Infection pattern, case fatality rate and spread of Lassa virus in Nigeria.

BACKGROUND: Lassa fever (LF) is a zoonotic infectious disease of public concern in Nigeria. The infection dynamics of the disease is not well elucidated in Nigeria. This study was carried out to describe the pattern of infection, case fatality rate and spread of lassa virus (LASV) from 2017 to 2020. METHODS: Weekly epidemiological data on LF from December, 2016 to September, 2020 were obtained from Nigeria Centre for Disease Control. The number of confirmed cases and deaths were computed according to months and states. Descriptive statistics was performed and case fatality rate was calculated. Distribution and spread maps of LF over the four years period was performed on ArcMap 10.7. RESULTS: A total of 2787 confirmed cases and 516 deaths were reported in Nigeria from December, 2016 to September, 2020. Increase in number of cases and deaths were observed with 298, 528, 796 and 1165 confirmed cases and 79, 125, 158 and 158 deaths in 2017, 2018, 2019 and 2020 respectively. Over 60% of the cases were reported in two states, Edo and Ondo states. The LF cases spread from 19 states in 2017 to 32 states and Federal Capital Territory (FCT) in 2020. Ondo state (25.39%) had the highest of deaths rate from LF over the four years. Case fatality rate (CFR) of LF was highest in 2017 (26.5%) with CFR of 23.7, 19.6 and 13.4% in 2018, 2019 and 2020 respectively. The peak of infection was in the month of February for the four years. Infections increases at the onset of dry season in November and decline till April when the wet season sets-in. CONCLUSION: There is an annual increase in the number of LASV infection across the states in Nigeria. There is need to heighten control strategies through the use of integrated approach, ranging from vector control, health education and early diagnosis.

Human impact on the diversity and virulence of the ubiquitous zoonotic parasite Toxoplasma gondii.

A majority of emerging infectious diseases in humans are zoonoses. Understanding factors that influence the emergence and transmission of zoonoses is pivotal for their prevention and control. Toxoplasma gondii is one of the most widespread zoonotic pathogens known today. Whereas only a few genotypes of T. gondii dominate in the Northern Hemisphere, many genotypes coexist in South America. Furthermore, T. gondii strains from South America are more likely to be virulent than those from the Northern Hemisphere. However, it is not clear what factor(s) shaped modern-day genetic diversity and virulence of T. gondii Here, our analysis suggests that the rise and expansion of farming in the past 11,000 years established the domestic cat/mouse transmission cycle for T. gondii, which has undoubtedly played a significant role in the selection of certain linages of T. gondii Our mathematical simulations showed that within the domestic transmission cycle, intermediately mouse-virulent T. gondii genotypes have an adaptive advantage and eventually become dominant due to a balance between lower host mortality and the ability to superinfect mice previously infected with a less virulent T. gondii strain. Our analysis of the global type II lineage of T. gondii suggests its Old World origin but recent expansion in North America, which is likely the consequence of global human migration and trading. These results have significant implications concerning transmission and evolution of zoonotic pathogens in the rapidly expanding anthropized environment demanded by rapid growth of the human population and intensive international trading at present and in the future.

Occupational Fatalities Due to Mammal-Related Accidents in Japan, 2000-2019.

INTRODUCTION: Animal-related fatal accidents occur annually while individuals are outside working. This study intended to evaluate the trends of occupational fatal accidents related to mammals and compare them with nonoccupational accidents. METHODS: We collected occupational and nonoccupational fatalities related to mammals between 2000 and 2019 from data on fatal occupational accident cases certified by the Ministry of Health, Labor and Welfare, Japan, in addition to other statistics from relevant ministries, media reports such as newspapers, and academic case reports. RESULTS: A total of 109 fatal accidents related to mammals were confirmed as occurring during work, and 129 were confirmed as taking place outside of work. Of the former, accidents among livestock farmers and horse racing-related workers accounted for about half. Among the accidents not related to work, dog attacks, infectious diseases from cats or dogs, traffic accidents with wild animals, and bear attacks during wild vegetable picking were common. Deaths from infectious diseases caused by dogs and cats have rarely been reported in the mass media. CONCLUSIONS: Although the number of fatal occupational accidents related to mammals is not large, we concluded that it is necessary to continue preventive measures centered on accidents at livestock farms and in horse racing-related workplaces. It is also necessary to inform people about the risks of infectious diseases mediated by dogs and cats.

