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Mariën J, Sage M, Bangura U, Lamé A, Koropogui M, Rieger T, Soropogui B, Douno M, Magassouba N, Fichet-Calvet E. Rodent control strategies and Lassa virus: some unexpected effects in Guinea, West Africa. Emerg Microbes Infect 2024; 13:2341141. [PMID: 38597241 PMCID: PMC11034454 DOI: 10.1080/22221751.2024.2341141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 04/04/2024] [Indexed: 04/11/2024]
Abstract
The Natal multimammate mouse (Mastomys natalensis) is the host of Lassa mammarenavirus, causing Lassa haemorrhagic fever in West Africa. As there is currently no operational vaccine and therapeutic drugs are limited, we explored rodent control as an alternative to prevent Lassa virus spillover in Upper Guinea, where the disease is highly endemic in rural areas. In a seven-year experiment, we distributed rodenticides for 10-30 days once a year and, in the last year, added intensive snap trapping for three months in all the houses of one village. We also captured rodents both before and after the intervention period to assess their effectiveness by examining alterations in trapping success and infection rates (Lassa virus RNA and IgG antibodies). We found that both interventions reduced the rodent population by 74-92% but swiftly rebounded to pre-treatment levels, even already six months after the last snap-trapping control. Furthermore, while we observed that chemical control modestly decreased Lassa virus infection rates annually (a reduction of 5% in seroprevalence per year), the intensive trapping unexpectedly led to a significantly higher infection rate (from a seroprevalence of 28% before to 67% after snap trapping control). After seven years, we conclude that annual chemical control, alone or with intensive trapping, is ineffective and sometimes counterproductive in preventing Lassa virus spillover in rural villages. These unexpected findings may result from density-dependent breeding compensation following culling and the survival of a small percentage of chronically infected rodents that may spread the virus to a new susceptible generation of mice.
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Affiliation(s)
- Joachim Mariën
- Evolutionary Ecology group, Department of Biology University of Antwerp, Antwerp, Belgium
- Virus Ecology unit, Department of Biomedical sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Mickaël Sage
- Faune INNOV’ R&D – Wildlife INNOVATION, Besançon, France
| | - Umaru Bangura
- Implementation Research, Zoonoses Control group, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Alicia Lamé
- Faune INNOV’ R&D – Wildlife INNOVATION, Besançon, France
| | - Michel Koropogui
- Projet des fièvres Hémorragiques en Guinée, Laboratoire de Virologie, Conakry, Guinea
| | - Toni Rieger
- Department of Virology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Barré Soropogui
- Projet des fièvres Hémorragiques en Guinée, Laboratoire de Virologie, Conakry, Guinea
| | - Moussa Douno
- Projet des fièvres Hémorragiques en Guinée, Laboratoire de Virologie, Conakry, Guinea
| | - N’Faly Magassouba
- Projet des fièvres Hémorragiques en Guinée, Laboratoire de Virologie, Conakry, Guinea
| | - Elisabeth Fichet-Calvet
- Implementation Research, Zoonoses Control group, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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2
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John RS, Fatoyinbo HO, Hayman DTS. Modelling Lassa virus dynamics in West African Mastomys natalensis and the impact of human activities. J R Soc Interface 2024; 21:20240106. [PMID: 39045680 PMCID: PMC11267396 DOI: 10.1098/rsif.2024.0106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/25/2024] [Accepted: 06/04/2024] [Indexed: 07/25/2024] Open
Abstract
Lassa fever is a West African rodent-borne viral haemorrhagic fever that kills thousands of people a year, with 100 000 to 300 000 people a year probably infected by Lassa virus (LASV). The main reservoir of LASV is the Natal multimammate mouse, Mastomys natalensis. There is reported asynchrony between peak infection in the rodent population and peak Lassa fever risk among people, probably owing to differing seasonal contact rates. Here, we developed a susceptible-infected-recovered ([Formula: see text])-based model of LASV dynamics in its rodent host, M. natalensis, with a persistently infected class and seasonal birthing to test the impact of changes to seasonal birthing in the future owing to climate and land use change. Our simulations suggest shifting rodent birthing timing and synchrony will alter the peak of viral prevalence, changing risk to people, with viral dynamics mainly stable in adults and varying in the young, but with more infected individuals. We calculate the time-average basic reproductive number, [Formula: see text], for this infectious disease system with periodic changes to population sizes owing to birthing using a time-average method and with a sensitivity analysis show four key parameters: carrying capacity, adult mortality, the transmission parameter among adults and additional disease-induced mortality impact the maintenance of LASV in M. natalensis most, with carrying capacity and adult mortality potentially changeable owing to human activities and interventions.
