What Causes Typhoid Fever?

Typhoid fever caused by typhoid bacillus, patients with persistent high fever (40 to 41 ° C) for more than 1 to 2 weeks in the typhoid epidemic season and regions, and have a special poisoned face, relatively slow pulse, skin roseola, hepatosplenomegaly The total number of white blood cells in peripheral blood is low, eosinophils disappear, and typhoid cells (ring cells) are present in bone marrow, which can be clinically diagnosed as typhoid fever.

Basic Information

English name: typhoid fever
Visiting department: Infectious Diseases

Common causes: Caused by Salmonella typhi
Common symptoms: High fever, poisoned face, slow pulse, skin roseola, liver and spleen
Contagious: Have

Causes of typhoid fever

Typhoid bacillus has a strong viability in nature, can survive in water for 2 to 3 weeks, can maintain in the feces for 1 to 2 months, not only can survive in milk, but can reproduce. Low temperature resistance, can survive for several months in a frozen environment, but weak resistance to light, heat, drying and disinfectant, die in direct sunlight for several hours, die after heating to 60 for 30 minutes or immediately after boiling, disinfection and drinking water Chlorine can kill quickly.

Clinical manifestations of typhoid fever

The incubation period is about 10 days, and its length is related to the amount of infected bacteria. The outbreak of food-type outbreaks can be as short as 48 hours, while the outbreak of water-borne outbreaks can be as long as 30 days. The typical natural course of typhoid fever is about 4 weeks, which can be divided into 4 stages:

Initial stage

It is equivalent to the first week of the disease course. Onset is mostly slow. Fever is the earliest symptom. It is often accompanied by general discomfort, fatigue, loss of appetite, sore throat, and cough. The condition gradually worsened, and the body temperature rose stepwise, reaching 39 to 40 ° C within 5 to 7 days. There may be chills and fewer chills before fever, and sweating is not significant when fever is reduced.

Extreme

It is equivalent to the second to third week of the disease course, and often has the typical manifestations of typhoid fever, which is helpful for diagnosis.

3. Remission period

Corresponding to the 3rd to 4th weeks of the disease course, the human body's resistance to typhoid bacteria gradually increased, body temperature fluctuated and began to decline, appetite gradually improved, abdominal distension gradually disappeared, and splenomegaly began to retract. However, during this period, there is a risk of intestinal bleeding or intestinal perforation, and special vigilance is required.

4. Recovery period

The course began on the 4th weekend, the body temperature returned to normal, and the appetite improved, and generally recovered completely in about 1 month.

Typhoid examination

Routine inspection

Most white blood cells are 3 × 10 ⁹ / L 4 × 10 ⁹ / L, with neutropenia and eosinophils disappearing. The eosinophils in the polar phase are> 2%, and those with an absolute count exceeding 4 × 10 ⁸ / L can basically exclude typhoid fever. Mild proteinuria may be present at high fever. Fecal occult blood test was positive.

2. Bacteriological examination

(1) Blood culture is the basis for diagnosis. It can be positive early in the course of the disease, and the positive rate can reach 90% on the 7th to 10th days, and it can be reduced to 30% to 40% in the third week, and often negative in the fourth week;

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

(3) The fecal culture can be positive during the incubation period, up to 80% at 3 to 4 weeks, and the positive rate drops rapidly at 6 weeks after illness, and 3% of patients can excrete bacteria for more than one year;

(4) The positive rate at the later stage of the course of urine culture can reach 25%, but fecal contamination should be avoided;

(5) Rose rashes can also be positive cultured by scrapings or biopsy sections.

Typhoid diagnosis

Typhoid fever can be diagnosed based on epidemiological data, clinical manifestations and immunological examination results, but the diagnosis of typhoid fever is based on the detection of pathogenic bacteria:

1. Clinical diagnostic criteria: In the epidemic season and regions, there is persistent high fever (40 to 41 ° C) for more than 1 to 2 weeks, and there is a special poisoned face, relatively slow pulse, skin roseola, hepatosplenomegaly, and peripheral blood. The total number of white blood cells is low, eosinophils disappear, and there are typhoid cells (ring cells) in the bone marrow, which can be clinically diagnosed as typhoid fever.

2. Isolated typhoid bacteria from blood, bone marrow, urine, feces, and roseola scrapes.

3. The specific antibody is positive, the "O" antibody agglutination titer 1:80, the "H" antibody agglutination titer 1: 160, and the recovery period titer is increased by more than 4 times.

Typhoid treatment

General treatment and symptomatic treatment. After admission, patients are isolated according to infectious diseases of the digestive tract. After clinical symptoms disappear, they are sent to stool culture every 5-7 days, and the isolation can be released 2 times in a row. Patients with fever must rest in bed. They can sit in bed for 2 to 3 days after fever, and can move slightly for 2 weeks after fever. Should be given a high-calorie, high-nutrition, digestible diet, including a sufficient amount of carbohydrates, proteins and various vitamins to supplement the consumption during the fever period to promote recovery, during the fever should be a liquid or soft residue-free diet, a small number of meals. After fever, after appetite increases, you can gradually add porridge, soft rice, avoid eating hard and slag food, so as to avoid intestinal bleeding and intestinal perforation. Generally, the normal diet is restored 2 weeks after fever. Patients should be encouraged to take in more water, about 2,000 to 3,000 ml (including diet) daily to facilitate excretion of toxins. Those who cannot eat due to severe illness can use intravenous drip of 5% glucose saline.

Those with severe toxemia can use hormones in combination with a sufficient amount of effective antibacterial therapy.