Seroprevalence and risk factors for Coxiella burnetii, the causative agent of Q fever in the dromedary camel (Camelus dromedarius) population in Algeria

Serological investigation of Coxiella burnetii infection (Query fever) in livestock in Makkah Province, Saudi Arabia

Background and Aim

Query fever (Q fever) is an endemic zoonotic disease and ruminants are considered to be the primary source of infection in humans. It is caused by Coxiella burnetii which is an obligate intracellular bacterial pathogen with a worldwide distribution. This study estimated the prevalence of Q fever in livestock with a history of abortion in Makkah Province, Saudi Arabia.

Material and Methods

Sera from 341 camels, 326 sheep, and 121 goats of either sex from various locations (Makkah, Jeddah, AL-Taif, AL-Qunfudah, AL-Laith, and AL-Kamil) were examined using a Q fever indirect enzyme-linked immunosorbent assay.

Results

Among the 788 serum samples, 356 animals had anti-Coxiella burnetii immunoglobulin G antibodies with an overall seroprevalence of 45.4%. Significant differences were observed in seroprevalence between species and locations. Camels had the highest percentage of Q fever-positive sera, with a prevalence of 50.4%, followed by goats (44.6%) and sheep (36.8%), with a high significant difference between animals (p = 0.000). The prevalence was significantly higher in Makkah (65.4%) than in Jeddah (28.8%).

Conclusion

C. burnetii infection is prevalent in agricultural animals, especially camels maintained at livestock farms in Makkah province. Therefore, these animals considered as the main source of Q fever infections in Saudi Arabia, which is also a reason for the abortion in these animals. Therefore, there is an urgent need for further studies on Q fever infection with interventional approaches for prevention and control.

Molecular detection and MST genotyping of Coxiella burnetii in ruminants and stray dogs and cats in Northern Algeria

Aiming at identifying the reservoir and contamination sources of Coxiella burnetii in Northern Algeria, we investigated the molecular presence of the bacterium in 599 samples (blood, placenta, liver, spleen, and uterus) collected from cattle, sheep, dogs and cats. Our qPCR results showed that 15/344 (4.36%) blood samples and six/255 (2.35%) organ specimens were positive for C. burnetii. In cattle, three (4%) blood and liver samples were positive. In sheep, one blood (1.19%) and 3 (8.57%) placenta samples were positive. At the Algiers dog pound, 8 (10%) and 3 (5%) blood samples were qPCR positivein dogs and cats, respectively. In addition, MST genotyping showed that MST 33 was present in cattle and sheep, MST 20 in cattle,andMST 21 in dogs and cats.

Tick-borne pathogens in camels: A systematic review and meta-analysis of the prevalence in dromedaries

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.

Antibody-Based Assessment of Coxiella burnetii Circulation in Algerian Goat Herds

Q fever is a zoonotic disease caused by Coxiella burnetii (C. burnetii), a pathogen with a high capability for infection. The disease primarily affects ruminants, leading to reproductive disorders, but can also be transmitted to humans through contact with infected animals or their products. In Algeria, Q fever is endemic, but little is known about the presence and circulation of C. burnetii in domestic goats. This study aimed to perform a multicentric serological analysis of C. burnetii antibodies in domestic goats from four provinces in the North East Region of Algeria. A total of 504 goat serum samples were collected from 77 herds, and serological analysis was performed using an indirect ELISA. The overall seroprevalence at the herd level was 35.06%, and 8.73% at the individual level. Herds with a history of abortions showed a high seropositivity rate of 88.9%. This research indicates the wide distribution of C. burnetii in goats in this region, suggesting the potential for zoonotic transmission to humans. Further studies and monitoring programs are essential to gain a comprehensive understanding of C. burnetii epidemiology in Algeria and to prevent or mitigate potential outbreaks. Awareness among practitioners and farmers is crucial to address this public health concern effectively.

Molecular detection of Coxiella burnetii in raw meat samples collected from different abattoirs in districts Kasur and Lahore of Punjab, Pakistan