Origins of the 1918 Pandemic: Revisiting the Swine "Mixing Vessel" Hypothesis.

How influenza A viruses host-jump from animal reservoir species to humans, which can initiate global pandemics, is a central question in pathogen evolution. The zoonotic and spatial origins of the influenza virus associated with the "Spanish flu" pandemic of 1918 have been debated for decades. Outbreaks of respiratory disease in US swine occurred concurrently with disease in humans, raising the possibility that the 1918 virus originated in pigs. Swine also were proposed as "mixing vessel" intermediary hosts between birds and humans during the 1957 Asian and 1968 Hong Kong pandemics. Swine have presented an attractive explanation for how avian viruses overcome the substantial evolutionary barriers presented by different cellular environments in humans and birds. However, key assumptions underpinning the swine mixing-vessel model of pandemic emergence have been challenged in light of new evidence. Increased surveillance in swine has revealed that human-to-swine transmission actually occurs far more frequently than the reverse, and there is no empirical evidence that swine played a role in the emergence of human influenza in 1918, 1957, or 1968. Swine-to-human transmission occurs periodically and can trigger pandemics, as in 2009. But swine are not necessary to mediate the establishment of avian viruses in humans, which invites new perspectives on the evolutionary processes underlying pandemic emergence.

Macroecology of birds potentially susceptible to West Nile virus.

Zoonotic diseases transmitted by wildlife affect biological conservation, public and animal health, and the economy. Current research efforts are aimed at finding wildlife pathogens at a given location. However, a meta-analytical approach may reveal emerging macroecological patterns in the host-pathogen relationship at different temporal and spatial scales. West Nile virus (WNV) is a pathogen with worldwide detrimental impacts on bird populations. To understand macroecological patterns driving WNV infection, we aimed to recognize unknown competent reservoirs using three disease metrics-serological prevalence (SP), molecular prevalence (MP) and mortality (M)-and test if these metrics are correlated with the evolutionary history, geographical origin of bird species, viral strain, time-space and methodology. We performed a quantitative review of field studies on birds sampled for WNV. We obtained 4945 observations of 949 species from 39 countries. Our analysis supported the idea that MP and M are good predictors of reservoir competence, and allowed us to identify potential competent reservoirs. Furthermore, results indicated that the variability of these metrics was attributable to phylogeny, time-space and sample size. A macroecological approach is needed to recognize susceptible species and competent reservoirs, and to identify other factors driving zoonotic diseases originating from wildlife.

Fatal and non-fatal animal-related injuries and illnesses to workers, United States, 2011-2014.

BACKGROUND: Study provides update of national estimates for work-related fatal injuries and non-fatal injuries and illnesses by animals in US. METHODS: Between 2011 and 2014, injuries and illnesses were retrieved from US Department of Labor and were translated to economic losses using National Safety Council estimates. RESULTS: Total of 222 fatalities (36% by cattle and other bovines) and 71 460 non-fatal injuries and illnesses (38% by insects, arachnids, mites) were identified from animal sources. For non-fatal injuries and illnesses from primary animal sources, annual incidence rates were 1.5-1.6/10 000 full-time workers and annual median days lost from work were 3-4 days. Work-related costs were $222M for fatalities and $2.8B for non-fatal injuries and illnesses that resulted in at least 1 day lost from work. CONCLUSIONS: Study provides evidence of specific animals contributing to more severe injuries and potential for more severe injuries when there is more than one source of injury.

Identification of human neutralizing antibodies against MERS-CoV and their role in virus adaptive evolution.

