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Tropical Medicine and Infectious Disease Feb 2023Zoonotic infections are an emerging public health threat globally. The geographical distribution, animal reservoirs and tick vectors vary greatly across species, and... (Review)
Review
Zoonotic infections are an emerging public health threat globally. The geographical distribution, animal reservoirs and tick vectors vary greatly across species, and estimations of prevalence reported in works within the literature are also quite different. Better prevalence estimates and identification of moderators are needed to understand the global transmission risk of different zoonotic species, and to provide crucial background information for the diagnosis, treatment and control of zoonotic babesiosis. We conducted a systematic review and meta-analysis to determine the global nucleic acid prevalence of different zoonotic species in humans, animals and ticks. Relevant publications were obtained from several electronic databases and grey literature up to December 2021. Articles were included if they were published in English or Chinese and reported the nucleic acid prevalence of zoonotic species in humans, animals or ticks. The pooled estimates of prevalence were determined using a random effect model. Heterogeneity was investigated using subgroup analyses and random effect meta-regression models. Of 3205 unique studies, 28 were included by the systematic review of zoonotic for humans, 79 for animals and 104 for ticks. The results showed overall pooled estimates of nucleic acid prevalence for the following: -1.93% (0.32-4.69%) in humans; -7.80% (5.25-10.77%), -2.12% (0.73-4.08%) and -1.42% (0.30-3.16%) in animals; and -2.30% (1.59-3.13%), -0.16% (0.05-0.32%), and -0.39% (0.26-0.54%) in questing ticks. The type of population, animal reservoir or tick vector, detecting method and continent were moderators possibly associated with heterogeneity, yet the remaining heterogeneity that was not explained was still substantial (all QE values < 0.05). is the most prevalent and widely distributed zoonotic species globally. The wide range of suitable animal reservoirs and potential transmission vectors and high prevalence in animals and ticks may contribute to the worldwide distribution of . Other zoonotic species were relatively less prevalent and were reported in quite limited areas.
PubMed: 36977133
DOI: 10.3390/tropicalmed8030132 -
Pathogens (Basel, Switzerland) Feb 2021Babesiosis caused by the species is a parasitic tick-borne disease. It threatens many mammalian species and is transmitted through infected ixodid ticks. To date, the... (Review)
Review
Babesiosis caused by the species is a parasitic tick-borne disease. It threatens many mammalian species and is transmitted through infected ixodid ticks. To date, the global occurrence and distribution are poorly understood in questing ticks. Therefore, we performed a meta-analysis to estimate the distribution of the pathogen. A deep search for four electronic databases of the published literature investigating the prevalence of spp. in questing ticks was undertaken and obtained data analyzed. Our results indicate that in 104 eligible studies dating from 1985 to 2020, altogether 137,364 ticks were screened with 3069 positives with an estimated global pooled prevalence estimates (PPE) of 2.10%. In total, 19 different species of both human and veterinary importance were detected in 23 tick species, with and being the most widely reported and tick species, respectively. Regardless of species, adult ticks with 2.60% had the highest infection rates, while larvae had the least with 0.60%. Similarly, female ticks with 4.90% were infected compared to males with 3.80%. Nested-polymerase chain reaction (PCR) 2.80% had the highest prevalence among the molecular techniques employed. In conclusion, results obtained indicate that species are present in diverse questing tick species at a low prevalence, of which some are competent vectors.
PubMed: 33669591
DOI: 10.3390/pathogens10020230 -
Veterinary Microbiology Nov 2023Ticks are the main vectors for the transmission of bacterial, protist and viral pathogens in Europe affecting wildlife and domestic animals. However, some of them are... (Review)
Review
Exploring the diversity of tick-borne pathogens: The case of bacteria (Anaplasma, Rickettsia, Coxiella and Borrelia) protozoa (Babesia and Theileria) and viruses (Orthonairovirus, tick-borne encephalitis virus and louping ill virus) in the European continent.
