Diphtheria | |
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An adherent, dense, grey pseudomembrane covering the tonsils is classically seen in diphtheria. | |
Specialty | Infectious disease |
Symptoms | Sore throat, fever, barking cough [1] |
Complications | Myocarditis, Peripheral neuropathy, Proteinuria |
Usual onset | 2–5 days post-exposure [2] |
Causes | Corynebacterium diphtheriae (spread by direct contact and through the air) [2] |
Diagnostic method | Examination of throat, culture [1] |
Prevention | Diphtheria vaccine [2] |
Treatment | Antibiotics, tracheostomy [2] |
Prognosis | 5–10% risk of death |
Frequency | 4,500 (reported 2015) [3] |
Deaths | 2,100 (2015) [4] |
Diphtheria is an infection caused by the bacterium Corynebacterium diphtheriae . [2] Most infections are asymptomatic or have a mild clinical course, but in some outbreaks, the mortality rate approaches 10%. [1] Signs and symptoms may vary from mild to severe, [1] and usually start two to five days after exposure. [2] Symptoms often develop gradually, beginning with a sore throat and fever. [1] In severe cases, a grey or white patch develops in the throat, [2] [1] which can block the airway, and create a barking cough similar to what is observed in croup. [1] The neck may also swell, in part due to the enlargement of the facial lymph nodes. [2] Diphtheria can also involve the skin, eyes, or genitals, and can cause [2] [1] complications, including myocarditis (which in itself can result in an abnormal heart rate), inflammation of nerves (which can result in paralysis), kidney problems, and bleeding problems due to low levels of platelets. [2]
Diphtheria is usually spread between people by direct contact, through the air, or through contact with contaminated objects. [2] [5] Asymptomatic transmission and chronic infection are also possible. [2] Different strains of C. diphtheriae are the main cause in the variability of lethality, [2] as the lethality and symptoms themselves are caused by the exotoxin produced by the bacteria. [1] Diagnosis can often be made based on the appearance of the throat with confirmation by microbiological culture. [1] Previous infection may not protect against reinfection. [1]
A diphtheria vaccine is effective for prevention, and is available in a number of formulations. [2] Three or four doses, given along with tetanus vaccine and pertussis vaccine, are recommended during childhood. [2] Further doses of the diphtheria–tetanus vaccine are recommended every ten years. [2] Protection can be verified by measuring the antitoxin level in the blood. [2] Diphtheria can be prevented in those exposed, as well as treated with the antibiotics erythromycin or benzylpenicillin. [2] In severe cases a tracheotomy may be needed to open the airway. [1]
In 2015, 4,500 cases were officially reported worldwide, down from nearly 100,000 in 1980. [3] About a million cases a year are believed to have occurred before the 1980s. [1] Diphtheria currently occurs most often in sub-Saharan Africa, South Asia, and Indonesia. [1] [6] In 2015, it resulted in 2,100 deaths, down from 8,000 deaths in 1990. [4] [7] In areas where it is still common, children are most affected. [1] It is rare in the developed world due to widespread vaccination, but can re-emerge if vaccination rates decrease. [1] [8] In the United States, 57 cases were reported between 1980 and 2004. [2] Death occurs in 5–10% of those diagnosed. [2] The disease was first described in the 5th century BC by Hippocrates. [2] The bacterium was identified in 1882 by Edwin Klebs. [2]
The symptoms of diphtheria usually begin two to seven days after infection. They include fever of 38 °C (100.4 °F) or above; chills; fatigue; bluish skin coloration (cyanosis); sore throat; hoarseness; cough; headache; difficulty swallowing; painful swallowing; difficulty breathing; rapid breathing; foul-smelling and bloodstained nasal discharge; and lymphadenopathy. [9] [10] Within two to three days, diphtheria may destroy healthy tissues in the respiratory system. The dead tissue forms a thick, gray coating that can build up in the throat or nose. This thick gray coating is called a "pseudomembrane." It can cover tissues in the nose, tonsils, voice box, and throat, making it very hard to breathe and swallow. [11] Symptoms can also include cardiac arrhythmias, myocarditis, and cranial and peripheral nerve palsies. [12]
