animal reservoir
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2022 ◽  
Vol 16 (1) ◽  
pp. e0010009
Author(s):  
Imane El Idrissi Saik ◽  
Chaimaa Benlabsir ◽  
Hassan Fellah ◽  
Meryem Lemrani ◽  
Myriam Riyad

Cutaneous leishmaniasis (CL) due to Leishmania tropica is a neglected tropical disease characterized by a wide geographical distribution in the Mediterranean basin and is endemic in several of its countries. In addition, the vector Phlebotomus sergenti is abundantly present all around the basin. Its transmission cycle is still subject to debate. In some countries, the presence of an animal reservoir has been confirmed. In Morocco, CL due to L. tropica has risen since the 1980s and has spread widely to become the most abundant form of leishmaniasis in the territory. However, the anthroponotic transmission is so far the only recognized mode, despite recordings of L. tropica infection in animal hosts. In this review article, we assess the situation of CL due to L. tropica in the Mediterranean basin with a focus on Morocco and gather knowledge about any potential zoonotic transmission in the country. A concomitant zoonotic transmission could explain the persistence of the disease in areas where human protective measures combined with vector management did not help reduce the disease burden.


2022 ◽  
Author(s):  
Thomas P. Peacock ◽  
Jonathan C Brown ◽  
Jie Zhou ◽  
Nazia Thakur ◽  
Joseph Newman ◽  
...  

At the end of 2021 a new SARS-CoV-2 variant, Omicron, emerged and quickly spread across the world. It has been demonstrated that Omicrons high number of Spike mutations lead to partial immune evasion from even polyclonal antibody responses, allowing frequent re-infection and vaccine breakthroughs. However, it seems unlikely these antigenic differences alone explain its rapid growth; here we show Omicron replicates rapidly in human primary airway cultures, more so even than the previously dominant variant of concern, Delta. Omicron Spike continues to use human ACE2 as its primary receptor, to which it binds more strongly than other variants. Omicron Spike mediates enhanced entry into cells expressing several different animal ACE2s, including various domestic avian species, horseshoe bats and mice suggesting it has an increased propensity for reverse zoonosis and is more likely than previous variants to establish an animal reservoir of SARS-CoV-2. Unlike other SARS-CoV-2 variants, however, Omicron Spike has a diminished ability to induce syncytia formation. Furthermore, Omicron is capable of efficiently entering cells in a TMPRSS2-independent manner, via the endosomal route. We posit this enables Omicron to infect a greater number of cells in the respiratory epithelium, allowing it to be more infectious at lower exposure doses, and resulting in enhanced intrinsic transmissibility.


2021 ◽  
Vol 15 (12) ◽  
pp. e0010036
Author(s):  
Barkissa Mélika Traoré ◽  
Mathurin Koffi ◽  
Martial Kassi N’Djetchi ◽  
Dramane Kaba ◽  
Jacques Kaboré ◽  
...  

Background The existence of an animal reservoir of Trypanosoma brucei gambiense (T. b. gambiense), the agent of human African trypanosomiasis (HAT), may compromise the interruption of transmission targeted by World Health Organization. The aim of this study was to investigate the presence of trypanosomes in pigs and people in the Vavoua HAT historical focus where cases were still diagnosed in the early 2010’s. Methods For the human survey, we used the CATT, mini-anion exchange centrifugation technique and immune trypanolysis tests. For the animal survey, the buffy coat technique was also used as well as the PCR using Trypanosoma species specific, including the T. b. gambiense TgsGP detection using single round and nested PCRs, performed from animal blood samples and from strains isolated from subjects positive for parasitological investigations. Results No HAT cases were detected among 345 people tested. A total of 167 pigs were investigated. Free-ranging pigs appeared significantly more infected than pigs in pen. Over 70% of free-ranging pigs were positive for CATT and parasitological investigations and 27–43% were positive to trypanolysis depending on the antigen used. T. brucei was the most prevalent species (57%) followed by T. congolense (24%). Blood sample extracted DNA of T. brucei positive subjects were negative to single round TgsGP PCR. However, 1/22 and 6/22 isolated strains were positive with single round and nested TgsGP PCRs, respectively. Discussion Free-ranging pigs were identified as a multi-reservoir of T. brucei and/or T. congolense with mixed infections of different strains. This trypanosome diversity hinders the easy and direct detection of T. b. gambiense. We highlight the lack of tools to prove or exclude with certainty the presence of T. b. gambiense. This study once more highlights the need of technical improvements to explore the role of animals in the epidemiology of HAT.


2021 ◽  
Vol 15 (12) ◽  
pp. e0010055
Author(s):  
Yun-Fu Chen ◽  
Li-Fu Liao ◽  
Na Wu ◽  
Jiang-Mei Gao ◽  
Peng Zhang ◽  
...  

