Ruminant Herds Research Articles

New Generation Vaccine Strategies against COVID-19

Immunisation Schedule. Influenza A (H5N1) update: "Bird flu spillover to mammals needs to be monitored closely, risk to humans currently low but we must prepare". (WHO). Respiratory Syncytial Virus (RSV) Bivalent Subgroups A and B Vaccine for Infants and Adults (due 2023). False Listing of RB51 as Approved Medicine for Brucellosis or Malta Fever. Streptococcus pneumoniae PCV20. R21/Matrix-M™ Malaria (Plasmodium falciparum) vaccine 77% efficacy (due 2023). Bivalent SARS-Cov-2. [I am very thankful to receive links, additions and corrections to update, and to remove any obsolete material herein if spotted. Anti-Covid-19, anti-MMR, anti-Gardasil, anti-poliovirus anti-vaxxer depopulating messages are both unwelcome and repulsive to me.] BREAKING NEWS: Vaccine Catastrophe - Veterinary Vaccine (Live-Attenuated Brucella abortus strain RB51) has incorrectly been indicated as an 'approved' prophylactic therapy for human vaccination against Brucellosis or Malta Fever (also variously known as ‘Mediterranean Fever’ and ‘Undulant Fever’). This error is totally inexcusable as this strain is extremely harmful when given to humans. Immunisation Schedule for Zaire Ebola virus for work where large bull (bovine) and buffalo herds are present (put together for the rescue and care insurers). Zaire Ebola contamination management in large herds of aforesaid large ruminants proves problematic with the biohazard suit that protect from the disease vectors as the animals respond aggressively to the human protective gear leading to panicking animals attacks, attempts of human butchery and animal rummage where people and properties can suddenly become threatened, as a health protection gives rise to animal threat by the rummaging animals trampling and horn attacking people in biohazard gear. The ring fencing experimental Zaire Ebola vaccines were not available at the time of this original plan instigated where the China-based organisation prepared an emergency quantitative easing (QE) cash programme, ‘helicopter drops of money’ as a mitigation strategy to persuade the food producers and food vendors to continue serving the general public against an infection risk during a major ebola epidemic - to prevent food industry's distribution and production collapses as the personnel might otherwise decide to stop working and to stay home so as to avoid infecting themselves by the dangerous pathogen (in this case a Zaire Ebola Virus). The above can lead to severe food shortages and ultimately potential starvation occurrence unless that epidemic had not subsided soon enough to prevent this secondary consequence from emerging. Because of similarity of early Zaire Ebola symptoms to other infectious illnesses at the early stages, the work undertaken in remote areas, the lead time in medical evacuations in case of illnesses, and the immense cost of privately-funded flying hospital dispatch to carry out a rescue operation, an exhaustive mutual exclusion prophylactic scheme was initiated to minimise unnecessary calls for such a flying hospital facility (remote medical service) from overseas. Reported BEXSERO to GlaxoSmithKline on an unlisted side effect of stealthy temperature rise (see 19/03/2020 version, page 7) to +42.3C / +108.1F with weakening of normal body temperature control like sweating and relative lack of sense of highly elevated body temperature able to cause heat stroke and other related damage to body. The immunisation schedule incorporates emergency authorisation Covid-19 immunisations and coronavirus vaccines that shortly complete their approval. Some of the Covid-19 immunisations likely vanish from marketplace as soon as the pandemic is over whereas some other vaccine designs may seek themselves second life as generic coronavirus immunisations. (The research field of coronaviruses is rapidly changing with these overlooked viruses also causing many common colds is brought into spotlight.) Almost all Covid-19 products have not been tested for concomitant use with many other immunisation products and therefore a reasonable space should be allowed between immunisations to avoid adverse effect risks. Because of this one ought to consider whether at current pandemic situation some immunisation products of lesser importance should be taken and whether it is better to defer them until situation clears (considering the ongoing infections with Covid-19 variants and especially in some remote regions where sequencing of the variants is very sparse as the protection to Covid-19 is very important). Because of above reason, this schedule is not currently geared for rapid deployment in tropics as too many uncertainties lie within which good protection against Covid-19 must prevail. Section on Covid-19 products is continually expiring due to evolving situation. Updates on Streptococcus pneumoniae PCV20. The latest version of the document supersedes all earlier versions that ought to be discarded and not used.

