Lecture 10 - Biology 301 Biology Infectious Disease& Society HIV HIV What HIV HIV is HIV(Human Immunodeficiency Virus is a an enveloped virus

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Unformatted text preview: Biology 301 Biology Infectious Disease & Society HIV HIV What HIV HIV is HIV? (Human Immunodeficiency Virus) is a an enveloped virus with a polyhedral protein capsid and single stranded RNA as its genetic information. as http://www.stanford.edu/group/virus/retro/2005gongishmail/hiv1.jpg http://www.wellesley.edu/Chemistry/Chem101/hiv/maturhiv.gif HIV HIV What What does HIV infect? (What are the viruses target cells?) target cells that can be infected by HIV are CD4+ (CD4 positive), meaning that they have the CD4 receptor molecule on their surface, but not every CD4+ cell is a target of HIV. The most common target cells are helper T-cells and macrophages. In the central nervous system, HIV infects macrophages and also microglial cells. It can also target dendritic cells, found mostly in the lymphatic system (Knight et al., 1990).” lymphatic http://en.wikipedia.org/wiki/User:Hob/HIV_life_cycle Knight, S. C., Macatonia, S. E. and Patterson, S. (1990) HIV I infection of dendritic cells. Int Rev Immunol. 6,163-75 PMID 2152500 “All All Unique Fluorescence staining illustrating HIV-1 virions collecting on a macrophage. http://commons.wikimedia.org/wiki/File:HIV_on_macrophage.png HIV-1 virions budding off of a macrophage http://www.iayork.com/Images/2008/1-14-07/HIV_Budding_EM_NCI.png HIV HIV HIV Lifecycle Animation 1 ( YouTube) HIV YouTube) HIV Lifecycle Animation 2 (Sumanas Inc.) HIV HIV What What is the disease associated with/caused by an HIV infection? with/caused (Acquired Immune Deficiency cquired mmune eficiency Syndrome) is the disease/condition that yndrome) can result from an HIV infection. AIDS AIDS AIDS What is AIDS? According to the CDC, you have AIDS if you are According infected with HIV and have at least one of infected the following: the 1) A CD4+ T-cell count below 200 cells/µl (or a 1) CD4+ T-cell percentage of total lymphocytes of less than 14%) of 2) You have one of the following defining 2) illnesses: illnesses: http://www.cdc.gov/mmwr/preview/mmwrhtml/00018871.htm Candidiasis of bronchi, trachea, or lungs Candidiasis Candidiasis, esophageal Candidiasis, Cervical cancer, invasive * Cervical Coccidioidomycosis, disseminated or extrapulmonary Coccidioidomycosis, Cryptococcosis, extrapulmonary Cryptococcosis, Cryptosporidiosis, chronic intestinal (greater than 1 month's duration) Cryptosporidiosis, Cytomegalovirus disease (other than liver, spleen, or nodes) Cytomegalovirus Cytomegalovirus retinitis (with loss of vision) Cytomegalovirus Encephalopathy, HIV-related Encephalopathy, Herpes simplex: chronic ulcer(s) (greater than 1 month's duration); or bronchitis, pneumonitis, or Herpes esophagitis Histoplasmosis, disseminated or extrapulmonary Histoplasmosis, Isosporiasis, chronic intestinal (greater than 1 month's duration) Isosporiasis, Kaposi's sarcoma Kaposi's Lymphoma, Burkitt's (or equivalent term) Lymphoma, Lymphoma, immunoblastic (or equivalent term) Lymphoma, Lymphoma, primary, of brain Lymphoma, Mycobacterium avium complex or M. kansasii, disseminated or extrapulmonary Mycobacterium Mycobacterium tuberculosis, any site (pulmonary * or extrapulmonary) Mycobacterium Mycobacterium, other species or unidentified species, disseminated or extrapulmonary Mycobacterium, Pneumocystis carinii pneumonia Pneumocystis Pneumonia, recurrent * Pneumonia, Progressive multifocal leukoencephalopathy Progressive Salmonella septicemia, recurrent Salmonella Toxoplasmosis of brain Toxoplasmosis Wasting syndrome due to HIV Wasting Added in the 1993 expansion of the AIDS surveillance case definition. http://www.cdc.gov/mmwr/preview/mmwrhtml/00018871.htm AIDS AIDS 1993 Revised Classification System for HIV Infe AIDS AIDS What What is AIDS? –Understanding CD4+T Cell counts counts your test reports CD4% = 34%, that means that 34% of your lymphocytes were CD4 cells. This percentage is more stable than the number of CD4 cells. The normal range is between 20% and 40%. A CD4 percentage below 14% indicates serious immune damage. It is a sign of AIDS in people with HIV infection. AIDS http://www.aids.org/factSheets/124-T-Cell-Tests.html “If If Mononucleosis Mononucleosis What An An is Mononucleosis? infectious disease typically caused by the Epstein Barr virus (a similar condition can be caused by some other agents) caused “Laboratory testing may be needed to Laboratory differentiate EBV infections from mononucleosisdifferentiate llike illnesses induced by cytomegalovirus, ike adenovirus, or Toxoplasma gondii” Toxoplasma Mononucleosis gets its name from the increased Mononucleosis number of monocytes that are