Laryngeal diphtheria can lead to a characteristic swollen neck and throat, or "bull neck." The swollen throat is often accompanied by a serious respiratory condition, characterized by a brassy or "barking" cough, stridor, hoarseness, and difficulty breathing; and historically referred to variously as "diphtheritic croup," [13] "true croup," [14] [15] or sometimes simply as "croup." [16] Diphtheritic croup is extremely rare in countries where diphtheria vaccination is customary. As a result, the term "croup" nowadays most often refers to an unrelated viral illness that produces similar but milder respiratory symptoms. [17]
Human-to-human transmission of diphtheria typically occurs through the air when an infected individual coughs or sneezes. Breathing in particles released from the infected individual leads to infection. [18] Contact with any lesions on the skin can also lead to transmission of diphtheria, but this is uncommon. [19] Indirect infections can occur, as well. If an infected individual touches a surface or object, the bacteria can be left behind and remain viable. Also, some evidence indicates diphtheria has the potential to be zoonotic, but this has yet to be confirmed. Corynebacterium ulcerans has been found in some animals, which would suggest zoonotic potential. [20]
Diphtheria toxin (DT) is produced only by C. diphtheriae infected with a certain type of bacteriophage. [21] [22] Toxinogenicity is determined by phage conversion (also called lysogenic conversion); i.e., the ability of the bacterium to make DT changes as a consequence of infection by a particular phage. DT is encoded by the tox gene. Strains of corynephage are either tox+ (e.g., corynephage β) or tox− (e.g., corynephage γ). The tox gene becomes integrated into the bacterial genome. [23] The chromosome of C. diphtheriae has two different but functionally equivalent bacterial attachment sites (attB) for integration of β prophage into the chromosome.
The diphtheria toxin precursor is a protein of molecular weight 60 kDa. Certain proteases, such as trypsin, selectively cleave DT to generate two peptide chains, amino-terminal fragment A (DT-A) and carboxyl-terminal fragment B (DT-B), which are held together by a disulfide bond. [23] DT-B is a recognition subunit that gains entry of DT into the host cell by binding to the EGF-like domain of heparin-binding EGF-like growth factor on the cell surface. This signals the cell to internalize the toxin within an endosome via receptor-mediated endocytosis. Inside the endosome, DT is split by a trypsin-like protease into DT-A and DT-B. The acidity of the endosome causes DT-B to create pores in the endosome membrane, thereby catalysing the release of DT-A into the cytoplasm. [23]
Fragment A inhibits the synthesis of new proteins in the affected cell by catalyzing ADP-ribosylation of elongation factor EF-2—a protein that is essential to the translation step of protein synthesis. This ADP-ribosylation involves the transfer of an ADP-ribose from NAD+ to a diphthamide (a modified histidine) residue within the EF-2 protein. Since EF-2 is needed for the moving of tRNA from the A-site to the P-site of the ribosome during protein translation, ADP-ribosylation of EF-2 prevents protein synthesis. [24]
ADP-ribosylation of EF-2 is reversed by giving high doses of nicotinamide (a form of vitamin B3), since this is one of the reaction's end products, and high amounts drive the reaction in the opposite direction. [25]
The current clinical case definition of diphtheria used by the United States' Centers for Disease Control and Prevention is based on both laboratory and clinical criteria.
Empirical treatment should generally be started in a patient in whom suspicion of diphtheria is high.
