Tsutsugamushi Antibody Research Articles

Spontaneous splenic rupture associated with scrub typhus: a case report

BackgroundScrub typhus, an acute febrile disease with mild to severe, life-threatening manifestations, potentially presents with a variety of complications, including pneumonia, acute respiratory distress syndrome, cardiac arrhythmias (such as atrial fibrillation), myocarditis, shock, peptic ulcer, gastrointestinal bleeding, meningitis, encephalitis, and renal failure. Of the various complications associated with scrub typhus, splenic rupture has rarely been reported, and its mechanisms are unknown. This study reports a case of scrub typhus-related spontaneous splenic rupture and identifies possible mechanisms through the gross and histopathologic findings.Case presentationA 78-year-old man presented to our emergency room with a 5-day history of fever and skin rash. On physical examination, eschar was observed on the left upper abdominal quadrant. The abdomen was not tender, and there was no history of trauma. The Orientia tsutsugamushi antibody titer using the indirect immunofluorescent antibody test was 1:640. On Day 6 of hospitalization, he complained of sudden-onset left upper abdominal quadrant pain and showed mental changes. His vital signs were a blood pressure of 70/40 mmHg, a heart rate pf 140 beats per min, and a respiratory rate of 20 breaths per min, with a temperature of 36.8 °C. There were no signs of gastrointestinal bleeding, such as hematemesis, melena, or hematochezia. Grey Turner's sign was suspected during an abdominal examination. Portable ultrasonography showed retroperitoneal bleeding, so an emergency exploratory laparotomy was performed, leading to a diagnosis of hemoperitoneum due to splenic rupture and a splenectomy. The patient had been taking oral doxycycline (100 mg twice daily) for 6 days; after surgery, this was discontinued, and intravenous azithromycin (500 mg daily) was administered. No arrhythmia associated with azithromycin was observed. However, renal failure with hemodialysis, persistent hyperbilirubinemia, and multiorgan failure occurred. The patient did not recover and died on the fifty-sixth day of hospitalization.ConclusionsClinicians should consider the possibility of splenic rupture in patients with scrub typhus who display sudden-onset abdominal pain and unstable vital signs. In addition, splenic capsular rupture and extra-capsular hemorrhage are thought to be caused by splenomegaly and capsular distention resulting from red blood cell congestion in the red pulp destroying the splenic sinus.Graphical abstract

Scrub typhus hepatitis confirmed by immunohistochemical staining

Scrub typhus is an acute febrile disease caused by Orientia tsutsugamushi (O. tsutsugamushi). We report herein the case of a woman who presented with fever and elevated serum levels of liver enzymes and who was definitively diagnosed with scrub typhus by histopathological examination of liver biopsy specimens, serological tests and nested polymerase chain reaction. Immunohistochemical staining using a monoclonal anti-O. tsutsugamushi antibody showed focally scattered positive immunoreactions in the cytoplasm of some hepatocytes. This case suggests that scrub typhus hepatitis causes mild focal inflammation due to direct liver damage without causing piecemeal necrosis or interface hepatitis. Thus, scrub typhus hepatitis differs from acute viral hepatitis secondary to liver damage due to host immune responses, which causes severe lobular disarray with diffuse hepatocytic degeneration, necrosis and apoptosis as well as findings indicative of hepatic cholestasis, such as hepatic bile plugs or brown pigmentation of hepatocytes.

Two Cases of Scrub Typhus Presenting with Guillain-Barré Syndrome with Respiratory Failure

Two Cases of Scrub Typhus Presenting with Guillain-Barré Syndrome with Respiratory Failure

A serosurvey of Orientia tsutsugamushi from patients with scrub typhus

AbstractMany countries where scrub typhus is endemic use their own cutoff values for antibody titres to differentiate between cured cases and current infections. To establish an antibody titre cutoff value, one needs to investigate the seroprevalence in endemic areas, and the duration of the increase in titre after complete cure. We conducted a follow-up study of anti-Orientia tsutsugamushi antibody titres using indirect immunofluorescence assays (IFA) and passive haemagglutination assays (PHA) in patients with scrub typhus. After the onset of symptoms, IgM antibody titres increased gradually over 2–3 weeks, peaked at about 4 weeks, and started to decrease rapidly between 4 and 5 weeks. At 1-year follow-up, the median IgM value was 1:10. Out of 77 patients who were tested at that time, 36 (47%) had IgM titres ≥1:20, and none had titres exceeding 1:80. Over the first 2 weeks, IgG antibody titres increased sharply, peaked at about 4 weeks and decreased rather gradually thereafter, with a median titre of 1:128 maintained up to the 18th month. At 1-year follow-up, five out of 77 patients (6.5%) had titres ≥1:1,024 and 57% had titres ≥1:128. Based on these results, a cutoff value of ≥1:160 for IgM antibody should differentiate between previous and current infections in endemic areas such as Korea and Japan, where scrub typhus occurs mainly in the autumn.

Massive small bowel bleeding caused by scrub typhus in Korea

A 79-year-old man was diagnosed with scrub typhus based on fever, eschar, skin rash and a markedly elevated serum tsutsugamushi antibody and doxycycline was started. Five days later, hematochezia developed and multiple small bowel ulcerations with hemorrhage were seen on colonoscopy. Despite intensive therapy, the massive hematochezia worsened and the distal small bowel was resected. Multiple ulcerated lesions were identified pathologically as vasculitis caused by scrub typhus. This is the first reported case of pathologically proven small bowel involvement in scrub typhus infection.

