Lecture 9 - Biology 301 Infectious Disease & Society...

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Unformatted text preview: Biology 301 Infectious Disease & Society Hepatitis A, B, C What is Hepatitis? “Hepatitis means inflammation of the liver. Toxins, certain drugs, some diseases, heavy alcohol use, and bacterial and viral infections can all cause hepatitis. Hepatitis is also the name of a family of viral infections that affect the liver; the most common types in the United States are hepatitis A, hepatitis B, and hepatitis C.” http://www.cdc.gov/hepatitis/HepatitisB.htm Hepatitis A, B, C What are the causative agents of Hepatitis (A,B, and C)? Hepatits A is caused by the Hepatitis A virus (HAV) Hepatits B is caused by the Hepatitis B virus (HBV) Hepatits C is caused by the Hepatitis C virus (HCV) Hepatitis B Virion http://virus.stanford.edu/hepadna/Pictures.html Hepatitis A, B, C What occurs when someone is infected with a Hepatitis virus (What are the signs and symptoms)? Signs Signs Signs and Symptoms of Hepatitis A and Symptoms of Hepatitis B and Symptoms of Hepatitis C Hepatitis B Focus on Hepatitis B How does Hepatitis B virus destroy the liver? (What is the mechanism of pathogenesis?) HBV Note Lifecycle Animation – HBV_Lifecycle.exe that like HIV, HBV utilizes reverse transcriptase (an enzyme that makes DNA from RNA) –Typically in cells, RNA is made from DNA. Hepatitis B How is Hepatitis B transmitted? “The virus is transmitted through blood and infected bodily fluids. This can occur through direct blood-to-blood contact, unprotected sex, use of unsterile needles, and from an infected woman to her newborn during the delivery process.” http://www.hepb.org/hepb/about_hepatitis_b.htm Hepatitis B How do we treat Hepatitis B infection? 7 Drugs approved by the FDA for Hepatitis B infection Hepatitis Vaccine Animation Current Status of HepaVaxx b and other Hep B drugs Hepatitis B Resources for dealing with Hepatitis B. CDC Resources Hepatitis B Foundation Meningitis What is meningitis? “Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs.” http://en.wikipedia.org/wiki/Meningitis Meningitis What can cause the condition of meningitis? Meningitis Bacteria Viruses Some (the condition) can be caused by: Fungi Certain drugs Some Protozoans Meningitis The causes of meningitis that are of concern in this course are: Bacterial meningitis Meningococcal Pneumococcal Viral Meningitis Viral Meningitis How frequently does viral meningitis occur and what causes viral meningitis? half of the viral cases in the United States are due to common intestinal viruses, or enteroviruses. These viruses are shed in the feces and in discharges from the mouth and nose. Most people who become infected with the virus contract it through handto-mouth contact.” http://www.ehealthmd.com/library/meningitis/mg_causes.html#viral “Approximately Viral Meningitis What are the symptoms of viral meningitis? Viral ("aseptic") meningitis is serious but rarely fatal in persons with normal immune systems. Usually, the symptoms last from 7 to 10 days and the patient recovers completely. Often, the symptoms of viral meningitis and bacterial meningitis are the same. http://www.cdc.gov/meningitis/viral/viral-faqs.htm#2 Viral Meningitis Signs and Symptoms (For Adults) Fever and chills Headache Vomiting Stiff neck (patient may not be able to curl up in bed with nose to knees) Irritability and drowsiness Eyes that are sensitive to light Delirium and confusion (uncommon) Seizures (rare) Coma (rare) http://www.ehealthmd.com/library/meningitis/MG_symptoms.html Viral Meningitis How do we treat viral meningitis? “No specific treatment for viral meningitis exists at this time. Most patients completely recover on their own. Doctors often will recommend bed rest, plenty of fluids, and medicine to relieve fever and headache.” http://www.cdc.gov/meningitis/viral/viral-faqs.htm#4 Bacterial Meningitis Bacterial meningitis is usually more severe than the viral meningitis. Bacterial meningitis can have serious after-effects, such as brain damage, hearing loss, limb amputation, or learning disabilities. The leading causes of this type of meningitis are the bacteria: Streptococcus pneumoniae (pneumococcus) Neisseria meningitidis (usually referred to as "meningococcus" and the disease it causes as meningococcal disease) http://www.cdc.gov/meningitis/bacterial/index.htm Neisseria meningitidis http://bioinfo.bact.wisc.edu/themicrobialworld/mmeningitis.html http://www.kimicontrol.com/edu-e.html Bacterial Meningitis Differentiating “Before the causes of bacterial meningitis. the 1990s, Hib was the leading cause of bacterial meningitis, but new vaccines being given to children as part of their routine immunizations have reduced the occurrence of serious Hib disease.” “Today, Neisseria meningitidis and Streptococcus pneumoniae are the leading causes of bacterial meningitis.” “Meningitis caused by Neisseria meningitidis is also called