A survey of the tick-borne disease Crimean-Congo hemorrhagic fever in southern Algeria: First serological evidence in the dromedary camel population.

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral zoonosis caused by a Nairovirus, Crimean-Congo hemorrhagic fever virus (CCHFV). Despite its wide geographical distribution, the epidemiology of CCHF in northern Africa is incompletely understood and its occurrence in Algeria is virtually unknown. The present survey aimed to determine the prevalence of CCHF antibodies and to identify the potential risk factors associated with CCHFV seropositivity among the one-humped camel (Camelus dromedarius) in southern Algeria. A total of 269 camels selected randomly from slaughterhouses in three wilayas were employed in the study. Sera sampled were tested for the presence of CCHFV-specific IgG antibodies using enzyme-linked immunosorbent assay (ELISA). CCHFV seropositivity was recorded in 255 out of 269 camels accounting for a prevalence rate of 94.8% (95%CI = 92.14-97.45). The seroprevalence by origin was determined to be 97% (193/199) in imported camels and 86% (49/57) in local ones (p > 0.25). Tick presence (OR = 12.35, 95%CI = 1.41-107.43, p < 0.05) was recorded as the only potential risk factor for contracting CCHFV. This study shows for the first time that camels are exposed to CCHFV in Algeria with a significantly high seroprevalence. It also underlines the need for further research to investigate the broader extent of circulating CCHFV in the country, whether in humans, animals, or ticks.

Prevalence and associated risk factors of anti-Coxiella burnetii antibodies in dairy cattle herds using bulk tank milk analysis in Kabylia area, north Algeria.

Coxiella burnetii, or Q fever agent, has notable implications for human and livestock health. Infections in cattle primarily manifest through reproductive issues where infected animals shed the bacterium in birth fluids, placental tissues, and milk, serving as potential sources of transmission. Bovine herds become reservoirs, contributing to the environmental contamination of farming areas. Comprehensive studies on the prevalence, transmission routes, and associated risk factors among cattle contribute to the development of effective control strategies, ultimately safeguarding both livestock and public health.Here we determine the prevalence of Coxiella burnetii antibodies against in dairy cattle farms from Kabylia (northern Algeria) and identify the associated risk factors. Bulk tank milk samples from 184 farms were analyzed by indirect ELISA technique, 49 of them were tested positive which corresponds to a prevalence rate of 26.63% (95% CI 20.25-33.01%). Multivariate analysis by logistic regression showed that the risk factors associated with detection of anti-Coxiella burnetii antibodies are: cohabitation of cattle with small ruminants(OR = 3.74 95% CI [1.41-8.92]), exposure to prevailing winds (OR = 5.12 95% CI [2.11-13.45]), and the veterinarian visits frequency(OR = 5.67 95% CI [2.55-13.60]). These findings underscore the susceptibility of dairy cattle to Q fever in the Kabylia region, highlighting practices that pose risks. We recommend the implementation of hygienic measures and adherence to proper farming conditions to mitigate the transmission of Q fever and reduce the associated zoonotic risk.

Serological evidence of Rift Valley fever viral infection among camels imported into Southern Algeria.

Rift Valley fever (RVF) is a mosquito-borne viral zoonosis caused by the Rift Valley fever virus (RVFV). The present work aims to investigate the epidemiological status and identify the risk factors associated with RVFV infection in dromedary camels (Camelus dromedarius) from southern Algeria. A total of 269 sera of apparently healthy camels was collected and tested using a competitive Enzyme-Linked Immunosorbent Assay (ELISA). Overall, 72 camels (26.7 %, 95 % CI: 21.4-32) were seropositive to RVFV. IgG antibodies were found to be most prevalent in camels from south-western areas, particularly in Tindouf wilaya (52.38 %, p < 0.0001), and in camels introduced from bordering Sahelian countries (35.8 %) (OR = 8.75, 95 %CI: 2.14-35.81). No anti-RVFV antibodies were detected in sera collected from local camels (0 %). Adult (5-10 years) and aged (>10 years) camels have a significantly higher risk of being infected by RVFV (OR = 2.15; 95 %CI = 1.21-3.81, OR = 2.05; 95 %CI = 1.03-4.11, respectively). This report indicated that dromedaries imported to the south-western areas are exposed to RVFV and may contribute to its spread in Algerian territories.

