Outbreak Area Research Articles

Spatiotemporal characteristics analysis and potential distribution prediction of peste des petits ruminants (PPR) in China from 2007-2018.

Peste des petits ruminants (PPR) is a highly infectious disease that mainly infects small ruminants. To date, PPR has been confirmed in more than 70 countries. In China, PPR has occurred in more than 20 provinces and cities. In this study, based on geographic information system (GIS), spatial analysis was used to examine the occurrence of PPR in China from 2007 to 2018. The results showed that PPR first occurred in Tibet and gradually spread to other provinces. The outbreaks of PPR were concentrated in 2014, 2015 and 2018. Combining climate factors with the maximum entropy (MaxEnt), the results also suggested that the potential risk areas of PPR outbreaks in China were mainly Jiangsu, Yunnan and Anhui in Southeast China. Finally, a phylogenetic tree was used to analyse the evolutionary relationship between the peste des petits ruminants virus (PPRV) in China and the global ones, and it was found that the one in China had a close genetic relationship with the one in Mongolia, India and Bangladesh. Understanding and forecasting the distribution of PPR in China will help policymakers develop targeted monitoring plans. Likewise, analysing the global PPRV epidemic trends will play an important role in the elimination and prevention of PPR.

Biochemical and molecular identification of Gram-positive isolates with β-hemolysis activity isolated from the nasal swab of pigs during the human meningitis outbreak in Badung Regency, Bali-Indonesia.

Background and Aim:The nasal cavity of a pig serves as an entry point and a habitat for the colonization of commensal microbes and pathogenic bacteria. Based on biochemical and serological tests, Streptococcus b-hemolytic Group C was identified as the Gram-positive bacteria, which resulted in the 1994 outbreak and death of thousands of pigs in Bali. Furthermore, this agent is zoonotic and frequently results in the development of meningitis lesions in the infected pig. Recently, a meningitis outbreak in humans was also reported after the consumption of pig-derived foods at Sibang Kaja, Badung-Bali. This study aimed to identify and characterize Gram-positive β-hemolytic organisms collected from nasal swab of pigs from the outbreak area, as well as to compare API Kit and 16S rRNA gene analysis methods.Materials and Methods:This study commenced with the cultivation of two isolates, Punggul Swab Nasal (PSN) 2 and PSN 19, which were characterized by β-hemolysis activity. These samples were then conventionally and molecularly identified using Kit API 20 Strep and 16S ribosomal RNA (rRNA) gene primers, respectively.Results:Using the Kit API 20 Strep, both isolates were identified as Enterococcus faecium, which was previously classified as Group D Streptococci. Based on the 16S rRNA gene sequencing, PSN 2 and PSN 19 were molecularly confirmed to have 99 and 98.1% similarities with E. faecium (NR042054), respectively. Furthermore, both isolates share the same clade in the phylogenetic tree analysis.Conclusion:Using Kit API 20 Strep and 16S rRNA gene analysis, the PSN 2 and PSN 9 Gram-positive isolates with β-hemolysis activity from pig nasal swabs were identified as E. faecium.

Rabies in Poland in 2021

Until 2020, the rabies epizootic situation in Poland was favourable. This was interrupted, however, by a rabies outbreak in Mazowieckie voivodeship, which caused a drastic increase in rabies cases among animals, mainly red foxes. Here, we present data on the species and geographical distribution of rabies cases in domestic and wild animals, including bats, in Poland in 2021. In order to limit the transmission of the rabies virus, the Veterinary Inspectorate has introduced appropriate measures, including emergency vaccination and additional oral rabies vaccination (ORV) campaigns for foxes. Nevertheless, strict and comprehensive ORV and rabies surveillance are required to eliminate rabies from the area of rabies outbreak in 2021.

