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Jiang A, Lee M, Selvaraj P, Degefa T, Getachew H, Merga H, Yewhalaw D, Yan G, Hsu K. Investigating the Impact of Irrigation on Malaria Vector Larval Habitats and Transmission Using a Hydrology-Based Model. Geohealth 2023; 7:e2023GH000868. [PMID: 38089068 PMCID: PMC10711417 DOI: 10.1029/2023gh000868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 10/13/2023] [Accepted: 11/20/2023] [Indexed: 02/01/2024]
Abstract
A combination of accelerated population growth and severe droughts has created pressure on food security and driven the development of irrigation schemes across sub-Saharan Africa. Irrigation has been associated with increased malaria risk, but risk prediction remains difficult due to the heterogeneity of irrigation and the environment. While investigating transmission dynamics is helpful, malaria models cannot be applied directly in irrigated regions as they typically rely only on rainfall as a source of water to quantify larval habitats. By coupling a hydrologic model with an agent-based malaria model for a sugarcane plantation site in Arjo, Ethiopia, we demonstrated how incorporating hydrologic processes to estimate larval habitats can affect malaria transmission. Using the coupled model, we then examined the impact of an existing irrigation scheme on malaria transmission dynamics. The inclusion of hydrologic processes increased the variability of larval habitat area by around two-fold and resulted in reduction in malaria transmission by 60%. In addition, irrigation increased all habitat types in the dry season by up to 7.4 times. It converted temporary and semi-permanent habitats to permanent habitats during the rainy season, which grew by about 24%. Consequently, malaria transmission was sustained all-year round and intensified during the main transmission season, with the peak shifted forward by around 1 month. Lastly, we evaluated the spatiotemporal distribution of adult vectors under the effect of irrigation by resolving habitat heterogeneity. These findings could help larval source management by identifying transmission hotspots and prioritizing resources for malaria elimination planning.
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Affiliation(s)
- Ai‐Ling Jiang
- Department of Civil and Environmental EngineeringCenter for Hydrometeorology and Remote SensingUniversity of California IrvineIrvineCAUSA
| | - Ming‐Chieh Lee
- Department of Population Health and Disease PreventionSchool of Public HealthSusan and Henry Samueli College of Health SciencesUniversity of California IrvineIrvineCAUSA
| | - Prashanth Selvaraj
- Institute for Disease ModelingBill and Melinda Gates FoundationSeattleWAUSA
| | - Teshome Degefa
- School of Medical Laboratory SciencesInstitute of HealthJimma UniversityJimmaEthiopia
- Tropical and Infectious Diseases Research Center (TIDRC)Jimma UniversityJimmaEthiopia
| | - Hallelujah Getachew
- School of Medical Laboratory SciencesInstitute of HealthJimma UniversityJimmaEthiopia
- Tropical and Infectious Diseases Research Center (TIDRC)Jimma UniversityJimmaEthiopia
- Department of Medical Laboratory TechnologyArbaminch College of Health SciencesArba MinchEthiopia
| | - Hailu Merga
- Department of EpidemiologyInstitute of HealthJimma UniversityJimmaEthiopia
| | - Delenasaw Yewhalaw
- School of Medical Laboratory SciencesInstitute of HealthJimma UniversityJimmaEthiopia
- Tropical and Infectious Diseases Research Center (TIDRC)Jimma UniversityJimmaEthiopia
| | - Guiyun Yan
- Department of Population Health and Disease PreventionSchool of Public HealthSusan and Henry Samueli College of Health SciencesUniversity of California IrvineIrvineCAUSA
| | - Kuolin Hsu
- Department of Civil and Environmental EngineeringCenter for Hydrometeorology and Remote SensingUniversity of California IrvineIrvineCAUSA
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Thapa I, Ghersi D. Modeling preferential attraction to infected hosts in vector-borne diseases. Front Public Health 2023; 11:1276029. [PMID: 38074743 PMCID: PMC10710135 DOI: 10.3389/fpubh.2023.1276029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/31/2023] [Indexed: 12/18/2023] Open
Abstract
Vector-borne infectious diseases cause more than 700,000 deaths a year and represent an increasing threat to public health worldwide. Strategies to mitigate the spread of vector-borne diseases can benefit from a thorough understanding of all mechanisms that contribute to viral propagation in human. A recent study showed that Aedes mosquitoes (the vectors for dengue and Zika virus, among others) are preferentially attracted to infected hosts. In order to determine the impact of this factor on viral spread, we built a dedicated agent-based model and parameterized it on dengue fever. We then performed a systematic study of how mosquitoes' preferential attraction for infected hosts affects viral load and persistence of the infection. Our results indicate that even small values of preferential attraction have a dramatic effect on the number of infected individuals and the persistence of the infection in the population. Taken together, our results suggests that interventions aimed at decreasing the preferential attraction of vectors for infected hosts can reduce viral transmission and thus can have public health implications.
