Related Research Articles
A human pathogen is a pathogen that causes disease in humans.
Progressive multifocal leukoencephalopathy (PML) is a rare and often fatal viral disease characterized by progressive damage (-pathy) or inflammation of the white matter (leuko-) of the brain (-encephalo-) at multiple locations (multifocal). It is caused by the JC virus, which is normally present and kept under control by the immune system. The JC virus is harmless except in cases of weakened immune systems. In general, PML has a mortality rate of 30–50% in the first few months, and those who survive can be left with varying degrees of neurological disabilities.
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disease, is an illness resulting from an infection.
Measles is a highly contagious infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than 40 °C (104 °F), cough, runny nose, and inflamed eyes. Small white spots known as Koplik's spots may form inside the mouth two or three days after the start of symptoms. A red, flat rash which usually starts on the face and then spreads to the rest of the body typically begins three to five days after the start of symptoms. Common complications include diarrhea, middle ear infection (7%), and pneumonia (6%). These occur in part due to measles-induced immunosuppression. Less commonly seizures, blindness, or inflammation of the brain may occur. Other names include morbilli, rubeola, red measles, and English measles. Both rubella, also known as German measles, and roseola are different diseases caused by unrelated viruses.
Incubation period is the time elapsed between exposure to a pathogenic organism, a chemical, or radiation, and when symptoms and signs are first apparent. In a typical infectious disease, the incubation period signifies the period taken by the multiplying organism to reach a threshold necessary to produce symptoms in the host.
Koch's postulates are four criteria designed to establish a causal relationship between a microbe and a disease. The postulates were formulated by Robert Koch and Friedrich Loeffler in 1884, based on earlier concepts described by Jakob Henle, and the statements were refined and published by Koch in 1890. Koch applied the postulates to describe the etiology of cholera and tuberculosis, both of which are now ascribed to bacteria. The postulates have been controversially generalized to other diseases. More modern concepts in microbial pathogenesis cannot be examined using Koch's postulates, including viruses and asymptomatic carriers. They have largely been supplanted by other criteria such as the Bradford Hill criteria for infectious disease causality in modern public health and the Molecular Koch's postulates for microbial pathogenesis.
The spread of HIV/AIDS has affected millions of people worldwide; AIDS is considered a pandemic. The World Health Organization (WHO) estimated that in 2016 there were 36.7 million people worldwide living with HIV/AIDS, with 1.8 million new HIV infections per year and 1 million deaths due to AIDS. Misconceptions about HIV and AIDS arise from several different sources, from simple ignorance and misunderstandings about scientific knowledge regarding HIV infections and the cause of AIDS to misinformation propagated by individuals and groups with ideological stances that deny a causative relationship between HIV infection and the development of AIDS. Below is a list and explanations of some common misconceptions and their rebuttals.
An opportunistic infection is an infection caused by pathogens that take advantage of an opportunity not normally available. These opportunities can stem from a variety of sources, such as a weakened immune system, an altered microbiome, or breached integumentary barriers. Many of these pathogens do not necessarily cause disease in a healthy host that has a non-compromised immune system, and can, in some cases, act as commensals until the balance of the immune system is disrupted. Opportunistic infections can also be attributed to pathogens which cause mild illness in healthy individuals but lead to more serious illness when given the opportunity to take advantage of an immunocompromised host.
Following infection with HIV-1, the rate of clinical disease progression varies between individuals. Factors such as host susceptibility, genetics and immune function, health care and co-infections as well as viral genetic variability may affect the rate of progression to the point of needing to take medication in order not to develop AIDS.
Subacute sclerosing panencephalitis (SSPE)—also known as Dawson disease—is a rare form of chronic, progressive brain inflammation caused by slow infection with certain defective strains of hypermutated measles virus. The condition primarily affects children, teens, and young adults. It has been estimated that about 2 in 10,000 people who get measles will eventually develop SSPE. However, a 2016 study estimated that the rate for unvaccinated infants under 15 months was as high as 1 in 609. No cure for SSPE exists, and the condition is almost always fatal. SSPE should not be confused with acute disseminated encephalomyelitis, which can also be caused by the measles virus, but has a very different timing and course.
Virus latency is the ability of a pathogenic virus to lie dormant within a cell, denoted as the lysogenic part of the viral life cycle. A latent viral infection is a type of persistent viral infection which is distinguished from a chronic viral infection. Latency is the phase in certain viruses' life cycles in which, after initial infection, proliferation of virus particles ceases. However, the viral genome is not eradicated. The virus can reactivate and begin producing large amounts of viral progeny without the host becoming reinfected by new outside virus, and stays within the host indefinitely.
A neurotropic virus is a virus that is capable of infecting nerve tissue.
The Central Nervous System controls most of the functions of the body and mind. It comprises the brain, spinal cord and the nerve fibers that branch off to all parts of the body. The Central Nervous System viral diseases are caused by viruses that attack the CNS. Existing and emerging viral CNS infections are major sources of human morbidity and mortality. Virus infections usually begin in the peripheral tissues, and can invade the mammalian system by spreading into the peripheral nervous system and more rarely the CNS. CNS is protected by effective immune responses and multi-layer barriers, but some viruses enter with high-efficiency through the bloodstream and some by directly infecting the nerves that innervate the tissues. Most viruses that enter can be opportunistic and accidental pathogens, but some like herpes viruses and rabies virus have evolved in time to enter the nervous system efficiently, by exploiting the neuronal cell biology. While acute viral diseases come on quickly, chronic viral conditions have long incubation periods inside the body. Their symptoms develop slowly and follow a progressive, fatal course.
