The World of Viruses

The world of VIRUSES : The world of VIRUSES Dr. Aman Biswas

Hit at … http://bisbio.inorCall bisbio.in at 09814016083, 09855516083oremail … bisbioin@gmail.com or amanbiswas60@gmail.com : Hit at … http://bisbio.inorCall bisbio.in at 09814016083, 09855516083oremail … bisbioin@gmail.com or amanbiswas60@gmail.com For all your Biology Problems UGC/CSIR NET Life Sciences AIPMT and State PMT SAT and GRE Advance Program Biology Civil Services Entrance to Biotechnology and Post graduate Sciences Entrance to BSc Nursing

Where can viruses be ? : Where can viruses be ? 6.77 Billion ..Humans

Are we the problem or Is it Mr. Virus ? : Are we the problem or Is it Mr. Virus ? We (all adult humans) are not a cancer that propagates unknowingly. We have intelligence. We can see that if one overpopulates its home, it will die out. All our major global problems have overpopulation as their base cause.

Populations cut down by Flu !!! : Populations cut down by Flu !!! We no longer have another continent to explore and invade with our minions. We cannot pretend we are in a time whence increasing our numbers is an aid to our future as it was in Biblical times. We are not so stupid as to believe any one race or nation has any more rights to this Earth as do the birds in the sky, the fish in the sea or the trees on the hills.

Think soon !!!!!!!!! : Think soon !!!!!!!!! A serious issue Consider before it is far too late. Fresh water, food, means to live and build protective cover are diminishing exponentially. The fact is…… our growing numbers A big problem.

Viruses …control our population ? : Viruses …control our population ? If we don’t check population Swine flu or viruses will !!!!!!

Do you know ? : Do you know ? Smallpox killed 300 million in the 20th Century. AIDS killed 11,700,000 worldwide Influenza killed In 1927 ……………… 21million deaths In 1940s ………………50-100 million deaths In 2002 ………………., 50-100 million deaths

Slide 9 : Approximately 1400 pathogen species are currently recognized. Fewer than 200 of these are viruses, but novel virus species are being reported in humans at a rate of over two per year, much faster than for other kinds.

Disease causing Human Viruses : Disease causing Human Viruses Pneumotropic viral diseases Involving respiratory tract Influenza Common colds.

Slide 11 : Dermotropic viral diseases Involving mainly skins Measles Chicken pox Small pox

Viscerotropic viral diseases : Viscerotropic viral diseases Involving mainly internal organs Yellow fever Dengue fever Hepatitis

Neurotropic viral diseases : Neurotropic viral diseases Involving mainly central nervous system Rabies Polio Encephalitis.

Influenza A : Influenza A Single-stranded, segmented RNA virus. Of the orthomyxoviridae family. Cause influenza to birds and few mammals

Influenza virus A : Influenza virus A Causing flu diseases … Bird Human Swine Horse Dog Cat

DECLARED EPIDEMIC KILLER : DECLARED EPIDEMIC KILLER A deadly influenza outbreak began in 1918 Spread around the world, killing more people than any other outbreak of disease in human history. In Arkansas alone, the flu killed about 7,000 people, several times more than the state lost during World War I. World Health Officials seek to prevent ……. An outbreak of a similar influenza epidemic mutated from swine or “bird flu” from poultry.

Variants …named according to their deadliness in poultry, especially chickens : Variants …named according to their deadliness in poultry, especially chickens Low Pathogenic Avian Influenza (LPAI) Highly Pathogenic Avian Influenza (HPAI), also called: deadly flu or death flu.

Influenza vaccine : Influenza vaccine Trivalent vaccine Consisting of haemaglutin (HA) surface glycoprotein components from influenza H3N2, H1N1 and B Influenza.

Effectiveness of Vaccination : Effectiveness of Vaccination Flu vaccines are available both as An injection of killed virus (or flu shot) and Nasal spray of live attenuated influenza virus (LAIV) (sold as FluMist in the United States). Effective against influenza But not perfect.

What is Antigenic Shift and Drift ? : What is Antigenic Shift and Drift ?

