Communicable Diseases

Alternative transcript:

pathogens have a simple life cycle: infect a host Reproduce or replicate in the case of viruses) inside the host, Spread from their host and infect other organisms. A protein coat called a capsid. The genetic material (ONA or RNA). coop A virus does not have any cellular structure. A virus does not carry out any of the life process except for maning copies of irself (replication). For the above reasons, a vinus is not considered a living thing. A vinus can only replicare inside a host cell. A virus inserts its genetic material into a host cell. Then the host cell is programmed to produce virou DNA or REA. Then the host all is made to synthesise virou protein. Viral I 2. protein is assembled with DNA or RNA and new virus particles are made which then burst open the cell to infect other cells. Spread of pathogens Airborne - Droplets containing the pathogen is propelled into the air when the infected person sneezes. When these droplers enter a healthy person, the pathogens enter through his or her airways. Eg (comm cold virus). Through dirty water Unsterilised water may contain pathogens (Eg. cholera bacterium) 3. Through contaminated food Uncooked or reheated food may contain pathogens (Eg. E coli bacterium - Causing food poisoning). 4. Passed on by another animal called a rector. A vector is an animal that spreads a communicable disease. leg. mosquito is the rector that spreads movaria). Malaña is not Caused by mosquito but by plasmodium falciparum, a protist. 5. By direct physical contact (either sexual or non-sexual contact). STO (sexually transmitted diseases) are spread from an infected person to a non-infected person which is why bodily fluids are exchanged. (Eg. STD, Chlamydia is a bacterial patrogen that is transmitted by sexual contact with an infected person. Viral diseases Measies Measles is caused by a virus. Highly infectious and usually transmitted amonor young children. Transmission: Airbome (tiny droplets containing the measles virus is propelled in the air when an infected person sneezes). Symptoms : fever, a red skin rash Prevention : vaccinating " babies be foetal More serious complications in pregnant women could abnormalities, in adult male measles may cause sterility. HIV/AIDS Caused by human immunodefiency virus. a Transmission: Body fluids are shared between an infected person to non- infected person. (eg. during unprotected sex, by shared use of needles. especially among drug addicks. From an infected mum to her children by breast-feeding. The virus attacks the immune cells and at a later stage when the immune system is compromised by the virus the incerted person will become unable to fight even simple infections such as the common cold. This love stage of HWV infection is called AIDS (Acquired. immunodetiency syndrome). There is no cure but antiviral drugs that can slow down the progress. of HIV infection to AIDS. There is currently no vaccines available to prevent an infection Symptoms. An infected person may not show any symptoms at all for as long as 5 to 10 years. Symptoms become mostly apparent after the disease has progressed to the extent of considerable damage to the immune system.... Bagerial diseases caused by pathogenic bacteria. All bactena are pronarycles (have no nucleus containing ONA). Larger than viruses but only visible under a microscope. Bacteria live inside the host but not inside the host cells (viruses replicate inside the host cells). Bacteria reproduce asexually by binary rission. Bacteria are living things as they complete the 7 life processes. Bacterial infections Salmonella The salmoneua bacterium causes the infection to both warm blooded and cold blooded animals. Transmission : contaminated food eg. food cooked in unhygienic conditions / food not cooked well / food that has been reheated Symptoms : vomiting, diarrhoea, cramps, fever Control: poultry are vaccinated against salmonella to controt the spread Gonorrhoea It is a STD (sexually transmitted disease) caused by a bacterium called Neisseria gonorrhoeae. Symptoms! painful sensation when passing urine, discharge of thin green fluid from the vagina or penis. Treatment: Antibiotics such as penicillin. ick Fungal diseases Fungi are eukaryotes (have a nucleus containing DNA). Either unicellwar (eg. yeast) or muyricellular leg. mushkoms).. Fungi have a cell way made of chitin (not cellulose). Reminder! Plant cell wall - allwyose. Bacterial all wall - murein Fungal cell wall - chitin. Animal cell wall - no cell wall They produce spores for sexual reproduction rather than pulen and ova in plants. Fungi have hyphae. These are Hilament- like smuuctures that spread out. O U 0 only pathogenic fungi cause infections. Spores hyphae Athlete's foot caused by a fungur affecting people's feet.. Symptoms: Itching I flaking and blistering. Treatment: keeping the infected feet any and applying antifungal creams. Transmission in communcu creas where people walk wim benefout es. swimming poor Ringworms caused by a fungus (not a worm). Symptoms : Ring - Like rash on the skin. Treatment: Antifungal creams. Pronst diseases Prorists are prokaryotic microorganisms. Either uni-cellulor or multicellular without rissues i Fungi, Diants, animais. have rissues). Malaria A disease: caused by a prorist caved plasmodium Transmission: Mosquito acB as the vector that spreads malaria. Symptoms : fever I liredness | vomiting Theadache. The protist reproduces inside the human liver, Prevention : avoid being bitten by the mosquito leg, using mosquino neb. and insect repellent sprays containing insectivides (chemicals that will insects). Mosquitos (ay eggs in stagnant (not moving) water so clearing puddys. and pools. No vaccination available. Treatment: Anti malaurian drugs.