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Affiliation(s)
- Reju Sam John
- Massey University, Private Bag, 11 222, Palmerston North4442, New Zealand
| | | | - David T. S. Hayman
- Massey University, Private Bag, 11 222, Palmerston North4442, New Zealand
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3
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Beck KB, Farine DR, Firth JA, Sheldon BC. Variation in local population size predicts social network structure in wild songbirds. J Anim Ecol 2023; 92:2348-2362. [PMID: 37837224 PMCID: PMC10952437 DOI: 10.1111/1365-2656.14015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 09/19/2023] [Indexed: 10/15/2023]
Abstract
The structure of animal societies is a key determinant of many ecological and evolutionary processes. Yet, we know relatively little about the factors and mechanisms that underpin detailed social structure. Among other factors, social structure can be influenced by habitat configuration. By shaping animal movement decisions, heterogeneity in habitat features, such as vegetation and the availability of resources, can influence the spatiotemporal distribution of individuals and subsequently key socioecological properties such as the local population size and density. Differences in local population size and density can impact opportunities for social associations and may thus drive substantial variation in local social structure. Here, we investigated spatiotemporal variation in population size at 65 distinct locations in a small songbird, the great tit (Parus major) and its effect on social network structure. We first explored the within-location consistency of population size from weekly samples and whether the observed variation in local population size was predicted by the underlying habitat configuration. Next, we created social networks from the birds' foraging associations at each location for each week and examined if local population size affected social structure. We show that population size is highly repeatable within locations across weeks and years and that some of the observed variation in local population size was predicted by the underlying habitat, with locations closer to the forest edge having on average larger population sizes. Furthermore, we show that local population size affected social structure inferred by four global network metrics. Using simple simulations, we then reveal that much of the observed social structure is shaped by social processes. Across different population sizes, the birds' social structure was largely explained by their preference to forage in flocks. In addition, over and above effects of social foraging, social preferences between birds (i.e. social relationships) shaped certain network features such as the extent of realized social connections. Our findings thus suggest that individual social decisions substantially contribute to shaping certain social network features over and above effects of population size alone.
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Affiliation(s)
- Kristina B. Beck
- Department of Biology, Edward Grey InstituteUniversity of OxfordOxfordUK
| | - Damien R. Farine
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurichSwitzerland
- Division of Ecology and Evolution, Research School of BiologyAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
- Department of Collective BehaviourMax Planck Institute of Animal BehaviourKonstanzGermany
| | - Josh A. Firth
- Department of Biology, Edward Grey InstituteUniversity of OxfordOxfordUK
| | - Ben C. Sheldon
- Department of Biology, Edward Grey InstituteUniversity of OxfordOxfordUK
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Leirs H, Kirkpatrick L, Sluydts V, Sabuni C, Borremans B, Katakweba A, Massawe A, Makundi R, Mulungu L, Machang'u R, Mariën J. Twenty-nine years of continuous monthly capture-mark-recapture data of multimammate mice (Mastomys natalensis) in Morogoro, Tanzania. Sci Data 2023; 10:798. [PMID: 37952006 PMCID: PMC10640561 DOI: 10.1038/s41597-023-02700-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 10/30/2023] [Indexed: 11/14/2023] Open
Abstract
The multimammate mice (Mastomys natalensis) is the most-studied rodent species in sub-Saharan Africa, where it is an important pest species in agriculture and carrier of zoonotic diseases (e.g. Lassa virus). Here, we provide a unique dataset that consists of twenty-nine years of continuous monthly capture-mark-recapture entries on one 3 ha mosaic field (MOSA) in Morogoro, Tanzania. It is one of the most accurate and long-running capture-recapture time series on a small mammal species worldwide and unique to Africa. The database can be used by ecologists to test hypotheses on the population dynamics of small mammals (e.g. to test the effect of climate change), or to validate new algorithms on real long-term field data (e.g. new survival analyses techniques). It is also useful for both scientists and decision-makers who want to optimize rodent control strategies and predict outbreaks of multimammate mice.
