Source Of Infection Research Articles

Profile of Persons Recently Infected with HIV-1 in Belgium: New Insights to Tailor Prevention Efforts.

Despite wide availability of prevention and treatment services, including the ongoing roll-out of pre-exposure prophylaxis (PrEP), the HIV epidemic is not under control in Belgium. Hence, there is a recognized need to improve case finding and early diagnosis to curb the further spread of HIV more effectively. The objective of the present study was to improve insight into the profiles of persons recently infected with HIV-1 and on their prevention trajectory. Between May 2018 and December 2022, we selected persons diagnosed in Belgium within three months of the presumed infection date. We then analyzed information collected using a questionnaire covering topics on HIV testing, sexually transmitted infections (STIs), PrEP use, sexual behavior, partner notification and substance use. The data obtained were analyzed alongside information derived from phylogenetic cluster analysis of the viral source of infection. A total of 93 persons with a recent HIV-1 infection completed the questionnaire, the majority (74%) being MSM, 14% were heterosexual women and 12% were heterosexual men. Nearly one-third of participants engaged in sexual activity with an average of 2 to 5 casual partners around the presumed time of infection. A significant percentage reported frequent substance use during sexual activity (65%), being previously diagnosed with STI (65%) and using condoms infrequently (44%). 63% reported a testing frequency of at least one HIV test per year before being diagnosed and 46% notified their previous sex partner(s) after being diagnosed. Over 20% of respondents (including 11 MSM, 4 heterosexual men and 5 heterosexual women) reported exclusive sexual activity with their steady partner. Eight participants (9%, all MSM, 75% born outside of Belgium) reported PrEP use in the past. No significant differences in behavioral characteristics were found between persons who were part of a local transmission cluster (48%) and persons that were not part of a cluster (47%). The study results revealed that the majority of persons diagnosed early with HIV-1 infection in Belgium exhibited characteristics corresponding to a high-at-risk population and were aware of this risk, as evidenced by a high testing frequency. However, partner notification rates were low and use and awareness of PrEP limited. A notable group of persons not corresponding to the high-risk profiles was also identified. This information may help to expose missed opportunities for prevention and contribute to enhancing the implementation of future prevention measures.

Case Report : Management of Open Pyometra on the Persian Queen

Pyometra commonly occurs in female cats. There are two types of pyometra: open pyometra and closed pyometra. Open pyometra refers to purulent and bloody discharge from the vulva, while closed pyometra does not have any vaginal discharge; however, there is an enlarged abdomen from the fluid-filled uterus. A 2-year-old Persian queen with an enlargement abdomen was clinically diagnosed with open pyometra as there was vaginal discharge. Additional examination, such as ultrasonography, was also performed to establish the diagnosis. Using ultrasonography, hyperechoic imaging clearly showed in the uterine lumen of the uterus. Based on the following examinations, an ovariohysterectomy was performed to eliminate the source of infection. Anti-inflammatory and antibiotic drugs were administered post-surgery, and the patient fully recovered after one week of intensive care.

Development of immunochromatographic and homogeneous assay based on quantum dot-functionalized polystyrene nanoprobes for the qualitative and quantitative screening of respiratory viruses

Accurately differentiating respiratory diseases caused by viruses is challenging because of the similarity in their early or clinical symptoms. Moreover, different infection sources require different treatments. However, the current diagnostic methods have limited differentiating efficiency and sensitivity. We developed a dual-system immunosensor with a bilayer fluorescent label as a signal amplifier for the on-site, sensitive, and accurate identification of multiple respiratory viruses (RVs). The nanomaterial, comprising a polystyrene (PS) nanosphere core encapsulated by two layers of CdSe@ZnS-COOH quantum dots (QDs), outperforms the conventional color and fluorescent labels in RV detection. The dual-system detection platform, comprising a PS@DQD-based lateral flow immunoassay (LFIA) and a PS@DQD-based homogeneous sensor, enables qualitative and quantitative screening of multiple respiratory viruses within 10 and 30 min, respectively, depending on the specific detection requirements for different application scenarios. This remarkable method provides 51.2 to 1000 times sensitivity improvement over commercial antigen detection kits and greater than 12.5 to 100 times improvement over QD-based immunosensors. Furthermore, we comprehensively evaluated the specificity, reproducibility, and stability of the integrated dual-system detection platform, demonstrating its reliability. Remarkably, the respiratory viral testing was validated using biological samples, thus illustrating its promise and convenience in the detection of respiratory viruses.

