Infected Faeces Research Articles

GRIPE AVIÁRIA: CONSCIENTIZANDO A POPULAÇÃO.

Avian influenza outbreaks have already hit several countries and contact between domestic and migratory birds has been the source of many epidemic outbreaks, with high mortality rates in humans and animals. There is great concern about the spread to continents not yet affected, especially via migratory birds. Transmission occurs mainly through direct contact with infected birds, through saliva, feces, respiratory secretions and aerosols. Awareness-raising is therefore essential as a prophylactic measure. Therefore, the methodology of the work developed was a survey to analyze the population's knowledge of the disease. Based on the results, an informative video was produced and published. In this way, by being clear about the forms of transmission, the spread of avian influenza can be prevented and avoided.

Planning Policies and Public Health in Kurdistan Region of Iraq (KRI) and Its Policies to Combat COVID-19 in Duhok City

Purpose: The Kurdistan region of Iraq had been affect by the covid pandemic like the rest of the part in the world and Duhok city specifically faced several problems as the city and health policy were not ready to ace the crises. It had a negative impact on the sustainability of health sector specifically the economic side. This study tries to identify the problems to achieve tan appropriate standard of good health among Kurdistan's general population, especially in the city of Duhok, to ensure more equitable access to health services throughout the country's social and geographic expansion, take into account poverty and to strive to get better treatment, understand the condition of the city of Duhok via COVID-19, and how the government deals with the medical system in this condition, protect and encourage the right to health care for individuals and create equality in the health care system for both genders, beliefs and positions. Methodology: Through conducting the qualitative research approach by using two types for collecting data ( Data Collection Methods) which are primary data and secondary data, primary data for collecting direct information from patients and IDPs and refugees to know their health conditions and whether they are satisfied or not for public health system, physicians as well to know their treatment to patients, and secondary data to gather information from health directorate in Duhok city, camp health administration and humanitarian health organizations to understand better the situation. Findings: The findings of the study indicates that the pandemic struck at a time when public faith in the government was low, the economy was damaged by lower oil sales income, protests were common across the country, and violent extremist acts were on the rise. COVID-19 has worsened long-standing and sometimes deep-seated political, economic, social, and security issues. The COVID-19 pandemic has resulted in a dramatic loss of human life around the world, posing an unprecedented challenge to public health, food systems, and the workplace. The pandemic's economic and social impact is devastating: tens of millions of people are at risk of falling into extreme poverty, while the number of undernourished people is currently estimated to be nearly 690 million, By the end of the year, the number could have risen to 132 million. Unique Contribution to Theory, Practice and Policy: Food security, public health, and employment and labor issues, particularly worker health and safety, all intersect during the COVID-19 crisis. However, in Azadi hospital we cannot talk to people because of virus, the risk of contracting COVID-19 via an infected person's feces appears to be low. The COVID-19 virus may cause intestinal infection and be found in feces, according to some data.

Pathogenic mechanisms and etiologic aspects of Mycobacterium avium subspecies paratuberculosis as an infectious cause of cutaneous melanoma.

Infectious etiologies have previously been proposed as causes of both melanoma and non-melanoma skin cancer. This exploratory overview explains and presents the evidence for the hypothesis that a microorganism excreted in infected ruminant animal feces, Mycobacterium avium subspecies paratuberculosis (MAP), is the cause of some cases of cutaneous melanoma (CM). Occupational, residential, and recreational contact with MAP-contaminated feces, soil, sand, and natural bodies of water may confer a higher rate of CM. Included in our hypothesis are possible reasons for the differing rates and locations of CM in persons with white versus nonwhite skin, why CM develops underneath nails and in vulvar skin, why canine melanoma is an excellent model for human melanoma, and why the Bacille Calmette-Guérin (BCG) vaccine has demonstrated efficacy in the prevention and treatment of CM. The pathogenic mechanisms and etiologic aspects of MAP, as a transmittable agent underlying CM risk, are carefully deliberated in this paper. Imbalances in gut and skin bacteria, genetic risk factors, and vaccine prevention/therapy are also discussed, while acknowledging that the evidence for a causal association between MAP exposure and CM remains circumstantial.