The newly emerging Middle East Respiratory Syndrome coronavirus (MERS-CoV) causes a Severe Acute Respiratory Syndrome-like disease with ∼43% mortality. Given the recent detection of virus in dromedary camels, zoonotic transfer of MERS-CoV to humans is suspected. In addition, little is known about the role of human neutralizing Ab (nAb) pressure as a driving force in MERS-CoV adaptive evolution. Here, we used a well-characterized nonimmune human Ab-phage library and a panning strategy with proteoliposomes and cells to identify seven human nAbs against the receptor-binding domain (RBD) of the MERS-CoV Spike protein. These nAbs bind to three different epitopes in the RBD and human dipeptidyl peptidase 4 (hDPP4) interface with subnanomolar/nanomolar binding affinities and block the binding of MERS-CoV Spike protein with its hDPP4 receptor. Escape mutant assays identified five amino acid residues that are critical for neutralization escape. Despite the close proximity of the three epitopes on the RBD interface, escape from one epitope did not have a major impact on neutralization with Abs directed to a different epitope. Importantly, the majority of escape mutations had negative impacts on hDPP4 receptor binding and viral fitness. To our knowledge, these results provide the first report on human nAbs against MERS-CoV that may contribute to MERS-CoV clearance and evolution. Moreover, in the absence of a licensed vaccine or antiviral for MERS, this panel of nAbs offers the possibility of developing human mAb-based immunotherapy, especially for health-care workers.

Risks of Death and Severe Disease in Patients With Middle East Respiratory Syndrome Coronavirus, 2012-2015.

Middle East respiratory syndrome coronavirus (MERS-CoV) is an emerging pathogen, first recognized in 2012, with a high case fatality risk, no vaccine, and no treatment beyond supportive care. We estimated the relative risks of death and severe disease among MERS-CoV patients in the Middle East between 2012 and 2015 for several risk factors, using Poisson regression with robust variance and a bootstrap-based expectation maximization algorithm to handle extensive missing data. Increased age and underlying comorbidity were risk factors for both death and severe disease, while cases arising in Saudi Arabia were more likely to be severe. Cases occurring later in the emergence of MERS-CoV and among health-care workers were less serious. This study represents an attempt to estimate risk factors for an emerging infectious disease using open data and to address some of the uncertainty surrounding MERS-CoV epidemiology.

Alveococcosis of the liver - strategy of surgical treatment with special focus on liver transplantation.

BACKGROUND: Echinococcosis is a zoonosis caused by infestation with any of 4 (of the 16) members of the Echinococcus genus, namely Echinococcus granulosus, Echinococcus multilocularis, Echinococcus oligarthus, and Echinococcus vogelii. The aim of this retrospective analysis was to present the outcomes of patients undergoing liver resection and liver transplantation (LT) for E. multilocularis infection. METHODS: A total of 44 patients who underwent surgical treatment of E. multilocularis infection in the period between 1989 and 2014 were included in the study cohort and retrospectively analyzed. RESULTS: LT was performed in 22 patients (50.0%), including 4 of 26 patients undergoing initial non-transplant management. Non-transplant procedures comprised liver resection in 23 patients (88.5%), diagnostic laparoscopy in 2 (7.7%), and left adrenalectomy in 1 patient (3.8%). Post-transplantation survival rates were 90%, 85%, and 75% at 1, 5, and 10 years, respectively. CONCLUSION: In conclusion, LT for E. multilocularis infection is a safe and effective treatment method.

Current status of rabies and prospects for elimination.

Rabies is one of the most deadly infectious diseases, with a case-fatality rate approaching 100%. The disease is established on all continents apart from Antarctica; most cases are reported in Africa and Asia, with thousands of deaths recorded annually. However, the estimated annual figure of almost 60,000 human rabies fatalities is probably an underestimate. Almost all cases of human rabies result from bites from infected dogs. Therefore, the most cost-effective approach to elimination of the global burden of human rabies is to control canine rabies rather than expansion of the availability of human prophylaxis. Mass vaccination campaigns with parenteral vaccines, and advances in oral vaccines for wildlife, have allowed the elimination of rabies in terrestrial carnivores in several countries worldwide. The subsequent reduction in cases of human rabies in such regions advocates the multidisciplinary One Health approach to rabies control through the mass vaccination of dogs and control of canine populations.

CSCI/RCPSC Henry Friesen lecture: controlling infectious diseases through vaccination.