Seroprevalence and risk factors of Toxoplasma gondii infection in sheep in Algeria.

Toxoplasma gondii infection is recognized as one of the major causes of reproductive failure in sheep and goats. This survey was carried out in order to study the seroprevalence of Toxoplasma infection in sheep in Blida, Bouira and Medea regions from Algeria. The sample size was set at 220 animals distributed over 22 farms. Sera were assayed for T. gondii antibody detection by Modified Agglutination Test (MAT). The overall seroprevalence was 35.9% (79/220) with a herd seroprevalence of 77.3% (17/22). The prevalence was significantly higher in Medea (45.7% of 116 sheep), compared to Blida (27.7% of 83 sheep). Bouira region showed the lowest prevalence with 3 positive samples (14.3%) over 21 sheep. Logistic regression analysis revealed that the likelihood of T. gondii infection was higher in semi-extensive sheep breeding, in regions where the presence of cats is strong, and in highlands when compared with semi-intensive sheep breeding, weak presence of cat and in lowland, respectively. This study shows a high seroprevalence of Toxoplasma infection in sheep in these areas.

First Molecular Detection of Pathogens Leptospira in Common Rodent Captured in North Algeria Urban Areas.

Leptospirosis is an anthropozoonosis disease of worldwide distribution caused by mobile spirochetes of the genus Leptospira and rodents, mainly rats, are described as its primary reservoir. In Algeria, there is limited data about the prevalence of Leptospira spp. in humans and animals, as well as Leptospira carriage in wild rodents. The study aimed to highlight the importance of rodents as a reservoir of Leptospira bacterium in Blida city in Algeria by detecting and identifying circulating Leptospira species in the rodent population. A total of 101 rodents, 95 Rattus Norvegicus, 5 Rattus Rattus, and 1 Mus Musculus were captured and tested for pathogenic Leptospira spp. byreal-time PCR targeting the Leptospira 16S rRNA (rrs) gene, revealing a total prevalence of 40.6%, 95% IC [30.9-50.8%]. Positive samples were subjected to species-specific real-time PCR assays targeting L. interrogans, L. noguchii, L. borgpetersenii, and L. kirschneri for species identification. However, positive samples for which Leptospira-species could not be determined were subjected to conventional PCR targeting the partial 16S rRNA (rrs) gene, and amplified DNA was subjected to sequencing. Leptospira spp. was detected in 36 kidney, 16 urine, and three lung specimens. L. interrogans was identified in 39 rodents and L. borpetersenii in one rodent; however, one rodent with renal carriage could not be typed due to poor DNA quality. This study provides the first description of pathogenic Leptospira spp. in wild rodents in Algeria. These findings suggest a high potential risk of leptospirosis transmission from rodents to humans and animals in Algeria and therefore imply the adoption of prophylactic measures. In addition, further studies, including different animals and rodent species, should be conducted to clarify the epidemiology of this disease in Algeria.

Pathological Findings in Cattle Slaughtered in Northeastern Algeria and Associated Risk Factors.

Meat is a food of animal origin, which can be contaminated by infectious, parasitic and other non-infectious agents responsible for diseases, which threaten the health of consumers. This still poses a public health problem in Algeria and in many countries. In order to assess the epidemiological situation of certain diseases in the Taher region in Jijel and to determine the influence of certain variation factors and to estimate the risk on public health, a study was extended over a period of 14 months on a total of 1756 cattle slaughtered at the Taher slaughterhouse. The results showed that 609 cattle (34.68%) showed lesions. The highest rate of pathological findings was observed on the liver (37.27%) followed by the lungs (30.21%). The lowest rate was recorded on the digestive system (0.33%) followed by the kidneys (1.14%). In addition, the liver and lungs were more contaminated with hydatid cyst compared to other organs (20.69%, 19.05%, respectively). Our data showed that the diseases affected more females (55.82%) than males (44.17%) (p < 0.001). Furthermore, cattle aged between 3 and 5 years were the most affected (43.51%) and local breed cattle showed more lesions (71.59%). These results testify to the real risk represented by the consumption of organs affected by diseases, and the need to recognize the agents of contamination and the mode of transmission and to implement an extension and control program in this region depending on the epidemiological aspect of the lesions.