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Affiliation(s)
- Herwig Leirs
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Lucinda Kirkpatrick
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Vincent Sluydts
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Christopher Sabuni
- Institute of Pest Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Benny Borremans
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
| | - Abdul Katakweba
- Institute of Pest Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Apia Massawe
- Institute of Pest Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Rhodes Makundi
- Institute of Pest Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Loth Mulungu
- Institute of Pest Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Robert Machang'u
- Institute of Pest Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Joachim Mariën
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium.
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium.
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Broecke BV, Tafompa PJJ, Mwamundela BE, Bernaerts L, Ribas A, Mnyone LL, Leirs H, Mariën J. Drivers behind co-occurrence patterns between pathogenic bacteria, protozoa, and helminths in populations of the multimammate mouse, Mastomys natalensis. Acta Trop 2023; 243:106939. [PMID: 37156346 DOI: 10.1016/j.actatropica.2023.106939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 05/10/2023]
Abstract
Advances in experimental and theoretical work increasingly suggest that parasite interactions within a single host can affect the spread and severity of wildlife diseases. Yet empirical data to support predicted co-infection patterns are limited due to the practical challenges of gathering convincing data from animal populations and the stochastic nature of parasite transmission. Here, we investigated co-infection patterns between micro- (bacteria and protozoa) and macroparasites (gastro-intestinal helminths) in natural populations of the multimammate mouse (Mastomys natalensis). Fieldwork was performed in Morogoro (Tanzania), where we trapped 211 M. natalensis and tested their behaviour using a modified open-field arena. All animals were checked for the presence of helminths in their gastro-intestinal tract, three bacteria (Anaplasma, Bartonella, and Borrelia) and two protozoan genera (Babesia and Hepatozoon). Besides the presence of eight different helminth genera (reported earlier), we found that 21% of M. natalensis were positive for Anaplasma, 13% for Bartonella, and 2% for Hepatozoon species. Hierarchical modelling of species communities was used to investigate the effect of the different host-related factors on these parasites' infection probability and community structure. Our results show that the infection probability of Bartonella increased with the host's age, while the infection probability of Anaplasma peaked when individuals reached adulthood. We also observed that less explorative and stress-sensitive individuals had a higher infection probability with Bartonella. Finally, we found limited support for within-host interactions between micro-and macroparasites, as most co-infection patterns could be attributed to host exposure time.
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Affiliation(s)
- Bram Vanden Broecke
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | | | | | - Lisse Bernaerts
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Alexis Ribas
- Parasitology Section, Department of Biology, Healthcare and Environment, Faculty of Pharmacy and Food Science, Institut de Recerca de la Biodiversitat (IRBio), University of Barcelona, Barcelona, Spain
| | - Ladslaus L Mnyone
- Institute of Pest Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Herwig Leirs
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Joachim Mariën
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium; Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium.
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6
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Luna Virus and Helminths in Wild Mastomys natalensis in Two Contrasting Habitats in Zambia: Risk Factors and Evidence of Virus Dissemination in Semen. Pathogens 2022; 11:pathogens11111345. [DOI: 10.3390/pathogens11111345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
Transmission dynamics and the maintenance of mammarenaviruses in nature are poorly understood. Using metagenomic next-generation sequencing (mNGS) and RT-PCR, we investigated the presence of mammarenaviruses and co-infecting helminths in various tissues of 182 Mastomys natalensis rodents and 68 other small mammals in riverine and non-riverine habitats in Zambia. The Luna virus (LUAV) genome was the only mammarenavirus detected (7.7%; 14/182) from M. natalensis. Only one rodent from the non-riverine habitat was positive, while all six foetuses from one pregnant rodent carried LUAV. LUAV-specific mNGS reads were 24-fold higher in semen than in other tissues from males. Phylogenetically, the viruses were closely related to each other within the LUAV clade. Helminth infections were found in 11.5% (21/182) of M. natalensis. LUAV–helminth co-infections were observed in 50% (7/14) of virus-positive rodents. Juvenility (OR = 9.4; p = 0.018; 95% CI: 1.47–59.84), nematodes (OR = 15.5; p = 0.001; 95% CI: 3.11–76.70), cestodes (OR = 10.8; p = 0.025; 95% CI: 1.35–86.77), and being male (OR = 4.6; p = 0.036; 95% CI: 1.10–18.90) were associated with increased odds of LUAV RNA detection. The role of possible sexual and/or congenital transmission in the epidemiology of LUAV infections in rodents requires further study, along with the implications of possible helminth co-infection.
