scholarly journals Triatomine Feeding Profiles and Trypanosoma cruzi Infection, Implications in Domestic and Sylvatic Transmission Cycles in Ecuador

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 42
Author(s):  
Sofía Ocaña-Mayorga ◽  
Juan José Bustillos ◽  
Anita G. Villacís ◽  
C. Miguel Pinto ◽  
Simone Frédérique Brenière ◽  
...  
Keyword(s):  
Blood Meal ◽  
Mitochondrial Gene ◽  
Intestinal Content ◽  
Human Infection ◽  
Dispersal Capacity ◽  
Transmission Cycle ◽  
Rhodnius Ecuadoriensis ◽  
Transmission Cycles ◽  
Endemic Areas ◽  
Southern Highland

Understanding the blood meal patterns of insects that are vectors of diseases is fundamental in unveiling transmission dynamics and developing strategies to impede or decrease human–vector contact. Chagas disease has a complex transmission cycle that implies interactions between vectors, parasites and vertebrate hosts. In Ecuador, limited data on human infection are available; however, the presence of active transmission in endemic areas has been demonstrated. The aim of this study was to determine the diversity of hosts that serve as sources of blood for triatomines in domestic, peridomestic and sylvatic transmission cycles, in two endemic areas of Ecuador (central coastal and southern highland regions). Using conserved primers and DNA extracted from 507 intestinal content samples from five species of triatomines (60 Panstrongylus chinai, 17 Panstrongylus howardi, 1 Panstrongylus rufotuberculatus, 427 Rhodnius ecuadoriensis and 2 Triatoma carrioni) collected from 2006 to 2013, we amplified fragments of the cytb mitochondrial gene. After sequencing, blood meal sources were identified in 416 individuals (146 from central coastal and 270 from southern highland regions), achieving ≥ 95% identity with GenBank sequences (NCBI-BLAST tool). The results showed that humans are the main source of food for triatomines, indicating that human–vector contact is more frequent than previously thought. Although other groups of mammals, such as rodents, are also an available source of blood, birds (particularly chickens) might have a predominant role in the maintenance of triatomines in these areas. However, the diversity of sources of blood found might indicate a preference driven by triatomine species. Moreover, the presence of more than one source of blood in triatomines collected in the same place indicated that dispersal of vectors occurs regardless the availability of food. Dispersal capacity of triatomines needs to be evaluated to propose an effective strategy that limits human–vector contact and, in consequence, to decrease the risk of T. cruzi transmission.

scholarly journals Disentangling Trypanosoma cruzi transmission cycle dynamics through the identification of blood meal sources of natural populations of Triatoma dimidiata in Yucatán, Mexico

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Joel Israel Moo-Millan ◽  
Audrey Arnal ◽  
Silvia Pérez-Carrillo ◽  
Anette Hernandez-Andrade ◽  
María-Jesús Ramírez-Sierra ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Blood Meal ◽  
Control Strategies ◽  
Yucatan Peninsula ◽  
Universal Primers ◽  
Effective Control ◽  
Transmission Cycle ◽  
Yucatán Peninsula ◽  
Transmission Cycles ◽  
Blood Meals

Abstract Background In the Yucatán Peninsula, Mexico, Triatoma dimidiata is the main vector of Trypanosoma cruzi, the causative agent of Chagas disease. Little effort has been made to identify blood meal sources of T. dimidiata in natural conditions in this region, although this provides key information to disentangle T. cruzi transmission cycles and dynamics and guide the development of more effective control strategies. We identified the blood meals of a large sample of T. dimidiata bugs collected in different ecotopes simultaneously with the assessment of bug infection with T. cruzi, to disentangle the dynamics of T. cruzi transmission in the region. Methods A sample of 248 T. dimidiata bugs collected in three rural villages and in the sylvatic habitat surrounding these villages was used. DNA from each bug midgut was extracted and bug infection with T. cruzi was assessed by PCR. For blood meal identification, we used a molecular assay based on cloning and sequencing following PCR amplification with vertebrate universal primers, and allowing the detection of multiple blood meals in a single bug. Results Overall, 28.7% of the bugs were infected with T. cruzi, with no statistical difference between bugs from the villages or from sylvatic ecotopes. Sixteen vertebrate species including domestic, synanthropic and sylvatic animals, were identified as blood meal sources for T. dimidiata. Human, dog and cow were the three main species identified, in bugs collected in the villages as well as in sylvatic ecotopes. Importantly, dog was highlighted as the main blood meal source after human. Dog was also the most frequently identified animal together with human within single bugs, and tended to be associated with the infection of the bugs. Conclusions Dog, human and cow were identified as the main mammals involved in the connection of sylvatic and domestic transmission cycles in the Yucatán Peninsula, Mexico. Dog appeared as the most important animal in the transmission pathway of T. cruzi to humans, but other domestic and synanthropic animals, which most were previously reported as important hosts of T. cruzi in the region, were evidenced and should be taken into account as part of integrated control strategies aimed at disrupting parasite transmission.