Indicators and risk factors of infectious laryngotracheitis in layer hen flocks in Algeria.

BACKGROUND AND AIM: Since 2017, there have been epidemics with respiratory disorders in the laying hen farms in Algeria, as signs and lesions, respiratory difficulties, and hemorrhagic tracheitis, which closely like laryngotracheitis. This study aimed to analyze the epidemiological, serological, and clinical indicators, as well as the risk factors, of infectious laryngotracheitis (ILT) in layer hen flocks in Algeria. MATERIALS AND METHODS: A total of 1728 layer hens were sampled randomly from 48 poultry houses. Blood samples were collected from each hen at the wing vein area, and an indirect enzyme-linked immunosorbent assay was done using an IDvet® kit. RESULTS: The flocks showed 56.25% seroprevalence. Clinical signs and gross lesions of ILT suspect cases included respiratory signs characterized by hemorrhagic tracheitis and sinusitis; conjunctivitis; egg drop; and a low mortality rate varying from 5% to 20%. Statistical analyses showed the effect of risk factors on the seropositivity for ILT in 48 layer flocks. When the vaccination was not applied, flocks were significantly more seropositive by 54% (odds ratio OR=1.54, p=0.01) compared to vaccinated flocks. Furthermore, flocks with poor hygiene were more seropositive by 68% (OR=1.68, p=0.002) compared to those with good hygiene. Finally, flocks with decreased egg production between 10% and 30% were significantly more seropositive by 42% (OR=1.42, p=0.04) than those with egg production >30%. CONCLUSION: The serological survey revealed anti-ILT virus antibodies, signifying the circulation of this virus in layer hen farms in Algeria. Correct vaccination protocol, strict biosecurity measures, rapid diagnosis, and detection of latent carriers are necessary to control and eradicate the disease from layer farms.

Molecular detection of the B1 gene of Toxoplasma gondii in blood samples of female sheep and goats in Tebessa, northeastern Algeria.

Toxoplasmosis, caused by Toxoplasma gondii, is a parasitic zoonosis of crucial medical and veterinary importance. It is mainly diagnosed by serological methods which are limited by insufficient sensitivity. Therefore, it is necessary to rely on direct detection of the parasite. The present study was aimed for direct detection of the parasite DNA in the blood samples of sheep and goats using PCR targeting the B1 gene. The study was carried out in 20 small ruminant farms between 2016 and 2018 in Tebessa region, part of north-eastern Algeria, and concerned 227 and 91 aborted female sheep and goats respectively. DNA of T. gondii was detected in 35.24 % and 18.68 % blood samples of sheep and goats respectively (p < 0.001). Molecular prevalence was higher in 13-24 month old female sheep (93.33 %) than 1-12 month old female sheep (14.37 %) (p < 0.0001). While, in goats no significant difference was observed in relation to age. Female sheep that aborted between 1-60 days of gestation were found to be more infected (46.41 %) compared to females that aborted between 61-120 days of gestation (12.16 %) (p < 0.001). Whereas, female goats that aborted between 61-120 days of gestation were found to be more infested (30.77 %) compared to females that aborted between 1-60 days of gestation (16.67 %) (p < 0.001). This study revealed that small ruminants are highly infected with T. gondii, which represents a major risk for the consumer in Tebessa. Further studies are needed to improve our knowledge of the different genotypes of T. gondii infecting small ruminant population.

Molecular detection of avian spirochete Borrelia anserina in Argas persicus ticks in Algeria.

