Definitive and Indeterminate Pseudomonas aeruginosa Infection in Adults with Community-acquired Pneumonia: A Prospective Observational Study

Rationale: Pneumonia due to Pseudomonas aeruginosa (PA) is associated with high mortality and requires antipseudomonal treatment. Because PA can colonize the respiratory tract, the diagnosis of pathogenic PA involvement is challenging.Objectives: To determine the prevalence of definitive and indeterminate PA infection in community-acquired pneumonia, to describe the clinical and microbiological profiles, and to estimate the burden of unnecessary antipseudomonal drug prescriptions.Methods: We prospectively enrolled 2,701 patients with community-acquired pneumonia. Using stringent criteria for diagnosing PA pneumonia, we generated the following three groups: 1) definitive PA, 2) indeterminate PA, and 3) non-PA pneumonia.Results: The prevalence of definitive PA pneumonia was 0.9% (n = 25), and that of indeterminate PA pneumonia was 4.9% (n = 131). Considerable clinical differences were observed among the groups. Patients with definitive PA pneumonia were more likely to have a history of tuberculosis and chronic obstructive pulmonary disease/bronchiectasis and had a higher 30-day mortality (28%) than patients with non-PA pneumonia. Patients with indeterminate PA pneumonia were more likely to have comorbidities than patients with non-PA pneumonia. More than half of the patients with indeterminate PA and 25% of the patients with non-PA pneumonia were treated with an antipseudomonal drug. No patients with definitive PA pneumonia had multidrug resistance.Conclusions: In this population, the prevalence of community-acquired pneumonia due to PA was low. The clinical features and 30-day mortality rates of patients with indeterminate PA pneumonia were different from those of patients with definitive PA pneumonia. Most of the prescribed antipseudomonal drugs for patients with community-acquired pneumonia were potentially unnecessary

Respiratory virus detection in the upper respiratory tract of asymptomatic, community‑dwelling older people

Background: The prevalence of virus positivity in the upper respiratory tract of asymptomatic community-dwelling older people remains elusive. Our objective was to investigate the prevalence of respiratory virus PCR positivity in asymptomatic community-dwelling older people using saliva samples and nasopharyngeal and oropharyngeal swabs.Methods: We analyzed 504 community-dwelling adults aged ≥ 65 years who were ambulatory and enrolled in a cross-sectional study conducted from February to December 2018 in Nagasaki city, Japan. Fourteen respiratory viruses were identified in saliva, nasopharyngeal and oropharyngeal samples using multiplex PCR assays.Results: The prevalences of PCR positivity for rhinovirus, influenza A, enterovirus and any respiratory virus were 12.9% (95% CI: 10.1–16.1%), 7.1% (95% CI: 5.1–9.8%), 6.9% (95% CI: 4.9–9.5%) and 25.2% (95% CI: 21.5–29.2%), respectively. Rhinovirus was detected in 21.5% of subjects, influenza A in 38.9% of subjects, enterovirus in 51.4% of subjects and any virus in 32.3% of subjects using only saliva sampling.Conclusions: The prevalences of several respiratory viruses were higher than the percentages reported previously in pharyngeal samples from younger adults. Saliva sampling is a potentially useful method for respiratory virus detection in asymptomatic populations

Clusters of Coronavirus Disease in Communities, Japan, January-April 2020

We analyzed 3, 184 cases of coronavirus disease in Japan and identified 61 case-clusters in healthcare and other care facilities, restaurants and bars, workplaces, and music events. We also identified 22 probable primary case-patients for the clusters; most were 20-39 years of age and presymptomatic or asymptomatic at virus transmission

Challenges in diagnosing scrub typhus among hospitalized patients with undifferentiated fever at a national tertiary hospital in northern Vietnam

BACKGROUND: Scrub typhus (ST) is a leading cause of non-malarial febrile illness in Southeast Asia, but evidence of its true disease burden is limited because of difficulties of making the clinical diagnosis and lack of adequate diagnostic tests. To describe the epidemiology and clinical characteristics of ST, we conducted an observational study using multiple diagnostic assays at a national tertiary hospital in Hanoi, Vietnam. METHODOLOGY/PRINCIPAL FINDINGS: We enrolled 1,127 patients hospitalized with documented fever between June 2012 and May 2013. Overall, 33 (2.9%) patients were diagnosed with ST by PCR and/or screening of ELISA for immunoglobulin M (IgM) with confirmatory tests: 14 (42.4%) were confirmed by indirect immunoperoxidase assay (IIP), and 19 (57.6%) were by IIP and PCR. Living by farming, conjunctival injection, eschar, aspartate aminotransferase elevation, and alanine aminotransferase elevation were significantly associated with ST cases (adjusted odds ratios (aORs): 2.8, 3.07, 48.8, 3.51, and 4.13, respectively), and having a comorbidity and neutrophilia were significantly less common in ST cases (aORs: 0.29 and 0.27, respectively). The majority of the ST cases were not clinically diagnosed with rickettsiosis (72.7%). Dominant IIP reactions against a single antigen were identified in 15 ST cases, whereas indistinguishably high reactions against multiple antigens were seen in 11 ST cases. The most frequently observed dominant IIP reaction was against Karp antigen (eight cases) followed by Gilliam (four cases). The highest diagnostic accuracy of IgM ELISA in acute samples was 78%. In a phylogenetic analysis of the 56-kDa type-specific antigen gene, the majority (14 cases) were located in the Karp-related branch followed by the Gilliam-related (two cases), Kato-related (two cases), and TA763-related clades (one case). CONCLUSIONS/SIGNIFICANCE: Both the clinical and laboratory diagnoses of ST remain challenging at a tertiary hospital. Implementation of both serological and nucleic acid amplification assays covering endemic O. tsutsugamushi strains is essential

