Infection
Infection | |
---|---|
fungal, prion |
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.[1] 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.[2] Hosts can fight infections using their immune systems. Mammalian hosts react to infections with an innate response, often involving inflammation, followed by an adaptive response.
Specific
Types
Infections are caused by infectious agents (pathogens) including:
- Bacteria (e.g. Mycobacterium tuberculosis, Staphylococcus aureus, Escherichia coli, Clostridium botulinum, and Salmonella spp.)
- Severe acute respiratory syndrome coronavirus 2)
- Fungi, further subclassified into:
- Pneumocystis species; and dermatophytes, a group of organisms causing infection of skin and other superficial structures in humans.[6]
- Basidiomycota, including the human-pathogenic genus Cryptococcus.[7]
- Parasites, which are usually divided into:[8]
- Unicellular organisms (e.g. malaria, Toxoplasma, Babesia)
- Macroparasitesschistosomes). Diseases caused by helminthsare sometimes termed infestations, but are sometimes called infections.
- lice, can also cause human disease, which conceptually are similar to infections, but invasion of a human or animal body by these macroparasites is usually termed infestation.
- Prions (although they do not secrete toxins)
Signs and symptoms
The signs and symptoms of an infection depend on the type of disease. Some signs of infection affect the whole body generally, such as fatigue, loss of appetite, weight loss, fevers, night sweats, chills, aches and pains. Others are specific to individual body parts, such as skin rashes, coughing, or a runny nose.[10]
In certain cases, infectious diseases may be asymptomatic for much or even all of their course in a given host. In the latter case, the disease may only be defined as a "disease" (which by definition means an illness) in hosts who secondarily become ill after contact with an asymptomatic carrier. An infection is not synonymous with an infectious disease, as some infections do not cause illness in a host.[11]
Bacterial or viral
As bacterial and viral infections can both cause the same kinds of symptoms, it can be difficult to distinguish which is the cause of a specific infection.[12] Distinguishing the two is important, since viral infections cannot be cured by antibiotics whereas bacterial infections can.[13]
Characteristic | Viral infection | Bacterial infection |
---|---|---|
Typical symptoms | In general, viral infections are systemic. This means they involve many different parts of the body or more than one body system at the same time; i.e. a runny nose, sinus congestion, cough, body aches etc. They can be local at times as in viral conjunctivitis or "pink eye" and herpes. Only a few viral infections are painful, like herpes. The pain of viral infections is often described as itchy or burning.[12] | The classic symptoms of a bacterial infection are localized redness, heat, swelling and pain. One of the hallmarks of a bacterial infection is local pain, pain that is in a specific part of the body. For example, if a cut occurs and is infected with bacteria, pain occurs at the site of the infection. Bacterial throat pain is often characterized by more pain on one side of the throat. An |
Cause | Pathogenic viruses |
Pathogenic bacteria |
Pathophysiology
There is a general chain of events that applies to infections, sometimes called the chain of infection[15] or transmission chain. The chain of events involves several steps – which include the infectious agent, reservoir, entering a susceptible host, exit and transmission to new hosts. Each of the links must be present in a chronological order for an infection to develop. Understanding these steps helps health care workers target the infection and prevent it from occurring in the first place.[16]
Colonization
Infection begins when an organism successfully enters the body, grows and multiplies. This is referred to as colonization. Most humans are not easily infected. Those with compromised or weakened immune systems have an increased susceptibility to chronic or persistent infections. Individuals who have a suppressed
The variables involved in the outcome of a host becoming inoculated by a pathogen and the ultimate outcome include:
- the route of entry of the pathogen and the access to host regions that it gains
- the intrinsic virulence of the particular organism
- the quantity or load of the initial inoculant
- the immune status of the host being colonized
As an example, several
An interesting fact that gas chromatography–mass spectrometry, 16S ribosomal RNA analysis, omics, and other advanced technologies have made more apparent to humans in recent decades is that microbial colonization is very common even in environments that humans think of as being nearly sterile. Because it is normal to have bacterial colonization, it is difficult to know which chronic wounds can be classified as infected and how much risk of progression exists. Despite the huge number of wounds seen in clinical practice, there are limited quality data for evaluated symptoms and signs. A review of chronic wounds in the Journal of the American Medical Association's "Rational Clinical Examination Series" quantified the importance of increased pain as an indicator of infection.[23] The review showed that the most useful finding is an increase in the level of pain [likelihood ratio (LR) range, 11–20] makes infection much more likely, but the absence of pain (negative likelihood ratio range, 0.64–0.88) does not rule out infection (summary LR 0.64–0.88).
