Effects of non-pharmaceutical interventions on COVID-19 transmission: rapid review of evidence from Italy, the United States, the United Kingdom, and China.

Background: Prior to the development of COVID-19 vaccines, policymakers instituted various non-pharmaceutical interventions (NPIs) to limit transmission. Prior studies have attempted to examine the extent to which these NPIs achieved their goals of containment, suppression, or mitigation of disease transmission. Existing evidence syntheses have found that numerous factors limit comparability across studies, and the evidence on NPI effectiveness during COVID-19 pandemic remains sparse and inconsistent. This study documents the magnitude and variation in NPI effectiveness in reducing COVID-19 transmission (i.e., reduction in effective reproduction rate [Reff] and daily contact rate) in Italy, the United States, the United Kingdom, and China. Methods: Our rapid review and narrative synthesis of existing research identified 126 studies meeting our screening criteria. We selected four contexts with >5 articles to facilitate a meaningful synthesis. This step yielded an analytic sample of 61 articles that used data from China, Italy, the United Kingdom, and the United States. Results: We found wide variation and substantial uncertainty around the effectiveness of NPIs at reducing disease transmission. Studies of a single intervention or NPIs that are the least stringent had estimated Reff reductions in the 10-50% range; those that examined so-called "lockdowns" were associated with greater Reff reductions that ranged from 40 to 90%, with many in the 70-80% range. While many studies reported on multiple NPIs, only six of the 61 studies explicitly used the framing of "stringency" or "mild versus strict" or "tiers" of NPIs, concepts that are highly relevant for decisionmakers. Conclusion: Existing evidence suggests that NPIs reduce COVID-19 transmission by 40 to 90 percent. This paper documents the extent of the variation in NPI effectiveness estimates and highlights challenges presented by a lack of standardization in modeling approaches. Further research on NPI effectiveness at different stringency levels is needed to inform policy responses to future pandemics.

Norovirus outbreaks due to contaminated drinking water and probable person-to-person transmission, Kerala, India, 2021.

BACKGROUND: In July 2021, the Alappuzha district in Kerala, India, reported an unexpected number of acute gastroenteritis (772) cases (Outbreak A). On October 10, 2021, a university in Wayanad, Kerala, reported 25 acute gastroenteritis cases (Outbreak B). We described both the outbreaks and determined the agent, source and risk factors. METHODS: We defined a suspected case as the occurrence of vomiting or at least three episodes of loose stools within 24 h and a confirmed case as those with stool samples/rectal swabs positive for norovirus. We did a matched case-control study in Outbreak A and a retrospective cohort study in Outbreak B. We calculated the adjusted odds ratio (aOR) in outbreak A, relative risk (aRR) in outbreak B and population attributable fraction (PAF). We tested stool and water samples for bacteria and viruses. RESULTS: We identified Group II norovirus in stool samples in both outbreaks and 4/5 water samples in Outbreak A. Suspected norovirus infection was associated with drinking inadequately boiled water from the municipal water supply in outbreak A [aOR: 4.5; 95 % C.I: 1.2-15.8; PAF: 0.23] and well water in hostels in outbreak B [aRR: 2.2; 95 % C.I: 1.2-3.9; PAF: 0.15]. In Outbreak A, groundwater from tube wells was mixed in the municipal water supply overhead tanks without chlorination. CONCLUSION: The gastroenteritis outbreaks were caused by Group II norovirus due to the consumption of inadequately boiled contaminated groundwater (outbreak A) and well water (outbreak B). We recommended superchlorination of overhead tanks and wells and boiled water for drinking.

Murine typhus: an underappreciated influence on human disease transmission dynamics.

Murine typhus, a vector-borne illness transmitted by fleas and caused by Rickettsia typhi, presents significant public health challenges globally. Despite its impact, it often remains underrecognized in health systems. This disease is characterized by non-specific symptoms such as fever, rash, and severe complications in cases involving neurological or multi-organ involvement. The complexity of its clinical presentation frequently leads to misdiagnosis and underreporting, obscuring true transmission dynamics and impeding effective management. Highlighting the need for enhanced diagnostic methods, targeted public health interventions, and increased awareness, this review calls for a strategic focus to better understand and mitigate the influence of murine typhus on global health.