Antigenic Drift : Antigenic Drift When spread by droplets or direct contact, the virus, if not killed by the host's immune system, replicates in the respiratory tract and damages host cells. Influenza type A viruses undergo two kinds of changes. One is a series of mutations that occurs over time and causes a gradual evolution of the virus.

Antigenic Shift : Antigenic Shift The other kind of change is an abrupt change in the hemagglutinin and/or the neuraminidase proteins = Antigenic shift. In this case, a new subtype of the virus suddenly emerges. Type A viruses undergo both kinds of changes Influenza type B viruses change only by the more gradual process of antigenic drift and therefore do not cause pandemics.

Slide 26 : Type A viruses

First human infection : First human infection Influenza virus, as a pathogenic entity for chickens Known since the 19th century. In1997, the first human infection case with fatality The virus identified as strain H5N1 Found in Hong Kong, China, reminding us the virus is expanding its host range from birds to mammalians..

SARS : SARS In 2003. … outbreak of SARS (Severe acute respiratory syndrome) One human fatal case was surprisingly diagnosed with an H5N1 virus isolation. First human infection case in the mainland China. Now in15 countries up to early 2009 have human infections of H5N1 influenza virus.

RETROVIRA..HIV and Oncovira ds RNA viruses : RETROVIRA..HIV and Oncovira ds RNA viruses Rapid weight loss Dry cough Recurring fever or profuse night sweats Profound and unexplained fatigue Swollen lymph glands in the armpits, groin, or neck Diarrhea that lasts for more than a week White spots or unusual blemishes on the tongue, in the mouth, or in the throat Pneumonia Red, brown, pink, or purplish blotches on or under the skin or inside the mouth, nose, or eyelids Memory loss, depression, and other neurological disorders What are the Symptoms of HIV ?

Binding of HIV with our cells.. : Binding of HIV with our cells.. HIV has glycoproteins…. gp41 and gp120. The attachment of HIV to a TH cell is initiated by the binding of the HIV gp 120 molecule to the CD4 receptor. Then gp120 undergoes a conformational change Binds to a second molecule… a coreceptor, on the surface of the target cell the chemokine receptor expressed on T cells .

Number of HIV infected globally… : Number of HIV infected globally… Around 30.8 million adults and more than 2 million children were living with HIV 2 million deaths from AIDS occur annually. Abundant in Africa and India Spread through blood transfusions or Sexually transmitted According to estimates from the UNAIDS 2008 Report on the global AIDS epidemic,

How drugs work against HIV? : How drugs work against HIV?

: Rous in 1911 showed … A Virus caused chicken sarcoma Now estimated ..20% of human tumours have a viral risk factor. Viruses producing tumours = oncogenic viruses. ONCOGENIC VIRUS

Some Common Oncovira : Some Common Oncovira Epstein Barr virus .. Burkitt’s lymphoma Hepatitis B .. Hepatocellular carcinoma Human papilloma .. Skin carcinoma .. Cervical cancer .. Penile cancer Human T cell ..T cell leukaemia leukaemia SV 40 (Simian virus) .. …Leukaemia

Epstein Barr virus… Burkitt’s lymphoma : Epstein Barr virus… Burkitt’s lymphoma

Human papilloma : Human papilloma

Slide 38 : Hepatitis B.. Hepatocellular carcinoma

Viruses interact with Oncogenes : Viruses interact with Oncogenes Cancer-promoting oncogenes are often activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against Apoptosis. loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments. Tumor suppressing genes are often inactivated in cancer cells, resulting in the loss of normal functions in those cells.. accurate DNA replication, control over the cyclins and cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system.

Viruses also interact with enzyme, telomerase : Viruses also interact with enzyme, telomerase In 1978, Blackburn and Joseph G. Gall of Yale University, found that the… Telomeres in Tetrahymena, a ciliated, protozoan, contained an extremely short, simple sequence of nucleotides-TTGGGG-repeated over and over.