Disease
Disease can arise if the host's protective immune mechanisms are compromised and the organism inflicts damage on the host. Microorganisms can cause tissue damage by releasing a variety of toxins or destructive enzymes. For example, Clostridium tetani releases a toxin that paralyzes muscles, and staphylococcus releases toxins that produce shock and sepsis. Not all infectious agents cause disease in all hosts. For example, less than 5% of individuals infected with polio develop disease.[24] On the other hand, some infectious agents are highly virulent. The prion causing mad cow disease and Creutzfeldt–Jakob disease invariably kills all animals and people that are infected.[25]
Persistent infections occur because the body is unable to clear the organism after the initial infection. Persistent infections are characterized by the continual presence of the infectious organism, often as latent infection with occasional recurrent relapses of active infection. There are some viruses that can maintain a persistent infection by infecting different cells of the body. Some viruses once acquired never leave the body. A typical example is the herpes virus, which tends to hide in nerves and become reactivated when specific circumstances arise.[26]
Persistent infections cause millions of deaths globally each year.[27] Chronic infections by parasites account for a high morbidity and mortality in many underdeveloped countries.[28][29]
Transmission
For infecting organisms to survive and repeat the infection cycle in other hosts, they (or their progeny) must leave an existing reservoir and cause infection elsewhere. Infection transmission can take place via many potential routes:[30]
- Droplet contact, also known as the respiratory route, and the resultant infection can be termed airborne disease. If an infected person coughs or sneezes on another person the microorganisms, suspended in warm, moist droplets, may enter the body through the nose, mouth or eye surfaces.
- Fecal-oral transmission, wherein foodstuffs or water become contaminated (by people not washing their hands before preparing food, or untreated sewage being released into a drinking water supply) and the people who eat and drink them become infected. Common fecal-oral transmitted pathogens include Vibrio cholerae, Giardia species, rotaviruses, Entamoeba histolytica, Escherichia coli, and tape worms.[31] Most of these pathogens cause gastroenteritis.
- Sexual transmission, with the result being called sexually transmitted infection.
- Oral transmission, diseases that are transmitted primarily by oral means may be caught through direct oral contact such as kissing, or by indirect contact such as by sharing a drinking glass or a cigarette.
- Transmission by direct contact, Some diseases that are transmissible by direct contact include athlete's foot, impetigo and warts.
- Vehicle transmission, transmission by an inanimate reservoir (food, water, soil).[32]
- Vertical transmission, directly from the mother to an embryo, fetus or baby during pregnancy or childbirth. It can occur as a result of a pre-existing infection or one acquired during pregnancy.
- transplantationof infected material.
- Vector-borne transmission, transmitted by a
The relationship between virulence versus transmissibility is complex; with studies have shown that there were no clear relationship between the two.[34][35] There is still a small number of evidence that partially suggests a link between virulence and transmissibility.[36][37][38]
Diagnosis
Diagnosis of infectious disease sometimes involves identifying an infectious agent either directly or indirectly.
Diagnosis of infectious disease is nearly always initiated by medical history and physical examination. More detailed identification techniques involve the culture of infectious agents isolated from a patient. Culture allows identification of infectious organisms by examining their microscopic features, by detecting the presence of substances produced by pathogens, and by directly identifying an organism by its genotype.[40]
Many infectious organisms are identified without culture and microscopy. This is especially true for viruses, which cannot grow in culture. For some suspected pathogens, doctors may conduct tests that examine a patient's blood or other body fluids for antigens or antibodies that indicate presence of a specific pathogen that the doctor suspects.[40]
Other techniques (such as
The benefits of identification, however, are often greatly outweighed by the cost, as often there is no specific treatment, the cause is obvious, or the outcome of an infection is likely to be
Symptomatic diagnostics
The diagnosis is aided by the presenting symptoms in any individual with an infectious disease, yet it usually needs additional diagnostic techniques to confirm the suspicion. Some signs are specifically characteristic and indicative of a disease and are called pathognomonic signs; but these are rare. Not all infections are symptomatic.[43]
In children the presence of
Microbial culture
Many diagnostic approaches depend on
In the absence of suitable plate culture techniques, some microbes require culture within live animals. Bacteria such as
Microscopy
Another principal tool in the diagnosis of infectious disease is
Other microscopic procedures may also aid in identifying infectious agents. Almost all cells readily stain with a number of basic
Biochemical tests
Biochemical tests used in the identification of infectious agents include the detection of
The isolation of
Complex serological techniques have been developed into what are known as
Instrumentation can be used to read extremely small signals created by secondary reactions linked to the antibody – antigen binding. Instrumentation can control sampling, reagent use, reaction times, signal detection, calculation of results, and data management to yield a cost-effective automated process for diagnosis of infectious disease.
