Eiichiro Sando

Serological Cross-Reactivity among Orientia tsutsugamushi Serotypes but Not with Rickettsia japonica in Japan

The rickettsial diseases Japanese spotted fever (JSF) and scrub typhus (ST) are caused by Rickettsia japonica and Orientia tsutsugamushi, respectively. The diseases share clinical symptoms, such as fever, rash, and eschar. However, there are no systematical investigations of the serological cross-reactivity between R. japonica and O. tsutsugamushi. Also, the serological cross-reactivity among O. tsutsugamushi serotypes is still unclear. We analyzed 1406 cases tested by indirect immunoperoxidase assay using seven rickettsial antigens—one R. japonica and six O. tsutsugamushi serotypes—between 2003 and 2016 at two reference centers in Japan. Of these, 167 JSF and 190 ST cases were serologically diagnosed. None of the ST cases had a significant increase in IgM titers against R. japonica. Six JSF cases showed IgG titers of ≥40 against O. tsutsugamushi, but no IgG titer showed a significant elevation in the convalescent phase sample. We observed a substantial degree of cross-reactivity between O. tsutsugamushi serotypes. Cross-reactivity was significant among Karp, Hirano/Kuroki, and Kato types and between Gilliam and Irie/Kawasaki types in IgM, while the Shimokoshi type was less cross-reactive than the others. In conclusion, there is no serological cross-reaction between R. japonica and O. tsutsugamushi. The cross-reactivity among O. tsutsugamushi varies depending on serotypes.

Correction: Sando E. et al. Serological Cross-Reactivity among Orientia tsutsugamushi Serotypes but Not with Rickettsia japonica in Japan. Trop. Med. Infect. Dis. 2018, 3, 74.

The authors wish to make the following corrections to this paper [...].

Distinguishing Japanese Spotted Fever and Scrub Typhus, Central Japan, 2004– 2015

Japanese spotted fever (JSF) and scrub typhus (ST) are endemic to Japan and share similar clinical features. To document the clinical and epidemiologic characteristics that distinguish these 2 rickettsial diseases, during 2004–2015 we recruited 31 JSF patients, 188 ST patients, and 97 nonrickettsial disease patients from the southern Boso Peninsula of Japan. JSF occurred during April–October and ST during November–December. Patients with JSF and ST were significantly older and more likely to reside in wooded areas than were patients with nonrickettsial diseases. Spatial analyses revealed that JSF and ST clusters rarely overlapped. Clinical findings more frequently observed in JSF than in ST patients were purpura, palmar/plantar rash, hyponatremia, organ damage, and delayed defervescence after treatment. Although their clinical features are similar, JSF and ST differ in seasonality, geographic distribution, physical signs, and severity. Because a considerable percentage of patients did not notice rash and eschar, many rickettsial diseases might be underdiagnosed in Japan.

Case Report: Concurrent Sympatric Scrub Typhus and Japanese Spotted Fever in Japan

Scrub typhus and Japanese spotted fever-both rickettsial diseases-are endemic and notifiable in Japan and may cause a fatal outcome without prompt treatment. Here we present the first case of a concurrent sympatric infection of both diseases with grade II evidence. A 67-year-old woman, after a single event of potential exposure to the pathogens, presented with a 12-day history of fever, pharyngeal pain, papulo-erythematous rash, and pronounced fatigue. Her erythematous rash was distributed on her trunk and extremities, palms, and soles and eventually progressed to purpura. Fever persisted until doxycycline was administered on day 12. A significant > 4-fold increase in immunoglobulin G and immunoglobulin M titers against multiple serotypes of Orientia tsutsugamushi and Rickettsia japonica were revealed by indirect immunoperoxidase assays. These clinical and serological data, even in the absence of molecular or isolation evidence, provided grade II evidence that this was a concurrent infection of sympatric scrub typhus and Japanese spotted fever.

Influenza Vaccine Effectiveness Against Influenza-Associated Pneumonia and Pneumococcal Pneumonia in Older Adults: A Prospective Test-Negative Design Study

Abstract Background Studies have shown that influenza vaccines are effective in preventing influenza-associated acute respiratory illnesses in older adults. However, the influenza vaccine effectiveness (IVE) against influenza-associated pneumonia in this age group has not been established. No study has formally investigated the IVE against pneumococcal pneumonia. Methods This study was conducted as part of a multicenter prospective investigation of adult pneumonia by the Adult Pneumonia Study Group-Japan (APSG-J). All community-onset pneumonia patients aged 65 years or older who visited a community-based hospital in Chiba, central Japan were enrolled to the study from December 2012 to January 2014. Sputum samples were tested for 13 viruses and 6 bacteria by multiplex PCR assays. Patients were diagnosed as influenza-associated pneumonia if sputum PCR assays were positive for influenza A or B. Patients were diagnosed as pneumococcal pneumonia if sputum culture yielded pneumococcus, sputum PCR assays were positive for both ply and lytA genes, or a urinary antigen test showed a positive result. Patients were considered vaccinated if they had received at least one dose of seasonal inactivated influenza vaccine in the 12 months before the hospital visit. A test-negative design was applied to estimate the IVE for influenza-associated pneumonia and pneumococcal pneumonia. IVEs were calculated as (1 – odds ratio) × 100%. Results A total of 1044 patients were enrolled to the study. Among them, 49 (4.7%) were influenza-associated pneumonia, and 168 (16.1%) were pneumococcal pneumonia. The adjusted IVE against influenza-associated pneumonia was 57.2% (95% CI, 17.9% to 76.8%). The adjusted IVE against pneumococcal pneumonia was 31.7% (0.6% to 53.1%); the estimate did not change before and after controlling for pneumococcal vaccination history. Conclusion Influenza vaccines effectively prevent influenza-associated pneumonia in older adults. Influenza vaccines are also associated with decreased risk of pneumococcal pneumonia in this age group, while some residual confounding may remain. Disclosures All authors: No reported disclosures.

A case of tracheo-innominate artery fistula successfully treated with endovascular stent of the innominate artery

Tracheo‐innominate artery fistula (TIF) is a rare but life‐threatening complication of tracheostomy. We describe a 44‐year‐old man who was admitted for a pressure ulcer infection with a third tracheostomy in place. He showed massive hemoptysis from the TIF, followed by cardiopulmonary arrest. The cuff of the tube was hyperinflated; however, even a slight movement of the tube resulted in recurrent massive hemorrhage. Thus, an endovascular stent graft was placed. Our case shows that sentinel bleeding may be found prior to TIF, and an endovascular repair can be a lifesaving temporizing option, when the hemorrhage was not controlled by hyperinflating the cuff of the tube.