Mathematical modeling of infectious diseases and the impact of vaccination strategies.

Mathematical modeling plays a crucial role in understanding and combating infectious diseases, offering predictive insights into disease spread and the impact of vaccination strategies. This paper explored the significance of mathematical modeling in epidemic control efforts, focusing on the interplay between vaccination strategies, disease transmission rates, and population immunity. To facilitate meaningful comparisons of vaccination strategies, we maintained a consistent framework by fixing the vaccination capacity to vary from 10 to 100% of the total population. As an example, at a 50% vaccination capacity, the pulse strategy averted approximately 45.61% of deaths, while continuous and hybrid strategies averted around 45.18 and 45.69%, respectively. Sensitivity analysis further indicated that continuous vaccination has a more direct impact on reducing the basic reproduction number $ R_0 $ compared to pulse vaccination. By analyzing key parameters such as $ R_0 $, pulse vaccination coefficients, and continuous vaccination parameters, the study underscores the value of mathematical modeling in shaping public health policies and guiding decision-making during disease outbreaks.

Disinfectants efficacy in reducing pathogens related to health-care infection associated in universities hospitals of Gorgan, North of Iran.

BACKGROUND: Disinfection has a fundamental role in the control of pathogens in the hospital environment. This study was designed to assess the efficacy and functional impact of disinfectants in reducing pathogens related to healthcare associated infections (HAIs) in hospitals. METHODS: This observation study was conducted at three university hospitals in Gorgan, Iran, from May to Oct 2023. The data including used disinfectants and microbiological examination were obtained from the infection control unit of each hospital. RESULTS: The results showed that a variety of disinfectants from intermediate to high levels were employed in accordance with the World Health Organization (WHO) protocols. The microbial result revealed that 31.6% (286 out of 906) of the sample had at least one microorganism. Among identified organisms, Bacillus spp. were the predominant species followed by Staphylococcus epidermis, fungus genera, Enterobacter spp., Enterococcus spp., Pseudomonas spp., Escherichia coli, Alcaligenes spp., Staphylococcus aureus, Citrobacter spp., Corynebacterium spp., Klebsiella spp., Acinetobacter spp., Micrococcus spp., Staphylococcus saprophyticus, and Serratias spp. The highest prevalence rates of microorganisms were observed in the wards of ICU, emergency, internal medicine, and women's ward. The chi-square test revealed a significant relationship between the presence of organisms and hospital wards (P < 0.05). CONCLUSION: The presence of pathogens indicates a defect in the disinfection process, probably due to both little attention to disinfection protocols and multidrug resistance. It is not yet possible to eliminate pathogens from the hospital environment, but it can be minimized by education intervention, standardizing disinfecting processes, and monitoring by the infection control committee.

Juvenile agile frogs spatially avoid ranavirus-infected conspecifics.

Exposure to contagious pathogens can result in behavioural changes, which can alter the spread of infectious diseases. Healthy individuals can express generalized social distancing or avoid the sources of infection, while infected individuals can show passive or active self-isolation. Amphibians are globally threatened by contagious diseases, yet their behavioural responses to infections are scarcely known. We studied behavioural changes in agile frog (Rana dalmatina) juveniles upon exposure to a Ranavirus (Rv) using classic choice tests. We found that both non-infected and Rv-infected focal individuals spatially avoided infected conspecifics, while there were no signs of generalized social distancing, nor self-isolation. Avoidance of infected conspecifics may effectively hinder disease transmission, protecting non-infected individuals as well as preventing secondary infections in already infected individuals. On the other hand, the absence of self-isolation by infected individuals may facilitate it. Since infection status did not affect the time spent near conspecifics, it is unlikely that the pathogen manipulated host behaviour. More research is urgently needed to understand under what circumstances behavioural responses can help amphibians cope with infections, and how that affects disease dynamics in natural populations.