PCR-based diagnostics
Technologies based upon the
Thus, the technological ability to detect any infectious agent rapidly and specifically are currently available. The only remaining blockades to the use of PCR as a standard tool of diagnosis are in its cost and application, neither of which is insurmountable. The diagnosis of a few diseases will not benefit from the development of PCR methods, such as some of the clostridial diseases (tetanus and botulism). These diseases are fundamentally biological poisonings by relatively small numbers of infectious bacteria that produce extremely potent neurotoxins. A significant proliferation of the infectious agent does not occur, this limits the ability of PCR to detect the presence of any bacteria.[53]
Metagenomic sequencing
Given the wide range of bacterial, viral, fungal, protozoal, and helminthic pathogens that cause debilitating and life-threatening illnesses, the ability to quickly identify the cause of infection is important yet often challenging. For example, more than half of cases of
Metagenomic sequencing could prove especially useful for diagnosis when the patient is
Indication of tests
There is usually an
Classification
Subclinical versus clinical (latent versus apparent)
Symptomatic infections are apparent and clinical, whereas an infection that is active but does not produce noticeable symptoms may be called inapparent, silent, subclinical, or occult. An infection that is inactive or dormant is called a latent infection.[54] An example of a latent bacterial infection is latent tuberculosis. Some viral infections can also be latent, examples of latent viral infections are any of those from the Herpesviridae family.[55]
The word infection can
Course of infection
Different terms are used to describe how and where infections present over time. In an acute infection, symptoms develop rapidly; its course can either be rapid or protracted. In chronic infection, symptoms usually develop gradually over weeks or months and are slow to resolve.
Primary versus opportunistic
Among the many varieties of
Primary pathogens
Primary pathogens cause disease as a result of their presence or activity within the normal, healthy host, and their intrinsic virulence (the severity of the disease they cause) is, in part, a necessary consequence of their need to reproduce and spread. Many of the most common primary pathogens of humans only infect humans, however, many serious diseases are caused by organisms acquired from the environment or that infect non-human hosts.[61]
Opportunistic pathogens
Opportunistic pathogens can cause an infectious disease in a host with depressed resistance (
Secondary infection
While a primary infection can practically be viewed as the root cause of an individual's current health problem, a secondary infection is a sequela or complication of that root cause. For example, an infection due to a burn or penetrating trauma (the root cause) is a secondary infection. Primary pathogens often cause primary infection and often cause secondary infection. Usually, opportunistic infections are viewed as secondary infections (because immunodeficiency or injury was the predisposing factor).[60]
Other types of infection
Other types of infection consist of mixed,
Infectious or not
One manner of proving that a given disease is infectious, is to satisfy
However, Koch's postulates cannot usually be tested in modern practice for ethical reasons. Proving them would require experimental infection of a healthy individual with a
Contagiousness
Infectious diseases are sometimes called contagious diseases when they are easily transmitted by contact with an ill person or their secretions (e.g., influenza). Thus, a contagious disease is a subset of infectious disease that is especially infective or easily transmitted. Other types of infectious, transmissible, or communicable diseases with more specialized routes of infection, such as vector transmission or sexual transmission, are usually not regarded as "contagious", and often do not require medical isolation (sometimes loosely called quarantine) of those affected. However, this specialized connotation of the word "contagious" and "contagious disease" (easy transmissibility) is not always respected in popular use. Infectious diseases are commonly transmitted from person to person through direct contact. The types of contact are through person to person and droplet spread. Indirect contact such as airborne transmission, contaminated objects, food and drinking water, animal person contact, animal reservoirs, insect bites, and environmental reservoirs are another way infectious diseases are transmitted.[65]
By anatomic location
Infections can be classified by the anatomic location or organ system infected, including:[citation needed]
- Urinary tract infection
- Skin infection
- Respiratory tract infection
- Odontogenic infection (an infection that originates within a tooth or in the closely surrounding tissues)
- Vaginal infections
- Intra-amniotic infection
In addition, locations of inflammation where infection is the most common cause include pneumonia, meningitis and salpingitis.[citation needed]
Prevention
Techniques like hand washing, wearing gowns, and wearing face masks can help prevent infections from being passed from one person to another. Aseptic technique was introduced in medicine and surgery in the late 19th century and greatly reduced the incidence of infections caused by surgery. Frequent hand washing remains the most important defense against the spread of unwanted organisms.[67] There are other forms of prevention such as avoiding the use of illicit drugs, using a condom, wearing gloves, and having a healthy lifestyle with a balanced diet and regular exercise. Cooking foods well and avoiding foods that have been left outside for a long time is also important.[citation needed]
- tissue/skin
- disinfectants, which destroy microorganisms found on non-living objects.
