Zoonotic Diseases

Monkeypox (MPX) is a relatively unknown and minor resurgent viral zoonotic disease caused by the monkeypox virus (MPXV). The disease can spread from person to person or from animal to person. The disease is most prevalent in the tropical rainforests of West and Central Africa. The first MPXV outbreak was recorded in a monkey during 1958 as a small pox-like disease causing flu-like symptoms, such as chills and fever, as well as a rash, and the first MPXV case in a human was in a 9-month-old child in the Democratic Republic of the Congo on 1 September 1970. There were 16,016 laboratory confirmed cases of MPXV infection and five deaths reported in 75 countries/territories/areas across all six WHO Regions as of 22 July 2022. MPXV has a wide host range, including humans, squirrels, mice, rabbits, hamsters, porcupines, non-human primates (orangutans, chimps, sooty mangabeys, cynomolgus monkeys), black-tailed prairie dogs, African brush-tailed porcupines, rats, and shrews. MPXV replicates at the site of inoculation, the respiratory or oropharyngeal mucosa, and spreads to other organs, such as the skin, lungs, and gastrointestinal tract, where clinical signs and symptoms of the disease manifest. Before the rash appears, most patients have prominent lymphadenopathy, which distinguishes human MPX from small pox. This is followed by macules, papules, vesicles, pustules, umbilication, scabbing, and desquamation. Laboratory tools, such as virus isolation, PCR-based assays, haemagglutination inhibition assays, electron microscopy, ELISA, Western blotting, or immunohistochemistry, have been used to confirm diagnoses. Following a confirmatory diagnosis, tecovirimat, an FDA-approved antiviral drug, is currently available to treat severe cases of MPXV infection, along with symptomatic and supportive therapies. Physical and close contact activities, such as sleeping in the same room or on the same bed as the infected person, intimate contact with an infected partner, living in the same house as infected people, and sharing the same cups and plates, must be avoided to prevent the spread of the disease. Vaccination with vaccinia virus against monkeypox is approximately 85% effective and may protect against MPXV infection if administered within 4 days and up to 14 days (without showing any symptoms) after initial contact with a confirmed monkeypox case. Full article

The risk of acquiring hepatitis E virus (HEV) infections by wild animals living in the European wild nature has previously been reported and high anti-HEV antibody detection rates were detected in several animal species. However, data on the HEV seroprevalence of wild boars and deer held in game reserves are rare. In the present study, we investigated anti-HEV seroprevalence and HEV RNA in 38 deer and 15 wild boars living in a game reserve in Northern Germany. Surprisingly, none of the animals tested positive for HEV RNA in blood, liver, or muscle (diaphragm), and all animals (n = 53, 100%) were anti-HEV negative. In conclusion, HEV infections in enclosed areas, such as game reserves, in Germany are rare, and the risk of HEV transmission through meat from these animals to humans seems to be low. Full article

Climate change has contributed to changes in disease transmission. In particular, zoonoses such as tick-borne diseases are occurring in areas previously unsuitable for tick survival, with spread to non-endemic areas rising. Ophthalmic manifestations of tick-borne diseases are rare. Often overlooked, diagnosis requires awareness and a high level of suspicion, which may delay treatment. This review provides a comprehensive overview of ocular disease associated with ticks so that management protocols for patients can be designed and implemented. A narrative literature review was conducted. The current literature includes case series, case reports, and literature reviews. Ocular manifestations of tick-borne diseases include adnexal manifestations, conjunctivitis, keratitis, cranial nerve palsies, optic nerve disease, uveitis, exudative retinal detachment, and panophthalmitis, which may occur in isolation or as part of a systemic process. As there is no one constellation of ocular symptoms and signs diagnostic of tick-borne eye diseases, a systematic approach is recommended with particular attention to significant travel and exposure history. In this review, we identify significant risk factors and propose management strategies for afflicted patients to improve treatment outcomes while maintaining cost-effectiveness. Ophthalmologists and generalists will benefit from increased awareness of ocular manifestations of tick-borne diseases in the age of modern travel and climate change. Full article