Consistent detection of Trypanosoma brucei but not T. congolense DNA in faeces of experimentally infected cattle

Animal African trypanosomiasis (AAT) is a significant food security and economic burden in sub-Saharan Africa. Current AAT empirical and immunodiagnostic surveillance tools suffer from poor sensitivity and specificity, with blood sampling requiring animal restraint and trained personnel. Faecal sampling could increase sampling accessibility, scale, and species range. Therefore, this study assessed feasibility of detecting Trypanosoma DNA in the faeces of experimentally-infected cattle. Holstein–Friesian calves were inoculated with Trypanosoma brucei brucei AnTat 1.1 (n = 5) or T. congolense Savannah IL3000 (n = 6) in separate studies. Faecal and blood samples were collected concurrently over 10 weeks and screened using species-specific PCR and qPCR assays. T. brucei DNA was detected in 85% of post-inoculation (PI) faecal samples (n = 114/134) by qPCR and 50% by PCR between 4 and 66 days PI. However, T. congolense DNA was detected in just 3.4% (n = 5/145) of PI faecal samples by qPCR, and none by PCR. These results confirm the ability to consistently detect T. brucei DNA, but not T. congolense DNA, in infected cattle faeces. This disparity may derive from the differences in Trypanosoma species tissue distribution and/or extravasation. Therefore, whilst faeces are a promising substrate to screen for T. brucei infection, blood sampling is required to detect T. congolense in cattle.

Automatic detection of Opisthorchis viverrini egg in stool examination using convolutional-based neural networks.

Human opisthorchiasis is a dangerous infectious chronic disease distributed in many Asian areas in the water-basins of large rivers, Siberia, and Europe. The gold standard for human opisthorchiasis laboratory diagnosis is the routine examination of Opisthorchis spp. eggs under a microscope. Manual detection is laborious, time-consuming, and dependent on the microscopist's abilities and expertise. Automatic screening of Opisthorchis spp. eggs with deep learning techniques is a useful diagnostic aid. Herein, we propose a convolutional neural network (CNN) for classifying and automatically detecting O. viverrini eggs from digitized images. The image data acquisition was acquired from infected human feces and was processed using the gold standard formalin ethyl acetate concentration technique, and then captured under the microscope digital camera at 400x. Microscopic images containing artifacts and O.viverrini egg were augmented using image rotation, filtering, noising, and sharpening techniques. This augmentation increased the image dataset from 1 time to 36 times in preparation for the training and validation step. Furthermore, the overall dataset was subdivided into a training-validation and test set at an 80:20 ratio, trained with a five-fold cross-validation to test model stability. For model training, we customized a CNN for image classification. An object detection method was proposed using a patch search algorithm to detect eggs and their locations. A performance matrix was used to evaluate model efficiency after training and IoU analysis for object detection. The proposed model, initially trained on non-augmented data of artifacts (class 0) and O. viverrini eggs (class 1), showed limited performance with 50.0% accuracy, 25.0% precision, 50.0% recall, and a 33.0% F1-score. After implementing data augmentation, the model significantly improved, reaching 100% accuracy, precision, recall, and F1-score. Stability assessments using 5-fold cross-validation indicated better stability with augmented data, evidenced by an ROC-AUC metric improvement from 0.5 to 1.00. Compared to other models such as ResNet50, InceptionV3, VGG16, DenseNet121, and Xception, the proposed model, with a smaller file size of 2.7 MB, showed comparable perfect performance. In object detection, the augmented data-trained model achieved an IoU score over 0.5 in 139 out of 148 images, with an average IoU of 0.6947. This study demonstrated the successful application of CNN in classifying and automating the detection of O. viverrini eggs in human stool samples. Our CNN model's performance metrics and true positive detection rates were outstanding. This innovative application of deep learning can automate and improve diagnostic precision, speed, and efficiency, particularly in regions where O. viverrini infections are prevalent, thereby possibly improving infection sustainable control and treatment program.

