As we continue to become globalized and more connected with people from across the world, we also face the threat of diseases that were once localized to particular regions. Diseases that were once found in tropical regions are now being found in the United States.
There are many treatments that we can take to help prevent infection and protect us as we travel, but problems still arise as the climate continues to change and as animals begin to adapt to new environments. The threats slowly move from localized to globalized. One such threat is malaria.
Malaria is a parasitic disease caused by the parasite in the Plasmodium genus and is spread by bites from female Anopheles mosquitoes. After being bitten, it takes 10-15 for any symptoms to appear. Initially, they are mild fevers, chills, and headaches. However, after 24 hours it becomes more severe and the chances of dying escalate if not treated. In epidemic regions, individuals can develop partial immunity against malaria after repeated exposure to it. Individuals with sickle cell disease also have some immunity against malaria because the parasites cannot use the sickled blood cells to hurt their hosts.
According to the World Health Organization (WHO), there were 212 million people in 2015 living with malaria. Of the 212 million infected, 90% of them are in Africa and the remainder is in the Mediterranean and Southeast Asia regions. While this may seem like a lot, because it is, the trends do show that there is a decrease in malaria infection as new malaria cases fell by 21% in 2015 and mortality rates fell by 29%. These decreases represent the many treatment options and preventative measures that have been introduced into the affected regions, but they all face a new threat of their own – resistance.
The sweet wormwood plant produces a compound called artemisinin, which is isolated and used in various forms and derivatives as the first line of defense against malaria. The compound is able to reduce the number of parasites in the blood of the infected, helping to weaken the disease effects. It is used in great numbers, 311 million courses of artemisinin treatments in 2015, but its time may be running out.
By March 2017, artemisinin resistance in the parasites was found in Cambodia, the Lao People’s Democratic Republic, Myanmar, Thailand and Viet Nam. Now, because of current treatment options, patients were still able to recover in most cases from malarial infections. However, WHO has found that some P. falciparum was found to be completely resistant to almost all anti-malaria treatments along the Cambodian-Thailand border. They also anticipate that the resistance will most likely spread across that region and potentially enter Africa, which would put to risk that 90% of malarial patients.
The resistance developed and was spread because of inadequate malarial treatment policies and centers as well as patients being unable to complete their treatment courses. One of the main contributors to resistance was the wide availability of over the counter anti-malarial drugs and their substandard derivatives. This widespread and use of the drugs lead to high exposure to the parasites, which would result in increased chances of resistance developing. This is a common theme that occurs in other drug resistance cases: a large amount of drug that is put to use without medical need correlates to an increased resistance.
Besides the drug resistance, malaria is also becoming resistant to the insecticides that are used to treat it. According to WHO, 60 of the 73 countries that use insecticides have found that mosquitoes have found at least 1 class of insecticides.
In a recently published article, Mallika Imwong and her team identified the mutation in P. falciparum ( C580Y) that resulted in its resistance to piperaquine, an antimalarial drug. Previously, another mutation, Kelch 13, was identified in 2013 as associated with drug resistance in the parasites. While the mechanisms of how these mutations work will not be covered here, they do serve a useful role. WHO and other researchers used Kelch 13 to monitor the geographic distribution of drug resistance and find areas that are at risk of developing resistance as well as areas in dire need of other treatment options.
For the five countries that resistance has been found in, it is important to begin extensive preventative measures to ensure that these drug-resistant parasites do now spread any further. The WHO has launched an emergency effort to scale up malaria intervention efforts and containment plans. It becomes important to prevent the spread of commonly used antimalarial drugs, to further prevent any more resistance from popping up.
Containment plans and interventions are only the first plans and should not be the only plans. Drug resistance is appearing in numerous diseases besides malaria and current treatments are losing out to the resistance. This means that research must continue into other ways to treat drug-resistant malaria as well as other diseases. Just as stronger and novel antibiotics are being created to address concerns about HIV, MRSA, and other antibiotic-resistant bacteria, something stronger must be made to combat malaria.
This has become a race to the finish line as public health officials, researchers, and governments race against the spread of drug-resistant malaria. Besides artemisinin, quinine is also facing drug-resistance as efforts to use it against malaria continues. According to Michael Chew, a member of the Wellcome Trust medical research charity, deaths from drug-resistant diseases, including malaria, could rise from about 700,000 now to millions in 2050 if nothing is done to prevent the spread of drug resistance.
There are a lot of factors that researchers must face in order to deal with drug-resistance like the tremendous amount of money that is needed, the cooperation of different organizations and governments, and cooperation from the people. While a difficult task, it is feasible. With technologies like CRISPR, allowing up to begin specific genetic modifications, and efforts to create sterile mosquitoes or mosquitoes that are incompatible with the parasites, the future is not so dim as one might think.
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