Arthropod vectors and vector-borne pathogens: know your enemy for not succumbing the battle

Leishmaniasis is a vector-borne disease and parasitic zoonosis that occurs worldwide (i.e., Latin America, Africa and Eurasian countries; Desjeux 2005, Dahroug et al. 2010, 2011, Otranto et al. 2013). It is caused by parasitic kinetoplastids of the Leishmania genus transmitted by arthropod vectors (i.e. sandflies such as Lutzomyia spp.) and presents a great diversity of clinical profiles, depending on the affected areas (Otranto et al. 2013). This disease mainly affects humans and wild carnivoran species, mostly canids, with dogs as major reservoir hosts (Deane & Deane 1954, Silva et al. 2000, Figueiredo et al. 2008, Dantas-Torres et al. 2012). Even though domestic and wild felids are unusual reservoirs, and rarely develop the disease, several studies suggest that these species may play an important role in the epidemiology of the disease (Poli et al. 2002, Maia et al. 2008, Nasereddin et al. 2008, Dantas-Torres et al. 2012). Here we report the first record of a clinical manifestation of Leishmaniasis disease in a wild Jaguar (Panthera onca) in Quintana Roo, Mexico.

Download Full-text

Infection with Borrelia afzelii and manipulation of the egg surface microbiota have no effect on the fitness of immature Ixodes ricinus ticks

Scientific Reports ◽

10.1038/s41598-021-90177-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Georgia Hurry ◽

Elodie Maluenda ◽

Anouk Sarr ◽

Alessandro Belli ◽

Phineas T. Hamilton ◽

...

Keyword(s):

Lyme Borreliosis ◽

Ixodes Ricinus ◽

Pathogenic Bacteria ◽

Uninfected Control ◽

Controlled Study ◽

Sampling Effort ◽

Borrelia Afzelii ◽

Vector Borne Diseases ◽

Arthropod Vectors ◽

Vector Borne

AbstractArthropod vectors carry vector-borne pathogens that cause infectious disease in vertebrate hosts, and arthropod-associated microbiota, which consists of non-pathogenic microorganisms. Vector-borne pathogens and the microbiota can both influence the fitness of their arthropod vectors, and hence the epidemiology of vector-borne diseases. The bacterium Borrelia afzelii, which causes Lyme borreliosis in Europe, is transmitted among vertebrate reservoir hosts by Ixodes ricinus ticks, which also harbour a diverse microbiota of non-pathogenic bacteria. The purpose of this controlled study was to test whether B. afzelii and the tick-associated microbiota influence the fitness of I. ricinus. Eggs obtained from field-collected adult female ticks were surface sterilized (with bleach and ethanol), which reduced the abundance of the bacterial microbiota in the hatched I. ricinus larvae by 28-fold compared to larvae that hatched from control eggs washed with water. The dysbiosed and control larvae were subsequently fed on B. afzelii-infected or uninfected control mice, and the engorged larvae were left to moult into nymphs under laboratory conditions. I. ricinus larvae that fed on B. afzelii-infected mice had a significantly faster larva-to-nymph moulting time compared to larvae that fed on uninfected control mice, but the effect was small (2.4% reduction) and unlikely to be biologically significant. We found no evidence that B. afzelii infection or reduction of the larval microbiota influenced the four other life history traits of the immature I. ricinus ticks, which included engorged larval weight, unfed nymphal weight, larva-to-nymph moulting success, and immature tick survival. A retrospective power analysis found that our sampling effort had sufficient power (> 80%) to detect small effects (differences of 5% to 10%) of our treatments. Under the environmental conditions of this study, we conclude that B. afzelii and the egg surface microbiota had no meaningful effects on tick fitness and hence on the R0 of Lyme borreliosis.

Download Full-text

Infection With Borrelia Afzelii Reduces Moulting Time of Lxodes Ricinus Ticks

10.21203/rs.3.rs-139147/v1 ◽

2021 ◽

Author(s):

Georgia Hurry ◽

Elodie Maluenda ◽

Anouk Sarr ◽

Alessandro Belli ◽

Phineas Hamilton ◽

...