Vaccination against diphtheria is commonly done in infants, and delivered as a combination vaccine, such as a DPT vaccine (diphtheria, pertussis, tetanus). Pentavalent vaccines, which vaccinate against diphtheria and four other childhood diseases simultaneously, are frequently used in disease prevention programs in developing countries by organizations such as UNICEF. [26]
The disease may remain manageable, but in more severe cases, lymph nodes in the neck may swell, and breathing and swallowing are more difficult. People in this stage should seek immediate medical attention, as obstruction in the throat may require intubation or a tracheotomy. Abnormal cardiac rhythms can occur early in the course of the illness or weeks later, and can lead to heart failure. Diphtheria can also cause paralysis in the eye, neck, throat, or respiratory muscles. Patients with severe cases are put in a hospital intensive care unit, and given diphtheria antitoxin (consisting of antibodies isolated from the serum of horses that have been challenged with diphtheria toxin). [27] Since antitoxin does not neutralize toxin that is already bound to tissues, delaying its administration increases risk of death. Therefore, the decision to administer diphtheria antitoxin is based on clinical diagnosis, and should not await laboratory confirmation. [28]
Antibiotics have not been demonstrated to affect healing of local infection in diphtheria patients treated with antitoxin. Antibiotics are used in patients or carriers to eradicate C. diphtheriae, and prevent its transmission to others. The Centers for Disease Control and Prevention (CDC) recommends [29] either:
In cases that progress beyond a throat infection, diphtheria toxin spreads through the blood, and can lead to potentially life-threatening complications that affect other organs, such as the heart and kidneys. Damage to the heart caused by the toxin affects the heart's ability to pump blood, or the kidneys' ability to clear wastes. It can also cause nerve damage, eventually leading to paralysis. About 40–50% of those left untreated can die.[ citation needed ] [30]
Diphtheria is fatal in 5–10% of cases. In children under five years and adults over 40 years, the fatality rate may be as much as 20%. [28] In 2013, it resulted in 3,300 deaths, down from 8,000 deaths in 1990. [7] Better standards of living, mass immunization, improved diagnosis, prompt treatment, and more effective health care have led to a decrease in cases worldwide. [31]
In 1613, Spain experienced an epidemic of diphtheria, referred to as El Año de los Garrotillos (The Year of Strangulations). [31]
In 1705, the Mariana Islands experienced an epidemic of diphtheria and typhus simultaneously, reducing the population to about 5,000 people. [32]
In 1735, a diphtheria epidemic swept through New England. [33]
Before 1826, diphtheria was known by different names across the world. In England, it was known as "Boulogne sore throat," as the illness had spread from France. In 1826, Pierre Bretonneau gave the disease the name diphthérite (from Greek διφθέρα, diphthera 'leather'), describing the appearance of pseudomembrane in the throat. [34] [35]
In 1856, Victor Fourgeaud described an epidemic of diphtheria in California. [36]
In 1878, Princess Alice (Queen Victoria's second daughter) and her family became infected with diphtheria; Princess Alice and her four-year-old daughter, Princess Marie, both died. [37] [ self-published source ]
In 1883, Edwin Klebs identified the bacterium causing diphtheria, [38] and named it Klebs–Loeffler bacterium. The club shape of this bacterium helped Edwin to differentiate it from other bacteria. Over time, it has been called Microsporon diphtheriticum, Bacillus diphtheriae, and Mycobacterium diphtheriae. Current nomenclature is Corynebacterium diphtheriae. [39]
In 1884, German bacteriologist Friedrich Loeffler became the first person to cultivate C. diphtheriae. [40] He used Koch's postulates to prove association between C. diphtheriae and diphtheria. He also showed that the bacillus produces an exotoxin.[ citation needed ]
In 1885, Joseph P. O'Dwyer introduced the O'Dwyer tube for laryngeal intubation in patients with an obstructed larynx. It soon replaced tracheostomy as the emergency diphtheric intubation method. [41]
In 1888, Emile Roux and Alexandre Yersin showed that a substance produced by C. diphtheriae caused symptoms of diphtheria in animals. [42] [43]