Brucellosis is one of the most common etiologies of laboratory-acquired infections worldwide, and handling of living brucellae should be performed in a Class II biological safety cabinet. The low infecting dose, multiple portals of entry to the body, the wide variety of potentially contaminated specimens, and the unspecific clinical manifestations of human infections facilitate the unintentional transmission of brucellae to laboratory personnel. Work accidents such as spillage of culture media cause only a small minority of exposures, whereas >80% of events result from unfamiliarity with the phenotypic features of the genus, misidentification of isolates, and unsafe laboratory practices such as working on an open bench without protective goggles or gloves or the aerosolization of bacteria. The bacteriological diagnosis of brucellae by traditional methods is simple and straightforward but requires extensive manipulation of the isolates, and, nowadays, many laboratory technicians are not familiar with the genotypic features of the genus, resulting in inadvertent exposure and contagion. Detection of brucellar infections by culture-independent molecular methods is safe, but the identification of the organism using MALDI-TOF technology is not hazard-free, requiring an initial bacterial inactivation step to avoid transmission. Unfortunately, these novel and safer methods are costly and frequently unavailable in resource-limited endemic countries. Full article

A retrospective study was conducted in 2022 to determine the seroprevalence of brucellosis and its risk factors among goat and sheep herds in the Karenga district, Karamoja region, Uganda. Sera from 332 goats and 81 sheep from 20 kraals in all seven administrative units of the district were tested using the modified Rose Bengal test (mRBT). It was determined that brucellosis was present in 20% of the small ruminant herds in the Karenga district, with an overall animal level seropositivity of 3.39% (CI: 1.87–5.62%; n = 14/413). Higher seropositivity was recorded in goats (3.92%, CI: 2.1–6.6%) than sheep (1.23%, CI: 0.03–6.69%). Similarly, seropositivity was higher in females (3.95%, CI: 2.12–6.66%) than males (1.19%, CI: 0.03–6.456), and also higher in goats and sheep more than two years old (4.15%, CI: 2.09–7.31%) than those one to two years old (1.98%, CI: 0.24–6.97%) or those less than one year old (2.13%, CI: 0.05–11.29%). Only herd size was statistically significant (p < 0.05) as a risk factor for exposure to brucellosis in the Karenga district. Although the prevalence of brucellosis among goats and sheep in the Karenga district is low, there still exists a risk to the pastoralists who closely interact with the animals and also practice risky behaviours such as consumption of uncooked or unpasteurised goat milk. There is need to expand herd health messaging in Karenga to include risk communication on brucellosis and other zoonotic diseases. Full article

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has produced five variants of concern (VOC) to date. The important spike mutation ‘N501Y’ is common to Alpha, Beta, Gamma, and Omicron VOC, while the ‘P681R’ is key to Delta’s spread. We have analysed circa 10 million SARS-CoV-2 genome sequences from the world’s largest repository, ‘Global Initiative on Sharing All Influenza Data (GISAID)’, and demonstrated that these two mutations have co-occurred on the spike ‘D614G’ mutation background at least 5767 times from 12 May 2020 to 28 April 2022. In contrast, the Y501-H681 combination, which is common to Alpha and Omicron VOC, is present in circa 1.1 million entries. Over half of the 5767 co-occurrences were in France, Turkey, or US (East Coast), and the rest across 88 other countries; 36.1%, 3.9%, and 4.1% of the co-occurrences were Alpha’s Q.4, Gamma’s P.1.8, and Omicron’s BA.1.1 sub-lineages acquiring the P681R; 4.6% and 3.0% were Delta’s AY.5.7 sub-lineage and B.1.617.2 lineage acquiring the N501Y; the remaining 8.2% were in other variants. Despite the selective advantages individually conferred by N501Y and P681R, the Y501-R681 combination counterintuitively did not outcompete other variants in every instance we have examined. While this is a relief to worldwide public health efforts, in vitro and in vivo studies are urgently required in the absence of a strong in silico explanation for this phenomenon. This study demonstrates a pipeline to analyse combinations of key mutations from public domain information in a systematic manner and provide early warnings of spread. The study here demonstrates the usage of the pipeline using the key mutations N501Y, P681R, and D614G of SARS-CoV-2. Full article