Keyword(s):

Pathogenic Bacteria ◽

Uninfected Control ◽

Sampling Effort ◽

Borrelia Afzelii ◽

Vector Borne Diseases ◽

Laboratory Conditions ◽

Arthropod Vectors ◽

Sufficient Power ◽

Vector Borne ◽

And Control

Abstract Arthropod vectors carry vector-borne pathogens that cause infectious disease in vertebrate hosts, and arthropod-associated non-pathogenic microorganisms. Both types of micro-organisms can influence the fitness of their arthropod vectors, and hence the epidemiology of vector-borne diseases. The bacterium Borrelia afzelii, which causes Lyme disease in Europe, is transmitted among vertebrate reservoir hosts by Ixodes ricinus ticks, which also harbour a large diversity of non-pathogenic bacteria. The purpose of this study was to test experimentally whether B. afzelii and tick-associated non-pathogenic bacteria influence the fitness of I. ricinus. Eggs obtained from field-collected adult female ticks were washed with bleach, which reduced the abundance of non-pathogenic bacteria in the hatched I. ricinus larvae by 28-fold compared to larvae that hatched from eggs washed with water. The dysbiosed and control larvae were subsequently fed on B. afzelii-infected or uninfected control mice, and the engorged larvae were allowed to moult into nymphs under laboratory conditions. I. ricinus larvae that fed on B. afzelii-infected mice had a significantly faster larva-to-nymph moulting time compared to larvae that fed on uninfected control mice. In contrast, we found no evidence that B. afzelii infection or larval dysbiosis influenced the four other life history traits of the immature I. ricinus ticks, which included engorged larval weight, unfed nymphal weight, larva-to-nymph moulting success, and immature tick survival. A power analysis found that our sampling effort had sufficient power (>80%) to detect small effects (difference of 5% – 10%) of either B. afzelii infection or larval dysbiosis. Under the laboratory conditions of our study, B. afzelii appears to be a mostly passive passenger in I. Ricinus ticks.

Download Full-text

Displaced tick-parasite interactions at the host interface

Parasitology ◽

10.1017/s003118200008495x ◽

1998 ◽

Vol 116 (S1) ◽

pp. S65-S72 ◽

Cited By ~ 42

Author(s):

P. A. Nuttall

Keyword(s):

Blood Feeding ◽

Ixodid Ticks ◽

Vertebrate Host ◽

Feeding Site ◽

Reciprocal Interactions ◽

Arthropod Vectors ◽

Bioactive Proteins ◽

Blood Sucking ◽

Antiviral Activities ◽

Vector Borne

SummaryReciprocal interactions of parasites transmitted by blood-sucking arthropod vectors have been studied primarily at the parasite–host and parasite–vector interface. The third component of this parasite triangle, the vector–host interface, has been largely ignored. Now there is growing realization that reciprocal interactions between arthropod vectors and their vertebrate hosts play a pivotal role in the survival of arthropod-borne viruses, bacteria, and protozoa. The vector–host interface is the site where the haematophagous arthropod feeds. To obtain a blood meal, the vector must overcome the host's inflammatory, haemostatic, and immune responses. This problem is greatest for ixodid ticks which may imbibe as much as 15 ml blood whilst continuously attached to their host for 10 days or more. To feed successfully, the interface between tick and host becomes a battle between the host's mechanisms for combating the tick and the tick's armoury of bioactive proteins and other chemicals which it secretes, via saliva, into the feeding lesion formed in the host's skin. Parasites entering this battlefield encounter a privileged site in their vertebrate host that has been profoundly modified by the pharmacological activities of their vector's saliva. For example, ticks suppress natural killer cells and interferons, both of which have potent antiviral activities. Not surprisingly, vector-borne parasites exploit the immunomodulated feeding site to promote their transmission and infection. Certain tick-borne viruses are so successful at this that they are transmitted from one infected tick, through the vertebrate host to a co-feeding uninfected tick, without a detectable viraemia (virus circulating in the host's blood), and with no untoward effect on the host. When such viruses do have an adverse effect on the host, they may impede their vectors' feeding. Thus important interactions between ticks and tick-borne parasites are displaced to the interface with their vertebrate host - the skin site of blood-feeding and infection.