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7
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Rats and the city: Implications of urbanization on zoonotic disease risk in Southeast Asia. Proc Natl Acad Sci U S A 2022; 119:e2112341119. [PMID: 36122224 PMCID: PMC9522346 DOI: 10.1073/pnas.2112341119] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Urbanization is rapidly transforming Southeast Asia, altering the landscape and the interactions between people, animals, and the environment. These changes have the potential to exacerbate many existing health challenges in the region, including those posed by zoonoses. Here, we used a novel, multidisciplinary, ecosystem-level approach to examine the influence of urbanization on zoonotic disease risk in a Southeast Asian city. We infer that urbanization alters the ecology of animal reservoirs, arthropod vectors, and pathogens in a manner that may increase transmission risk from multiple zoonotic diseases in urban areas. This effect was particularly strong for pathogens associated with environmental or tick-borne transmission, providing targets for the development of low-cost interventions to reduce zoonotic disease risk in tropical cities. Urbanization is rapidly transforming much of Southeast Asia, altering the structure and function of the landscape, as well as the frequency and intensity of the interactions between people, animals, and the environment. In this study, we explored the impact of urbanization on zoonotic disease risk by simultaneously characterizing changes in the ecology of animal reservoirs (rodents), ectoparasite vectors (ticks), and pathogens across a gradient of urbanization in Kuching, a city in Malaysian Borneo. We sampled 863 rodents across rural, developing, and urban locations and found that rodent species diversity decreased with increasing urbanization—from 10 species in the rural location to 4 in the rural location. Notably, two species appeared to thrive in urban areas, as follows: the invasive urban exploiter Rattus rattus (n = 375) and the native urban adapter Sundamys muelleri (n = 331). R. rattus was strongly associated with built infrastructure across the gradient and carried a high diversity of pathogens, including multihost zoonoses capable of environmental transmission (e.g., Leptospira spp.). In contrast, S. muelleri was restricted to green patches where it was found at high densities and was strongly associated with the presence of ticks, including the medically important genera Amblyomma, Haemaphysalis, and Ixodes. Our analyses reveal that zoonotic disease risk is elevated and heterogeneously distributed in urban environments and highlight the potential for targeted risk reduction through pest management and public health messaging.