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Ethridge BA, Dixon CJ, Vu PQ, Steadman MB, Tillman AP, Barefield NS, Ragan MC. Unusual Presentation of Coxsackievirus B and Methicillin-Sensitive Staphylococcus aureus Cellulitis Causing Sepsis. Cureus 2023; 15:e47826. [PMID: 38021765 PMCID: PMC10679847 DOI: 10.7759/cureus.47826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 10/25/2023] [Indexed: 12/01/2023] Open
Abstract
The clinical association between Coxsackievirus B (CVB) and methicillin-sensitive Staphylococcus aureus (MSSA) has not been well established in the current literature. Here, we report a case of a 29-year-old male who presented with fever and malaise 24 hours after noticing a pruritic lesion on the anterior foreleg that resembled a mosquito bite. After multiple ED visits, laboratory studies, and imaging tests, the patient was admitted for treatment of high fevers and pancytopenia. The final diagnosis was viral sepsis complicated by co-infection with MSSA.
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Affiliation(s)
- Britton A Ethridge
- Department of Research, Alabama College of Osteopathic Medicine, Dothan, USA
| | - Cory J Dixon
- Department of Research, Alabama College of Osteopathic Medicine, Dothan, USA
| | - Paul Q Vu
- Department of Research, Alabama College of Osteopathic Medicine, Dothan, USA
| | - Michael B Steadman
- Department of Research, Alabama College of Osteopathic Medicine, Dothan, USA
| | - Aaron P Tillman
- Department of Research, Alabama College of Osteopathic Medicine, Dothan, USA
| | - Natalie S Barefield
- Department of Primary Clinical Skills, Alabama College of Osteopathic Medicine, Dothan, USA
| | - Matthew C Ragan
- Department of Obstetrics and Gynecology, Aventa Specialized Women's Care, Dothan, USA
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Weiler NS, Niendorf E, Dumic I. Two Insects, Two Bites, One Patient: A Lyme Disease and Jamestown Canyon Co-infection. Cureus 2023; 15:e40222. [PMID: 37435255 PMCID: PMC10332484 DOI: 10.7759/cureus.40222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2023] [Indexed: 07/13/2023] Open
Abstract
Lyme disease (LD) is the most common tick-borne illness across the United States, caused by the bacterium Borrelia burgdorferi sensu lato and transmitted to humans by the bite of infected Ixodes ticks. Jamestown Canyon Virus (JCV) is an emerging mosquito-borne pathogen found mostly in the upper Midwest and Northeastern United States. Co-infection between these two pathogens has not been previously reported since it would require the host to be bitten by the two infected vectors at the same time. We report a 36-year-old man who presented with erythema migrans and meningitis. While erythema migrans is a pathognomonic sign of early localized Lyme disease, Lyme meningitis does not occur in this stage but in the early disseminated stage. Furthermore, CSF tests were not supportive of neuroborreliosis, and the patient was ultimately diagnosed with JCV meningitis. We review JCV infection, LD, and this first reported co-infection to illustrate the complex interaction between different vectors and pathogens and to emphasize the importance of considering co-infection in people who live in vector-endemic areas.
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Affiliation(s)
| | | | - Igor Dumic
- Hospital Medicine, Mayo Clinic, Eau Claire, USA
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5
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Olajiga OM, Marin-Lopez A, Cardenas JC, Gutierrez-Silva LY, Gonzales-Pabon MU, Maldonado-Ruiz LP, Worges M, Fikrig E, Park Y, Londono-Renteria B. Aedes aegypti anti-salivary proteins IgG levels in a cohort of DENV-like symptoms subjects from a dengue-endemic region in Colombia. Front Epidemiol 2022; 2:1002857. [PMID: 38455331 PMCID: PMC10910902 DOI: 10.3389/fepid.2022.1002857] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/20/2022] [Indexed: 03/09/2024]
Abstract
Dengue fever, caused by the dengue virus (DENV), is currently a threat to about half of the world's population. DENV is mainly transmitted to the vertebrate host through the bite of a female Aedes mosquito while taking a blood meal. During this process, salivary proteins are introduced into the host skin and blood to facilitate blood acquisition. These salivary proteins modulate both local (skin) and systemic immune responses. Several salivary proteins have been identified as immunogenic inducing the production of antibodies with some of those proteins also displaying immunomodulatory properties enhancing arboviral infections. IgG antibody responses against salivary gland extracts of a diverse number of mosquitoes, as well as antibody responses against the Ae. aegypti peptide, Nterm-34 kDa, have been suggested as biomarkers of human exposure to mosquito bites while antibodies against AgBR1 and NeSt1 proteins have been investigated for their potential protective effect against Zika virus (ZIKV) and West Nile virus infections. Thus, we were interested in evaluating whether IgG antibodies against AgBR1, NeSt1, Nterm-34 kDa peptide, and SGE were associated with DENV infections and clinical characteristics. For this, we tested samples from volunteers living in a dengue fever endemic area in Colombia in 2019 for the presence of IgG antibodies against those salivary proteins and peptides using an ELISA test. Results from this pilot study suggest an involvement of antibody responses against salivary proteins in dengue disease progression.