Coxiella burnetii is the zoonotic pathogen that causes Q fever; it is widespread globally. Livestock animals are its main reservoir, and infected animals shed C. burnetii in their birth products, feces, vaginal mucus, urine, tissues, and food obtained from them, i.e., milk and meat. There were previously very few reports on the prevalence of C. burnetii in raw meat. This study aimed to determine the prevalence of C.burnetii and its molecular characterization in raw ruminant meat from the Kasur and Lahore districts in Punjab, Pakistan, as this has not been reported so far. In this study, 200 meat samples, 50 from each species of cattle, buffalo, goat, and sheep, were collected from the slaughterhouses in each district, Kasur and Lahore in 2021 and 2022. PCR was used for the detection of the IS1111 element of C. burnetii. The data were recorded and univariate analysis was performed to determine the frequency of C. burnetii DNA in raw meat samples obtained from different ruminant species using the SAS 9.4 statistical package. Of the total of 200 raw meat samples, C. burnetii DNA was present in 40 (20%) of them, tested by PCR using the IS1111 sequence. The prevalence of C.burnetii differed among the studied species of ruminants. When species were compared pairwise, the prevalence in cattle was statistically significantly lower than in sheep (P = 0.005). The sequence alignment based on origin implied that the strains are genetically diverse in different districts of Punjab, Pakistan. The findings demonstrated that the prevalence of C. burnetii, especially in raw meat samples, deserves more attention from the health care system and professionals from Punjab, Pakistan, i.e., abattoir workers and veterinarians.

Human-biting ticks and zoonotic tick-borne pathogens in North Africa: diversity, distribution, and trans-Mediterranean public health challenges

North Africa is home to more than 200 million people living across five developing economies (Egypt, Libya, Tunisia, Algeria, and Morocco) and two Spanish exclaves (Ceuta and Melilla), many of whom are impacted by ticks and tick-borne zoonoses. Populations in Europe are also increasingly vulnerable to North African ticks and tick-borne zoonoses due to a combination of climate change and the movement of ticks across the Mediterranean on migratory birds, human travellers, and trafficked wildlife. The human-biting ticks and tick-borne zoonoses in North Africa are reviewed along with their distribution in the region. We also assess present and future challenges associated with ticks and tick-borne zoonoses in North African and highlight opportunities for collaboration and coordination between governments in Europe and North Africa to address public health challenges posed by North African ticks and tick-borne zoonoses.

Prevalence and risk factors of Q fever (Coxiella burnetii) in cattle on farms of Limpopo province, South Africa

Q fever in animals and humans and its economic and public health significance has been widely reported worldwide but in South Africa. There are few studies on the prevalence of this zoonosis and its associated risk factors in South African livestock. Therefore, a cross-sectional study was conducted to determine the seroprevalence, molecular prevalence, and risk factors associated with C. burnetii in cattle on farms in South Africa's Limpopo province. Out of 383 cattle tested for antibodies, the overall seroprevalence was 24.28%. Herd size of >150 (OR: 9.88; 95%CI: 3.92-24.89; p < 0.01) remained associated with C. burnetii seropositivity in cattle. For PCR detection, targeting IS1111 fragment, cattle with no abortion history (OR: 0.37; 95%CI: 0.18-0.77; p < 0.01) and herd size of >150 (OR: 3.52; 95%CI: 1.34-9.24; p < 0.01) remained associated with C. burnetii positivity. The molecular prevalence in sheath scrapings and vaginal swabs by IS1111 PCR was 15.67%. Cohen's kappa agreement test revealed a fair agreement between the PCR and ELISA results (k = 0.40). Sequence analysis revealed that the amplicons had similarities to the C. burnetii transposase gene fragment, confirming the presence of the pathogen. The higher seroprevalence than molecular prevalence indicated a past C. burnetii infection, no bacterial shedding through vaginal mucus in cows, or preputial discharge in bulls. Similarly, the detection of C. burnetii by PCR in the absence of antibodies could be partly explained by recent infections in which antibodies have not yet been produced against the bacteria, or the level of these antibodies was below the detectability threshold. The presence of the pathogen in cattle and the evidence of exposure, as shown by both PCR and ELISA suggests an active circulation of the pathogen. This study demonstrated that C. burnetii is widespread in the study area and that a herd size of >150 is associated with C. burnetii seroprevalence and molecular prevalence.

Seropositivity for Coxiella burnetii in Wild Boar (Sus scrofa) and Red Deer (Cervus elaphus) in Portugal

Q fever is caused by the pathogen Coxiella burnetii and is a zoonosis that naturally infects goats, sheep, and cats, but can also infect humans, birds, reptiles, or arthropods. A survey was conducted for the detection of antibodies against C. burnetii in a sample of 617 free-ranging wild ruminants, 358 wild boar (Sus scrofa) and 259 red deer (Cervus elaphus), in east–central Portugal during the 2016–2022 hunting seasons. Only adult animals were sampled in this study. Antibodies specific to C. burnetii were detected using a commercial enzyme-linked immunosorbent assay (ELISA; IDVet®, Montpellier, France) according to the manufacturer’s instructions. The seroprevalence of C. burnetii infection was 1.5% (n = 9; 95% confidence interval [CI]: 0.7–2.8%). Antibodies against C. burnetii were detected in 4/358 wild boar (1.1%; 95% CI: CI: 0.3–2.8%) and 5/259 red deer (1.9%; 0.6–4.5%). Results of the present study indicate that antibodies against C. burnetii were present in wild boar and red deer in Portugal. These findings can help local health authorities to focus on the problem of C. burnetii in wildlife and facilitate the application of a One Health approach to its prevention and control.

