Reconstructing the population dynamics of foreign residents in Japan to estimate the prevalence of infection with Mycobacterium tuberculosis

Atypical clinical and radiological presentations of lumbar spinal tuberculosis mimicking a spinal tumor: A case report

INTRODUCTION

Tuberculosis (TB) is an important infectious disease worldwide. Classical spinal TB has specific radiological findings involving adjacent vertebral bodies with destruction of the intervertebral disc and involvement of paravertebral soft tissues with cold abscess formation. However, a few cases not exhibiting the radiological characteristics of TB spondylitis have been reported. We report a rare case of lumbar spinal TB with atypical clinical and radiological presentations that was difficult to differentiate from a malignant spinal tumor.

PATIENT CONCERNS

A 21-year-old man, who had immigrated to Japan from the Philippines 5 years ago, without a significant medical history, presented with back pain lasting 1 month and progression of gait disturbance 2 weeks prior to presentation.

DIAGNOSIS

Laboratory tests showed normal blood cell counts and normal value of C-reactive protein levels. Preoperative imaging studies indicated a possible spinal tumor. However, histopathologic findings of the epidural soft tissues at the first surgery led to the diagnosis of spinal mycobacterial infection. The diagnosis of spinal TB was confirmed by a positive culture of Mycobacterium tuberculosis obtained at the second surgery.

INTERVENTIONS

Given the progressive nature of neurologic deterioration, instead of needle biopsy, we proceeded with surgical intervention 8 days after admission; simultaneous neural decompression and open biopsy. Histological findings of the excised epidural soft tissues led to the diagnosis of spinal mycobacterial infection. We performed the second surgery involving additional resection of epidural soft tissues for further dural decompression and to obtain specimens for mycobacterial culture. Immediately after the second surgery, the patient commenced combination therapy with anti-tuberculous drugs.

OUTCOMES

The patient demonstrated significant recovery of motor function in the lower extremities, and was able to run at 2 months after the second surgery. The epidural granulomas completely disappeared on magnetic resonance imaging 3 months postoperatively.

CONCLUSION

Atypical clinical and radiological presentations of spinal TB present a challenge for appropriate diagnosis and early treatment. Even in developed countries where there are very few spinal TB patients, clinicians should be aware that spinal TB is an important differential diagnosis, especially in elderly patients or patients coming from countries with a middle-high prevalence of TB.

Surveillance and risk assessment of health screening for vaccine-preventable diseases among international students in Japan: A cross-sectional study in 2020

We conducted a cross-sectional study using a structured questionnaire in three major Japanese cities from August 03 to 24, 2020 to clarify the current situation of health checkups, including vaccine-preventable diseases (VPDs), among international students at Japanese universities (JUs) and Japanese language schools (JLSs). The total response rate was 36%: 69 JUs (31%) and 137 JLSs (39%). Over 90% of these institutions conducted chest X-ray screening for tuberculosis among their students, whereas only 24.6% of JUs and 15.3% of JLSs performed general blood tests for health screening. Only 14.5% and 2.2% of the JUs and JLSs, respectively, required the submission of vaccination or antibody certificates for admission. The difficulties in requesting vaccination certificates from international students are due to poor legal requirements and concerns about rising costs for schools. From 2017 to 2019, 183 international students, principally from East Asia and Southeast Asia, were infected with VPDs, particularly tuberculosis (99 cases) and varicella (71 cases). Whereas the majority of Japanese educational institutions screen international students for tuberculosis (TB) at admission, only a few institutions request proof of antibody testing relating to other VPDs or of vaccination. These findings will help formulate guidelines for checkups related to vaccination for international students required to protect the educational institutions in Japan from the spread of VPDs. In addition, providing multifaceted social support, including financial compensation for institutions and enhanced international students' health issues, would be helpful.

The burden and predictors of latent tuberculosis infection among immigrants in South Korea: a retrospective cross-sectional study

BACKGROUND

Approximately one-fourth of the global population is latently infected with Mycobacterium tuberculosis. An understanding of the burden of latent tuberculosis infection (LTBI) among immigrants compared with the general Korean population should be the first step in identifying priority groups for LTBI diagnosis and treatment. The study aimed to compute the age-standardized LTBI prevalence and predictors among immigrants with LTBI in South Korea.

