paratyphoid fever

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Related to paratyphoid fever: enteric fever

Paratyphoid Fever



Paratyphoid fever, which is sometimes called Salmonella paratyphi infection, is a serious contagious disease caused by a gram-negative bacterium. It is also grouped together with typhoid fever under the name enteric fever.


Enteric fever is increasingly rare in the United States. Of the 500 cases reported in an average year, about 60% are infections acquired during travel in Mexico, India, or South America.
Paratyphoid fever has three stages: an early stage marked by high fever; a toxic stage with abdominal pain and intestinal symptoms, and a long period of recovery from fever (defervescence). In adults, these three phases may cover a period of four to six weeks; in children, they are shorter and may cover 10 days to two weeks. During the toxic stage there is a 1-10% chance of intestinal perforation or hemorrhage.

Causes and symptoms

Paratyphoid fever is caused by any of three strains of Salmonella paratyphi: S. paratyphi A; S. schottmuelleri (also called S. paratyphi C); or S. hirschfeldii (also called S. paratyphi B). It can be transmitted from animals or animal products to humans or from person to person. The incubation period is one to two weeks but is often shorter in children. Symptom onset may be gradual in adults but is often sudden in children.
Paratyphoid fever is marked by high fever, headache, loss of appetite, vomiting, and constipation or diarrhea. The patient typically develops an enlarged spleen. About 30% of patients have rose spots on the front of the chest during the first week of illness. The rose spots develop into small hemorrhages that may be hard to see in African or Native Americans.
Patients with intestinal complications have symptoms resembling those of appendicitis: intense cramping pain with soreness in the right lower quadrant of the abdomen.


The diagnosis is usually made on the basis of a history of recent travel and culturing the paratyphoid organism. Because the disease is unusual in the United States, the doctor may not consider paratyphoid in the diagnosis unless the patient has the classic symptoms of an enlarged spleen and rose spots. The doctor will need to rule out other diseases with high fevers, including typhus, brucellosis, tularemia (rabbit fever), psittacosis (parrot fever), mononucleosis, and Kawasaki syndrome. S. paratyphi is easily cultured from samples of blood, stool, urine, or bone marrow.



Paratyphoid fever is treated with antibiotics over a two- to three-week period with trimethoprimsulfamethoxazole (Bactrim, Septra); amoxicillin (Amoxil, Novamoxin); and ampicillin (Amcill). Thirdgeneration cephalosporins (ceftriaxone [Rocephin], cefotaxime [Claforan], or cefixime [Suprax]) or chloramphenicol (Chloromycetin) may be given if the specific strain is resistant to other antibiotics.


Patients with intestinal perforation or hemorrhage may need surgery if the infection cannot be controlled by antibiotics.

Supportive care

Patients with paratyphoid fever need careful monitoring for signs of complications as well as bed rest and nutritional support. Patients with severe infections may require fluid replacement or blood transfusions.


Most patients with paratyphoid fever recover completely, although intestinal complications can result in death. With early treatment, the mortality rate is less than 1%.



Vaccination against paratyphoid fever is not necessary within the United States but is recommended for travel to countries with high rates of enteric fever.

Hygienic measures

Travelers in countries with high rates of paratyphoid fever should be careful to wash hands before eating and to avoid meat, egg, or poultry dishes unless they have been thoroughly cooked.

Key terms

Defervescence — Return to normal body temperature after high fever.
Enteric fever — A term that is sometimes used for either typhoid or paratyphoid fever.
Rose spots — Small slightly raised reddish pimples that are a distinguishing feature of typhoid or paratyphoid infection.



Fauci, Anthony S., et al., editors. Harrison's Principles of Internal Medicine. New York: McGraw-Hill, 1997.


1. resembling typhoid fever.
paratyphoid fever infection caused by Salmonella of all groups except S. typhosa. The disease is usually milder than typhoid fever and has a shorter incubation period, more abrupt onset, and a lower mortality rate. Clinically and pathologically, however, the two diseases cannot be distinguished.

par·a·ty·phoid fe·ver

an acute infectious disease with symptoms and lesions resembling those of typhoid fever, although milder in character; associated with the presence of the paratyphoid organism of which at least three varieties (types A, B, and C) have been described.
Synonym(s): paratyphoid

paratyphoid fever

An acute intestinal disease of humans, similar to typhoid fever but usually less severe, caused by ingesting food or water contaminated with salmonella bacteria having the serotype Paratyphi.

paratyphoid fever

Etymology: Gk, para + typhos, stupor, eidos, form; L, febris, fever
a bacterial infection, caused by any Salmonella species other than S. typhi, characterized by symptoms resembling typhoid fever, although somewhat milder. See also rose spots, Salmonella, salmonellosis, typhoid fever.

par·a·ty·phoid fe·ver

, paratyphoid (par'ă-tī'foyd fē'vĕr)
An acute infectious disease with symptoms and lesions resembling those of typhoid fever, although milder in character; associated with the presence of the paratyphoid organism, of which at least three varieties (types A, B, and C) have been described.

paratyphoid fever

An infectious disease, closely similar to but milder than, TYPHOID. It is caused by the organism Salmonella paratyphi and is spread in the same ways as Salmonella typhi .


(Schottmüller), Hugo A.G., German physician, 1867-1936.
Schottmueller bacillus - a species causing enteric fever. Synonym(s): Salmonella schottmulleri
Schottmueller disease - an acute infectious disease with symptoms and lesions resembling those of typhoid fever. Synonym(s): paratyphoid fever

par·a·ty·phoid fe·ver

, paratyphoid (par'ă-tī'foyd fē'vĕr)
Acute infectious disease with symptoms and lesions resembling those of typhoid fever, although milder in character.
References in periodicals archive ?
In summary, we identified the evolution and transmission mode of paratyphoid fever in the China provinces where incidence is highest.
Ty21a live oral typhoid vaccine and prevention of paratyphoid fever caused by Salmonella enterica Serovar Paratyphi B.
Asia was the most common destination for acquisition of campylobacteriosis (37%), cholera (100%), cryptosporidiosis (49%), paratyphoid fever (100%), shigellosis (54%), typhoid fever (89%) and Vibrio para haemolyticus infection (71%).
Typhoid and paratyphoid fever are particularly prevalent in India and Asia and travellers to high-risk destinations should receive typhoid vaccination.
This outbreak highlights the urgent need for a paratyphoid fever vaccine; although typhoid fever vaccines exist, persons living in and visiting regions of active Paratyphi A transmission have no alternative to relying exclusively on close attention to food and water safety to mitigate risk (4).
To the Editor: In cases of typhoid and paratyphoid fever, it is often necessary to commence treatment before the results of laboratory sensitivity tests are available.
Paratyphoid fever is a major clinical problem in India, but large outbreaks were not reported until 1996 (2).
Sood S, Kapil A, Dash N, Das BK, Goel V, Seth R Paratyphoid fever in India: an emerging problem.
To the Editor: Fluoroquinolones have been the drug of choice for treating typhoid and paratyphoid fever since the beginning of the 1990s.
Many other rampant infectious diseases such as cholera, typhoid and paratyphoid fevers, shigellosis, amoebiasis, cysticercosis, viral hepatitis (A, B, C, E), influenza, brucellosis, hydatidosis, paragonimiasis, rabies, Leptospirosis, anthrax, scrub typhus etc.
Typhoid and Paratyphoid Fevers and Other Salmonella Infections;