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Manlove K, Wilber M, White L, Bastille‐Rousseau G, Yang A, Gilbertson MLJ, Craft ME, Cross PC, Wittemyer G, Pepin KM. Defining an epidemiological landscape that connects movement ecology to pathogen transmission and pace‐of‐life. Ecol Lett 2022; 25:1760-1782. [DOI: 10.1111/ele.14032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/21/2022] [Accepted: 05/03/2022] [Indexed: 12/20/2022]
Affiliation(s)
- Kezia Manlove
- Department of Wildland Resources and Ecology Center Utah State University Logan Utah USA
| | - Mark Wilber
- Department of Forestry, Wildlife, and Fisheries University of Tennessee Institute of Agriculture Knoxville Tennessee USA
| | - Lauren White
- National Socio‐Environmental Synthesis Center University of Maryland Annapolis Maryland USA
| | | | - Anni Yang
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
- National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services National Wildlife Research Center Fort Collins Colorado USA
- Department of Geography and Environmental Sustainability University of Oklahoma Norman Oklahoma USA
| | - Marie L. J. Gilbertson
- Department of Veterinary Population Medicine University of Minnesota St. Paul Minnesota USA
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology University of Wisconsin–Madison Madison Wisconsin USA
| | - Meggan E. Craft
- Department of Ecology, Evolution, and Behavior University of Minnesota St. Paul Minnesota USA
| | - Paul C. Cross
- U.S. Geological Survey Northern Rocky Mountain Science Center Bozeman Montana USA
| | - George Wittemyer
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
| | - Kim M. Pepin
- National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services National Wildlife Research Center Fort Collins Colorado USA
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9
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Vanden Broecke B, Bernaerts L, Ribas A, Sluydts V, Mnyone L, Matthysen E, Leirs H. Linking Behavior, Co-infection Patterns, and Viral Infection Risk With the Whole Gastrointestinal Helminth Community Structure in Mastomys natalensis. Front Vet Sci 2021; 8:669058. [PMID: 34485424 PMCID: PMC8415832 DOI: 10.3389/fvets.2021.669058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/19/2021] [Indexed: 11/29/2022] Open
Abstract
Infection probability, load, and community structure of helminths varies strongly between and within animal populations. This can be ascribed to environmental stochasticity or due to individual characteristics of the host such as their age or sex. Other, but understudied, factors are the hosts' behavior and co-infection patterns. In this study, we used the multimammate mouse (Mastomys natalensis) as a model system to investigate how the hosts' sex, age, exploration behavior, and viral infection history affects their infection risk, parasitic load, and community structure of gastrointestinal helminths. We hypothesized that the hosts' exploration behavior would play a key role in the risk for infection by different gastrointestinal helminths, whereby highly explorative individuals would have a higher infection risk leading to a wider diversity of helminths and a larger load compared to less explorative individuals. Fieldwork was performed in Morogoro, Tanzania, where we trapped a total of 214 individual mice. Their exploratory behavior was characterized using a hole-board test after which we collected the helminths inside their gastrointestinal tract. During our study, we found helminths belonging to eight different genera: Hymenolepis sp., Protospirura muricola, Syphacia sp., Trichuris mastomysi, Gongylonema sp., Pterygodermatites sp., Raillietina sp., and Inermicapsifer sp. and one family: Trichostrongylidae. Hierarchical modeling of species communities (HMSC) was used to investigate the effect of the different host-related factors on the infection probability, parasite load, and community structure of these helminths. Our results show that species richness was higher in adults and in females compared to juveniles and males, respectively. Contrary to our expectations, we found that less explorative individuals had higher infection probability with different helminths resulting in a higher diversity, which could be due to a higher exposure rate to these helminths and/or behavioral modification due to the infection.
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Affiliation(s)
- Bram Vanden Broecke
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Lisse Bernaerts
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Alexis Ribas
- Parasitology Section, Department of Biology, Healthcare and Environment, Faculty of Pharmacy and Food Science, IRBio (Research Institute of Biodiversity), University of Barcelona, Barcelona, Spain
| | - Vincent Sluydts
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Ladslaus Mnyone
- Pest Management Center, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Erik Matthysen
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Herwig Leirs
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
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10
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Desiderio TM, Stacy NI, Ossiboff RJ, Iredale M, Archer LL, Alexander AB, Heard DJ, Crevasse SE, Craft WF, Fredholm DVE, Donnelly KA, Rosenberg JF, Childress AL, Russell K, Wellehan JFX. Identification of a novel mortality-associated Helicobacter species in gopher tortoises (Gopherus polyphemus), qPCR test development and validation, and correlation with mortality in a wildlife rehabilitation population. Vet Microbiol 2021; 259:109136. [PMID: 34214906 DOI: 10.1016/j.vetmic.2021.109136] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 05/25/2021] [Indexed: 11/27/2022]
Abstract
The genus Helicobacter includes spiral-shaped bacteria in the phylum Proteobacteria, class Epsilonproteobacteria, order Campylobacteriales, that have been associated with disease in animals, including reptiles. Three wild gopher tortoise (Gopherus polyphemus) index cases presented between 2012 and 2019 with nasal discharge, lethargy, and weight loss. Cytological examination of nasal discharge from all 3 tortoises identified marked heterophilic and mild histiocytic rhinitis with abundant extracellular and phagocytized spiral shaped bacteria that stained positive with Warthin-Starry stain. Polymerase chain reaction (PCR) and sequencing of the 16S rRNA gene revealed this to be a novel Helicobacter species. Two tortoises died despite treatment attempts, and the third was moribund and was euthanized. Histological examination of the nasal mucosa (n = 3) showed granulocytic to lymphocytic rhinitis with variable mucosal hyperplasia, erosion, and ulceration; Warthin-Starry staining highlighted the presence of spiral bacteria in the untreated tortoise. Genus-specific primers were designed, and the gyrA and groEL genes were amplified by PCR and sequenced. Phylogenetic analysis shows that this organism and other previously characterized Helicobacter from tortoises form a clade. Development and cross-validation of two qPCR diagnostic assays for the gyrA and groEL genes showed significant correlation of the results of two assays (P < 0.0001). These assays were used to survey nasal wash samples from 31 rehabilitating gopher tortoises. Mortality of tortoises significantly correlated with higher Helicobacter loads detected by qPCR (P = 0.028). Appropriate quarantine protocols for tortoises during rehabilitation should consider this organism. Upper respiratory disease in tortoises may involve complex microbial ecology; factors beyond Mycoplasmopsis (Mycoplasma) agassizii should be taken into account.
