Epidemic and endemic typhus

Epidemic Typhus:

Epidemic typhus, also known as louse-borne typhus, is caused by Rickettsia prowazekii and is an acute infectious disease transmitted by human lice.

The source of infection is patients or asymptomatic carriers. Human lice act as the transmission vector, carrying Rickettsia prowazekii in their feces. The bacteria enter the bloodstream through skin abrasions, creating a "human-louse-human" infection cycle. Infection can also occur through inhalation of aerosols or ingestion of food contaminated by the pathogen. The general population is generally susceptible, and immunity is acquired after illness. The incubation period is five to 23 days, averaging 10 to 14 days. Clinical manifestations include abrupt onset, severe headache, rash and central nervous system symptoms.

Preventive measures mainly involve improving living conditions, maintaining good hygiene practices, and enhancing the overall resistance of the population. Once patients are identified, louse eradication measures should be implemented, with repetition after seven to 10 days.

Endemic Typhus:

Endemic typhus, caused by Rickettsia mooseri, is an acute infectious disease transmitted by fleas. The primary source of infection is rodents, commonly brown rats and yellow-necked mice. The main vector is the rat flea, and the infection cycle is "rodent-flea-human”.

Infection can occur through inhalation of aerosols or ingestion of food contaminated by the pathogen. The general population is generally susceptible, and the incubation period is five to 15 days.

Clinical manifestations include fever, headache, anorexia and a body temperature typically ranging from 39 to 40 C. Fever may be relapsing or remittent, accompanied by general body aches, conjunctival congestion, and, in some cases, rash, hepatosplenomegaly, and joint symptoms. Rash usually appears on days four to seven, starting on the chest and abdomen and spreading to other areas within 24 hours, including the back, shoulders, arms, legs, face and neck.

Preventive measures involve improving living conditions, maintaining good hygiene practices, rodent and flea control, and enhancing population resistance.