Possible Routes Of Transmission Research Articles

Antibiotics Sensitivity Reaction of salmonella Species Isolated from Ready-to-Eat Porridge Beans Sold in Federal Polytechnic of Oil and Gas Bonny of Rivers State

Salmonella specie is one of the four key global causes of diarrhoeal diseases. In this research we investigated the frequency occurrence of salmonella species isolated from ready-to-eat porridge beans sold from vendors in the proximity of federal polytechnic of oil and gas bonny island. A total of 40 samples were purchased from four different food vendors in four different spots [vendor 1(The first spot), vendor 11(second spot), vendor 111(third spot) and vendor 1V (fourth spot)] between February and May 2024.All samples were processed and analysed using standard culturebased, biochemical methods and antibiotic susceptibility test assays to confirm salmonella isolates. The highest total occurrence of heterotrophic bacteria population densities were: vendor1 4.0.0×105CFU/g; vendor11 4.4×107CFU/g, vendor111 4.5×102CFU/g and vendor 1V 4.2×109CFU/g. The highest total occurrence of salmonella population density were, for vendor1 3.9×102, Vendor11 2.7×104 , Vendor111 4.1×105,Vendor1V 4.4×103 respectively. Antibiotics susceptibility test was performed for the isolates which exhibited that all of them were susceptible to Ciprofloxacin (CPR)-5 g, Nitrofurantoin (NIT)-30 g, Oflotaxin (OFL)-5 g, were susceptible to Salmonella species. While Gentamicin (GEN)-10 g, and Cefuroxime (CXM)-5 g, were intermediate and Finally, Augmentin (AUG)-30 g, Cefuroxime (CAZ)-30 g, and Cefuroxime (CRX)-30 g were resistant to Salmonella species. Therefore, it can be stated that ready-to-eat porridge beans sold in the proximity of FPOG environment are possible route of transmission for Salmonella species. However, due to lack of intense antibiotic resistance among these bacteria, most of them can be treated with the antibiotics available in the market. Nonetheless, strict monitoring and regular surveillance is necessary.

Stenotrophomonas maltophilia Outbreak in an ICU: Investigation of Possible Routes of Transmission and Implementation of Infection Control Measures.

Stenotrophomonas maltophilia, a non-fermentative, ubiquitous, gram-negative aerobic bacterium, is associated with high mortality rates, particularly in immunocompromised or debilitated patients. The prevalence rate of ICU-acquired pneumonia episodes caused by this microorganism has been found to be 2%. S. maltophilia has been identified as one of the top 10 microorganisms responsible for such infections in EU/EEA countries. This study describes an outbreak of S. maltophilia in an intensive care unit of a hospital in northern Italy. This includes an epidemiological investigation of the cases, the environmental microbiological controls carried out, a comparison of the strains by multilocus sequence typing (MLST), and the measures taken to prevent and control the outbreak. Among the seven clinical isolates of S. maltophilia analyzed herein, six demonstrated susceptibilities to trimethoprim-sulfamethoxazole. Conversely, one isolate of S. maltophilia exhibited resistance to first-line antibiotics. ST was found to be identical for six patients (ST 4), as well as in the environmental feedback on the trolley of Box 2. The analysis of the temporal and spatial progression of the outbreak has suggested that the transmission of S. maltophilia may have occurred through cross-transmission during care practices.

About the nutrition of Cleroclytus semirufus Kraatz, 1884 (Coleoptera, Cerambycidae) with the exudate of the Fire blight of fruit crops

