A Comprehensive Guide to Malaria

A tiny, inconspicuous insect can cause a cascade of detrimental, possibly deadly, effects within our bodies. Our immune systems tirelessly fight the aggressive parasite Plasmodium when infected (Talapko et al., 2019). At first glance, the infamous parasite responsible for the disease malaria may seem to have been eradicated, as it is no longer a widespread, pertinent problem in the United States; however, malaria is far from abolished and is clearly expanding in its scope to tropical countries in Africa and Asia. Living in the United States, it is easy to overlook major global medical problems that do not directly affect us. But the shocking fact is that malaria is on the rise: the world malaria report from November 2020 claims that there were 229 million cases of malaria in 2019, which is a significant increase from the 228 million cases in 2018 (World Health Organization, 2020). The death toll has slightly decreased, with 409,000 deaths in 2019 and 411,000 deaths in 2018, but nonetheless, the number of cases is increasing, despite the availability of antimalarial drugs. So how prevalent is it really? Welcome to my guide to understanding malaria.

The first records of malaria trace back to 2700 BC, specifically in ancient Chinese medical documents (Talapko et al., 2019). Approximately twelve hundred years later, there is evidence of malaria in the Ebers Papyrus–a compilation of medical knowledge from ancient Egypt, circa 1550 BC (Talapko et al., 2019).  Interestingly, researchers discovered Plasmodium falciparum, one of the deadliest parasites associated with malaria, in Eygptian mummy tissue samples dating back to Pharaonic times (An interview with Dr. Magda Azab, 2013). Experts concluded that the probable reason for the malaria endemicity in Egypt is linked to the Nile river flooding, which created an ideal breeding ground for mosquitoes that can carry the parasite.

Malaria played a critical role in European history, as it greatly affected Rome during the first century AD. Historians suggest that the disease originated from the Nile river, traveling to the Mediterrean, next spreading eastward to the Fertile Crescent, finally making its way to Greece. Traders from Greece unknowingly carried malaria as they journeyed to Italy, transferring it to Roman soldiers who later brought it to England and Denmark (Arrow, 2004). Extensive human interaction ultimately prompted the expedited spread of malaria; over the next two thousand years, malaria flourished in areas consisting of crowded settlements, causing many to fall ill. In 79 AD, the malaria epidemic ravaged farmers’ marshy croplands, prompting many farmers to abandon their homes (Arrow, 2004). 

Slaves from Africa, who were initially protected from malaria because of genetic predispositions such as sickle cell anemia, introduced it to the New World, where malaria devastated European settlers and Native Americans alike (Arrow, 2004). Later, this disease plagued Civil War soldiers, moved towards California through the Gold Rush, spreading throughout the United States and greatly affecting the country’s physical well-being and economic life. The spread of malaria encountered a hiatus until World War II, when it worsened tremendously. Thus, the United States established the Centers for Disease Control and Prevention to combat malaria (Arrow, 2004). 

But more than any other region, sub-Saharan Africa continues to face immeasurable damage due to malaria, as its climate, wild-life, and poverty present the perfect conditions for malaria breeding sites: 80-90% of global malaria cases originate in Africa (Arrow, 2004). At a biological level, African people who are carriers of the sickle cell gene have  protection against malaria–a compelling insight into this disease. 

It is essential to understand the progression of malaria, as it is not a typical virus or bacterial disease. Rather, it is caused by a parasite transmitted through female mosquito bites, specifically the marsh mosquito (Talapko et al., 2019). The parasitic Plasmodium sporozoite is transmitted into the capillary of the host and migrates to the liver (Schantz-Dunn & Nour, 2009). The sporozite–a spore-like elongated cell–multiplies in the liver and exits the bloodstream as a merozoite, invading the erythrocytes, or red blood cells, and causing widespread infection (Schantz-Dunn & Nour, 2009). 

Malaria can be classified into two categories: uncomplicated and severe. Uncomplicated malaria has symptoms ranging from a cold sensation, shivering, fever, headaches, sweating, and possible seizures, while severe malaria consists of organ damage and blood abnormalities, such as anemia, pulmonary edema, renal failure, and cardiovascular collapse (Schantz-Dunn & Nour, 2009). Generally, symptoms start 10 days to 4 weeks after infection, but surprisingly, some parasitic infections can live dormantly within the host’s liver for months, even years, infecting the host much later after the initial mosquito bite (Centers for Disease Control and Prevention, n.d.). Pregnant women are three times more likely than non-pregnant individuals to contract other diseases due to malaria (Schantz-Dunn & Nour, 2009). The infection of malaria may lead to a higher risk of anemia and placental burden–a dangerous consequence for developing fetuses. Furthermore, erythrocytes affected by malaria can cause folic acid deficiency. Issues related to anemia creates a higher risk for long-term medical problems such as congestive heart failure and hemorrhage during delivery (Schantz-Dunn & Nour, 2009).