Download Full-text

The Ecological Significance and Implications of Transovarial Transmission among the Vector-Borne Bunyaviruses: A Review

Insects ◽

10.3390/insects9040173 ◽

2018 ◽

Vol 9 (4) ◽

pp. 173 ◽

Cited By ~ 4

Author(s):

Nicholas Bergren ◽

Rebekah Kading

Keyword(s):

Horizontal Transmission ◽

Transovarial Transmission ◽

Ecological Significance ◽

Ecological Constraints ◽

Efficient Process ◽

Arthropod Vectors ◽

Vector Borne

Transovarial transmission (TOT) is a widespread and efficient process through which pathogens can be passed between generations of arthropod vectors. Many species within the order Bunyavirales utilize TOT as a means of persisting within the environment when classical horizontal transmission is not possible due to ecological constraints. The purpose of this review is to summarize previous findings regarding the ecological significance of TOT among viruses in the order Bunyavirales and identify the gaps in knowledge regarding this important mechanism of arboviral maintenance.

Download Full-text

Atelerix algirus, the North African Hedgehog: Suitable Wild Host for Infected Ticks and Fleas and Reservoir of Vector-Borne Pathogens in Tunisia

Pathogens ◽

10.3390/pathogens10080953 ◽

2021 ◽

Vol 10 (8) ◽

pp. 953

Author(s):

Ghofrane Balti ◽

Clemence Galon ◽

Moufida Derghal ◽

Hejer Souguir ◽

Souheila Guerbouj ◽

...

Keyword(s):

Real Time ◽

Coxiella Burnetii ◽

Real Time Pcr ◽

Rhipicephalus Sanguineus ◽

Wild Mammals ◽

Arthropod Vectors ◽

The North ◽

Wild Host ◽

Rickettsia Massiliae ◽

Vector Borne

Small wild mammals are an important element in the emergence and transmission of vector-borne pathogens (VBPs). Among these species, hedgehogs have been found to be a reservoir of VBPs and host of arthropod vectors. Surveillance of VBPs in wildlife and their arthropods are crucial in a one health context. We conducted an exploratory study to screen Atelerix algirus hedgehogs and their infesting ticks and fleas for VBPs using a high throughput microfluidic real-time PCR system. Tested biopsies from hedgehogs were found to be naturally infected by Theileria youngi, Hepatozoon sp., Ehrlichia ewingii, Coxiella burnetii, and Candidatus Ehrlichia shimanensis. Similarly, Haemaphysalis erinacei and Rhipicephalus sanguineus tick species were infected by Ehrlichia ewingii, Rickettsia spp., Rickettsia massiliae, Borrelia sp., Coxiella burnetii, Rickettsia lusitaniae and Anaplasma sp. Archaeopsylla erinacei fleas were infected by Rickettsia asembonensis, Coxiella burnetii, and Rickettsia massiliae. Co-infections by two and three pathogens were detected in hedgehogs and infesting ticks and fleas. The microfluidic real-time PCR system enabled us not only to detect new and unexpected pathogens, but also to identify co-infections in hedgehogs, ticks, and fleas. We suggest that hedgehogs may play a reservoir role for VBPs in Tunisia and contribute to maintaining enzootic pathogen cycles via arthropod vectors.

Download Full-text

Seroprevalence of Leishmania spp. in dogs in northern Serbia

Veterinarski glasnik ◽

10.2298/vetgl201030015m ◽

2020 ◽

Vol 74 (2) ◽

pp. 187-193

Author(s):

Doroteja Marcic ◽

Marina Zekic-Stosic ◽

Smiljana Milosevic ◽

Ivan Pusic ◽

Aleksandar Potkonjak ◽

...