Modern agriculture and One Health.

BACKGROUND: The development of modern agriculture has significantly contributed to improving global food security and safety, alleviating poverty, and enhancing human health and livelihoods. However, the rapid advancement of modern agriculture has also brought about various challenges that limit its sustainable development. This commentary aims to discuss these issues through the One Health lens, and provide valuable insights for balancing modern agricultural activities with the need to protect and promote the health of all the sectors. MAIN TEXT: This commentary explores the multifaceted impacts of modern agriculture on social development, as well as the associated various health challenges and environmental impacts within the One Health framework. Key issues include ecosystem degradation, increased risk of interspecies disease transmission like zoonoses, reverse zoonoses, and vector-borne diseases, and the escalated threat of antimicrobial resistance due to intensified agricultural production and increased antimicrobial use. To address these challenges, this commentary outlines potential solutions anchored in the development and implementation of modern technologies and good agricultural practices, such as precision farming, integrated pest management, biosecurity measures, vaccination programs, as well as surveillance and early detection of health risks. CONCLUSIONS: Good agricultural practices supported by scientific and technological advancements are essential for aligning productivity with the One Health vision, ensuring the health and resilience of all the sectors. Enhancing stakeholder education, strengthening regulatory frameworks, and providing supportive policies and infrastructure for farmers to adopt sustainable practices are crucial for the long-term viability of agrifood systems. The Food and Agriculture Organization of the United Nations plays a pivotal role in guiding this sustainable transformation through the One Health approach.

Spatiotemporal modeling of COVID-19 spread: unveiling socioeconomic disparities and patterns, across social classes in the urban population of Kermanshah, Iran.

Background: Presenting ongoing outbreaks and the potential for their spread to nearby neighborhoods and social classes may offer a deeper understanding, enable a more efficient reaction to outbreaks, and enable a comprehensive understanding of intricate details for strategic response planning. Hence, this study explored the spatiotemporal spread of COVID-19 outbreaks and prioritization of the risk areas among social classes in the Kermanshah metropolis. Methods: In this cross-sectional study, the data of 58.951 COVID-19-infected patients were analyzed. In 2020, out of 24.849 infected patients, 10.423 were females, 14,426 were males, and in 2021, 15.714 were females, and 18,388 were males. To categorize social classes (working, middle, and upper), we utilized economic, social, cultural, and physical indicators. Our analysis utilized Arc/GIS 10.6 software along with statistical tests, including standard distance (SD), mean center (MC), standard deviational ellipse (SDE), and Moran's I. Results: The results revealed that the average epicenter of the disease shifted from the city center in 2020-2021 to the eastern part of the city in 2021. The results related to the SD of the disease showed that more than 70% of the patients were concentrated in this area of the city. The SD of COVID-19 in 2020 compared to 2021 also indicated an increased spread throughout the city. Moran's I test and the hotspot test results showed the emergence of a clustered pattern of the disease. In the Kermanshah metropolis, 58,951 COVID-19 cases were recorded, with 55.76% males and 44.24% females. Social class distribution showed 28.86% upper class, 55.95% middle class, and 15.19% working class. A higher disease prevalence among both males and females in the upper class compared to others. Discussion: Our study designed a spatiotemporal disease spread model, specifically tailored for a densely populated urban area. This model allows for the observation of how COVID-19 propagates both spatially and temporally, offering a deeper understanding of outbreak dynamics in different neighborhoods and social classes of the city.

FlightTrackAI: a robust convolutional neural network-based tool for tracking the flight behaviour of Aedes aegypti mosquitoes.

