Paratyphoid A

Introduction to paratyphoid A Paratyphoid A is an intestinal infectious disease that can be spread by the spread of domestic water, food, flies, and cockroaches. Symptoms: There is general malaise, poor appetite, headache, fever, body temperature can reach 40 °C within 5-6 days, continuous retreat, dull expression, red rash on the chest and abdomen, hepatosplenomegaly, mild It can be tender, and may have complications such as intestinal bleeding, intestinal perforation, and myocarditis. The mortality rate of patients with comorbidities is high. basic knowledge The proportion of illness: 0.0025% Susceptible people: no specific population Mode of infection: respiratory transmission Complications: osteomyelitis endocarditis pericarditis

Cause of paratyphoid A

There are three pathogens of paratyphoid fever:

The pathogen of a pair of typhoid A is A. paratyphi A, or Salmonella paratyphimurium;

The pathogen of 2 typhoid fever B is Escherichia coli, or Salmonella paratyphimurium;

The pathogen of the three typhoid fever C is C. parahaemolyticus, or Salmonella paratyphimurium. The above three bacilli belong to the A, B, and C groups of Salmonella, and can be classified according to the phage typing method. Both parahaemolyticus have "O" and "H" antigens, of which C. parahaemolyticus also has "Vi" antigen. Under natural conditions, paratyphoid bacillus can only infect humans.

When the body's immunity is low and the resistance is reduced, the body is infected by the bacteria after passing through the environment or after contacting the patient, causing symptoms of paratyphoid fever.

Paratyphoid A prevention

In the daily life, prevention of paratyphoid should pay attention to food hygiene, and put a good "disease into the mouth":

1, do not eat raw or half-life to eat seafood.

2, do not go to the stalls with poor sanitation, restaurants to eat.

3, develop good hygiene habits, do not drink raw water, wash hands before and after meals.

4, patients with unexplained persistent fever, should go to the hospital for diagnosis and treatment in time, so as not to delay the disease.

5, when there are typhoid patients in and around the home, it is necessary to pay attention to self-protection. For potentially contaminated items, use boiling, disinfectant soaking, etc. to disinfect.

6, emergency prevention medication, available compound sulfamethoxazole 2 tablets, twice a day, taking 3-5 days.

7. Emergency vaccination: vaccination against typhoid vaccine for key populations in outbreak areas and adjacent areas.

Paratyphoid A complications Complications osteomyelitis endocarditis pericarditis

Complications include arthritis, joint abscess, osteomyelitis, pneumonia, endocarditis, pericarditis and so on.

Symptoms of paratyphoid A common symptoms abdominal pain diarrhea toxemia hyperthermia vomiting splenomegaly rash

The onset is slow, but the sudden rise is not uncommon. At the beginning, there may be acute gastroenteritis symptoms such as abdominal pain, vomiting, diarrhea, etc. After about 2 to 3 days, the symptoms are relieved, and then the body temperature rises, and typhoid-like symptoms appear. Gastrointestinal inflammation is significant, and lasts longer, with paratyphoid B more common, once called "gastrointestinal gastroduodenal paratyphoid", fever often peaks within 3 to 4 days, fluctuations are large, missed heat type is rare Short heat stroke (average 3 weeks for paratyphoid A and 2 weeks for paratyphoid fever B), the symptoms of venom are mild, but the intestinal symptoms are more significant, and relatively slow veins and liver, splenomegaly, and typhoid fever may occur. The rash often appears earlier, can be spread throughout the body and is slightly larger than the typhoid rash and darker (paratyphoid A), but sometimes it is papular (paratyphoid B), recurrence and re-ignition in paratyphoid A, B are more common, especially With paratyphoid A, intestinal bleeding, intestinal perforation are less common, and the mortality rate is lower.

Examination of paratyphoid A

1, routine inspection

Most of the white blood cells are 3×109/L4×109/L with neutropenia and disappearance of eosinophils, and the latter gradually rises with the improvement of the disease. Extremely eosinophils > 2% absolute count over 4 × 108 / L can be basically excluded from typhoid fever. Mild proteinuria in high fever. Fecal occult blood test was positive.