Background Visceral leishmaniasis (VL) has been declared as one of the six major tropical diseases by the World Health Organization. This disease has been successfully controlled in China, except for some areas in the western region, such as the Xinjiang Autonomous Region, where both anthroponotic VL (AVL) and desert type zoonotic VL (DT-ZVL) remain endemic with sporadic epidemics. Methodology/Principal findings Here, an eleven-year survey (2004–2014) of Leishmania species, encompassing both VL types isolated from patients, sand-fly vectors and Tarim hares (Lepus yarkandensis) from the Xinjiang Autonomous Region was conducted, with a special emphasis on the hares as a potential reservoir animal for DT-ZVL. Key diagnostic genes, ITS1, hsp70 and nagt (encoding N-acetylglucosamine-1-phosphate transferase) were used for phylogenetic analyses, placing all Xinjiang isolates into one clade of the L. donovani complex. Unexpectedly, AVL isolates were found to be closely related to L. infantum, while DT-ZVL isolates were closer to L. donovani. Unrooted parsimony networks of haplotypes for these isolates also revealed their relationship. Conclusions/Significance The above analyses of the DT-ZVL isolates suggested their geographic isolation and independent evolution. The sequence identity of isolates from patients, vectors and the Tarim hares in a single DT-ZVL site provides strong evidence in support of this species as an animal reservoir.


Pathogens ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1579
Author(s):  
Piet Vellema ◽  
Inge Santman-Berends ◽  
Frederika Dijkstra ◽  
Erik van Engelen ◽  
Marian Aalberts ◽  
...  

Q fever is an almost ubiquitous zoonosis caused by Coxiella burnetii. This organism infects several animal species, as well as humans, and domestic ruminants like cattle, sheep and goats are an important animal reservoir of C. burnetii. In 2007, a sudden rise in notified human Q fever cases occurred in The Netherlands, and by the end of 2009, more than 3500 human Q fever patients had been notified. Dairy sheep and dairy goats were suspected to play a causal role in this human Q fever outbreak, and several measures were taken, aiming at a reduction of C. burnetii shedding by infected small ruminants, in order to reduce environmental contamination and thus human exposure. One of the first measures was compulsory notification of more than five percent abortion within thirty days for dairy sheep and dairy goat farms, starting 12 June 2008. After notification, an official farm inspection took place, and laboratory investigations were performed aiming at ruling out or demonstrating a causal role of C. burnetii. These measures were effective, and the number of human Q fever cases decreased; levels are currently the same as they were prior to 2007. The effect of these measures was monitored using a bulk tank milk (BTM) PCR and an antibody ELISA. The percentage PCR positive dairy herds and flocks decreased over time, and dairy sheep flocks tested PCR positive significantly less often and became PCR negative earlier compared to dairy goat herds. Although there was no difference in the percentage of dairy goat and dairy sheep farms with a C. burnetii abortion outbreak, the total number of shedding dairy sheep was much lower than the number of shedding dairy goats. Combined with the fact that Q fever patients lived mainly in the proximity of infected dairy goat farms and that no Q fever patients could be linked directly to dairy sheep farms, although this may have happened in individual cases, we conclude that dairy sheep did not play a major role in the Dutch Q fever outbreak. BTM monitoring using both a PCR and an ELISA is essential to determine a potential C. burnetii risk, not only for The Netherlands but for other countries with small ruminant dairy industries.


2021 ◽  
Author(s):  
Cecily E.D. Goodwin ◽  
Monique Léchenne ◽  
Jared K. Wilson-Aggarwal ◽  
Sidouin Metinou Koumetio ◽  
George J.F. Swan ◽  
...  
Keyword(s):  

2021 ◽  
Author(s):  
Vanessa L Hale ◽  
Patricia M Dennis ◽  
Dillon S McBride ◽  
Jacqueline M Nolting ◽  
Christopher Madden ◽  
...  

Human-to-animal spillover of SARS-CoV-2 virus has occurred in a wide range of animals, but thus far, the establishment of a new natural animal reservoir has not been detected. Here, we detected SARS-CoV-2 virus using rRT-PCR in 129 out of 360 (35.8%) free-ranging white-tailed deer (Odocoileus virginianus) from northeast Ohio (USA) sampled between January-March 2021. Deer in 6 locations were infected with at least 3 lineages of SARS-CoV-2 (B.1.2, B.1.596, B.1.582). The B.1.2 viruses, dominant in Ohio at the time, spilled over multiple times into deer populations in different locations. Deer-to-deer transmission may have occurred in three locations. The establishment of a natural reservoir of SARS-CoV-2 in white-tailed deer could facilitate divergent evolutionary trajectories and future spillback to humans, further complicating long-term COVID-19 control strategies.