Monitoring the flight behaviour of mosquitoes is crucial for assessing their fitness levels and understanding their potential role in disease transmission. Existing methods for tracking mosquito flight behaviour are challenging to implement in laboratory environments, and they also struggle with identity tracking, particularly during occlusions. Here, we introduce FlightTrackAI, a robust convolutional neural network (CNN)-based tool for automatic mosquito flight tracking. FlightTrackAI employs CNN, a multi-object tracking algorithm, and interpolation to track flight behaviour. It automatically processes each video in the input folder without supervision and generates tracked videos with mosquito positions across the frames and trajectory graphs before and after interpolation. FlightTrackAI does not require a sophisticated setup to capture videos; it can perform excellently with videos recorded using standard laboratory cages. FlightTrackAI also offers filtering capabilities to eliminate short-lived objects such as reflections. Validation of FlightTrackAI demonstrated its excellent performance with an average accuracy of 99.9%. The percentage of correctly assigned identities after occlusions exceeded 91%. The data produced by FlightTrackAI can facilitate analysis of various flight-related behaviours, including flight distance and volume coverage during flights. This advancement can help to enhance our understanding of mosquito ecology and behaviour, thereby informing targeted strategies for vector control.

HIV drug resistance, viral suppression, and survival in children living with HIV in Brazil.

INTRODUCTION: Mutations associated with HIV drug resistance (DR) affect clinical outcomes. Understanding the prevalence of HIV DR and its association with viral suppression and survival in the paediatric population is key to inform patient care and health policies. METHODS: We used Brazilian monitoring systems to identify genotyping tests performed in children living with HIV aged ≤18 months between 2009 and 2020. We categorized HIV DR using three criteria: any HIV DR (R1), DR to nevirapine or efavirenz (R2), and DR to at least one antiretroviral recommended for children with HIV in Brazilian guidelines (R3). We investigated factors associated with HIV DR, viral suppression, and survival up to 3 years old using multivariable models. Lastly, we describe the annual prevalence of each type of HIV DR in Brazilian children with HIV between 2009 and 2020. RESULTS: We included 1152 children with HIV with a median age of 5 months at genotype testing; 57% were females. R1 was observed in 30%, R2 in 17%, and R3 in 21%. Children with HIV whose birth parents were exposed to nevirapine or efavirenz before delivery had higher odds of R2 (odds ratio 3.4; 95% confidence interval [CI] 1.1-10.8). Children with HIV with R1 or R3 had higher rates of death than those with HIV with no HIV DR in the adjusted models (adjusted hazard ratios 4.7 [95% CI 1.6-13.9] and 4.1 [95% CI 1.4-12.4], respectively). The prevalence of resistance to nevirapine and efavirenz peaked in 2015. Over time, the prevalence of genotyping tests with no detected resistance varied between 57% and 87%. CONCLUSION: HIV DR is highly prevalent in children with HIV and is associated with lower survival.

Immunogenicity of a Birth Dose of Hepatitis B Vaccine in Kinshasa, Democratic Republic of Congo: A Randomised, Controlled Trial.

The WHO recommends hepatitis B birth-dose vaccination (HepB-BD), but it is not routinely given in most sub-Saharan African countries. We aimed to assess the immunogenicity of HepB-BD in addition to the existing hepatitis B vaccine (HepB3) schedule in Kinshasa, Democratic Republic of Congo among HBV-unexposed and HBV-exposed infants. Using an open-label, randomised, controlled design, HBV-unexposed infants were randomised (1:1) to receive the standard HepB3 vaccine series (group U3), or to receive HepB-BD in addition to HepB3 (group U4). A supplemental cohort of HBV-exposed infants (group E4) received HepB-BD and HepB3. We compared the proportion of infants with protective antibodies against HBV (HBV surface antibody ≥ 10 mIU/mL) between groups U3 and U4 and groups U4 and E4 at 12 months of age. Between August 20 and October 9, 2019, we enrolled 281 mother/infant dyads; 88 (31.3%) returned at 12 months. Most infants had protective antibodies against HBV at 12 months: 92.9% (75.7%-98.2%) in group U3, 85.7% (67.5%-94.5%) in group U4 and 96.9% (95% CI: 81.2%-99.6%) in group E4. Trends held in estimates adjusted for loss-to-follow-up (LTFU) and baseline imbalance across groups. In this first randomised trial assessing the addition of HepB-BD to the hepatitis B vaccine schedule in SSA, we found that HBV-unexposed infants who received the 3-dose and 4-dose vaccine series had similar immunogenicity against HBV at 12 months. A high proportion of infants, and notably HBV-exposed infants, had protective antibodies. Though extrapolation of findings may be limited by LTFU, this study adds real-world evidence regarding HepB-BD implementation in sub-Saharan Africa. Trial Registration: ClinicalTrials.gov identifier: NCT03897946.