scholarly journals Occurrence of Antibodies against SARS-CoV-2 in the Domestic Cat Population of Germany

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 772
Author(s):  
Anna Michelitsch ◽  
Donata Hoffmann ◽  
Kerstin Wernike ◽  
Martin Beer
Keyword(s):  
Neutralizing Antibodies ◽  
Large Scale ◽  
Close Contact ◽  
Companion Animals ◽  
Cross Reactivity ◽  
Human Infection ◽  
Domestic Cat ◽  
Domestic Cats ◽  
Serum Samples ◽  
Transmission Cycle

Domestic cats (Felis catus) are popular companion animals that live in close contact with their human owners. Therefore, the risk of a trans-species spreading event between domestic cats and humans is ever-present. Shortly after the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid spread around the world, the role of domestic cats in the transmission cycle was questioned. In the present study, the first large-scale survey of antibody occurrence in the domestic cat population in Germany was conducted, in order to assess the incidence of naturally occurring human to cat transmission of SARS-CoV-2. A total of 920 serum samples, which were collected from April to September of 2020, were screened by an indirect multispecies ELISA. Positive samples were verified using an indirect immunofluorescence test (iIFT) and additionally tested for neutralizing antibodies. Furthermore, serum samples were screened for antibodies against feline coronavirus (FCoV), in order to rule out cross-reactivity in the described test systems. Overall, 0.69% (6/920) of serum samples were found to be positive for antibodies against SARS-CoV-2 by ELISA and iIFT. Two of these reactive sera also displayed neutralizing antibodies. No cross-reactivity with FCoV-specific antibodies was observed. The finding of SARS-CoV-2 antibody-positive serum samples in the domestic cat population of Germany, during a period when the incidence of human infection in the country was still rather low, indicates that human-to-cat transmission of SARS-CoV-2 happens, but there is no indication of SARS-CoV-2 circulation in cats.

scholarly journals Proximity of Residence to Bodies of Water and Risk for West Nile Virus Infection: A Case-Control Study in Houston, Texas

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Melissa S. Nolan ◽  
Ana Zangeneh ◽  
Salma A. Khuwaja ◽  
Diana Martinez ◽  
Susan N. Rossmann ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Disease Surveillance ◽  
West Nile Virus Infection ◽  
Water Source ◽  
Water Sources ◽  
Human Infection ◽  
West Nile ◽  
Transmission Cycle ◽  
Increased Risk ◽  
Slow Moving

West Nile virus (WNV), a mosquito-borne virus, has clinically affected hundreds of residents in the Houston metropolitan area since its introduction in 2002. This study aimed to determine if living within close proximity to a water source increases one’s odds of infection with WNV. We identified 356 eligible WNV-positive cases and 356 controls using a population proportionate to size model with US Census Bureau data. We found that living near slow moving water sources was statistically associated with increased odds for human infection, while living near moderate moving water systems was associated with decreased odds for human infection. Living near bayous lined with vegetation as opposed to concrete also showed increased risk of infection. The habitats of slow moving and vegetation lined water sources appear to favor the mosquito-human transmission cycle. These methods can be used by resource-limited health entities to identify high-risk areas for arboviral disease surveillance and efficient mosquito management initiatives.