For the first time, of the xylophage pest the longhorn beetle, Cleroclytus semirufus Kraatz, 1884 is noted to feed on the exudate of the bacterium Erwinia amylovora (Burrill, 1882) Winslow et al., 1920, the causative agent of a dangerous quarantine disease - fire blight of fruit crops. Feeding cases of beetles on the bacterial exudate of E. amylovora accounted for 36% of the total number of observations on the feeding of adults of this species. Possible routes of transmission of E. amylovora by longhorn beetles C. semirufus are considered. Infestation by larvae of C. semirufus was noted to a greater extent on apple trees infected with fire blight of fruit crops (77% of the total number of examined trees), since females of longhorn beetles prefer trees weakened for various reasons for laying eggs. Beetles C. semirufus, by transferring the fire blight of fruit crops to healthy trees, and thereby weakening them, form more favorable conditions for his reproduction. In turn, adults emerging from infested trees also transmit E. amylovora by carrying spores on the body, or by feeding on exudate, or both. That is, a typical infectious disease system "Donor-vector-recipient" is formed. The longhorn beetles is widely distributed in the zone of intensive fruit growing in Kazakhstan (in the South and South-East), and is a wide polyphage capable of transferring E. amylovora not only to the apple tree, but also to other fruit trees. Therefore, further study and monitoring of the population of this and other stem pests as a vector of fire blight of fruit crops is required. In addition, measures to control their numbers are not sufficiently developed.

Pastern dermatitis outbreak associated with toxigenic and non-toxigenic Corynebacterium diphtheriae and non-toxigenic Corynebacterium ulcerans at a horse stable in Finland, 2021.

Corynebacterium diphtheriae and Corynebacterium ulcerans, when producing toxin, are the cause of diphtheria, a potentially life-threatening illness in humans. Horses (Equus ferus caballus) are known to be susceptible to infection that may manifest clinically on rare occasions. In late 2021 and early 2022, specimens from five horses suffering from pastern dermatitis were cultured at the Laboratory of Clinical Microbiology at the Faculty of Veterinary Medicine, University of Helsinki, Finland. C. diphtheriae and/or C. ulcerans were recovered from all of these. This study aimed to (1) analyse the bacterial isolates and (2) describe the outbreak and identify possible sources of the infection and infection routes in the stable. Susceptibility testing, PCR for the tox gene, and Elek test for toxin production in PCR-positive isolates were performed. Whole genome sequencing was also conducted to achieve high-resolution strain typing. An epidemiological survey was done by means of a semi-structured interview of horses' caretaker, and contact tracing was done among people at the stable. Two tox gene-positive, toxin-producing C. diphtheriae belonged to sequence type (ST) 822. Other C. diphtheriae (n = 2, ST828) and C. ulcerans (n = 2, ST325 and ST838) isolates did not carry the tox gene. The epidemiological investigation explored numerous possible routes of transmission, but the definite source of infection was not identified. All established human contacts tested negative for diphtheriae. All horses recovered after antimicrobial treatment. Our study shows that C. diphtheriae and C. ulcerans may readily spread among horses at the same stable and complicate pastern dermatitis infections. These potentially zoonotic bacteria can cause outbreaks even in a country with a very low prevalence. Caretakers should be encouraged to wear gloves and practice good hand hygiene when treating infected skin lesions in horses.

Detection and genomic characterization of a multidrug-resistant Salmonella Newport co-harbouring blaCMY-2, qnrB19 and mcr-9 from the diarrheic faeces of a foal

ObjectivesThis study reports the genomic characterization of the multidrug resistant Salmonella Newport strain 195_20 recovered from the diarrheic faeces of a foal in Brazil and co-harbouring the mcr-9, blaCMY-2 and qnrB19 antibiotic resistance genes. MethodsBacterial isolate positive for mobile colistin resistance gene (mcr-9) was submitted to antimicrobial susceptibility testing by disk diffusion and broth microdilution for colistin and polymyxin B. The isolate was submitted to whole genome sequencing by Illumina technology and Nanopore Sequencing. Conjugation assays, plasmid sizes determined by S1-PFGE and plasmid content were investigated by hybrid assembly after MinIon long reads sequencing. ResultsIsolate 195_20 was identified as sequence type ST45, resistant to penicillin and cephalosporins (ampicillin, ceftazidime, ceftriaxone and cefotaxime), aminoglycosides (streptomycin and gentamicin), phenicol (chloramphenicol), quinolones and fluoroquinolones (nalidixic acid, ciprofloxacin, and pefloxacin), folate pathway antagonists (sulfonamides and trimethoprim-sulfamethoxazole), and tetracycline. A transferable IncHI2/IncHI2A plasmid sized ca. 262kb was found to carry the mcr-9 gene in a module consisting of IS903-mcr-9-wbuC-IS26. In addition, an 174kb IncC and a 48kb IncN plasmid were also identified in the 195_20 isolate, carrying blaCMY-2 and qnrB19, respectively. ConclusionsNot surprisingly, isolate 195_20 was susceptible to polymyxins, possibly due to absence of qseBC regulatory operon. Presence of mobile colistin resistance (mcr-9), third-generation cephalosporins (blaCMY-2) and quinolone (qnrB19) resistance determinants in zoonotic pathogens from animals in close contact with humans alerts for the possible route of transmission between these different reservoirs.

