World Dengue Day – In conversation with Aisha Barkhad

Aisha Barkhad, Global Health PhD Student and current Canadian Youth Delegate to the World Health Assembly and the Pan American Health Organization Directing Council, has been engaged in research for the prevention and treatment of dengue. June 15th is World Dengue Day, and the theme this year is Prevention: Our Responsibility for a Safer Tomorrow. Tina Lines, Advocacy and Policy Officer, spoke with Aisha Barkhad on May 9th while carrying out some of her dengue research in São Paulo, Brazil. We are sharing this interview in recognition of World Dengue Day 2024.

Tina – Aisha, can you tell us a little bit about yourself and your work on Dengue?

Aisha – Absolutely. I’m a 3rd year PhD student at McMaster University, and I’m doing my PhD in Global Health. As you know I’m doing my work on dengue. It’s important to consider dengue as a really neglected tropical disease. Today, as many as 60% of dengue cases are in Latin America and the Caribbean, where Dengue is endemic. These documented outbreaks are becoming much bigger and more frequent, and much harder to control in recent years.

Within my research in particular, I think it’s important to consider that dengue transmission functions within an epidemiological system, or epi-system, which means that there are a number of factors that influence the epidemiological patterns of the disease. I believe that what we need are multi-level analysis for climate-sensitive problems like dengue.

Dengue research in Latin America is growing in breadth and in depth, but knowledge gaps still exist and there are a lot of limitations in this region. Some limitations include a lack of funding, resources, data, a lack of inter-connected and linking health data. Overcoming these limitations requires multi-disciplinary and inter-professional collaboration. So, we need efforts between health officials, researchers, students, program managers, governments and communities within Latin America.

The Ecohealth approach is the approach of my work. Ecohealth looks at the relationship between the human-animal-environment interface. And so there is an evident and urgent need in Latin America to find a comprehensive way to understanding this dengue epi-system. The purpose of my work and the research that I do at McMaster is applying this Ecohealth approach to investigate the dengue epi-systems in Latin America and the Caribbean. Then, to mobilize knowledge in dengue prevention and control practice, policy and programs within the region.

Tina – What resonates with you about this theme for World Dengue Day – Prevention: Our responsibility for a safer tomorrow?

AishaThe theme this year is so important. It resonates with me because it underscores the critical role that everyone (and, I mean everyone) plays in preventing dengue, and that includes governments from around the world. And here in Canada, even though we might not see dengue as a huge problem, it is a neglected sub-tropical/tropical disease that we might believe won’t affect us, but this theme emphasizes the collective responsibility that we all have – individuals, communities and global organizations to take pro-active measures to prevent these diseases. And, I’m not just talking about dengue, but also other neglected tropical diseases that are spread by the same vector for dengue – the Aedes aegypti mosquito. This is the same vector for the Zika virus and Chikungunya virus, and ultimately [we can] reduce its impact on public health and the strain that this has on health systems globally.

This theme highlights the mobilization of knowledge, education, awareness, actions through changes to behaviour and practice, such as eliminating mosquito breeding sites and practicing preventative control measures. Also, we can support our public health initiatives that are aimed at preventing dengue. This theme highlights the longer-term goal of creating a safer and healthier environment, and supporting communities to achieve a future free of dengue.

Tina – We are hearing so much about Dengue these days. What’s changed for dengue recently that has put it into the headlines?

Aisha – I really like this question because it’s focused on what’s happening now, and why it’s such a serious issue. Several factors have contributed to dengue getting more attention. The first reason is that there are more frequent and burdensome dengue outbreaks in various parts of the world including in São Paulo, Brazil where I am, where we are experiencing the largest dengue outbreak in history. This itself is drawing a lot of media attention.

The reasons why we are seeing so many more outbreaks matter because researchers and scientists have been screaming from the rooftops for decades now that the climate is changing and as it changes, it’s causing dengue to reach new and different areas of the world impacting immunologically naïve populations. So, changes to the climate are changing the ecosystems that host the vector for dengue – the Aedes aegypti mosquito that I mentioned – making their bionomics more durable, more suitable, more optimal for dengue infection. As the climate changes, and as we humans are altering the way that we interact with the land and environment, altering it’s use and impacting the composition of the mosquito population in unprecedented ways.