Assessment of Racial, Ethnic, and Sex-Based Disparities in Time-to-Antibiotics and Sepsis Outcomes in a Large Multihospital Cohort.

To characterize associations between race/ethnicity/sex, time-to-antibiotics, and mortality in patients with suspected sepsis or septic shock. Retrospective cohort study, with race/ethnicity/sex as the exposure, and time-to-antibiotics (relative to emergency department arrival) and in-hospital mortality as the outcome. Five Massachusetts hospitals. Forty-nine thousand six hundred nine adults admitted 2015-2022 with suspected sepsis or septic shock (blood cultures drawn and IV antibiotics administered within 24 hr of arrival, plus evidence of organ dysfunction for sepsis, and hypotension or lactate ≥ 4.0 mmol/L for septic shock). None. Among included patients, 22,598 (46%) were women, 36,626 (75%) were White, and 4,483 (9.2%) were Black. Women had longer median time-to-antibiotics than men when presenting with either suspected sepsis (203 vs. 190 min) or septic shock (160 vs. 142 min). Differences in time-to-antibiotics for women vs. men persisted after adjusting for age, race, comorbidities, source of infection, and severity of illness (adjusted odds ratio [aOR] for 3-6 vs. < 3 hr; 1.16 [95% CI, 1.07-1.25] for sepsis and aOR, 1.09 [95% CI, 1.01-1.18] for septic shock). Median time-to-antibiotics was also longer for Black vs. White patients for both sepsis (215 vs. 194 min; aOR for 3-6 vs. < 3 hr; 1.24 [95% CI, 1.06-1.45]) and septic shock (median 159 vs. 148 min; aOR, 1.32 [95% CI, 1.12-1.55]). There was no association between race/ethnicity/sex and in-hospital mortality for sepsis without shock; however, women with septic shock had higher mortality (aOR, 1.16; 95% CI, 1.04-1.29) vs. men. Higher mortality for women with septic shock persisted when also adjusting for time-to-antibiotics (aOR, 1.16; 95% CI, 1.03-1.32). In a large cohort of patients with sepsis, time-to-antibiotics was longer for both women and Black patients even after detailed risk-adjustment. Women with septic shock had higher adjusted in-hospital mortality than men, but this association was not moderated by time-to-antibiotics.

Biofilm formation of methicillin resistant Staphylococcus aureus on hospital environmental surfaces as potential sources of infection among hospitalized patients

Biofilm formation of methicillin resistant Staphylococcus aureus on hospital environmental surfaces as potential sources of infection among hospitalized patients

Infiltrative Optic Neuropathy

Infiltrative optic neuropathies represent a subset of optic nerve disorders characterized by the infiltration of cells derived from inflammatory, infectious, or tumor metastasis sources. These conditions pose significant challenges in terms of diagnosis, management, and prognosis due to their diverse clinical presentations and potential for rapid progression. Detailed ophthalmic examinations such as visual field testing and optical coherence tomography (OCT) are necessary to provide valuable insights into the structure and function of the optic nerve. Additionally, brain and orbital magnetic resonance imaging (MRI) are essential for detecting infiltrative lesions and assessing the extent of optic nerve involvement.

Outbreaks in the Neonatal Intensive Care Unit: Description and Management.

Healthcare settings, especially intensive care units, can provide an ideal environment for the transmission of pathogens and the onset of outbreaks. Many factors can contribute to the onset of an epidemic in a neonatal intensive care unit (NICU), including neonates' vulnerability to healthcare-associated infections, especially for those born preterm; facility design; frequent invasive procedures; and frequent contact with healthcare personnel. Outbreaks in NICUs are one of the most relevant problems because they are often caused by multidrug-resistant organisms associated with increased mortality and morbidity. The prompt identification of an outbreak, the subsequent investigation to identify the source of infection, the risk factors, the reinforcement of routine infection control measures, and the implementation of additional control measures are essential elements to contain an epidemic.