Quantifying and predicting population connectivity of an outbreaking forest insect pest

ContextDispersal has a key role in the population dynamics of outbreaking species such as the spruce budworm (Choristoneura fumiferana) as it can synchronize the demography of distant populations and favor the transition from endemic to epidemic states. However, we know very little about how landscape structure influences dispersal in such systems while such knowledge is essential for better forecasting of spatially synchronous population dynamics and to guide management strategies.ObjectivesWe aimed to characterize the spatial environmental determinants of spruce budworm dispersal to determine how these features affect outbreak spread in Quebec (Canada). We then apply our findings to predict expected future landscape connectivity and explore its potential consequences on future outbreaks.MethodsWe used a machine-learning landscape genetics approach on 447 larvae covering most of the outbreak area and genotyped at 3562 SNP loci to identify the main variables affecting connectivity.ResultsWe found that the connectivity between outbreak populations was driven by the combination of precipitation and host cover. Our forecasting suggests that between the current and next outbreaks, connectivity may increase between Ontario and Quebec, and might decrease in the eastern part, which could have the effect of limiting outbreak spread from Ontario and Quebec to the eastern provinces.ConclusionsAlthough we did not identify any discrete barriers, low connectivity areas might constrain dispersal in the current and future outbreaks and should in turn, be intensively monitored. However, continued sampling as the outbreak progresses is needed to confirm the temporal stability of the observed patterns.

Outbreak and Insecticide Susceptibility of Pod Feeding-larvae on Cocoa in Ghana

Cocoa is an important foreign exchange earner and a major source of income for several households in Ghana. In 2018, a larval outbreak on cocoa pods was reported in Ghana. Although the origin is unknown, it was perceived to be a secondary pest outbreak. In this study, a survey was conducted in the outbreak areas to identify and determine the occurrence of the pest and its susceptibility to a commonly used insecticide. Field and laboratory studies were conducted to identify the pest, determine the level of infestation, insecticide susceptibility, and field management. The outbreak was mainly caused by larvae of Anomis leona (~96% infestation of cocoa trees in some communities) with extensive feeding damage (chewing channels/tunnels) on the pericarp of pods. Field populations of A. leona larvae from districts in the Central region subjected to bifenthrin were susceptible at the recommended field rate (0.0245%) for mirids after 48 h of exposure under laboratory conditions. The insecticide induced a median lethal concentration (LC50) of ≤0.0061% and ≤0.0018% on A. leona larvae from Jukwa and Twifo Praso in the Central region at 24 and 48 h of exposure, respectively. Field application of bifenthrin was able to suppress infestation. The findings show that Anomis larvae were responsible for the outbreak, inducing extensive damage on pods. Bifenthrin was toxic to the larvae and could be used to manage them on the field. The outbreak indicates the need to develop an integrated management and monitoring strategy for cocoa pests to minimize future outbreaks.

Stress-related to COVID-19, anxiety, and protective factors among middle-aged and older adults in the largest outbreak areas in South Korea

Objectives The present study examined the impact of psychological stress related to COVID-19 on anxiety as well as protective factors against these negative psychological consequences among middle-aged and older adults in the largest outbreak areas in South Korea. Method Participants included 667 middle-aged and older adults (ages 40 to 76) living in the largest outbreak areas at the time of the survey based on the number of confirmed COVID-19 cases in South Korea. Path analysis was conducted. Results Stress related to COVID-19 and loneliness were positively associated with anxiety. However, family cohesion, resilience, health, and being married were negatively associated with anxiety. Also, family cohesion, resilience, income, and being married were negatively associated with loneliness among middle-aged and older adults in the largest outbreak areas in South Korea. Conclusion As postulated by the Stress Process Model, stress related to COVID-19 may have increased loneliness and anxiety among middle-aged and older adults in the largest outbreak areas in South Korea; however, resilience and family cohesion reduced these negative consequences both directly and indirectly. Findings are discussed and implications are addressed.