Viruses also interact with enzyme telomerase : Viruses also interact with enzyme telomerase Telomeres are rich in T and G nucleotides. Every species, however, has a characteristic average. In Tetrahymena, the average telomere has 70 repeats; In humans, 2000 repeats

Rubella ..Togavirus : Rubella ..Togavirus Incubation:  2-3 weeks Rubella virus is spread via respiratory transmission from human to human.  Virus is shed in oropharyngeal secretions and is highly transmissible.  Adults usually acquire lifelong immunity after the primary infection.

Symptoms : Symptoms Appearance of fine, pink macules on the face.  This rash typically spreads to the trunk and limbs and fades within 48 hours.  Enlargement of cervical lymph nodes is common.  Rare complications of Rubella virus infection include thrombocytopenic purpura .

Rubella virus infection is usually the appearance of fine, pink macules on the face. : Rubella virus infection is usually the appearance of fine, pink macules on the face.

Rubella virus vaccine : Rubella virus vaccine The live, attenuated Rubella virus vaccine Given in two shots At 15 months and 5 years Produces lasting immunity in more that 90% of recipients.

Congenital Rubella Syndrome (CRS) : Congenital Rubella Syndrome (CRS) Includes Neurosensory deafness Blindness Congenital heart disease Microcephaly with mental retardation Growth retardation Hepatosplenomegaly.

Chickenpox… Herpesvirus : Chickenpox… Herpesvirus Classic childhood diseases One of the most contagious. The affected child or adult may develop hundreds of itchy, fluid-filled blisters that burst and form crusts. Chickenpox is caused by a varicella-zoster, a member of the herpesvirus family. Lifelong immunity for chickenpox generally follows the disease

Slide 49 : One to two days of fever and sore throat . Within 24 hours of these symptoms, a characteristic rash develops initially on the torso Then spreads over the next seven to 10 days outward to the head, arms, and legs. The rash progresses through a predictable evolution from a red papule ("bug bite") appearance to blister ("vesicle") to pustule and then scabs over.

Chickenpox of adults ?? Shingles : Chickenpox of adults ?? Shingles Also termed herpes zoster Reactivation of the herpes zoster virus (varicella-zoster virus, or VZV) Results in a painful localized skin rash, usually with blisters (fluid filled sacks) on top of the reddish skin. Virus (varicella) remains in a dormant state in the body in the root of nerves that control sensation. In about one out of five people, the virus "wakes up," often many years after the chickenpox infection. The virus then travels along a sensory nerve into the skin and causes shingles. The majority of patients who get shingles are over the age of 60.

Reye syndrome : Reye syndrome A sudden, sometimes fatal, disease of the brain (encephalopathy) with degeneration of the liver, occurs in children (most cases 4-12 years of age), comes after the chickenpox (varicella) or an influenza-type illness, and is associated with taking medications containing aspirin.

Smallpox.. Orthopox virus : Smallpox.. Orthopox virus Smallpox virus, Variola, is the only disease that has been completely wiped out throughout the world. Smallpox is also potentially one of the most devastating biological weapons ever conceived. Last case was reported on October 26, 1977. (An unvaccinated hospital cook in Somalia was the last person to naturally contract smallpox.) WHO officially declared smallpox eradicated in 1980.

Symptoms : Symptoms After infection, symptoms may take from 7-17 days to appear for major types of smallpox. The virus begins growing in the bloodstream 72-96 hours after infection, but no obvious symptoms appear immediately. People who have contracted smallpox initially develop such symptoms as fever, body aches, headache, chills and particularly, backache. Over half of people with smallpox experience chills and vomiting. About 15% become confused. A rash appears 48-72 hours after the initial symptoms and turns into virus-filled sores, which later scab over. The process can take up to 2 weeks.

Virus-filled sores, which later scab over : Virus-filled sores, which later scab over

Yellow fever virus.. Flavivirus : Yellow fever virus.. Flavivirus Remains silent in the body during an incubation period of three to six days. There are then two disease phases. “Acute", phase is normally characterized by fever, muscle pain (with prominent backache), headache, shivers, loss of appetite, nausea and/or vomiting. Often, the high fever is paradoxically associated with a slow pulse. After three to four days most patients improve and their symptoms disappear.

