La fièvre typhoïde (du grec tuphos, torpeur) ou typhus abdominal est une maladie infectieuse décrite en 1818 par Pierre Bretonneau, causée par une bactérie de la famille Entérobactérie, du genre des salmonelles, et dont les espèces responsables sont: Salmonella enterica - typhi ou paratyphi A, B, C - . Salmonella enterica typhi est encore appelée bacille d'Eberth.
La contamination se fait par l'ingestion de boissons ou aliments souillés par les selles d'un homme infecté, malade, ou porteur sain. La typhoïde a rapidement régressé en France et en Europe suite à la javellisation de l'eau de boisson généralisée- du moins en ville- à partir de 1910 2.
La maladie est quasiment absente des pays développés, mais reste fréquente dans les autres. Sa prévalence est importante en Asie du Sud-Est, en Asie centrale et en Afrique du Sud. Le germe le plus souvent responsable reste Salmonella typhi, près de dix fois plus fréquemment retrouvé que les Salmonella paratyphi.
Quarante-huit heures après la contamination, survient un épisode de diarrhée transitoire. Cet épisode dure une dizaine de jours (8 à 15), et correspond à la période d'incubation, pendant laquelle il y a multiplication des salmonelles dans les ganglions mésentériques; il précède la phase de dissémination du germe dans le sang (septicémie).
Au début de la phase septicémique, on observe des troubles mineurs:
Le malade est prostré, la prostration pouvant aller jusqu'à la torpeur, le délire, et à des signes digestifs intenses (diarrhées). C’est la destruction des salmonelles, qui, libérant une substance toxique, l'endotoxine, provoque des ulcérations responsables d'hémorragies et de perforations digestives. Cette phase est responsable des complications, qui peuvent entraîner le décès dans 30 % des cas en l'absence de traitement.
Le germe était initialement sensible au chloramphénicol, mais de nombreuses résistances apparurent dans les années 1970, et ce traitement, aux nombreux effets secondaires, a été progressivement abandonné. De même, des résistances à d'autres antibiotiques (co-trimoxazole et amoxicilline) sont apparues dans les années 1980.
Après avoir hospitalisé et isolé le malade, le traitement fait appel actuellement aux fluoroquinolones de deuxième génération ou à la ceftriaxone. La réhydratation, souvent par voie intraveineuse, est impérative pour compenser les pertes liquidiennes secondaires à la diarrhée. Un traitement contre la fièvre (antipyrétique) peut parfois être nécessaire.
La prévention passe par l'amélioration des conditions d'hygiène dans les pays d'endémie et par la vaccination. Les visiteurs doivent se méfier de l'eau locale et de la nourriture crue.
En 1888, André Chantemesse (créant le sérum de Chantemesse) et Widal démontrent la possibilité d'un vaccin contre la typhoïde3, qui sera développé par Sir Almroth Wright en 1896 (Pfeiffer lui en disputera l'antériorité 4). Le vaccin contre la typhoïde a servi dans le passé5, et encore récemment6, comme agent de la pyretothérapie / pyrothérapie.
Typhoid fever, also known as Salmonella Typhi or commonly just typhoid, is a common worldwide illness, transmitted by the ingestion of food or water contaminated with the feces of an infected person. The bacteria then perforate through the intestinal wall and are phagocytosed by macrophages. The organism is a Gram-negative short bacillus that is motile due to its peritrichousflagella. The bacterium grows best at 37 °C/99 °F – human body temperature.
This fever received various names, such as gastric fever, the bends, abdominal typhus, infantile remittent fever, slow fever, nervous fever, pythogenic fever, etc. The name of " typhoid " was given by Louis in 1829, as a derivative from typhus.
The impact of this disease falls sharply with the application of modern sanitation techniques.
Typhoid fever is characterized by a slowly progressive fever as high as 40 °C (104 °F), profuse sweating, gastroenteritis, and nonbloody diarrhea. Less commonly, a rash of flat, rose-colored spots may appear.
Classically, the course of untreated typhoid fever is divided into four individual stages, each lasting approximately one week. In the first week, there is a slowly rising temperature with relative bradycardia, malaise, headache and cough. A bloody nose (epistaxis) is seen in a quarter of cases and abdominal pain is also possible. There is leukopenia, a decrease in the number of circulating white blood cells, with eosinopenia and relative lymphocytosis, a positive diazo reaction and blood cultures are positive for Salmonella typhi or paratyphi. The classic Widal test is negative in the first week.
In the second week of the infection, the patient lies prostrate with high fever in plateau around 40 °C (104 °F) and bradycardia (sphygmothermic dissociation), classically with a dicrotic pulse wave. Delirium is frequent, frequently calm, but sometimes agitated. This delirium gives to typhoid the nickname of "nervous fever". Rose spots appear on the lower chest and abdomen in around a third of patients. There are rhonchi in lung bases. The abdomen is distended and painful in the right lower quadrant where borborygmi can be heard. Diarrhea can occur in this stage : six to eight stools in a day, green with a characteristic smell, comparable to pea soup. However, constipation is also frequent. The spleen and liver are enlarged (hepatosplenomegaly) and tender, and there is elevation of liver transaminases. The Widal reaction is strongly positive with antiO and antiH antibodies. Blood cultures are sometimes still positive at this stage. (The major symptom of this fever is the fever usually rises in the afternoon up to the first and second week.)