MENINGOCOCCAL MENINGITIS. Meningitis caused by Streptococcus pneumoniae is called PNEUMOCOCCAL MENINGITIS” http://www.dhpe.org/infect/Bacmeningitis.html Bacterial Meningitis What are the signs and symptoms of bacterial meningitis? CDC Factsheet Bacterial Meningitis How is bacterial meningitis transmitted? droplets (coughing, sneezing, kissing) Respiratory “However, sometimes the bacteria that cause meningitis have spread to other people who have had close or prolonged contact with a patient with meningitis caused by Neisseria meningitidis (also called meningococcal meningitis)” http://www.cdc.gov/meningitis/bacterial/faqs.htm Bacterial Meningitis How do we treat bacterial meningitis? “Bacterial meningitis can be treated with a number of effective antibiotics. It is important, however, that treatment be started early in the course of the disease. Appropriate antibiotic treatment of most common types of bacterial meningitis should reduce the risk of dying from meningitis to below 15%, although the risk is higher among the elderly.” http://www.cdc.gov/meningitis/bacterial/faqs.htm Bacterial Meningitis Antibiotics used for bacterial meningitis (at early stages): Ampicillin Cefotaxime Ceftriaxone Gentamicin sulfate Penicillin G (benzylpenicillin) Vancomycin Bacterial Meningitis Vaccines for bacterial meningitis: Influenzae type b vaccine disease vaccines disease vaccine 1 disease vaccine 2 Haemophilus Meningococcal Pneumococcal Pneumococcal Human Papillomavirus What is HPV (in the context of diease)? “Genital HPV infection is a sexually transmitted disease (STD) that is caused by human papillomavirus (HPV). Human papillomavirus is the name of a group of viruses that includes more than 100 different strains or types. More than 30 of these viruses are sexually transmitted...” http://www.cdc.gov/STD/HPV/ Human Papillomavirus What are the signs and symptoms of Genital HPV infection? “Most people with HPV do not develop symptoms or health problems. But sometimes, certain types of HPV can cause genital warts in men and women. Other HPV types can cause cervical cancer and other less common cancers, such as cancers of the vulva, vagina, anus, and penis. The types of HPV that can cause genital warts are not the same as the types that can cause cancer.” http://www.cdc.gov/std/HPV/STDFact-HPV.htm Human Papillomavirus HPV concerns: Genital Warts – “They can appear on the vulva, in or around the vagina or anus, on the cervix, and on the penis, scrotum, groin, or thigh. Warts may appear within weeks or months after sexual contact with an infected person. Or, they may not appear at all. If left untreated, genital warts may go away, remain unchanged, or increase in size or number. They will not turn into cancer.” http://www.cdc.gov/std/HPV/STDFact-HPV.htm Human Papillomavirus HPV concerns: “Cervical cancer - does not have symptoms until it is quite advanced. For this reason, it is important for women to get screened regularly for cervical cancer.” “HPV-related cancers - such as cancers of the vulva, vagina, anus and penis, also may not have signs or symptoms until they are advanced.” http://www.cdc.gov/std/HPV/STDFact-HPV.htm Human Papillomavirus What is the causative agent of Genital HPV infections? Human Papillomavirus – non-enveloped (the capsid surrounding the virus is not covered by a lipid membrane), icosahedral morphology, Double stranded DNA genome. Principles of Molecular Virology, Cann, A. 2005 Human Papillomavirus http://hpvstudy.bol.ucla.edu/hpvbug.htm http://www.path.cam.ac.uk/pages/stanley-sterling/image/ Human Papillomavirus How is HPV transmitted? “Genital HPV is passed on through genital contact, most often during vaginal and anal sex. A person can have HPV even if years have passed since he or she had sex. Most infected persons do not realize they are infected or that they are passing the virus to a sex partner.” “Very rarely, a pregnant woman with genital HPV can pass HPV to her baby during vaginal delivery. In these cases, the child may develop warts in the throat or voice box – a condition called recurrent respiratory papillomatosis (RRP).” http://www.cdc.gov/std/HPV/STDFact-HPV.htm Human Papillomavirus “During sexual activity, desquamated cells are deposited on the epithelial surfaces of the sex partner. The mechanical stress of the sexual activity may break open some of the DCCs, while others may remain damaged but otherwise relatively intact. As virions are released from the DCCs, a focal, high multiplicity of infection occurs due to the concentrated release on a small area of genital epithelium.” Transmission of Human Papillomavirus Type 11 Infection by Desquamated Cornified Cells Janine T. Bryan* and Darron R. Brown*,²,1 Human Papillomavirus How “A is a Genital HPV infection treated? vaccine can now protect females from the four types of HPV that cause most cervical cancers and genital warts. The vaccine is recommended for 11 and 12 year-old girls. It is also recommended for girls