Yellow fever virus.. Flavivirus : Yellow fever virus.. Flavivirus However, 15% enter a "toxic phase" within 24 hours. Fever reappears and several body systems are affected. The patient rapidly develops jaundice and complains of abdominal pain with vomiting. Bleeding can occur from the mouth, nose, eyes and/or stomach.

Slide 60 : Once this happens, blood appears in the vomit and faeces. Kidney function deteriorates This can range from abnormal protein levels in the urine (albuminuria) to complete kidney failure with no urine production (anuria). Half of the patients in the "toxic phase" die within 10-14 days. The remainder recover without significant organ damage. Yellow fever virus.. Flavivirus

AedesThe vector : AedesThe vector The virus is carried from female Aedes mosquito (the vector). Vaccination …..for preventing yellow fever.

Dengue..flavivirus : Dengue..flavivirus First isolated in India in 1945. Incubation period …………3- 15 days. Aedes aegypti …..principal vector of Dengue. Dengue cases …..7-16 thousand per annum.

Slide 63 : “Dengue Triad” Fever, Rash, and Headache (and other pains Other names….. "breakbone" … intense joint and muscle pain "dandy fever." Slaves in the West Indies who contracted dengue were said to have dandy fever because of their postures and gait.

Slide 64 : Painful aching in the legs and joints occurs during the first hours of illness. The temperature rises quickly as high as 104° F (40° C), with Bradycardia and hypotension). The eyes become reddened. The glands (lymph nodes) in the neck and groin are often swollen. Fever last for two to four days,

Slide 65 : After a day a second rapid rise in temperature follows. A characteristic rash appears along with the fever and spreads from the extremities to cover the entire body except the face. The palms and soles may be bright red and swollen.

Dengue Hemorrhagic Fever : Dengue Hemorrhagic Fever Also called Dengue Shock Syndrome (DSS), Resulting in Widespread bleeding Low blood pressure / shock due to bleeding or leaking blood vessels Organ failure

Dangerous symptoms of dengue : Dangerous symptoms of dengue Blood platelet count is less than 80,000 Bleeding from the nose or gums without any injury Unwell (lethargic/ drowsy/ breathing difficulty) Vomiting or poor feeding / drinking Severe abdominal pain and giddiness, as these can be signs of DHF / DSS.

Hepatitis Virus…Picorna virus : Hepatitis Virus…Picorna virus Inflammation of the liver Five main types A, B, C, D and E

Hepatitis A and E : Hepatitis A and E Typically caused by….. Ingestion of contaminated food or water.

Hepatitis B, C and D : Hepatitis B, C and D Infected body fluids E.g. from blood transfusions Or invasive medical procedures using contaminated equipment.

The symptoms of Hepatitis : The symptoms of Hepatitis Jaundice (yellowing of the skin and eyes), Dark urine, Extreme fatigue, Nausea, Vomiting and Abdominal pain.

Slide 72 : Hepatitis B .. also transmitted by sexual contact.

Hepatitis A : Hepatitis A Fastest spreading Contaminated food or drinking water. Every year, approximately 10 million people worldwide are infected with the virus. Incubation period ……28 days.

DREADFUL EBOLA VIRUSES : DREADFUL EBOLA VIRUSES ssRNA virus Causes haemorrhagic fever Severe bleeding Death Disease since 1976 in African subcontinent. Named after a river in Congo (formerly Zaire)

CHIKUNGUNYA VIRUS = BUGGY CREEK VIRUS : CHIKUNGUNYA VIRUS = BUGGY CREEK VIRUS Toga, Alpha virus with ssRNA Sudden severe headache Chills, Fever, Joint and muscular pains.

Slide 77 : Highly infective but not transmissible between people. Spread by Aedes aegypti mosquito

Slide 79 : Rabies = hydrophobia .. Rhabdovirus

Slide 80 : Rabies is a zoonotic disease . Through close contact With infected saliva (via bites or scratches). Present worldwide Most human deaths occur in Asia and Africa (more than 95%). Once symptoms of the disease develop, rabies is fatal.