In the third week of typhoid fever, a number of complications can occur :
The fever is still very high and oscillates very little over 24 hours. Dehydration ensues and the patient is delirious (typhoid state). By the end of third week the fever has started reducing (defervescence). This carries on into the fourth and final week.
Diagnosis is made by any blood, bone marrow or stool cultures and with the Widal test (demonstration of salmonella antibodies against antigens O-somatic and H-flagellar). In epidemics and less wealthy countries, after excluding malaria, dysentery or pneumonia, a therapeutic trial time with chloramphenicol is generally undertaken while awaiting the results of Widal test and cultures of the blood and stool.
The term "enteric fever" is a collective term that refers to typhoid and paratyphoid.
Where resistance is uncommon, the treatment of choice is a fluoroquinolone such as ciprofloxacin otherwise, a third-generation cephalosporin such as ceftriaxone or cefotaxime is the first choice. Cefixime is a suitable oral alternative.
Typhoid fever in most cases is not fatal. Antibiotics, such as ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, Amoxicillin and ciprofloxacin, have been commonly used to treat typhoid fever in developed countries. Prompt treatment of the disease with antibiotics reduces the case-fatality rate to approximately 1%.
When untreated, typhoid fever persists for three weeks to a month. Death occurs in between 10% and 30 % of untreated cases. In some communities, however, case-fatality rates may reach as high as 47 %.
Resistance to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole and streptomycin is now common, and these agents have not been used as first line treatment now for almost 20 years. Typhoid that is resistant to these agents is known as multidrug-resistant typhoid (MDR typhoid).
Ciprofloxacin resistance is an increasing problem, especially in the Indian subcontinent and Southeast Asia. Many centres are therefore moving away from using ciprofloxacin as first line for treating suspected typhoid originating in South America, India, Pakistan, Bangladesh, Thailand or Vietnam. For these patients, the recommended first line treatment is ceftriaxone. It has also been suggested Azithromycin is better at treating typhoid in resistant populations than both fluoroquinolone drugs and ceftriaxone. Azithromycin significantly reduces relapse rates compared with ceftriaxone.
There is a separate problem with laboratory testing for reduced susceptibility to ciprofloxacin: current recommendations are that isolates should be tested simultaneously against ciprofloxacin (CIP) and against nalidixic acid (NAL), and that isolates that are sensitive to both CIP and NAL should be reported as "sensitive to ciprofloxacin", but that isolates testing sensitive to CIP but not to NAL should be reported as "reduced sensitivity to ciprofloxacin". However, an analysis of 271 isolates showed that around 18% of isolates with a reduced susceptibility to ciprofloxacin (MIC 0.125–1.0 mg/l) would not be picked up by this method. It is not certain how this problem can be solved, because most laboratories around the world (including the West) are dependent on disc testing and cannot test for MICs.
Sanitation and hygiene are the critical measures that can be taken to prevent typhoid. Typhoid does not affect animals and therefore transmission is only from human to human. Typhoid can only spread in environments where human feces or urine are able to come into contact with food or drinking water. Careful food preparation and washing of hands are crucial to preventing typhoid.
A vaccine against typhoid fever was developed during World War II by Ralph Walter Graystone Wyckoff. There are two vaccines currently recommended by the World Health Organization for the prevention of typhoid:these are the live, oral Ty21a vaccine (sold as Vivotif Berna) and the injectable Typhoid polysaccharide vaccine (sold as Typhim Vi by Sanofi Pasteur and Typherix by GlaxoSmithKline). Both are between 50% to 80% protective and are recommended for travelers to areas where typhoid is endemic. Boosters are recommended every 5 years for the oral vaccine and every 2 years for the injectable form. There exists an older killed whole-cell vaccine that is still used in countries where the newer preparations are not available, but this vaccine is no longer recommended for use, because it has a higher rate of side effects (mainly pain and inflammation at the site of the injection).
Flying insects feeding on feces may occasionally transfer the bacteria through poor hygiene habits and public sanitation conditions. Public education campaigns encouraging people to wash their hands after defecating and before handling food are an important component in controlling spread of the disease. According to statistics from the United States Center for Disease Control, the chlorination of drinking water has led to dramatic decreases in the transmission of typhoid fever in the U.S.
A person may become an asymptomatic carrier of typhoid fever, suffering no symptoms, but capable of infecting others. According to the Centers for Disease Control approximately 5% of people who contract typhoid continue to carry the disease after they recover. The most famous asymptomatic carrier was Mary Mallon (commonly known as "Typhoid Mary"), a young cook who was responsible for infecting at least 53 people with typhoid, three of whom died from the disease. Mallon was the first apparently perfectly healthy person known to be responsible for an "epidemic".
