the final infectious disease that we are going to be looking at for this chapter is called tuberculosis also referred to as TB and TB is caused by two types of bacteria which fall under the group of pro carots uh remember bacteria just a bit of quick revision bacteria are organisms that have 70s ribosomes they have circular DNA and they also have a peptidoglycan cell wall this is a revision to this is a revision in chapter one The thing about TB is two types of pathogens may cause tuberculosis and the two pathogens are as follows microbacterium tuberculosis or micob bacterium bovis if a question asks you in the exam like uh name the pathogen that causes TB if they just ask you for one either one is fine okay however what we have to understand is how does TB spread because the way TB spreads through microbacterium tuberculosis and microbacterium Bas are quite different so for microbacterium tuberculosis what happens is the bacteria are inside our lungs because TB usually affects it can affect many different parts of the body TB but um the most common organ that is affected by TB are our lungs so uh the microbacterium tuberculosis bacteria are in the lungs and when we cough or when we speak or when we even just exhale we release out airborn droplets containing M tuberculosis and this droplets are then inhaled by the uninfected person so if a question asks you in the exam how does m tuberculosis spread you have to be a bit specific you have to say the release of Aon droplets containing the pathogen or M tuberculosis which are inhaled by another person however for Movis it's quite different because it starts from cattle or cows in the farm and the bacteria are actually in the cow and what happens here is we ingest milk or meat that contains the ambois pathogen and that's how TB spreads via micob bacterium bis so these are the two different ways in which uh tuberculosis can spread for M tuberculosis it's through airborn droplets and for Ovis it's from the infected Kettle so you have to know the distinction between these two now the symptoms of TB as I've mentioned earlier most cases of tuberculosis affect the lung there are cases of TB where it can affect your liver or even your bones your spine for that matter but we are going to focus more on the lungs when it affects the lungs it causes the lungs to start having these things known as tubes you don't have to memorize this tubes are just this um they just look like the circular nodules that start appearing in our lung tissues because this is due to the growth and damage from the bacteria and because it affects the lungs the symptoms are usually also lung related or chest related sometimes the person may have shortness of breath they may have chest pain Chron long-term coughs and other symptoms may include fever and quite commonly weight loss in fact in the 1700s TB was referred to as a disease known as consumption because this disease seemed to consume you from the inside like the person would be of a healthy body weight but due to TB as the disease lavaged their bodies uh they had this very severe weight loss that happened um and that is why it was known as cons consumption these days we don't call it consumption we know that it's known as tuberculosis just a bit of extra information for that personally I would try to memorize at least two symptoms at least go with the weight loss and also shortness of breath or difficulty breathing that's good enough for the exam now a very important thing I would like to tell you here is there is also something known as latent TB and latent TB just means that the pathogen is dant or inactive in fact we estimate that 30% of the human population actually have latent TB so one in three of us approximately will be walking around with this microbacterium pathogens in our body but the good news is the microbacteria the pathogens are inactive they're not damaging your body right because think about it TB can actually spread very easily uh through Airborne so it makes sense that it can spread from one person to another quite easily but just because the bacteria are in your body it doesn't mean that you have TB it's different from HIV because if you remember in my previous video I did say that if a person has latent HIV they may still be able to spread the disease but uh latent TB is a little bit different because the pathogen is dominant or inactive and the good news is it's not causing damage in your body that's one and the other good news is you will not be able to spread it to other people so that's fine but then comes the question when does the latent TB suddenly become active and you know cause you to have symptoms and start damaging your body right that usually starts to happen when the person is quite malnourished when they don't have enough nutrients they might have diabetes smoking which causes damage to the lungs and the most important thing is latent TB can become active if a person has a weakened immune system which happens due to HIV in fact if you remember in the previous video on HIV I did say that when your immune system becomes extremely weak it will cause a rise in opportunistic infections and one of that opportunistic infection was tuberculosis so you see the link here so in Malaysia usually uh what what doctors do is if you are diagnosed with TB most of the times doctors will also do a HIV test just to make sure that your immune system is still fine because it's associated with each other so then comes the question okay if the person has TB how do we treat it the main treatment for tuberculosis is antibiotics antibiotics are drugs or medicines that are able to kill bacteria or inhibit bacterial growth do not worry about antibiotics uh in detail because we will be talking about it in the next video the thing about TB is just because