Infection prevention and control status at public hospitals and factors associated with COVID-19 infection among healthcare workers in Myanmar: A cross-sectional study

BackgroundHospitals should prepare for emerging diseases and protect healthcare workers (HCWs) from work-related infection. This study aims to assess public hospital preparedness for the coronavirus disease 2019 (COVID-19) a year after the Myanmar government began implementing COVID-19 prevention measures, and to identify factors associated with work-related COVID-19 infection among HCWs in Myanmar.MethodsIn January 2021, data were collected from 101 hospitals and 706 HCWs who had COVID-19 in Myanmar in 2020. Data from the hospitals included basic information, the status of infection prevention and control (IPC), the preparedness for COVID-19 (guidelines, checklists, fever screening, patient pathway, and training), handwashing facilities, and availability of personal protective equipment (PPE). Data of COVID-19 infected HCWs included age, occupation, workplace, severity and source of COVID-19 infection, knowledge and practice of handwashing, and working environment. Chi-square test was performed to compare the preparedness for COVID-19 among three hospital levels (primary, secondary and tertiary levels). Logistic regression analysis was performed to identify the associated factors of work-related infection of HCWs.ResultsThe total number of beds, HCWs, and COVID-19 patients in 2020 at the 101 hospitals was 12,888, 14,421, and 19,835, respectively. The availability of PPE was high in hospitals at all levels. Approximately 80% of hospitals had functional status of IPC, set up fever screening and patient pathway, and provided training on IPC and COVID-19. However, only 39.6% of hospitals had developed COVID-19 guidelines and 55.4% had developed checklists. The percentage of hospitals that prepared each measurement was lowest at the primary level. The factors associated with work-related COVID-19 among HCWs were being 30–39 years old, working as a doctor, working at isolation wards, having disinfection technique training, and having enough PPE at the workplace.ConclusionThe preparedness for COVID-19 at public hospitals in Myanmar in January 2021 was insufficient, especially in the availability of the guidelines and checklists and at primary hospitals. A support system for hospital pandemic preparedness and monitoring of IPC implementation is needed. The government should prepare for emerging diseases and provide appropriate and adequate PPE and additional training to all HCWs, especially HCWs who work for isolation wards.

Toxoplasma gondii in rodents and shrews in Armenia, Transcaucasia

Toxoplasma gondii infections in small mammals are important because they serve as source of infection for the felids who excrete environmentally resistant oocysts in their feces. Here, the authors sought evidence for T. gondii infection in shrews and rodents in Armenia for the first time. Toxoplasma gondii DNA was detected in tissues of trapped animals using a specific PCR targeting gene with a non-coding fragment length of 529 bp. Toxoplasma gondii DNA was detected in 15 out of 137 (10.9%) samples from small mammals from 6 different localities of Armenia for the first time.

Anthrax in the Russian Federation in 2023 or in other words, «the same old story»

Introduction. The current anthrax situation in Russia is characterized by instability. In 2023, there was an increase in the number of infection outbreaks compared to the long-term average (for five years). The aim of the study is to assess the epizootological and epidemiological situation regarding anthrax in the Russian Federation in 2023 and the reasons for its deterioration, and to analyze data from genomic epidemiological surveillance of this infection. Materials and methods. The information of the territorial bodies of Rospotrebnadzor on the investigation of anthrax outbreaks, reference materials about anthrax stationary hazardous areas and anthrax burials were used. The phylogenetic position of the identified Bacíllus anthracis strains and genomes structure were determined based on whole-genome sequencing data. Results. In 2023 anthrax outbreaks were registered in the Chuvash Republic — Chuvashia (1), the Tyva Republic (1), Tambov (1), Ryazan (1) and Voronezh (3) regions. 14 farm animals and 19 people fell ill. The infection of animals not vaccinated against anthrax, as well as vaccinated long before contact with the source of infection, occurred mainly during grazing in the territories of old (unregistered) anthrax soil foci. Human disease is caused by contact with sick animals during care, forced slaughter, cutting, transportation of carcasses and meat, cooking processing of contaminated meat and offal, and consumption of insufficiently heat-treated liver. 17 patients were diagnosed with a cutaneous form of anthrax, while 2 had an oropharyngeal form combined with a cutaneous form of the disease. In all cases, the genome structure typical of the B. anthracis species has been established. The phylogenetic relationship of B. anthracis isolates with B. anthracis strains previously isolated in Russia is shown. Conclusion. The reason for the trouble in anthrax in 2023 was a number of violations of veterinary and sanitary-epidemiological regulations against the background of the presence of soil foci of infection. Stabilization of the situation can be achieved only in full range of regulated preventive measures are constantly implementated. The results of molecular genetic typing of B. anthracis strains isolated during the epidemiologic investigation of seven anthrax outbreaks in the Russian Federation in 2023 allow us to conclude that they are of local origin and have a genome structure typical of the species. Genetic analysis of the isolated strains demonstrated the effectiveness of the developed wgSNP typing system in the epidemiologic investigation of outbreaks.