Acceptance of COVID-19 vaccines among college students: a study of the attitudes, knowledge, and willingness of students to vaccinate

ABSTRACT Universities are considered high risk areas for COVID-19 outbreaks given the crowded environment of campuses with high mobility and limited space. As such, vaccination is considered an essential intervention that could greatly reduce the incidence and spread of this deadly infectious disease. However, the willingness of college students to receive the COVID-19 vaccine varies significantly. Therefore, a study on the acceptance of COVID-19 vaccines in college students that explores the attitudes, knowledge, willingness, and key factors influencing vaccination acceptance is of great significance to improve vaccine coverage and control the pandemic. A cross-sectional survey was conducted on students from three universities in China. Descriptive statistics, independent sample t tests/one-way ANOVA (normal distribution), Mann-Whitney U tests/Kruskal-Wallis H tests (skewness distribution) and multivariate linear regression were performed. As a result, a total of 3,256 students participated in the survey. Students’ willingness to receive the COVID-19 vaccine was high (86%), and they had good knowledge of the vaccine (77.9%). However, they had a low-risk perception of COVID-19 and less positive attitudes toward vaccination (69.8%). The main influencing factors were sex, age, specialty, grades, living environment, spending level, traveling to risk areas, and family members’ vaccination experiences. We believed that to increase vaccination coverage among college students, more attention should be paid for students majoring in Science and Engineering, male students, those in the lower age group, students with low or very high economic levels, living in remote or rural areas, and family members having not received the COVID-19 vaccine.

Impact of the COVID-19 Pandemic on Emergency Department Workload and Emergency Care Workers' Psychosocial Stress in the Outbreak Area.

Background and Objectives: Due to the unexpected spread of coronavirus disease 2019 (COVID-19), there was a serious crisis of emergency medical system collapse. Healthcare workers working in the emergency department were faced with psychosocial stress and workload changes. Materials and Methods: This was a cross-sectional survey of healthcare workers in the emergency department in Daegu and Gyeongbuk, Korea, from November 16 to 25, 2020. In the survey, we assessed the general characteristics of the respondents; changes in the working conditions before and after the COVID-19 pandemic; and resulting post-traumatic stress disorder, depression and anxiety statuses using 49 questions. Results: A total of 529 responses were collected, and 520 responses were included for the final analyses. Changes in working conditions and other factors due to COVID-19 varied by emergency department level, region and disease group. Working hours, intensity, role changes, depression and anxiety scores were higher in the higher level emergency department. Isolation ward insufficiency and the risk of infection felt by healthcare workers tended to increase in the lower level emergency department. Treatment and transfer delay were higher in the fever and respiratory disease groups (M = 3.58, SD = 1.18; M = 4.08, SD = 0.95), respectively. In all the disease groups, both treatment and transfer were delayed more in Gyeongbuk than in Daegu. Conclusions: Different goals should be pursued by the levels and region of the emergency department to overcome the effects of the COVID-19 pandemic and promote optimal care.

In vivo and in silico Virulence Analysis of Leptospira Species Isolated From Environments and Rodents in Leptospirosis Outbreak Areas in Malaysia.

The zoonotic disease leptospirosis is caused by pathogenic species of the genus Leptospira. With the advancement of studies in leptospirosis, several new species are being reported. It has always been a query, whether Leptospira species, serovars, and strains isolated from different geographical locations contribute to the difference in the disease presentations and severity. In an epidemiological surveillance study performed in Malaysia, we isolated seven novel intermediate and saprophytic species (Leptospira semungkisensis, Leptospira fletcheri, Leptospira langatensis, Leptospira selangorensis, Leptospira jelokensis, Leptospira perdikensis, Leptospira congkakensis) from environments and three pathogenic species from rodents (Leptospira borgpetersenii strain HP364, Leptospira weilii strain SC295, Leptospira interrogans strain HP358) trapped in human leptospirosis outbreak premises. To evaluate the pathogenic potential of these isolates, we performed an in vivo and in silico virulence analysis. Environmental isolates and strain HP364 did not induce any clinical manifestations in hamsters. Strain SC295 caused inactivity and weight loss with histopathological changes in kidneys, however, all hamsters survived until the end of the experiment. Strain HP358 showed a high virulent phenotype as all infected hamsters died or were moribund within 7 days postinfection. Lungs, liver, and kidneys showed pathological changes with hemorrhage as the main presentation. In silico analysis elucidated the genome size of strain HP358 to be larger than strains HP364 and SC295 and containing virulence genes reported in Leptospira species and a high number of specific putative virulence factors. In conclusion, L. interrogans strain HP358 was highly pathogenic with fatal outcome. The constituent of Leptospira genomes may determine the level of disease severity and that needs further investigations.