Trypanosoma cruzi-triatomine associations and the presence of mixed infections in single triatomine bugs in Paraná state, Brazil

2007 ◽  
Vol 52 (1) ◽  
Author(s):  
Fernanda Spitzner ◽  
Jorge Freitas ◽  
Andréa Macedo ◽  
Max Ornelas Toledo ◽  
Silvana Araújo ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Mitochondrial Gene ◽  
Reference Sample ◽  
The State ◽  
Panstrongylus Megistus ◽  
Transmission Cycle ◽  
Triatomine Bugs ◽  
Triatoma Sordida ◽  
Triatomine Species ◽  
Coii Gene

AbstractEighteen strains of Trypanosoma cruzi isolated from two species of triatomines in the state of Paraná, Brazil, were characterized molecularly using three strategies: RAPD (randomly amplified polymorphic DNA) with four primers, analysis of the D7 polymorphic region of the 24Sα rDNA, and RFLP (restriction fragment length polymorphism) of region 5′ of the mitochondrial gene COII (cytochrome oxidase subunit 2). The phenogram constructed with the RAPD data showed that only three strains isolated from Panstrongylus megistus collected in the Municipality of Arapongas were grouped together in a sub-branch. None of the other 15 strains could be clustered according to triatomine species or geographical origin. The strains were grouped with the T. cruzi I reference sample, indicating closer association with the sylvatic transmission cycle of T. cruzi in the state of Paraná. However, analyses of the rDNA and COII gene polymorphisms revealed the presence of populations from both T. cruzi I and II major lineages. In half of the analyzed triatomines, we found parasites from both lineages coinfecting the same bugs. Of these, most (6/9) were isolated from Triatoma sordida, and 3/9 from Panstrongylus megistus. These results contribute to a better comprehension of the ecoepidemiology of Chagas’ disease in Paraná, and raise questions about the role of studies of polyclonal population dynamics for controlling the transmission of T. cruzi to humans in this region.

scholarly journals Brucella Melitensis Review of the Human Infection Case

2006 ◽  
Vol 6 (1) ◽  
pp. 15-18 ◽  
Author(s):  
Šukrija Zvizdić ◽  
Dževad Čengić ◽  
Maja Bratić ◽  
Snježana Mehanić ◽  
Fikret Pinjo ◽  
...  
Keyword(s):  
Brucella Melitensis ◽  
Diagnostic Yield ◽  
Joint Infection ◽  
Human Infection ◽  
Optimal Treatment ◽  
Joint Aspiration ◽  
Joint Infections ◽  
Prosthetic Joint ◽  
Prosthetic Joint Infections ◽  
Endemic Areas

Brucella spp. prosthetic joint infections are infrequently reported in the literature, particularly in returning travellers, and optimal treatment is unknown.METHOD:We describe a prosthetic joint infection (PJI) caused by Brucella melitensis in a traveller returning to the UK from Thailand, which we believe to be the first detailed report of brucellosis in a traveller returning from this area. The 23 patients with Brucella-related PJI reported in the literature are summarised, together with our case.RESULTS:The diagnosis of Brucella-related PJI is difficult to make; only 30% of blood cultures and 75% of joint aspiration cultures were positive in the reported cases. Culture of intraoperative samples provides the best diagnostic yield. In the absence of radiological evidence of joint loosening, combination antimicrobial therapy alone may be appropriate treatment in the first instance; this was successful in 6/7 [86%] of patients, though small numbers of patients and the likelihood of reporting bias warrant caution in drawing any firm conclusions about optimal treatment. Aerosolisation of synovial fluid during joint aspiration procedures and nosocomial infection has been described.CONCLUSIONS:Brucella-related PJI should be considered in the differential of travellers returning from endemic areas with PJI, including Thailand. Personal protective equipment including fit tested filtering face piece-3 (FFP3) mask or equivalent is recommended for personnel carrying out joint aspiration when brucellosis is suspected. Travellers can reduce the risk of brucellosis by avoiding unpasteurised dairy products and animal contact (particularly on farms and abattoirs) in endemic areas and should be counselled regarding these risks as part of their pre-travel assessment.

scholarly journals Cold plasma for SARS-CoV-2 Inactivation

2020 ◽  
Author(s):  
Zhitong Chen ◽  
Gustavo Garcia ◽  
Vaithilingaraja Arumugaswami ◽  
Richard E. Wirz
Keyword(s):  
Cold Plasma ◽  
Effective Means ◽  
Virus Transmission ◽  
Human Infection ◽  
Atmospheric Plasma ◽  
Cold Atmospheric Plasma ◽  
Transmission Cycle ◽  
Plastic Metal

SARS-CoV-2 infectious virions are viable on various surfaces (e.g., plastic, metals, cardboard) for several hours. This presents a transmission cycle for the human infection that can be broken by developing new inactivation approaches. We employed an efficient cold atmospheric plasma (CAP) with argon feed gas to inactivate SARS-CoV-2 on various surfaces including plastic, metal, cardboard, basketball composite leather, football leather, and baseball leather. These results demonstrate the great potential of CAP as a safe and effective means to prevent virus transmission and infections.