- prophylacticwhen given as prevention rather as treatment of infection. However, long term use of antibiotics leads to resistance of bacteria. While humans do not become immune to antibiotics, the bacteria does. Thus, avoiding using antibiotics longer than necessary helps preventing bacteria from forming mutations that aide in antibiotic resistance.
One of the ways to prevent or slow down the transmission of infectious diseases is to recognize the different characteristics of various diseases.
Another effective way to decrease the transmission rate of infectious diseases is to recognize the effects of
A general method to prevent transmission of
In cases where infection is merely suspected, individuals may be
Immunity
Infection with most pathogens does not result in death of the host and the offending organism is ultimately cleared after the symptoms of the disease have waned.
- a direct effect upon a pathogen, such as antibody-initiated complement-dependent bacteriolysis, opsonoization, phagocytosis and killing, as occurs for some bacteria,
- neutralization of viruses so that these organisms cannot enter cells,
- or by T lymphocytes, which will kill a cell parasitized by a microorganism.
The immune system response to a microorganism often causes symptoms such as a high fever and inflammation, and has the potential to be more devastating than direct damage caused by a microbe.[11]
Resistance to infection (
Immune resistance to an infectious disease requires a critical level of either antigen-specific antibodies and/or T cells when the host encounters the pathogen. Some individuals develop natural
Host genetic factors
The organism that is the target of an infecting action of a specific infectious agent is called the host. The host harbouring an agent that is in a mature or sexually active stage phase is called the definitive host. The intermediate host comes in contact during the larvae stage. A host can be anything living and can attain to asexual and sexual reproduction.[74] The clearance of the pathogens, either treatment-induced or spontaneous, it can be influenced by the genetic variants carried by the individual patients. For instance, for genotype 1
Treatments
When infection attacks the body,
Not all infections require treatment, and for many self-limiting infections the treatment may cause more side-effects than benefits. Antimicrobial stewardship is the concept that healthcare providers should treat an infection with an antimicrobial that specifically works well for the target pathogen for the shortest amount of time and to only treat when there is a known or highly suspected pathogen that will respond to the medication.[79]
Susceptibility to infection
Pandemics such as COVID-19 show that people dramatically differ in their susceptibility to infection. This may be because of general health, age, or their immune status, e.g. when they have been infected previously. However, it also has become clear that there are genetic factor which determine susceptibility to infection. For instance, up to 40% of SARS-CoV-2 infections may be asymptomatic, suggesting that many people are naturally protected from disease.[80] Large genetic studies have defined risk factors for severe SARS-CoV-2 infections, and genome sequences from 659 patients with severe COVID-19 revealed genetic variants that appear to be associated with life-threatening disease. One gene identified in these studies is type I interferon (IFN). Autoantibodies against type I IFNs were found in up to 13.7% of patients with life-threatening COVID-19, indicating that a complex interaction between genetics and the immune system is important for natural resistance to Covid.[81]
Similarly, mutations in the ERAP2 gene, encoding endoplasmic reticulum aminopeptidase 2, seem to increase the susceptibility to the plague, the disease caused by an infection with the bacteria Yersinia pestis. People who inherited two copies of a complete variant of the gene were twice as likely to have survived the plague as those who inherited two copies of a truncated variant.[82]
Susceptibility also determined the epidemiology of infection, given that different populations have different genetic and environmental conditions that affect infections.