P641 Faecal calprotectin determines non-response to corticosteroids in patients with immune checkpoint inhibitor colitis

Abstract Background Immune checkpoint inhibitor (ICI) therapy has improved survival outcomes in patients with advanced malignancy. ICI colitis (ICI-C) is one of the most common adverse events which often leads to cessation of an otherwise effective therapy.1,2 Corticosteroid therapy remains first-line treatment in patients with ICI-C. The aim of this study was to assess predictors of non-response to corticosteroid therapy to help guide early escalation to biologic therapy. Methods Multicentre retrospective analysis of adults hospitalized with ICI-C between July 2018 to March 2023. ICI-C was defined by patients who had current or prior immunotherapy who presented with diarrhoea with negative infective faeces PCR testing and admission diagnosis of ICI-C by their treating Physician. Baseline demographic, clinical, biochemical, and endoscopic data were collected. Grading of clinical severity on presentation and response to immunosuppression was defined by CTCAE diarrhoea grading with response defined as improvement to grade 1 or less. Results 82 patients were analysed. 31 (38%) female, median age was 65.5 years (IQR 59-72)], 27 (33%) failed corticosteroid therapy and required biologic therapy. 34 (42%) had a faecal calprotectin on admission. On univariable analysis faecal calprotectin emerged as the sole predictor of corticosteroid non-response. ROC analysis identified an optimal faecal calprotectin cut-off of 620 mcg/g to identify corticosteroid non-responders [Sensitivity 75% (57.6-92.7), Specificity 77.8% (52.4-93.6), Accuracy 76.5%, PLR 3.37 (1.36-8.38), NLR 0.32 (0.13-0.78), AUROC 0.76 (0.616-0.911), OR 10.5 (2.24-49.3), PPV 75 (47.6-92.7), NPV 77.8 ( 52.4-93.6)].12/16 (75%) of patients with a faecal calprotectin ≥ 620 required biologic therapy. Conclusion Faecal calprotectin is a predictor of non-response to corticosteroid therapy in patients with immune checkpoint inhibitor colitis. This study identified a faecal calprotectin threshold of 620mcg/g as the optimal cut-off to identify corticosteroid non-response and need for second-line immunosuppression. These findings may help to reduce the need for endoscopic assessment and guide early escalation to biologic therapy. REFERENCES: 1. Fujii T, Colen RR, Bilen MA, et al. Incidence of immune-related adverse events and its association with treatment outcomes: The MD Anderson Cancer Center experience. Invest New Drugs. 2018;36(4):638-646. doi:10.1007/s10637-017-0534-0 2. Wang Y, Abu-Sbeih H, Mao E, et al. Endoscopic and Histologic Features of Immune Checkpoint Inhibitor-Related Colitis. Inflamm Bowel Dis. 2018;24(8):1695-1705. doi:10.1093/ibd/izy104.

Evaluation of heating and liming treatments in sand samples artificially contaminated with Ancylostoma spp. eggs.

Ancylostoma spp. are found worldwide. Infected dog and cat feces can contaminate soil in public places. Despite prophylactic measures being available, studies on direct remediation of Ancylostoma-contaminated soils are scarce. This study aimed to determine the impact of heat treatment and liming on the viability of Ancylostoma spp. eggs in artificially contaminated sandy soil. Sterilized sand samples were contaminated with Ancylostoma spp. eggs extracted from infected dogs' feces. Samples were heated (trial I) to 70 °C or 80 °C, then sieved after 24 hours (212, 90, 38, and 25 µm). Larval cultures were assessed for larval development following heat treatment. Five quicklime concentrations (trial II; 50, 30, 20, 10 and 5%) were used to treat sand. The effect of liming on larval cultures was assessed by measuring embryonic development. Filariform larvae were exposed to 20% quicklime (25 °C and 37 °C, 20 min). Heat treatment destroys Ancylostoma spp. eggs and prevents in vitro larval development. Liming at 50, 30, and 20% concentrations made embryonic development impossible. However, filariform larvae treated with 20% lime solution retained their motility. Heating at 70 °C and liming at 20% were sufficient to make Ancylostoma spp. egg embryogenesis impossible in experimentally contaminated sand samples.

Responding to avian influenza A H5N1 detection on a hospital property in Maine-An interdisciplinary approach.

