Epidemiologic trends and distributions of imported infectious diseases among travelers to Japan before and during the COVID-19 pandemic, 2016 to 2021: a descriptive study

BACKGROUND: Little is known about the trends of imported infectious diseases among travelers to non-endemic countries during the COVID-19 pandemic. This article aimed to describe those among travelers to Japan. METHODS: This is a descriptive study based on national surveillance data. Imported infectious disease cases were defined as those with a reported overseas source of infection among 15 diseases pre-selected based on the probability and impact of importation. The number of notified cases from April 2016 to March 2021 were described by disease and time of diagnosis. The relative ratio and absolute difference in case counts-both by number and per arrival-were calculated by disease comparing those from the pandemic period (April 2020-March 2021) to the pre-pandemic period (April 2016-March 2020). RESULTS: A total of 3524 imported infectious disease cases were diagnosed during the study period, including 3439 cases before and 85 cases during the pandemic. The proportionate distribution of diseases changed but notification counts of all 15 diseases decreased during the pandemic. Accounting for arrivals, however, seven diseases showed a two-fold or greater increase, with a notable absolute increase per million arrivals for amebiasis (60.1; 95%CI, 41.5-78.7), malaria (21.7; 10.5-33.0), and typhoid fever (9.3; 1.9-16.8). CONCLUSION: The epidemiology of imported infectious diseases changed during the pandemic. While the number of imported infectious disease cases decreased, the number of cases per arrivals increased considerably both in relative and absolute terms for several diseases of public health and clinical importance

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Preparation for mass gathering events from the perspective of a non-host country: the experience of Japan during the 2018 PyeongChang Olympics and Paralympic Winter Games

The World Health Organization recommends that countries or organizations that host mass gatherings plan ahead and prepare for possible public health events to ensure a safe environment for local residents, participants and travellers.1 Public health events during mass gatherings can also affect non-host countries. There are numerous reports of the spread of infectious diseases by travellers returning from mass gatherings,2 which can potentially pose the risk of an outbreak of new infectious diseases to travellers’ home countries. With more frequent travel across borders, it is prudent that non-host countries prepare for mass gathering events

Dengue Sentinel Traveler Surveillance: Monthly and Yearly Notification Trends among Japanese Travelers, 2006–2014 - Fig 6

<p>Number of domestic dengue cases reported from (A) the Philippines and (B) Thailand, and the annual number of imported dengue cases per 100,000 travelers visiting each country, 2006–2014.</p

Distribution of reported imported dengue cases by sex and age, Japan, 2006–2014 (n = 1007).

<p>Distribution of reported imported dengue cases by sex and age, Japan, 2006–2014 (n = 1007).</p

Number of reported imported dengue cases aggregated over month by country visited, Japan, 2006–2014 (n = 1007).

<p>Number of reported imported dengue cases aggregated over month by country visited, Japan, 2006–2014 (n = 1007).</p

Number of reported imported dengue cases per 100,000 travelers aggregated over month by country visited, Japan, 2006–2014.

<p>For Indonesia, monthly data for Japanese travelers were only available for Bali province. Philippines data were restricted to those from 2006–2013 as monthly traveler data were not available for 2014. Monthly Japanese traveler data were not available for India.</p

Numbers of reported imported dengue cases, Japanese travelers, and reported dengue cases per 100,000 Japanese travelers by country visited and month, 2006–2014.

<p>Numbers of reported imported dengue cases, Japanese travelers, and reported dengue cases per 100,000 Japanese travelers by country visited and month, 2006–2014.</p

Number of reported imported dengue cases per 100,000 travelers by year and country visited, Japan, 2006–2014.

<p>Data for Japanese travelers visiting India and Indonesia were not available for 2014.</p