Epidemiology
In 2010, about 10 million people died of infectious diseases.[84]
The
Rank | Cause of death | Deaths 2002 (in millions) |
Percentage of all deaths |
Deaths 1993 (in millions) |
1993 Rank |
---|---|---|---|---|---|
N/A | All infectious diseases | 14.7 | 25.9% | 16.4 | 32.2% |
1 | Lower respiratory infections[87] | 3.9 | 6.9% | 4.1 | 1 |
2 | AIDS |
2.8 | 4.9% | 0.7 | 7 |
3 | Diarrheal diseases[88] | 1.8 | 3.2% | 3.0 | 2 |
4 | Tuberculosis (TB) | 1.6 | 2.7% | 2.7 | 3 |
5 | Malaria | 1.3 | 2.2% | 2.0 | 4 |
6 | Measles | 0.6 | 1.1% | 1.1 | 5 |
7 | Pertussis |
0.29 | 0.5% | 0.36 | 7 |
8 | Tetanus | 0.21 | 0.4% | 0.15 | 12 |
9 | Meningitis | 0.17 | 0.3% | 0.25 | 8 |
10 | Syphilis | 0.16 | 0.3% | 0.19 | 11 |
11 | Hepatitis B | 0.10 | 0.2% | 0.93 | 6 |
12–17 | Tropical diseases (6)[89] | 0.13 | 0.2% | 0.53 | 9, 10, 16–18 |
Note: Other causes of death include maternal and perinatal conditions (5.2%), nutritional deficiencies (0.9%), noncommunicable conditions (58.8%), and injuries (9.1%). |
The top three single agent/disease killers are
Historic pandemics
With their potential for unpredictable and explosive impacts, infectious diseases have been major actors in human history.[91] A pandemic (or global epidemic) is a disease that affects people over an extensive geographical area. For example:
- Plague of Justinian, from 541 to 542, killed between 50% and 60% of Europe's population.[92]
- The Black Death of 1347 to 1352 killed 25 million in Europe over five years. The plague reduced the old world population from an estimated 450 million to between 350 and 375 million in the 14th century.
- The introduction of smallpox, measles, and typhus to the areas of Central and South America by European explorers during the 15th and 16th centuries caused pandemics among the native inhabitants. Between 1518 and 1568 disease pandemics are said to have caused the population of Mexico to fall from 20 million to 3 million.[93]
- The first European influenza epidemic occurred between 1556 and 1560, with an estimated mortality rate of 20%.[93]
- Smallpox killed an estimated 60 million Europeans during the 18th century[94] (approximately 400,000 per year).[95] Up to 30% of those infected, including 80% of the children under 5 years of age, died from the disease, and one-third of the survivors went blind.[96]
- In the 19th century, tuberculosis killed an estimated one-quarter of the adult population of Europe;[97] by 1918 one in six deaths in France were still caused by TB.
- The Influenza Pandemic of 1918 (or the Spanish flu) killed 25–50 million people (about 2% of world population of 1.7 billion).[98] Today Influenza kills about 250,000 to 500,000 worldwide each year.
Emerging diseases
In most cases, microorganisms live in harmony with their hosts via mutual or commensal interactions. Diseases can emerge when existing parasites become pathogenic or when new pathogenic parasites enter a new host.
- parasite and host can lead to hosts becoming resistant to the parasites or the parasites may evolve greater virulence, leading to immunopathological disease.
- Human activity is involved with many environmental change enabling a parasite to occupy new niches. When that happens, a pathogen that had been confined to a remote habitat has a wider distribution and possibly a new host organism. Parasites jumping from nonhuman to human hosts are known as zoonoses. Under disease invasion, when a parasite invades a new host species, it may become pathogenic in the new host.[99]
Several human activities have led to the emergence of
:- Encroachment on wildlife habitats. The construction of new villages and housing developments in rural areas force animals to live in dense populations, creating opportunities for microbes to mutate and emerge.[101]
- Changes in agriculture. The introduction of new crops attracts new crop pests and the microbes they carry to farming communities, exposing people to unfamiliar diseases.