HEV-3 subtypes and strains detected in cases of HEV infection in central Italy from 2015 to 2023.

HEV is an emerging pathogen in Europe and was previously shown to be hyperendemic in areas of Abruzzo and Lazio, Central Italy. No systematic analysis of the HEV strains responsible for human infections over several years in Central Italy has previously been reported. Aim of the study was the molecular characterization of HEV from autochthonous hepatitis E cases occurred in Abruzzo and Lazio between 2015 and 2023. Samples from 118 cases collected as part of virological surveillance in Abruzzo and Lazio from 2015 to 2023 were subjected to HEV sequencing and phylogenetic analysis. The main observed subtype was 3f, followed by 3c and 3e. The annual subtype distribution was quite stable over the observation period, but 3f cases tended to concentrate in winter/early spring whereas 3e cases in summer. Phylogenetic clusters of highly related sequences (a) highlighted unrecognized "point source outbreaks", (b) provided molecular support to temporally and/or geographically linked cases and (c) provided evidence for transmission of identical/highly related strains up to months/years following their first detection. The data provide an overview of the HEV strains responsible for human infections over eight years in Central Italy. The observed subtype distribution appears to agree better with the subtype distribution reported in Italy in pigs rather than in geographically matched wild boars, suggesting pig and its derivate food was a more frequent source of infection than wild boar in Abruzzo and Lazio. Molecular characterization is essential to recognize "point source outbreaks" and to monitor HEV circulation.

The Spread of Mycobacterium chimaera from Heater-Cooler Units and Infection Risk in Heart Surgery: Lessons from the Global Outbreak?

Mycobacterium chimaera (MC), a member of the Mycobacterium avium complex, can cause infections in patients after open-heart surgery due to contaminated heater-cooler units (HCUs). The transmission route of HCU-related MC infection is non-inhalational, and infection can occur in patients without previously known immune deficiency. Patients may develop endocarditis of the prosthetic valve, infection of the vascular graft, and/or manifestations of disseminated mycobacterial infection (splenomegaly, arthritis, hepatitis, nephritis, myocarditis, etc.). MC infections have serious outcomes (30-50% recurrence rate, 20-67% mortality rate). In 2015, an international outbreak of M. chimaera infections among patients undergoing cardiothoracic surgeries was associated with exposure to contaminated LivaNova 3T HCUs (formerly Stöckert 3T heater-cooler system, London, United Kingdom). In response to the global outbreak, many international agencies have issued directives and recommendations in order to reduce the risk of MC infection in cardiac surgery. Whole-genome sequencing (WGS) technology can be used to describe the global spread and dynamics of MC infections, to characterize local outbreaks, and also to identify sources of infection in hospital settings. In order to minimize the risk of contamination of HCUs and reduce the risk of patient infection, it is imperative that healthcare facilities establish a program of regular cleaning and disinfection maintenance procedures as well as monitoring of the water used and the air in the operating room, in accordance with the manufacturer's procedure.

