What is epidemic typhus?

What is epidemic typhus?

What is epidemic typhus?

Epidemic typhus, also known as typhus typhus or "typical typhus", may occur after several months to several years after epidemic typhus, known as recurrent typhus, also known as Brill-Zinsser disease. It is an acute infectious disease transmitted by Platts rickettsia through body lice. The clinical features of epidemic typhus are persistent high fever, headache, rash-like rash (or maculopapular rash) and central nervous system symptoms. The natural course is 2 to 3 weeks. Rickettsia was discovered in 1910 by Ricketts in the blood of patients with typhus. In 1913, Prowazekii also found pathogens from patients with neutrophils; both of them were sacrificing typhus. To commemorate them, the pathogen of epidemic typhus was named as Platts.

Clinical manifestations of epidemic typhus

Epidemic typhus can be divided into two types, typical and light, and recurrent typhus.

1. Typical epidemic typhus incubation period is 5 to 21 days, with an average of 10 to 12 days. A small number of patients have prodromal symptoms of 2 to 3 days, such as fatigue, headache, dizziness, chills, and low fever. Most of the onset of illness, accompanied by chills, severe and persistent headache, muscle pain in the body, conjunctiva and facial congestion.

• Fever The epidemic typhus body temperature reached the peak on the 2nd to 4th day (102~104℉ or above), and the first week showed a retention pattern, and there was a relaxation trend from the 2nd week. The epidemic typhus fever usually takes 14 to 18 days, and the heat quickly returns to normal within 2 to 4 days. Among the cases reported in recent years, the heat type is mostly relaxation or irregularity, which may be related to the application of antibiotics.
• Rash is an important epidemic typhus sign, seen in more than 80% of cases, appeared on the 4th to 6th day of the disease, first seen in the chest, back, armpits, upper arms, etc., rapidly developed throughout the day to the whole body . Epidemic typhus usually has no rash on the face and less rash on the lower extremities. The rash is round or oval, with a diameter of about 2 to 4 mm. It is initially a bright red maculopapular rash, which fades, and then turns into a dark red or a sputum. The rash subsides in 5 to 7 days, and the rash can last for 1 to 2 weeks, with brown spots or desquamation.
• The symptoms of the nervous system are obvious and appear very early. The epidemic typhus manifests as panic, excitement, and severe headache. It can be accompanied by mental retardation, paralysis, occasional meningeal irritation, muscle and tongue tremor, coma, and size. Incontinence, difficulty swallowing, hearing loss, etc.
• Cardiovascular symptoms Epidemiological typhus typhoid heart rate growth rate is generally proportional to the increase in body temperature, there may be galloping, arrhythmia and other toxic myocarditis. Shock or hypotension is a combined consequence of loss of water, microcirculatory disorders, cardiovascular and adrenal insufficiency.

2. Light weight In recent years, patients with mild epidemic typhus are more common in the country, which may be related to the level of immunization in the population. The characteristics of mild epidemic typhus are:

• The heat stroke is short (8-9 days) and the heat is low (about 102℉);
• The symptoms of venom are mild, but there is still obvious pain in the whole body;
• Rash is a congestive maculopapular rash, found in the chest, abdomen, no rash also accounted for a certain proportion;
• Nervous system symptoms are mild, short duration, mainly manifested as headache, excitement, etc.;
• Hepatosplenomegaly is rare.

3. Recurrent typhus typhus Also known as Brill-Zinsser disease, foreigners are more common in Eastern Europe and Eastern European countries who migrate to the United States. There are few reports of recurrent epidemic typhus in China. The main clinical manifestations can be summarized as:

• Is mild, mild symptoms of toxemia and central nervous system;
• Is a relaxation heat, the heat range is 7 to 11 days;
• No rash, or only rare maculopapular rash;
• Sporadic, no seasonality, the incidence rate of the older age group was significantly higher.