The mortality rate of malaria ranges from 0.3-2.2% globally, but can be between 11-30% in areas of tropical climate, especially in Africa and Asia (Talapko et al., 2019). Indeed, climate change and malaria may be related: the United Nations states that an increase in temperature, rainfall, and humidity may contribute to an increase in malaria mosquito proliferation at higher altitudes (World Health Organization, 2020). Additionally, malaria is more common at lower altitudes, but the rise in temperature can speed up the growth cycle of the malaria parasite. Other links to malaria and climate change include the El Niño cycle, which is when the surface of water warms and causes more effective transmission of diseases via mosquitoes (World Health Organization, 2020). Overall, wet, tropical environments are proven to be optimal environments for mosquitoes to thrive in, so more rainfall, even in dry environments, can contribute to the increase in malaria cases. 

As such, it is important to raise awareness for the consequences of climate change, direct and indirect. The United Nations suggests that global travel to countries with higher cases of malaria may unintentionally bring back the parasite to the visitor's home country. The geographic region where a person lives greatly affects one’s immunity to malaria; for instance, living in the United States decreases one’s immunity (Centers for Disease Control and Prevention, n.d.). In countries where malaria is common, there are more public health protocols to control malaria, but other countries likely do not have the same precautions (World Health Organization, 2020). 

Throughout history, there have been numerous antimalarial drugs, constantly evolving and being fine-tuned. The first chemically effective treatment for malaria was Quinine in 1820: this drug was isolated from cinchona tree bark (Tse et al., 2019). However, resistance for this drug developed in the 1980's. Other antimalarial drugs from the past include Mepacrine, Chloroquine, Mefloquine, and Halofantrine. In the present day, the World Health Organization lists 14 medications for malaria, the most effective being artemisinin-based combinations (Tse et al., 2019). Artemisinin was first isolated from a herb traditionally used in Chinese medicine called Artemisia annua. This impressive discovery made in 1971 earned Tu Youyou the Nobel Peace Prize in Physiology and Medicine. In the near future, researchers will attempt to use existing drugs in combination with others to create a new, more effective antimalarial drug that can fight resistance (Tse et al., 2019). 

Moreover, Brian Gitta, a Ugandan inventor, is an example of someone taking strides towards combating malaria. As someone who has experienced malaria multiple times throughout his life, Gitta has dedicated his career to developing a new method of diagnosing malaria that uses light scattering and magnetism techniques to detect differences between normal blood cells and blood cells infected with malaria (Thomson, 2019).

Malaria, a dangerous, parasitic disease, continues to exist today, despite available treatment. Many questions continue to arise, particularly in wake of the increase in malaria diagnosis. With the changing environments, interconnected traveling, and evolving world, it is essential to pay close attention to public health issues in order to prevent a worldwide crisis. Innovative research on antimalarial drugs and diagnosis tools are the first step. The overall takeaway from this guide to malaria is that this disease is not eradicated; rather, on a global level, it is still alive and ominously thriving today, more relevant than ever before. 

References 

Arrow, K. J. (2004). Saving Lives, Buying Time: Economics of Malaria Drugs in an Age of Resistance. https://www.ncbi.nlm.nih.gov/books/NBK215638/#:~:text=Many%20historians%20speculate%20that%20falciparum,abandon%20their%20fields%20and%20villages

Centers for Disease Control and Prevention. (n.d.). The Disease. CDC. https://www.cdc.gov/malaria/about/faqs.html#:~:text=Malaria%20may%20cause%20anemia%20and,confusion%2C%20coma%2C%20and%20death

Fernando, S.D., & United Nations. (n.d.). Climate Change and Malaria - A Complex Relationship. UN Chronicle. https://www.un.org/en/chronicle/article/climate-change-and-malaria-complex-relationship

An interview with Dr. Magda Azab. (2013). Tropical parasitology, 3(2), 170–174. https://doi.org/10.4103/2229-5070.122153

Talapko, J., Škrlec, I., Alebić, T., Jukić, M., & Včev, A. (2019). Malaria: The Past and the Present. Microorganisms, 7(6), 179. https://doi.org/10.3390/microorganisms7060179

Schantz-Dunn, J., & Nour, N. M. (2009). Malaria and pregnancy: a global health perspective. Reviews in obstetrics & gynecology, 2(3), 186–192.

Thomson, H. (2019, August 21). Why are people still dying of malaria when we have treatment? NewScientist. https://www.newscientist.com/article/mg24332440-900-why-are-people-still-dying-of-malaria-when-we-have-a-treatment/

Tse, E. G., Korsik, M., & Todd, M. H. (2019, March 22). The past, present and future of anti-malarial medicines. Malaria Journal.

World Health Organization. (2020, November 30). Malaria. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/malaria#:~:text=According%20to%20the%20latest%20World,411%20000%20deaths%20in%202018