Ticks are the main vectors for the transmission of bacterial, protist and viral pathogens in Europe affecting wildlife and domestic animals. However, some of them are zoonotic and can cause serious, sometimes fatal, problems in human health. A systematic review in PubMed/MEDLINE database was conducted to determine the spatial distribution and host and tick species ranges of a selection of tick-borne bacteria (Anaplasma spp., Borrelia spp., Coxiella spp., and Rickettsia spp.), protists (Babesia spp. and Theileria spp.), and viruses (Orthonairovirus, and flaviviruses tick-borne encephalitis virus and louping ill virus) on the European continent in a five-year period (November 2017 - November 2022). Only studies using PCR methods were selected, retrieving a total of 429 articles. Overall, up to 85 species of the selected tick-borne pathogens were reported from 36 European countries, and Anaplasma spp. was described in 37% (159/429) of the articles, followed by Babesia spp. (34%, 148/429), Borrelia spp. (34%, 147/429), Rickettsia spp. (33%, 142/429), Theileria spp. (11%, 47/429), tick-borne flaviviruses (9%, 37/429), Orthonairovirus (7%, 28/429) and Coxiella spp. (5%, 20/429). Host and tick ranges included 97 and 50 species, respectively. The highest tick-borne pathogen diversity was detected in domestic animals, and 12 species were shared between humans, wildlife, and domestic hosts, highlighting the following zoonotic species: Anaplasma phagocytophilum, Babesia divergens, Babesia microti, Borrelia afzelii, Borrelia burgdorferi s.s., Borrelia garinii, Borrelia miyamotoi, Crimean-Congo hemorrhagic fever virus, Coxiella burnetii, Rickettsia monacensis and tick-borne encephalitis virus. These results contribute to the implementation of effective interventions for the surveillance and control of tick-borne diseases.
Topics: Animals; Humans; Babesia; Encephalitis Viruses, Tick-Borne; Anaplasma; Theileria; Coxiella; Ixodes; Borrelia; Rickettsia; Animals, Domestic; Tick-Borne Diseases; Animals, Wild
PubMed: 37866329
DOI: 10.1016/j.vetmic.2023.109892 -
The Canadian Journal of Infectious... 2020Splenic complications of acute infection include splenomegaly, splenic infarct, and splenic rupture. These complications are relatively rarely reported, and the aim of... (Review)
Review
Splenic complications of acute infection include splenomegaly, splenic infarct, and splenic rupture. These complications are relatively rarely reported, and the aim of this research was to synthetize data on this topic according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the PubMed database. In this review, we find that unlike other severe complications of babesiosis, splenic infarct and rupture occur in younger and immunocompetent patients, and they do not correlate with parasitemia level. Furthermore, admission hemoglobin of 10 mg/dl or less, platelet count of 50 × 10⁹/L or less, presence of hemodynamic instability, and splenic rupture were associated independently with an increased risk of requiring splenectomy. As babesiosis is an emerging tick-borne zoonosis, we hope that this review will help to raise awareness among clinicians regarding this rare but potentially life-threatening complication.
PubMed: 32566058
DOI: 10.1155/2020/6934149 -
Parasites & Vectors Aug 2023Bovine babesiosis, caused by different Babesia spp. such as B. bovis, B. bigemina, B. divergens, and B. major, is a global disease that poses a serious threat to... (Review)
Review
Bovine babesiosis, caused by different Babesia spp. such as B. bovis, B. bigemina, B. divergens, and B. major, is a global disease that poses a serious threat to livestock production. Babesia bovis infections are associated with severe disease and increased mortality in adult cattle, making it the most virulent agent of bovine babesiosis. Babesia bovis parasites undergo asexual reproduction within bovine red blood cells, followed by sexual reproduction within their tick vectors, which transmit the parasite transovarially. Current control methods, including therapeutic drugs (i.e., imidocarb) have been found to lead to drug resistance. Moreover, changing environmental factors add complexity to efficient parasite control. Understanding the fundamental biology, host immune responses, and host-parasite interactions of Babesia parasites is critical for developing next-generation vaccines to control acute disease and parasite transmission. This systematic review analyzed available research papers on vaccine development and the associated immune responses to B. bovis. We compiled and consolidated the reported vaccine strategies, considering the study design and rationale of each study, to provide a systematic review of knowledge and insights for further research. Thirteen studies published since 2014 (inclusive) represented various vaccine strategies developed against B. bovis such as subunit, live attenuated, and viral vector vaccines. Such strategies incorporated B. bovis proteins or whole live parasites with the latter providing the most effective prophylaxis against bovine babesiosis. Incorporating novel research approaches, such as "omics" will enhance our understanding of parasite vulnerabilities.