In 1890, Shibasaburō Kitasato and Emil von Behring immunized guinea pigs with heat-treated diphtheria toxin. [44] They also immunized goats and horses in the same way, and showed that an "antitoxin" made from serum of immunized animals could cure the disease in non-immunized animals. Behring used this antitoxin (now known to consist of antibodies that neutralize the toxin produced by C. diphtheriae) for human trials in 1891, but they were unsuccessful. Successful treatment of human patients with horse-derived antitoxin began in 1894, after production and quantification of antitoxin had been optimized. [45] [27] In 1901, Von Behring won the first Nobel Prize in medicine for his work on diphtheria. [46]
In 1895, H. K. Mulford Company of Philadelphia started production and testing of diphtheria antitoxin in the United States. [47] Park and Biggs described the method for producing serum from horses for use in diphtheria treatment.[ citation needed ]
In 1897, Paul Ehrlich developed a standardized unit of measure for diphtheria antitoxin. This was the first ever standardization of a biological product, and played an important role in future developmental work on sera and vaccines. [48]
In 1901, 10 of 11 inoculated St. Louis children died from contaminated diphtheria antitoxin. The horse from which the antitoxin was derived died of tetanus. This incident, coupled with a tetanus outbreak in Camden, New Jersey, [49] played an important part in initiating federal regulation of biologic products. [50]
On 7 January 1904, Ruth Cleveland died of diphtheria at the age of 12 years in Princeton, New Jersey. Ruth was the eldest daughter of former President Grover Cleveland and the former First Lady, Frances Folsom.[ citation needed ]
In 1905, Franklin Royer, from Philadelphia's Municipal Hospital, published a paper urging timely treatment for diphtheria and adequate doses of antitoxin. [51] In 1906, Clemens Pirquet and Béla Schick described serum sickness in children receiving large quantities of horse-derived antitoxin. [52]
Between 1910 and 1911, Béla Schick developed the Schick test to detect pre-existing immunity to diphtheria in an exposed person. Only those who had not been exposed to diphtheria were vaccinated. A massive, five-year campaign was coordinated by Dr. Schick. As a part of the campaign, 85 million pieces of literature were distributed by the Metropolitan Life Insurance Company, with an appeal to parents to "Save your child from diphtheria." A vaccine was developed in the next decade, and deaths began declining significantly in 1924. [53]
In 1919, in Dallas, Texas, 10 children were killed and 60 others made seriously ill by toxic antitoxin which had passed the tests of the New York State Health Department. The manufacturer of the antitoxin, the Mulford Company of Philadelphia, paid damages in every case. [54]
During the 1920s, an annual estimate of 100,000 to 200,000 diphtheria cases and 13,000 to 15,000 deaths occurred in the United States. [28] Children represented a large majority of these cases and fatalities. One of the most infamous outbreaks of diphtheria occurred in 1925, in Nome, Alaska; the "Great Race of Mercy" to deliver diphtheria antitoxin is now celebrated by the Iditarod Trail Sled Dog Race. [55]
In 1926, Alexander Thomas Glenny increased the effectiveness of diphtheria toxoid (a modified version of the toxin used for vaccination) by treating it with aluminum salts. [56] Vaccination with toxoid was not widely used until the early 1930s. [57] In 1939, Dr. Nora Wattie, who was the Principal Medical Officer (Maternity and Child Welfare) of Glasgow between 1934– 1964, [58] introduced immunisation clinics across Glasgow, and promoted mother and child health education, resulting in virtual eradication of the infection in the city. [59]
Widespread vaccination pushed cases in the United States down from 4.4 per 100,000 inhabitants in 1932 to 2.0 in 1937. In Nazi Germany, where authorities preferred treatment and isolation over vaccination (until about 1939–1941), cases rose over the same period from 6.1 to 9.6 per 100,000 inhabitants. [60]
Between June 1942 and February 1943, 714 cases of diphtheria were recorded at Sham Shui Po Barracks, resulting in 112 deaths because the Imperial Japanese Army did not release supplies of anti-diphtheria serum. [61]
In 1943, diphtheria outbreaks accompanied war and disruption in Europe. The 1 million cases in Europe resulted in 50,000 deaths.[ citation needed ]
During 1948 in Kyoto, 68 of 606 children died after diphtheria immunization due to improper manufacture of aluminum phosphate toxoid. [62]
In 1974, the World Health Organization included DPT vaccine in their Expanded Programme on Immunization for developing countries. [63] [64]