Symptoms of Rabies : Symptoms of Rabies Flu-like, Including fever, Headache Fatigue Progress to involve the respiratory, gastrointestinal and/or central nervous systems. In the critical stage Signs of hyperactivity (furious rabies) or Paralysis (dumb rabies) dominate.

Slide 82 : In both furious and dumb rabies, Some paralysis eventually progresses to complete paralysis, Followed by coma and death in all cases, Usually due to breathing failure. Death may occur during the first seven days of illness.

Different kind of vaccination.. : Different kind of vaccination.. Unlike other immunizations, the rabies vaccine is administered after exposure to the virus. Rabies virus takes a comparatively long time to induce disease, a minimum of 10 days and in rare cases, up to a year. The length of the incubation period apparently depends on both the location of the wound - the farther from the brain, the longer the incubation - and the dose of virus received. Counting the first day of vaccine treatment as day 0, injections are administered on days 0, 3, 7, 14, and 28.

Poliomyelitis = Polio .. Enterovirus or Infantile Paralysis : Poliomyelitis = Polio .. Enterovirus or Infantile Paralysis 90% of polio infection affected individuals show no symptoms Can exhibit a range of symptoms if the virus enters the blood stream. Leads to Muscle weakness and Acute paralysis. Different types of paralysis may occur Spinal polio is the most common form, involving a leg.

In 1% of cases The virus enters the CNS infecting and destroying motor neurons. : In 1% of cases The virus enters the CNS infecting and destroying motor neurons. Polio

Polio Oral Vaccination : Polio Oral Vaccination Developed by J. Salk in 1952 and A. Sabin in 1962 Enhanced vaccination programs led by the WHO, UNICEF and Rotary could result in global eradication of the disease.

Encephalitis…Arboviruses..flavivirus : Encephalitis…Arboviruses..flavivirus An inflammation of the brain parenchyma, Distinct from meningitis, Though they coexist with signs and symptoms of meningeal inflammation, such as Photophobia, Headache, A stiff neck.

Slide 88 : Encephalitis

Slide 89 : Encephalitis

Japanese encephalitis : Japanese encephalitis Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia, with 30,000–50,000 cases reported annually. Incubation period of 5 to 15 days Case-fatality rates range from 0.3% to 60% and depends on the population and on age. Culex is a potential vector of the virus, common in Asia.

UNCONVENTIONAL INFECTIOUS VIRAL AGENTS : UNCONVENTIONAL INFECTIOUS VIRAL AGENTS PRIONS Particles of small amount of RNA Complexed with protein Derived from the host cell

PRIONS : PRIONS Stanley Prusiner discovered prions. Nobel Prize in 1997 Prions associated with…. 1. Scrapie 2. Creutzfeldt-Jacob disease (CJD) 3. Kuru 4. Chronic wasting disease (CWD)

Slide 94 : Prions Described as infectious proteins About 254 amino acids Mol. Wt. 50,000 Cause Parkinsonism Multiple sclerosis Kuru Creutzfeldt-Jacob disease (CJD) Senile dementia

Sigurdsson (1954) A veterinary pathologist First observed slowly progressing disease in sheep, such as Scrapie, Visna and Maedi Proposed the term ‘slow infection agent’ for the causative organism : Sigurdsson (1954) A veterinary pathologist First observed slowly progressing disease in sheep, such as Scrapie, Visna and Maedi Proposed the term ‘slow infection agent’ for the causative organism

Viroids : Viroids Protein-free fragments of single-stranded circular RNA Plant pathogens. Viroid was coined by Diener (1971)

Slide 97 : Viroid Low Mol. wt. …. 75,000 to 100,000 daltons. Infectious agent … first described in potato spindle tuber disease Also found to cause some other plant diseases.

Hit at … http://bisbio.inCall us at 09814016083, 09855516083 : email For all your Biology Problems UGC/CSIR NET Life Sciences AIPMT and State PMT SAT and GRE Advance Program Biology Civil Services Entrance to Biotechnology and Post graduate Sciences Entrance to BSc Nursing Hit at … http://bisbio.inCall us at 09814016083, 09855516083 amanbiswas60@gmail.com

Slide 99 : THE END