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Affiliation(s)
- Olayinka M. Olajiga
- Department of Entomology, Kansas State University, Manhattan, KS, United States
| | - Alejandro Marin-Lopez
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Jenny C. Cardenas
- Laboratorio Clínico, Hospital Local Los Patios, Los Patios, Colombia
| | | | | | | | - Matt Worges
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University of New Orleans, New Orleans, LA, United States
| | - Erol Fikrig
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Yoonseong Park
- Department of Entomology, Kansas State University, Manhattan, KS, United States
| | - Berlin Londono-Renteria
- Department of Entomology, Kansas State University, Manhattan, KS, United States
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University of New Orleans, New Orleans, LA, United States
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Wang C, Zeng L. The Exploitation of Host 26S Proteasome as a New Stratedy for Bacterial Pathogenicity. Front Plant Sci 2022; 13:858829. [PMID: 35432430 PMCID: PMC9009252 DOI: 10.3389/fpls.2022.858829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
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Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Depner K, Drewe JA, Garin-Bastuji B, Gonzales Rojas JL, Gortázar Schmidt C, Herskin M, Michel V, Miranda Chueca MÁ, Pasquali P, Roberts HC, Sihvonen LH, Spoolder H, Ståhl K, Velarde A, Viltrop A, Winckler C, De Clercq K, Klement E, Stegeman JA, Gubbins S, Antoniou SE, Broglia A, Van der Stede Y, Zancanaro G, Aznar I. Scientific Opinion on the assessment of the control measures of the category A diseases of Animal Health Law: African Horse Sickness. EFSA J 2021; 19:e06403. [PMID: 33552302 PMCID: PMC7856565 DOI: 10.2903/j.efsa.2021.6403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
EFSA received a mandate from the European Commission to assess the effectiveness of some of the control measures against diseases included in the Category A list according to Regulation (EU) 2016/429 on transmissible animal diseases (‘Animal Health Law’). This opinion belongs to a series of opinions where these control measures will be assessed, with this opinion covering the assessment of control measures for African Horse Sickness (AHS). In this opinion, EFSA and the AHAW Panel of experts review the effectiveness of: (i) clinical and laboratory sampling procedures, (ii) monitoring period and (iii) the minimum radius of the protection and surveillance zone, and the minimum duration of measures in these zones. The general methodology used for this series of opinions has been published elsewhere; nonetheless, specific details of the transmission kernels used for the assessment of the minimum radius of the protection and surveillance zones are shown. Several scenarios for which these control measures were assessed were designed and agreed prior to the start of the assessment. In summary, sampling procedures described in the diagnostic manual for AHS were considered efficient for all Equidae considering the high case fatality rate expected. The monitoring period (14 days) was assessed as effective in every scenario, except for those relating to the epidemiological enquiry where the risk manager should consider increasing the monitoring period, based on the awareness of keepers, environmental conditions and the vector abundance in the region. The current protection zone (100 km) comprises more than 95% of the infections from an affected establishment. Both the radius and duration of the zones could be reduced, based on local environmental conditions and the time of year of the first index case. Recommendations provided for each of the scenarios assessed aim to support the European Commission in the drafting of further pieces of legislation relating to AHS.
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Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Depner K, Drewe JA, Garin-Bastuji B, Gonzales Rojas JL, Gortázar Schmidt C, Herskin M, Michel V, Miranda Chueca MÁ, Pasquali P, Roberts HC, Sihvonen LH, Spoolder H, Ståhl K, Velarde A, Viltrop A, Winckler C, De Clercq K, Klement E, Stegeman JA, Gubbins S, Antoniou SE, Broglia A, Van der Stede Y, Zancanaro G, Aznar I. Scientific Opinion on the assessment of the control measures of the category A diseases of Animal Health Law: African Swine Fever. EFSA J 2021; 19:e06402. [PMID: 33552298 PMCID: PMC7848183 DOI: 10.2903/j.efsa.2021.6402] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
EFSA received a mandate from the European Commission to assess the effectiveness of some of the control measures against diseases included in the Category A list according to Regulation (EU) 2016/429 on transmissible animal diseases (‘Animal Health Law’). This opinion belongs to a series of opinions where these control measures will be assessed, with this opinion covering the assessment of control measures for African Swine Fever (ASF). In this opinion, EFSA and the AHAW Panel of experts reviewed the effectiveness of: (i) clinical and laboratory sampling procedures, (ii) monitoring period and (iii) the minimum radius of the protection and surveillance zone, and the minimum length of time the measures should be applied in these zones. The general methodology used for this series of opinions has been published elsewhere; nonetheless, specific details of the model used for the assessment of the laboratory sampling procedures for ASF are presented here. Here, also, the transmission kernels used for the assessment of the minimum radius of the protection and surveillance zones are shown. Several scenarios for which these control measures had to be assessed were designed and agreed prior to the start of the assessment. In summary, several sampling procedures as described in the diagnostic manual for ASF were considered ineffective and a suggestion to exclude, or to substitute with more effective procedures was made. The monitoring period was assessed as non‐effective for several scenarios and a longer monitoring period was suggested to ensure detection of potentially infected herds. It was demonstrated that the surveillance zone comprises 95% of the infections from an affected establishment, and therefore is considered effective. Recommendations provided for each of the scenarios assessed aim to support the European Commission in the drafting of further pieces of legislation, as well as for plausible ad hoc requests in relation to ASF.
