VIRAL TRANSMISSION IN A NUTSHELL

This infographic aims to simplify some general ways in which different species of viruses can transmit and infect humans. It is primarily divided into three sections: living vectors, non-living vectors, and non-vector transmission.

Living vectors are primarily insects (such as mosquitoes and ticks) that acts as an intermediate species for the virus. This means the vector can carry the virus from one human (via blood) to another to propagate it. Viruses that transfect through this manner are Zika and Dengue.

Aedes aegypti is an example of a living vector. Image source

Non-living vectors are items such as used needles and syringes. So, viruses such as HIV can move from one individual to another via used needles. This means that if someone with the virus was to use a syringe and another non-infected individual were to use the same syringe, the virus can then infect the other individual. Therefore, it is essential to be cautious of properly sterilizing equipment and using single-use needles when administrating medications.

Non-vector transmission occurs when the virus is directly transferred from one host to another. For example, transmission can occur through air droplets (saliva, sweat), wounds, genital secretions, and fecal matter. Viruses such as influenza and coronavirus are usually transmitted with droplets between individuals as they mainly infect the respiratory tract. Therefore, proper distancing measures must be taken, including avoiding physical contact and wearing masks, to prevent infection. Similarly, open wounds should be adequately treated and cleaned to prevent contamination from foreign matter. Hygiene is also paramount when avoiding the propagation of viruses such as rotavirus and papillomaviruses.

For more info, please have a look at the infographic or this resource.

References:

Flint, Jane, et al. Principles of Virology: Bundle (ASM Books). 4th ed., ASM Press, 2015.

Thaneswary Rajanderan
WISE GSS Secretary
PhD Candidate
Immunology and Infectious Diseases
Kensuke Hirasawa Lab (HSC 1809B)
Faculty of Medicine
Memorial University of Newfoundland