History’s Seven Deadliest Plagues

Link Between Malaria 'headache' And Climate Crisis

 A business man overwhelmed by stress and headache. [Getty Images]

A common question doctors ask when you display some symptoms such as fever is whether you have recently travelled to malaria hot spots.

Different countries' efforts, combined with help from non-profit organisations have helped reduce cases of malaria, and resultant deaths. In Kenya, statistics show that 2011 (at 11.12 million cases) and 2018 (with 10.88 million) were the years the disease hit worst between 2010 and 2020.

Interventions have included free distribution of mosquito nets, spraying, minimising potential breeding places such as stagnant water and awareness creation. Malaria deaths have significantly been brought under control.

Yet mosquitoes become cleverer, with such suggestions that they no longer wait for you in the bedroom, but start work earlier, before dark. Some mosquitoes have become resistant to some insecticides, beside several other behaviour changes. Experts say temperatures between 22 degrees Celsius and 34 degrees Celsius are conducive for development of a mosquito larva to a fully functional adult that can spread malaria. But there are also suggestions the insects rest in cooler areas, where they would seldom venture before.

The earth has been warming gradually as a result of human action involving use of fossil fuels to industrialise. Models show increased warming in future, despite efforts and pledges by nations and corporates to try to tame it and reduce disasters. The global warming has not only endangered or pushed certain animal and plant species to extinction, but also caused many to move to newer ground. They include malaria transmitting mosquitoes.

If a recent study published in 'Biology Letters' is anything to go by, mosquitoes are venturing in more environments. The study, from analysis of data between 1898 to 2016, shows that malaria transmitting mosquitoes have moved an average 4.7km farther from the Equator in the last 100 years alone.

Other studies have also attempted to link malarial spread to changes in temperatures. For instance, "The relationship between rising temperatures and malaria incidence in Hainan, China, from 1984 to 2010: a longitudinal cohort study", published in the 'Science Direct', established links between climate conditions and malaria transmission in different altitudes. While researchers dig deeper to establish link between climate change and malaria, this is what the future may just look like.

It may mean more populations that have historically not been prepared to handle malaria becoming more vulnerable. It may mean more resources set aside for research, awareness creation, expansion of health facilities and prevention of the disease's spread. The disease's spread to unexpected newer ground may also hinder its elimination. What is for sure, however, is that as the earth becomes warmer, in some places, more mosquitoes are born because it happens faster. If the mosquitoes breed faster, they will need new ground, and may move to areas where they were not seen. More people (and maybe birds and some animals) will be exposed to mosquito bites. The more the bitten, the higher the supplies for mosquitoes transmitting malaria. More mothers will risk spreading diseases during child birth.

Some outlined mosquito behaviours in recent studies are adequate cause for worry, and should necessitate climate action, as this ceases to be a health-alone problem. Even if for prevention purposes alone, and while the disease is dealt with, efforts to tame global warming must be boosted. If the initial findings in the studies hold, then the worst effects of climate change may cease to be calamities such as drought and floods alone. Diseases will be next big climate change emergency.

Antibody Discovery Improves Malaria Treatment

Malaria is a life-threatening disease that is transferred by mosquito bites. Interestingly, a specific type of mosquito can carry the disease. The transfer of the parasite to humans travels to the liver where it can lie dormant for weeks before infecting red blood cells. Once the infection spreads to the blood, patients start having symptoms including fever, headache, chills, fatigue, vomiting, nausea, body aches, and yellow skin. At this point a mosquito can bite that infected person and further transmit the disease.

Healthcare professionals consider malaria a medical emergency that require immediate attention. Chloroquine is a common treatment given to malaria patients, but many others are available for those that are chloroquine resistant. Malaria is most common in Africa, but can also occur in Central and South America, as well as Southeast Asia. To prevent malaria, individuals take precautions to avoid mosquito bite risk. Therefore, mosquito nets and repellent help reduce risk. Individuals can also wear protective clothing and use vaporizers.

In addition to mosquito control strategies, scientists are developing vaccines and other drug treatments to more effectively treat malaria. This is particularly important for malaria strains that are drug-resistant. Unfortunately, the biological mechanism of malaria is still not completely understood, and scientists are working to learn more about this parasite to provide enhanced treatments.

A recent paper in Nature, by Dr. Thomas Lavstsen and others, discovered antibodies that can recognize, and target proteins associated with malaria. This is a major breakthrough in the field of malaria treatment. Specifically, this paves the way for improved malaria vaccines and anti-malaria drugs. Lavsten is a professor within the Department of Immunology and Microbiology at the University of Copenhagen. His work focuses on malaria life cycle, progression, and malaria vaccine development. His recent work focuses on malaria's interaction with the immune system and how our body responds to treatments.

Progressive or severe malaria is caused by a parasite known as Plasmodium falciparum, which infects red blood cells. As a result, the red blood cells stick to blood vessels and cause disruption of blood flow. Clogged blood vessels can lead to fatal injury, especially if it occurs in the brain. The blocked vessels are caused by a family of malaria-related proteins which allow the red blood cells to stick to the blood vessel walls. Researchers wanted to understand ways to target these surface proteins to eliminate blood vessel obstruction. In collaboration with other research groups, Lavsten and his team found an antibody that targets these proteins and avoids the development of blood vessel clotting.

