Hand-hygiene mitigation strategies against global disease spreading through the air transportation network

Christos Nicolaides; Demetris Avraam; Luis Cueto-Felgueroso; Marta C. González; Ruben Juanes

The contagion dynamics of infectious diseases are broadly described by the basic SIR model. However, the concept of SIR reactions excludes the effects of individual hygiene activities (like hand washing) from the model of infection transmissions. In that case, the infection reaction process is considered as independent from the hand cleanliness of the infected individuals. In our initial analysis, we first use the SIR model (disregarding the impact of hand-hygiene behavior) to estimate the capacity of airports to spread an infectious disease globally. We seed the disease in each of the world major airports and through simulations we track the contagion dynamics two weeks after the outbreak. We rank the airports according to their spreading capacity as quantified by the TSD of infected individuals 32 (Figure 2 -middle) . From the analysis, it is observed that the total traffic alone cannot predict the power of an airport to spread the disease (comparing left and middle panels in Figure 2 ), but should be accounted alongside with the location of each spreader airport and the spatial correlations with other influential airports in the network. NRT (Narita International Airport, Tokyo, Japan) and HNL (Honolulu International Airport, Honolulu, USA) airports are indicative examples, as they ranked in the 46th and 117th place by total traffic respectively, but they have large contribution in the acceleration and expansion of a disease contagion globally (ranked by TSD on the 7th and 30th place respectively). This happens because NRT and HNL combine three important features with high impact on the disease spreading. These are (i) they have direct connections with the world's biggest mega-hub airports, (ii) they operate long-range in-and out-bound international flights, and (iii) they are located in geographical conjunctive points between East and West 32 .