Occupational pressures of frontline workers enforcing COVID-19 pandemic measures in Ontario and Quebec, Canada.

BACKGROUND: During the COVID-19 pandemic, low-wage public-facing frontline workers (FLWs), such as grocery store clerks, were required to monitor retail customers and enforce COVID-19 protocols. OBJECTIVE: This analysis aimed to examine FLWs experiences of enforcing COVID-19 pandemic measures. METHODS: Between September 2020 and March 2021, in Ontario and Quebec (Canada), we conducted in-depth interviews about customer-related work and health risks with FLWs who interacted with the public (n = 40) and their supervisors (n = 16). Using a lens of situational analysis, verbatim transcripts were coded according to recurring topics. RESULTS: We found that enforcing public health measures placed already-precarious workers in difficult occupational health circumstances. Enforcement of measures created additional workplace responsibilities, stress, and exposed them to potentially negative reactions from customers. CONCLUSIONS: Interventions to better support these workers and improved methods of protection are discussed.

Identification of HIV infection in two solid organ recipients three years after transplantation / Identificación de infección por el virus de la inmunodeficiencia humana en dos receptores de órgano sólido tres años después del trasplante

Routine screening of organ donors to detect human immunodeficiency virus (HIV) infection has detected the rare transmission of the virus through organ transplantation. However, despite routine screening, HIV transmission remains a risk in organ transplantation since, unlike tissues, solid organs cannot be processed, disinfected, or modified to inactivate infectious pathogens. A case of possible transmission of HIV by organ transplant is described below, from a previously seronegative donor to two recipients.

El examen de rutina de los donantes de órganos para detectar la infección por el virus de la inmunodeficiencia humana (HIV) ha hecho que la transmisión del virus mediante el trasplante de órganos sea poco común. Sin embargo, a pesar de las pruebas de detección de rutina, la transmisión del HIV continúa siendo un riesgo del trasplante de órganos ya que, a diferencia de los tejidos, los órganos sólidos no se pueden procesar, desinfectar, ni modificar para inactivar patógenos infecciosos. A continuación, se describe un caso de posible transmisión de HIV por trasplante de órganos de un donante previamente seronegativo a dos de sus receptores.

Disentangling social, environmental, and zoonotic transmission pathways of a gastrointestinal protozoan (Blastocystis spp.) in northeast Madagascar.

OBJECTIVES: Understanding disease transmission is a fundamental challenge in ecology. We used transmission potential networks to investigate whether a gastrointestinal protozoan (Blastocystis spp.) is spread through social, environmental, and/or zoonotic pathways in rural northeast Madagascar. MATERIALS AND METHODS: We obtained survey data, household GPS coordinates, and fecal samples from 804 participants. Surveys inquired about social contacts, agricultural activity, and sociodemographic characteristics. Fecal samples were screened for Blastocystis using DNA metabarcoding. We also tested 133 domesticated animals for Blastocystis. We used network autocorrelation models and permutation tests (network k-test) to determine whether networks reflecting different transmission pathways predicted infection. RESULTS: We identified six distinct Blastocystis subtypes among study participants and their domesticated animals. Among the 804 human participants, 74% (n = 598) were positive for at least one Blastocystis subtype. Close proximity to infected households was the most informative predictor of infection with any subtype (model averaged OR [95% CI]: 1.56 [1.33-1.82]), and spending free time with infected participants was not an informative predictor of infection (model averaged OR [95% CI]: 0.95 [0.82-1.10]). No human participant was infected with the same subtype as the domesticated animals they owned. DISCUSSION: Our findings suggest that Blastocystis is most likely spread through environmental pathways within villages, rather than through social or animal contact. The most likely mechanisms involve fecal contamination of the environment by infected individuals or shared food and water sources. These findings shed new light on human-pathogen ecology and mechanisms for reducing disease transmission in rural, low-income settings.