Topics: Animals; Cattle; Babesia bovis; Babesiosis; Cattle Diseases; Babesia; Vaccines
PubMed: 37563668
DOI: 10.1186/s13071-023-05885-z -
Current Research in Parasitology &... 2022Ticks are significant ectoparasites of animals and humans. Published data indicate that most vectors that transmit livestock and human pathogens in sub-Saharan Africa,... (Review)
Review
Ticks are significant ectoparasites of animals and humans. Published data indicate that most vectors that transmit livestock and human pathogens in sub-Saharan Africa, are native to the region and originate from wild animals. Currently, there is a paucity of information on the role of wild animals on the epidemiology of zoonotic tick-borne pathogens in South Africa. This systematic review focuses on the distribution of ticks and prevalence of tick-borne pathogens in different wild animals in South Africa to identify potential reservoir hosts and possible hotspots for emergence of novel tick-borne pathogens. Following several screening processes, 38 peer-reviewed studies published from 1970 to 2021, were deemed eligible. The studies reported on ticks collected from 63 host species of 21 host families, mostly Canidae, Felidae, Bovidae and Muridae. A total of 49 tick species of nine genera, i.e. , , , , , , , and , were reported. Nine tick species, i.e. , , , , , , . () , and were the most commonly reported. Pathogens of the genera , , and were identified in the wild animals. This review provides more insight on the ecology of ticks and tick-borne pathogens of wild animals in South Africa and gives useful information for predicting their future spread. It also demonstrates that wild animals habour a diverse range of tick species. This level of diversity entails a similarly high potential for emergence of novel tick-borne pathogens. The review further indicates that wild animals in South Africa are sentinels of tick-borne protozoans of veterinary importance and some bacterial pathogens as most ticks they habour are known vectors of pathogens of domestic animals and humans. However, studies on potential tick-borne zoonoses are under-represented and should be included in future epidemiological surveys, especially in the light of climate change and other anthropogenic threats which might result in the emergence of novel tick-borne pathogens.
PubMed: 35601607
DOI: 10.1016/j.crpvbd.2022.100088 -
Ticks and Tick-borne Diseases Jan 2024Published data on tick-borne pathogens (TBPs) in camels worldwide have been collected to provide an overview of the global prevalence and species diversity of camelid... (Meta-Analysis)
Meta-Analysis Review
Published data on tick-borne pathogens (TBPs) in camels worldwide have been collected to provide an overview of the global prevalence and species diversity of camelid TBPs. Several TBPs have been detected in dromedary camels, raising concerns regarding their role as natural or maintenance hosts for tick-borne pathogens. Insubstantial evidence exists regarding the natural infection of camels with Babesia spp., Theileria spp., Anaplasma spp., and Ehrlichia spp., particularly because most of the camels were considered healthy at the time of sampling. Based on polymerase chain reaction (PCR) testing, a pooled prevalence of 35.3% (95% CI: 22.6-48.1%) was estimated for Anaplasma, which was the most frequently tested TBP in dromedaries, and