Fitter and Drug Resistant Strain of Malaria Parasite Threatens to Rise to Epidemic Proportions

Multidrug resistant strains of P. falciparum, termed malaria superbugs, were recently identified in certain regions in Laos, Thailand and Cambodia. These superbugs have led to failure in treatment rates when treated with malaria medicines against falciparum that include artemisinin combination therapies (ACTs). The study published in the journal The Lancet Infectious Diseases details the P.falciparum lineage that threaten to spread globally, affecting eradication efforts.

Multi-Drug Resistant Strains

There has been an increase in the multi-drug resistant strains of P.falciparum which the authors of the study warn about

• In Cambodia, there is wide spread presence of malaria parasites which are resistant to both piperaquine and artemisinin
• In Northeastern Thailand, Western Cambodia and Southern Laos, there are more virulent multidrug resistant parasites.

Thailand’s Head of Malaria and Deputy Head of the Mahidol Oxford Tropical Medicine Research Unit (MORU) Prof. Arjen Dondorp who is also the lead author of the study said that the scientists were able to identify the emergence of a highly successful multi-drug lineage of the parasite, which was far superior to the other strains and which was now spreading to other areas. The lead author stated that these malarial parasite strains were resistant to even the partner drug piperaquine, resulting in increased failure of treatment with artemisinin combination therapy Dihydroartemisinin-piperaquine. The study was conducted, according to the authors, to re-emphasize the growing trend of resistant strains of malaria and the urgent need to lower their numbers, before malaria becomes untreatable in Asia.

Spread of Resistant Malaria Strain Through India

The scientists involved in the study state that consequent spread of the multi-drug resistant strain of malaria parasite via India to the regions of sub-Saharan Africa could result in a global epidemic, leading to catastrophic effects. There has been a warning provided by the study authors to increase monitoring in the Greater Mekong Sub-region with increased efforts to prevent spread to neighboring regions.

Prof Sir Nicholas White said that the race to eliminate artemisinin resistant malaria is already a losing battle as the resistance to associated anti-malarial drugs has already begun setting in. He further stated that “The consequences of resistance spreading further into India and Africa could be grave if drug resistance is not tackled from a global public health emergency perspective."

Analysis

The scientists analyzed blood samples of patients who were suffering from uncomplicated falciparum malaria and who were infected in Myanmar, Laos, Thailand and Cambodia. The findings of the study were

• The single mutant parasite strain PfKelch13 C580Y had spread across three countries.
• It resulted in replacement of strains that were found to be less resistant to artemisinin combined therapy.
• The strains with the C580Y mutation is not more resistant to artemisinin but is found to be fitter, implying that is transmitted more often and spreads fast.

PfKelch13 C580Y strain of P.Falciparum

Prof. Sir Nicholas White said that the C580Y mutation in P.falciparum was not responsible for the malaria parasite being fitter but other genetic alterations could aid in it being fitter. This has resulted in the evolution of a new lineage of super bugs that are more transmissible and fitter. The senior author stated that the spread of malaria via India and Africa has occured before and the result was the death of millions of people due to the disease. With the spread of drug resistance strains and the lack of effective therapy, it could again be very drastic. There is a concerted effort needed in building collaborative strategies that address the threat in Asia in urgency to prevent a repeat of the earlier epidemic.

The Head of Infection and Immunobiology at Wellcome Trust, Dr. Mike Turner said that there were many hundred who lost their lives every year due to infectious and drug resistant strains, which include malaria. This number could increase to millions by 2050 if corrective measures are not taken.

Careful monitoring of the spread of the disease and improvements in care are necessary for

• Diagnosis
• Treatment
• Prevention

Significance of Malaria

Malaria is a cause of public health concern across many regions in the world with transmission occurring regularly. It is a complex disease and varies in intensity based on epidemiology. The most susceptible population are pregnant women, small children, tourists to malaria prone areas who have not been immunized as they could develop fatal illness.

Malaria Symptoms

The time taken for the symptoms to start is between 7 to 18 days, based on the parasite that causes the infection. In very rare cases, it could take up to a year for the symptoms to show. The initial symptoms are high fever, headache, chills and vomiting. These symptoms could be mild and it may make it difficult to distinguish it as malaria.

However, in certain types of malaria there is a 48 hour fever cycle when there is cold and shivering. There is a period of shivering with the individual feeling cold, followed by high fever and then again sweating and fatigue. The person may also have muscle pain general feeling of tiredness and diarrhea.

There is a very severe form of malaria which is caused by the parasite P.falciarum and without immediate treatment; this infection could become life threatening with difficulty in breathing and organ failure.

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The development of drug resistance has resulted in the spread of the disease to newer regions and also in the re-emergence of the disease in areas where the disease has been eradicated. The severity of the disease and the occurrence of the disease have also been affected due to drug resistance while travel or population movement has resulted in the transfer of these drug resistant malaria strains. There is a highly important need to develop strategies to prevent the spread of these strains of malaria as it could lead to a disease of epidemic proportions.

References:

1. Drug resistance in malaria - (http://www.who.int/csr/resources/publications/drugresist/malaria.pdf)
2. Malaria - Symptoms - (http://www.nhs.uk/Conditions/Malaria/Pages/Symptoms.aspx)

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Source-Medindia