Coxiella burnetii in ticks, livestock, pets and wildlife: A mini-review

Coxiella burnetii is a zoonotic bacterium with an obligatory intracellular lifestyle and has a worldwide distribution. Coxiella burnetii is the causative agent of Q fever in humans and coxiellosis in animals. Since its discovery in 1935, it has been shown to infect a wide range of animal species including mammals, birds, reptiles, and arthropods. Coxiella burnetii infection is of public and veterinary health and economic concern due to its potential for rapid spread and highly infectious nature. Livestock are the primary source of C. burnetii infection in most Q fever outbreaks which occurs mainly through inhalation of contaminated particles. Aside from livestock, many cases of Q fever linked to exposure to wildlife. Changes in the dynamics of human-wildlife interactions may lead to an increased potential risk of interspecies transmission and contribute to the emergence/re-emergence of Q fever. Although C. burnetii transmission is mainly airborne, ticks may act as vectors and play an important role in the natural cycle of transmission of coxiellosis among wild vertebrates and livestock. In this review, we aim to compile available information on vectors, domestic, and wild hosts of C. burnetii, and to highlight their potential role as bacterial reservoirs in the transmission of C. burnetii.

Endemicity of Coxiella burnetii infection among people and their livestock in pastoral communities in northern Kenya

Background

Coxiella burnetti can be transmitted to humans primarily through inhaling contaminated droplets released from infected animals or consumption of contaminated dairy products. Despite its zoonotic nature and the close association pastoralist communities have with their livestock, studies reporting simultaneous assessment of C. burnetti exposure and risk-factors among people and their livestock are scarce.

Objective

This study therefore estimated the seroprevalence of Q-fever and associated risk factors of exposure in people and their livestock.

Materials and methods

We conducted a cross-sectional study in pastoralist communities in Marsabit County in northern Kenya. A total of 1,074 women and 225 children were enrolled and provided blood samples for Q-fever testing. Additionally, 1,876 goats, 322 sheep and 189 camels from the same households were sampled. A structured questionnaire was administered to collect individual- and household/herd-level data. Indirect IgG ELISA kits were used to test the samples.

Results

Household-level seropositivity was 13.2% [95% CI: 11.2–15.3]; differences in seropositivity levels among women and children were statistically insignificant (p = 0.8531). Lactating women had higher odds of exposure, odds ratio (OR) = 2.4 [1.3–5.3], while the odds of exposure among children increased with age OR = 1.1 [1.0–1.1]. Herd-level seroprevalence was 83.7% [81.7–85.6]. Seropositivity among goats was 74.7% [72.7–76.7], while that among sheep and camels was 56.8% [51.2–62.3] and 38.6% [31.6–45.9], respectively. Goats and sheep had a higher risk of exposure OR = 5.4 [3.7–7.3] and 2.6 [1.8–3.4], respectively relative to camels. There was no statistically significant association between Q-fever seropositivity and nutrition status in women, p = 0.900 and children, p = 1.000. We found no significant association between exposure in people and their livestock at household level (p = 0.724) despite high animal exposure levels, suggesting that Q-fever exposure in humans may be occurring at a scale larger than households.

Conclusion

The one health approach used in this study revealed that Q-fever is endemic in this setting. Longitudinal studies of Q-fever burden and risk factors simultaneously assessed in human and animal populations as well as the socioeconomic impacts of the disease and further explore the role of environmental factors in Q-fever epidemiology are required. Such evidence may form the basis for designing Q-fever prevention and control strategies.

Epidemiology and genetic characteristics of tick-borne bacteria in dromedary camels of the world