The risk of infection with avian influenza A viruses currently circulating in wild and domestic birds in the Americas is considered low for the general public; however, detections in humans have been reported and warning signs of increased zoonotic potential have been identified. In December 2022, two Canada geese residing on the grounds of an urban hospital in Maine tested positive for influenza A H5N1 clade 2.3.4.4b. Given the opportunity for exposure to staff and hospital visitors through potentially infected faeces on the property, public health authorities determined mitigation efforts were needed to prevent the spread of disease. The ensuing response relied on collaboration between the public health and animal health agencies to guide the hospital through efforts in preventing possible zoonotic transmission to humans. Mitigation efforts included staff communication and education, environmental cleaning and disinfection, enhanced illness surveillance among staff and patients, and exposure and source reduction. No human H5N1 cases were identified, and no additional detections in birds on the property occurred. Hospital staff identified barriers to preparedness resulting from a lack of understanding of avian influenza A viruses and transmission prevention methods, including avian influenza risk in resident wild bird populations and proper wildlife management methods. As this virus continues to circulate at the animal-human interface, this event and resulting response highlights the need for influenza A H5N1 risk awareness and guidance for facilities and groups not traditionally involved in avian influenza responses.

Anti-Cryptosporidium oocysts polyclonal antibodies for cryptosporidiosis diagnosis and protection

Cryptosporidiosis is an intestinal infection that is triggered by the protozoan parasite Cryptosporidium spp. Cryptosporidium oocysts can spread from one host to another either through direct contact with infected hosts' faeces or through indirect means (consumption of contaminated water or food). Significant numbers of oocysts are produced as a result of the rapid growth of the parasite within the infected hosts. For proper care of cryptosporidiosis, a laboratory diagnosis is necessary. Therefore, this study aimed to produce anti-Cryptosporidium parvum (C. parvum) oocyst immunoglobulin (Ig)G polyclonal antibodies (pAbs). The produced pAbs were used in the detection of C. parvum oocysts antigens in stool and serum samples of infected calves. Moreover, pAbs were tested in protection of balb-c male mice from cryptosporidiosis infection. C. parvum oocysts were used in the preparation of antigens to be used in the immunization of New Zealand white rabbits. pAb was purified by ammonium sulphate precipitation method, caprylic acid purification method and diethylaminoethyl (DEAE) anion exchange chromatographic method. Sandwich enzyme-linked immunosorbent assay (ELISA) (using prepared pAb) scored higher sensitivity (85% and 95% for serum and stool samples) than that (80%) of microscopic examination of stool samples. Moreover, pAb significantly reduced the oocysts shedding, decreased inflammatory cytokines and enhanced the loss in the body weight of protected animals. The prepared pAb succeeded in the diagnosis of cryptosporidiosis in calves with high sensitivity either in the serum or stool samples. Our results indicated the usefulness of using the prepared pAb in protection against cryptosporidiosis.

Evaluation of immunochromatography method in the diagnosis of cystic echinococcosis

Aims: Echinococcus granulosus is the causative agent of hydatid cyst, or cystic echinococcosis (CE), with its current name. Echinococcus granulosus is a zoonotic cestode; commonly found in humans and farm animals. In cystic echinococcosis infection, transmission occurs by oral ingestion of parasite eggs excreted in infected dog feces. The larval form is responsible for the formation of slowly growing cysts in the organs and tissues of mammals such as humans, sheep, goats and cattle. In this study, it was aimed to compare indirect hemagglutination (IHA) and immunochromatographic (ICT) methods from the sera of patients with suspected CE and to evaluate serological tests based on imaging and clinical diagnosis.
 Methods: Between 31 October 2022 and 31 January 2023, blood samples of 95 patients with suspected CE from different units of our hospital and for whom IHA was routinely requested were included in the study prospectively. VIRAPID® Hydatidosis (Vircell, Granada, Spain) test using the immunochromatographic method and ELI.H.A. Echinococcus (ELITech Microbio, France) test was studied in accordance with the manufacturer’s instructions.
 Results: Based on clinical and imaging methods of 95 patients included in our study, 64 (63.1%) were diagnosed with hydatid cyst. Based on imaging and clinical diagnosis; sensitivity, specificity, positive predictive value and negative predictive values were calculated as 81.3%, 96.8%, 98.1%, 71.4% for the IHA test, and were calculated as 75.0%, 93.5%, 96.6%, 64.4% for the ICT test, respectively. Good agreement was found between the two tests (percent agreement=68.0%; kappa value=0.682; p

Liver manifestations of tick-borne diseases.