Transmission of β-lactamases in the pork food chain: A public health concern

Antimicrobial resistance (AMR) is a risk for public health that requires management in a One Health perspective, including humans, animals, and the environment. The food production chain has been identified as a possible route of transmission of AMR bacteria to humans. The most critical issue regards resistance to the Critically Important Antimicrobials (CIAs), such as β-lactams antibiotics. Here, pigs were analysed along the entire food producing chain, including feces, carcasses and pork products (fresh meat, fermented and seasoned products) ensuring treaciability of all samples.Escherichia coli were isolated and their ability to produce ESBL and AmpC β-lactamases was evaluated both phenotypically and genotypically. Strains with the same AMR profile from feces, carcasses, and meat products were selected for phylogenetic and comparative genomic analyses to evaluate the possible “farm-to-fork” transmission of β-lactams resistant bacteria. Results showed that the percentage of ESBL strains in fecal E. coli was approximately 7% and increased slightly in the pork food chain: the 10% of ESBL E. coli isolated from carcasses and the 12.5% of isolates from fresh meat products. AmpC E. coli were found only in feces, carcasses, and fresh meat with a low prevalence.Results showed that of the 243 pigs followed along the entire food chain genetic similarities in E. coli isolated from farm-to-fork were found in only one pig (feces, carcasses and fresh meat). Frequent similarities were shown in resistant E. coli isolates from carcasses and fresh meat or fermented product (three pork food chain). Moreover, in one case, bacteria isolated from fresh meat and fermented product were genotypically similar. Concluding, direct transmission of β-lactams resistance from farm-to-fork is possible but not frequent. Further studies are needed to improve risk communication to consumers and access to clear and reliable information and health concerns on food.

Investigating conspecific CsRV1 transmission in Callinectes sapidus

A reo-like virus, CsRV1, is found in blue crabs, Callinectes sapidus, from every North American location assessed, including Chesapeake Bay and the Atlantic and Gulf coasts, USA and associated with blue crabs in softshell production. CsRV1-associated crab mortality is prevalent in captive crabs, but it is still unknown how CsRV1 is transmitted. The purpose of this study was to examine the role that conspecific predation or scavenging may play in per os transmission in single exposure and repeated exposure experiments. For viruses without cell culture propagation, repeated exposure experiments have the challenge of presenting the virus consistently during the experiment and across time replicates. In a single-exposure experiment, none of the crabs fed muscle tissue of crabs carrying intense infections of CsRV1 developed CsRV1 infections. In a repeated-exposure trial, using infected muscle tissue prepared in alginate blocks, CsRV1 was detected in 11% of the crabs fed infected tissue but was not significantly different from the control group fed alginate lacking CsRV1. For repeated per os exposure experiments, the study demonstrated the utility of using alginate to present the same homogenous sample of virus, both injected and per os, over time for oral challenge experiments. Conspecific predation and scavenging could be a transmission route, but future work into this and other possible routes of transmission for CsRV1 is important to better understand the role this virus plays in wild crab populations and the soft-shell crab industry.