present in the blood of an infected person. blood http://www.cdc.gov/ncidod/diseases/ebv.htm Epstein-Barr Virus Epstein-Barr What is EBV? “Epstein-Barr virus, frequently referred to Epstein-Barr as EBV, is a member of the herpesvirus family and one of the most common human viruses” human It is an enveloped virus with a polyhedral It protein capsid and double stranded DNA as its genetic material. as http://www.cdc.gov/ncidod/diseases/ebv.htm Epstein-Barr Virus Epstein-Barr How is EBV transmitted? “EBV EBV is transmitted via intimate contact with body secretions, primarily oropharyngeal secretions. EBV infects the B cells in the oropharyngeal epithelium. The organism may also be shed from the uterine cervix, implicating the role of genital transmission in some cases. On rare occasion, EBV is spread via blood transfusion.” transfusion.” http://emedicine.medscape.com/article/222040-overview Epstein-Barr Virus Epstein-Barr What “EBV EBV are the target cells of EBV? infects and multiplies in the epithelial cells of the oropharynx.” of “EBV [also] invades B cells by means of their EBV CD21 receptor, and 18-24 hours later EBV antigens are detectable within the lymphocyte nucleus. During the acute phase, as many as 20% of the circulating B cells will show EBV antigens” antigens” http://www.kcom.edu/faculty/chamberlain/website/lectures/lecture/mono.htm Mononucleosis Mononucleosis What are the symptoms of Mono? “Symptoms of infectious mononucleosis are fever, sore throat, and swollen lymph glands. Sometimes, a swollen spleen or liver involvement may develop. Heart problems or involvement of the central nervous system occurs only rarely, and infectious mononucleosis is almost never fatal” is http://www.cdc.gov/ncidod/diseases/ebv.htm Mononucleosis Mononucleosis How is mono treated? “There There is no specific treatment for infectious mononucleosis, other than treating the mononucleosis symptoms. No antiviral drugs or vaccines are available. Some physicians have prescribed a 5available. day course of steroids to control the swelling of day the throat and tonsils. The use of steroids has also been reported to decrease the overall length and severity of illness, but these reports have not been published.” have http://www.cdc.gov/ncidod/diseases/ebv.htm Mononucleosis Mononucleosis How is mono treated? “Acyclovir Acyclovir and ganciclovir may reduce EBV shedding but are ineffective clinically” http://emedicine.medscape.com/article/222040-treatment Healthy vs. Infected Monocyte Healthy http://profelis.org/neu/ap2/4166_final_sampler.html http://www.medscape.com/content/2003/00/45/83/458301/458301_fig.html West Nile Virus West What is West Nile Virus? “West West Nile virus (WNV) is a potentially serious illness. Experts believe WNV is established as a seasonal epidemic in North America that flares up in the summer and continues into the fall.” http://www.cdc.gov/ncidod/dvbid/westnile/wnv_factsheet.htm West Nile Virus West What is West Nile Virus? “West West Nile virus (or WNV) is a virus of the family Flaviviridae. Part of the Japanese encephalitis (JE) antigenic complex of viruses, it is found in both tropical and temperate regions. It mainly infects birds, but is known to infect humans, horses, dogs, cats, bats, chipmunks, skunks, squirrels, and domestic rabbits. The main route of human infection is through the bite of an infected mosquito. infected http://www.cdc.gov/ncidod/dvbid/westnile/wnv_factsheet.htm West Nile Virus West “West West Nile Virus has three different effects on humans. The first is an asymptomatic infection; the second is a mild febrile syndrome termed West Nile Fever; the third is a neuroinvasive disease termed West Nile meningitis or encephalitis. In many infected individuals the ratio between the three states is roughly 110:30:1.” 110:30:1.” Sejvar JJ, Haddad MB, Tierney BC, et al (2003). "Neurologic manifestations and outcome of West Nile virus infection". JAMA 290 (4): 511–5. doi:10.1001/jama.290.4.511. PMID 12876094. Tsai TF, Popovici F, Cernescu C, Campbell GL, Nedelcu NI (1998). "West Nile encephalitis epidemic in southeastern Romania". Lancet 352 (9130): 767–71. doi:10.1016/S0140-6736(98)03538-7. PMID 9737281 West Nile Virus West What [West [West is West Nile Virus? Nile Virus] has single stranded RNA as its genetic material and also has an icosahedral (20-sided) protein capsid with an envelope. an http://www.cdc.gov/ncidod/dvbid/westnile/wnv_factsheet.htm West Nile Virus West http://en.wikipedia.org/wiki/File:NIAID-west-Nile.jpg West Nile Virus (TEM) West http://www.equidblog.com/articles/another-category/west-nile-virus-1/ West Nile Virus West What What are the target cells of West Nile Virus? Virus? “Virus may initially infect local fibroblasts, vascular endothelial cells, or cells of the reticuloendothelial