DNA of Anaplasma marginale, Anaplasma centrale, Anaplasma ovis, Anaplasma platys, and A. platys-like were isolated, of which ruminants and dogs are reservoirs. Similarly, the estimated pooled prevalence for the two piroplasmid genera; Babesia and Theileria was approximately equal (10-12%) regardless of the detection method (microscopy or PCR testing). Nevertheless, Babesia caballi, Theileria equi, and Theileria annulata DNA have frequently been detected in camels but they have not yet been proven to be natural hosts. Scarce data detected Babesia microti, Anaplasma phagocytophilum, and Borrelia burgdorferi sensu lato (s.l.) DNA in blood of dromedaries, although ticks of the genus Ixodes are distributed in limited areas where dromedaries are raised. Interestingly, a pooled seroprevalence of 47.7% (26.3-69.2%) was estimated for Crimean-Congo hemorrhagic fever virus, and viral RNA was detected in dromedary blood; however, their contribution to maintain the viral transmission cycles requires further experimental investigation. The substantially low incidence and scarcity of data on Rickettsia and Ehrlichia species could imply that camels were accidentally infected. In contrast, camels may play a role in the spread of Coxiella burnetii, which is primarily transmitted through the inhalation of aerosols emitted by diseased animals and contaminated environments. Bactrian camels showed no symptoms due to the examined TBPs, meanwhile, clinical disease was seen in alpacas infected with A. phagocytophilum. Similar to dromedaries, accidental tick bites may be the cause of TBP DNA found in the blood of Bactrian camels.
Topics: Animals; Dogs; Camelus; Prevalence; Seroepidemiologic Studies; Ehrlichia; Rickettsia; Anaplasma; Babesia; Ixodes; Theileria annulata; DNA; Tick-Borne Diseases; Dog Diseases
PubMed: 37769585
DOI: 10.1016/j.ttbdis.2023.102268 -
Pathogens (Basel, Switzerland) Nov 2020Ticks and tick-borne diseases (TTBDis) are a major constraint to the health and production of small ruminants in Pakistan. Despite being the subject of intermittent... (Review)
Review
Ticks and tick-borne diseases (TTBDis) are a major constraint to the health and production of small ruminants in Pakistan. Despite being the subject of intermittent studies over the past few decades, comprehensive information on the epidemiology and control of TTBDis is lacking. Herein, we have systematically reviewed the current knowledge on TTBDis of small ruminants in Pakistan. Critical appraisal of the selected 71 articles published between 1947 to 2020 revealed that morphological examination had been the most widely used method for the identification of TTBDis in Pakistan. Tick fauna comprise at least 40 species, mainly belonging to , and . The prevalence of ticks is the highest in summer (June-September) and it is also higher in goats than sheep. , and spp. are the major tick-borne pathogens (TBPs), and their prevalence is usually higher in sheep than goats. Spatio-temporal distribution, genetic diversity and control of ticks and TBPs of small ruminants as well as the competence of tick vectors for various TBPs remain to be explored. Therefore, coordinated and focused investigations are required to fill knowledge gaps in these areas to maximise the health, production and welfare of small ruminants and minimise economic losses associated with TTBDis in Pakistan.