Liver manifestations of tick-borne diseases.

Neospora in UK cattle

Neosporosis was first identified in the 1980s and has since become well established as an endemic disease of cattle and a significant cause of abortion. Neospora caninum is an obligate, intracellular, protozoal parasite that relies on intermediate and definitive hosts to complete its lifecycle. Neospora infection leaves cattle three to thirteen times more likely to abort than a healthy animal. Calves may be born alive but be latently infected owith Neospora or have obvious defects. Disease transmission can be horizontal, when cattle ingest feed contaminated with infected dog faeces that results in latency or exogenous transplacental infection, or vertical when latent infection recrudesces, producing a congenitally infected calf. Testing involves serology or direct testing if abortion material is available. Serology can provide a presumptive diagnosis when carried out near in time to an abortion event. Eradicating the disease involves identifying infected cows and infected family lines through serology and removing these individuals from the herd. This approach takes time because seropositive cows do not always return positive tests, and in a herd with a high seroprevalence it is not economically viable to remove large numbers of animals.

Microbiome of infected cysts, feces and saliva in patients with autosomal dominant polycystic kidney disease.

Cyst infection is a frequent and serious complication of autosomal dominant polycystic kidney disease (ADPKD). Hematogenous spread via bacterial translocation in the intestine is considered to be the main cause, so intestinal flora may be involved. However, the exact role of the intestinal flora in cyst infection in ADPKD is unknown. We report a 66-year-old woman and a 56-year-old man with ADPKD who had severe hepatic cyst infection. We analyzed the microbiome of infected cyst content, feces, and saliva in these two patients. The microbiome of patient 1 showed various bacteria in an infected cyst, whereas that of patient 2 showed only one bacterium. In both patients, the composition of the microbiome of the cyst content was quite different from those of feces and saliva, and the main bacteria in the infected cyst content represented a small proportion of those in feces and saliva. Lactobacilli were not almost detected in the infected cyst content though some lactobacilli are endemic in the gastrointestinal tract and the saliva. The association between bacteria in cysts and those in feces or saliva remains uncertain, and further research on this topic is needed.

Transposon mutagenesis of Rickettsia felis sca1 confers a distinct phenotype during flea infection.

Since its recognition in 1994 as the causative agent of human flea-borne spotted fever, Rickettsia felis, has been detected worldwide in over 40 different arthropod species. The cat flea, Ctenocephalides felis, is a well-described biological vector of R. felis. Unique to insect-borne rickettsiae, R. felis can employ multiple routes of infection including inoculation via salivary secretions and potentially infectious flea feces into the skin of vertebrate hosts. Yet, little is known of the molecular interactions governing flea infection and subsequent transmission of R. felis. While the obligate intracellular nature of rickettsiae has hampered the function of large-scale mutagenesis strategies, studies have shown the efficiency of mariner-based transposon systems in Rickettsiales. Thus, this study aimed to assess R. felis genetic mutants in a flea transmission model to elucidate genes involved in vector infection. A Himar1 transposase was used to generate R. felis transformants, in which subsequent genome sequencing revealed a transposon insertion near the 3' end of sca1. Alterations in sca1 expression resulted in unique infection phenotypes. While the R. felis sca1::tn mutant portrayed enhanced growth kinetics compared to R. felis wild-type during in vitro culture, rickettsial loads were significantly reduced during flea infection. As a consequence of decreased rickettsial loads within infected donor fleas, R. felis sca1::tn exhibited limited transmission potential. Thus, the use of a biologically relevant model provides evidence of a defective phenotype associated with R. felis sca1::tn during flea infection.

