Identification of virus Prepared by: Putri Shareen Binti Rosman

Types of viral infection Acute infections -relatively short duration with rapid discovery. Most viruses that infect humans, such as those that cause routine respiratory infections (e.g., cold viruses, influenza viruses) and gastrointestinal infections (e.g., Rotaviruses, Noroviruses),skin infection(e.g.,Varicella zoster virus) cause acute infections.

Types of viral infections Persistent infections - Viruses continually present in the body. - Late complications following acute infections. Also known as latent infection. Eg:HSV-1(fever blister),HSV-2(genital herpes). Chronic infection - the virus can be demonstrated in the body at all times and the disease may be present or absent for an extended period of time. - Eg: hepatitis B (caused by HBV) and hepatitis C (caused by HCV).

Slow infections - are ones in which the infectious agents gradually increase in number over a very long period of time during which no significant symptoms are seen. - Eg: include AIDS (caused by HIV-1 and HIV-2) and certain lentiviruses that cause tumors in animals.

Portals of entry and exit of viruses Virus can enter into our body at many different sites and these are called portals of entry. Respiratory Tract Genitourinary Tract Gastrointestinal Tract Skin/Mucous Membrane Transplacental (mother to fetus) Blood

Modes of Transmission reservoir to a susceptible host. The mechanism for transfer of an infectious agent from a reservoir to a susceptible host. Dr.M.ElBashaar

Means of Transmission Five Main Routes Droplet Airborne Common Vehicle (Food, blood) Vector-borne Contact Direct Contact Indirect Contact (Objects) Dr.M.ElBashaar

Sources and modes of transmission of infection 1. Person-to-Person Spread Skin-to-skin contact, clothes, (viral as HSV1) Droplets during coughing, sneezing (common cold, flu, swine flu, smallpox,measles,SARS) Stool-to-mouth (fecal-oral) spread, usually via dirty hands or utensils (hepatitis A,poliomyelitis) Dr.M.ElBashaar

Sources and modes of transmission of infection Sexually transmitted (gonorrhea, genital HSV2, genital warts (human papillomavirus – HPV). Blood-to-blood contact by: contaminated needles, usually by drug addicts or health workers (hepatitis B, C, AIDS) blood transfusion (hepatitis B,C, AIDS, viral hemorrhagic fevers) Vectors: rabies anthropod:mosquitoes (Malaria, Dengue,Yellow fever) Dr.M.ElBashaar

Sources and modes of transmission of infection Spread from mother to fetus during pregnancy (hepatitis B, C, HIV, HSV-1, HSV-2, rubella, varicella, bird flu). Spread from mother to fetus Food poisoning is an infection of the gastrointestinal tract caused by microbes from contaminated food:Eg: Enterovirus Food poisoning Dr.M.ElBashaar

Viral Diseases Diseases caused by viruses has been known for thousand years ago. Antibiotics are not effective in killing viruses Certain viruses are also linked to cancer in human such as Hepatitis B (liver cancer),Epstein-Barr virus (Burkitt’s Lymphoma) and Human Papilomavirus (cervical cancer).

Important viral diseases AIDS:Immune system failure Common cold:Sinus congestion Ebola:High fever,uncontrolled bleeding Hepatitis A:Flu like symptom,swollen liver Hepatitis B:Flu-like symptom,swollen liver. Influenza (flu):Fever,chills,sneezing,body aches. Mumps:Painful swelling of saliva glands Polio:Fever,headachenstiff neck,paralysis Rabies: Mental depression,madness,paralysis

SARS:High fever,headche,dry cough,death. Smallpox:Malaise,fever,blisters,blindness Yellow fever:Fever,weakness,yelllow skin.

RNA viruses (+ve sense) Picornaviridae Togaviridae Flaviviridae Retroviridae MIC208 - VIROLOGY 15

RNA viruses (-ve sense) Paramyxoviridae Rhabdoviridae Orthomyxoviridae Filoviridae Bunyaviridae Reoviridae (double-stranded) MIC208 - VIROLOGY 16

DNA viruses Double – stranded Adenoviridae Herpesviridae Poxviridae Papovaviridae Hepadnaviridae Single – stranded o Parvoridae MIC208 - VIROLOGY 17

Assignment 1 Per group have 4-5 per group = 16 groups Presentation after CNY holiday Each group have 5 minutes for presentation Represent 5% marks for assessment Explain the genome content, viral morphology, modes of transmission, infection in human,treatment. MIC208 - VIROLOGY 18