Lethal Borna disease virus 1 infections of humans and animals – in-depth molecular epidemiology and phylogeography

Borna disease virus 1 (BoDV-1) is the causative agent of Borna disease, a fatal neurologic disorder of domestic mammals and humans, resulting from spill-over infection from its natural reservoir host, the bicolored white-toothed shrew (Crocidura leucodon). The known BoDV-1-endemic area is remarkably restricted to parts of Germany, Austria, Switzerland and Liechtenstein. To gain comprehensive data on its occurrence, we analysed diagnostic material from suspected BoDV-1-induced encephalitis cases based on clinical and/or histopathological diagnosis. BoDV-1 infection was confirmed by RT-qPCR in 207 domestic mammals, 28 humans and seven wild shrews. Thereby, this study markedly raises the number of published laboratory-confirmed human BoDV-1 infections and provides a first comprehensive summary. Generation of 136 new BoDV-1 genome sequences from animals and humans facilitated an in-depth phylogeographic analysis, allowing for the definition of risk areas for zoonotic BoDV-1 transmission and facilitating the assessment of geographical infection sources. Consistent with the low mobility of its reservoir host, BoDV-1 sequences showed a remarkable geographic association, with individual phylogenetic clades occupying distinct areas. The closest genetic relatives of most human-derived BoDV-1 sequences were located at distances of less than 40 km, indicating that spill-over transmission from the natural reservoir usually occurs in the patient´s home region.

Toxoplasma gondii DNA in Tissues of Anadromous Arctic Charr, Salvelinus alpinus, Collected From Nunavik, Québec, Canada.

Toxoplasma gondii is a very common zoonotic parasite in humans and animals worldwide. Human seroprevalence is high in some regions of Canada's North and is thought to be associated with the consumption of traditionally prepared country foods, such as caribou, walrus, ringed seal and beluga. While numerous studies have reported on the prevalence of T. gondii in these animals, in the general absence of felid definitive hosts in the North there has been considerable debate regarding the source of infection, particularly in marine mammals. It has been proposed that fish could be involved in this transmission. The objectives of the present study were to perform a targeted survey to determine the prevalence of T. gondii DNA in various tissues of anadromous Arctic charr sampled in Nunavik, Québec, and to investigate the possible role of this commonly consumed fish in the transmission of infection to humans and marine mammals in Canada's North. A total of 126 individual Arctic charr were sampled from several sites in Nunavik, and various tissues were tested for the presence of T. gondii DNA using PCR. Overall, 12 out of 126 (9.5%) Arctic charr tested in the present study were PCR-positive, as confirmed by DNA sequencing. Brain tissue was most commonly found to be positive, followed by heart tissue, while none of the dorsal muscle samples tested were positive. Although the presence of T. gondii DNA in brain and heart tissues of Arctic charr is very intriguing, infection in these fish, and their possible role in the transmission of this parasite to humans and marine mammals, will need to be confirmed using mouse bioassays. Arctic charr are likely exposed to T. gondii through the ingestion of oocysts transported by surface water and ocean currents from more southerly regions where the definitive felid hosts are more abundant. If infection in Arctic charr can be confirmed, it is possible that these fish could play an important role in the transmission of toxoplasmosis to Inuit, either directly through the consumption of raw fish or indirectly through the infection of fish-eating marine mammals harvested as country foods.

Energy recovery ventilators to combat indoor airborne disease transmission: A sustainable approach

Ventilation plays a crucial role in preventing indoor airborne disease transmission. Nevertheless, ventilation increases the energy consumption of HVAC systems. Therefore, energy efficiency measures or alternative methods must be adopted to reduce the energy demand of HVAC systems, which is necessary to achieve sustainability in the building sector. This study proposes a method of utilizing an energy recovery ventilator (ERV) to provide supplementary ventilation to reduce airborne disease transmission. The proposed method is tested for an office building with one source room (with an infected occupant) and two connected rooms (no infection source). The contributions of the present study are (i) the development and verification of a new supplement ventilation method using an ERV to reduce the probability of infection from airborne pathogens and (ii) providing the economic and environmental benefits of the proposed method to promote its adaption by the building managers/HVAC engineers. The results of the present study show that the proposed method can reduce the probability of infection by 10 to 40% and demonstrate that utilizing an ERV is a sustainable and economical method to improve ventilation to reduce indoor airborne disease transmission.