Infectious diseases continue to cause significant morbidity and mortality in both animals and humans. Indeed, every year infectious diseases cost the global economy billions of dollars in losses and are responsible for approximately one-third of all human deaths. These deaths occur from routine infections, hospital acquired infections (approximately 100,000 deaths occur annually in North America due to hospital-acquired infections), occasional pandemics or regional outbreaks. The most recent regional outbreak is Ebola in West Africa. This infection has caused significant challenges for the regional health care community and has had a global impact. The challenge in the control of infectious diseases is not only due to routine infections but also to the continued emergence and re-emergence of infectious diseases. These new threats occur on a regular basis with approximately thirty new emerging or re-emerging diseases recorded in the last thirty years. The majority of these emerging diseases are zoonotic (over 70%) causing even greater challenges to their control in humans and animals.

Causes of mortality in backyard chickens in northern California: 2007-2011.

A 5-yr retrospective study was conducted to characterize the spectrum of diseases causing mortality in 1301 backyard chickens submitted to the California Animal Health and Food Safety laboratory in Davis, California. Infectious diseases were diagnosed in the majority (60.4%). Viral diseases comprised 50% of the infectious entities, followed by bacterial diseases with an incidence of 39%. Marek's disease in the viral group and Escherichia coli in the bacterial group were the most commonly diagnosed infectious diseases. Zoonotic agents including Aspergillus sp., Salmonella sp., Listeria sp., Mycobacterium sp., Candida sp., and Baylisascaris sp. were detected in 46 (3.5%) birds. Among noninfectious conditions, fatty liver hemorrhagic syndrome and reproductive tract adenocarcinoma were the leading causes of mortality. This analysis provides an overview of backyard chicken diseases for practitioners and avian pathologists working with backyard poultry. In addition, this study illustrates that backyard chickens do not seem to pose a major risk to public health, although zoonoses do comprise a notable portion (5.9% of all infectious cases) of isolated agents.

Integrating animal health and foodborne disease surveillance.

The control of foodborne diseases from an animal source has become an important part of public health policy. Since the agents that cause these diseases originate in animals, Veterinary Services, as well as Public Health Services, must be involved in their control. Control programmes should be established either through cooperation between the two Services or by the consolidation of all those involved into a single food control agency. Surveillance is an important part of these control programmes. The following questions must be addressed when planning an effective surveillance programme. What is the relative incidence, morbidity, mortality and economic cost of the foodborne disease in humans? Is the animal population the exclusive or a significant source of the human foodborne infection? What kind of surveillance is needed to identify the disease-causing agent in the animal population? Are we interested in identifying all cases of a disease in order to eradicate it or is our aim to reduce its incidence in the animal population? Do we have the ability to control the disease in the animal population? What disease detection tests are available? What are the sensitivity, specificity and cost of these diagnostic tests? Finally, does the country, region or agency involved have the legal, financial and educational resources to carry out this surveillance and follow it up with appropriate action? After these questions have been resolved,the veterinary and public health sectors must jointly decide if surveillance and control are feasible. If so, they can then begin to develop an appropriate programme.

Did transmission of Helicobacter pylori from humans cause a disease outbreak in a colony of Stripe-faced Dunnarts (Sminthopsis macroura)?

Since the discovery that Helicobacter pylori causes a range of pathologies in the stomachs of infected humans, it has become apparent that Helicobacters are found in a diverse range of animal species where they are frequently associated with disease. In 2003 and 2004, there were two outbreaks of increased mortality associated with gastric bleeding and weight-loss in a captive colony of the Australian marsupial, the Stripe-faced Dunnart (Sminthopsis macroura). The presence of gastric pathology led to an investigation of potential Helicobacter pathogenesis in these animals. Histological examination revealed the presence of gastritis, and PCR analysis confirmed the presence of Helicobacter infection in the stomachs of these marsupials. Surprisingly, sequencing of 16S rRNA from these bacteria identified the species as H. pylori and PCR confirmed the strain to be positive for the important pathogenesis factor, cagA. We therefore describe, for the first time, an apparent reverse zoonotic infection of Stripe-faced Dunnarts with H. pylori. Already prone to pathological effects of stress (as experienced during breeding season), concomitant H. pylori infection appears to be a possible essential but not sufficient co-factor in prototypic gastric bleeding and weight loss in these marsupials. The Stripe-faced Dunnart could represent a new model for investigating Helicobacter-driven gastric pathology. Infections from their human handlers, specifically of H. pylori, may be a potential risk to captive colonies of marsupials.

Zoonotic and reverse zoonotic transmission of severe acute respiratory syndrome coronavirus 2: a review and implications for Africa.