Progressive rubella panencephalitis (PRP) is a neurological disorder which may occur in a child with congenital rubella. It is a slow viral infection of the brain characterized by chronic encephalitis, usually manifesting between 8–19 years of age. It is believed to be due to a persistence or reactivation of rubella virus infection.
In biology, a pathogen in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ.
HIV is commonly transmitted via unprotected sexual activity, blood transfusions, hypodermic needles, and from mother to child. Upon acquisition of the virus, the virus replicates inside and kills T helper cells, which are required for almost all adaptive immune responses. There is an initial period of influenza-like illness, and then a latent, asymptomatic phase. When the CD4 lymphocyte count falls below 200 cells/ml of blood, the HIV host has progressed to AIDS, a condition characterized by deficiency in cell-mediated immunity and the resulting increased susceptibility to opportunistic infections and certain forms of cancer.
The stages of HIV infection are acute infection, latency and AIDS. Acute infection lasts for several weeks and may include symptoms such as fever, swollen lymph nodes, inflammation of the throat, rash, muscle pain, malaise, and mouth and esophageal sores. The latency stage involves few or no symptoms and can last anywhere from two weeks to twenty years or more, depending on the individual. AIDS, the final stage of HIV infection, is defined by low CD4+ T cell counts, various opportunistic infections, cancers and other conditions.
HIV/AIDS research includes all medical research that attempts to prevent, treat, or cure HIV/AIDS, as well as fundamental research about the nature of HIV as an infectious agent and AIDS as the disease caused by HIV.
Sharon Ruth Lewin, FRACP, FAHMS is the inaugural Director of the Peter Doherty Institute for Infection and Immunity. She is also a Professor of Medicine at The University of Melbourne and a National Health and Medical Research Council (NHMRC) Practitioner Fellow. As an infectious diseases physician and basic scientist, her laboratory focuses on basic, translational and clinical research aimed at finding a cure for HIV and understanding the interaction between HIV and hepatitis B virus. Her laboratory is funded by the NHMRC, the National Institutes of Health, The Wellcome Trust, the American Foundation for AIDS Research and multiple commercial partnerships. She is also the Chief Investigator of a NHMRC Centre of Research Excellence (CRE), The Australian Partnership for Preparedness Research on Infectious Diseases Emergencies (APPRISE) that aims to bring together Australia’s leading experts in clinical, laboratory and public health research to address the key components required for a rapid and effective emergency response to infectious diseases.
References
- ↑ "About HIV/AIDS | HIV Basics | HIV/AIDS". U.S. Centers for Disease Control and Prevention. 2019-02-28. Retrieved 2019-03-05.
- ↑ "Subacute Sclerosing Panencephalitis". PubMed Health. National Center for Biotechnology Information, U.S. National Library of Medicine. Archived from the original on 25 February 2014. Retrieved 10 February 2012.
- ↑ Roodman GD, Windle JJ (February 2005). "Paget disease of bone". The Journal of Clinical Investigation. 115 (2): 200–208. doi:10.1172/JCI24281. PMC 546434 . PMID 15690073.
- ↑ Levinson W, Chin-Hong P, Joyce EA, Nussbaum J, Schwartz B, eds. (2020). "Slow Viruses & Prions.". Medical Microbiology & Immunology: A Guide to Clinical Infectious Diseases (16th ed.). McGraw Hill.
- ↑ Bocharov G, Ludewig B, Bertoletti A, Klenerman P, Junt T, Krebs P, et al. (March 2004). "Underwhelming the immune response: effect of slow virus growth on CD8+-T-lymphocyte responses". Journal of Virology. 78 (5): 2247–2254. doi:10.1128/jvi.78.5.2247-2254.2004. PMC 369240 . PMID 14963121.
- 1 2 3 Pinto M, Dobson S (January 2014). "BK and JC virus: a review". The Journal of Infection. 68 (Suppl 1): S2–S8. doi:10.1016/j.jinf.2013.09.009. PMID 24119828.
- ↑ Bradford BM, Mabbott NA (December 2012). "Prion disease and the innate immune system". Viruses. 4 (12): 3389–3419. doi: 10.3390/v4123389 . PMC 3528271 . PMID 23342365.
- ↑ Haridy R (2022-02-25). "The new science linking cancer, schizophrenia and MS to viral infections". New Atlas. Retrieved 2022-02-28.
- ↑ Garg RK (February 2002). "Subacute sclerosing panencephalitis". Postgraduate Medical Journal. 78 (916): 63–70. doi:10.1136/pmj.78.916.63. PMC 1742261 . PMID 11807185.
- ↑ Kuroda Y, Matsui M (April 1997). "[Progressive rubella panencephalitis]". Nihon Rinsho. Japanese Journal of Clinical Medicine (in Japanese). 55 (4): 922–925. PMID 9103895.
- ↑ Hemachudha T, Ugolini G, Wacharapluesadee S, Sungkarat W, Shuangshoti S, Laothamatas J (May 2013). "Human rabies: neuropathogenesis, diagnosis, and management". The Lancet. Neurology. 12 (5): 498–513. doi:10.1016/S1474-4422(13)70038-3. PMID 23602163. S2CID 1798889.
- ↑ Soong TR, Milner Jr DA (2015). "Human Papillomavirus Infection". In Milner Jr DA, Pecora N, Solomon I, Soong TR (eds.). Diagnostic Pathology: Infectious Diseases. Elsevier Health Sciences. p. 40. ISBN 978-0-323-40037-4. Archived from the original on 11 September 2017.