The team developed a technique to grow human blood vessels in a dish and used this to test whether the antibody had an effect on malaria infected blood. The team could not use mouse models because mouse biology against malaria is too different and would not have translated well to humans. Therefore, researchers treated malaria-infected blood with the suspected antibody and found a significant decrease in blood vessel occlusion.

Lavsten and others for the first time discovered an antibody that can target a wide array of malaria surface proteins to avoid blood clots. This discovery has major implications on the development of malaria vaccines and has the potential to reduce risk in children who have low levels of these specific antibodies. Overall, this research has the potential to improve current malaria treatment and increase patient survival.

Paper, Nature, Thomas Lavstsen, University of Copenhagen

Scientists Find A New 'cure' For Malaria; It Is Delivered By A Mosquito Bite!

Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. It is preventable and curable. There are 5 parasite species that cause malaria in humans, and 2 of these species – Plasmodium falciparum and Plasmodium vivax – pose the greatest threat.As per World Health Organisation, WHO, nearly half of the world's population was at risk of malaria in 2022. While sub-Saharan Africa carries a disproportionately high share of the global malaria burden, the WHO regions of South-East Asia, Eastern Mediterranean, Western Pacific, and the Americas also report significant numbers of cases and deaths.

How does one 'catch' Malaria? Malaria mostly spreads to people through the bites of some infected female Anopheles mosquitoes. Blood transfusion and contaminated needles may also transmit malaria. The first symptoms may be mild, similar to many febrile illnesses, and difficulty to recognize as malaria. Left untreated, P. Falciparum malaria can progress to severe illness and death within 24 hours.The infection is caused by a parasite and does not spread from person to person. Symptoms can be mild or life-threatening. Mild symptoms are fever, chills and headache. Severe symptoms include fatigue, confusion, seizures, and difficulty breathing. Infants, children under 5 years, pregnant women, travellers and people with HIV or AIDS are at higher risk of severe infection. Malaria can be prevented by avoiding mosquito bites and with medicines. Treatments can stop mild cases from getting worse.Scientists recently have developed a new vaccination strategy for malaria, which is boosting immunity through bites from mosquitoes carrying a genetically engineered version of the parasite that causes malaria. In a trial, the new approach reduced participants' susceptibility to malaria, potentially paving the way for more effective ways to stop the disease.The study published in 'The New England Journal of Medicine' recently, exposed participants to bites from mosquitoes that had a modified version of the Plasmodium falciparum parasite, which causes malaria. In humans, the parasites travel to the liver and then infect red blood cells. The parasites were engineered to stop developing shortly after delivery into a human. Nearly 90% of participants exposed to the modified parasites avoided contracting the disease after being bitten by malaria mosquitoes.Julius Hafalla, an immunologist at the London School of Hygiene & Tropical Medicine, said, "These findings represent a significant step forward in malaria vaccine development. The ongoing global malaria burden makes the development of more effective vaccines a critical priority."Symptoms: Symptoms usually appear 10–15 days after the bite of an infected mosquito. Early symptoms include fever, headache, and chills. Severe symptoms include fatigue, confusion, seizures, and difficulty breathing.Transmission: Malaria is spread by the bite of infected female Anopheles mosquitoes. It can also be transmitted through blood transfusions and contaminated needles.Diagnosis: A doctor can suspect malaria based on your travel history, symptoms, and physical exam. To confirm, they may order laboratory tests to see if the parasite is in your blood.Treatment: Malaria is treatable, and starting treatment as soon as possible can often prevent severe illness and death. Chloroquine is often used as an anti-malarial medicine, but there are also treatments for chloroquine-resistant infections.

Vaccines for Malaria: So far, there are two approved malaria vaccines. Both aim to provide long-term immunity by producing antibodies that block malaria parasites from infecting liver cells, as well as targeting breakthrough infections. However, the vaccines are only about 75% effective, and require booster shots. Hence, immunologists are continuing to explore alternative strategies to battle the disease.One of those approaches is using genetically modified parasites. The research team had previously conducted a trial to examine the effectiveness of a modified malaria parasite, called GA1, designed to stop developing about 24 hours after infection in humans. But the GA1 parasite protected only a few participants against malaria, leading the team to engineer a second parasite, GA2. GA2 is designed to stop developing about six days post-infection, during the crucial period where the parasites replicate in human liver cells.The researchers tested whether exposure to GA1 or GA2 could help humans develop immunity to malaria. They exposed participants to bites from 50 mosquitoes; 10 participants received bites from mosquitoes infected with GA1 parasites, and 10 were bitten by those with GA2 parasites. Three weeks later, they exposed participants to malaria-carrying mosquitoes. Just before exposure to these mosquitoes, both sets of participants had higher levels of antibodies than before. One of eight (13%) participants bitten by GA1 parasites didn't contract malaria compared with 89% in the GA2 group. Other than the itching associated with mosquito bites, side effects were limited.The researchers are now keen to replicate their results in a larger trial.

Study reveals how mosquitoes possess bizarre sense of smell

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