This review presents updated knowledge on the main tick-borne bacteria infecting one-humped camels (Camelus dromedarius) around the world. Camels are increasingly the subject of several scientific investigations, showing that they are receptive and carriers of several zoonotic bacteria. An appraisal is also given of the relative public health importance of these bacterial infections according to One Health concept. Microscopic, serologic and molecular findings are appropriately generated in order to exploit epidemiological data, and phylogeographic specificities associated to each vector-borne bacterium. Indeed, camels and their ticks harbour similar species and genotypes of pathogenic bacteria commonly identified in other animals, e.g., Anaplasma spp.,Ehrlichia spp., Borrelia spp., Rickettsia spp., Coxiella burnetii, Bartonella spp. and hemotrophic mycoplasmas. This evidence suggests an epidemiological role of camels in the spread of these pathogens in their natural habitats. However, these infections are commonly asymptomatic in camels resulting in underestimation of the impact of these infections. Furthermore, camels have recently been proven to have their own specific unclassified strains, such as Candidatus Anaplasma camelii and Candidatus Bartonella camelii, implying that possible interactions may lead to the emergence of pathogenic and zoonotic bacteria. In camel-rearing areas of the world, spatial and temporal spread of these infections, due to climatic and ecological changes and human activities such as development projects and urbanization, is expected. Hence the data presented herein provides a basis for strategic frameworks for the research and the development of novel diagnosis and control strategies worldwide, which are needed to protect camels, other livestock, and people in contact with dromedaries from threats that arthropod-borne pathogens can pose.

Seroprevalence and Molecular Evidence of Coxiella burnetii in Dromedary Camels of Pakistan

Coxiellosis is a zoonosis in animals caused by Coxiella burnetii. A cross-sectional study was conducted on 920 (591 female and 329 male) randomly selected camels (Camelus dromedarius) of different age groups from 13 districts representative of the three different ecological zones in the Province Punjab, Pakistan to determine the prevalence and associated risk factors of coxiellosis. The blood samples were collected and tested for anti-C. burnetti antibodies using indirect multispecies ELISA. Real-time PCR was used for the detection of C. burnetii DNA to determine the prevalence in heparinized blood pools. Out of 920 investigated camels, anti-C. burnetii antibodies were detected in 288 samples (31.3%) (95% CI: 28.3–34.4%). The highest (78.6%) and lowest (1.8%) seroprevalence were detected in Rahimyar Khan (southern Punjab) and in Jhang (central Punjab), respectively. Potential risk factors associated with seropositivity of the Q fever in camels included desert area (42.5%; OR = 2.78, 95% CI 1.12–3.21) summer season (35.7%; OR = 2.3, 95% CI: 1.31–3.2), sex (female) (39.1; OR = 2.35, 95% CI: 1.34–2.98), tick infestation (51.3%;OR = 2.81, 95% CI: 1.34–3.02), age (>10 years; 46.4%; OR = 1.56, 95% CI: 0.33–2.05) and herd size (38.5%; OR = 1.21, 95% CI: 0.76–1.54). Coxiella burnetii DNA was amplified in 12 (20%) and 1 (10%) of 60 ELISA-negative and 10 suspected camels, respectively. DNA could not be detected in ELISA positive blood pools. This study emphasizes the seroprevalence and associated risk factors of coxiellosis as well as its potential to spill over to animals and humans in contact with these camel herds.

Distribution of Tick-Borne Pathogens in Domestic Animals and Their Ticks in the Countries of the Mediterranean Basin between 2000 and 2021: A Systematic Review

Tick-borne pathogens (TBPs) include a wide range of bacteria, parasites and viruses that cause a large spectrum of animal, human and zoonotic tick-borne diseases (TBDs). The object of this review was to establish an inventory and an analysis of TBPs found in domestic animals in the countries of the Mediterranean Basin. This geographic area occupies a central position between several continents and is an area of movement for animals, humans and pathogens of interest and their vectors, which is important in terms of animal and human health. In this systematic review, we included a total of 271 publications produced between 2000–2021 concerning TBPs in domestic animals. Among this literature, we found a total of 90 pathogen species (known as TBPs) reported in the 20 countries of the area; these were detected in tick species from domestic animals and were also directly detected in domestic animals. In all, 31 tick species were recorded and 12 domestic animal species, the latter comprising nine livestock and three pet species. More than 50% of the publications were from Western Europe. Island data were extracted and assessed, as islands of the Mediterranean Basin were represented in 16% of the publications and 77.8% of the TBPs reported. Our results show the importance of islands in the monitoring of TBPs, despite the low percentage of publications.

Phenology and phylogeny of Hyalomma spp. ticks infesting one-humped camels (Camelus dromedarius) in the Tunisian Saharan bioclimatic zone