Argasid ticks are one of the most important poultry ectoparasites. They affect poultry directly through blood meal and indirectly through the transmission of pathogens essentially Borrelia anserina, agent of avian borreliosis, one of the most widespread poultry diseases in the world, and is of great economic importance. This study was conducted between April 2014 and March 2015 in the region of Ksar El Boukhari, Algeria, in order to investigate the presence of soft ticks in laying hen farms and to detect B. anserina bacteria using molecular tools. DNA was extracted and screened for the presence of Borrelia spp. DNA by real-time polymerase chain reaction (qPCR). Borrelia spp. screening was performed using primers and probe targeting the 16S rRNA gene. A total of 83 traditional laying hen farms were visited, of which 39 (46.98 %) were found infested with A. persicus tick. Molecular analysis revealed that 2/34 (5.88 %) of ticks were infected by B. anserina. None of the ticks tested were positive for Rickettsia spp., and Coxiella burnetii. These results constitute the first report in Algeria of A. persicus harboring B. anserina.

Serological, clinical, and risk factors of the Newcastle disease on broilers flocks in Algeria.

AIM: The work aimed at studying the serological and clinical factors, as well as the risk factors of the Newcastle disease (ND) on broilers herds in Algeria. MATERIALS AND METHODS: A sample of 1248 birds was randomly selected from 52 broiler flocks. We took blood samples from each bird at the level of the wing vein area where an indirect enzyme-linked immunosorbent assay technique was carried out through the use of an IDvet kit. RESULTS: The flocks showed 82.69% of seroprevalence. Clinically speaking, the most common symptoms were sneezing, rale, greenish diarrhea, torticollis, and motor discords. Most commonly observed postmortem lesions were the proventriculitis, tracheitis, and enteritis. Especially, the caeca are hemorrhagic. The scores show the effect of risk factors. There was a significant effect on the mortality, the hygiene and vaccination groups on antibody titers in time 2. The antibody titers were elevated in the herd that recorded a high mortality (more than 10%) compared with those which recorded a low mortality (<10%) (p=0.002). Therefore, the antibody titers were elevated in herds with bad hygiene, compared with the ones with good hygiene (p=0.04). At last, when broiler chicken were not boosted by ND vaccine, flocks appeared to be more seropositive (p=0.02). CONCLUSION: The serological survey conducted in this study provided an important scope for ND as a dominant viral disease in broilers. Many factors are responsible for the onset of these diseases; correct biosecurity measures are needed to reduce the impact of this pathology in poultry farms.

Antibiotic susceptibility of Staphylococci isolated from bovine mastitis in Algeria.

OBJECTIVE: This work aimed to determine the resistance and/or the susceptibility to antibiotics of staphylococci isolated from cattle with mastitis in the North of Algeria. MATERIALS AND METHODS: The disk diffusion method was carried out to reveal the antibiotic resistance in accordance to the National Committee for Clinical Laboratory Standards guidelines in the Mueller-Hinton agar. RESULTS: Coagulase-negative Staphylococci (CNS) isolates showed more resistance to Cefoxitin, Amoxicillin + Clavulanic Acid, Vancomycin, Trimethoprime Sulfamethoxazole, Clindamycine, Neomycin, and Erythromycin than Coagulase-positive Staphylococci (CPS). CPS were more resistant to Penicillin and Tetracycline as compared to CNS strains; however, all these strains presented sensitivity to Gentamicin and neomycin. CONCLUSION: The Staphylococci showed high resistance to the beta-lactam antibiotics. As far as the authors know, these molecules are used with or without control in different protocols to prevent and cure the mastitis in Algeria.

Serological and histopathological investigation of brucellosis in cattle in Medea region, Northern Algeria.

AIM: This study was performed to determine the prevalence of bovine brucellosis in Medea region, Northern Algeria. MATERIALS AND METHODS: The study was carried out on 495 non-vaccinated cattle, of which 280 (30 males and 250 females) belonged to 57 cattle farms and 215 cows were sampled at abattoirs of Medea. Sera collected from the cattle were tested using the Rose Bengal test and confirmed by histopathological analysis. RESULTS: Serological examination revealed that 7/57 farms (12.28%) were infected, of which 7/280 (2.5%) cattle were seropositive. The prevalence in females and males was 2.4% (6/250) and 3.33% (1/30), respectively. No significant difference has been observed between females and males. Older animals (≥8 years) were infected more. The prevalence of infection was 9.1%. Seroprevalence of Brucella infection in cows that have already had abortion was higher compared with non-aborted cows (4.34% and 2.20%, respectively). In abattoirs, a total of 25 (11.62%) seropositive cows were detected, and the histopathological analysis was positive in all these cows. CONCLUSION: The study indicates that brucellosis indeed exists in cattle in Medea and shows that the meat of slaughtered cattle tested positive for brucellosis may constitute a real risk of transmission to both butchery personnel and consumers, which requires that the meat of infected animals should be analyzed before being marketed.