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Anjos CC, Chagas CRF, Fecchio A, Schunck F, Costa-Nascimento MJ, Monteiro EF, Mathias BS, Bell JA, Guimarães LO, Comiche KJM, Valkiūnas G, Kirchgatter K. Avian Malaria and Related Parasites from Resident and Migratory Birds in the Brazilian Atlantic Forest, with Description of a New Haemoproteus Species. Pathogens 2021; 10:103. [PMID: 33494428 PMCID: PMC7912314 DOI: 10.3390/pathogens10020103] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 11/16/2022] Open
Abstract
Determining the prevalence and local transmission dynamics of parasitic organisms are necessary to understand the ability of parasites to persist in host populations and disperse across regions, yet local transmission dynamics, diversity, and distribution of haemosporidian parasites remain poorly understood. We studied the prevalence, diversity, and distributions of avian haemosporidian parasites of the genera Plasmodium, Haemoproteus, and Leucocytozoon among resident and migratory birds in Serra do Mar, Brazil. Using 399 blood samples from 66 Atlantic Forest bird species, we determined the prevalence and molecular diversity of these pathogens across avian host species and described a new species of Haemoproteus. Our molecular and morphological study also revealed that migratory species were infected more than residents. However, vector infective stages (gametocytes) of Leucocytozoon spp., the most prevalent parasites found in the most abundant migrating host species in Serra do Mar (Elaenia albiceps), were not seen in blood films of local birds suggesting that this long-distance Austral migrant can disperse Leucocytozoon parasite lineages from Patagonia to the Atlantic Forest, but lineage sharing among resident species and local transmission cannot occur in this part of Brazil. Our study demonstrates that migratory species may harbor a higher diversity and prevalence of parasites than resident species, but transportation of some parasites by migratory hosts may not always affect local transmission.
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Affiliation(s)
- Carolina C. Anjos
- Programa de Pós-Graduação em Medicina Tropical, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (C.C.A.); (E.F.M.); (B.S.M.); (K.J.M.C.)
| | | | - Alan Fecchio
- Programa de Pós-graduação em Ecologia e Conservação da Biodiversidade, Universidade Federal de Mato Grosso, Cuiabá 78060-900, Brazil;
| | - Fabio Schunck
- Comitê Brasileiro de Registros Ornitológicos—CBRO, São Paulo 04785-040, SP, Brazil;
| | - Maria J. Costa-Nascimento
- Núcleo de Estudos em Malária, Superintendência de Controle de Endemias, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-000, SP, Brazil;
| | - Eliana F. Monteiro
- Programa de Pós-Graduação em Medicina Tropical, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (C.C.A.); (E.F.M.); (B.S.M.); (K.J.M.C.)
| | - Bruno S. Mathias
- Programa de Pós-Graduação em Medicina Tropical, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (C.C.A.); (E.F.M.); (B.S.M.); (K.J.M.C.)
| | - Jeffrey A. Bell
- Department of Biology, University of North Dakota, 10 Cornell Street, Grand Forks, ND 58202, USA;
| | - Lilian O. Guimarães
- Laboratório de Bioquímica e Biologia Molecular, Superintendência de Controle de Endemias, São Paulo 01027-000, SP, Brazil;
| | - Kiba J. M. Comiche
- Programa de Pós-Graduação em Medicina Tropical, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (C.C.A.); (E.F.M.); (B.S.M.); (K.J.M.C.)
| | | | - Karin Kirchgatter
- Programa de Pós-Graduação em Medicina Tropical, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (C.C.A.); (E.F.M.); (B.S.M.); (K.J.M.C.)
- Laboratório de Bioquímica e Biologia Molecular, Superintendência de Controle de Endemias, São Paulo 01027-000, SP, Brazil;
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Abstract
On 31 of July 2019, the Public Health Agency of Sweden was alerted about an increasing number of tularaemia cases in Gävleborg, a county in central Sweden. The number of cases increased thereafter peaking at about 150 reports of illnesses every week. As at 6 October, a total of 979 cases (734 laboratory-confirmed) have been reported, mainly from counties in central Sweden. The outbreak is now considered over (as at 14 October).
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Affiliation(s)
| | | | | | | | | | - Disa Eklöf
- National Veterinary Institute, Uppsala, Sweden
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Shymanovich T, Hajhashemi N, Wasserberg G. Quantitative and Qualitative Costs of Autogeny in Phlebotomus papatasi (Diptera: Psychodidae) Sand Flies. J Med Entomol 2020; 57:852-861. [PMID: 31813978 PMCID: PMC7768683 DOI: 10.1093/jme/tjz223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Indexed: 06/10/2023]
Abstract
Most sand flies and mosquitoes require a bloodmeal for egg production, but when blood-sources are scarce, some of them can reproduce without it, so called facultative autogeny. The evolution of autogenous reproduction is thought to involve a trade-off between the benefit of reproducing in the absence of bloodmeal hosts versus the quantitative cost of reduced fecundity and/or or qualitative effect on reduced offspring development and survivorship. We blood-fed (BF) some Phlebotomous papatasi (Scopoli) sand fly females on mice while keeping others (from the same cohort) not BF. We then compared the fecundity of BF and non-blood-fed (NBF) females and also evaluated their egg mass and hatching rate, larval development rate and survivorship, pupa mass and eclosion rates, and progeny fecundity. Among NBF females, only 55% became gravid and produced three times less mature oocytes than BF ones. Autogenous females laid 3.5 and 5.7 times fewer eggs in individual and multi-female bioassays, respectively. Egg mass and hatching rate were not affected by blood-feeding. Individual-larvae bioassays suggested reduced survival during larval stages in the autogenous group. In multi-larvae bioassays, overall and especially pupae survival was significantly reduced in the autogenous group. Development rate was slower and pupal mass was reduced in progeny from autogenous mothers. These effects were particularly apparent at high larval density. Mothers' blood-feeding history did not affect daughter's fecundity. Studies on the costs of autogeny provides insights on the evolution of blood feeding. Moreover, it also provides insights regarding potential implications of autogeny to the emergence of vector-borne diseases.