Keyword(s):

Local Population ◽

Cross Sectional Study ◽

Enzyme Linked Immunosorbent Assay ◽

Canine Leishmaniosis ◽

Endemic Region ◽

Cross Sectional ◽

Arthropod Vectors ◽

Prophylactic Measures ◽

Leishmania Spp ◽

Vector Borne

Leishmaniosis is a zoonotic disease caused by Leishmania spp. Serbia was an endemic region for this disease until the second half of the 20th century. Nowadays, canine leishmaniosis appears to be a re-emerging vector-borne disease in Serbia. Its spread is enabled by the presence of Phlebotomus spp. sandflies in this region. The objective of this study was to establish the seroprevalence of Leishmania spp. in dogs being kept in shelters in Serbia and compare those that apply and those that do not apply prophylactic measures against arthropod vectors. This cross-sectional study involved 336 dogs in two regions in Northern Serbia during 2019-2020. A commercial enzyme-linked immunosorbent assay test was used to establish the prevalence of seropositive dogs. In the shelters that applied prophylactic measures against arthropod vectors, dogs were seronegative (n=52), while in those without these measures, 2.1% (6/284) were seropositive against Leishmania spp. In conclusion, the presence of dogs seropositive against Leishmania spp. in shelters that did not apply prophylactic measures may indicate that the local population of sandflies is a source of Leishmania spp. parasites.

Download Full-text

Arthropod Vectors and Vector-Borne Bacterial Pathogens in Yosemite National Park

Journal of Medical Entomology ◽

10.1603/me10040 ◽

2011 ◽

Vol 48 (1) ◽

pp. 101-110 ◽

Cited By ~ 9

Author(s):

Katryna A. Fleer ◽

Patrick Foley ◽

Lee Calder ◽

Janet E. Foley

Keyword(s):

National Park ◽

Bacterial Pathogens ◽

Yosemite National Park ◽

Arthropod Vectors ◽

Vector Borne

Download Full-text

The role of host immunity to arthropod vectors in regulating the transmission of vector borne diseases

International Journal of Tropical Insect Science ◽

10.1017/s1742758400010729 ◽

1990 ◽

Vol 11 (06) ◽

pp. 845-850

Author(s):

Ranjan Ramasamy ◽

Manthri S. Ramasamy

Keyword(s):

Host Immunity ◽

Vector Borne Diseases ◽

Arthropod Vectors ◽

Vector Borne

Download Full-text

The status of tularemia in Europe in a one-health context: a review

Epidemiology and Infection ◽

10.1017/s0950268814002398 ◽

2014 ◽

Vol 143 (10) ◽

pp. 2137-2160 ◽

Cited By ~ 60

Author(s):

G. HESTVIK ◽

E. WARNS-PETIT ◽

L. A. SMITH ◽

N. J. FOX ◽

H. UHLHORN ◽

...

Keyword(s):

Geographical Distribution ◽

Animal Health ◽

Domestic Animals ◽

Arthropod Vectors ◽

Wide Range ◽

The Status ◽

Vector Borne ◽

Public Health Hazards ◽

Potential Public Health

SUMMARYThe bacteriumFrancisella tularensiscauses the vector-borne zoonotic disease tularemia, and may infect a wide range of hosts including invertebrates, mammals and birds. Transmission to humans occurs through contact with infected animals or contaminated environments, or through arthropod vectors. Tularemia has a broad geographical distribution, and there is evidence which suggests local emergence or re-emergence of this disease in Europe. This review was developed to provide an update on the geographical distribution ofF. tularensisin humans, wildlife, domestic animals and vector species, to identify potential public health hazards, and to characterize the epidemiology of tularemia in Europe. Information was collated on cases in humans, domestic animals and wildlife, and on reports of detection of the bacterium in arthropod vectors, from 38 European countries for the period 1992–2012. Multiple international databases on human and animal health were consulted, as well as published reports in the literature. Tularemia is a disease of complex epidemiology that is challenging to understand and therefore to control. Many aspects of this disease remain poorly understood. Better understanding is needed of the epidemiological role of animal hosts, potential vectors, mechanisms of maintenance in the different ecosystems, and routes of transmission of the disease.

Download Full-text