Presence of Rickettsia aeschlimannii, 'Candidatus Rickettsia barbariae' and Coxiella burnetii in ticks from livestock in Northwestern Algeria.

Livestock and their ectoparasites are involved in the epidemiology of several zoonotic diseases. Studies regarding the molecular detection of infectious agents in ticks from Northwestern Algeria are scarce. Thus, the presence of spotted fever group Rickettsia spp., Anaplasmataceae microorganisms and Coxiella burnetii was investigated in ticks collected from ruminants in Sidi Bel Abbes and Saida provinces. Rickettsia aeschlimannii was detected in one Hyalomma excavatum pool and one H. marginatum pool. Moreover, 'Candidatus Rickettsia barbariae' was found in one H. excavatum and six Rhipicephalus bursa pools. Lastly, Coxiella burnetii was amplified in two H. excavatum and two R. bursa pools. No Anaplasmataceae bacterium was detected. This study demonstrates the presence of the tick-associated microorganism 'Candidatus R. barbariae' in the North of Africa, and corroborates the presence of the zoonotic pathogens R. aeschlimannii and C. burnetii in Algeria.

Zoonotic Cryptosporidium species and subtypes in lambs and goat kids in Algeria.

BACKGROUND: Little is known on the occurrence and identity of Cryptosporidium species in sheep and goats in Algeria. This study aimed at investigating the occurrence of Cryptosporidium species in lambs and goat kids younger than 4 weeks. METHODS: A total of 154 fecal samples (62 from lambs and 92 from kid goats) were collected from 13 sheep flocks in Médea, Algeria and 18 goat flocks across Algiers and Boumerdes. They were screened for Cryptosporidium spp. by nested-PCR analysis of a fragment of the small subunit (SSU) rRNA gene, followed by restriction fragment length polymorphism and sequence analyses to determine the Cryptosporidium species present. Cryptosporidium parvum and C. ubiquitum were further subtyped by sequence analysis of the 60 kDa glycoprotein gene. RESULTS: Cryptosporidium spp. were detected in 17 fecal samples (11.0%): 9 from lambs (14.5%) and 8 from goat kids (8.7%). The species identified included C. parvum in 3 lambs, C. xiaoi in 6 lambs and 6 goat kids, and C. ubiquitum in 2 goat kids. Cryptosporidium infections were detected mostly in animals during the first two weeks of life (7/8 for goat kids and 7/9 for lambs) and in association with diarrhea occurrence (7/17 or 41.2% goat kids and 7/10 or 70.0% lambs with diarrhea were positive for Cryptosporidium spp.). Subtyping of C. parvum and C. ubiquitum isolates identified the zoonotic IIaA13G2R1 and XIIa subtype families, respectively. Minor differences in the SSU rRNA gene sequences were observed between C. xiaoi from sheep and goats. CONCLUSIONS: Results of this study indicate that three Cryptosporidium species occur in lambs and goat kids in Algeria, including zoonotic C. parvum and C. ubiquitum. They are associated with the occurrence of neonatal diarrhea.

Infectious bursal disease virus in Algeria: Detection of highly pathogenic reassortant viruses.