Genomic approach to determine sources of neonatal Staphylococcus aureus infection from carriage in the Gambia

Staphylococcus aureus is a major cause of neonatal infections in various anatomical sites, resulting in high morbidity and mortality in The Gambia. These clinical infections are often preceded by nasal carriage of S. aureus, a known risk factor. To determine whether potential sources of newborn S. aureus infections were from carriage, and to characterize S. aureus present in different anatomical sites (blood, ear, eye, umbilical cord, skin, pus, oropharynx, breast milk and vagina), we performed whole-genome sequencing of 172 isolates from clinical sites as well as from healthy and unhealthy carriage. A random selection of mothers (n = 90) and newborns (n = 42) participating in a clinical trial and testing positive for S. aureus were considered for this study. Sequence data were analyzed to determine S. aureus multilocus sequence types and selected antimicrobial and virulence gene profiles. Our findings revealed that in The Gambia, ST15 is the dominant sequence type associated with both carriage and clinical infection. In addition, S. aureus isolates causing clinical infection among neonates were genetically similar to those colonizing their oropharynx, and the different anatomical sites were not found to be uniquely colonized by S. aureus of a single genomic profile. Furthermore, while S. aureus associated with clinical infection had similar antimicrobial resistance gene profiles to carriage isolates, only hemolysin and adhesive factor virulence genes were significantly higher among clinical isolates. In conclusion, this study confirmed S. aureus oropharyngeal colonization among neonates as a potential source of clinical infection in The Gambia. Hence, interventions aiming to reduce neonatal clinical infections in The Gambia should consider decreasing oropharyngeal S. aureus carriage.Trial registration The trial was registered at ClinicalTrials.gov NCT03199547.

Predicting Neutropenic Sepsis in Patients with Hematologic Malignancy: A Retrospective Case-Control Study.

Neutropenic sepsis (NS) is one of the leading causes of death among patients with hematologic malignancies. Identifying its predictive factors is fundamental for early detection. Few studies have evaluated the predictive factors in relation to microbial infection confirmation, which is clinically important for initiating sepsis treatment. This study aimed to determine whether selected biomarkers (i.e., body temperature, C-reactive protein, albumin, procalcitonin), treatment-related characteristics (i.e., diagnosis, duration of neutropenia, treatment modality), and infection-related characteristics (i.e., infection source, causative organisms) can predict NS in patients with hematologic malignancies. We also aimed to identify the optimal predictive cutoff points for these parameters. This retrospective case-control study used the data from a total of 163 patients (58 in the sepsis group and 105 in the non-sepsis group). We collected data with reference to the day of specimen collection, with which microbial infection was confirmed. Multiple logistic regression was used to determine predictive risk factors and the area under the curve (AUC) of the receiver operating characteristic for the optimal predictive cutoff points. The independent predictors of NS were average body temperature during a fever episode and procalcitonin level. The odds for NS rose by 9.97 times with every 1°C rise in average body temperature (95% confidence interval, CI [1.33, 75.05]) and by 2.09 times with every 1 ng/mL rise in the procalcitonin level (95% CI [1.08, 4.04]). Average body temperature (AUC = 0.77, 95% CI [0.68, 0.87]) and procalcitonin levels (AUC = 0.71, 95% CI [0.59, 0.84]) have fair accuracy for predicting NS, with the optimal cutoff points of 37.9°C and 0.55 ng/mL, respectively. This study found that average body temperature during a fever episode and procalcitonin are useful in predicting NS. Thus, nurses should carefully monitor body temperature and procalcitonin levels in patients with hematologic malignancies to detect the onset of NS.