Detection of DNA of bacteria of the genus <i>Helicobacter</i> in pig meat

Helicobacters different from Helicobacter pylori, colonizing various animals, are also capable of causing gastritis, stomach ulcers and MALT – lymphomas in humans. Helicobacter suis is most often isolated among similar bacteria from the mucous membrane of the human stomach. In spite of its name this microorganism can also infect cats and dogs. At the same time the spread of Helicobacter suis among the pig population in different countries varies between 10.8-90.0% but in most studies it is in average 60%. It is obvious that such extensive spread of Helicobacter suis and close contacts with infected animals can contribute to occupational infections of human beings. In addition, the consumption of infected and insufficiently heat-treated pork meat is a possible route of transmission of this microorganism. In our studies on the presence of Helicobacter suis DNA in various parts of pig carcasses immediately after slaughter determined that DNA samples in 26.7% of bacterial were found on the oral mucosa, 13.3% – along the neck lines section, 6.6% - thoracic section and 0% – hock section. According to the available literature the isolation of Helicobacter suis by the bacteriological method presents great difficulties and the detection of nucleic acids of the microorganism remains as one of the few available diagnostic methods. To detect the DNA of living Helicobacter suis in pork we used the protocol for processing pork samples with ethidium monoazide in combination with PCR to study pig meat (pork neck) from various manufacturers purchased on the shelves of Kazan markets. As a result, the DNA of living Helicobacter suis was found in 0.5% of the samples.

The Pork Food Chain as a Route of Transmission of Antimicrobial Resistant Escherichia coli: A Farm-to-Fork Perspective

Antimicrobial resistance (AMR) is a public health risk that needs to be faced from a One Health perspective that includes humans, animals, and environmental health. The food production chain has been identified as a possible route of transmission of AMR bacteria to humans. The most critical phenomenon is related to Critically Important Antimicrobial (CIA) resistance. β-lactams antibiotics (cephalosporin of 3rd, 4th generation, carbapenem, monobactams, and penicillins), quinolones, aminoglycosides, polymyxin, and glycylcyclines were the CIAs chosen in this study. Samples derived from all the stages of the pork food production chain were collected, including pig feces, carcasses, and pork food products (fresh meat, fermented, and seasoned). Escherichia coli were isolated, and AMR and MDR profiles were evaluated. Enterobacterial Repetitive Intragenic Consensus (ERIC-PCR) was used to evaluate phylogenetic similarities. Data showed that 50% of phenotypical AMR observed in the entire pork food chain were related phylogenetically. The contamination of fresh meat, in half of the cases, was not directly related to contamination from feces or carcasses. Despite this, some similarities were found between feces and carcasses. In group analysis, phylogenetic similarities were detected in a 3/36 cluster (8.3%). Nevertheless, further studies are needed to improve consumer risk communication and access to clear and reliable information and health concerns on food labels.

A case of occupational transmission of mpox.

Between May 2022 and January 2023, a global mpox outbreak affected more than 84,000 patients across all continents. Transmission of mpox occurs through large respiratory droplets and direct contact with skin lesions. We present the case of a 31-year-old previously healthy male with mpox-Infection following occupational exposure to mpox from a needle stick injury with a sterile needle through a contaminated glove. The patient presented with a three-day history of fever, malaise, and an increasing erythema and swelling of one fingertip. The patient works as a medical doctor with regular exposure to patients infected with mpox. Mpox-PCR from a swab of the lesion and an oro-pharyngeal swab were positive. The lesion on his finger evolved into a necrotic skin lesion finally healing, leaving a scar. He did not develop any secondary pox on his skin and recovered fully. Only a minority of patients with mpox infection develop illness with pronounced local complications as in this case. Mpox can potentially be transmitted in an occupational context. Medical personnel should be informed about this possible route of transmission.

First detection of Blastocystis sp. in migratory whooper swans (Cygnus cygnus) in China

Blastocystis is a usual intestinal protist that always found in humans and various animals. Currently, the prevalence of Blastocystis in the migratory whooper swan (Cygnus cygnus) is unknown. In our research, we aimed to determine the occurrence, prevalence, subtype distribution and dynamic transmission mechanisms of Blastocystis in the migratory whooper swan in China. We also assessed the zoonotic potential of Blastocystis isolates, as well as possible routes of transmission and impact of this organism on One Health perspective. Fecal samples (n = 770) were collected from whooper swans inhabiting the Sanmenxia Swan Lake National Urban Wetland Park, China. The overall prevalence of Blastocystis was 11.6% (89/770). We identified 9 subtypes of Blastocystis sp., including 5 zoonotic subtypes [ST1 (Cakir et al., 2019 (8)), ST4 (Selma and Karanis, 2011 (4)), ST5 (Stensvold et al., 2009 (1)), ST6 (Fare et al., 2019 (5)) and ST7(58)] and 3 host-specific subtypes [ST10 (Zhao et al., 2018 (7)), ST14 (Tan et al., 2010 (2)), ST23 (Wang et al., 2018 (3)), and ST25 (Stensvold et al., 2009 (1))]. Subtypes ST4, ST5, ST6, ST10, ST14, ST23, and ST25 were first identified in the whooper swan. Among these subtypes, ST23 and ST25 were identified in birds for the first time, indicating that these subtypes are expanding their host range. So far, this is the first research reporting on the prevalence and subtypes distribution of Blastocystis in the migratory whooper swan in China. The findings obtained in this study will provide new insights into the genetic diversity and transmission routes of Blastocystis, and the possible public health concerns posed by this organism.