2, bacteriological examination

1 blood culture is the evidence of the diagnosis can be positive in the early stage of the disease, the positive rate of the 7th to 10th day can reach 90%, the third week is reduced to 30% to 40%, the fourth week is often negative;

2 The positive rate of bone marrow culture is higher than that of blood culture, especially suitable for those who have been treated with antibiotics and those with negative blood culture;

3 fecal culture can be positive from the incubation period, up to 80% in the third to fourth weeks, and the positive rate in the 6 weeks after the disease is rapidly decreased by 3%. The patient can be more than one year old;

4 urine culture: the positive rate in the late stage of the disease can reach 25%, but the fecal contamination should be avoided;

5 Rose rash scraping or biopsy sections can also be positively cultured.

3, immunological examination

The fatda test typhoid serum agglutination test, that is, the fat-positive reaction, has an auxiliary diagnostic value for typhoid fever. The antigens used in the examination included typhoid bacillus (O) antigen, flagellar (H) antigen paratyphoid A, B, and propylene flagellin antigens. The five purposes were to determine the agglutination titer of various antibodies in the patient's serum by agglutination. There was not a positive reaction in the first week of the disease. Generally, the positive rate gradually increased from the second week to 90% in the fourth week, and the positive reaction lasted for several months after the recovery. In a small number of patients, antibodies are raised very late or even the antibody duration of the whole course is very low (14.4%) or negative (7.8% to 10%), so the disease cannot be excluded accordingly.

The Widal trial has been used for nearly 100 years. In the 1960s, there was some objection to its specificity. The results showed that there was confusion and confusion. The Widal's test of non-typhoid fever was also positive, such as various acute infections, tumors, connective tissue diseases. Chronic ulcerative colitis of sexually transmitted diseases can have positive results. Perlnan et al believe that sterile colon cells and Enterobacteriaceae may have a common antigen colonic mucosal damage caused by anti-colon antibodies and Salmonella bacterial antigen cross-reaction, so the judgment of the results of the fatda reaction should be cautious, must be closely combined Clinical data should also emphasize the comparison of serum antibody titers during the recovery period. It has been suggested that the positive rate of the popular strain antigen can be increased compared with the international strain. It is recommended to replace the international standard strain with the local epidemic strain to improve the positive rate of typhoid diagnosis in the epidemic area.

Diagnosis and identification of paratyphoid A

Diagnostic criteria

Sometimes it is not easy to identify with typhoid, it must rely on bacterial culture and typhoid agglutination test to confirm the diagnosis.

1. Bacterial culture: The positive rate of blood and bone marrow culture is higher during fever, and the fecal culture is prone to be positive in patients with gastroenteritis. In patients with localized suppuration, pathogens can be detected from the extracted pus.

2, typhoid agglutination test: paratyphoid A, B agglutination titer is higher, but the cost of paratyphoid C is lower, a small number of patients in the course of typhoid agglutination test is always negative.

Differential diagnosis

In the early stage of typhoid fever (within the first week), the characteristic performance has not been revealed and should be differentiated from the following diseases:

1, viral infection: upper respiratory tract virus infection can also have persistent fever, headache, white blood cell count decreased, similar to early typhoid, but such patients are more acute onset, often accompanied by upper respiratory symptoms, often no slow pulse, splenomegaly or Rose rash, typhoid pathogen and serological examination are negative, often self-healing within 1 week.

2, malaria: all types of malaria, especially falciparum malaria is easy to be confused with typhoid fever, but malaria fluctuates daily with large body temperature, with chills or chills before fever, sweating when hot retreat, spleen is slightly harder, anemia is more obvious, peripheral Blood and bone marrow smears can be found in Plasmodium, and rapid antipyretic treatment with effective antimalarial drugs is not effective.