Basic Reproduction Number (R0), Doubling Time, and Daily Growth Rate of the COVID-19 Epidemic: An Echological Study.

Introduction: In infectious diseases, there are essential indices used to describe the disease state. In this study, we estimated the basic reproduction number, R0, peak level, doubling time, and daily growth rate of COVID-19. Methods: This ecological study was conducted in 5 provinces of Iran. The daily numbers of new COVID-19 cases from January 17 to February 8, 2020 were used to determine the basic reproduction number (R0), peak date, doubling time, and daily growth rates in all five provinces. A sensitivity analysis was conducted to estimate epidemiological parameters. Result: The highest and lowest number of deaths were observed in Hamedan (657 deaths) and Chaharmahal and Bakhtiari (54 deaths) provinces, respectively. The doubling time of confirmed cases in Kermanshah and Hamedan ranged widely from 18.59 days (95% confidence interval (CI): 17.38, 20) to 76.66 days (95% CI: 56.36, 119.78). In addition, the highest daily growth rates of confirmed cases were observed in Kermanshah (0.037, 95% CI: 0.034, 0.039) and Sistan and Baluchestan (0.032, 95% CI: 0.030, 0.034) provinces. Conclusion: In light of our findings, it is imperative to tailor containment strategies to the unique epidemiological profiles of each region in order to effectively mitigate the spread and impact of COVID-19. The wide variation in doubling times underscores the importance of flexibility in public health responses. By adapting measures to local conditions, we can better address the evolving dynamics of the pandemic and safeguard the well-being of communities.

Risk of SARS-CoV-2 infection in professional settings, shops, shared transport, and leisure activities in France, 2020-2022.

PURPOSE: The aim of the study was to identify settings associated with SARS-CoV-2 transmission throughout the COVID-19 pandemic in France. METHODS: Cases with recent SARS-CoV-2 infection were matched with controls (4:1 ratio) on age, sex, region, population size, and calendar week. Odds ratios for SARS-CoV-2 infection were estimated for nine periods in models adjusting for socio-demographic characteristics, health status, COVID-19 vaccine, and past infection. RESULTS: Between October 27, 2020 and October 2, 2022, 175,688 cases were matched with 43,922 controls. An increased risk of infection was documented throughout the study for open-space offices compared to offices without open space (OR range across the nine periods: 1.12 to 1.57) and long-distance trains (1.25 to 1.88), and during most of the study for convenience stores (OR range in the periods with increased risk: 1.15 to 1.44), take-away delivery (1.07 to 1.28), car-pooling with relatives (1.09 to 1.68), taxis (1.08 to 1.89), airplanes (1.20 to 1.78), concerts (1.31 to 2.09) and night-clubs (1.45 to 2.95). No increase in transmission was associated with short-distance shared transport, car-pooling booked over platforms, markets, supermarkets and malls, hairdressers, museums, movie theatres, outdoor sports, and swimming pools. The increased risk of infection in bars and restaurants was no longer present in restaurants after reopening in June 2021. It persisted in bars only among those aged under 40 years. CONCLUSION: Closed settings in which people are less likely to wear masks were most affected by SARS-CoV-2 transmission and should be the focus of air quality improvement. CLINICALTRIALS: GOV (03/09/2022): NCT04607941.

An optimized strategy triggered at the 2nd immunization visit to prevent HIV acquisition by breastfeeding: a phase 2 trial in Burkina Faso (PREVENIR-PEV).