Infectious bursal disease (IBD) is an immunosuppressive viral disease, present worldwide, which causes mortality and immunosuppression in young chickens. The causative agent, the Avibirnavirus IBDV, is a non-enveloped virus whose genome consists of two segments (A and B) of double-stranded RNA. Different pathotypes of IBDV exist, ranging from attenuated vaccine strains to very virulent viruses (vvIBDV). In Algeria, despite the prophylactic measures implemented, cases of IBD are still often diagnosed clinically and the current molecular epidemiology of IBDV remains unknown. The presence of the virus and especially of strains genetically close to vvIBDV was confirmed in 2000 by an unpublished OIE report. In this study, nineteen IBDV isolates were collected in Algeria between September 2014 and September 2015 during clinical outbreaks. These isolates were analyzed at the genetic, antigenic and pathogenic levels. Our results reveal a broad genetic and phenotypic diversity of pathogenic IBDV strains in Algeria, with, i) the circulation of viruses with both genome segments related to European vvIBDV, which proved as pathogenic for specific pathogen-free chickens as vvIBDV reference strain, ii) the circulation of viruses closely related - yet with a specific segment B - to European vvIBDV, their pathogenicity being lower than reference vvIBDV, iii) the detection of reassortant viruses whose segment A was related to vvIBDV whereas their segment B did not appear closely related to any reference sequence. Interestingly, the pathogenicity of these potentially reassortant strains was comparable to that of reference vvIBDV. All strains characterized in this study exhibited an antigenicity similar to the cognate reference IBDV strains. These data reveal the continuous genetic evolution of IBDV strains in Algerian poultry through reassortment and acquisition of genetic material of unidentified origin. Continuous surveillance of the situation as well as good vaccination practice associated with appropriate biosecurity measures are necessary for disease control.

Divergent Cryptosporidium parvum subtype and Enterocytozoon bieneusi genotypes in dromedary camels in Algeria.

Little information is available on the occurrence of the zoonotic protists Cryptosporidium spp. and none on Enterocytozoon bieneusi in camels. This preliminary study was conducted to examine the identity of Cryptosporidium subtypes and E. bieneusi genotypes in dromedary camels in Algeria. A total of 39 fecal specimens were collected from young camels. PCR-sequence analysis of the small subunit rRNA was used to detect and genotype Cryptosporidium spp. Cryptosporidium parvum present was further subtyped by sequence analysis of the 60 kDa glycoprotein gene. PCR-sequence analysis of the ribosomal internal transcribed spacer gene was used to detect and genotype E. bieneusi. Altogether, two and eight of the specimens analyzed were positive for C. parvum and E. bieneusi, respectively. The former was identified as a new subtype that is genetically related to the C. hominis If subtype family, whereas the latter was identified as two related genotypes (Macaque1 and a novel genotype) in the newly assigned E. bieneusi genotype group 8. Although they are not known hosts for C. parvum and E. bieneusi, camels are apparently infected with genetically distinct variants of these pathogens.

Cryptosporidium-associated diarrhoea in neonatal calves in Algeria.

Neonatal calf diarrhoea triggered by the enteric protozoan parasite Cryptosporidium is a leading cause of morbidity and mortality in calves aged 1-month-old or younger globally. Infected cattle in general and calves in particular have also been demonstrated as major contributors of zoonotic C. parvum oocysts in the environment and have been linked to a number of waterborne outbreaks of human cryptosporidiosis. Little is known on the occurrence, geographical distribution, and molecular diversity of Cryptosporidium infections affecting bovine populations in Algeria. In this study faecal specimens were randomly collected from 460 cattle aged between two days and 18 months on 10 farms located in the provinces of Aïn Defla, Blida, Sétif, and Tizi Ouzou between the autumn of 2015 and the spring of 2016. Faecal samples were microscopically examined using the modified Ziehl-Neelsen acid-fast technique as screening method. Microscopy-positive samples were confirmed by a commercial coproantigen enzyme-linked immunosorbent assay (Bio-X Diagnostics). The identification of Cryptosporidium species and sub-genotypes in confirmed samples was conducted by PCR and sequence analyses of the small subunit ribosomal RNA (ssu rRNA) and the 60 kDa glycoprotein (gp60) genes of the parasite. Overall, 52.2% (240/460) of the investigated cattle tested positive to Cryptosporidium by microscopy. The infection was widespread in all 10 farms surveyed, but was significantly more prevalent in those from Blida in the central part of the country. Bovine cryptosporidiosis affected cattle of all age groups but with different outcomes. Pre-weaned (up to one month old) calves typically presented with diarrhoea, whereas older animals mostly harboured sub-clinical infections. The commercial ELISA used only detected 15.8% (38/240) of the samples that previously tested positive by microscopy, demonstrating a poor performance in field epidemiological surveys. Sequence analysis of the 29 isolates generated at the ssu rRNA loci confirmed the presence of four Cryptosporidium species including C. parvum (72.4%), C. bovis (13.8%), C. andersoni, (3.4%), and C. ryanae (3.4%). Two additional isolates (7.0%) could only be identified at the genus level. Eight out of the 21 isolates assigned to C. parvum were identified as sub-genotype IIaA16G2R1 at the gp60 locus. C. parvum was almost exclusively found infecting pre-weaned calves, whereas C. ryanae and C. andersoni were only detected in asymptomatic animals. Bovine cryptosporidiosis is highly endemic in the surveyed area and represents a veterinary public health concern that should be adequately tackled by Algerian veterinary health authorities and policy makers.