In 1975, an outbreak of cutaneous diphtheria in Seattle, Washington, was reported. [65]
After the breakup of the former Soviet Union in 1991, vaccination rates in its constituent countries fell so low that an explosion of diphtheria cases occurred. In 1991, 2,000 cases of diphtheria occurred in the USSR. Between 1991 and 1998, as many as 200,000 cases were reported in the Commonwealth of Independent States, and resulted in 5,000 deaths. [31] In 1994, the Russian Federation had 39,703 diphtheria cases. By contrast, in 1990, only 1,211 cases were reported. [66]
In early May 2010, a case of diphtheria was diagnosed in Port-au-Prince, Haiti, after the devastating 2010 Haiti earthquake. The 15-year-old male patient died while workers searched for antitoxin. [67]
In 2013, three children died of diphtheria in Hyderabad, India. [68]
In early June 2015, a case of diphtheria was diagnosed at Vall d'Hebron University Hospital in Barcelona, Spain. The six-year-old child who died of the illness had not been previously vaccinated due to parental opposition to vaccination. [69] It was the first case of diphtheria in the country since 1986, as reported by the Spanish daily newspaper El Mundo, [70] or from 1998, as reported by the WHO. [71]
In March 2016, a three-year-old girl died of diphtheria in the University Hospital of Antwerp, Belgium. [72]
In June 2016, a three-year-old, five-year-old, and seven-year-old girl died of diphtheria in Kedah, Malacca, and Sabah, Malaysia. [73]
In January 2017, more than 300 cases were recorded in Venezuela. [74] [75]
In 2017, outbreaks occurred in a Rohingya refugee camp in Bangladesh, and amongst children unvaccinated due to the Yemeni Civil War. [76]
In November and December 2017, an outbreak of diphtheria occurred in Indonesia, with more than 600 cases found and 38 fatalities. [77]
In November 2019, two cases of diphtheria occurred in the Lothian area of Scotland. [78] Additionally, in November 2019, an unvaccinated 8-year-old boy died of diphtheria in Athens, Greece. [79]
In July 2022, two cases of diphtheria occurred in northern New South Wales, Australia. [80]
In October 2022, there was an outbreak of diphtheria at the former Manston airfield, a former Ministry of Defence (MoD) site in Kent, England, which had been converted to an asylum seeker processing centre. The capacity of the processing centre was 1,000 people, although about 3,000 were living at the site, with some accommodated in tents. The Home Office, the government department responsible for asylum seekers, refused to confirm the number of cases. [81]
In December 2023 there was an outbreak at a school in Luton, in the United Kingdom. UK Health Security Agency (UKHSA) issued a statement saying specialists have been providing public health support following confirmation of the diphtheria case at a primary school in Luton. The agency said it is working closely with local and national partners "to ensure all necessary public health measures are implemented" following the discovery of the new case. The statement added: "We have conducted a risk assessment and close contacts of the case have been identified and where appropriate, vaccination and advice will be given to prevent the spread of the infection." [82]
Tetanus, also known as lockjaw, is a bacterial infection caused by Clostridium tetani and characterized by muscle spasms. In the most common type, the spasms begin in the jaw and then progress to the rest of the body. Each spasm usually lasts for a few minutes. Spasms occur frequently for three to four weeks. Some spasms may be severe enough to fracture bones. Other symptoms of tetanus may include fever, sweating, headache, trouble swallowing, high blood pressure, and a fast heart rate. The onset of symptoms is typically 3 to 21 days following infection. Recovery may take months; about 10% of cases prove to be fatal.
In biology, immunity is the state of being insusceptible or resistant to a noxious agent or process, especially a pathogen or infectious disease. Immunity may occur naturally or be produced by prior exposure or immunization.
Croup, also known as croupy cough, is a type of respiratory infection that is usually caused by a virus. The infection leads to swelling inside the trachea, which interferes with normal breathing and produces the classic symptoms of "barking/brassy" cough, inspiratory stridor and a hoarse voice. Fever and runny nose may also be present. These symptoms may be mild, moderate, or severe. Often it starts or is worse at night and normally lasts one to two days.