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Affiliation(s)
- Tasha M Desiderio
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Nicole I Stacy
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Robert J Ossiboff
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Marley Iredale
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Linda L Archer
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Amy B Alexander
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Darryl J Heard
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Sarah E Crevasse
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - William F Craft
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Daniel V E Fredholm
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Kyle A Donnelly
- Brevard Zoo and Sea Turtle Healing Center, Melbourne, FL, 32940, USA
| | - Justin F Rosenberg
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - April L Childress
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Kathy Russell
- Santa Fe College Teaching Zoo, Gainesville, FL, 32606, USA
| | - James F X Wellehan
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA.
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11
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Hoffmann C, Wurr S, Pallasch E, Bockholt S, Rieger T, Günther S, Oestereich L. Experimental Morogoro Virus Infection in Its Natural Host, Mastomys natalensis. Viruses 2021; 13:851. [PMID: 34067011 PMCID: PMC8151005 DOI: 10.3390/v13050851] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 01/26/2023] Open
Abstract
Natural hosts of most arenaviruses are rodents. The human-pathogenic Lassa virus and several non-pathogenic arenaviruses such as Morogoro virus (MORV) share the same host species, namely Mastomys natalensis (M. natalensis). In this study, we investigated the history of infection and virus transmission within the natural host population. To this end, we infected M. natalensis at different ages with MORV and measured the health status of the animals, virus load in blood and organs, the development of virus-specific antibodies, and the ability of the infected individuals to transmit the virus. To explore the impact of the lack of evolutionary virus-host adaptation, experiments were also conducted with Mobala virus (MOBV), which does not share M. natalensis as a natural host. Animals infected with MORV up to two weeks after birth developed persistent infection, seroconverted and were able to transmit the virus horizontally. Animals older than two weeks at the time of infection rapidly cleared the virus. In contrast, MOBV-infected neonates neither developed persistent infection nor were able to transmit the virus. In conclusion, we demonstrate that MORV is able to develop persistent infection in its natural host, but only after inoculation shortly after birth. A related arenavirus that is not evolutionarily adapted to M. natalensis is not able to establish persistent infection. Persistently infected animals appear to be important to maintain virus transmission within the host population.
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Affiliation(s)
- Chris Hoffmann
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.H.); (S.W.); (E.P.); (S.B.); (T.R.); (S.G.)
| | - Stephanie Wurr
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.H.); (S.W.); (E.P.); (S.B.); (T.R.); (S.G.)
| | - Elisa Pallasch
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.H.); (S.W.); (E.P.); (S.B.); (T.R.); (S.G.)
- German Center for Infectious Diseases (DZIF), Partner Site Hamburg, Partner Site Hamburg-Lübeck-Borstel-Riems, Germany
| | - Sabrina Bockholt
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.H.); (S.W.); (E.P.); (S.B.); (T.R.); (S.G.)