COVID-19 surveillance in wastewater: An epidemiological tool for the monitoring of SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic has prompted a lot of questions globally regarding the range of information about the virus's possible routes of transmission, diagnostics, and therapeutic tools. Worldwide studies have pointed out the importance of monitoring and early surveillance techniques based on the identification of viral RNA in wastewater. These studies indicated the presence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in human feces, which is shed via excreta including mucus, feces, saliva, and sputum. Subsequently, they get dumped into wastewater, and their presence in wastewater provides a possibility of using it as a tool to help prevent and eradicate the virus. Its monitoring is still done in many regions worldwide and serves as an early "warning signal"; however, a lot of limitations of wastewater surveillance have also been identified.

Vaccination Approach Toward Monkeypox: An Urgent Call

Vaccination Approach Toward Monkeypox: An Urgent Call

Prolonged viral shedding in feces of children with COVID-19: a systematic review and synthesis of data

During the coronavirus disease 2019 (COVID-19) epidemic, many reports have indicated that children shed the virus longer than adults in stool, and that most of the children had mild or even asymptomatic infections, which increased the potential risk for feces to be a source of contamination and may play an important role in the spread of the virus. In this review, we collected relevant literature to summarize the duration of fecal viral shedding in children with COVID-19. We found that in about 60% of the cases, the fecal shedding time was between 28 and 42 days, which was much longer than that of adults. We further explored the possible reason for prolonged shedding and its the potential impact. The poor hand hygiene practices of children, their tendency to swallow sputum and/or saliva, the significant difference in expression of angiotensin-converting enzyme 2 (ACE2) in intestine between children and adults, and the variance in immune status and intestinal microbiome could be considered as potential casual agents of longer fecal viral shedding duration of children. Conclusion: Children with COVID-19 show prolonged fecal shedding compared to adults. Several mechanisms may be involved in the longer fecal viral shedding. Viral shedding in the stool could be contributing to a possible route of transmission. Therefore, we think that further preventive measures in children should be taken to reduce the spread of the disease. What is Known:• Children with COVID-19 are more likely to have asymptomatic infections and to experience mild symptoms.• Some patients continue to shed the virus in feces, despite respiratory samples testing negative.What is New:• Children with COVID-19 carried a longer-term fecal viral shedding than adults.• The poor hand hygiene practices of children, their tendency to swallow sputum and/or saliva, the difference in expression of ACE2 in intestine between children and adults, and the variance in immune status and intestinal microbiome could be considered as potential casual agents of longer fecal viral shedding duration of children.

Sero-epidemiology and Risk Assessment of Hepatitis E Virus Among Blood Donors in North Lebanon

Background: Hepatitis E virus (HEV) is the causative agent of over 50% of acute viral hepatitis cases. The blood transfusion route has emerged as a possible route of transmission of HEV. Objectives: This study aimed to determine the seroprevalence of IgM and IgG anti-HEV among blood donors in North Lebanon and to assess the risk factors associated with its occurrence. Methods: A cross-sectional study was conducted from November to December 2020. Blood samples were collected from 78 healthy blood donors. A standardized questionnaire containing sociodemographic, food consumption, lifestyle, and health-related characteristics, was filled out to assess the risk factors of HEV exposure. Serum samples were tested for IgM and IgG anti-HEV by an enzyme-linked immunosorbent assay (ELISA). Results: The seroprevalence of IgM and IgG anti-HEV antibodies was reported in our study, and it reached 1.09% (1/78) and 12.82% (10/78), respectively. The use of private wells as a drinking source and the travel history to endemic countries have been identified as risk factors for HEV infections (P

Update on COVID-19 and Effectiveness of a Vaccination Campaign in a Global Context.