PubMed: 33187238
DOI: 10.3390/pathogens9110937 -
Pathogens and Global Health Jun 2022Human babesiosis is an emerging tick-borne protozoan zoonosis caused by parasites of the genus and transmitted by ixodid ticks. It was thought to be a public health... (Meta-Analysis)
Meta-Analysis
Human babesiosis is an emerging tick-borne protozoan zoonosis caused by parasites of the genus and transmitted by ixodid ticks. It was thought to be a public health problem mainly for the immunocompromised, however the increasing numbers of documented cases among immunocompetent individuals is a call for concern. In this systematic review and meta-analysis, we reported from 22 countries and 69 studies, an overall pooled estimate (PE) of 2.23% (95% CI: 1.46-3.39) for infections in humans. PEs for all sub-groups varied significantly (p < 0.05) with a continental range of 1.54% (95% CI: 0.89-2.65) in North America to 4.17% (95% CI: 2.11-8.06) in Europe. PEs for country income levels, methods of diagnosis, study period, sample sizes, species and targeted population ranged between 0.43% (95% CI: 0.41-0.44) and 7.41% (95% CI: 0.53-54.48). recorded the widest geographic distribution and was the predominant specie reported in North America while was predominantly reported in Europe. Eight species; -like, and were reported in humans from different parts of the world with the highest prevalence in Europe, lower middle income countries and among individuals with history of tick bite and other tick-borne diseases. To control the increasing trend of this emerging public health threat, tick control in human settlements, the use of protective clothing by occupationally exposed people and the screening of transfusion blood in endemic countries are recommended. AJOL: African Journals OnLine, CI: Confidence interval, CIL: Country income level, df: Degree of freedom, HIC: Higher-income countries, HQ: High quality, : Inverse variance index, IFAT: Indirect fluorescent antibody test, ITBTBD: Individuals with tick-bite and tick-borne diseases, JBI: Joanna Briggs Institute, LIC: Lower-income countries, LMIC: Lower middle-income countries, MQ: Medium quality, NA: Not applicable, N/America: North America, OEI: Occupational exposed individuals, OR: Odds ratio, PE: Pooled estimates, PCR: Polymerase chain reaction, Prev: Prevalence, PRISMA: Preferred Reporting System for Systematic Reviews and Meta-Analyses, Q: Cochran's heterogeneity statistic, QA: Quality assessment, Q-p: Cochran's p-value, qPCR: Quantitative polymerase chain reaction, S/America: South America, Seq: Sequencing, UMIC: Upper middle-income countries, USA: United States of America.
Topics: Animals; Babesia; Babesiosis; Humans; Prevalence; Tick-Borne Diseases; Zoonoses
PubMed: 34788196
DOI: 10.1080/20477724.2021.1989185 -
Pathogens (Basel, Switzerland) Aug 2022Ticks are hematophagous ectoparasites that are capable of infesting a wide range of mammals, including domestic animals, ruminants, wildlife, and humans across the... (Review)
Review
Epidemiology of Ticks and Tick-Borne Pathogens in Domestic Ruminants across Southern African Development Community (SADC) Region from 1980 until 2021: A Systematic Review and Meta-Analysis.
Ticks are hematophagous ectoparasites that are capable of infesting a wide range of mammals, including domestic animals, ruminants, wildlife, and humans across the world, and they transmit disease-causing pathogens. Numerous individual epidemiological studies have been conducted on the distribution and prevalence of ticks and tick-borne diseases (TBDs) in the Southern African Developing Community (SADC) region, but no effort has been undertaken to synchronize findings, which would be helpful in the implementation of consolidated tick control measures. With the aim of generating consolidated pooled prevalence estimates of ticks and TBDs in the SADC region, we performed a systematic review and meta-analysis of published articles using the PRISMA 2020 guidelines. A deep search was performed on five electronic databases, namely, PubMed, ScienceDirect, Google Scholar, AJOL, and Springer Link. Of the 347 articles identified, only 61 of the articles were eligible for inclusion. In total, 18,355 tick specimens were collected, belonging to the genera , , , and (including ) across several countries, including South Africa (n = 8), Tanzania (n = 3), Zambia (n = 2), Zimbabwe (n = 2), Madagascar (n = 2), Angola (n = 2), Mozambique (n = 1), and Comoros (n = 1). The overall pooled prevalence estimate (PPE) of TBPs in livestock was 52.2%, with the highest PPE in cattle [51.2%], followed by sheep [45.4%], and goats [29.9%]. For bacteria-like and rickettsial TBPs, had the highest PPE of 45.9%, followed by [14.7%], [2.52%], and [0.88%], whilst had a PPE of 4.2%. For piroplasmids, and had PPEs of 20.8% and 20.3%, respectively. had the highest PPE of 43.0%, followed by [29.1%], [25.0%], and other spp. [14.06%]. Findings from this study suggest the need for a consolidated scientific approach in the investigation of ticks, TBPs, and TBDs in the whole SADC region, as most of the TBDs are transboundary and require a regional control strategy.
PubMed: 36015049
DOI: 10.3390/pathogens11080929