SARS-CoV-2 viral shedding characteristics and potential evidence for the priority for faecal specimen testing in diagnosis

This study aimed to identify the specimen type that has high positivity and its proper sampling time for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing to promote diagnostic efficiency. All SARS-CoV-2-infected patients with a laboratory-confirmed diagnosis in Zhoushan City were followed up for viral shedding in respiratory tract specimens and faecal samples. Positivity was analysed both qualitatively and quantitatively by proper statistical approaches with strong testing power. Viral shedding in respiratory tract and faecal specimens was prolonged to 45 and 40 days after the last exposure, respectively. The overall positive rate in respiratory tract specimens was low and relatively unstable, being higher in the early-to-mid stage than in the mid-to-late stage of the disease course. Compared with respiratory tract specimens, faecal samples had a higher viral load, higher overall positive rate, and more stable positivity in different disease courses and varied symptomatic status. Faecal specimens have the potential ability to surpass respiratory tract specimens in virus detection. Testing of faecal specimens in diagnosis, especially for identifying asymptomatic carriers, is recommended. Simultaneously, testing respiratory tract specimens at the early-to-mid stage is better than testing at the mid-to-late stage of the disease course. A relatively small sample size was noted, and statistical approaches were used to address it. Information was missing for both specimen types at different stages of the disease course due to censored data. Our research extends the observed viral shedding in both specimen types and highlights the importance of faecal specimen testing in SARS-CoV-2 diagnosis. Healthcare workers, patients, and the general public may all benefit from our study findings. Disposal of sewage from hospitals and residential areas should be performed cautiously because the virus sheds in faeces and can last for a long time.

Multi-proxy analyses of a mid-15th century ‘Middle Iron Age’ Bantu-speaker palaeo-faecal specimen elucidates the configuration of the ‘ancestral’ sub-Saharan African intestinal microbiome

ABSTRACTThe archaeological incidence of ancient human faecal material provides a rare opportunity to explore the taxonomic composition and metabolic capacity of the ancestral human intestinal microbiome (IM). Following the recovery of a single desiccated palaeo-faecal specimen from Bushman Rock Shelter in Limpopo Province, South Africa, we applied a multi-proxy analytical protocol to the sample. Our results indicate that the distal IM of the Neolithic ‘Middle Iron Age’ (c. AD 1485) Bantu-speaking individual exhibits features indicative of a largely mixed forager-agro-pastoralist diet. Subsequent comparison with the IMs of the Tyrolean Iceman (Ötzi) and contemporary Hadza hunter-gatherers, Malawian agro-pastoralists and Italians, reveals that this IM precedes recent adaptation to ‘Western’ diets, including the consumption of coffee, tea, chocolate, citrus and soy, and the use of antibiotics, analgesics and also exposure to various toxic environmental pollutants. Our analyses reveal some of the causes and means by which current human IMs are likely to have responded to recent dietary changes, prescription medications and environmental pollutants, providing rare insight into human IM evolution following the advent of the Neolithic c. 12,000 years ago.

Evaluation of Monoclonal Antibody (IgG2bMAb) for Detection of Coproantigen from Experimentally Infected Rats with Strongyloides ratti