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Affiliation(s)
| | - Nima Hajhashemi
- Biology Department, University of North Carolina at Greensboro, Greensboro, NC
| | - Gideon Wasserberg
- Biology Department, University of North Carolina at Greensboro, Greensboro, NC
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Abstract
BACKGROUND AND OBJECTIVES Rocky Mountain spotted fever (RMSF) is a rapidly progressive and potentially fatal tickborne disease caused by Rickettsia rickettsii. Despite current recommendations and information on the severity of RMSF, studies show that delayed recognition and treatment continues to occur. METHODS A literature search was performed on cases published in English between 1990-2017. The frequencies for demographic, clinical, and treatment variables was calculated. RESULTS A total of 340 cases from 34 articles were included. Data on rash were available for 322 patients, and 261 (80%) noted rash. Mortality was 4% (2) in those who received doxycycline within the first five days of illness, and 35% (18) when treatment was delayed beyond Day five. Twenty-four (16%) reported chronic sequelae, including speech impairment (7, 5%) and ataxia (5, 3%). INTERPRETATION AND CONCLUSION These data highlight the importance of early treatment, and add to our understanding of long-term sequelae. Early recognition by providers will facilitate appropriate treatment and reduction in morbidity and mortality.
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Affiliation(s)
- Riley Jay
- Augusta University/University of Georgia Medical Partnership, Athens, GA, USA
| | - Paige A Armstrong
- Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
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Caimano MJ, Groshong AM, Belperron A, Mao J, Hawley KL, Luthra A, Graham DE, Earnhart CG, Marconi RT, Bockenstedt LK, Blevins JS, Radolf JD. The RpoS Gatekeeper in Borrelia burgdorferi: An Invariant Regulatory Scheme That Promotes Spirochete Persistence in Reservoir Hosts and Niche Diversity. Front Microbiol 2019; 10:1923. [PMID: 31507550 PMCID: PMC6719511 DOI: 10.3389/fmicb.2019.01923] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 08/05/2019] [Indexed: 11/28/2022] Open
Abstract
Maintenance of Borrelia burgdorferi within its enzootic cycle requires a complex regulatory pathway involving the alternative σ factors RpoN and RpoS and two ancillary trans-acting factors, BosR and Rrp2. Activation of this pathway occurs within ticks during the nymphal blood meal when RpoS, the effector σ factor, transcribes genes required for tick transmission and mammalian infection. RpoS also exerts a 'gatekeeper' function by repressing σ70-dependent tick phase genes (e.g., ospA, lp6.6). Herein, we undertook a broad examination of RpoS functionality throughout the enzootic cycle, beginning with modeling to confirm that this alternative σ factor is a 'genuine' RpoS homolog. Using a novel dual color reporter system, we established at the single spirochete level that ospA is expressed in nymphal midguts throughout transmission and is not downregulated until spirochetes have been transmitted to a naïve host. Although it is well established that rpoS/RpoS is expressed throughout infection, its requirement for persistent infection has not been demonstrated. Plasmid retention studies using a trans-complemented ΔrpoS mutant demonstrated that (i) RpoS is required for maximal fitness throughout the mammalian phase and (ii) RpoS represses tick phase genes until spirochetes are acquired by a naïve vector. By transposon mutant screening, we established that bba34/oppA5, the only OppA oligopeptide-binding protein controlled by RpoS, is a bona fide persistence gene. Lastly, comparison of the strain 297 and B31 RpoS DMC regulons identified two cohorts of RpoS-regulated genes. The first consists of highly conserved syntenic genes that are similarly regulated by RpoS in both strains and likely required for maintenance of B. burgdorferi sensu stricto strains in the wild. The second includes RpoS-regulated plasmid-encoded variable surface lipoproteins ospC, dbpA and members of the ospE/ospF/elp, mlp, revA, and Pfam54 paralogous gene families, all of which have evolved via inter- and intra-strain recombination. Thus, while the RpoN/RpoS pathway regulates a 'core' group of orthologous genes, diversity within RpoS regulons of different strains could be an important determinant of reservoir host range as well as spirochete virulence.