In this study, we report the results of a survey of Hyalomma ticks infesting one-humped camels in southern Tunisia. Examinations were conducted every second or third month on 406 camels in Tataouine district from April 2018 to October 2019. A total of 1902 ticks belonging to the genus Hyalomma were collected. The ticks were identified as adult H. impeltatum (41.1%; n = 782), H. dromedarii (32.9%; n = 626), H. excavatum (25.9%; n = 493), and H. marginatum for a single specimen. Although the camels were infested by ticks throughout the year, the highest overall infestation prevalence was observed in April 2018 (p < 0.01). The overall infestation intensity varied between 2.7 and 7.4 ticks/animal. There were no statistically significant differences in tick infestation prevalence based on age categories of the camels, and the overall infestation prevalence was between 82.7% and 97.4%. Female camels were significantly more infested with ticks (88.3%) than males (65.5%) (p < 0.01). The infestation prevalence of camels varied significantly according to the region where sampling took place (p < 0.01), but no correlations were found with abiotic factors. The preferred attachment sites for adult Hyalomma ticks were the sternum (38.3%; n = 729/1902), around the anus (36.2%; n = 689/1902), udder (18.4%; n = 350/1902), and inner thigh (6.9%; n = 132/1902). Morphological classification of ticks was corroborated by sequencing the cytochrome c oxidase I (Cox1) and 16S rDNA genes, and these sequences were also used to infer phylogenetic relationships. A single H. dromedarii seemed to be a natural hybrid with H. rufipes. More attention should be devoted by the veterinary services to the infestation of camels by ticks.

Evaluation of three immunological assays to mitigate the risk of transboundary spread of Coxiella burnetii by alpacas

Coxiella burnetii causes coxiellosis in animals and Q fever in humans, a potentially debilitating zoonotic disease commonly transmitted through domestic ruminants. To prevent transboundary spread of C. burnetii, animals may be tested prior to export. In alpacas, this process is complicated by the lack of scientific evidence for C. burnetii infection in the species, and the unique composition of camelid antibodies, which may cause false-positive results in assays developed for ruminants. We evaluated a complement fixation test (CFT; currently recommended for alpacas in New Zealand), an enzyme-linked immunosorbent assay (ELISA) and an immunofluorescence assay (IFA). Positive analytical control samples were generated through vaccination of alpacas with a human Q fever vaccine, whereas negative analytical control samples were sourced from New Zealand (deemed free of C. burnetii). Immunological assays were conducted on 131 alpaca sera submitted for export testing. Test characteristics (sensitivity, specificity, positive and negative predictive values) for CFT, ELISA and IFA were determined using Bayesian latent class analysis. Due to anticomplementary activity, 37 (28.2%) of the CFT results were inconclusive, making CFT unsuitable for routine use. Of the remaining 94 samples, 10.6%, 0% and 7.4% were positive for C. burnetii antibodies based on CFT, ELISA and IFA, respectively, yielding estimated sensitivities of 58%, 26% and 78%, and estimated specificities of 95%, 98% and 95%, with the estimates for sensitivity being imprecise, as evidenced by wide 95% credible intervals. Positive predictive values were similar across assays, albeit very low at the estimated seroprevalence of 5%. Our results indicate that, of the tests available, IFA appears to be the most appropriate for use in alpacas. Higher sensitivity of antibody detection, use of antigen detection assays and availability of samples from individuals with evidence of infection could provide additional insight into the risk of transboundary spread of C. burnetii by alpacas.

Phylogeography of Human and Animal Coxiella burnetii Strains: Genetic Fingerprinting of Q Fever in Belgium

Q fever is a zoonotic disease caused by the bacteria Coxiella burnetii. Domestic ruminants are the primary source for human infection, and the identification of likely contamination routes from the reservoir animals the critical point to implement control programs. This study shows that Q fever is detected in Belgium in abortion of cattle, goat and sheep at a different degree of apparent prevalence (1.93%, 9.19%, and 5.50%, respectively). In addition, and for the first time, it is detected in abortion of alpaca (Vicugna pacos), raising questions on the role of these animals as reservoirs. To determine the relationship between animal and human strains, Multiple Locus Variable-number Tandem Repeat Analysis (MLVA) (n=146), Single-Nucleotide Polymorphism (SNP) (n=92) and Whole Genome Sequencing (WGS) (n=4) methods were used to characterize samples/strains during 2009-2019. Three MLVA clusters (A, B, C) subdivided in 23 subclusters (A1-A12, B1-B8, C1-C3) and 3 SNP types (SNP1, SNP2, SNP6) were identified. The SNP2 type/MLVA cluster A was the most abundant and dispersed genotype over the entire territory, but it seemed not responsible for human cases, as it was only present in animal samples. The SNP1/MLVA B and SNP6/MLVA C clusters were mostly found in small ruminant and human samples, with the rare possibility of spillovers in cattle. SNP1/MLVA B cluster was present in all Belgian areas, while the SNP6/MLVA C cluster appeared more concentrated in the Western provinces. A broad analysis of European MLVA profiles confirmed the host-species distribution described for Belgian samples. In silico genotyping (WGS) further identified the spacer types and the genomic groups of C. burnetii Belgian strains: cattle and goat SNP2/MLVA A isolates belonged to ST61 and genomic group III, while the goat SNP1/MLVA B strain was classified as ST33 and genomic group II. In conclusion, Q fever is widespread in all Belgian domestic ruminants and in alpaca. We determined that the public health risk in Belgium is likely linked to specific genomic groups (SNP1/MLVA B and SNP6/MLVA C) mostly found in small ruminant strains. Considering the concordance between Belgian and European results, these considerations could be extended to other European countries.

