Bacteria[ edit ] The Gram-negative bacterium that causes typhoid fever is Salmonella enterica subsp. Typhi are ST1 and ST2, which are currently widespread globally. This scheme re-classified the nomemclature of H58 to genotype 4. 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 the Widal test and cultures of the blood and stool. In this test, the serum is mixed with a dead bacterial suspension of salmonella having specific antigens on it.
|Published (Last):||4 September 2013|
|PDF File Size:||16.52 Mb|
|ePub File Size:||2.36 Mb|
|Price:||Free* [*Free Regsitration Required]|
Bacteria[ edit ] The Gram-negative bacterium that causes typhoid fever is Salmonella enterica subsp. Typhi are ST1 and ST2, which are currently widespread globally. This scheme re-classified the nomemclature of H58 to genotype 4. 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 the Widal test and cultures of the blood and stool.
In this test, the serum is mixed with a dead bacterial suspension of salmonella having specific antigens on it. If clumping does not occur then the test is negative. The Widal test is time-consuming and prone to significant false positive results. The test may also be falsely negative in the early course of illness. However, unlike the Typhidot test, the Widal test quantifies the specimen with titres.
This test is carried out on a cellulose nitrate membrane where a specific S. It separately identifies IgM and IgG antibodies. IgM shows recent infection whereas IgG signifies remote infection. The sample pad of this kit contains colloidal gold-anti-human IgG or gold-anti-human IgM. If the sample contains IgG and IgM antibodies against those antigens then they will react and get turned into red color. This complex will continue to move forward and the IgG and IgM antibodies will get attached to the first test line where IgG and IgM antigens are present giving a pink-purplish colored band.
This complex will continue to move further and reach the control line which consists of rabbit anti-mouse antibody which bends the mouse anti-human IgG or IgM antibodies. The main purpose of the control line is to indicate a proper migration and reagent color. The typhidot test becomes positive within 2—3 days of infection. Two colored bands indicate a positive test. Single-band of control line indicates a negative test.
Single-band of first fixed line or no bands at all indicates invalid tests. The most important limitation of this test is that it is not quantitative and the result is only positive or negative. During the test, if antibodies are present in the serum then they will get attached to the brown magnetic particles and settle down at the base and the blue indicator particles remain up in the solution giving a blue color that indicates positivity of the test.
If the serum does not have an antibody in it then the blue particle gets attached to the brown particles and settled down at the bottom giving no color to the solution which means the test is negative and they do not have typhoid.
It can only spread in environments where human feces are able to come into contact with food or drinking water. Careful food preparation and washing of hands are crucial to prevent typhoid. Industrialization, and in particular, the invention of the automobile, contributed greatly to the elimination of typhoid fever, as it eliminated the public-health hazards associated with having horse manure in public streets, which led to large number of flies,  which are known as vectors of many pathogens, including Salmonella spp.
Both are efficacious and recommended for travellers to areas where typhoid is endemic. Boosters are recommended every five years for the oral vaccine and every two years for the injectable form.
Vaccinations have proven to be a great way at controlling outbreaks in high incidence areas. Just as important, it is also very cost-effective.
Because the price is low, poverty-stricken communities are more willing to take advantage of the vaccinations. The ViPS vaccine is given via injection, while the Ty21a is taken through capsules. The two different vaccines have been proven as a safe and effective treatment for epidemic disease control in multiple regions.
Antibiotics, such as ampicillin , chloramphenicol, trimethoprim-sulfamethoxazole , amoxicillin , and ciprofloxacin, have been commonly used to treat typhoid fever. The highest case fatality rates are reported in children under 4 years. Small-bowel resection is indicated for patients with multiple perforations. If antibiotic treatment fails to eradicate the hepatobiliary carriage, the gallbladder should be resected.
Cholecystectomy is sometimes successful, especially in patients with gallstones , but is not always successful in eradicating the carrier state because of persisting hepatic infection. Many centres are shifting from using ciprofloxacin as the first line for treating suspected typhoid originating in South America, India, Pakistan, Bangladesh, Thailand, or Vietnam.
For these people, the recommended first-line treatment is ceftriaxone. Also, azithromycin has been suggested to be better at treating resistant typhoid in populations than both fluoroquinolone drugs and ceftriaxone.
What are the causes and risk factors? Typhoid is caused by bacteria called Salmonella typhi S. Its main method of transmission is the oral-fecal route, generally spreading in contaminated water or food. It can also be passed through direct contact with an infected person. In addition, there are a small number of people who recover but still carry S. Some regions have a higher incidence of typhoid. Worldwide, typhoid fever affects more than 26 million people per year.
She migrated to the United States in or In , she moved to Manhattan , where members of the family for whom she worked developed fevers and diarrhea , and the laundress died. Mallon then went to work for a lawyer and left after seven of the eight people in that household became ill. When the Warrens rented a house in Oyster Bay for the summer of , Mallon went along too. From August 27 to September 3, six of the 11 people in the family came down with typhoid fever. The disease at that time was "unusual" in Oyster Bay, according to three medical doctors who practiced there.
La fièvre typhoïde, qu'est-ce que c'est ?