Monday, February 3, 2014

“Malaria has a one way airline ticket to visit you!”

Zhuojie, H., Das, A., Youliang, Q., & Tatem, A. J. (2012). Web-based GIS: the vector-borne disease airline importation risk (VBD-AIR) tool. International Journal Of Health Geographics11(1), 33-46. doi:10.1186/1476-072X-11-33 (accessed February 2, 2014).

The past decade has seen a dramatic increase in international travel and now passengers can travel around the world in a matter of hours. However, this also increases the risk of diseases being spread around the world or vector-borne diseases, such as malaria, dengue, yellow fever, and chikungunya, establishing themselves in new locations. In their study, Zhuojie et al. (2012) use the GIS tool Vector-Borne Disease Airline Importation Risk Tool (VBD-AIR) to study how vector-borne diseases can spread by using international air routes. Current models are static and do not take into account climate-driven seasonal fluctuations that can prevent vector-borne diseases from spreading to a new location.
A) Airport locations
B) Air routes

For example, I fly to Rio de Janeiro in February for carnival and do not return back to Austin until June. While there I get bitten by mosquitoes and some of them just happen to hitch a flight back to Austin via the aircraft’s wheel well. Under this scenario, my mosquito friends may establish themselves in Austin and being spreading malaria in Central Texas. If I returned back to Austin during the month of February, then there would be a low risk of mosquitoes from Brazil surviving in Austin because of the winter season. Current models do not account for seasonal variations.

Color scale indicates predicted unsuitable to suitable conditions as a continuous scale from yellow to dark blue.
A) Predicated distribution of chikungunya outbreaks
B) Climatic and environmental suitability of Aedes albopictus (mosquito that carries malaria)

VBD-AIR uses data from airport locations, air routes, disease and vector distributions, global climate data, and travel time. For this reason, VBD-AIR is a better tool to use in anaylizing the spread of vector-borne diseases.

Malaria, dengue, yellow fever, and chikungunya are transmitted by mosquitoes. Non-endemic countries are seeing increasing cases of these diseases among travelers or returning migrants. Dengue fever has seen a reemergence due to air travel. The same is occurring with yellow fever, but the disease has spread from South America and Africa to Asia, where it is not commonly found. As for chikungunya, the disease has spread its range.

Zhuojie et al. (2012) use three types of mosquitoes for VBD-AIR: Aedes aegypti, Aedes albopictus, and Anopheles. Aegypti, which spreads dengue fever, chikungunya, and yellow fever, is native in Africa, but it is now found in tropical regions throughout the world. Albopictus can spread dengue, yellow, fever, and West Nile virus; however, this type of mosquito is a poor vector in spreading diseases. Anopheles transmits malaria. In order for these mosquitoes to establish themselves in a new area, they need the right temperature, rainfall, and humidity.

The enemy! Aedes albopictus

 Next, the authors used VBD-AIR to create a website were air travelers can visit to create a risk assessment of their travels and vector-borne diseases. Travelers can now see how vector distribution, seasonal climate changes, and changing air traffic are interrelated in spreading vector-borne diseases. VBD-AIR illustrates how different regions, airports, and air routes carry varying risks in spreading vector diseases.
VBD-AIR can be used to model health risks and assist medical personnel in screening patients who just returned from overseas travel. Furthermore, VBD-AIR helps travelers to assess their risks to vector-borne diseases so that they can better protect themselves. Next time I travel abroad, I’ll use VBD-AIR and prevent mosquitoes from hitching a ride back home with me.  


  1. What I find interesting the the interconnectedness of the Global North, and the potential that is shown for mosquito that carries malaria in the global south. The risk comes from the interconnectedness, but now with rapid development of the emerging markets in the Global South, the AirPort maps a sure to get more red all over the world. This will open up the new areas to global connectivity and could lead to even more spreading of disease. This is a good case for global health initiatives, because an outbreak in a far away place is easily brought close to home with our increasingly interconnected world.

  2. Okay first of all I loved this article because it is one of the few that I actually understand. Thank you for that. Second of all, I
    thought it was really cool that you used a personal example like how you are going to Brazil and then turning that into a hypothetical
    situation with the mosquito hitching a ride back to ATX. I also thought the idea of using GIS to track plane flights and pin point disease
    was really interesting. With disease becoming more widespread due to more international travel, this could be a game changer.

  3. I hadn't thought of that perspective before. It gives you a whole new view of travel in that not only your body, but the air around your body can bring diseases back. One is easy to control with a check-up and proper medical care, but the other is something you may not even realize and have little way of controlling. It's a little known cause, but deserves awareness all the same.