Background and Aim: Highly sensitive and specific diagnostic assay for the detection of Strongyloides is needed due to the intermittent and low concentration of eggs, larvae and adult worms that can be found in a faecal specimen. In some cases, repeated sampling of the faecal specimen is required to obtain satisfactory and reliable results. The aim of the study is to develop and evaluates monoclonal antibody-based Sandwich ELISA for the detection of coproantigen associated with Strongyloides infection using S. ratti as a model. Place and Duration of Study: Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, University Malaysia, Between September 2018 and March 2019. Methodology: The monoclonal antibody was raised against a soluble antigen of the infective filariform larvae (iL3) of S. ratti. The monoclonal antibody produced (IgG2bMAb) was evaluated for cross-reactivity against homologous and heterologous helminth antigens such as excretory-secretory (ES), infective larvae (iL3) and coproantigen of S. ratti, adult worms of A. caninum, A. suum, T. canis and T. cati. Results: An IgG2bMAb was observed to react with 30 kDa proteins associated with all homologous antigen from iL3, ES and coproantigen of S. ratti and cross-reacted with one heterologous antigen from adult worm of A. caninum at the same molecular weight. There was no cross-reaction observed with other heterologous antigens from adult worms of T. canis, T. cati and A. suum. The sensitivity of IgG2bMAb for the detection of S. ratti was 85% in Sandwich ELISA. Cross- reaction was observed with hookworm antigen that caused by A. caninum in Western immunoblotting. Conclusion: The results indicated that IgG2b have an immunodiagnostic property as IgG2bMAb and was able to detect antigens from coproantigen related to S. ratti with 85% sensitivity based on Sandwich ELISA) even though cross-reaction was observed with A. caninum. These findings will be very useful to tackle many cases of multiple worms’ infections such as both strongyloidiasis and hookworm. Therefore, we recommend that further evaluation and study in the human area where multiple infections can be common should be carried out.

Giardiasis in North West England: faecal specimen requesting rates by GP practice

SUMMARYMany cases of giardiasis in the UK are undiagnosed and among other things, diagnosis is dependent upon the readiness of GPs to request a specimen. The aim of this study is to assess the rate of specimens requested per GP practice in Central Lancashire, to examine the differences between GP practices and to estimate the pattern of unexplained spatial variation in the practice rate of specimens after adjustment for deprivation. To achieve this, we fitted a set of binomial and Poisson regression models, with random effects for GP practice. Our analysis suggests that there were differences in the rate of specimens by GP practices (P < 0·001) for a single year, but no difference in the proportion of positive tests per specimen submitted or in the rate of positive specimens per practice population. There was a difference in the cumulative rate of positive specimens per practice population over a 9-year period (P < 0·001). Neither the specimen rate per practice for a single year nor the cumulative rate of positive specimens over multiple years demonstrated significant spatial correlation. Hence, spatial variation in the incidence of giardiasis is unlikely to be confounded by variation in GP rate of specimens.

Antibacterial Efficacy of the Compound Preparation of Traditional Chinese Drug on System Fungi Reside in Faecal Specimen of Pigeon

To investigate the efficacy of the compound preparation of traditional Chinese drug which is named KZY-2) on system fungi reside in faecal specimen of pigeon, the 66 faecal specimen of pigeon were collected from columbary of local park and residents.Each specimen which weigh 2.0g was mixed with 10ml sterile saline and the supernatant which volume was 1ml was incubated with the same volume drug which concentration were 200mɡ/ml,100mɡ/ml and 50mɡ/ml respectively at 37°C.After 24h,48h and 72h, the isolated positive rates of Cryptococcus neoformans and Candida albicans were calculated. Candida albicans was identified by gram staining, budding development, chlamydospore formation, sugar fermented test,sugar assimilated test and Cryptococcus neoformans was identified by gram staining,sugar fermented test,sugar assimilated test,urease tests,caffeic acid test, Hiss capsule staining.Results showed that the isolated positive rates of Cryptococcus neoformans and Candida albicans were 27.3%（18/66） and 16.7%（11/66） without drug action, KZY-2 could reduce the isolated positive rates of Cryptococcus neoformans and Candida albicans(P<0.05 and P<0.05).The drug concentration and action time could significantly affect the isolated positive rate which was negative correlation between them, higher drug concentration and longer incubation time,more lower the positive rate, especially the isolated positive rates of Cryptococcus neoformans are reduced 77.7%（6.1/27.3）which incubated with 200mɡ/ml drug after 72h compared with the control group.These results indicate The KZY-2 have good germicidal efficacy on Cryptococcus neoformans and Candida albicans isolated from faecal specimen of pigeon.