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Affiliation(s)
- Melissa J. Caimano
- Department of Medicine, UConn Health, Farmington, CT, United States,Department of Pediatrics, UConn Health, Farmington, CT, United States,Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States,*Correspondence: Melissa J. Caimano,
| | | | - Alexia Belperron
- Department of Internal Medicine, Section of Rheumatology, Allergy and Immunology, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Jialing Mao
- Department of Internal Medicine, Section of Rheumatology, Allergy and Immunology, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Kelly L. Hawley
- Department of Pediatrics, UConn Health, Farmington, CT, United States,Division of Infectious Diseases and Immunology, Connecticut Children’s Medical Center, Hartford, CT, United States
| | - Amit Luthra
- Department of Medicine, UConn Health, Farmington, CT, United States
| | - Danielle E. Graham
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Christopher G. Earnhart
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA, United States
| | - Richard T. Marconi
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA, United States
| | - Linda K. Bockenstedt
- Department of Internal Medicine, Section of Rheumatology, Allergy and Immunology, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Jon S. Blevins
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Justin D. Radolf
- Department of Medicine, UConn Health, Farmington, CT, United States,Department of Pediatrics, UConn Health, Farmington, CT, United States,Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States,Department of Genetics and Genome Science, UConn Health, Farmington, CT, United States,Department of Immunology, UConn Health, Farmington, CT, United States
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14
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Fecchio A, Wells K, Bell JA, Tkach VV, Lutz HL, Weckstein JD, Clegg SM, Clark NJ. Climate variation influences host specificity in avian malaria parasites. Ecol Lett 2019; 22:547-557. [PMID: 30637890 DOI: 10.1111/ele.13215] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/13/2018] [Accepted: 11/28/2018] [Indexed: 12/16/2022]
Abstract
Parasites with low host specificity (e.g. infecting a large diversity of host species) are of special interest in disease ecology, as they are likely more capable of circumventing ecological or evolutionary barriers to infect new hosts than are specialist parasites. Yet for many parasites, host specificity is not fixed and can vary in response to environmental conditions. Using data on host associations for avian malaria parasites (Apicomplexa: Haemosporida), we develop a hierarchical model that quantifies this environmental dependency by partitioning host specificity variation into region- and parasite-level effects. Parasites were generally phylogenetic host specialists, infecting phylogenetically clustered subsets of available avian hosts. However, the magnitude of this specialisation varied biogeographically, with parasites exhibiting higher host specificity in regions with more pronounced rainfall seasonality and wetter dry seasons. Recognising the environmental dependency of parasite specialisation can provide useful leverage for improving predictions of infection risk in response to global climate change.
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Affiliation(s)
- Alan Fecchio
- Laboratório de Evolução e Biogeografia, Universidade Federal da Bahia, Rua Barão de Jeremoabo 147, Salvador, BA, 40170115, Brazil
| | - Konstans Wells
- Department of Biosciences, Swansea University, Swansea, SA2 8PP, UK
| | - Jeffrey A Bell
- Department of Biology, University of North Dakota, 1 Campus Drive and Cornell Street, Grand Forks, ND, 58202, USA
| | - Vasyl V Tkach
- Department of Biology, University of North Dakota, 10 Cornell Street, Grand Forks, ND, 58202, USA
| | - Holly L Lutz
- Department of Surgery, University of Chicago, 5812 S. Ellis Ave., Chicago, IL, 606372, USA.,Integrative Research Center, Field Museum of Natural History, 1400 S. Lake Shore Drive, Chicago, IL, 60605, USA
| | - Jason D Weckstein
- Department of Ornithology, Academy of Natural Sciences and Department of Biodiversity, Earth, and Environmental Sciences, Drexel University, 1900 Benjamin Franklin Parkway, Philadelphia, PA, 19103, USA
| | - Sonya M Clegg
- Edward Grey Institute of Field Ornithology, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK
| | - Nicholas J Clark
- School of Veterinary Science, University of Queensland, Gatton, Qld, Australia
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15
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Chepkemoi ST, Mararo E, Butungi H, Paredes J, Masiga D, Sinkins SP, Herren JK. Identification of Spiroplasmainsolitum symbionts in Anopheles gambiae. Wellcome Open Res 2017; 2:90. [PMID: 29152597 PMCID: PMC5668936 DOI: 10.12688/wellcomeopenres.12468.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2017] [Indexed: 12/20/2022] Open
Abstract
Background: Insect symbionts have the potential to block the transmission of vector-borne diseases by their hosts. The advancement of a symbiont-based transmission blocking strategy for malaria requires the identification and study of
Anopheles symbionts. Methods: High throughput 16S amplicon sequencing was used to profile the bacteria associated with
Anopheles gambiae sensu lato and identify potential symbionts. The polymerase chain reaction (PCR) with specific primers were subsequently used to monitor symbiont prevalence in field populations, as well as symbiont transmission patterns. Results: We report the discovery of the bacterial symbiont,
Spiroplasma, in
Anopheles gambiae in Kenya. We determine that geographically dispersed
Anopheles gambiae populations in Kenya are infected with
Spiroplasma at low prevalence levels. Molecular phylogenetics indicates that this
Anopheles gambiae associated
Spiroplasma is a member of the
insolitum clade. We demonstrate that this symbiont is stably maternally transmitted across at least two generations and does not significantly affect the fecundity or egg to adult survival of its host. Conclusions: In diverse insect species,
Spiroplasma has been found to render their host resistant to infection by pathogens. The identification of a maternally transmitted strain of
Spiroplasma in
Anopheles gambiae may therefore open new lines of investigation for the development of symbiont-based strategies for blocking malaria transmission.
