Persistence of Rickettsia Tsutsugamushi in Tissues of Patients Recovered From Scrub Typhus1

Unresolved Problems Related to Scrub Typhus: A Seriously Neglected Life-Threatening Disease

“…Another unresolved topic is the prevalence and pathologic effects of persistent Orientia infection. 72,73 Persistent infection by Orientia was first described in experimentally infected mice, and bacteria could be detected by inoculation of blood or homogenized tissue of previously infected mice for up to 610 days after the infection. 74,75 Smadel and others 72 showed that, 2 years after scrub typhus, O. tsutsugamushi could be isolated from the lymph node of an asymptomatic person.…”

“…The agent was infectious for intraperitoneally inoculated mice with a lethal outcome. 72 More recently, Chung and others 73 isolated Orientia from the blood of six individuals who had scrub typhus 1-18 months earlier. The factors that allow for persistent Orientia infection are another unresolved topic in scrub typhus research.…”

The Nature of Immunity Against Scrub Typhus in Mice I. The Resistance of Mice, Surviving Subcutaneous Infection of Scrub Typhus Rickettsia, to Intraperitoneal Reinfection of the Same Agent

“…The resistance of these animals to reinfection may be directly or indirectly caused by the persistence of rickettsia in the tissues of those animals, namely, infection immunity or premunition (Parrot and Parrot, 1949). Smadel et al (1952) have shown that Rickettsia orientalis persists in the tissues of patients who recovered from scrub typhus for a considerable time, and found a certain correlation between the resistance of the individuals and the persistence of rickettsia in their tissues.…”

Rickettsia Tsutsugamushi Antibody in Mother/Cord Pairs of Sera

“…Rickettsia tsutsugamushi, the agent of scrub typhus, is another rickettsial agent that causes persistent infections following recovery from acute disease (Kouwenaar and Esseveld, 1949;Smadel et al, 1952;Shirai et al, 1979). Because such persistence in pregnant women could lead to fetal infections, we studied the IgM and IgG levels in the sera of mother and umbilical cord (mother/cord) pairs from a population known to have a high prevalence of scrub typhus infection.…”