Variants of ctxB alleles of Vibrio cholerae O1 caused sequential cholera outbreaks in the tribal areas of Odisha, India.

Cholera localized outbreaks/epidemics accounting for high morbidity and mortality have been reported in different years both from the coastal and tribal districts of Odisha. In the present study, the emergence and spread of two sequential cholera outbreaks reported in July to October 2012 from Rayagada and Kalahandi districts of Odisha was investigated. Environmental water samples from different sources and rectal swabs from diarrhoea patients were analysed for identification, antibiogram profiles and molecular studies using DMAMA-PCR assays. The pulsed field gel electrophoresis (PFGE) was done on some selected Vibrio cholerae O1 strains isolated from these cholera outbreak areas. Results showed 42% of rectal swabs and 2.3% of water samples collected from both the districts were positive for Vibrio cholerae O1 Ogawa biotype El Tor carrying both ctxB1 and ctxB7 genotypes. The common resistance profile of V. cholerae O1 strains was ampicillin, nalidixic acid, furazolidone and co-trimoxazole. The PFGE analysis on selected V. cholerae O1 strains of ctxB1 and ctxB7 genotypes showed three pulsotypes with 96% similarity matrix exhibiting the relationship with their respective water sources. Hence, continuous surveillance is highly essential to monitor the antibiogram profile and changing pattern of ctxB genotypes of V. cholerae O1 in this region.

Evidence that Xylella fastidiosa is the Causal Agent of Almond Leaf Scorch Disease in Alicante, Mainland Spain (Iberian Peninsula).

In 2017, Xylella fastidiosa, a quarantine plant-pathogenic bacterium in Europe, was detected in almond trees associated with leaf scorch symptoms in Alicante, a Mediterranean area in southeastern mainland Spain. The bacterium was detected by serological and molecular techniques, isolated in axenic culture from diseased almond trees, and identified as X. fastidiosa subsp. multiplex sequence type (ST) 6. Inoculation experiments on almond plants in greenhouse trials with a characterized strain of X. fastidiosa subsp. multiplex ST6 isolated in the outbreak area have proved that it was able to multiply and systemically colonize inoculated plants. Disease symptoms characteristic of leaf scorch like those observed in the field were observed in the inoculated almond trees after 1 year. Furthermore, the pathogen was reisolated and identified by molecular tests. With the fulfillment of Koch's postulates, we have demonstrated that X. fastidiosa is the causal agent of the almond leaf scorch disease in the Alicante outbreak.

Bioexploration and Phylogenetic Placement of Entomopathogenic Fungi of the Genus Beauveria in Soils of Lebanon Cedar Forests.