METHODS

In 2018, the Korea Disease Control and Prevention Agency implemented a pilot LTBI screening project for immigrants using a chest radiography and the QuantiFERON Gold In-Tube assay. A standardized prevalence ratio (SPR) was computed to compare the LTBI burden in immigrants and the general Korean population.

RESULTS

During the duration of the project, a total of 8108 immigrants (5134 males and 2974 females) underwent LTBI screening. The SPR of 1.547 (95% confidence interval [CI] 1.468-1.629) in males and 1.261 (95% CI 1.177-1.349) in females were both higher than the Korean reference population. Furthermore, among the immigrants, those aged < 40 years and Korean diaspora visa holders had a higher SPR.

CONCLUSION

This study found a higher LTBI prevalence among immigrant population in South Korea compared to that in the general Korean population, and the SPR was higher among those aged < 40 years and the Korean diaspora. The findings can be used as baseline evidence for including immigrants in South Korea in the at-risk group with a priority need for LTBI screening and treatment.

Phenotypic and genotypic features of the Mycobacterium tuberculosis lineage 1 subgroup in central Vietnam

Mycobacterium tuberculosis (Mtb) has different features depending on different geographic areas. We collected Mtb strains from patients with smear-positive pulmonary tuberculosis in Da Nang, central Vietnam. Using a whole genome sequencing platform, including genome assembly complemented by long-read-sequencing data, genomic characteristics were studied. Of 181 Mtb isolates, predominant Vietnamese EAI4_VNM and EAI4-like spoligotypes (31.5%), ZERO strains (5.0%), and part of EAI5 (11.1%) were included in a lineage-1 (L1) sublineage, i.e., L1.1.1.1. These strains were found less often in younger people, and they genetically clustered less frequently than other modern strains. Patients infected with ZERO strains demonstrated less lung infiltration. A region in RD2bcg spanning six loci, i.e., PE_PGRS35, cfp21, Rv1985c, Rv1986, Rv1987, and erm(37), was deleted in EAI4_VNM, EAI4-like, and ZERO strains, whereas another 118 bp deletion in furA was specific only to ZERO strains. L1.1.1.1-sublineage-specific deletions in PE_PGRS4 and PE_PGRS22 were also identified. RD900, seen in ancestral lineages, was present in majority of the L1 members. All strains without IS6110 (5.0%) had the ZERO spoligo-pattern. Distinctive features of the ancestral L1 strains provide a basis for investigation of the modern versus ancestral Mtb lineages and allow consideration of countermeasures against this heterogeneous pathogen.

Measles and Rubella during COVID-19 Pandemic: Future Challenges in Japan

The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted essential health services. Simultaneously, it has created opportunities for citizens to raise awareness of personal hygiene, mask wearing, and other preventive measures. This brief report aims to clarify the epidemiological trends of measles and rubella in Japan and to explore future challenges for controlling these diseases during and after the COVID-19 pandemic. Although Japan eliminated measles in 2015, the number of measles patients has gradually increased since then, and reached 744 in 2019. In the 2010s, Japan experienced two large rubella epidemics, and the majority of the patients were reported in Tokyo and other metropolitan areas. While the transmission of measles and rubella seems to be suppressed during the COVID-19 pandemic, closing the gap in routine childhood vaccination will be challenging in any country. Moreover, supplementary immunization campaigns for adults have also been disrupted, and they must be invigorated. While the pandemic has a devastating effect on a global scale, it should be utilized as a good opportunity to regain faith in vaccines, implement an evidence-based vaccination policy, and strengthen international cooperation.

A structured Markov chain model to investigate the effects of pre-exposure vaccines in tuberculosis control

In this paper, the interest is in a structured Markov chain model to describe the transmission dynamics of tuberculosis (TB) in the setting of small communities of hosts sharing confined spaces, and to explore the potential impact of new pre-exposure vaccines on reducing the number of new TB cases during an outbreak of the disease. The model under consideration incorporates endogenous reactivation of latent tubercle bacilli, exogenous reinfection of latently infected TB hosts, loss of effectiveness of the vaccine protection, and death of hosts due to tubercle bacilli and from causes beyond TB. Various probabilistic measures are defined and analytically studied to describe extreme values and the number of vaccinations during an outbreak, and a random version of the basic reproduction number is used to measure the transmission potential during the initial phase of the epidemic. Our numerical experiments allow us to compare different pre-exposure vaccines versus the level of coverage in terms of these probabilistic measures.