- German Center for Infectious Diseases (DZIF), Partner Site Hamburg, Partner Site Hamburg-Lübeck-Borstel-Riems, Germany
| | - Toni Rieger
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.H.); (S.W.); (E.P.); (S.B.); (T.R.); (S.G.)
| | - Stephan Günther
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.H.); (S.W.); (E.P.); (S.B.); (T.R.); (S.G.)
- German Center for Infectious Diseases (DZIF), Partner Site Hamburg, Partner Site Hamburg-Lübeck-Borstel-Riems, Germany
| | - Lisa Oestereich
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.H.); (S.W.); (E.P.); (S.B.); (T.R.); (S.G.)
- German Center for Infectious Diseases (DZIF), Partner Site Hamburg, Partner Site Hamburg-Lübeck-Borstel-Riems, Germany
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Abstract
Zoonotic diseases are infectious diseases of humans caused by pathogens that are shared between humans and other vertebrate animals. Previously, pristine natural areas with high biodiversity were seen as likely sources of new zoonotic pathogens, suggesting that biodiversity could have negative impacts on human health. At the same time, biodiversity has been recognized as potentially benefiting human health by reducing the transmission of some pathogens that have already established themselves in human populations. These apparently opposing effects of biodiversity in human health may now be reconcilable. Recent research demonstrates that some taxa are much more likely to be zoonotic hosts than others are, and that these animals often proliferate in human-dominated landscapes, increasing the likelihood of spillover. In less-disturbed areas, however, these zoonotic reservoir hosts are less abundant and nonreservoirs predominate. Thus, biodiversity loss appears to increase the risk of human exposure to both new and established zoonotic pathogens. This new synthesis of the effects of biodiversity on zoonotic diseases presents an opportunity to articulate the next generation of research questions that can inform management and policy. Future studies should focus on collecting and analyzing data on the diversity, abundance, and capacity to transmit of the taxa that actually share zoonotic pathogens with us. To predict and prevent future epidemics, researchers should also focus on how these metrics change in response to human impacts on the environment, and how human behaviors can mitigate these effects. Restoration of biodiversity is an important frontier in the management of zoonotic disease risk.
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Mariën J, Lo Iacono G, Rieger T, Magassouba N, Günther S, Fichet-Calvet E. Households as hotspots of Lassa fever? Assessing the spatial distribution of Lassa virus-infected rodents in rural villages of Guinea. Emerg Microbes Infect 2020; 9:1055-1064. [PMID: 32459576 PMCID: PMC7336995 DOI: 10.1080/22221751.2020.1766381] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/24/2020] [Accepted: 05/02/2020] [Indexed: 01/25/2023]
Abstract
The Natal multimammate mouse (Mastomys natalensis) is the reservoir host of Lassa virus (LASV), an arenavirus that causes Lassa haemorrhagic fever in humans in West Africa. While previous studies suggest that spillover risk is focal within rural villages due to the spatial behaviour of the rodents, the level of clustering was never specifically assessed. Nevertheless, detailed information on the spatial distribution of infected rodents would be highly valuable to optimize LASV-control campaigns, which are limited to rodent control or interrupting human-rodent contact considering that a human vaccine is not available. Here, we analysed data from a four-year field experiment to investigate whether LASV-infected rodents cluster in households in six rural villages in Guinea. Our analyses were based on the infection status (antibody or PCR) and geolocation of rodents (n = 864), and complemented with a phylogenetic analysis of LASV sequences (n = 119). We observed that the majority of infected rodents were trapped in a few houses (20%) and most houses were rodent-free at a specific point in time (60%). We also found that LASV strains circulating in a specific village were polyphyletic with respect to neighbouring villages, although most strains grouped together at the sub-village level and persisted over time. In conclusion, our results suggest that: (i) LASV spillover risk is heterogeneously distributed within villages in Guinea; (ii) viral elimination in one particular village is unlikely if rodents are not controlled in neighbouring villages. Such spatial information should be incorporated into eco-epidemiological models that assess the cost-efficiency of LASV control strategies.
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Affiliation(s)
- Joachim Mariën
- Department of Clinical Sciences/Outbreak Research Team, Institute of Tropical Medicine, Antwerp, Belgium
| | | | - Toni Rieger
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | | | - Stephan Günther
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
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