you have antibiotics doesn't mean it's easy to treat TB the reason is because multiple different antibiotics are given daily to the patient with active tuberculosis the antibiotics may include pynamite ethambutol rampin isonite and streptomycin now I know what you might be thinking do I need to memorize this no you don't have to memorize it but what you do need to know is multiple different antibiotics are given to the patients daily in fact in some cases the patients may need to eat a total of 10 to 15 tablets per day because some of those medications have to be taken uh twice or three times a day so it repeats itself so then comes the question why why do we have to give so many antibiotics at the same time the reason is because some of the microbacteria might be drug resistant or antibiotic resistant what that means is so let's say the person's lungs over here is filled with the micro bacteria and let's say the doctor just give pyramide now when pyramide or one type of antibiotic is given it May kill uh some of the bacteria but notice that some other bacteria survived because those bacteria are uninfected by pynamite so we they are antibiotic resistant or pyite resistant so the doctor gives a combination of maybe three to four different types of antibiotics simultaneously in this way we increase the chances of killing the bacteria so the bacteria may be resistant to one type of antibiotic but it's not resistant to another type of antibiotic that's how that works um and another very important thing that we have to know is the antibiotics are given through something known as dots you might be thinking oh dots what exactly is dots is dots something like you know like poka dots no it's not uh dots essentially means direct observation treatment short CA you don't have to memorize the meaning the long term you just have to note doots what that just means is the healthcare worker or the family member a responsible family member ensures that the patient takes their medication as prescribed because think about it if you expect a patient to eat four or five different types of antibiotics daily one of the common problems is patients may miss or forget to take their antibiotics and we don't want that to happen because if the patients miss the antibiotics or the patients forget to take their antibiotics it may give bacteria chance to mutate and become resistant to different types of antibiotics so we don't want that to happen so in hospitals when patients with TB are given antibiotics the nurse or the doctor has to stand in front of the patient and make sure that the patient eats it and swallows it so in the exam if a question asks you what are the treatments of TB you have to say multiple different antibiotics are given daily and uh the reason is because it's to increase chances of killing the bacteria uh and also the antibiotic are given through dots a very important thing to also remember and just understand here is the antibiotics are not given because some of my students may ask this question how long do the patients have to take the antibi biotics the antibiotics usually for TB it has to be taken for 6 to 9 months when you think about it 6 to 9 months is a long period of time for the patients to be taking different types of antibiotics that is why dots is important and we have to involve responsible family members and healthcare workers to ensure that the patient takes their medication and of course we have to then explain how do do we prevent the spread of tuberculosis so the first way in which tuberculosis can spread through the M tuberculosis pathogen uh is is the release of airbond droplets containing the pathogen and it's inhaled by another person if you do not want these pathogens to spread via the airborn droplets then logically what you need to do is you need to quarantine the infected person quarantine means that you separate the infected person from the uninfected person when they are at their most infectious okay so um people with tuberculosis uh they are their most infections during the the first two to 4 weeks so during that first two to four weeks the people with active TB should be quarantined especially if they showing a lot of symptoms and uh they should be kept separate from their family members or even the general public and they must also receive treatment during that time the second way is by contact tracing which is identifying close contacts for example let's say one person has TB and uh we the clinics or the hospitals will assess oh who's their child who's their partner uh who's their best friend who comes to visit them perhaps these people might have active tb2 and they spread it to that person so by identifying one sick person we can also identify the other people in the community who may also have active TB the third one that we just have to talk about are vaccines I am not going to go into the detail of vaccines because we will be elaborating on that in chapter 11 all we have to know about vaccines right now is there is a particular vaccine known as uh BCG you don't have to memorize the name of the vaccine but uh it's just good it is just good to know that there is a vaccine involved in the prevention of the spread of TB however it is just a 60 to 70% protection now another way in which TB can also spread is through the Ovis pathogen and it's by the infected Kettle and we ingest meat and milk that contains the ambois pathogen so one way in preventing the spread of ambois is by identifying the cat that contains tuberculosis and kill off the cow or the cattle so that it cannot spread it another method is also called the pasteurization of milk don't have to memorize the process of pasteurization but what you just do to the milk is you heat the milk up and rapidly or quickly cool it down what this does is if