There is an urgent need to properly understand the transmission dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the event of continuous rise in morbidity in both humans and animals as well as an increase in the mortality rate in man. Since the novel SARS-CoV-2 emerged in Wuhan, China with its global spread in over 200 countries, several studies have been published on the epidemiology of the virus in man with limited information on the roles of animals and the possibility of reverse zoonosis. We therefore collected published research literature on COVID-19 from public search engines for information on SARS-CoV-2 in animals and reverse zoonosis from man. A critical and thorough study appraisal/evaluation was performed to include recent quality publications that focus on the scope of this write-up including zoonosis and reverse zoonosis of SARS-CoV-2. We highlighted what is known about SARS-CoV-2 in animals, identify gaps for future research, summarized possible reverse zoonotic transmission of SARS-CoV-2 from man to animals and included the likely implications of our summary for Africa, despite the dearth of information in Africa on the key concepts of this study.

Contribution of Anthropogenic Factors and Climate Variables to Human Cystic Echinococcosis Mortality in Chile (2001-2011).

Here we assess the effect of weather and anthropogenic environmental variables, particularly urbanization, on cystic echinococcosis mortality in Chile from 2001 to 2011 using a nonparametric regression model, multivariate adaptive regression splines, and Poisson nonlinear regression models. This study integrated data from various sources on weather and anthropogenic variables. The canine population had the greatest influence on human cystic echinococcosis mortality during the period analyzed. Urbanization among anthropogenic variables and temperature and precipitation among the weather-related variables were the main factors related to cystic echinococcosis deaths. Deaths decreased with urbanization level. Temperature showed a nonlinear impact on mortality, with an optimum value ∼11°C. Public policies aimed at improving safe management of companion animal populations are crucial in controlling the spread of this disease. Effective animal management strategies would have wide-ranging public health benefits, advance the welfare of companion animals and livestock, and decrease the number of human cystic echinococcosis cases.

Selected wetland soil properties correlate to Rift Valley fever livestock mortalities reported in 2009-10 in central South Africa.

Outbreaks of Rift Valley fever have devastating impacts on ruminants, humans, as well as on regional and national economies. Although numerous studies on the impact and outbreak of Rift Valley fever exist, relatively little is known about the role of environmental factors, especially soil, on the aestivation of the virus. This study thus selected 22 sites for study in central South Africa, known to be the recurrent epicenter of widespread Rift Valley fever outbreaks in Southern Africa. Soils were described, sampled and analyzed in detail at each site. Of all the soil variables analyzed for, only eight (cation exchange capacity, exchangeable Ca2+, exchangeable K+, exchangeable Mg2+, soluble Ca2+, medium sand, As, and Br) were statistically identified to be potential indicators of sites with reported Rift Valley fever mortalities, as reported for the 2009-2010 Rift Valley fever outbreak. Four soil characteristics (exchangeable K+, exchangeable Mg2+, medium sand, and Br) were subsequently included in a discriminant function that could potentially be used to predict sites that had reported Rift Valley fever-associated mortalities in livestock. This study therefore constitutes an initial attempt to predict sites prone to Rift Valley fever livestock mortality from soil properties and thus serves as a basis for broader research on the interaction between soil, mosquitoes and Rift Valley fever virus. Future research should include other environmental components such as vegetation, climate, and water properties as well as correlating soil properties with floodwater Aedes spp. abundance and Rift Valley fever virus prevalence.

Case fatality rate and risk factors for Nipah virus encephalitis: A systematic review and meta-analysis.