The cedar forests of Lebanon have been threatened by the outbreak caused by climate change of a web-spinning sawfly, Cephalcia tannourinensis (Hymenoptera: Pamphiliidae), which negatively impacted the survival of one of the oldest tree species on earth. In this study, we investigated the occurrence of naturally soil-inhabiting entomopathogenic fungi for their role in containing the massive outbreak of this insect. We used a combination of fungal bioexploration methods, including insect bait and selective media. Morphological features and multilocus phylogeny—based on Sanger sequencing of the transcripts encoding the translation elongation factor 1-alpha (TEF-α), RNA polymerase II second largest subunit (RBP2), and the nuclear intergenic region (Bloc) were used for species identification. The occurrence rate of entomopathogenic fungi (EPF) varied with location, soil structure, forest structure, and isolation method. From 15 soil samples positive for fungal occurrence, a total of 249 isolates was obtained from all locations using different isolation methods. The phylogenetic analysis confirmed the existence of two novel indigenous species: Beauveria tannourinensis sp. nov. and Beauveria ehdenensis sp. nov. In conclusion, the present survey was successful (1) in optimizing the isolation methods for EPF, (2) investigating the natural occurrence of Beauveria spp. in outbreak areas of C. tannourinensis, and (3) in characterizing the presence of new Beauveria species in Lebanese cedar forest soil.

Discovering source areas of disease outbreaks based on ring-shaped hotspot detection in road network space

ABSTRACT The accurate discovery of disease-outbreak source areas plays a critical role in the effective containment of epidemics at an early stage. Existing relevant methods are mostly implemented by tracing the source of disease outbreaks directly from the distribution of confirmed cases in the Euclidean space. In reality, in most respiratory infectious diseases, crowd gathering caused by resident trips significantly increases the risk of exposure to potentially infected persons, making it the driving force behind the outbreak of the disease. In light of this, this study proposes a network-constrained ring-shaped hotspot detection method based on the classical spatial scan statistic model. This new method can be used to determine the sizes of the scanning window in an adaptive manner by using the information of the trip distance distributions. Considering the centered traffic analysis zone in each hotspot as a candidate outbreak source area, a multi-factor coupling model was designed by characterizing both the areal vibrancy and resident trip distributions to further identify the potential disease-outbreak source areas. A case study on the outbreaks of COVID-19 in Wenzhou, China, was carried out to evaluate the practicability and effectiveness of the proposed method. The comparison results demonstrate the effectiveness of the proposed method for detecting areas and sources of outbreaks.

Detection and Response to an HIV Cluster: People Living Homeless and Using Drugs in Seattle, Washington

The HIV epidemic in King County, Washington has traditionally been highly concentrated among men who have sex with men, and incidence has gradually declined over 2 decades. In 2018, King County experienced a geographically concentrated outbreak of HIV among heterosexual people who inject drugs. Data sources to describe the 2018 outbreak and King County's response were partner services interview data, HIV case reports, syringe service program client surveys, hospital data, and data from a rapid needs assessment of homeless individuals and people who inject drugs. In 2020, the authors examined the impact of delays in molecular sequence analyses and cluster member size thresholds, for identifying genetically similar clusters, on the timing of outbreak identification. In 2018, the health department identified a North Seattle cluster, growing to 30 people with related HIV infections diagnosed in 2008-2019. In total, 70% of cluster members were female, 77% were people who inject drugs, 87% were homeless, and 27% reported exchanging sex. Intervention activities included a rapid needs assessment, 2,485 HIV screening tests in a jail and other outreach settings, provision of 87,488 clean syringes in the outbreak area, and public communications. A lower cluster size threshold and more rapid receipt and analyses of data would have identified this outbreak 4-16 months earlier. This outbreak shows the vulnerability of people who inject drugs to HIV infection, even in areas with robust syringe service programs and declining HIV epidemics. Although molecular HIV surveillance did not identify this outbreak, it may have done so with a lower threshold for defining clusters and more rapid receipt and analyses of HIV genetic sequences.

Genetic characterization of chikungunya virus isolates from Aedes aegypti mosquitoes collected during a recent outbreak in Bangkok, Thailand.