system”. “This extra-neural infection leads to viremia, which is the probable route for invasion of the central nervous system (neurons)”. Gea-Banacloche J, Johnson RT, Bagic A, Butman JA, Murray PR, Agrawal AG. National Cancer Institute, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA. [email protected] What are the symptoms of West Nile Virus? Serious Symptoms in a Few People. About one in 150 About people infected with WNV will develop severe illness. The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. These symptoms may last several weeks, and neurological effects may be permanent. effects Milder Symptoms in Some People. Up to 20 percent of the Up people who become infected have symptoms such as fever, headache, and body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms can last for as short as a few days, though even healthy people have become sick for several weeks. No Symptoms in Most People. Approximately 80 percent Approximately of people (about 4 out of 5) who are infected with WNV will not show any symptoms at all. West Nile Virus West How is West Nile Virus Treated? “There There is no specific treatment for WNV infection. In cases with milder symptoms, people experience symptoms such as fever and aches that pass on their own, although even healthy people have become sick for several weeks. In more severe cases, people usually need to go to the hospital where they can receive supportive treatment including intravenous fluids, help with breathing and nursing care.” breathing http://www.cdc.gov/ncidod/dvbid/westnile/wnv_factsheet.htm West Nile Virus West CDC Homepage for West Nile Virus Information Strep Throat Strep What is Strep Throat? “Strep Strep throat is a bacterial infection in the throat and the tonsils. The throat gets irritated and inflamed, causing a sudden, severe sore throat.” severe http://www.webmd.com/a-to-z-guides/strep-throat-topic-overview Strep Throat Strep What causes strep throat? “Strep Strep throat is caused by Group A Streptococcus bacteria. It is the most Streptococcus common bacterial infection of the throat.” common http://www.nlm.nih.gov/MEDLINEPLUS/ency/article/000639.htm Strep Throat Strep What “The The causes Strep Throat? group A streptococcus bacterium (Streptococcus pyogenes, or GAS) is a form of Streptococcus bacteria responsible for most cases of streptococcal illness. Other types (B, C, D, and G) may also cause infection. Several virulence factors contribute to the pathogenesis of GAS, such as M protein, hemolysins, and extracellular enzymes” extracellular http://en.wikipedia.org/wiki/Group_A_streptococcal_infection Streptococcus pyogenes Streptococcus “Streptococcus pyogenes is a spherical grampositive bacteria that grows in long chains and is positive the cause of Group A streptococcal infections.[1] S. pyogenes displays streptococcal group A antigen on its cell wall.” antigen “S. pyogenes typically produces large zones of S. beta-hemolysis (the complete disruption of erythrocytes and the release of hemoglobin) when cultured on blood agar plates and are therefore also called Group A (beta-hemolytic) Streptococcus” Streptococcus” http://en.wikipedia.org/wiki/Streptococcus_pyogenes Streptococcus pyogenes Streptococcus (SEM) http://blogs.iwcc.edu/syshra http://www.ncl.ac.uk/facilities/microscopy/assets/photos/macroWM.jpg Beta-hemolysis Beta-hemolysis http://student.ccbcmd.edu/courses/bio141/labmanua/lab14/abg_asm.html Strep Throat Strep What are the signs and symptoms of Strep Throat? Severe and sudden sore throat without coughing, Severe sneezing, or other cold symptoms. Pain or difficulty with swallowing. Pain Fever over 101F. Lower fevers may indicate a viral Fever infection and not strep. Swollen lymph nodes in the neck. Swollen White or yellow spots or coating on the throat and White tonsils. Bright red throat or dark red spots on the roof of the Bright mouth at the back near the throat. Swollen tonsils, although this symptom may also be Swollen caused by a viral infection. caused http://www.webmd.com/a-to-z-guides/strep-throat-symptoms Streptococcus pyogenes Streptococcus How How does Streptococcus pyogenes cause disease (Strep Throat)? disease capsule of S. pyogenes is non antigenic since it is composed of hyaluronic acid, which is chemically similar to that of host connective tissue. This allows the bacterium to hide its own antigens and to go unrecognized as antigenic by its host” its http://www.textbookofbacteriology.net/streptococcus_2.html “The The Streptococcus pyogenes Streptococcus How How does Streptococcus pyogenes cause disease (Strep Throat)? disease the most part, streptococcal invasins and protein toxins interact with mammalian blood and tissue components in ways that kill host cells (ex. betakill hemolysis) and provoke a damaging