Failed Vertical Transmission of Rickettsia tsutsugamushi (Rickettsiales: Rickettsiaceae) Acquired from Rickettsemic Mice by Leptotrombidium pallidum (Acari: Trombiculidae)

Larvae of Leptotrombidium pallidum (Nagayo, Miyagawa, Mitamura & Tamiya) from uninfected laboratory colonies were fed on mice infected with Rickettsia tsutsugamushi (Hayashi) Ogata. Infection of the chiggers with R. tsutsugamushi was determined by passage of chigger exudates into ddY mice. The passage method was modified so that an inoculum was considered to be positive when R. tsutsugamushi or anti-R. tsutsugamushi antibody, or both, were detected in mice up to the third blind passage. R. tsutsugamushi was detected in six of 18 larvae (33.3%) and in all developmental stages. In adults, five of 18 males and 10 of 46 females were infected with R. tsutsugamushi. In L. fuji (Kuwata, Berge & Philip), R. tsutsugamushi was not found in 57 engorged larvae fed on rickettsemic mice but was found in a very low percentage of deutonymphs and adults. Female L. pallidum from larvae fed on infected mice were paired individually, and F1 larvae were collected. Although eight females were found to be positive for R. tsutsugamushi, the rickettsia was not detected in 12 pools (249 larvae) of F1 larvae from these infected females. We concluded that uninfected mites became infected by feeding on rickettsemic mice at comparatively high rates depending on the species and transmitted this infection transstadially to succeeding life stages, but not vertically to larvae in the following F1 generation.

Serodiagnosis of scrub typhus with antigens immobilized on nitrocellulose sheet

This study was designed to develop a simple method for serodiagnosis of scrub typhus. The basis of the method is detection of anti-Rickettsia tsutsugamushi antibody in patient serum by reaction with antigens dot blotted on a nitrocellulose sheet (NCS). The final evaluation of the reaction is performed by observing the color intensity which develops as a result of sequential treatments of the NCS with peroxidase-conjugated anti-human immunoglobulin G or immunoglobulin M antibody and with the substrate of the enzyme. After various trials, we found that the best results were obtained by using a purified antigen which adhered to an NCS at 0.2 to 2 micrograms of protein per dot and a test serum diluted 1,000- to 4,000-fold. Under these conditions, almost all antibody-positive sera showed a distinct color at the dot on the NCS, so that a positive reaction could be distinguished by the naked eye from a negative reaction with antibody-negative sera, which developed only a faint color. A comparison of the results of screening of antibody-positive and -negative sera by this method and the immunofluorescence test showed that both methods produced similar results. From these results, it is concluded that this dot immunoassay can be useful for the serodiagnosis of scrub typhus.

Epidemiological Studies on the Background of the Endemic Occurrence of Tsutsugamushi Disease in Toyama Prefecture

With a view to clarifying the actual state of inapparent infection of tsutsugamushi diseases, inhibitants of endemic and nonendemic areas were screened for anti-Rickettsia tsutsugamushi antibody (anti-Rt antibody) by the indirect immunofluorescence test. The anti-Rt antibody-positive rate in the inhabitants of the endemic area (about 50%) was statistically significantly higher than that in the nonendemic area (14.7%). The antibody titer in the inhabitants of the endemic area was 10-160, and the number of inhibitants showing a high antibody titer was 2-4 times larger than that of the nonendemic area. A total of 257 volunteers in the endemic area were analyzed for the changes in anti-Rt antibody titer over 1.5-2 years on an individual basis. An increase in the antibody titer was found in 20 inhabitants. There was no difference in the anti-Rt antibody-positive rate between male and female in either the endemic or the nonendemic area. The positive rate was also compared as to the distribution by 10 years of age. In the endemic area, there were no significant differences in the positive rate between any pair of 10-year age groups from 30s to 60s, whereas in the nonendemic area, the positive rate in the teen-age group was significantly lower than those in the age groups of 20 years or older. In Yamada district, the numbers of serum samples obtained from each age group were about the same, and the distribution of the positive rates showed a normal distribution. The nurse students having their homes in Toyama Prefecture were plotted on the map as for their anti-Rt antibody and geographical distribution. The results showed that many of them having homes in the endemic area were positive for the antibody, while some antibody-positives were scattered all over Toyama Prefecture.

Serodiagnosis of tsutsugamushi fever (scrub typhus) by the indirect immunoperoxidase technique.

The indirect immunoperoxidase technique was assessed for the serodiagnosis of tsutsugamushi fever (scrub typhus). The antigens were peritoneal smears prepared from mice infected intraperitoneally with the Karp, Kato, and Gilliam strains of Rickettsia tsutsugamushi. Treatment of the mice with cyclophosphamide apparently increased the number of the rickettsiae, and it minimized the exudate that interfered with the specific staining. The rickettsiae were seen as clusters in the juxtanuclear region of the mesothelial cells and also as free particles outside of the cells. By the indirect immunoperoxidase technique, the sera from all of the patients (49 samples from 30 patients) were positive for the R. tsutsugamushi antibody. The antibody titers (immunoglobulin G [IgG] and IgM) determined by the indirect immunoperoxidase technique correlated with those determined by the indirect immunofluorescence technique. Thus, the indirect immunoperoxidase technique was useful for quantifying both IgG and IgM antibodies to the rickettsia.

Shichito fever in Izu Shichito Islands. 4. Incidence of anti-R. tsutsugamushi antibody among inhabitant's sera (author's transl)

Shichito fever in Izu Shichito Islands. 4. Incidence of anti-R. tsutsugamushi antibody among inhabitant's sera (author's transl)