Ticks and tick-borne pathogens are increasing public health threats due to emergence of novel pathogens, expanding geographic ranges of tick vectors, changing ecology of tick communities, as well as abiotic and biotic influences on tick–host–pathogen interactions. This review examines the major human-biting ixodid tick species and transmitted pathogens of North America. Topics addressed include current and projected tick geographic ranges, potential risks for introduction of tick transmitted microbes into those regions, and drivers for these events. Health care providers, public health authorities, and the general public need to be aware of existing, resurging, and emerging tick and tick-borne disease threats. Knowing which ticks and tick-borne pathogens are present is foundational to understanding and responding to these threats. Dominant tick species and pathogens remain major foci of research, while limited attention has been directed to other human-biting ticks for decades, resulting in questions about current distributions, population sizes, and diversity of infectious agents they are capable of transmitting. Significant threats due to invasive ticks are considered. Recommendations are made for establishment of a sustained North America network for surveillance of ticks, characterization of their microbiomes and viromes, and for support of tick and tick-borne disease ecology research. Full article

Japanese encephalitis (JE) is a mosquito-borne zoonotic disease that causes severe brain inflammation. The JE virus envelope protein domain III (JEV-ED3) plays a critical role in activating receptor binding and membrane fusion. This communication briefly describes, in a computational approach, how structural changes within the JEV-ED3 mutant epitopes suppress their antibody neutralization function. The simulated results demonstrate that mutant Ser40Lys acts as an antibody neutralization escape while Asp41Arg may play the role of an escape mutant. Additionally, an examination of the double mutants on JEV-ED3 suggests that these mutants may qualify as stronger neutralizing escape agents than their single variants. The structural analysis of this work helps to identify the proper antiviral target sequences and specific monoclonal antibodies for the JEV-ED3 escape mutants. Full article

Migrant and seasonal workers in the United States, among others in rural agricultural communities, may be at an elevated risk for tick-borne diseases (TBDs). This research included a survey of over 250 such workers, both women and men, in 13 locations across five eco-systems in Texas, which is generally perceived as a non-endemic state. Employing a modified Horowitz Multiple Systemic Infectious Disease Syndrome Questionnaire, a range of data was collected regarding living conditions, such as sleeping outside, along with queries about tick exposure, tick bite encounters, illnesses, and prior TBD diagnoses. Findings revealed that 67% of the respondents who scored highest on symptom severity suggestive of a TBD reported sleeping outdoors (compared to 29% of the lowest scoring), with 78% of the likely-to-highly-likely group also recalling tick-bite encounters (compared to 20% of the lowest scoring). Approximately 28% of those who reported severe symptoms also indicated previous Lyme disease diagnoses. This research serves as an initial investigation into the living conditions associated with increased risk of TBDs among vulnerable populations. It underscores the need for further assessments of TBD risk relative to vulnerable populations even in perceived non-endemic regions and highlights the paucity of actionable data as a critical public health issue. Full article