BACKGROUND: A wide range of Nipah virus (NiV) encephalitis case fatality rates (CFR) have been reported. Data on the involvement of several potential risk factors in Nipah virus transmission remain controversial. We performed a systematic review and meta-analysis to estimate the pooled CFR of NiV encephalitis and to assess the risk factors for NiV infection. METHODS: Articles published up to the 27thof November 2018 in MedLine, Embase and Web of knowledge databases were considered for this study. We included cross-sectional, cohort, and case-control studies that have reported NiV CFR and/or risk factors. Data were pooled with random-effects model. This review was registered in the PROSPERO, CRD42018116242. FINDINGS: This global review included 22 citations (25 studies) including 2156, 1682, and 474 suspected, probable, and confirmed cases of NiV encephalitis, respectively. We determined a pooled CFR for NiV encephalitis at 61.0% (95% CI, 45.7-75.4; I² = 96.8%). Climbing trees (OR = 1.4; 95% CI; 1.0-1.9), male gender (OR = 1.5; 95% CI; 1.1-2.0), travel outside their own sub-district (OR = 2.0; 95% CI; 1.4-2.9), and exposure to date palm sap (DPS) (OR = 5.7; 95% CI; 3.8-8.6) or pigs (OR = 7.6; 95% CI; 1.2-45.4) were significantly associated with NiV infection. CONCLUSION: Findings from this study suggest that NiV Encephalitis is associated with a high CFR and that male gender, travel outside their sub-district, climbing trees, and exposure to pigs and DPS are associated with an increased risk of NiV encephalitis.

[Hospitalizations and deaths related to sporotrichosis in Brazil (1992-2015)]. / Hospitalizações e óbitos relacionados à esporotricose no Brasil (1992-2015).

Sporotrichosis is a subcutaneous mycosis with global distribution, and patients generally receive outpatient treatment. Since 1998 there has been an increase in cases in the state of Rio de Janeiro, Brazil, mainly via zoonotic transmission involving cats. Patients coinfected with the human immunodeficiency virus (HIV) often require hospitalization and evolve to death. This study analyzes and describes data from 1992 to 2015 obtained from the database of the Brazilian Unified National Health System (SUS). There were 782 hospitalizations and 65 deaths in Brazil. Six percent of the hospitalizations and 40% of the deaths involved coinfection with HIV. There were 250 hospitalizations and 36 deaths in Rio de Janeiro, with a progressive increase over the course of the period. The states of São Paulo and Goiás also showed high numbers. Men, non-whites, and individuals with low schooling evolved more frequently to death. In conclusion, sporotrichosis is associated with hospitalizations and deaths throughout Brazil, especially in the state of Rio de Janeiro.

A esporotricose é uma micose subcutânea de distribuição global e, em geral, os pacientes são tratados ambulatorialmente. Desde 1998, observa-se aumento dos casos no Estado do Rio de Janeiro, Brasil, especialmente por transmissão zoonótica envolvendo gatos. Os pacientes coinfectados pelo vírus da imunodeficiência humana (HIV), muitas vezes, necessitam de hospitalizações e evoluem a óbito. Este estudo analisa e descreve dados de 1992 a 2015, provenientes de bancos de dados do Sistema Único de Saúde. No Brasil, ocorreram 782 hospitalizações e 65 óbitos. Em 6% das hospitalizações e 40% dos óbitos, havia coinfecção pelo HIV. No Rio de Janeiro, foram 250 hospitalizações e 36 óbitos, com aumento progressivo, ao longo do período. Destacaram-se, ainda, São Paulo e Goiás. Homens, não brancos, com baixa escolaridade evoluíram mais frequentemente a óbito. Conclui-se que a esporotricose está associada a hospitalizações e óbitos em todo o Brasil, com destaque para o Rio de Janeiro.

La esporotricosis es una micosis subcutánea de distribución global y, en general, los pacientes son tratados ambulatoriamente. Desde 1998, se observa un aumento de los casos en el estado de Río de Janeiro, Brasil, principalmente por transmisión zoonótica implicando gatos. Los pacientes coinfectados por el virus de la inmunodeficiencia humana (VIH), muchas veces, necesitan de hospitalizaciones y evolucionan a óbito. Este estudio analiza y describe datos de 1992 a 2015, provenientes de bancos de datos del Sistema Único de Salud (SUS). En Brasil, se produjeron 782 hospitalizaciones y 65 óbitos. En un 6% de las hospitalizaciones y 40% de los óbitos, había coinfección por el VIH. En Río de Janeiro, fueron 250 hospitalizaciones y 36 óbitos, con un aumento progresivo a lo largo del período. Se destacaron, incluso, São Paulo y Goiás. Hombres, no blancos, con baja escolaridad evolucionaron más frecuentemente a óbito. Se concluye que la esporotricosis está asociada a hospitalizaciones y óbitos en todo Brasil, destacando Río de Janeiro.