and women age 13 through 26 who have not yet been vaccinated or completed the vaccine series.” http://www.cdc.gov/std/HPV/STDFact-HPV.htm#howget Human Papillomavirus CDC Factsheet on HPV Vaccine website for Gardasil Merck Lyme Disease What is Lyme Disease? “Lyme disease is [an emerging infectious disease] caused by the bacterium Borrelia burgdorferi (gram negative spirochete) and is transmitted to humans by the bite of infected blacklegged ticks.” http://www.cdc.gov/ncidod/dvbid/lyme/index.htm Lyme Disease What is the causative agent of Lyme Disease? “Borrelia burgdorferi…is a spirochete. Spirochetes are a group of phylogenetically - distinct bacteria that have a unique mode of motility by means of axial filaments (endoflagella). Spirochetes are widespread in viscous environments and they are found in the intestinal tracts of animals and the oral cavity of humans.” http://www.textbookofbacteriology.net/Lyme.html Lyme Disease Structural “The note about Borrelia burgdorferi spirochetes are not classified as either Grampositive or Gram-negative. When Borrelia burgdorferi is Gram-stained, the cells stain a weak Gram-negative by default, as safranin is the last dye used. It does have an outer membrane that contains an LPS-like substance, an inner membrane, and a periplasmic space which contains a layer of peptidoglycan…therefore, it has a Gram-negative bacterial type cell wall, despite its staining characteristics.” http://www.textbookofbacteriology.net/Lyme.html Lyme Disease How do we stain spirochetes to see them? 1. 2. “Impregnating the spirochetes with a dye or metallic ion and rendering it visible against a light background.” “Rendering the unstained spirochetes visible by making the background black with staining, e. g., by using India ink preparations.” http://archderm.ama-assn.org/cgi/content/summary/67/2/210 Lyme Disease http://www.wadsworth.org/databank/hirez/hechemy2.gif http://upload.wikimedia.org/wikipedia/commons/1/15/Borrelia_burgdorferi-cropped.jpg Lyme Disease How is Lyme Disease transmitted? “The Lyme disease bacterium, Borrelia burgdorferi, normally lives in mice, squirrels and other small animals. It is transmitted among these animals – and to humans – through the bites of certain species of ticks.” http://www.cdc.gov/ncidod/dvbid/lyme/index.htm Lyme Disease Connecticut Agricultural Experiment Station Ti Lyme Disease How does Borrelia burgdorferi cause Lyme disease? “An inflammatory response occurs as the pathogen migrates in waves from the initial site of infection, causing a target shaped rash.” “A distinctive feature of the rash is that it gradually expands over a period of several days, reaching up to 12 inches (30 cm) across” http://www.cdc.gov/ncidod/dvbid/lyme/ld_humandisease_symptoms.htm Lyme Disease How does Borrelia burgdorferi cause Lyme disease? “Systemic effects are caused by Borrelia initiating a series of events that stimulate release of tumor necrosis factor and interleukin-1…both products stimulate endotoxic shock.” Outbreak, R. Anderson 2006 Lyme Disease How does Borrelia burgdorferi cause Lyme disease / Signs and Symptoms? also experience symptoms of fatigue, chills, fever, headache, and muscle and joint aches, and swollen lymph nodes. In some cases, these may be the only symptoms of infection.” – damage due to immune hypersensitivity http://www.cdc.gov/ncidod/dvbid/lyme/ld_humandisease_symptoms.htm “Patients Lyme Disease How does Borrelia burgdorferi cause Lyme disease / Signs and Symptoms? “After several months, approximately 60% of patients with untreated infection will begin to have intermittent bouts of arthritis, with severe joint pain and swelling. Large joints are most often affected, particularly the knees. In addition, up to 5% of untreated patients may develop chronic neurological complaints months to years after infection.” http://www.cdc.gov/ncidod/dvbid/lyme/ld_humandisease_symptoms.htm Lyme Disease How is Lyme Disease treated? “most patients can be cured with a few weeks of antibiotics taken by mouth. Antibiotics commonly used for oral treatment include doxycycline, amoxicillin, or cefuroxime axetil. Patients with certain neurological or cardiac forms of illness may require intravenous treatment with drugs such as ceftriaxone or penicillin” http://www.cdc.gov/ncidod/dvbid/lyme/ld_humandisease_treatment.htm Lyme Disease How is Lyme Disease treated? “Patients treated with antibiotics in the early stages of the infection usually recover rapidly and completely. A few patients, particularly those diagnosed with later stages of disease, may have persistent or recurrent symptoms.” http://www.cdc.gov/ncidod/dvbid/lyme/ld_humandisease_treatment.htm Lyme Disease Lyme Disease Summary Animation Project 4 ...
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This note was uploaded on 04/29/2009 for the course BIOL 301 taught by Professor Kocache,m during the Spring '08 term at George Mason.

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