The COVID-19 pandemic caused by SARS-CoV-2 remains a significant issue for global health, the economy, and society. When SARS-CoV-2 began to spread, the most recent serious infectious disease of this century around the world, with its high morbidity and mortality rates, it is understandable why such infections have generally been spread in the past, mainly from international travel movements. This perspective review aimed to provide an update for clinicians on the recent developments related to the microbiological perspectives in pandemics, diagnostics, prevention (such as the spread of a virus), vaccination campaigns, treatment options, and health consequences for COVID-19 based on the current literature. In this way, the authors attempt to raise awareness on the transversal nature of these challenges by identifying the main risk/vulnerability factors that the scientific community must face including our current knowledge on the virus capacity of the mechanism of entry into the cells, the current classifications of viral variants, the knowledge of the mathematical model on the spread of viruses (the possible routes of transmission), and the effectiveness of vaccination campaigns in a global context of pandemic, particularly from COVID-19, with a look at new or future vaccines.

Factors Associated With Late Antiretroviral Therapy Initiation Among People Living With HIV in Southern Iran: A Historical Cohort Study.

ObjectivesLate initiation of antiretroviral therapy (ART) is associated with poor outcome among people living with HIV (PLHIV) and higher risk of transmission of infection. This study was conducted to identify the determinants of late ART initiation among PLHIV in Southern Iran.MethodsA historical cohort study was conducted on 1,326 PLHIV of ≥15 years of age who were registered with the behavioral diseases counseling center (BDCC) in southern Iran from August 1997 to March 2021. Late ART initiation was defined as a CD4 cell count <200 cells/mm3 or having a clinical AIDS diagnosis at the time of ART initiation. The required demographic and clinical data were collected from the patients' medical records. Multiple regression analysis was conducted to define late ART initiation associated factors.ResultsLate ART initiation was found among 81.9% of patients. Based on the results of the multivariate analysis, older age (odds ratio [OR] = 1.02, 95% CI = 1.00–1.04), being single (ORsingle/married = 1.80, 95% CI = 1.17–2.78), history of drug use (ORyes/no = 1.64, 95% CI = 1.02–2.62), year of ART initiation (OR2011−2013/2018−2021 = 3.65, 95% CI = 2.28–5.86), and possible route of transmission (ORdruginjection/sexual = 7.34, 95% CI = 1.16–46.21) were directly associated with the risk of late ART initiation.ConclusionsThe results show that the prevalence of late ART initiation was alarmingly high. For better infection control and better prognosis of infection, people at high risk need to be provided with timely services (e.g., diagnosis, treatment, training, and social support).

Genomic surveillance uncovers ongoing transmission of carbapenem-resistant Acinetobacter baumannii (CRAB) and identifies actionable routes of transmissions in an endemic setting.

In our center, previous infection prevention and control (IPC) resources were concentrated on multidrug-resistant organisms other than CRAB because the rate of CRAB was stable with no evidence of outbreaks. Triggered by an increase in the baseline rate of CRAB isolated in clinical cultures, we investigated horizontal transmission of CRAB to guide targeted IPC actions. We prospectively collected clinical data of patients with positive CRAB cultures. We identified genetic relatedness of CRAB isolates using whole-genome sequencing. Findings were regularly presented to the IPC committee, and follow-up actions were documented. During the study period, 66 CRAB isolates were available for WGS. Including 12 clinical isolates and 10 environmental isolates from a previous study, a total of 88 samples were subjected to WGS, of which 83 were successfully sequenced and included in the phylogenetic analysis. We identified 5 clusters involving 44 patients. Genomic transmissions were explained by spatiotemporal overlap in 12 patients and by spatial overlap only in 12 patients. The focus of transmission was deduced to be the intensive care units. One cluster was related to a retrospective environmental isolate, suggesting the environment as a possible route of transmission. Discussion of these findings at multidisciplinary IPC meetings led to implementation of measures focusing on environmental hygiene, including hydrogen peroxide vapor disinfection in addition to terminal cleaning for rooms occupied by CRAB patients. We showed that WGS could be utilized as a "tool of persuasion" by demonstrating the presence of ongoing transmission of CRAB in an endemic setting, and by identifying actionable routes of transmission for directed IPC interventions.