Sero-prevalence of brucellosis, Q-fever and Rift Valley fever in humans and livestock in Somali Region, Ethiopia

Information on zoonotic diseases in humans and livestock are limited in pastoral/agro-pastoral communities in Ethiopia. A multi-stage cross sectional cluster design study was implemented with the aim to establish the seroprevalence of zoonotic diseases including brucellosis, Q-fever and Rift Valley fever (RVF) in humans and livestock in Adadle Woreda of the Somali Region, Ethiopia. Blood samples were collected from humans and livestock and tested by relevant serological tests. For brucellosis, Rose Bengal test (RBT) and indirect ELISA was used for screening and confirmatory diagnosis respectively. Indirect and competitive ELISA were also used for Q-fever and RVF respectively. The individual seropositivity of Q-fever in livestock was 9.6% (95% CI 5.9-15.1) in cattle, 55.7% (95% CI 46.0-65.0) in camels, 48.8% (95% CI 42.5-55.0) in goats, and 28.9% (95% CI 25.0-33.2) in sheep. In humans, seropositivity of Q-fever was 27.0% (95% CI 20.4-34.0), with prevalence in males of 28.9% vs 24.2% in females (OR = 1.3; 95% CI 0.6-2.5). Camel seropositivity of Q-fever was significantly associated with age (OR = 8.1; 95% CI 2.8-23.7). The individual apparent seroprevalence of RVF was 13.2% (95% CI 8.7-18.8) in humans, 17.9% (95% CI 11.0-27.8) in cattle, 42.6% (95% CI 34.8-50.7) in camels, 6.3% (95% CI 3.3-11.6) in goats and 7.4% (95% CI 4.7-11.5) in sheep. Camels had the highest seropositivity of both Q-fever and RVF. Only a weak correlation was observed between human and livestock seropositivity for both Q-fever and RVF. Only cattle and camels were seropositive for brucellosis by iELISA. The individual seroprevalence of brucellosis was 2.8(0.9-6.4) in humans, 1.5% (95% CI 0.2-5.2) in cattle and 0.6% (95% CI 0.0-3.2) in camels. This study showed the importance of zoonoses in Somali Region and is the first published study to describe RVF exposure in humans and livestock in the country. Even though human exposure to RVF virus was reported, public health sector of Somali Region has not given attention to such zoonoses. Collaboration between public and animal health sectors for further investigation on these zoonoses using the One Health concept is indispensable.

Coxiella burnetii in Dromedary Camels (Camelus dromedarius): A Possible Threat for Humans and Livestock in North Africa and the Near and Middle East?

The "One Health" concept recognizes that human health is connected to animal health and to the ecosystems. Coxiella burnetii-induced human Q fever is one of the most widespread neglected zoonosis. The main animal reservoirs responsible for C. burnetii transmission to humans are domesticated ruminants, primarily goats, sheep, and cattle. Although studies are still too sparse to draw definitive conclusions, the most recent C. burnetii serosurvey studies conducted in herds and farms in Africa, North Africa, Arabian Peninsula, and Asia highlighted that seroprevalence was strikingly higher in dromedary camels (Camelus dromedarius) than in other ruminants. The C. burnetii seroprevalence in camel herds can reach more than 60% in Egypt, Saudi Arabia, and Sudan, and 70 to 80% in Algeria and Chad, respectively. The highest seroprevalence was in female camels with a previous history of abortion. Moreover, C. burnetii infection was reported in ticks of the Hyalomma dromedarii and Hyalomma impeltatum species collected on camels. Even if dromedary camels represent <3% of the domesticated ruminants in the countries of the Mediterranean basin Southern coast, these animals play a major socioeconomic role for millions of people who live in the arid zones of Africa, Middle East, and Asia. In Chad and Somalia, camels account for about 7 and 21% of domesticated ruminants, respectively. To meet the growing consumers demand of camel meat and milk (>5 million tons/year of both raw and pasteurized milk according to the Food and Agriculture Organization) sustained by a rapid increase of population (growth rate: 2.26-3.76 per year in North Africa), dromedary camel breeding tends to increase from the Maghreb to the Arabic countries. Because of possible long-term persistence of C. burnetii in camel hump adipocytes, this pathogen could represent a threat for herds and breeding farms and ultimately for public health. Because this review highlights a hyperendemia of C. burnetii in dromedary camels, a proper screening of herds and breeding farms for C. burnetii is urgently needed in countries where camel breeding is on the rise. Moreover, the risk of C. burnetii transmission from camel to human should be further evaluated.