Machine learning to attribute the source of Campylobacter infections in the United States: A retrospective analysis of national surveillance data

Integrating pathogen genomic surveillance with bioinformatics can enhance public health responses by identifying risk and guiding interventions. This study focusses on the two predominant Campylobacter species, which are commonly found in the gut of birds and mammals and often infect humans via contaminated food. Rising incidence and antimicrobial resistance (AMR) are a global concern, and there is an urgent need to quantify the main routes to human infection. During routine US national surveillance (2009-2019), 8856 Campylobacter genomes from human infections and 16,703 from possible sources were sequenced. Using machine learning and probabilistic models, we target genetic variation associated with host adaptation to attribute the source of human infections and estimate the importance of different disease reservoirs. Poultry was identified as the primary source of human infections, responsible for an estimated 68% of cases, followed by cattle (28%), and only a small contribution from wild birds (3%) and pork sources (1%). There was also evidence of an increase in multidrug resistance, particularly among isolates attributed to chickens. National surveillance and source attribution can guide policy, and our study suggests that interventions targeting poultry will yield the greatest reductions in campylobacteriosis and spread of AMR in the US. All sequence reads were uploaded and shared on NCBI's Sequence Read Archive (SRA) associated with BioProjects; PRJNA239251 (CDC / PulseNet surveillance), PRJNA287430 (FSIS surveillance), PRJNA292668 & PRJNA292664 (NARMS) and PRJNA258022 (FDA surveillance). Publicly available genomes, including reference genomes and isolates sampled worldwide from wild birds are associated with BioProject accessions: PRJNA176480, PRJNA177352, PRJNA342755, PRJNA345429, PRJNA312235, PRJNA415188, PRJNA524300, PRJNA528879, PRJNA529798, PRJNA575343, PRJNA524315 and PRJNA689604. Contiguous assemblies of all genome sequences compared are available at Mendeley data (assembled C. coli genomes doi: 10.17632/gxswjvxyh3.1; assembled C. jejuni genomes doi: 10.17632/6ngsz3dtbd.1) and individual project and accession numbers can be found in Supplementary tables S1 and S2, which also includes pubMLST identifiers for assembled genomes. Figshare (10.6084/m9.figshare.20279928). Interactive phylogenies are hosted on microreact separately for C. jejuni (https://microreact.org/project/pascoe-us-cjejuni) and C. coli (https://microreact.org/project/pascoe-us-ccoli).

Low potential of fish as a source of infection with Angiostrongylus cantonensis

Abstract Objectives Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis, cause of human eosinophilic meningitis. There is a lack of data confirming the relevance of fish in A. cantonensis life cycle and their contribution to human infection. Materials and methods We conducted a series of experiments to investigate survival and infectivity of A. cantonensis larvae in Clarias gariepinus (catfish; n=30) and Oreochromis niloticus (tilapia; n=24). Each fish was inoculated with 10,000 third-stage larvae (L3). Larval survival was assessed through artificial digestion of fish tissues one, two, and three weeks post-infection. To investigate early stages of infection, four catfish were inoculated with 10,000 L3 each and sacrificed 3 days post-infection. qPCR and histopathological examinations were performed to evaluate larval distribution and tissue reactions. Two infected catfish, sacrificed one week post-infection, were used to feed Wistar rats. Results After 45 days, the rats were not shedding L1, indicating the absence of infection. One week post-infection, dead larvae were present in digested tissues of both fish species, and the same was observed two and three weeks after exposure. qPCR analysis revealed that intestine was the most heavily infected organ. Histopathology identified dead larvae within granulomas in intestines and liver. Early-stage infection experiment showed that fish sacrificed three days post-inoculation contained viable L3 which were infective to Wistar rats. Conclusions While A. cantonensis L3 can survive and remain infective in fish for a short period, they typically die within first few days post-infection. This suggests that fish may not be significant long-term paratenic hosts for A. cantonensis but may play a temporary role in its transmission to mammals (including humans) and birds. These results are consistent with previous studies on freshwater shrimps and highlight the importance of understanding aquatic host interactions in the epidemiology of this zoonotic food-borne pathogen.