hemolysis) inflammatory response” inflammatory http://www.textbookofbacteriology.net/streptococcus_2.html “For For Strep Throat Strep How The The is Strep Throat treated? antibiotics amoxicillin, cephalexin, erythromycin, and penicillin are most often prescribed to destroy the bacterial agent. Penicillin is often the first choice (unless you are allergic to it). allergic Various other OTC medications may be used to Various alleviate pain or provide other symptom relief. alleviate Chicken Pox Chicken What “A is chicken pox? disease caused by infection with the disease Varicella Zoster Virus, which causes fever and an itchy rash” http://www.cdc.gov/vaccines/vpd-vac/varicella/in-short-adult.htm Chicken Pox Chicken What is Varicella Zoster Virus? “Varicella zoster virus (VZV) is one of Varicella eight herpes viruses known to infect humans (and other vertebrates). It commonly causes chicken-pox in children and both shingles and postherpetic neuralgia in adults.” neuralgia Steiner I, Kennedy PG, Pachner AR (2007). "The neurotropic herpes viruses: herpes simplex and varicella-zoster". Lancet Neurol 6 (11): 1015–28. Chicken Pox Chicken What The The is Varicella Zoster Virus? VZV virion has an icosahedral protein capsid surrounded by a lipid envelope and double-stranded DNA as its genetic material. material. Varicella Zoster Virus Varicella http://upload.wikimedia.org/wikipedia/commons/1/16/Varicella_(Chickenpox)_Virus_PHIL_1878_lores.jpg Varicella Zoster Virus Varicella How does VZV cause chicken pox? “The virus is transmitted by airborne viral particles shed The from the skin of an infected person. The new host breathes in the virus, which enters the mucous membrane in a person’s respiratory tract and begins to spread without its envelope from cell to cell.” spread “The virus invades T-cells of the blood and those T-cells The carry the virus to the skin. There, the virus can recreate its envelope because the top layer of the skin lacks the endosomal pathway that removes glycoproteins from the envelope.” envelope.” http://www.cumc.columbia.edu/news/in-vivo/Vol1_no7_apr15_02/varicella.html Varicella Zoster Virus Varicella How “As As does VZV cause chicken pox? the enveloped virus builds up, it creates the characteristic chickenpox rash. From there, the virus can aerosolize again and infect a new host. But enveloped viruses, which have mannose 6But phosphate in their glycoprotein envelope, can phosphate travel from the skin to sensory nerves.” travel “The varicella zoster virus is drawn to sensory The nerve cells by their mannose 6-phosphate receptors.” receptors.” http://www.cumc.columbia.edu/news/in-vivo/Vol1_no7_apr15_02/varicella.html Varicella Zoster Virus Varicella http://www.opt.indiana.edu/V543/Pathology543/graphics/infectdz/ID-04.jpg Varicella Zoster Virus Varicella Medical School Histopathology lecture on VZV le l Varicella Zoster Virus Varicella What What are the other potential threats of VZV infection? VZV can invade the nervous system and stay dormant for many years, only to reactivate and return to the skin as shingles, or zoster” “…Varicella, Varicella, http://www.cumc.columbia.edu/news/in-vivo/Vol1_no7_apr15_02/varicella.html Varicella Zoster Virus Varicella What What are the other potential threats of VZV infection? infection? VZV infection results in chickenpox (varicella), which may rarely result in complications including encephalitis or pneumonia. Even when clinical symptoms of chickenpox have resolved, VZV remains dormant in the nervous system” dormant http://www.cumc.columbia.edu/news/in-vivo/Vol1_no7_apr15_02/varicella.html “Primary Primary How “For For do we treat chicken pox? most health children, chickenpox symptoms can be controlled with soothing baths or antihistamines to decrease itching. Acetaminophen may help control fever, headache, or muscle pain. headache, “A prescription drug called acyclovir is FDA prescription approved to treat the symptoms of chickenpox in persons older than age 2. The drug should help reduce the severity of chickenpox symptoms” chickenpox http://www.nlm.nih.gov/medlineplus/ency/article/001972.htm Chicken Pox Vaccine Chicken What “The The is the chicken pox vaccine? chickenpox vaccine is a live attenuated vaccine. This means the live, disease-producing virus was modified, or weakened, in the laboratory to produce an organism that can grow and produce immunity in the body without causing illness.” illness.” http://www.vaccineinformation.org/varicel/qandavax.asp Chicken Pox Vaccine Chicken CDC Factsheet on the Chicken Pox Vaccine ...
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This note was uploaded on 01/19/2010 for the course BIOL 301 taught by Professor Kocache,m during the Spring '08 term at George Mason.

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