2021 ◽  
Vol 15 (9) ◽  
pp. 2202-2206
Author(s):  
Maryam Khaled ◽  
Mahnoor Mohydin ◽  
Hamza Tahir ◽  
W. Haider Zaidi ◽  
M. H. U Rasheed ◽  
...  

Aim: To assess the level of knowledge and awareness of undergraduate medical students in order to determine whether the undergraduate virology course is up to standard for preparation of the COVID-19 pandemic. Methodology: A cross-sectional study was conducted online by random-sampling method with a multi-central approach. Data was collected from 311 respondents for a time period of one month during May 2020. IRB approval was granted. Descriptive analysis was done on student demographics, their knowledge and opinions, using the research tool SPSS 24. Results: Majority of students had factually correct knowledge about Covid-19, according to the WHO guidelines. However, there was poor knowledge regarding animal reservoirs and other diseases caused by Coronaviruses. Most students had learned about Coronaviruses from sources apart from the syllabi or course material and 93% were in agreement for wanting an improved Coronavirus module in their undergraduate virology courses. Conclusion: Medical students have good knowledge about Coronavirus, but are lacking in some crucial topics such as sources of animal reservoir and types of diseases etc. More studies need to be conducted in order to assess whether undergraduate syllabi are sufficient for educating and training students about future possible pandemics. An efficient prospective course of action should be determined accordingly. Keywords: Medical students, Coronaviruses, Covid-19, Pandemic, Knowledge, Awareness.


2021 ◽  
Author(s):  
Sarah Temmam ◽  
Khamsing Vongphayloth ◽  
Eduard Baquero Salazar ◽  
Sandie Munier ◽  
Max Bonomi ◽  
...  

Abstract The animal reservoir of SARS-CoV-2 is unknown despite reports of various SARS-CoV-2-related viruses in Asian Rhinolophus bats, including the closest virus from R. affinis, RaTG13. Several studies have suggested the involvement of pangolin coronaviruses in SARS-CoV-2 emergence. SARS-CoV-2 presents a mosaic genome, to which different progenitors contribute. The spike sequence determines the binding affinity and accessibility of its receptor-binding domain (RBD) to the cellular angiotensin-converting enzyme 2 (ACE2) receptor and is responsible for host range. SARS-CoV-2 progenitor bat viruses genetically close to SARS-CoV-2 and able to enter human cells through a human ACE2 pathway have not yet been identified, though they would be key in understanding the origin of the epidemics. Here we show that such viruses indeed circulate in cave bats living in the limestone karstic terrain in North Laos, within the Indochinese peninsula. We found that the RBDs of these viruses differ from that of SARS-CoV-2 by only one or two residues, bind as efficiently to the hACE2 protein as the SARS-CoV-2 Wuhan strain isolated in early human cases, and mediate hACE2-dependent entry into human cells, which is inhibited by antibodies neutralizing SARS-CoV-2. None of these bat viruses harbors a furin cleavage site in the spike. Our findings therefore indicate that bat-borne SARS-CoV-2-like viruses potentially infectious for humans circulate in Rhinolophus spp. in the Indochinese peninsula.


2021 ◽  
Author(s):  
Philippe Colson ◽  
Pierre-Edouard Fournier ◽  
Herve Chaudet ◽  
Jeremy Delerce ◽  
Audrey GIRAUD-GATINEAU ◽  
...  

After the end of the first epidemic episode of SARS-CoV-2 infections, as cases began to rise again during the summer of 2020, we at IHU Mediterranee Infection in Marseille, France, intensified the genomic surveillance of SARS-CoV-2, and described the first viral variants. In this study, we compared the incidence curves of SARS-CoV-2-associated deaths in different countries and reported the classification of SARS-CoV-2 variants detected in our institute, as well as the kinetics and sources of the infections. We used mortality collected from a COVID-19 data repository for 221 countries. Viral variants were defined based on ≥5 hallmark mutations shared by ≥30 genomes. SARS-CoV-2 genotype was determined for 24,181 patients using next-generation genome and gene sequencing (in 47% and 11% of cases, respectively) or variant-specific qPCR (in 42% of cases). Sixteen variants were identified by analysing viral genomes from 9,788 SARS-CoV-2-diagnosed patients. Our data show that since the first SARS-CoV-2 epidemic episode in Marseille, importation through travel from abroad was documented for seven of the new variants. In addition, for the B.1.160 variant of Pangolin classification (a.k.a. Marseille-4), we suspect transmission from mink farms. In conclusion, we observed that the successive epidemic peaks of SARS-CoV-2 infections are not linked to rebounds of viral genotypes that are already present but to newly-introduced variants. We thus suggest that border control is the best mean of combating this type of introduction, and that intensive control of mink farms is also necessary to prevent the emergence of new variants generated in this animal reservoir.


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