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Coinfection
Coinfection is the simultaneous infection of a host by multiple pathogen species. In virology, coinfection includes simultaneous infection of a single cell by two or more virus particles. An example is the coinfection of liver cells with hepatitis B virus and hepatitis D virus, which can arise incrementally by initial infection followed by superinfection. Global prevalence or incidence of coinfection among humans is unknown, but it is thought to be commonplace, sometimes more common than single infection. Coinfection with helminths affects around 800 million people worldwide. Coinfection is of particular human health importance because pathogen species can interact within the host. The net effect of coinfection on human health is thought to be negative. Interactions can have either positive or negative effects on other parasites. Under positive parasite interactions, disease transmission and progression are enhanced and this is also known as syndemism. Negative pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infection
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. Infections can be caused by a wide range of pathogens, most prominently bacteria and viruses. Hosts can fight infections using their immune system. Mammalian hosts react to infections with an innate response, often involving inflammation, followed by an adaptive response. Specific medications used to treat infections include antibiotics, antivirals, antifungals, antiprotozoals, and antihelminthics. Infectious diseases resulted in 9.2 million deaths in 2013 (about 17% of all deaths). The branch of medicine that focuses on infections is referred to as infectious disease. Types Infections are caused by infectious agents ( pathogens) including: * Bacteria (e.g. ''Mycobacterium tube ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syndemic
A syndemic or synergistic epidemic is the aggregation of two or more concurrent or sequential epidemics or disease clusters in a population with biological interactions, which exacerbate the prognosis and burden of disease. The term was developed by Merrill Singer in the early 1990s to call attention to the synergistic nature of the health and social problems facing the poor and underserved. Syndemics develop under health disparity, caused by poverty, stress, or structural violence and are studied by epidemiologists and medical anthropologists concerned with public health, community health and the effects of social conditions on health. The syndemic approach departs from the biomedical approach to diseases to diagnostically isolate, study, and treat diseases as distinct entities separate from other diseases and independent of social contexts. Definition A syndemic is a synergistic epidemic. The term was developed by Merrill Singer in the mid-1990s, culminating in a 2009 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatitis B Virus
''Hepatitis B virus'' (HBV) is a partially double-stranded DNA virus, a species of the genus '' Orthohepadnavirus'' and a member of the '' Hepadnaviridae'' family of viruses. This virus causes the disease hepatitis B. Disease Despite there being a vaccine to prevent Hepatitis B, HBV remains a global health problem. Hepatitis B can be acute and later become chronic, leading to other diseases and health conditions. In addition to causing hepatitis, infection with HBV can lead to cirrhosis and hepatocellular carcinoma. It has also been suggested that it may increase the risk of pancreatic cancer. Roles in disease Viral infection by ''Hepatitis B virus'' (HBV) causes many hepatocyte changes due to the direct action of a protein encoded by the virus, HBx, and to indirect changes due to a large increase in intracellular reactive oxygen species (ROS) after infection. HBx appears to dysregulate a number of cellular pathways. HBx causes dysregulation in part by binding to genomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superinfection
A superinfection is a second infection superimposed on an earlier one, especially by a different microbial agent of exogenous or endogenous origin, that is resistant to the treatment being used against the first infection. Examples of this in bacteriology are the overgrowth of endogenous ''Clostridium difficile'' that occurs following treatment with a broad-spectrum antibiotic, and pneumonia or sepsis from ''Pseudomonas aeruginosa'' in some immunocompromised patients. In virology, the definition is slightly different. Superinfection is the process by which a cell that has previously been infected by one virus gets co-infected with a different strain of the virus, or another virus, at a later point in time. In some cases viral superinfections may be resistant to the antiviral drug or drugs that were being used to treat the original infection. Viral superinfections may also be less susceptible to the host's immune response. In Zika virus infection, there is some evidence that prim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virulence
Virulence is a pathogen's or microorganism's ability to cause damage to a host. In most, especially in animal systems, virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism—its ability to cause disease—is determined by its virulence factors. In the specific context of gene for gene systems, often in plants, virulence refers to a pathogen's ability to infect a resistant host. The noun ''virulence'' derives from the adjective ''virulent'', meaning disease severity. The word ''virulent'' derives from the Latin word ''virulentus'', meaning "a poisoned wound" or "full of poison." From an ecological standpoint, virulence is the loss of fitness induced by a parasite upon its host. Virulence can be understood in terms of proximate causes—those specific traits of the pathogen that help make the host ill—and ultimate causes—the evolutionary pressures that lead to virulent traits occurring in a pathogen strain. Virulent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colonisation (biology)