Another reason why we are seeing dengue in the headlines is because the dengue burden goes hand in hand with the climate crisis. I think one last reason we are seeing dengue in the headlines, and this is a more positive note, is because of the development and approval of dengue vaccines that are gaining a lot of attention. And while vaccines have been developed, their effectiveness, distribution and challenges of implementing the rollout of these vaccines have been topics of discussion. The dengue vaccine here in Brazil will prioritize children and teens aged 10-14 right now, since this age group has exhibited the highest rates of hospitalizations. And so, as we are able to vaccinate amongst diverse populations, I think we will see more of this in the headlines as well.

Tina – So, vaccines are being rolled out, and the age group 10-14 are the most affected by dengue?

Aisha – That’s right, that’s why we do want to reach this group the earliest, and the hope is that once we do reach the priority groups then we can start distributing the vaccine amongst the general population including the adults. But that’s going to take time since the vaccine is relatively new and it’s only been rolled out since March (that’s only a couple of months), and over the next couple of years, the government of Brazil will work with scientists like my supervisor here at the University of São Paulo to be able to get this vaccine rolled out as soon as possible to everyone.

Tina – You’ve talked a lot about dengue in the context of Latin America. Can you describe the global burden of dengue?

Aisha – I’ll add that dengue is endemic not just in Latin America, but in more than 100 countries around the world in Asia, the Pacific, Africa and the Caribbean as well in tropical and sub-tropical regions. It’s also estimated that half of the world’s population is at risk of dengue infection, and I think that’s a huge number. While many of these infections are asymptomatic and produce very mild illness, dengue can occasionally cause severe illness – hemorrhagic fever or dengue shock syndrome which can be fatal. One more thing that I might add about the dengue vector, Aedes aegypti, is that it has largely evolved around human settlements and urban environments, and so it even evolved to bite humans when they are most active during daytime hours. In Canada, we are used to mosquitos biting at dawn or dusk, but this vector has evolved and adapted in a different way, even to travel with humans, on buses, boats, cars and planes. We have to think about the way this vector is interacting with us in our daily lives. That will be the key to understanding and explaining the global dengue burden.

Tina – What are some of the ways in which you’ve been able to engage other students and young professionals in this work?

Aisha – That’s something I think about every day. I’m trying to find like-minded individuals that might be able to help me create a network. This year I am the 2024 Canadian youth delegate for the World Health Assembly/Pan American Health Organization Directing Counsel and the priorities are to promote knowledge and strategize advocacy efforts among youth regarding the impact of climate change on our health. From there, I can start thinking about engaging youth in workshops, webinars, roundtable discussions where we can discuss the general impact of climate change on health, but also hone in on vector borne infectious diseases, and the importance of dengue.

I’m also mentoring youth through the University of Waterloo and the Canadian Association for Global Health Mentorship program, and I am involving my mentees in my research as a PhD student, and they are assisting me with the work that I get to do and the studies that I get to write. I am also launching an eco-society group at my university – McMaster University, to get youth involved. This is something that I’m inspired to do through the Ecohealth approach that I work with. I am also using platforms like this one to be able to reach students and early career researchers like myself to be able to create a network and inspire connectedness and champion youth voices – spreading awareness about the risks and global burden of dengue.

Tina – What do you want Canadians to know about Dengue?

Aisha – I think dengue really posses a significant public health challenge globally, and that does not exclude Canada. Canada is not the most tropical region of the world, so these diseases may not be prevalent or a priority. However, I think we need to think about the climate crisis and think about Canada as being one of the top countries being affected by climate change. As the world gets warmer and as rainfall patterns continue to shift, Canada will be a more viable place for the dengue vector to survive. By 2080, if all climate indicators remain the same as today and we fail to make the necessary changes we need to protect our planet, the Aedes aegypti vector and dengue and all the other viruses it’s able to carry will be amongst us in Southern Ontario. So, by then, more than 6 billion people (more than half) will be at risk of dengue globally. This is why Canadians and Canada should act now for prevention – which is the theme of World Dengue Day – with coordinated efforts from our governments, public health agencies, and our researchers (that need to be funded).

We need to spread knowledge within our communities and mitigate the impact and strategize climate change adaptation efforts. Because when we do strategize climate change adaptation efforts, we are ultimately preventing dengue. That’s what I think Canadians should know.