Reports of numerous infectious disease outbreaks have become a regular occurrence today. From remote jungles to bustling cities, these microscopic invaders dominate headlines raising alarms and challenging our global health systems.
According to the World Health Organization (WHO) report, ‘an estimated 80% of the world’s population is at risk of one or more vector-borne diseases. Mosquitoes, flies, bugs and other vectors transmit viruses, parasites and bacteria that infect millions globally. They cause deadly and debilitating diseases such as malaria, dengue, Chikungunya, yellow fever, Zika virus disease, leishmaniases and Chagas disease.’
Since the beginning of 2024, over 10 million dengue cases and over 5,000 dengue-related deaths have been reported from 80 countries/territories.
In the past month, the worst outbreak of the Chandipura virus in over 20 years has claimed the lives of at least 32 people, mostly children and teenagers, and has infected 80 individuals so far in India.
The Ebola virus is the deadliest and without treatment, up to 90% of cases are fatal. It caused the 2014–2016 outbreak in West Africa, the largest Ebola disease outbreak to date, with more than 28,600 cases reported.
The Nipah virus has been linked to dozens of deaths in Kerala state since it was first reported there in 2018. From July 1, 2017 to February 28, 2018, Brazil reported 723 confirmed cases of yellow fever in humans, resulting in 237 deaths. And then the Zika virus outbreak from 2015 to 2017 led to 3,500 babies being born with nervous system or eye damage.
To add to the trouble, a major drop in vaccinations must also be blamed. According to UNICEF and WHO's recent estimation, the number of children who did not receive a single dose of the vaccine increased from 13.9 million in 2022 to 14.5 million in 2023.
Each new strain seems more insidious than the last, and the race to develop vaccines and treatments is relentless.
We need medical studies on disease spread and multiple biological experiments to understand if a pathogen is a serious threat to humans. It can take some time to understand the pathogen, its life cycle, and its link to a specific human disease.
But as we grapple with these invisible enemies, one question looms large: who is to be blamed? In this article, let's delve deeper to determine just that and find out what's going wrong.
Climate Change
Rising global temperatures and changing weather patterns have altered the habitats and behaviors of disease vectors such as mosquitoes, ticks, and rodents. For example, warmer temperatures can extend the breeding season and geographic range of mosquitoes, leading to a higher incidence of diseases like malaria, dengue, and Zika virus in previously unaffected areas.
Increased rainfall can lead to more pools of water forming and droughts can lead to more people storing water, both of which create more breeding opportunities.
Furthermore, melting permafrost can release ancient bacteria and viruses that were frozen for thousands of years, bringing back diseases that we thought were gone. As glaciers and ice caps melt, these germs can get into our water supplies and make people sick.
Urbanization and Land Use
Currently, reports suggest that there 4.4 billion people, which is over 50% of the global population, live in cities and this figure is expected to rise to 68% by 2050.
Urbanization and changes in land use have significantly contributed to the rise in diseases. As cities expand and encroach upon natural habitats, humans and wildlife are brought into closer contact, creating opportunities for zoonotic diseases—those that jump from animals to humans—to spread.
Deforestation and habitat destruction force wildlife to migrate and adapt to new environments, often closer to human settlements, which increases the likelihood of disease transmission.
Moreover, rapid and unplanned urban growth often leads to crowded living conditions, inadequate sanitation, and poor waste management, all of which can exacerbate the spread of infectious diseases.
Not to forget, human activities also involve disruptive events such as wars and political conflicts, which can abruptly unsettle and destabilize large groups of people.
Travel
Global travel has made it easier for diseases to spread quickly around the world. When people fly or travel internationally, they can carry infections from one place to another before they even show symptoms, which makes it hard to control outbreaks.
Travelers may also visit areas with different disease profiles and bring these infections back to their home countries, where they can spread further.
This was starkly highlighted during the COVID-19 pandemic, where the virus spread to nearly every country within months. Similar patterns have been observed with other infectious diseases like SARS, H1N1 influenza, and Ebola.
Similarly, the shipping of foods and animals between countries also plays a role in spreading diseases. By transporting these items across borders, there's a risk of expanding the reach of parasites and other pathogens.
The Outlook
Given these myriad factors contributing to the rise of infectious diseases, it’s clear that our actions have far-reaching consequences. It's high time we reflect on our impact and take proactive measures to mitigate these threats.
It's not that we lack solutions; we know what needs to be done. We must invest in stronger public health systems, support and fund essential research, and adopt sustainable practices. Last but not least, global collaboration isn’t just a good idea—it’s crucial for ensuring the safety and health of future generations.
Edited by Harshajit Sarmah