Natural reservoir Rousettus aegyptiacus bat host model of orthonairovirus infection identifies potential zoonotic spillover mechanisms

The human-pathogenic Kasokero virus (KASV; genus Orthonairovirus) has been isolated from the sera of Egyptian rousette bats (ERBs; Rousettus aegyptiacus) captured in Uganda and unengorged Ornithodoros (Reticulinasus) faini ticks collected from the rock crevices of ERB colonies in South Africa and Uganda. Although evidence suggests that KASV is maintained in an enzootic transmission cycle between O. (R.) faini ticks and ERBs with potential for incidental virus spillover to humans through the bite of an infected tick, the vertebrate reservoir status of ERBs for KASV has never been experimentally evaluated. Furthermore, the potential for bat-to-bat and bat-to-human transmission of KASV is unknown. Herein, we inoculate two groups of ERBs with KASV; one group of bats is serially sampled to assess viremia, oral, fecal, and urinary shedding and the second group of bats is serially euthanized to assess virus-tissue tropism. Throughout the study, none of the bats exhibit overt signs of clinical disease. Following the detection of high KASV loads of long duration in blood, oral, fecal, and urine specimens collected from ERBs in the serial sampling group, all bats seroconvert to KASV. ERBs from the serial euthanasia group exhibit high KASV loads indicative of virus replication in the skin at the inoculation site, spleen, and inguinal lymph node tissue, and histopathology and in situ hybridization reveal virus replication in the liver and self-limiting, KASV-induced lymphohistiocytic hepatitis. The results of this study suggest that ERBs are competent, natural vertebrate reservoir hosts for KASV that can sustain viremias of appropriate magnitude and duration to support virus maintenance through bat-tick-bat transmission cycles. Viral shedding data suggests that KASV might also be transmitted bat-to-bat and highlights the potential for KASV spillover to humans through contact with infectious oral secretions, feces, or urine.

Review of the Zoonotic Importance of Salmonellosis and Associated Risk Factors

Salmonella is one of the most common and significant human and animal food-borne pathogens that cause salmonellosis, which has high medical and monetary costs. Salmonella has a big impact on public health because it can spread zoonotic and foodborne diseases to people. Many domestic and wild animals intestinal tracts serve as the main reservoir for Salmonella, which can result in the direct or indirect contamination of a variety of foods with fecal organisms. Salmonellae are etiological agents of diarrheal and systemic infections. They can be shed in large numbers on the faces of clinical cases and carrier animals, causing contamination of the environment and frequently resulting in subclinical infections. Infection in food animals often leads to contamination of meat, eggs, milk and cheese. The organism can also spread through direct contact with infected humans, animals, or feces contaminated environments. Infected food handlers may also act as a source of contamination for foodstuffs, because of the increasing antibiotic resistance of organisms and companion animals, animals are an important source of Salmonella infection for humans. Salmonella can colonize its hosts by invading, adhering, and bypassing the host’s intestinal defense mechanisms, such as gastric acid, thanks to a variety of virulence markers and determinants, including flagella, capsule, plasmids, adhesion systems, and secretion systems. Diagnosis is based on the isolation of the organism either from tissues collected aseptically at necropsy or from faces, rectal swabs or environmental samples, food products, and feedstuffs; prior or current infection of animals by some agents may also be diagnosed serologically.

Natural Substances, Probiotics, and Synthetic Agents in the Treatment and Prevention of Honeybee Nosemosis.

Honeybees are important pollinators, but they are continuously exposed to a variety of fungal and bacterial diseases. One of the various diseases affecting honeybees is nosemosis caused by microsporidia from the Nosema genus. Honeybees are mainly infected through consumption of infected food or faeces containing Nosema spp. spores. Nosemosis causes damage to the middle intestine epithelium, which leads to food absorption disorders and honeybee malnutrition. Fumagillin, i.e., the antibiotic used to treat nosemosis, was withdrawn in 2016 from EU countries. Therefore, researchers have been looking for compounds of both natural and synthetic origin to fight nosemosis. Such compounds should not have a negative impact on bees but is expected to inhibit the disease. Natural compounds tested against nosemosis include, e.g., essential oils (EOs), plant extracts, propolis, and bacterial metabolites, while synthetic substances tested as anti-nosemosis agents are represented by porphyrins, vitamins, antibiotics, phenolic, ascorbic acids, and others. This publication presents an 18-year overview of various studies of a number of natural and synthetic compounds used in the treatment and prevention of nosemosis cited in PubMed, GoogleScholar, and CrossRef.

Reduction in SARS-CoV-2 Virus Infectivity in Human and Hamster Feces.