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Affiliation(s)
- Sharon T Chepkemoi
- Centre for Biotechnology and Bioinformatics (CEBIB), University of Nairobi, Nairobi, Kenya.,International Centre of Insect Physiology and Ecology (ICIPE), Kasarani, Nairobi, Kenya
| | - Enock Mararo
- International Centre of Insect Physiology and Ecology (ICIPE), Kasarani, Nairobi, Kenya
| | - Hellen Butungi
- International Centre of Insect Physiology and Ecology (ICIPE), Kasarani, Nairobi, Kenya
| | - Juan Paredes
- International Centre of Insect Physiology and Ecology (ICIPE), Kasarani, Nairobi, Kenya
| | - Daniel Masiga
- International Centre of Insect Physiology and Ecology (ICIPE), Kasarani, Nairobi, Kenya
| | - Steven P Sinkins
- MRC-University of Glasgow Centre for Virus Research, Henry Wellcome Building, Glasgow, UK
| | - Jeremy K Herren
- International Centre of Insect Physiology and Ecology (ICIPE), Kasarani, Nairobi, Kenya.,MRC-University of Glasgow Centre for Virus Research, Henry Wellcome Building, Glasgow, UK
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16
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Shapiro LLM, Murdock CC, Jacobs GR, Thomas RJ, Thomas MB. Larval food quantity affects the capacity of adult mosquitoes to transmit human malaria. Proc Biol Sci 2016; 283:20160298. [PMID: 27412284 PMCID: PMC4947883 DOI: 10.1098/rspb.2016.0298] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 06/21/2016] [Indexed: 12/22/2022] Open
Abstract
Adult traits of holometabolous insects are shaped by conditions experienced during larval development, which might impact interactions between adult insect hosts and parasites. However, the ecology of larval insects that vector disease remains poorly understood. Here, we used Anopheles stephensi mosquitoes and the human malaria parasite Plasmodium falciparum, to investigate whether larval conditions affect the capacity of adult mosquitoes to transmit malaria. We reared larvae in two groups; one group received a standard laboratory rearing diet, whereas the other received a reduced diet. Emerging adult females were then provided an infectious blood meal. We assessed mosquito longevity, parasite development rate and prevalence of infectious mosquitoes over time. Reduced larval food led to increased adult mortality and caused a delay in parasite development and a slowing in the rate at which parasites invaded the mosquito salivary glands, extending the time it took for mosquitoes to become infectious. Together, these effects increased transmission potential of mosquitoes in the high food regime by 260-330%. Such effects have not, to our knowledge, been shown previously for human malaria and highlight the importance of improving knowledge of larval ecology to better understand vector-borne disease transmission dynamics.
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Affiliation(s)
- Lillian L M Shapiro
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA 16802, USA
| | - Courtney C Murdock
- College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
| | - Gregory R Jacobs
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
| | - Rachel J Thomas
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA 16802, USA
| | - Matthew B Thomas
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA 16802, USA
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17
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Abstract
BACKGROUND With about half a billion cases, of which nearly one million fatal ones, malaria constitutes one of the major infectious diseases worldwide. A recently revived effort to eliminate the disease also focuses on IT resources for its efficient control, which prominently includes the control of the mosquito vectors that transmit the Plasmodium pathogens. As part of this effort, IDOMAL has been developed and it is continually being updated. FINDINGS In addition to the improvement of IDOMAL's structure and the correction of some inaccuracies, there were some major subdomain additions such as a section on natural products and remedies, and the import, from other, higher order ontologies, of several terms, which were merged with IDOMAL terms. Effort was put on rendering IDOMAL fully compatible as an extension of IDO, the Infectious Disease Ontology. The reason for the difficulties in fully reaching that target were the inherent differences between vector-borne diseases and "classical" infectious diseases, which make it necessary to specifically adjust the ontology's architecture in order to comprise vectors and their populations. CONCLUSIONS In addition to a higher coverage of domain-specific terms and optimizing its usage by databases and decision-support systems, the new version of IDOMAL described here allows for more cross-talk between it and other ontologies, and in particular IDO. The malaria ontology is available for downloading at the OBO Foundry (http://www.obofoundry.org/cgi-bin/detail.cgi?id=malaria_ontology) and the NCBO BioPortal (http://bioportal.bioontology.org/ontologies/1311).