The characterization of Brucella strains isolated from cattle in Algeria reveals the existence of a B. abortus lineage distinct from European and Sub-Saharan Africa strains.

Brucellosis is a zoonosis caused by bacteria of the genus Brucella that causes important economic losses and human suffering worldwide. Brucellosis control requires an understanding of the Brucella species circulating in livestock and humans and, although prevalent in African countries of the Mediterranean basin, data for this area are mostly restricted to isolates obtained from humans and small ruminants. Here, we report the characterization of twenty-four Brucella strains isolated from Algerian cattle. Bruce-ladder multiplex PCR and conventional biotyping showed that Algerian cattle are infected mostly by B. abortus biovar 3, and to less extent by B. abortus biovar 1 and B. melitensis biovar 3. Extended AMOS-ERY PCR showed that all Algerian B. abortus biovar 3 strains were of the subgroup 3b. Although by multi locus variable number of tandem repeats analysis (MLVA) most isolates were closer to the European counterparts, five strains displayed characteristics distinct from the European isolates and those of countries across the Sahara, including three repetitions of marker Bruce55. These five strains, plus an earlier isolate from an Algerian human patient, may represent a lineage close to clades previously described in Africa. These data provide the basis for additional molecular epidemiology studies in northern Africa and indicate that further bacteriological and molecular investigations are necessary for a complete understanding of the epidemiology of cattle brucellosis in countries north and south of the Sahara.

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

Query (Q) fever is a globally distributed zoonotic disease caused by Coxiella burnetii, a bacterial agent for which ruminants are the most prevalent natural reservoir. Data regarding Q fever infection in camels in Algeria are limited. Therefore, a survey to detect seroprevalence of C. burnetii antibodies was conducted among healthy camel populations in a vast area in southeastern Algeria to determine distribution of the Q fever causative organism and to identify risk factors associated with infection. Between January and March 2016, blood samples were collected from 184 camels and serum samples were subsequently analysed using a commercial Enzyme-Linked Immunosorbent Assay (ELISA) kit. At the time of blood collection, a questionnaire investigating 13 potential predisposing factors associated with C. burnetii seropositivity was completed for every dromedary camel and herd. Results were analysed by a chi-square (χ2) test and multivariate logistic regression. The seroprevalence of C. burnetii at the animal level was 71.2% (95% CI: 65.2-78.3) and 85.3% (95% CI: 72.8-97.8) at the herd level. At the animal level, differences in seroprevalence were observed because of herd size, animal age, animal sex, presence of ticks and contact with other herds. A multivariable logistic regression model identified three main risk factors associated with individual seropositivity: (1) age class > 11 years (OR = 8.81, 95% CI: 2.55-30.41), (2) herd size > 50 head (OR = 4.46, 95% CI: 1.01-19.59) and (3) infestation with ticks (OR 2.2; 95% CI: 1.1-4.5). This study of seroprevalence of C. burnetii infection in camels in Algeria revealed a high seroprevalence of Q fever in camel populations in southeastern Algeria and provided strong evidence that Q fever represents an economic, public health and veterinary concern. Appropriate measures should be taken to prevent the spread of C. burnetii and to reduce the risk of Q fever in farm animals and humans in this agro-ecologically and strategically important region of North Africa.