- The destruction of rain forests. As countries make use of their rain forests, by building roads through forests and clearing areas for settlement or commercial ventures, people encounter insects and other animals harboring previously unknown microorganisms.
- Uncontrolled urbanization. The rapid growth of cities in many developing countries tends to concentrate large numbers of people into crowded areas with poor sanitation. These conditions foster transmission of contagious diseases.
- Modern transport. Ships and other cargo carriers often harbor unintended "passengers", that can spread diseases to faraway destinations. While with international jet-airplane travel, people infected with a disease can carry it to distant lands, or home to their families, before their first symptoms appear.
Germ theory of disease
In Antiquity, the Greek historian Thucydides (c. 460 – c. 400 BCE) was the first person to write, in his account of the plague of Athens, that diseases could spread from an infected person to others.[102][103] In his On the Different Types of Fever (c. 175 AD), the Greco-Roman physician Galen speculated that plagues were spread by "certain seeds of plague", which were present in the air.[104] In the Sushruta Samhita, the ancient Indian physician Sushruta theorized: "Leprosy, fever, consumption, diseases of the eye, and other infectious diseases spread from one person to another by sexual union, physical contact, eating together, sleeping together, sitting together, and the use of same clothes, garlands and pastes."[105][106] This book has been dated to about the sixth century BC.[107]
A basic form of contagion theory was proposed by
When the
In the mid-19th century
Medical specialists
The
An infectious disease team may be alerted when:[citation needed]
- The disease has not been definitively diagnosed after an initial workup
- The patient is AIDS or after chemotherapy);
- The infectious agent is of an uncommon nature (e.g. tropical diseases);
- The disease has not responded to first line antibiotics;
- The disease might be dangerous to other patients, and the patient might have to be isolated
Society and culture
Several studies have reported associations between pathogen load in an area and human behavior. Higher pathogen load is associated with decreased size of ethnic and religious groups in an area. This may be due high pathogen load favoring avoidance of other groups, which may reduce pathogen transmission, or a high pathogen load preventing the creation of large settlements and armies that enforce a common culture. Higher pathogen load is also associated with more restricted sexual behavior, which may reduce pathogen transmission. It also associated with higher preferences for health and attractiveness in mates. Higher
Fossil record
Evidence of infection in
Outer space
A 2006
See also
- Biological hazard
- Blood-borne disease
- Coinfection
- Copenhagen Consensus
- Cordon sanitaire
- Epidemiological transition
- Foodborne illness
- Hospital-acquired infection
- Eradication of infectious diseases
- Infection control
- Isolation (health care)
- List of causes of death by rate
- List of diseases caused by insects
- List of infectious diseases
- Mathematical modelling of infectious disease
- Multiplicity of infection
- Neglected tropical diseases
- Sentinel surveillance
- Spillover infection
- Threshold host density
- Transmission (medicine)
- Vaccine-preventable diseases
- Waterborne diseases
References
- ^ "infection", The Free Dictionary, archived from the original on 2018-07-19, retrieved 2023-11-17
- from the original on 2021-04-13. Retrieved 2021-03-26.
- ^ "Antiprotozoal Drugs". TheFreeDictionary.com. Archived from the original on 2022-01-22. Retrieved 2022-04-22.
- PMID 25530442.
- ^ "Infectious Disease, Internal Medicine". Association of American Medical Colleges. Archived from the original on 2015-02-06. Retrieved 2015-08-20.
Infectious disease is the subspecialty of internal medicine dealing with the diagnosis and treatment of communicable diseases of all types, in all organs, and in all ages of patients.
- ^ "Types of Fungal Diseases". Centers for Disease Control and Prevention. 2019-06-27. Archived from the original on 2020-04-01. Retrieved 2019-12-09.
- from the original on 2020-06-19, retrieved 2019-12-09
- ^ "About Parasites". Centers for Disease Control and Prevention. 2019-02-25. Archived from the original on 2019-12-25. Retrieved 2019-12-09.
- JSTOR 656401.
- ^ "Runny Nose: Symptoms, Causes & Treatment". Cleveland Clinic. Archived from the original on 2022-05-10. Retrieved 2022-04-22.
- ^ ISBN 978-0-8385-8529-0.