Chikungunya virus (CHIKV) is a mosquito-borne emerging pathogen that is transmitted to humans through the bite of female Aedes mosquitoes. CHIKV infection has become a major public health concern worldwide, as it has a significant impact on the healthcare system. Since 2004, the virus has emerged in Africa and subsequently spread to countries located near the Indian Ocean, including India, and to Europe, the Americas, and Asia. In Thailand, a large CHIKV outbreak occurred during 2008-2009 and was caused by a virus originating from the east/central/south African (ECSA) CHIKV genotype. Since then, the ECSA genotype of CHIKV has continued to circulate and has caused sporadic cases in different areas in Thailand. Approximately 20,000 reported cases have been confirmed by the Bureau of Epidemiology, Ministry of Public Health, Thailand, from January 1, 2018 to July 31, 2020. However, the causes of this CHIKV re-emergence remain unclear. To obtain a better understanding of CHIKV circulation during the recent outbreak in Bangkok, Thailand, complete genome analysis of CHIKV isolates from field-caught mosquitoes collected in outbreak areas was performed. A total of 28 Ae. aegypti samples (21 females and 7 males) were collected, and individual mosquitoes were used for CHIKV detection and isolation. Eleven of 28 (39.29%) female and three of 28 (10.71%) male mosquitoes were positive for CHIKV by E1 nested RT-PCR. Four CHIKV isolates were successfully isolated from four female Ae. aegypti mosquitoes. Based on complete genome analysis, several amino acid substitutions were identified in the protein coding region. The E1:K211E and E2:V264A mutations in the background of the E1:226A mutation were observed in all four CHIKV isolates. An important observation was the presence of one amino acid substitution, leading to an E1:K245R change. This mutation was found in all four CHIKV isolates from mosquitoes in this study and in Thai patients described previously. Additionally, phylogenetic analysis indicated that the four CHIKV isolates belonged to the Indian Ocean clade of the ECSA genotype. The results obtained in this study provide detailed information on the molecular characteristics and evolution of currently circulating CHIKV strains in Thailand, which are useful for developing prevention and control strategies.

The value of weather and climate information to the Tanzanian disaster risk reduction sector using non-monetary approaches

AbstractThis paper investigates the value of weather and climate information at different timescales for decision making in the Tanzanian disaster risk reduction sector using non-monetary approaches. Interviews and surveys were conducted with institutions responsible for disaster management at national, regional and district level. A range of values were identified including: 1) making informed decisions for disaster preparedness, response, recovery and restoration related activities; 2) tailoring of directives and actions based on sectoral impacts; 3) identification of hotspot areas for diseases outbreaks and surplus food production. However, while, a number of guidelines, policies, acts and regulations for disaster risk reduction exist it is not clear how well they promote the use of weather and climate information across climate sensitive sectors. Nonetheless, we find that well-structured disaster risk reduction coordination across sectors and institutions from the national to district level exists, although there is a need for further development of integrated Early Warning Systems, and a common platform to evaluate effectiveness and usefulness of weather warnings and advisories. Key challenges to address in increasing the uptake of weather warnings and advisories include language barriers, limited dissemination to rural areas, and limited awareness of forecasts. Based on the findings of this study, we recommend further quantitative evaluation of the skill of the severe weather warnings issued by the Tanzania Meteorological Authority, and an assessment of how decisions and actions are made by recipients of the warnings in the disaster risk reduction sector at different stages in the warning, response and recovery process.

Comparison of Different Waves during the COVID-19 Pandemic: Retrospective Descriptive Study in Thailand.

Background Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus. An outbreak is called an epidemic when there is a sudden increase in cases. Many countries have experienced a two-wave pattern in the reported cases of COVID-19. The spread of COVID-19 in Thailand was a cluster event distributed over multiple locations. This study aims to compare the characteristics of different waves during the COVID-19 pandemic in Thailand. Methods A retrospective cohort study was conducted from January 2020 to May 2021 (17 months) to determine the number of COVID-19 screenings and confirmed cases and deaths as well as sociodemographic characteristics such as gender, age, nationality, and source population at risk factors. The categorical data were compared using a chi-square test. Results Three waves of the COVID-19 pandemic occurred within 17 months in Thailand, and the number of cases increased by over 100,000 due to source population at risk factors such as close contact with a previously confirmed patient, community risk, cluster communities, and active and community surveillance. The chi-square test revealed significant differences between the three waves (p < 0.01). Conclusion Significant differences between pandemic phases or waves may be due to weak social distancing policies and the lack of public health interventions. A COVID-19 vaccination plan is needed for people at risk of suffering severe symptoms and the general population in outbreak areas to increase immunity.