The role and relevance of asymptomatic healthcare worker testing in COVID-19 hospital outbreaks

Background: Many healthcare facilities have faced the decision of conducting point prevalence testing (PPT) of healthcare workers (HCW) during COVID-19 outbreaks. As a containment strategy, PPT can identify asymptomatic or presymptomatic cases for isolation. It is less clear how useful testing asymptomatic HCW is in understanding the spread and possible routes of transmission in an outbreak. This study investigated HCW cases identified through PPT during acute-care outbreaks in Fraser Health (FH), British Columbia, incorporating both epidemiological and whole-genome sequencing (WGS) data to determine their epidemiological source. Methods: This study was a retrospective review of cases associated with COVID-19 acute-care outbreaks in FH occurring between December 2020 and June 2021, when most of these infections were of the alpha and gamma lineages. All patients and HCWs with a positive COVID-19 test and epidemiologically linked to the outbreaks were included in the study. WGS results supported determination of epidemiological source for cases. The proportion of patient and HCW cases related to the outbreak was compared. All analyses were conducted using SAS version 4.3 software with the PROC GLM package. Results: Between December 2020 and June 2021, 49 acute-care COVID-19 outbreaks were declared. Point-prevalence testing of HCWs, in addition to routine patient PPT, was conducted in 28 outbreaks (57%), with 2,167 eligible HCWs (63%) tested. Testing identified 14 previously unknown HCW cases, representing 12.96% of all HCW cases epidemiologically linked to the outbreaks. None of these HCWs were determined to be the index case for their associated outbreak. There was no statistically significant difference between HCWs and patients regarding WGS failure rate, and all failed samples were removed from further analysis. Patients were 3.8 times as likely as HCWs to present as symptomatic when testing positive. HCWs were 2.2 times as likely as patients to have WGS results unrelated to the outbreak. Discussion: Although point-prevalence testing of HCW identified previously unknown cases, these cases were more likely than patients to be unrelated to the outbreak and therefore less useful in understanding the epidemiology of the outbreak. It is difficult to determine whether HCW PPT was effective at preventing transmission, especially with robust infection prevention measures already in place. Patients were more likely than HCWs to present as asymptomatic, however this may be due to the attribution of symptoms to other conditions. Conclusions: Point prevalence testing of HCWs during COVID-19 outbreaks may assist with preventing transmission but is less likely to contribute meaningful information to the investigation.Funding: NoneDisclosures: None

Evaluation of different transmission routes of Cystoisospora suis in a farm using prophylactic toltrazuril

Coccidiosis is an enteric disease caused by protozoa, especially Cystoisospora suis which can lead to large losses in production. Its transmission occurs through different routes, mainly affecting piglets in the first weeks of life and normally progressing with diarrhea unresponsive to antibiotic therapy. The objective of this work was to evaluate, in two seasons of the year, the occurrence of C. suis in piglets and sows, the transmission routes and source of infection and the influence of the preventive use of toltrazuril on these epidemiological parameters. Two experiments were carried out, the first being in winter; under the influence of prophylactic use of toltrazuril; and the second in the summer, six months after the suspension of the prophylactic use of toltrazuril. The study included 36 sows (18 controls, 18 treated toltrazuril). The following samples were collected: rest of the sows, water from the individual drinkers in each cage, organic swabs present in the keepers' shoes, environmental swabs pre and housing, present in the cages in the rooms and accumulations of the maternity cage. As were disclosed to coproparaological and PCR exams. The presence of C. bebe ocysts is the winter and summer control following samples: sow feces (2.84%) of the winter and summer control groups (7.60%) of the winter and summer treated groups and the treated group winter and summer, rectal swabs from litters (9.03%) in the control and treated groups in winter, collected from the environment (20.22%) from all groups. Like others, they were negative for the presence of the parasite. There was no difference between the control and toltrazuril groups and no positive samples were observed in the summer. The possible route of transmission of the agent in the present work was the water from the douros. Preventive therapy with toltrazuril in farms with low infection pressure is not necessary to control C. suis.