 There by Dr. O here this video I want to focus on mechanical versus biological transmission but before we get there let's talk about first of all vectors. So we're looking at two different ways that vectors can transmit diseases. So vectors are going to be animals that carry a pathogen from one host to another. So obviously we see the pictures here talking about flies and mosquitoes but they can be larger animals imagine like a mammal carrying rabies but so there are two different ways that vectors can actually spread a disease from one host to another. We have a mechanical transmission here on the left and then we have biological transmission. So in this image here a fly actually landed on fecal material and picked up some bacteria or some other pathogen and then it landed on this burger or whatever it is and transmitted the pathogen to the food, the person ate it and got sick. So this certainly can happen especially if you're being exposed to lots of fecal material that are working its way to your food. So it is known that let's see shigalosis which is a type of basilari dysentery can be spread from infected fecal material getting deposited onto food through animals, typhoid fever so diarrhea and dysentery diseases can actually be spread through this method of mechanical transmission. Now biological transmission is generally more complicated and involves like in the first case of mechanical transmission the fly or whatever we're talking about wasn't actually sick I was just carrying it on its body and physically moving it around. So biological transmission is going to be more complicated but here we see an example let's talk about the mosquito first and I'll give you a few other examples. So an infected mosquito is actually bites this person, let's say if we're talking about malaria for example the malaria parasite would be in the salivary glands of this mosquito so that's how the person would get infected with the bite and then the infection is going to be spread and get and be in other red blood cells then it'd be picked up by a second mosquito and carried to the next person. So that's a good example of biological transmission but there are two different types of biological transmission and or two different places where these organisms can be reproducing before they're spread to the next host and that would be in the gut or in the salivary glands. So I just mentioned this is an example of the salivary glands and then so this parasite would grow inside the mosquito and then be deposited when it when it dumped its saliva into you the human but a lot of parasites are gonna or organisms are gonna grow in the guts of the the vector and then think about so while an insect is biting you it's pooping on you basically so the bite creates a portal of entry the poop would be you know fecal material would be where the pathogen is and now it has it has a bite it has an entry a portal in so so the gut or salivary glands are two different places where this biological transmission can take place so a couple other examples we already mentioned the malaria being spread through by mosquitoes this would be how tick bites would lead to Lyme disease how lice biting could lead to typhus and then if you want to think about other types of animals I already mentioned rabies before but a mammal can bite you in and that would be an example of biological transmission of the rabies virus through their through their saliva so that is mechanical versus biological transmission of diseases through vectors so I hope this helps have a wonderful day be blessed