With the onset of the monsoon season earlier this month in most parts of India, the number of reported Dengue fever cases has gone up significantly. While stagnant water and augmented mosquito populations are obvious causes for this prevalent increase, what also plays a major role is the population’s lack of awareness about preventive and protective measures. In a country where official reports state that almost 20000 people are affected by this disease annually, this ignorance on the public’s part comes at a hefty price.
Apart from the estimated US$ 1.11 billion economic burden it is expected to cause, lack of understanding about this mosquito borne disease is also rendering the public health system unprepared and inadequately equipped to deal with the large number of patients that are checking in with this disease everyday.
This disease is viral in origin, with four different strains of the Dengue virus being responsible for causing infection through the bite of the mosquito Aedes Aegypti.
However lack of extensive data pertaining to the immune responses generated by the Indian population against this virus drove researchers at All India Institute of Medical Sciences (AIIMS), Translational Health Science and Technology Institute (THSTI),Institute of Genomics and Integrative Biology (IGIB) and International Centre for Genetic Engineering and Biotechnology (ICGEB) to study this disease better.
Dr.Guruprasad Medigeshi, the lead author of this study, recently published in the journal PLOS Neglected Tropical Diseases, stated, “We pursued this study since there is no extensive characterisation of dengue versus immune response in the Indian population, be it adults or children. The intuition was to look at the paediatric infection in India as the young are most susceptible. We investigated the factors that are either responsible for, or occur due to severe infection.”
About the study
According to the WHO, the severity of Dengue fever can be categorized into three distinct types- Severe Dengue (SD),Dengue Illness (DI) and Dengue with Warning Signs (DW). For this study, blood samples were collected from a cohort of 97 children suffering from any of the three classifications of this disease.Sixty percent of this population was found to be suffering from secondary infections rather than primary ones and Serotype 2 DENV was identified in most of the samples.
While studying the factors impacting viraemia (presence of virus in blood) in the given samples, it was found that disease severity had no direct linkage the viral load.
Also, the decrease in platelet count, which is considered to be one of the most recognized symptoms of this disease, seemed to be directly proportional to the increase of viral load in the blood. Researchers attribute this finding to the assumption that Dengue virus probably acts by altering or hampering the function of the host organism’s platelets.
Interleukins and Interferons are cytokines that usually help in enhancing immune responses during infections. The role that these small proteins played during the course of the Dengue virus were also studied and the level of interferons in the blood were found to dictate a person’s level of susceptibility while contracting the disease.
According to Dr.Medigeshi,”Dengue severity may either cause interferon levels to drop, or people with low interferon levels might be a susceptible population to dengue infections.”
This is probably why interferon therapy was identified as a recovery measure in both the cases.
Using bioinformatics, markers of dengue disease severity and recovery were also identified and analysed .
“Through a systematic measurement of baseline factors, pre-disposability to dengue can be detected and target population identified very early in infection,” claimed Medigeshi.
Tackling this disease by studying it at the molecular level is bound to aid public health personnel and medical professionals in a significant way. Diagnosing and treating Dengue will become a relatively easier task if efforts are made to understand the virus and its subsequent effects better.
Studies like these have the possibility of translating into larger outcomes like better healthcare infrastructure and fewer number of reported Dengue cases per year.
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