As the spread of canine leishmaniasis (CanL) is increasing throughout the world, the need for effective agents to prevent its transmission has intensified. In this case report, an intact 1.5-year-old male French bulldog was presented for treatment of severe, sudden, and constant lameness on his right hindlimb, which had started approximately four months previously and was unresponsive to routine nonsteroidal anti-inflammatory drugs. A Neem oil-based product was sprayed three times a week on the dog’s coat for about fourteen months as the only prophylactic measure against CanL. The orthopedic examination revealed grade 3–4 lameness and marked atrophy of the thigh muscles with swollen and painful right stifle joint. The radiological investigation showed polyostotic periosteal proliferation at both hindlimbs. The diagnosis of CanL was established by examination of fine-needle aspiration of lymph nodes (left prescapular, right and left popliteal) and immunofluorescence antibody testing. A leishmanicidal therapeutic protocol was prescribed. Within ten days of starting the therapy, the dog was significantly less lame, and eight months later radiographic examination revealed complete regression of the bone lesions. Some owners resort to a naturalistic approach for CanL prevention, also using products that have not been clinically evaluated. Neem oil is thought to prevent sandfly bites in dogs. Some laboratory and field studies have identified Neem oil as a possible alternative herbal drug that is repellent to sandflies. However, the clinical, laboratory, and radiographic findings clearly show that the Neem oil spray formulation used in this case report was not an effective means of CanL prevention. There is no clinical evidence in support of Neem oil-based products for the protection of dogs against CanL transmission. As Neem oil has previously been shown to be somewhat volatile, this case report suggests that even though it is a very effective repellent against sandflies, in practice, its effect on the dogs’ coat was only short-lived. Full article

The aim of this study was the examination of the genetic diversity and antimicrobial susceptibility of C. jejuni isolates obtained from dairy farms situated in Cantabria. The presence of Campylobacter jejuni was scrutinized in dairy farms situated in the Cantabria region (Atlantic coast, North of Spain). A total of 520 samples were collected from 12 dairy farms and 62 C. jejuni isolates were achieved. Sixty-one (61) of the isolates proceeded from fresh feces and only one from the stable (soil). Characterization of the isolates was conducted by Pulsed Field Gel Electrophoresis (PFGE) analysis. Antimicrobial susceptibility testing was carried out by standardized disk diffusion test. The PFGE analysis showed a high genetic diversity. From the 62 C. jejuni isolates, 27 different PFGE types were obtained with 70% similarity. The results of the antimicrobial susceptibility tests showed that 21 out of 27 strains were resistant to ciprofloxacin (78%), and 15 of them were also resistant to tetracycline (55%), whereas none of the 27 strains analyzed were resistant to erythromycin. C. jejuni was capable of surviving in livestock waste for at least 20–25 days, whereas the maximum detectable survival time on crops was of six days. This study reveals the high genetic diversity and ciprofloxacin resistance of C. jejuni in dairy cattle farms in Northern Spain, a fact that highlights the urgent need for the surveillance and control of this foodborne pathogen. Full article

In this study, two lytic bacteriophages designated as vB_CjP and vB_CcM were isolated and evaluated for their ability to combat multidrug-resistant bacteria Campylobacter jejuni and Campylobacter coli, respectively. A morphological analysis of these phages by transmission electron microscopy revealed that the vB-CjP bacteriophage had a mean head dimension of 66.6 ± 2.1 nm and a short non-contractile tail and belongs to the Podoviridae family, whereas vB_CcM had a mean head dimension of 80 ± 3.2 nm, a contractile tail, and a length calculated to be 60 ± 2.5 nm and belongs to the Myoviridae family. The results of the host range assay showed that vB_CjP could infect 5 of 10 C. jejuni isolates, whereas vB_CcM could infect 4 of 10 C. coli isolates. Both phages were thermostable and did not lose their infectivity and ability to lyse their host following exposure to 60 °C for 10 min; furthermore, phage particles were relatively stable within a pH range of 6–8. A one-step growth curve indicated that the phages produced estimated burst sizes of 110 and 120 PFU per infected cell with latent periods of 10 and 15 min, for vB-CjP and vB-CcM, respectively. The lytic activity of these phages against planktonic Campylobacter showed that these phages were able to control the growth of Campylobacter in vitro. These results suggest that these phages have a high potential for phage applications and can reduce significantly the counts of Campylobacter spp. The lytic activity of vB-CjP and vB-CcM phages at different (MOIs) against multidrug resistance Campylobacter strains was evaluated. The bacterial growth was slightly delayed by both phages, and the highest efficiency of both phages was observed when MOI = 1 was applied. Full article