First report of Chlamydophila abortus infection in the dromedary camel (Camelus dromedarius) population in eastern Algeria

Chlamydiosis is caused by an obligate intracellular gram-negative bacterium of the genus Chlamydophila which is a zoonotic pathogen. The objectives of the study were to identify the seroprevalence of antibodies against Chlamydophila abortus in dromedary camel herds from four districts in eastern Algeria, as well as to estimate the association between seroprevalence and certain factors present at the animal and herd levels. Blood samples were collected from a random sample of animals within each of 82 camel herds. Serum samples were subjected to a C. abortus ELISA test, and association between the presence of antibodies and potential risk factors was estimated. Animal and herd seroprevalence were 2.5 % and 15.8 %, respectively, indicating substantial exposure of camels to C. abortus in the four districts studied. Age, breed, and sex did not influence seroprevalence in tested animals. Based on the univariate analysis, contact with sheep and goats, contact with other camel herds, and histories of abortion were major risk factors for infection. By using multivariate analysis, contact of camels with sheep and goats and with others camel herds, through shared grazing or watering points, were important factors for transmission of chlamydiosis with an odds ratio of 3.3 and 9.4, respectively. At the herd level the introduction of purchased animals was the major risk factor. This baseline information will be highly useful for launching C. abortus control programs in the region and potentially elsewhere.

Assessment of Trypanosoma evansi prevalence and associated risk factors by immune trypanolysis test in camels from Ghardaïa district, southern Algeria

Trypanosoma evansi (T. evansi) is a flagellated parasite with worldwide distribution, mainly affecting camels, horses, dogs, buffaloes and wild animals. Trypanosomosis caused by T. evansi, known as surra, is a vector borne disease that affects the health and productivity of camels. The aim of our study was to assess the prevalence of trypanosomosis due to T. evansi in camels by the immune trypanolosis test and to identify associated risk factors. Our cross-sectional study was performed on 161 camels from Ghardaïa district, southern Algeria. A structured questionnaire was used to collect data on individual characteristics (age, gender and breed) husbandry management (herd size and activity of animals) and health conditions (history of abortion and clinical symptoms). The immune trypanolysis test revealed an overall seroprevalence of 9.3% (CI 95%, 5.9-14.9). Possible factors associated with T. evansi infection were analysed by univariate and multivariate logistic regression. The results showed that risk factors for camels were history of symptoms (P = 0.002, OR = 21.91, CI95% = 3.48-169.80), racing activities (P = 0.003, OR = 0.01, CI95% = 0.001-0.18) and small herd size (P = 0.013, OR = 8.22, CI95% = 1.64-49.75). In conclusion, this study showed that T. evansi is endemic in camels of Ghardaïa district. To reduce dissemination of the disease to non-endemic areas, it is recommended to minimise risk factors associated with the infection.

Seroprevalence and risk factors for C. burentii infection in camels in Egypt

Q fever caused by Coxiella burentii, gram negative obligate intracellular bacterium. The disease has been reported in wide range of animals especially ruminants. The available data about the prevalence of Q fever in camels in Egypt are limited. Therefore, the present study aimed to investigate the seroprevalence of C. burnetii among camels and identify the risk factors associated with infection. A total 315 serum samples were collected from three governorates in Egypt during 2018 and examined by an indirect Enzyme linked Immunosorbent Assay (ELISA). The obtained results were subsequent analyzed by chi-square and logistic regression. Generally, the seroprevalence of C. burnetii among camels was 22 %. The results revealed that the seroprevalence of C. burnetii increased in aged female camels in comparison with young one and was higher also in female with history of abortion (OR = 4.6, 95%CI: 2.46-8.76). The infection was significantly increased during autumn season (OR = 9.3, 95%CI: 4.23-20.5). Besides, camels in contact with small ruminants showed high level of infection (OR = 1.12, 95%CI: 0.65-1.93) or camel with heavy tick infestation (OR = 1.08, 95%CI: 0.60-1.92). Our report confirms that the seroprevalence of C. burnetii among camels in Egypt and appropriate control measures should be taken to reduce the transmission of infection to other animal species or human.