3, leptospirosis: the influenza typhoid type of this disease is very common during the summer and autumn epidemic, acute onset, accompanied by chills and fever, fever is persistent or relaxation type, similar to typhoid, patients have a history of contact with infected water, Conjunctival congestion, body aches, especially pain and tenderness of the gastrocnemius, inguinal lymphadenopathy, etc.; peripheral blood leukocyte count increased, erythrocyte sedimentation rate accelerated, relevant pathogens, serological examination can be confirmed.

4, acute viral hepatitis: acute jaundice hepatitis in the early stage of jaundice fever, general malaise, digestive tract symptoms, leukopenia or normal, not easy to distinguish from typhoid, but this patient has jaundice every 5 to 7 days of the disease, The body temperature also returned to normal, the liver was tender and the liver function was abnormal. It can be diagnosed by serological markers of viral hepatitis. In addition, typhoid fever complicated with toxic hepatitis is also confused with viral hepatitis, but the liver function damage of the former. Relatively light, there are jaundice in the presence of jaundice still fever, and other characteristic manifestations of typhoid, blood culture typhoid can be positive, with the disease improved, liver and liver function return to normal, typhoid fever After the extreme period (week 2), it must be differentiated from the following diseases.

5, sepsis: some Gram-negative bacilli must be differentiated from typhoid fever, this disease may have biliary, urinary tract, intestinal and other primary infections, fever often accompanied by chills, sweating, bleeding tendency, many patients In the early stage, shock can occur and the duration is longer. Although the white blood cells can be normal or slightly lower, but often with the left side of the nucleus, the diagnosis must rely on bacterial culture.

6, miliary tuberculosis: fever is more irregular, often accompanied by night sweats, pulse faster, shortness of breath, cyanosis, etc., history of tuberculosis or close contact with tuberculosis patients, X-ray film shows miliary shadows in the lungs.

7. Brucellosis: There is a history of contact with sick animals or drinking unsterilized cattle, goat milk or dairy products, long-term irregular fever, wave-hot type on the attack, joints, muscle pain and sweating, serum cloth Brucella agglutination test is positive, blood and bone marrow culture can be isolated to Brucella.

8, endemic typhus: onset more urgent, high fever often accompanied by chills, fast pulse, conjunctival congestion and rash, rash appeared earlier (3rd to 5th day), the number is more, the distribution is wider, the color is dark red, There is no retreat, there is pigmentation after rash, the course of disease is about 2 weeks, the number of white blood cells is mostly normal, and the agglutination of proteobacteria is positive. The blood is inoculated into the abdominal cavity of guinea pigs to isolate the rickettsia.

9, tuberculous meningitis: some patients with typhoid can have severe headache, sputum, lethargy, neck resistance and other manifestations of vaginal meningitis, easily confused with tuberculous meningitis, but many patients with tuberculous meningitis With other organ tuberculosis, although there is persistent fever but no rose rash and splenomegaly, headache and neck resistance are more significant, may be accompanied by nystagmus, cranial nerve spasm, etc., without the anti-tuberculosis effect treatment gradually worsened, cerebrospinal fluid examination Comply with tuberculous meningitis changes; cerebrospinal fluid smear, culture, animal vaccination can be found in tuberculosis.

10. Malignant histiocytosis: The pathological feature of this disease is that the tissue cells in the mononuclear-macrophage system are abnormally proliferated and infiltrated, and the clinical manifestations are complex and variable, sometimes mainly characterized by fever, liver, splenomegaly and leukopenia. In addition, there may be tissue cell enlargement and phagocytosis in the typhoid bone marrow tablets, so it is easy to be confused, but the disease progresses rapidly, there is obvious anemia, bleeding symptoms; blood tablets and (or) bone marrow slices have specific malignant tissue Cells and (or) multinucleated giant tissue cells, proliferating tissue cells of different shapes, and can phagocytose red, white blood cells and platelets; peripheral blood seems to have significant whole blood cell reduction, antibacterial therapy is ineffective.

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