do not always show cyclic temperature changes. P. falciparum malaria can kill within 48 hours of the first signs, so it is essential that medical help is sought if one develops such symptoms after a visit to a region where malaria is a problem.
Malaria deaths are usually related to one or more serious complications, including:
Cerebral malaria. If parasite-filled blood cells block small blood vessels to your brain (cerebral malaria), swelling of your brain or brain damage may occur. Cerebral malaria may cause seizures and coma.
Breathing problems. Accumulated fluid in your lungs (pulmonary edema) can make it difficult to breathe.
Organ failure. Malaria can damage the kidneys or liver or cause the spleen to rupture. Any of these conditions can be life-threatening.
Anemia. Malaria may result in not having enough red blood cells for an adequate supply of oxygen to your body's tissues (anemia).
Low blood sugar. Severe forms of malaria can cause low blood sugar (hypoglycemia), as can quinine — a common medication used to combat malaria. Very low blood sugar can result in coma or death.
Diagnosis and Treatment of Malaria
Diagnosis can be done through microscopy, antigen-based rapid diagnostic tests (RDT) and polymerase chain reaction tests (PCR).
The discovery that Plasmodium was once a photosynthetic organism that somehow evolved to become the parasite it is today led to a new way of treating people infected with the parasite. The aim is to stop the parasite reproducing while not affecting the cells of the human host. Obviously, humans don’t have chloroplasts, so a drug that targets only the chloroplast is an ideal option. Millions of people are now protected from malaria by a drug known as doxycycline, which inhibits a gene that McFadden identified in Plasmodium.
Chloroquine is a synthetic medication for antimalarial therapy derived from quinine. Artemisinin, and its derivative, artesunate with sesquiterpene lactone backbone, is an antimalarial agent originated from Artemisia annua which has been used in China for centuries to detoxify blood and eliminate fever.
Today, the recommended treatment for malaria is artemisinin along with either mefloquine, lumefantrine or sulfadoxine/pyrimethamine. Quinine, along with doxycycline, may be used if artemisinin is not available, even though P. Falciparum has developed resistance to quinine.
If the parasite really is the problem, then why haven’t we determined the cell frequency of the Plasmodium group and zapped them with a higher frequency to terminate them?
Who is at risk of getting malaria?
The World Health Organization reported that:
In 2021, there were an estimated 247 million cases of malaria worldwide.
The estimated number of malaria deaths stood at 619 000 in 2021.
The WHO African Region carries a disproportionately high share of the global malaria burden. In 2021, the region was home to 95% of malaria cases and 96% of malaria deaths. Children under 5 accounted for about 80% of all malaria deaths in the Region.
In 2021, nearly half of the world's population was at risk of malaria. Some population groups are at considerably higher risk of contracting malaria and developing severe disease: infants, children under 5 years of age, pregnant women and patients with HIV/AIDS, as well as people with low immunity moving to intense malaria transmission areas, like migrant workers, mobile populations and travelers.
Can we prevent malaria?
Obvious ways to reduce your risk of being bitten by a female malaria-carrying mosquito are to use insecticide-treated mosquito netting over your sleeping area; wear light coloured, loose-fitting clothes with long sleeves, long pants, socks and clothes that cover exposed skin and head areas; drain any standing water to curtail breeding; spray indoor areas and wear mosquito repellent. Mosquitoes avoid some smells that they do not like and those can be used as a spray or as incense to ward them off: Lemon eucalyptus, Peppermint, Lavender (repellent and healing ointment), Citronella oil (repels and topically helps heal mosquito bites).
Here are some interesting hints for repelling mosquitoes from a pest control company:
#1: Carry a Dryer Sheet in Your Pocket or Rub It on You
Mosquitoes hate the smell of dryer sheets from the chemicals linalool and beta-citronellol. Both of these chemicals work as mosquito repellents and are toxic to other insects like gnats.
#2: Mix a Garlic Water Spray Solution
Mosquitoes despise the smell of garlic. Boil a peeled and crushed garlic clove for 20 minutes and put the water in a spray bottle.
#3: Burn Incense In and Around Your Home
Mosquitoes hate smoke, especially smelly smoke. Burn incense that contains eucalyptus, cloves, and citronella. Burn it inside or outside your home and mosquitoes will avoid you.
#4: Spray Yourself With Bath Oil
Spray bath oil on yourself and cover your skin. Mosquitoes won’t come near you! You can moisturize and repel pests at the same time!
#5: Add Piñon Wood to Your Wood Stack
Piñon wood, like incense, gives off a distinct odor which mosquitoes are not too fond of. Add piñon wood the next time you light up your fire pit and mosquitoes won’t approach.
#7: Apple Cider Vinegar Repellent
Make a spray mixture of apple cider vinegar, citronella, and witch hazel and spray your area.
#8: Anti-Mosquito Garden
Catnip, peppermint, lavender, sage, rosemary, citrosum, lemon balm, and basil growing in your garden are all great at keeping mosquitoes away.
#9: Essential Oil Spray
Make an essential oil spray mixture using oils like thyme, lavender, or peppermint in your concoction. Always dilute with a carrier oil so it will not irritate the skin.
Mosquitos are adapting to attempts to kill them. They are becoming insecticide-resistant; they are avoiding indoor spaces more frequently; and are biting earlier in the afternoon and evening before people go to bed.
In 2021, 35 countries reported fewer than 1000 indigenous cases of the disease. Since 2015, nine countries have been certified malaria-free by the WHO: Maldives, Sri Lanka, Kyrgyzstan, Paraguay , Uzbekistan, Argentina, Algeria, China and El Salvador.
On October 5, 2015, at age 85, Tu Youyou Tu, a Chinese pharmaceutical chemist and malariologist, working at the China Academy of Traditional Chinese Medical Sciences in Beijing, was awarded the Nobel Prize in Medicine for discovering artemisinin and its synthesized form of dihydroartemisinin (from sweet wormwood (Artemisia annua), which has been credited with cutting worldwide malaria deaths in half. She had been working to find a natural herb that fights malaria since 1967!
In studies done with African children, current available vaccines for malaria are only about 40% effective. Vaccine development is ongoing.
Did you know that sniffer dogs can be trained to be 90% effective in telling whether someone has malaria by sniffing their socks? Researchers found that dogs were able to smell malaria in samples of socks worn by children infected with malaria. This could help doctors achieve quicker diagnosis and treatment, especially for children.
https://youtu.be/rrCJ0hc4tzU Here’s a video about it.
Here is an article in The Lancet about the study. Trained dogs identify people with malaria parasites by their odour - The Lancet Infectious Diseases
What did you decide?
Do you think malaria is inflammation caused by a parasite from the Plasmodium group or do you think malaria is a virus? If you think it is a virus, do you think the virus is in the single-celled parasite or in the mosquito’s virome? Or… do you think it is some combination?
Reach out and let us know what you are thinking.
Comments
Post a Comment