Objective: There is extensive evidence that SARS-CoV-2 replicates in the gastrointestinal tract. However, the infectivity of virions in feces is poorly documented. Although the primary mode of transmission is airborne, the risk of transmission from contaminated feces remains to be assessed. Design: The persistence of SARS-CoV-2 (infectivity and RNA) in human and animal feces was evaluated by virus isolation on cell culture and RT-qPCR, respectively. The exposure of golden Syrian hamsters to experimentally contaminated feces through intranasal inoculation has also been tested to assess the fecal-oral transmission route. Results: For periods that are compatible with average intestinal transit, the SARS-CoV-2 genome was noticeably stable in human and animal feces, contrary to the virus infectivity that was reduced in a time- and temperature-dependent manner. In human stools, this reduction was variable depending on the donors. Viral RNA was excreted in the feces of infected hamsters, but exposure of naïve hamsters to feces of infected animals did not lead to any productive infection. Conversely, hamsters could be experimentally infected following exposure to spiked fresh feces. Conclusion: Infection following exposure to naturally contaminated feces has been suspected but has not been established so far. The present work demonstrates that SARS-CoV-2 rapidly lost infectivity in spiked or naturally infected feces. Although the possibility of persistent viral particles in human or animal feces cannot be fully ruled out, SARS-CoV-2 transmission after exposure to contaminated feces is unlikely.

Examination of vertical transmission of Bartonella quintana in body lice following multiple infectious blood meals.

Bartonella quintana is a re-emerging louse-borne pathogen. Horizontal transmission from the body louse vector (Pediculus humanus humanus) to a human host occurs through contact with infectious louse feces containing a high concentration of the bacteria. However, questions have remained about whether vertical transmission from infected vectors to their progeny, which could significantly influence the dynamics of transmission to humans, occurs in body lice. To address this subject, we performed a series of controlled laboratory experiments that examined the presence of B. quintana on the surface of and within eggs produced by female body lice that were provisioned multiple infectious blood meals to recapitulate the natural pathogen acquisition process. Our results demonstrate that B. quintana DNA can be detected from the surface of eggs by qPCR due to vertical transfer of infectious feces to the egg sheath during or after oviposition. However, viable B. quintana could not be cultured from the hemolymph of adult female lice or from within eggs that were surface sterilized, indicating a lack of true transovarial transmission. Based on this evidence, vertical transfer of B. quintana from infected adult lice to their eggs probably has a limited impact on the dynamics of transmission to humans.

Low Prevalence of Toxoplasma gondii in Dogs From Central China.

Background Toxoplasma gondii can infect almost all warm-blooded animals, including humans and dogs. Humans can become infected with T. gondii by petting dogs that have eaten or contacted infected cat feces. The aim of this study was to evaluate T. gondii infections in dogs from central China. From 2015 to 2021, a total of 536 dog samples (195 fecal, 81 hearts, and 260 serum samples) from Henan Province were collected. Heart juice or serum samples (n = 341) were tested for T. gondii antibodies using the modified agglutination test (MAT). Fresh myocardium (n = 6) and blood (n = 2) samples were bioassayed in mice.ResultsThe present study showed that 4.40% (15/341) of the dogs were seropositive for T. gondii by MAT (cut-off, 1:25) and 4.10% (8/195) of dog feces contained T. gondii DNA. No T. gondii DNA was found in any myocardium (n = 81) or blood (n = 2) samples. The viable T. gondii strain was not isolated from any myocardium or blood samples (n = 8). Compared to the prevalence of T. gondii antibodies in dogs sampled from 2015 to 2018, the prevalence significantly declined from 2020 to 2021 (P < 0.05). Gender and age were not risk factors for dogs infected with T. gondii in this study. However, compared to other sources, dogs from Zhoukou City (close to the Yellow River) or from pet shops showed significantly higher prevalence for T. gondii (P < 0.05).ConclusionA total of 4.29% dogs were infected by T. gondii (23/536, 8 of 195 fecal samples, 2 of 260 serum, and 13 of 81 heart juice samples). This is the first survey of T. gondii infection in dog feces from China. Dogs were exposed to T. gondii, and they could act as mechanical transmitters of T. gondii.