BACKGROUND: Mother-to-child transmission of HIV during breastfeeding remains a challenge in low- and middle-income countries (LMIC). A prevention package was initiated during the highly attended 2nd visit of the Expanded Program of Immunisation (EPI-2) to identify the undiagnosed infants living with HIV and reduce the postnatal transmission of infant exposed to HIV. METHODS: PREVENIR-PEV is a non-randomized phase II clinical trial conducted at two health centres in Bobo Dioulasso (Burkina Faso). The study recruited mothers living with HIV aged 15 years and older with their singleton breastfed infants. During EPI-2 (at 8 weeks) and upon signature of the informed consent, a point-of-care early infant diagnosis (EID) was performed. HIV exposed uninfected (HEU) infants were followed-up until 12 months of age. High risk HEU infants (i.e., whose maternal viral load ≥ 1000 cp/mL at EPI-2 or M6) received an extended postnatal prophylaxis (PNP) with lamivudine until end of follow-up or the end of breastfeeding. RESULTS: Between 4 December 2019 and 4 December 2020, 118 mothers living with HIV-1 were identified, and 102 eligible mother/infant pairs had their infants tested for HIV EID. Six infants were newly diagnosed with HIV, and 96 HEU infants were followed-up for 10 months. Among the participants followed-up, all mothers were prescribed antiretrovirals. All 18 infants eligible for PNP at either EPI-2 or 6 months (M6) were initiated on lamivudine. No HIV transmission occurred, and no serious adverse events were reported in infants receiving lamivudine. CONCLUSIONS: The PREVENIR-PEV prevention package integrated into existing care is safe and its implementation is feasible in a LMIC with a low HIV prevalence. More research is needed to target mother/infant pairs not adhering to the intervention proposed in this trial. TRIAL REGISTRATION: NCT03869944; first registered on 11/03/2019.

A multidisciplinary analysis of over 53,000 fascioliasis patients along the 1995-2019 countrywide spread in Vietnam defines a new epidemiological baseline for One Health approaches.

Fascioliasis, only foodborne trematodiasis of worldwide distribution, is caused by Fasciola hepatica and F. gigantica, liver flukes transmitted by freshwater snails. Southern and southeastern Asia is an emerging hot spot of F. gigantica, despite its hitherto less involvement in human infection. In Vietnam, increasing cases have been reported since 1995, whereas only sixteen throughout 1800-1994. A database was created to include epidemiological data of fascioliasis patients from the 63 Vietnam provinces throughout 1995-2019. Case profiles were based on serology, symptoms, eosinophilia, imaging techniques, stool egg finding, and post-specific-treatment recovery. Radio broadcasting about symptoms and costless diagnosis/treatment led patients to hospitals after symptom onset. Yearly case numbers were modelled and spatio-temporally analyzed. Missing data and confounders were assessed. The countrywide spread has no precedent. It started in the central coast, including 53,109 patients, mostly adults and females. Seasonality, linked to vegetable consumption, peaks in June, although the intensity of this peak differs according to relief/climatic zones. Incidence data and logistic regression curves are obtained for the first time in human fascioliasis. Fasciolid hybrids accompanying the spreading F. gigantica flukes, and climate change assessed by risk index correlations, are both ruled out as outbreak causes. Human-guided movements of livestock from an original area prove to be the way used by fasciolids and lymnaeid vectors to expand geographically. Radix viridis, a highly efficient transmitting and colonizing vector, played a decisive role in the spread. The use of irrigated crop fields, widely inhabited by R. viridis, for livestock grazing facilitated the transmission and spread of the disease. General physician awareness and diagnostic capacity improvement proved the successful impact of such knowledge transfer in facilitating and increasing patient infection detection. Information, education and communication to the public by radio broadcasting demonstrated to be very helpful. Fasciola gigantica is able to cause epidemic and endemic situations similar to F. hepatica. The magnitude of the human outbreak in Vietnam is a health wake-up call for southern and southeastern countries of Asia which present the highest human population densities with increasing food demands, uncontrolled livestock inter-country exchange, foreign import practices, and monsoon's increasing climate change impact.