scholarly journals Genetic diversity of Trypanosoma cruzi parasites infecting dogs in southern Louisiana sheds light on parasite transmission cycles and serological diagnostic performance

2020 ◽  
Vol 14 (12) ◽  
pp. e0008932
Author(s):  
Eric Dumonteil ◽  
Ardem Elmayan ◽  
Alicia Majeau ◽  
Weihong Tu ◽  
Brandy Duhon ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Trypanosoma Cruzi ◽  
Test Performance ◽  
Serological Test ◽  
Parasite Transmission ◽  
Parasite Diversity ◽  
Serological Tests ◽  
Transmission Cycle ◽  
Southern Us ◽  
Transmission Cycles

Background Chagas disease is a neglected zoonosis of growing concern in the southern US, caused by the parasite Trypanosoma cruzi. We genotyped parasites in a large cohort of PCR positive dogs to shed light on parasite transmission cycles and assess potential relationships between parasite diversity and serological test performance. Methodology/principal findings We used a metabarcoding approach based on deep sequencing of T. cruzi mini-exon marker to assess parasite diversity. Phylogenetic analysis of 178 sequences from 40 dogs confirmed the presence of T. cruzi discrete typing unit (DTU) TcI and TcIV, as well as TcII, TcV and TcVI for the first time in US dogs. Infections with multiple DTUs occurred in 38% of the dogs. These data indicate a greater genetic diversity of T. cruzi than previously detected in the US. Comparison of T. cruzi sequence diversity indicated that highly similar T. cruzi strains from these DTUs circulate in hosts and vectors in Louisiana, indicating that they are involved in a shared T. cruzi parasite transmission cycle. However, TcIV and TcV were sampled more frequently in vectors, while TcII and TcVI were sampled more frequently in dogs. Conclusions/significance These observations point to ecological host-fitting being a dominant mechanism involved in the diversification of T. cruzi-host associations. Dogs with negative, discordant or confirmed positive T. cruzi serology harbored TcI parasites with different mini-exon sequences, which strongly supports the hypothesis that parasite genetic diversity is a key factor affecting serological test performance. Thus, the identification of conserved parasite antigens should be a high priority for the improvement of current serological tests.

scholarly journals The efficacy of recombinant protein lbk39 for the diagnosis of leishmaniosis in dogs

Parasitology ◽  
2020 ◽  
pp. 1-9
Author(s):  
Joyce Carvalho Pereira ◽  
Pedro Dos Santos Sousa ◽  
Ligia Moraes Barizon De Souza ◽  
Aline Kuhn Sbruzzi Pasquali ◽  
Michelle Bates ◽  
...  
Keyword(s):  
Recombinant Protein ◽  
Amino Acid Identity ◽  
Human Infection ◽  
Antibody Detection ◽  
Leishmania Braziliensis ◽  
Total Extract ◽  
Elimination Programme ◽  
Long Time ◽  
Endemic Areas ◽  
Visceral Leishmaniosis

Abstract Visceral leishmaniosis is one of the most important zoonotic diseases on the planet and dogs are the main reservoir of canine visceral leishmaniosis (CVL) in endemic areas. They play an important role in human infection because in dogs the disease appears long time after infection, and they can move uncontrollably, contributing to disperse the parasite. To take the decision to treat the animals or for euthanasia, in an elimination programme, in order to reduce the parasitic load, it is necessary to diagnose correctly, having more effective tools. Our group has developed a new recombinant antigen-based kinesin-related gene of Leishmania braziliensis (Lbk39), which shows 59% amino acid identity to the L. infantum homologue. The Lbk39 gene was synthesized, inserted into the pLEXSY-sat2 vector and transfected into L. tarentolae cells by electroporation. The recombinant protein was secreted in the culture with a C-terminal histidine marker, purified, generating a product at 337.68 μg mL−1. A total of 152 sera from dog's endemic and non-endemic areas were used, being 78 positives and 75 negatives. The antigen Lbk39 showed 100% sensitivity and 96.1% specificity. We compared this antigen with other antigens such as total extract of the parasite, TRDPP, and our data indicate that Lbk39 has potential application in the diagnosis of CVL through antibody detection.

scholarly journals Blood Meal Sources of Anopheles spp. in Malaria Endemic Areas of Honduras

Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 450
Author(s):  
Denis Escobar ◽  
Krisnaya Ascencio ◽  
Andrés Ortiz ◽  
Adalid Palma ◽  
Ana Sánchez ◽  
...  
Keyword(s):  
Blood Meal ◽  
Host Animal ◽  
Specific Primers ◽  
Anopheles Mosquitoes ◽  
Single Host ◽  
Life Threatening ◽  
Animal Hosts ◽  
Endemic Areas ◽  
Species Specific ◽  
Feeding Sources

Malaria remains a life-threatening disease in many tropical countries. Honduras has successfully reduced malaria transmission as different control methods have been applied, focusing mainly on indoor mosquitoes. The selective pressure exerted by the use of insecticides inside the households could modify the feeding behavior of the mosquitoes, forcing them to search for available animal hosts outside the houses. These animal hosts in the peridomicile could consequently become an important factor in maintaining vector populations in endemic areas. Herein, we investigated the blood meal sources and Plasmodium spp. infection on anophelines collected outdoors in endemic areas of Honduras. Individual PCR reactions with species-specific primers were used to detect five feeding sources on 181 visibly engorged mosquitoes. In addition, a subset of these mosquitoes was chosen for pathogen analysis by a nested PCR approach. Most mosquitoes fed on multiple hosts (2 to 4), and 24.9% of mosquitoes had fed on a single host, animal or human. Chicken and bovine were the most frequent blood meal sources (29.5% and 27.5%, respectively). The average human blood index (HBI) was 22.1%. None of the mosquitoes were found to be infected with Plasmodium spp. Our results show the opportunistic and zoophilic behavior of Anopheles mosquitoes in Honduras.

scholarly journals Mitochondrial genome of Plasmodium vivax/simium detected in an endemic region for malaria in the Atlantic Forest of Espírito Santo state, Brazil: do mosquitoes, simians and humans harbor the same parasite?

2017 ◽  
Author(s):  
JC Buery ◽  
PT Rodrigues ◽  
L Natal ◽  
LC Salla ◽  
AC Loss ◽  
...  
Keyword(s):  
Mitochondrial Genome ◽  
Plasmodium Vivax ◽  
Atlantic Forest ◽  
Complete Mitochondrial Genome ◽  
Haplotype Network ◽  
The State ◽  
Espírito Santo ◽  
Transmission Cycle ◽  
Transmission Cycles ◽  
Espirito Santo

AbstractBackgroundThe transmission of malaria in the extra-Amazonian regions of Brazil, although interrupted in the 1960s, has persisted to the present time in some areas of dense Atlantic Forest, with reports of cases characterized by particular transmission cycles and clinical presentations. Bromeliad-malaria, as it is named, is particularly frequent in the state of Espírito Santo, with Plasmodium vivax being the parasite commonly recognized as the etiologic agent of human infections. With regard to the spatial and temporal distances between cases reported in this region, the transmission cycle does not fit the traditional malaria cycle. The existence of a zoonosis, with infected simians participating in the epidemiology, is therefore hypothesized. In the present study, zoonotic transmission of bromeliad-malaria in Espírito Santo is investigated, based on the complete mitochondrial genome of DNA extracted from isolates of Plasmodium species which had infected humans, a simian from the genus Allouata, and Anopheles mosquitoes. Plasmodium vivax/simium was identified in the samples by both nested-PCR and real-time PCR. After amplification, the mitochondrial genome was completely sequenced and compared in a haplotype network, including all sequences of P. vivax/simium mitochondrial genomes sampled from humans and simians from all regions in Brazil.ResultsThe haplotype network demonstrates that humans and simians from the Atlantic Forest share the same haplotype, but some isolates from humans are not identical to the simian isolate. In addition, the plasmodial DNA extracted from mosquitoes revealed sequences different from those obtained from simians, but similar to two isolates from humans.ConclusionsThese findings reinforce the hypothesis that in the Atlantic Forest, and especially in the state with the highest frequency of bromeliad-malaria in Brazil, the same parasite species is shared by humans and simians, at least in part. The difference between the sequences of mosquitoes and simians raises two hypotheses: (1) two distinct transmission cycles for human malaria exist in the study area, one of them involving simians and the other exclusive to human hosts, or (2) there is only one transmission cycle involving humans and simians, but the identification of variations among simians was not possible due to a lack of other samples.

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