Colonisation or colonization is the process in biology by which a species spreads to new areas. Colonisation often refers to ''successful'' immigration where a population becomes integrated into an ecological community, having resisted initial local extinction. In ecology, it is represented by the symbol ''λ'' (lowercase lambda) to denote the long-term intrinsic growth rate of a population. One classic scientific model in biogeography posits that species must continue to colonize new areas through its life cycle (called a ''taxon cycle'') in order to achieve longevity. Accordingly, colonisation and extinction are key components of island biogeography, a theory that has many applications in ecology, such as metapopulations. Scale Colonisation occurs on several scales. In the most basic form, as biofilm in the formation of communities of microorganisms on surfaces. In small scales such as colonising new sites, perhaps as a result of environmental change. And on larger s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonas Aeruginosa
''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic– facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. aeruginosa'' is a multidrug resistant pathogen recognized for its ubiquity, its intrinsically advanced antibiotic resistance mechanisms, and its association with serious illnesses – hospital-acquired infections such as ventilator-associated pneumonia and various sepsis syndromes. The organism is considered opportunistic insofar as serious infection often occurs during existing diseases or conditions – most notably cystic fibrosis and traumatic burns. It generally affects the immunocompromised but can also infect the immunocompetent as in hot tub folliculitis. Treatment of ''P. aeruginosa'' infections can be difficult due to its natural resistance to antibiotics. When more advanced antibiotic drug regimens are needed adverse eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphylococcus Aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe that can grow without the need for oxygen. Although ''S. aureus'' usually acts as a commensal of the human microbiota, it can also become an opportunistic pathogen, being a common cause of skin infections including abscesses, respiratory infections such as sinusitis, and food poisoning. Pathogenic strains often promote infections by producing virulence factors such as potent protein toxins, and the expression of a cell-surface protein that binds and inactivates antibodies. ''S. aureus'' is one of the leading pathogens for deaths associated with antimicrobial resistance and the emergence of antibiotic-resistant strains, such as methicillin-resistant ''S. aureu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infectious Disease (medical Specialty)
Infectious diseases or ID, also known as infectiology, is a medical specialty dealing with the diagnosis and treatment of infections. An infectious diseases specialist's practice consists of managing nosocomial ( healthcare-acquired) infections or community-acquired infections and is historically associated with hygiene, epidemiology, clinical microbiology, travel medicine and tropical medicine. Scope Infectious diseases specialists typically serve as consultants to other physicians in cases of complex infections, and often manage patients with HIV/AIDS and other forms of immunodeficiency. Although many common infections are treated by physicians without formal expertise in infectious diseases, specialists may be consulted for cases where an infection is difficult to diagnose or manage. They may also be asked to help determine the cause of a fever of unknown origin. Specialists in infectious diseases can practice both in hospitals (inpatient) and clinics (outpatient). In ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission (medicine)
In medicine, public health, and biology, transmission is the passing of a pathogen causing communicable disease from an infected host individual or group to a particular individual or group, regardless of whether the other individual was previously infected. The term strictly refers to the transmission of microorganisms directly from one individual to another by one or more of the following means: * airborne transmission – very small dry and wet particles that stay in the air for long periods of time allowing airborne contamination even after the departure of the host. Particle size 5 μm. * direct physical contact – touching an infected individual, including sexual contact * indirect physical contact – usually by touching a contaminated surface, including soil ( fomite) * fecal–oral transmission – usually from unwashed hands, contaminated food or water sources due to lack of sanitation and hygiene, an important transmission route in pediatrics, veterinary medicine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Interactions
In ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species (intraspecific interactions), or of different species (interspecific interactions). These effects may be short-term, like pollination and predation, or long-term; both often strongly influence the evolution of the species involved. A long-term interaction is called a symbiosis. Symbioses range from mutualism, beneficial to both partners, to competition, harmful to both partners. Interactions can be indirect, through intermediaries such as shared resources or common enemies. This type of relationship can be shown by net effect based on individual effects on both organisms arising out of relationship. Several recent studies have suggested non-trophic species interactions such as habitat modification and mutualisms can be important determinants of food web structures. However, it remains unclear whether these findings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexually Transmitted Disease
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal diseases, are infections that are Transmission (medicine), spread by Human sexual activity, sexual activity, especially Sexual intercourse, vaginal intercourse, anal sex, and oral sex. STIs often do not initially cause symptoms, which results in a risk of passing the infection on to others. Symptoms and signs of STIs may include vaginal discharge, penile discharge, genital ulcers, ulcers on or around the genitals, and pelvic pain. Some STIs can cause infertility. Bacterial STIs include Chlamydia infection, chlamydia, gonorrhea, and syphilis. Viral STIs include genital herpes, HIV/AIDS, and genital warts. Parasitic STIs include trichomoniasis. STI diagnostic tests are usually easily available in the developed world, but they are often unavailable in the developing world. Some vaccinations may also decrease the risk of certain infections including Hepa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
