Five years ago, I traveled to Karachi, Pakistan. It was a hot and humid summer, and the mosquitoes were loving it. The other thing they seemed to love (a lot) was me. I have to admit, I’m a fun and loveable person, and I like attention, but getting attention from mosquitoes is not my cup of tea. That summer I counted a high of 64 mosquito bites at a single time. I didn’t understand why I was the only one who used to get bitten. “Thumara khoon bohat meeta hai” was what people would say to me. My blood is very sweet? What does that even mean? Using that logic, I started taking citrusy vitamin C supplements to make my blood less sweet. I’m pretty sure that didn’t work. I had finally gotten bit by a malaria-carrying mosquito, and I spent a bit of my lovely vacation getting chills and fevers, constantly turning the AC on and off. Thank goodness my uncle was a doctor and gave me several anti-malarial drugs he had in his medicine cabinet.
Currently, there are several drugs on the market worldwide that help fight against malaria, and reduce its symptoms. There are four types of malaria: Plasmodium (P) falciparum, P. vivax, P. ovale, and P. malariae. Plasmodium is a parasite spread by female anopheline mosquitos. Once a malaria-carrying mosquito bites its prey (i.e. me), the parasite is carried to the liver and there it reproduces by multiple fission until the liver cells begin to burst. These parasites are then released into the bloodstream, and infect the red blood cells. Quinine, the first successful treatment of malaria, effectively targets and kills the parasites that have been damaging the red blood cells. Other drugs that are used to treat or prevent malaria are chloroquine, mefloquine, and quinidine. 1 Unfortunately, P. falciparum is resistant to these drugs, and only IV quinine (not available in the U.S.) is used to treat this type of malaria.
Since different strains of Plasmodium are becoming increasingly resistant to anti-malarial drugs, experts in malaria research have started to find new ways to treat and control malaria. For example, at the Johns Hopkins Malaria Research Institute, Dr. Ernesto Freire is working on targeting plasmepsin, a parasite enzyme that is responsible for the degradation of the hemoglobin. He has successfully developed plasmepsin inhibitors that have effectively destroyed the parasites present in infected red blood cells.2 On the other coast of the country, Dr. Stefan Kappe at the Malaria Clinical Trials Center of Seattle BioMed has developed a genetically attenuated parasite (GAP) malaria vaccine that has shown to be 100% effective in mice. The entire malaria parasite is altered and weakened by deleting two key genes. A similar approach of weakening a disease-causing organism has been used for smallpox and polio vaccines. This is the first study that weakens a whole human parasite to create a vaccine that improves immunity to malaria. 3
According to the World Health Organization, there are about 250 million malaria cases and nearly one million deaths each year due to the severe symptoms and untreatable nature of certain stages of malaria.4 There are currently several brand name anti-malarial drugs on the market, but due to malaria parasites becoming increasingly resistant, research around the world has been focused on developing new strategies to fight this horrible disease. To read more about the current research out there, you can visit the following websites:
The Bill and Melinda Gates Foundation: http://www.gatesfoundation.org/topics/Pages/malaria.aspx
PATH Malaria Vaccine Initiatives: http://www.malariavaccine.org/
Roll Back Malaria Partnership: http://www.rollbackmalaria.org/
Johns Hopkins Malaria Research Institute http://malaria.jhsph.edu/
Malaria Clinical Trials Center| Seattle BioMed http://www.seattlebiomed.org/trials
Also, if you travel anywhere that is not malaria-free (http://www.rollbackmalaria.org/endemiccountries.html) and a doctor with a cabinet full of anti-malarial drugs will not be there with you, then go to this website: http://www.cdc.gov/malaria/travelers/drugs.html to learn which anti-malarial drugs to take with you.
”WHO | Malaria.” Media Centre. World Health Organization, n.d. Web. 21 Feb. 2011. <www.who.int/mediacentre/factsheets/fs094/en/>.
2 Miura, T., Hidaka, K., Uemura, T., Freire, E., et al. (2010). Improvement of both plasmepsin inhibitory activity and antimalarial activity by 2- aminoethylamino substitution. Bioorganic & Medicinal Chemistry Letters, 20(16), 4836-4839.
3 VanBuskirk KM, O’Neill MT, De La Vega P, Kappe S, et al. Preerythrocytic, live- attenuated Plasmodium falciparum vaccine candidates by design. Proc Natl Acad Sci USA 2009; 106: 13004–13009.
4 “What is Malaria ?.” WHO SEAR, Regional Health Situation, and World AIDS Day, Health Report . N.p., n.d. Web. 23 Feb. 2011. <http://www.searo.who.int/EN/Section10/Section21/Section334.htm>.