Clinical and Epidemiological Characteristics of Leptospirosis in the Gomel Region

Relevance. Leptospirosis is a zoonotic ubiquitous natural focal infectious disease that has an adverse effect on human and pet health. The territory of the Republic of Belarus in terms of its natural-climatic and soil-geographical conditions is favorable for the existence of both natural and anthropurgical foci of leptospirosis. The purpose of the work is to study the long-term dynamics of the incidence of leptospirosis in the population of the Gomel region and the clinical and epidemiological features of leptospirosis. Materials and methods. The material for the study was the data of the state statistical reporting «Report on individual infectious, parasitic diseases and their carriers» for the period from 2002 to 2022. In this work, epidemiological diagnostic methods and statistical research methods were used. Descriptive retrospective continuous study of these case histories of patients diagnosed with Leptospirosis of the Gomel Regional Infectious Diseases Clinical Hospital institution was conducted to describe clinical data. Results. In the period from 2002 to 2022, 161 cases of leptospirosis were registered in the Gomel region with an average incidence rate of 0.52 per 100 thousand population. Over this period of time, the incidence of leptospirosis was characterized by an uneven distribution and was undulating. Periods with a low incidence of 0.14–0.42 cases per 100 thousand population lasting 5-6 years alternated with periods of rising incidence to 0.99 cases per 100 thousand population lasting 3 years. In 2022, a sharp rise in the incidence of leptospirosis in the Gomel region was registered, and therefore 15.8 times higher than the incidence in 2021, the incidence rate was 1.11 per 100 thousand of the population and exceeded the national average by 4.6 times. Adults predominated among the sick (93.3%). At the same time, 73.0% of the patients were urban residents. The source of infection in 81.2% of cases were rodents, in 7.52% of cases domestic animals. In 7.52% of cases, the disease appeared as a result of professional activity, only in 3.76% of cases the disease occurred after swimming in open water. Thus, the main route of transmission of leptospirosis at present is contact (88.72%), alimentary and water are less important, respectively 7.52% and 3.76%. Results of serological examination for leptospirosis by RMA showed that 5 serogroups of leptospir circulate among rodents: L. Pomona and L. Canicola, L. Grippotyphosa, L. Icterohaemorrhagiae, L. A. Ustralis. 36.4% of the samples showed a positive result at the same time to several serogroups. L. Grippotyphosa, L. Cterohaemorrhagiae and L. Pomona were detected more often, in total, these pathogens accounted for 46.5% of positive samples. The results of the survey of farm animals showed that 60.6% of the sera studied had positive results of RMA with leptospirs of several serogroups. L. Sejroe was also isolated – in 12.3% of samples, L. Hebdomad – in 1.3% of samples, L. Icterohaemorrhagiae – in 1.2%, L. Pomona – in 0.3%, others – 24.2%. In the period from 2002 to 2021, the following serogroups were isolated in patients with leptospirosis: L. Grippotyphosa – 36%, L. Pomona and L. Canicola – 16%, L. Australi – 13%, L. Wolffi – 9%, L. Icterohaemorrhagiae – 7% and L. Tarassovi – 3%. In 2022, there is a change in the polytypage of leptospir: L. Icterohaemorrhagiae (6.7%), L. Tarassovi (6.7%), L. Wolffi (6.7%), L. Pomona (13.3), L. Astralis (13.3), L. Canicola (6.7%), 6.7% – L. Sejroe, L. Grippotyphosa Moskva – 40%. For the period from 2005 to 2022, 49 people diagnosed with leptospirosis were treated at the Gomel Regional Infectious Diseases Hospital, of which men accounted for 69%, the average age of patients was 34.5 ± 3.8 years. Most patients are hospitalized on day 6 [4 – 8] of illness. All patients complained of fever, 86% of patients had muscle pain, headaches were recorded in 56.0%, yellowing of the skin and sclera – 34.0%, abdominal pain – 38%, 25% of patients reported nausea, vomiting, diarrhea syndrome. 28.6% of patients had an icteric form of leptospirosis, Weil's syndrome was diagnosed in 9.3% of patients, hemorrhagic syndrome was observed in 18.7% of patients. All patients had laboratory confirmation of the diagnosis. The duration of hospitalization was 15 [9 – 23] days. 1 case of the disease ended with a detailed outcome for the entire observation period. Conclusion. The incidence of leptospirosis in the Gomel region is undulating and is characterized by a change in periods of rising incidence lasting up to 3 years with periods of low incidence lasting up to 5 years. The results of the study suggest that the emergence and spread of the leptospira serotype in the territory led to a new increase in the incidence. Thus, continuous qualitative monitoring of leptospira serotypes among the population of sources of infection should be carried out.