Syria has experienced armed conflict since 2011, and the provision of health care has been severely compromised due to the hostilities. At the time of writing, Northwest Syria (NWS) was outside governmental control and faced the challenges of the COVID-19 outbreak. Since the emergence of this disease, several studies have looked at the dynamics of COVID-19 transmission, predicted its progression, and determined the impact of different preventive measures. While most of these studies’ settings were in stable contexts, this study investigated the progression of the COVID-19 pandemic in Northwest Syria, a conflict-affected region, for nine months (from July 2020 to March 2021) using the Suspected-Infected-Removed (SIR) model. We adjusted the SIR model to study the impact of wearing facial masks on the outbreak dynamics and progression. Based on available data and using the basic and adjusted SIR models, we estimated the value of the basic reproduction number (R0), which provides an initial prediction of disease progression. Using the basic SIR model, the estimated R0 for the first wave of SARS-CoV-2 in Northwest Syria was 2.38. The resulting figures were overestimated in comparison with the reported numbers and data on the COVID-19 pandemic. However, the results were significantly reasonable when we adjusted the model for a preventive measure (in this case, wearing face masks). Face masks, the most available preventive measure to be applied in emergency and conflict settings, remarkably affect the outbreak dynamics and may play a key role in controlling and limiting the spread of COVID-19. The novelty of the study is provided by simulating the progress of the COVID-19 outbreak in conflict settings, as it is the first study to predict the dynamics of COVID-19 disease in NWS by adjusting for face-mask-wearing as a preventive measure to explore its impact on outbreak dynamics. Full article

Previous studies have highlighted the potential role of Mycobacterium avium subspecies paratuberculosis (MAP) and human endogenous retrovirus W (HERV-W) in the pathogenesis of type 1 diabetes (T1DM) among Sardinian subjects. To better understand how antibody responses evolve during disease progression, a serological evaluation of IgG antibodies was performed in Sardinian children with T1DM collected at different time-points following the onset of the disease. It is known that anti-PI and anti-insulin (IAA) autoantibodies are the first to appear before the clinical onset of T1DM. In order to investigate the humoral responses, 69 children with T1DM were enrolled in the study, including 25 with new onset, 25 with T1DM at 1–5 years since diagnosis and 19 with T1DM at 6–12 years since diagnosis. Serum samples were tested for the presence of antibodies (Abs) against PI_46–61, three MAP epitopes (including MAP 2404c, which has a homologous sequence with PI) and two HERV-W-derived epitopes via indirect enzyme-linked immunosorbent assay (ELISA). The data obtained from the analysis showed significantly higher IgG responses against all peptides detected in the new onset group compared to longer suffering (1–5 and 6–12 years) T1DM patients, also showing a robust correlation between the proinsulin autoantibody and anti-MAP/HERV antibodies, characterized by a progressive decline the first year after onset. Taken together, these findings support the hypothesis that MAP and HERV could act as risk factors for T1DM, suggesting that they may serve as potential biomarkers of disease progression in early-stage T1DM. Full article

Recent global outbreaks of highly pathogenic avian influenza viruses (HPAIVs) of the H5N8 subtype in poultry and wild birds have raised concerns about animal and human health, particularly after its first evidence of zoonotic transmission from birds to humans. Here, we report a lethal infection with the H5N8 HPAIV in a mandarin duck that had previously demonstrated resistance to the H5N8 HPAIV infection. In addition, we revealed that the isolated virus was a genetic reassortant between the existing H5N8 HPAIV and LPAIV(s). Although further studies are warranted to assess the impact of the genetic reassortment on virus pathogenicity, the potential role of mandarin ducks in HPAIV dissemination should be re-evaluated. Full article

