Humanity faced thousands of pathogens — such as bacteria, viruses, parasites, or fungi — that caused infectious diseases during its history. According to the World Health Organization, these diseases can be spread, directly or indirectly, from one person to another.  Pathogens are always changing through evolution and scientists are continually studying new ways to diagnose and treat them. Therefore, Ebola, Malaria, and Covid-19 are some infectious diseases that stood out in the last years for their impact around the world.

Figure-The different types of coronaviruses.

Today we are fighting against a pandemic caused by SARS-CoV-2, and many challenges have emerged since 2019. Multiple studies have been made to understand how this virus works, spreads and causes. Therapies were developed and pathogenic mechanisms in different stages of COVID-19 were clarified.

• Pathobiology overview

In the first stage, known as asymptomatic (1-2 days infected), the Sars-Cov-2 virus binds to epithelial cells, ciliated cells are primarily infected,  in the nasal cavity and start replicating. In the next few days, it starts to propagate and migrate into the respiratory tract, so a robust innate response is triggered.  If the patient progresses to the third stage, the virus reaches the gas exchange units of the lung and infects alveolar type II cells, then numerous viral particles are released and cells begin to die¹.  

The pandemic affected more than 200 countries² and unfortunately impacted public health around the world with the dissemination of other diseases too, one of them being malaria, because of disruptions in the provision of prevention, diagnosis, and treatment during this period.

The gray blocks represent the number of COVID-19 cases diagnosed per surveyed facilities (right Y-axis). The line graph describes service delivery for the same period in 2020 (left Y-axis).

Figure: The data from facilities in this snapshot indicate that surveillance activities monitoring the spread of cases in countries, malaria diagnosis, and malaria treatment have all fallen in 2020 relative to 2019. Source: The Global Fund. 

Although we are talking about the present, Malaria has been occurring since ancient history with writings and artifacts testifying to it, for example, its antigen detected in Egyptian remains from 3200 and 1304 BC or Indian writings of the Vedic period, that happened between 1500 and 800 BC³. 

This infection is caused by a parasite, named Plasmodium, which is transmitted through the bites of infected female Anopheles mosquitoes.  The sporozoites enter hepatocytes and a few weeks later are found in the bloodstream. In the merozoite stage, they enter erythrocytes, develop into trophozoites and then schizonts. When the infected blood cells break down, release merozoite, and a new cycle begins.

Plasmodium has several strategies to contaminate the human body by repeated cycles of growth.  Its multiplication causes fever, chills, sweating, feeling generally unwell, and sometimes diarrhea, abdominal pain, difficulty breathing, confusion, and seizures.  The expression of Malaria is influenced not only by the parasite but the host too, as demonstrated in its exacerbation during pregnancy. Even though this infectious disease is preventable and curable,  just in 2020, 241 million cases ensued all over the map, generating around 627 000 deaths⁴. 

Furthermore, Ebola Virus Disease (EVD), the most studied in the Filoviridae family, had its most complex outbreak between 2014 and 2016 in West Africa since its discovery in 1976. The disease is of great concern for the fatality rate, around 50%⁵. Initially, this negative-sense RNA virus is transmitted to people from wild animals and then spreads from one person to another through direct contact —  through eyes, nose, mouth, or a wound — with body fluids such as excrement, sweat, semen, or materials contaminated. Several symptoms are shown, such as fever, malaise, myalgia, vomit, diarrhea, even bleeding abnormalities, and these manifestations cause considerable fluid loss. 

What makes this virus so dangerous? 

Well, one of the factors that contribute to its pathogenicity is an envelope glycoprotein spike, which is expressed on the cell surface and is incorporated into the virion to drive viral attachment and membrane fusion.  Also, the process to access the host cell is complex, marked by a multi-facet process and various studies are developed to understand better the macropinocytosis-like mechanism related to the cellular entry.

Because of the high incidence of these two challenges — Ebola and Malaria — they were also studied together, to understand how Plasmodium spp. and Ebolavirus (EBOV) interact for possible future outbreaks, especially in African countries⁶. The use of bioinformatics for this kind of study is very useful, through the R software, for example, it is possible to conduct a meta-analysis with the purpose of identifying gaps, understanding the prevalence of coinfection, the effect, the immune response, and the mortality. 

Bioinformatics is an integral part of modern-day research of infectious diseases, this happens due to the fact that most sequences are originated in this field, and omics provide an amount of information necessary to develop large-scale studies that would not have been possible using the classical research approach⁷. In general, the ‘omics’ has been contributing to the understanding of infection diseases, by how diseases develop over time, how they happen, the pathogens spread and resistance,  how they interact with the host, and also the host immune response. 

Are you interested in learning more about fighting infectious diseases through bioinformatics?

Omics Logic will conduct a FREE Webinar on “Bioinformatics for Infectious Diseases” to present a review of the current priorities in virology research and challenges at the frontiers of this rapidly accelerating field.

Date - February 3, 2022

Time - 3 PM GMT || 9 AM CST

Don’t miss this opportunity!

Click on the link below and check it out!

https://edu.omicslogic.com/bioinformatics-for-infectious-diseases-2022

References:

• Mason, R. J. (2020). Pathogenesis of COVID-19 from a cell biology perspective. European Respiratory Journal, 55(4).

• Platto, S., Xue, T. & Carafoli, E. COVID19: an announced pandemic. Cell Death Dis 11, 799 (2020). https://doi.org/10.1038/s41419-020-02995-9

• Gelband, H., Panosian, C. B., & Arrow, K. J. (Eds.). (2004). Saving lives, buying time: economics of malaria drugs in an age of resistance.

•  World Health Organization. (2021). World malaria report 2021.

• Edwards, H. M., Counihan, H., Bonnington, C., Achan, J., Hamade, P., & Tibenderana, J. K. (2021). The impact of malaria coinfection on Ebola virus disease outcomes: A systematic review and meta-analysis. PloS one, 16(5), e0251101. https://doi.org/10.1371/journal.pone.0251101

• World Health Organization. Ebola Virus Disease. 2021. Available: https://www.who.int/news-room/fact-sheets/detail/ebola-virus-disease.

• Paszkiewicz, K. H., & van der Giezen, M. (2011). Omics, Bioinformatics, and Infectious Disease Research. In Genetics and Evolution of Infectious Disease (pp. 523-539). Elsevier.