Considerations for the development of a dromedary camel (Camelus dromedarius) semen collection centre

The dromedary camel (DC) is a strategic animal for the exploitation of the desert and unhospitable lands (arid and semiarid areas). These animals are a genetic resource, locally adapted and more resilient to these environs, that may significantly contribute to food security and sustainable development of marginal land areas. Artificial insemination is the least invasive, least expensive technique for improving genetic selection and minimising transmission of venereal disease among animals and herds. Besides semen preservation protocols, specific approaches for the development of DC semen collection centres - biosecurity measures, screening for infectious diseases, management of animals, welfare, nutrition, control of seasonality, training, hygiene of semen collection and processing - have been considered less important aspects. The aim of this research is to describe the aspects related to the development of a DC semen collection centre, summarising the latest studies in the field of welfare, reproduction and diseases, and describing biosecurity and hygiene aspects related to semen collection and handling. Scientific gaps and requirements for maximising the production of good quality and safe-to-use semen doses with minimal risks of disease transmission are also described.

Coxiella burnetii in Tunisian dromedary camels (Camelus dromedarius): Seroprevalence, associated risk factors and seasonal dynamics

Q fever, caused by Coxiella burnetii, is a zoonotic disease responsible of abortion in ruminants. Few studies have investigated the prevalence of this infection in camels (Camelus dromedarius). The present report aimed to highlight the epidemiological status and identify the risk factors associated with C. burnetii infection in one-humped dromedary that is the most productive livestock species in arid areas. A total of 534 sera of healthy camels were collected in eight governorates from southern and central Tunisia. Samples were tested by an indirect Enzyme linked Immunosorbent Assay (ELISA). Results were analyzed using the Chi-square test and logistic regression. Overall, 237 camels (44%, 95%CI: 0.40-0.49) were seropositive to C. burnetii. Statistical analysis pointed out four potential risk factors associated with infection. A meaningful high seropositivity was observed in female camels with a previous history of abortion (70%) (OR = 4.186, 95%CI: 2.05-8.51). Seroprevalence was higher in aged camels (>10 years-old) (48%) (OR = 2.91, 95%CI: 1.37-6.17). Besides, camels, intended for meat production from small herds showed a high level of infection (52%) (OR = 2.43, 95%CI: 1.3-4.5). Coxiellosis evolved in dromedary herds throughout the year, however infection was significantly important in autumn (60%) (OR = 4.13, 95%CI: 1.86-9.17) and winter (56%) (OR = 5.52, 95%CI: 2.50-12.16). Bioclimatic stage, gender, tick infestation and contact with other ruminants were not risk factors in camel's infection by C. burnetii. Our reports confirm that Tunisian one-humped dromedaries had been exposed to this bacterium and could contribute to its dissemination among farmers and other livestock animals. Furthers studies are required to evaluate the prevalence of Q fever among people professionally exposed like farmers, veterinarians and slaughterhouse workers.

Body lice of homeless people reveal the presence of several emerging bacterial pathogens in northern Algeria

BACKGROUND

Human lice, Pediculus humanus, are obligate blood-sucking parasites. Body lice, Pediculus h. humanus, occur in two divergent mitochondrial clades (A and D) each exhibiting a particular geographic distribution. Currently, the body louse is recognized as the only vector for louse-borne diseases. In this study, we aimed to study the genetic diversity of body lice collected from homeless populations in three localities of northern Algeria, and to investigate louse-borne pathogens in these lice.

METHODOLOGY/PRINCIPAL FINDINGS

In this study, 524 body lice specimens were collected from 44 homeless people in three localities: Algiers, Tizi Ouzou and Boumerdès located in northern Algeria. Duplex clade specific real-time PCRs (qPCR) and Cytochrome b (cytb) mitochondrial DNA (mtDNA) analysis were performed in order to identify the mitochondrial clade. Screening of louse-borne pathogens bacteria was based on targeting specific genes for each pathogen using qPCR supplemented by sequencing. All body lice belong to clade A. Through amplification and sequencing of the cytb gene we confirmed the presence of three haplotypes: A5, A9 and A63, which is novel. The molecular investigation of the 524 body lice samples revealed the presence of four human pathogens: Bartonella quintana (13.35%), Coxiella burnetii (10.52%), Anaplasma phagocytophilum (0.76%) and Acinetobacter species (A. baumannii, A. johnsonii, A. berezeniae, A. nosocomialis and A. variabilis, in total 46.94%).

CONCLUSIONS/SIGNIFICANCE

To the best of our knowledge, our study is the first to show the genetic diversity and presence of several emerging pathogenic bacteria in homeless' body lice from Algeria. We also report for the first time, the presence of several species of Acinetobacter in human body lice. Our results highlight the fact that body lice may be suspected as being a much broader vector of several pathogenic agents than previously thought. Nevertheless, other studies are needed to encourage epidemiological investigations and surveys of louse-associated infections.