- ^ a b c "NIPA - Bacteria - Bacterial vs. Viral infections". www.antibiotics-info.org. Archived from the original on 2023-11-10. Retrieved 2023-11-10.
- ISBN 978-1438126371.
- ^ "Infection". Rencare. Archived from the original on March 5, 2012. Retrieved 4 July 2013.
- ^ "Infection Cycle Symptoms and Treatment". Infection Cycle. Archived from the original on 2023-11-10. Retrieved 2023-11-10.
- ^ National Institutes of Health (US), Study BS (2007), "Understanding Emerging and Re-emerging Infectious Diseases", NIH Curriculum Supplement Series [Internet], National Institutes of Health (US), archived from the original on 2023-06-26, retrieved 2023-11-17
- from the original on 2016-04-25. Retrieved 2022-10-20.
- PMID 30231567.
- PMID 23778792.
- ^ "Bacterial Pathogenesis at Washington University". StudyBlue. St. Louis. Archived from the original on 2016-12-03. Retrieved 2016-12-02.
- ^ "Print Friendly". www.lifeextension.com. Archived from the original on 2016-12-02. Retrieved 2016-12-02.
- PMID 26016486.
- PMID 22318282.
- ^ "Polio: Questions and Answers" (PDF). immunize.org. Archived (PDF) from the original on 2022-10-09. Retrieved 9 July 2021.
- PMC 7149788.
- PMID 20577268.
- ^ "Chronic Infection Information". persistentinfection.net. Archived from the original on July 22, 2015. Retrieved 2010-01-14.
- PMID 26633705.
- from the original on 2016-10-10, retrieved 2021-08-13
- ^ "How Infections Spread". Centers for Disease Control and Prevention. 1 January 2016. Archived from the original on 2 June 2023. Retrieved 17 October 2021.
- ^ Intestinal Parasites and Infection Archived 2010-10-28 at the Wayback Machine fungusfocus.com – Retrieved on 2010-01-21
- ^ "Clinical Infectious Disease – Introduction". microbiologybook.org. Archived from the original on 2017-04-20. Retrieved 2017-04-19.
- ^ Pathogens and vectors Archived 2017-10-05 at the Wayback Machine. MetaPathogen.com.
- S2CID 85448255.
- from the original on 2022-12-04. Retrieved 2022-06-28.
- S2CID 86478171.
- PMID 18657880.
- PMID 28448507.
- PMC 7150340.
- ^ a b c Vazquez-Pertejo MT (October 2022). "Diagnosis of Infectious Disease - Infections". Merck Manuals Consumer Version. Archived from the original on 2024-01-02. Retrieved 2024-01-02.
- PMID 35505859.
- PMID 31142607.
- PMID 25614838.
- ^ S2CID 28014329.
- ISBN 978-0-323-67450-8.
- PMID 20855600.
- PMID 25793495.
- ISBN 978-0-323-67450-8.
- PMID 29748498.
- PMID 14532173.
- PMID 22572875.
- PMID 22779069.
- ^ PMID 24078518.
- ISBN 978-3-13-131991-3.
- PMID 24167660.
- PMID 24982790.
- from the original on 2020-04-14, retrieved 2020-01-23
- ^ ISBN 978-0-393-60257-9.
- ^ from the original on June 29, 2009. Retrieved 2013-11-27.
- ^ PMID 29135922.
- PMID 31027668.
- PMID 28515626.
- S2CID 201283277.
- S2CID 198135563.
- ^ Higurea & Pietrangelo 2016 [page needed]
- from the original on 2020-06-19. Retrieved 2017-03-26.
- ^ ""Generalized Infectious Cycle" Diagram Illustration". science.education.nih.gov. Archived from the original on 2009-09-24. Retrieved 2010-01-21.
- ^ ISBN 978-0-393-04142-2.
- ISBN 978-0-385-49522-6.
- ^ Programs NR, Normand J, Vlahov D, Moses LE (1995). The Effects of Needle Exchange Programs. National Academies Press (US). Archived from the original on 2021-03-10. Retrieved 2022-10-20.
- S2CID 16914744.
- ISBN 978-0-323-95389-4, archivedfrom the original on 2023-03-05, retrieved 2023-03-02
- ^ "Herd Immunity". Oxford Vaccine Group, University of Oxford. Archived from the original on 2 August 2019. Retrieved 11 August 2023.