Phlebotomine sandflies are important vectors of Leishmania spp. and phleboviruses causing disease in animals and humans. Morphological identification of phlebotomine sandflies to the species level is challenging, requiring microscopical examination of the genitalia, which is demanding and time consuming. Molecular sandfly species identification can be a practical solution to save resources since it enables further molecular studies capable of generating data, such as biting preferences by blood meal analysis. In this study, resorting to a sandfly dataset collected between 2014 and 2018 across Portuguese territory under active mosquito surveillance and sandfly specific surveys, we used molecular methods to explore the genetic diversity and spatial distribution, further exploring ecological co-variants of four sandfly species—Phlebotomus ariasi, P. perniciosus, P. sergenti, and Sergentomyia minuta—all of which are of public health importance. Sandflies were collected from Spring to Autumn (May–November) following local temperature patterns. P. perniciosus was the most widespread detected species, with a nationwide distribution. All studied species clustered together with known samples from the Iberian Peninsula. Further monitoring studies of sandfly species diversity, distribution, and seasonality are essential for surveillance and control of sandfly-borne pathogens both nationally and globally. Full article

Hepatitis E virus (HEV) is the main cause of enterically transmitted hepatitis in humans worldwide. Among HEV, genotypes 3 and 4 are considered zoonotic agents associated with domestic pigs and wild boars, showing an increasing trend in Europe. The aim of this study is to contribute data on the prevalence of HEV in wild boars in Southwest Germany and to present a time and cost-effective two-step laboratory diagnostic approach for serological monitoring of blood samples. This method uses enzyme-linked immunosorbent assay (ELISA), followed by testing for HEV RNA by reverse transcription real-time PCR (RT-qPCR). A total of 2295 blood samples were collected in 234 municipalities in 12 counties in the period from 2016 to 2020. There was an overall seroprevalence of 10.8%, ranging from 3.6% to 17.5% per county and 7.5% to 14% per year. Retesting of these blood samples for HEV RNA revealed 15.7% viremic wild boars originating from 30 municipalities in 11 counties. Viremic wild boars were found in seven regional clusters, including 84% of the animals that tested positive for HEV. Seropositive animals <1 year of age were significantly more likely to be viremic than those >1 year. Further characterization of HEV RNA resulted in the identification of genotype 3. Altogether, serological monitoring of the blood samples, complemented by successive and targeted investigations into the presence of HEV RNA based on blood samples, provide reliable information on the seroprevalence and virus load in wild boars, which proved to be a relevant and persistent sylvatic reservoir for HEV. Full article

Rabies, a zoonotic encephalitis due to transmission of a lyssavirus, such as rabies virus (RABV), has the highest case fatality of any infectious disease. A global program for the elimination of human rabies caused by dogs is proposed for realization by 2030. Sensitive, specific, and inexpensive diagnostic tests are necessary for enhanced surveillance to detect infection, inform public health and veterinary professionals during risk assessments of exposure, and support overall programmatic goals. Multiple laboratory techniques are used to confirm a suspect case of rabies. One method for the detection of lyssavirus antigens within the brain is the direct rapid immunohistochemical test (dRIT), using light microscopy, and suitable for use under field conditions. Besides dogs, other major RABV reservoirs reside among mammalian mesocarnivores and bats. To date, use of the dRIT has been applied primarily for the diagnosis of RABV in suspect mesocarnivores. The purpose of this study was to assess the usefulness of the dRIT to the diagnosis of rabies in bats, compared to the gold-standard, the direct fluorescent antibody test (DFAT). Brains of 264 suspect bats, consisting of 21 species from Arizona and Texas, were used in the evaluation of the dRIT. The overall sensitivity of the dRIT was 100% (0.969–1.0, 95% CI) and the specificity was 94.6% (0.896–0.976, 95% CI), comparable to the DFAT. This preliminary study demonstrated the utility of the dRIT in the confirmation of RABV infection in bats. Future studies should include additional geographic, lyssavirus, and mammalian species representations for broader application during enhanced rabies surveillance, with incorporation of any potential adjustments to standard protocols, as needed. Full article