An exotoxin is a toxin secreted by bacteria. An exotoxin can cause damage to the host by destroying cells or disrupting normal cellular metabolism. They are highly potent and can cause major damage to the host. Exotoxins may be secreted, or, similar to endotoxins, may be released during lysis of the cell. Gram negative pathogens may secrete outer membrane vesicles containing lipopolysaccharide endotoxin and some virulence proteins in the bounding membrane along with some other toxins as intra-vesicular contents, thus adding a previously unforeseen dimension to the well-known eukaryote process of membrane vesicle trafficking, which is quite active at the host–pathogen interface.
An antitoxin is an antibody with the ability to neutralize a specific toxin. Antitoxins are produced by certain animals, plants, and bacteria in response to toxin exposure. Although they are most effective in neutralizing toxins, they can also kill bacteria and other microorganisms. Antitoxins are made within organisms, and can be injected into other organisms, including humans, to treat an infectious disease. This procedure involves injecting an animal with a safe amount of a particular toxin. The animal's body then makes the antitoxin needed to neutralize the toxin. Later, blood is withdrawn from the animal. When the antitoxin is obtained from the blood, it is purified and injected into a human or other animal, inducing temporary passive immunity. To prevent serum sickness, it is often best to use an antitoxin obtained from the same species.
The DPT vaccine or DTP vaccine is a class of combination vaccines to protect against three infectious diseases in humans: diphtheria, pertussis, and tetanus (lockjaw). The vaccine components include diphtheria and tetanus toxoids, and either killed whole cells of the bacterium that causes pertussis or pertussis antigens. The term toxoid refers to vaccines which use an inactivated toxin produced by the pathogen which they are targeted against to generate an immune response. In this way, the toxoid vaccine generates an immune response which is targeted against the toxin which is produced by the pathogen and causes disease, rather than a vaccine which is targeted against the pathogen itself. The whole cells or antigens will be depicted as either "DTwP" or "DTaP", where the lower-case "w" indicates whole-cell inactivated pertussis and the lower-case "a" stands for "acellular". In comparison to alternative vaccine types, such as live attenuated vaccines, the DTP vaccine does not contain any live pathogen, but rather uses inactivated toxoid to generate an immune response; therefore, there is not a risk of use in populations that are immune compromised since there is not any known risk of causing the disease itself. As a result, the DTP vaccine is considered a safe vaccine to use in anyone and it generates a much more targeted immune response specific for the pathogen of interest.
Corynebacterium diphtheriae is a Gram-positive pathogenic bacterium that causes diphtheria. It is also known as the Klebs–Löffler bacillus because it was discovered in 1884 by German bacteriologists Edwin Klebs (1834–1912) and Friedrich Löffler (1852–1915). These bacteria are usually harmless, unless they are infected by a bacteriophage carrying a gene which gives rise to a toxin. This toxin causes the disease. Diphtheria is caused by the adhesion and infiltration of the bacteria into the mucosal layers of the body, primarily affecting the respiratory tract and causing the subsequent release of an exotoxin. The toxin has a localized effect on skin lesions, as well as a metastatic, proteolytic effects on other organ systems in severe infections. Originally a major cause of childhood mortality, diphtheria has been almost entirely eradicated due to the vigorous administration of the diphtheria vaccination in the 1910s.
A toxoid is an inactivated toxin whose toxicity has been suppressed either by chemical (formalin) or heat treatment, while other properties, typically immunogenicity, are maintained. Toxins are secreted by bacteria, whereas toxoids are altered form of toxins; toxoids are not secreted by bacteria. Thus, when used during vaccination, an immune response is mounted and immunological memory is formed against the molecular markers of the toxoid without resulting in toxin-induced illness. Such a preparation is also known as an anatoxin. There are toxoids for prevention of diphtheria, tetanus and botulism.
The schedule for childhood immunizations in the United States is published by the Centers for Disease Control and Prevention (CDC). The vaccination schedule is broken down by age: birth to six years of age, seven to eighteen, and adults nineteen and older. Childhood immunizations are key in preventing diseases with epidemic potential.