- PMID 16476746.
- S2CID 1707096.
- PMID 19759533.
- PMID 25232278.
- ^ "Antibiotics: List of Common Antibiotics & Types". Drugs.com. Archived from the original on 2021-03-10. Retrieved 2020-11-10.
- S2CID 5487584.
- PMID 32491919.
- S2CID 225041500.
- PMID 36261521.
- ^ World Health Organization (February 2009). "Age-standardized DALYs per 100,000 by cause, and Member State, 2004". Archived from the original on 2021-08-28. Retrieved 2020-10-05.
- ^ "Could Ebola rank among the deadliest communicable diseases?". CBC News. 20 October 2014. Archived from the original on 27 August 2021. Retrieved 21 October 2014.
- ^ "The World Health Report (Annex Table 2)" (PDF). 2004. Archived (PDF) from the original on 2022-10-09.
- ^ "Table 5" (PDF). 1995. Archived (PDF) from the original on 2022-10-09.
- ^ Lower respiratory infections include various pneumonias, influenzas and acute bronchitis.
- ^ Diarrheal diseases are caused by many different organisms, including cholera, botulism, and E. coli to name a few. See also: Intestinal infectious diseases
- ^ Tropical diseases include Chagas disease, dengue fever, lymphatic filariasis, leishmaniasis, onchocerciasis, schistosomiasis and trypanosomiasis.
- ^ "WHO | The top 10 causes of death". WHO. Archived from the original on 2017-05-30. Retrieved 2015-09-24.
- PMID 22296079.
- ^ "Infectious and Epidemic Disease in History" Archived July 12, 2012, at archive.today
- ^ (PDF) from the original on 2016-03-03. Retrieved 2013-11-27.
- ^ "NCpedia | NCpedia". www.ncpedia.org. Archived from the original on 2023-03-28. Retrieved 2023-11-17.
- ^ Smallpox and Vaccinia. National Center for Biotechnology Information. Archived June 1, 2009, at the Wayback Machine
- S2CID 20357515.
- ^ Multidrug-Resistant "Tuberculosis". Centers for Disease Control and Prevention. Archived March 9, 2010, at the Wayback Machine
- ^ "Influenza of 1918 (Spanish Flu) and the US Navy". 20 February 2006. Archived from the original on 20 February 2006.
- ^ ISBN 978-1-55581-236-2.
- PMC 3903457.
- PMID 10642539.
- from the original on 2023-11-17. Retrieved 2023-11-17.
- ^ Thucydides, Crawley R (1914). History of the Peloponnesian War, done into English by Richard Crawley. Robarts - University of Toronto. London Dent. pp. 131–132.
- PMID 6339840.
- PMID 6399073.
- ^ Susruta, Bhishagratna KL (1907–1916). An English translation of the Sushruta samhita, based on original Sanskrit text. Edited and published by Kaviraj Kunja Lal Bhishagratna. With a full and comprehensive introd., translation of different readings, notes, comparative views, index, glossary and plates. Gerstein – University of Toronto. Calcutta.
- ^ Hoernle AF (1907). Studies in the medicine of ancient India. Gerstein – University of Toronto. Oxford : At the Clarendon Press.
- ISBN 978-1598842531.
- ISBN 978-1107067110.
- PMID 16373721.
- PMID 15309812.
- PMID 12411628.
- PMID 19683831.
- ^ Molnar, R. E., 2001, "Theropod paleopathology: a literature survey": In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 337–63.
- ^ Caspermeyer J (23 September 2007). "Space flight shown to alter ability of bacteria to cause disease". Arizona State University. Archived from the original on 14 September 2017. Retrieved 14 September 2017.
- PMID 23658630.
- ^ Dvorsky G (13 September 2017). "Alarming Study Indicates Why Certain Bacteria Are More Resistant to Drugs in Space". Gizmodo. Archived from the original on 14 September 2017. Retrieved 14 September 2017.
- ]
- PMID 11542695.
External links
- European Center for Disease Prevention and Control
- U.S. Centers for Disease Control and Prevention,
- Infectious Disease Society of America (IDSA)
- Vaccine Research Center Information concerning vaccine research clinical trials for Emerging and re-Emerging Infectious Diseases.
- Microbes & Infection (journal)