the milk contains the pathogen it will be killed due to the high temperature so even if you were to ingest the milk it is safe and this process is known as pasteurization there are also other ways of preventing the spread of TB remember I mentioned before that about 30% of the population may have latent TB so how do we prevent latent TB from becoming active remember latent TB becomes active when the person is malnourished they don't have enough nutrients they may have diabetes smoking or a weakened immune system so to prevent a latent TB from becoming active we must improve the nutrition of the person or the population so if the country has a lot of malnourished people our doctors nurses and nutritionists will have to work in a rather large scale to improve the general nutritional standard for the country or the public uh and of course that's easier said than done right but we have to give it a shot the second thing we have to to do is improve housing conditions and you see sometimes due to Poverty or due to substandard housing many people can live in one house like you know 15 people in a small house and I've seen this happen before by the way in certain communities this is bad because when you have so many people in one house number one there is a tendency I'm not saying in not in all cases but in a in a lot of cases the hygiene standards of the house or the cleanliness of the house can be quite poor and also the nutritional standards will be quite low as well and because they are all in one tightly confined space it is easy for TB to spread from one person to another so housing conditions have to be improved upon we can have for example three people living comfortably in a home but in this case to improve housing conditions well number one houses have to be built proper houses have to be built and number two housing has to be affordable for people which is well if you're in Malaysia especially in qualum po it's getting worse uh you know if I wanted a decent home all I'll get is a shoe box and that's not comfortable for me but again that's just you know my that's just a problem that I'm facing on a personal level but moving on uh and of course if people have HIV we do not want their HIV to lead to AIDS because remember if their immune system becomes too weak it may develop AIDS correct so it is imperative to start them on Art medications to prevent the weakening of the immune system so if people have HIV and you also put them on the art which is the medication that suppresses the HIV pathogen the their immune system will be protected and they will also have lesser chances of getting getting TB and spreading TB in the population of course then comes the question why is it difficult to eradicate TB all right so this is what we know about TB right now it is for the most part the common TB at least is spread through M tuberculosis in the Aon droplets Laten TB uh is where pathogen is dominant or inactive where about 30% of the population have it and people who are malale nourish diabetes uh smokers and also people with weakened immune system have a higher chance of getting active TB this is what we understand about the disease so far the first problem that we have in eradicating TB is the fact that it spreads easily through the air so any other person can inhale the pathogen and carry it in their body and just because they are not infected doesn't mean they do not have the pathogen in their body right and many parts of the world still have malnourished and poor populations and because they are malnourished if they have latent TB it might become active so that's what causes a rise in active tuberculosis and of course there is also a rise in people with HIV in the population um and people there are more people with weakened immune system and because they have a weakened immune system they may also develop tuberculosis as well number four is because of migrations of people the fact that TB spreads easily through the air and then marry that together with the fact that people are traveling from one part of the world to the other you will have a recipe for the easy spread of TB so increase in migration can happen due to work travel uh and of course war that is currently happening in the world right now Ukraine Russia uh Palestine Israel so these among other Wars by the way um so these kinds of uh situations will cause mass migrations of people and during mass migrations of people usually it is coupled with um people with having uh because because imagine the they are they uh they they are running away from a country that is won and they may not have enough nutrients so they they might develop malnourishment and they might also if they have latent TB they might suddenly develop active TB and this may be an issue too so help has to be given as soon as possible in those cases and one huge problem when it comes to TB is the fact that the micob bacterium which are the pathogens that cause tuberculosis they are evolving to become antibiotic resistant which means to say you have two people with TB represented by the green dots in the lung those are the pathogens person a when they are given antibiotics it kills off the pathogen but person B however when they are given the antibiotics the path only some pathogens died off and the other surviving pathogens are said to be antibiotic resistant and because it is antibiotic resistant person B may also may also spread the disease to other people let as well and this can be an issue that is why if you remember when we were talking about antibiotics I did say that doctors will usually give at least a combination of two to four different types of antibiotics to increase the chances of killing the bacteria but this list explains to us why TB is not an easy disease to irradicate I hope you understand this