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Affiliation(s)
- Pantelis Topalis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece
| | - Elvira Mitraka
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas and Department of Biology, University of Crete, Heraklion, Crete, Greece
| | - Vicky Dritsou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece
| | - Emmanuel Dialynas
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece
| | - Christos Louis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas and Department of Biology, University of Crete, Heraklion, Crete, Greece
- Centre of Functional Genetics, Medical School, University of Perugia, Perugia, Italy
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18
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Farajollahi A, Fonseca DM, Kramer LD, Kilpatrick AM. "Bird biting" mosquitoes and human disease: a review of the role of Culex pipiens complex mosquitoes in epidemiology. Infect Genet Evol 2011; 11:1577-85. [PMID: 21875691 PMCID: PMC3190018 DOI: 10.1016/j.meegid.2011.08.013] [Citation(s) in RCA: 355] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 08/15/2011] [Accepted: 08/16/2011] [Indexed: 11/27/2022]
Abstract
The transmission of vector-borne pathogens is greatly influenced by the ecology of their vector, which is in turn shaped by genetic ancestry, the environment, and the hosts that are fed on. One group of vectors, the mosquitoes in the Culex pipiens complex, play key roles in the transmission of a range of pathogens including several viruses such as West Nile and St. Louis encephalitis viruses, avian malaria (Plasmodium spp.), and filarial worms. The Cx. pipiens complex includes Culex pipiens pipiens with two forms, pipiens and molestus, Culex pipiens pallens, Culex quinquefasciatus, Culex australicus, and Culex globocoxitus. While several members of the complex have limited geographic distributions, Cx. pipienspipiens and Cx. quinquefasciatus are found in all known urban and sub-urban temperate and tropical regions, respectively, across the world, where they are often principal disease vectors. In addition, hybrids are common in areas of overlap. Although gaps in our knowledge still remain, the advent of genetic tools has greatly enhanced our understanding of the history of speciation, domestication, dispersal, and hybridization. We review the taxonomy, genetics, evolution, behavior, and ecology of members of the Cx. pipiens complex and their role in the transmission of medically important pathogens. The adaptation of Cx. pipiens complex mosquitoes to human-altered environments led to their global distribution through dispersal via humans and, combined with their mixed feeding patterns on birds and mammals (including humans), increased the transmission of several avian pathogens to humans. We highlight several unanswered questions that will increase our ability to control diseases transmitted by these mosquitoes.
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Affiliation(s)
- Ary Farajollahi
- Rutgers University, Center for Vector Biology, New Brunswick, New Jersey
| | - Dina M. Fonseca
- Rutgers University, Center for Vector Biology, New Brunswick, New Jersey
| | - Laura D. Kramer
- Wadsworth Center, New York State Department of Health, Slingerlands, New York, and State University of New York at Albany, Albany, New York
| | - A. Marm Kilpatrick
- Dept. Ecology and Evolutionary Biology, University of California, Santa Cruz, California
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19
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Reiskind MH, Wund MA. Experimental assessment of the impacts of northern long-eared bats on ovipositing Culex (Diptera: Culicidae) mosquitoes. J Med Entomol 2009; 46:1037-44. [PMID: 19769034 PMCID: PMC3749376 DOI: 10.1603/033.046.0510] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The importance of predation as a mortality factor in adult mosquitoes has received only limited attention in the scientific literature. Despite the lack of consensus among researchers as to whether bats are important predators of mosquitoes, there have been no attempts to directly document the effect of bats on mosquito populations or behavior. We conducted an enclosure experiment to test the hypothesis that bats reduce the local abundance of ovipositing female mosquitoes by examining whether the northern long-eared bat (Myotis septentrionalis Trouessart) had an effect on Culex spp. (Diptera: Culicidae) oviposition, using naturally occurring mosquitoes, either through direct predation or trait mediated effects on mosquito behavior. We found a significant, 32% reduction in egg-laying activity associated with bat predation. Artificial oviposition habitats directly outside bat enclosures experienced no reduction in oviposition; we attributed the observed reduction in egg-laying activity to direct predation on ovipositing females by bats and not changes in mosquito behavior. In addition, we noted a decrease in the number of larval mosquitoes in enclosures exposed to bat predation. These results suggest the impact of aerial predators on pathogen transmission may be large, and warrants further scientific investigation.
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Affiliation(s)
- Michael H Reiskind
- Department of Ecology and Evolutionary Biology, The University of Michigan, Ann Arbor, MI 48103, USA.
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20
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Abstract
Insects are responsible for the transmission of major infectious diseases. Recent advances in insect genomics and transformation technology provide new strategies for the control of insect borne pathogen transmission and insect pest management. One such strategy is the genetic modification of insects with genes that block pathogen development. Another is to suppress insect populations by releasing either sterile males or males carrying female-specific dominant lethal genes into the environment. Although significant progress has been made in the laboratory, further research is needed to extend these approaches to the field. These insect control strategies offer several advantages over conventional insecticide-based strategies. However, the release of genetically modified insects into the environment should proceed with great caution, after ensuring its safety, and acceptance by the target populations.
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Affiliation(s)
- Eappen G Abraham
- Department of Molecular Microbiology and Immunology, John Hopkins Bloomberg School of Public Health and Johns Hopkins Malaria Research Institute, Baltimore, Maryland, USA
| | - Sung-Jae Cha
- Department of Molecular Microbiology and Immunology, John Hopkins Bloomberg School of Public Health and Johns Hopkins Malaria Research Institute, Baltimore, Maryland, USA
| | - Marcelo Jacobs-Lorena
- Department of Molecular Microbiology and Immunology, John Hopkins Bloomberg School of Public Health and Johns Hopkins Malaria Research Institute, Baltimore, Maryland, USA
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