Effectiveness of Messenger RNA Coronavirus Disease 2019 Vaccines Against Symptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infections During the Delta Variant Epidemic in Japan: Vaccine Effectiveness Real-time Surveillance for SARS-CoV-2 (VERSUS)

Background. Although high vaccine effectiveness of messenger RNA (mRNA) coronavirus disease 2019 (COVID-19) vaccines has been reported in studies in several countries, data are limited from Asian countries, especially against the Delta (B.1.617.2) variant.Methods. We conducted a multicenter test-negative case-control study in patients aged ≥16 years visiting hospitals or clinics with signs or symptoms consistent with COVID-19 from 1 July to 30 September 2021, when the Delta variant was dominant (≥90% of SARS-CoV-2 infections) nationwide in Japan. Vaccine effectiveness of BNT162b2 or mRNA-1273 against symptomatic SARS-CoV-2 infections was evaluated. Waning immunity among patients aged 16–64 years was also assessed.Results. We enrolled 1936 patients, including 396 test-positive cases and 1540 test-negative controls for SARS-CoV-2. The median age was 49 years, 53.4% were male, and 34.0% had underlying medical conditions. Full vaccination (receiving 2 doses ≥14 days before symptom onset) was received by 6.6% of cases and 38.8% of controls. Vaccine effectiveness of full vaccination against symptomatic SARS-CoV-2 infections was 88.7% (95% confidence interval [CI], 78.8%–93.9%) among patients aged 16–64 years and 90.3% (95% CI, 73.6%–96.4%) among patients aged ≥65 years. Among patients aged 16–64 years, vaccine effectiveness was 91.8% (95% CI, 80.3%–96.6%) within 1–3 months after full vaccination, and 86.4% (95% CI, 56.9%–95.7%) within 4–6 months.Conclusions. mRNA COVID-19 vaccines had high effectiveness against symptomatic SARS-CoV-2 infections in Japan during July–September 2021, when the Delta variant was dominant nationwide

Epidemiology of Coronavirus Disease Outbreak among Crewmembers on Cruise Ship, Nagasaki City, Japan, April 2020

In April 2020, a coronavirus disease (COVID-19) outbreak occurred on the cruise ship Costa Atlantica in Nagasaki, Japan. Our outbreak investigation included 623 multinational crewmembers onboard on April 20. Median age was 31 years; 84% were men. Each crewmember was isolated or quarantined in a single room inside the ship, and monitoring of health status was supported by a remote health monitoring system. Crewmembers with more severe illness were hospitalized. The investigation found that the outbreak started in late March and peaked in late April, resulting in 149 laboratory-confirmed and 107 probable cases of infection with severe acute respiratory syndrome coronavirus 2. Six case-patients were hospitalized for COVID-19 pneumonia, including 1 in severe condition and 2 who required oxygen administration, but no deaths occurred. Although the virus can spread rapidly on a cruise ship, we describe how prompt isolation and quarantine combined with a sensitive syndromic surveillance system can control a COVID-19 outbreak

Effectiveness of mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections during the SARS-CoV-2 Omicron BA.1 and BA.2 epidemic in Japan: vaccine effectiveness real-time surveillance for SARS-CoV-2 (VERSUS)

Background: Evaluating COVID-19 vaccine effectiveness (VE) domestically is crucial for assessing and determining national vaccination policy. This study aimed to evaluate VE of mRNA COVID-19 vaccines in Japan. Methods: We conducted a multicenter test-negative case-control study. The study comprised indivi-duals aged ≥16 visiting medical facilities with COVID-19-related signs or symptoms from 1 January to 26 June 2022, when Omicron BA.1 and BA.2 were dominant nationwide. We evaluated VE of primary and booster vaccination against symptomatic SARS-CoV-2 infections and relative VE of booster compared with primary.Results: We enrolled 7,931 episodes, including 3,055 test positive. The median age was 39, 48.0% were male, and 20.5% had underlying medical conditions. In individuals aged 16 to 64, VE of primary vaccination within 90 days was 35.6% (95% CI, 19.0–48.8%). After booster, VE increased to 68.7% (60.6–75.1%). In individuals aged ≥65, VE of primary and booster was 31.2% (−44.0–67.1%) and 76.5% (46.7–89.7%), respectively. Relative VE of booster compared with primary vaccination was 52.9% (41.0– 62.5%) in individuals aged 16 to 64 and 65.9% (35.7–81.9%) in individuals aged ≥65.Conclusions: During BA.1 and BA.2 epidemic in Japan, mRNA COVID-19 primary vaccination provided modest protection. Booster vaccination was necessary to protect against symptomatic infections

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 [...