Many carriers of typhoid were locked into an isolation ward never to be released in order to prevent further typhoid cases. These people often deteriorated mentally, driven mad by the conditions they lived in.
With an estimated 16–33 million cases of annually resulting in 216,000 deaths in endemic areas, the World Health Organization identifies typhoid as a serious public health problem. Its incidence is highest in children and young adults between 5 and 19 years old.
It is thought that cystic fibrosis may have risen to its present levels (1 in 1600 in UK) due to the heterozygous advantage that it confers against typhoid fever. The CFTR protein is present in both the lungs and the intestinal epithelium, and the mutant cystic fibrosis form of the CFTR protein prevents entry of the typhoid bacterium into the body through the intestinal epithelium.
Around 430–424 B.C.E., a devastating plague, which some believe to have been typhoid fever, killed one third of the population of Athens, including their leader Pericles. The balance of power shifted from Athens toSparta, ending the Golden Age of Pericles that had marked Athenian dominance in the ancient world. Ancient historian Thucydides also contracted the disease, but he survived to write about the plague. His writings are the primary source on this outbreak. The cause of the plague has long been disputed, with modern academics and medical scientists considering epidemic typhus the most likely cause. However, a 2006 study detectedDNA sequences similar to those of the bacterium responsible for typhoid fever. Other scientists have disputed the findings, citing serious methodologic flaws in the dental pulp-derived DNA study. The disease is most commonly transmitted through poor hygiene habits and public sanitation conditions; during the period in question, the whole population of Attica was besieged within the Long Walls and lived in tents.
In the late 19th century, typhoid fever mortality rate in Chicago averaged 65 per 100,000 people a year. The worst year was 1891, when the typhoid death rate was 174 per 100,000 people. The most notorious carrier of typhoid fever—but by no means the most destructive—was Mary Mallon, also known as Typhoid Mary. In 1907, she became the first American carrier to be identified and traced. She was a cook in New York. She is closely associated with fifty-three cases and three deaths. Public health authorities told Mary to give up working as a cook or have her gall bladder removed. Mary quit her job but returned later under a false name. She was detained and quarantined after another typhoid outbreak. She died of pneumonia after 26 years in quarantine.
In 1897, Almroth Edward Wright developed an effective vaccine. In 1909, Frederick F. Russell, a U.S. Army physician, developed an American typhoid vaccine and two years later his vaccination program became the first in which an entire army was immunized. It eliminated typhoid as a significant cause of morbidity and mortality in the U.S. military.
Most developed countries saw declining rates of typhoid fever throughout the first half of the 20th century due to vaccinations and advances in public sanitation and hygiene. Antibiotics were introduced in clinical practice in 1942, greatly reducing mortality. Today, incidence of typhoid fever in developed countries is around 5 cases per 1,000,000 people per year.
Typhoid fever was also known as suette milliaire in nineteenth-century France.
Famous people who have had the disease include:
Died in 9 of January , 1934 by Typhoid fever.
The Kauffman and White classification scheme is a classification system that permits serological varieties of the genus Salmonella to be differentiated from each other. This scheme differentiates isolates by determining which surface antigens are produced by the bacterium. First, the "O" antigen type is determined. "O" antigens are the polysaccharides associated with the lipopolysaccharide of the bacterial outer membrane. Having found the "O" antigen group, the "H" antigen is determined. The "H" antigens are proteins associated with the bacterial flagella (singular; flagellum). Salmonellas exist in two phases; a motile phase and a non-motile phase. These are also referred to as the specific and non-specific phases. Different "H" antigens are produced depending on the phase in which the salmonella is found. Non-motile isolates may be "switched" to the motile phase using a Cragie tube - bacteria are inoculated down the center of a hollow tube in a semi-solid nutrient agar. Those bacteria that become motile can then swim out of the bottom of the tube and are recovered from the agar outside of the tube. Pathogenic strains of Salmonella typhi carry an additional antigen, "Vi", so-called because of the enhanced virulence of strains that produce this antigen, which is associated with a bacterial capsule.
The cost of maintaining a full set of antisera precludes all but reference laboratories from performing a complete serological identification of salmonella isolates. Most laboratories stock only a limited range of antisera, and the choice of stock sera is largely determined by the nature of the specimens to be processed.
A common set of working antisera is shown below:
Laboratories that are likely to investigate typhoid also carry antiserum raised against the Vi antigen.
A set of "Rapid Diagnostic Sera" is also held and is used for determination of common specific H-antigens except i-H. After obtaining a positive agglutination with the polyvalent-H specific and non-specific antiserum, the three RDS antisera are used to identify the H antigen present. Depending on the pattern of positive and negative reactions with the RDS antisera, the specific H antigen may be identified:
E = polyvalent for eh, enx, etc.