Meningococcal disease describes infections caused by the bacterium Neisseria meningitidis. It has a high mortality rate if untreated but is vaccine-preventable. While best known as a cause of meningitis, it can also result in sepsis, which is an even more damaging and dangerous condition. Meningitis and meningococcemia are major causes of illness, death, and disability in both developed and under-developed countries.
Diphtheria antitoxin (DAT) is a medication made up of antibodies used in the treatment of diphtheria. It is no longer recommended for prevention of diphtheria. It is administered through injection into a vein or muscle.
In immunology, passive immunity is the transfer of active humoral immunity of ready-made antibodies. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta, and it can also be induced artificially, when high levels of antibodies specific to a pathogen or toxin are transferred to non-immune persons through blood products that contain antibodies, such as in immunoglobulin therapy or antiserum therapy. Passive immunization is used when there is a high risk of infection and insufficient time for the body to develop its own immune response, or to reduce the symptoms of ongoing or immunosuppressive diseases. Passive immunization can be provided when people cannot synthesize antibodies, and when they have been exposed to a disease that they do not have immunity against.
William Hallock Park was an American bacteriologist and laboratory director at the New York City Board of Health, Division of Pathology, Bacteriology, and Disinfection from 1893 to 1936.
Diphtheria vaccine is a toxoid vaccine against diphtheria, an illness caused by Corynebacterium diphtheriae. Its use has resulted in a more than 90% decrease in number of cases globally between 1980 and 2000. The first dose is recommended at six weeks of age with two additional doses four weeks apart, after which it is about 95% effective during childhood. Three further doses are recommended during childhood. It is unclear if further doses later in life are needed.
Pertussis vaccine is a vaccine that protects against whooping cough (pertussis). There are two main types: whole-cell vaccines and acellular vaccines. The whole-cell vaccine is about 78% effective while the acellular vaccine is 71–85% effective. The effectiveness of the vaccines appears to decrease by between 2 and 10% per year after vaccination with a more rapid decrease with the acellular vaccines. The vaccine is only available in combination with tetanus and diphtheria vaccines. Pertussis vaccine is estimated to have saved over 500,000 lives in 2002.
Microbial toxins are toxins produced by micro-organisms, including bacteria, fungi, protozoa, dinoflagellates, and viruses. Many microbial toxins promote infection and disease by directly damaging host tissues and by disabling the immune system. Endotoxins most commonly refer to the lipopolysaccharide (LPS) or lipooligosaccharide (LOS) that are in the outer plasma membrane of Gram-negative bacteria. The botulinum toxin, which is primarily produced by Clostridium botulinum and less frequently by other Clostridium species, is the most toxic substance known in the world. However, microbial toxins also have important uses in medical science and research. Currently, new methods of detecting bacterial toxins are being developed to better isolate and understand these toxins. Potential applications of toxin research include combating microbial virulence, the development of novel anticancer drugs and other medicines, and the use of toxins as tools in neurobiology and cellular biology.
Elek's test or the Elek plate test is an in vitro test of virulence performed on specimens of Corynebacterium diphtheriae, the bacteria that causes diphtheria. It is used to test for toxigenicity of C. diphtheriae strains.
Tetanus vaccine, also known as tetanus toxoid (TT), is a toxoid vaccine used to prevent tetanus. During childhood, five doses are recommended, with a sixth given during adolescence.
Corynebacterium ulcerans is a rod-shaped, aerobic, and Gram-positive bacterium. Most Corynebacterium species are harmless, but some cause serious illness in humans, especially in immunocompromised humans. C. ulcerans has been known to cause diphtheria and diphtheria-like infections in patients. Previously thought to simply be contaminants recovered from diphtheria patients, “coryneform” or “diphtheroids” are now believed to be the cause of such infections.
DTaP-IPV-HepB vaccine is a combination vaccine whose generic name is diphtheria and tetanus toxoids and acellular pertussis adsorbed, hepatitis B (recombinant) and inactivated polio vaccine or DTaP-IPV-Hep B. It protects against the infectious diseases diphtheria, tetanus, pertussis, poliomyelitis, and hepatitis B.