Morphological, biological, and genomic characterization of a newly isolated lytic phage Sfk20 infecting Shigella flexneri, Shigella sonnei, and Shigella dysenteriae1

Shigellosis, caused by Shigella bacterial spp., is one of the leading causes of diarrheal morbidity and mortality. An increasing prevalence of multidrug-resistant Shigella species has revived the importance of bacteriophages as an alternative therapy to antibiotics. In this study, a novel bacteriophage, Sfk20, has been isolated from water bodies of a diarrheal outbreak area in Kolkata (India) with lytic activity against many Shigella spp. Phage Sfk20 showed a latent period of 20 min and a large burst size of 123 pfu per infected cell in a one-step growth analysis. Phage-host interaction and lytic activity confirmed by phage attachment, intracellular phage development, and bacterial cell burst using ultrathin sectioning and TEM analysis. The genomic analysis revealed that the double-stranded DNA genome of Sfk20 contains 164,878 bp with 35.62% G + C content and 241 ORFs. Results suggested phage Sfk20 to include as a member of the T4 myoviridae bacteriophage group. Phage Sfk20 has shown anti-biofilm potential against Shigella species. The results of this study imply that Sfk20 has good possibilities to be used as a biocontrol agent.

Delays in the diagnosis and treatment of tuberculosis during the COVID-19 outbreak in the Republic of Korea in 2020.

ObjectivesWe investigated the impact of the coronavirus disease 2019 (COVID-19) pandemic on tuberculosis (TB) "diagnosis and" management in the Republic of Korea (ROK).Methods This retrospective cross-sectional study used nationwide ROK TB notification data (98,346 cases) from 2017 to 2020. The median time from the onset of TB symptoms to treatment initiation and the compliance rates with the required timing for notification and individual case investigations were measured and compared across periods and regions affected by the COVID-19 epidemic.Results TB diagnosis during the COVID-19 pandemic was delayed. The median time to TB treatment initiation (25 days) in 2020 increased by 3 days compared to that of the previous 3 years (22 days) (p<0.0001). In the outbreak in Seoul, Incheon, and Gyeonggi province during August, the time to TB diagnosis was 4 days longer than in the previous 3 years (p=0.0303). In the outbreak in Daegu and Gyeongbuk province from February to March 2020, the compliance rate with the required timing for individual case investigations was 2.2%p lower than in other areas in 2020 (p=0.0148). For public health centers, the rate was 13%p lower than in other areas (80.3% vs. 93.3%, p=0.0003).Conclusion TB diagnoses during the COVID-19 pandemic in the ROK were delayed nationwide, especially for patients notified by public-private mix TB control hospitals. TB individual case investigations were delayed in regional COVID-19 outbreak areas (Daegu and Gyeongbuk province), especially in public health centers. Developing strategies to address this issue will be helpful for sustainable TB management during future outbreaks.

Internal migration networks and mortality in home communities: Evidence from Italy during the Covid-19 pandemic

Do internal migration networks benefit or harm their home communities in case of a communicable disease? Looking at the spread of Covid in Italy and using pre-determined province-to-province migration, excess mortality and mobile phone tracking data, we document that provinces with a greater share of migrants in outbreak areas show greater compliance with self-isolation measures (information mechanism), but also a greater population inflow from outbreak areas (carrier mechanism). For a subset of localities, the net effect on mortality is negative. However, for the average locality, the effect is positive and large, suggesting that the role of migrants as information providers is trumped by their role as virus carriers. The effect is quantitatively important and could be incorporated in epidemiological models forecasting the spread of communicable diseases.