The chronic carrier state occurs more frequently with advanced age, and among females than males. (6)Īpproximately 2% to 4% of acute typhoid fever cases develop into a chronic carrier state. (4) Domestic surveillance could underestimate the risk of typhoid fever in travelers since the disease is unlikely to be reported for persons who received diagnosis and treatment overseas. Of these 414 cases, 1 (0.2%) case occurred in an infant under one year of age 77 (18.6%) cases occurred in persons one to nine years of age 81 (19.6%) cases occurred in persons 10 to 19 years of age 251 (60.6%) cases occurred in individuals ≥20 years of age the age was not available for 4 (1%) cases. In 1992, 414 cases of typhoid fever were reported to the CDC. During the periods of 1975 to 19 to 1984, respectively, 62% and 70% of the cases of typhoid fever reported to the CDC were acquired during foreign travel this compares to 33% of cases during 1967-1972. Most cases of typhoid fever in the US are thought to be acquired during foreign travel. Typhoid fever is still endemic in many countries of the world where it is predominantly a disease of school-age children and may be a major public health problem. (4) Infection of the gallbladder can lead to the chronic carrier state. (1) (2) (3) During the period of 1983 to 1991 in the US, the case fatality rate reported to the Centers for Disease Control and Prevention (CDC) was 0.2% (9/4010). The case fatality rate was reported to be approximately 10% to 20% in the pre-antibiotic era. The course is typically more severe without appropriate antimicrobial therapy. Among the less common but most severe complications are intestinal perforation and hemorrhage, and death. Constipation is common in older children and adults, while diarrhea may occur in younger children. Skin lesions known as rose spots may be present. Classical cases have fever, myalgia, anorexia, abdominal discomfort and headaches the fever increases step-wise over a period of days and then may remain at 102☏ to 106☏ over 10 to 14 days before decreasing in a step-wise manner. The clinical presentation of typhoid fever exhibits a broad range of severity and can be debilitating. S typhi organisms efficiently invade the human intestinal mucosae ultimately leading to bacteremia following a typical 10- to 14-day incubation period, a systemic illness occurs. Humans are the only natural host and reservoir for S typhi infections result from the consumption of food or water that has been contaminated by the excretions of an acute case or a carrier. Typhoid fever is an infectious disease caused by S typhi. The vial stopper and the plunger stopper of the syringe are not made with natural rubber latex. Each dose of 0.5 mL is formulated to contain 25 mcg of purified Vi polysaccharide in a colorless isotonic phosphate buffered saline (pH 7 ± 0.3), 4.150 mg of Sodium Chloride, 0.065 mg of Disodium Phosphate, 0.023 mg of Monosodium Phosphate, and 0.5 mL of Sterile Water for Injection. The vaccine is a clear, colorless solution. The vaccine contains residual polydimethylsiloxane or fatty-acid ester-based antifoam. Phenol, 0.25%, is added as a preservative. The potency of the purified polysaccharide is assessed by molecular size and O-acetyl content. Each 0.5 mL dose may contain residual amounts of formaldehyde (not more than 100 mcg) used for the inactivation of the bacterial culture. The capsular polysaccharide is precipitated from the concentrated culture supernatant by the addition of hexadecyltrimethylammonium bromide, and the product is purified by differential centrifugation and precipitation. Casein derived raw materials are used early in manufacturing during the fermentation process. The organism is grown in a semi-synthetic medium. Typhim Vi ®, Typhoid Vi Polysaccharide Vaccine, produced by Sanofi Pasteur SA, for intramuscular use, is a sterile solution containing the cell surface Vi polysaccharide extracted from Salmonella enterica serovar Typhi, S typhi Ty2 strain.
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