Serological evidence of Rift Valley fever virus infection among domestic ruminant herds in Uganda

BackgroundPrior to the first recorded outbreak of Rift Valley fever (RVF) in Uganda, in March 2016, earlier studies done until the 1970’s indicated the presence of the RVF virus (RVFV) in the country, without any recorded outbreaks in either man or animals. While severe outbreaks of RVF occurred in the neighboring countries, none were reported in Uganda despite forecasts that placed some parts of Uganda at similar risk.The Ministry of Agriculture, Animal Industry and Fisheries (MAAIF) undertook studies to determine the RVF sero-prevalence in risk prone areas.Three datasets from cattle sheep and goats were obtained; one from retrospective samples collected in 2010–2011 from the northern region; the second from the western region in 2013 while the third was from a cross-sectional survey done in 2016 in the south-western region. Laboratory analysis involved the use of the Enzyme Linked Immunosorbent Assays (ELISA). Data were subjected to descriptive statistical analyses, including non-parametric chi-square tests for comparisons between districts and species in the regions.ResultsDuring the Yellow Fever outbreak investigation of 2010–2011 in the northern region, a total sero-prevalence of 6.7% was obtained for anti RVFV reacting antibodies (IgG and IgM) among the domestic ruminant population. The 2013 sero-survey in the western region showed a prevalence of 18.6% in cattle and 2.3% in small ruminants. The 2016 sero-survey in the districts of Kabale, Kanungu, Kasese, Kisoro and Rubirizi, in the south-western region, had the respective district RVF sero-prevalence of 16.0, 2.1, 0.8, 15.1and 2.7% among the domestic ruminants combined for this region; bovines exhibited the highest cumulative sero-prevalence of 15.2%, compared to 5.3 and 4.0% respectively for sheep and goats per species for the region.ConclusionsThe absence of apparent outbreaks in Uganda, despite neighboring enzootic areas, having minimal restrictions to the exchange of livestock and their products across borders, suggest an unexpected RVF activity in the study areas that needs to be unraveled. Therefore, more in-depth studies are planned to mitigate the risk of an overt RVF outbreak in humans and animals as has occurred in neighboring countries.

Seroprevalence and Associated Risk Factors of Bovine Brucellosis at the Wildlife-Livestock-Human Interface in Rwanda.

Bovine brucellosis is endemic in Rwanda; however, little information is available on seroprevalence and risk factors. Therefore, a cross-sectional study was conducted among cattle farmed at the wildlife-livestock-human interface (n = 1691) in five districts and one peri-urban district (n = 216). Cattle were screened using the Rose Bengal test, then the results were confirmed by indirect enzyme-linked immunesorbent assay. Potential risk factors were determined with a questionnaire and analyzed for their association with seropositivity. In all districts, the animal and herd-level seroprevalence was 7.4% (141/1907) and 28.9% (61/212), respectively, 8.3% (141/1691) and 30.9% (61/198) at the interface, and 0.0% (0/216) in peri-urban areas. Among the potential risk factors, old age (≥5 years), cattle farmed close to wildlife, herds of cattle and small ruminants, history of abortions, and replacement animals were significantly associated with brucellosis (p < 0.05). Low awareness of zoonotic brucellosis, assisting calving without biosafety protection, drinking raw milk, and manual milking were each observed in more than 21.7% of cattle keepers whose herds were seropositive. This study confirmed brucellosis endemicity in cattle farmed close to wildlife in Rwanda, suggesting the need to focus control efforts in these areas. Educated farmers with a high awareness of zoonotic brucellosis had low bovine brucellosis seropositivity, which emphasizes the importance of education.

Synthesis, bioevaluation and docking studies of some 2-phenyl-1H-benzimidazole derivatives as anthelminthic agents against the nematode Teladorsagia circumcincta

Gastrointestinal nematode infections are the main diseases in herds of small ruminants. Resistance to the main established drugs has become a worldwide problem. The purpose of this study is to obtain and evaluate the invitro ovicidal and larvicidal activity of some 2-phenylbenzimidazole derivatives on susceptible and resistant strains of Teladorsagia circumcincta. Compounds were prepared by known procedures from substituted o-phenylenediamines and arylaldehydes or intermediate sodium 1-hydroxyphenylmethanesulfonate derivatives. Egg Hatch Test (EHT), Larval Mortality Test (LMT) and Larval Migration Inhibition Test (LMIT) were used in the initial screening of compounds at 50μM concentration, and EC50 values were determined for the most potent compounds. Cytotoxicity evaluation of compounds was conducted on human Caco-2 and HepG2 cell lines to calculate their Selectivity Indexes (SI). At 50μM concentration, nine out of twenty-four compounds displayed more than 98% ovicidal activity on a susceptible strain, and four of them showed more than 86% on one resistant strain. The most potent ovicidal benzimidazole (BZ) 3 showed EC50=6.30μM, for the susceptible strain, while BZ 2 showed the lowest EC50 value of 14.5μM for the resistant strain. Docking studies of most potent compounds in a modelled Teladorsagia tubulin indicated an inverted orientation for BZ 1 in the colchicine binding site, probably due to its fair interaction with glutamic acid at codon 198, which could justify its inactivity against the resistant strain of T.circumcincta.

Re-emergence of bluetongue virus serotype 4 in Iberian ibex (Capra pyrenaica) and sympatric livestock in Spain, 2018-2019.

Between early October and mid-December 2018, mortalities were detected in Iberian ibex (Capra pyrenaica) populations in southern Spain. In the same region and period, bluetongue virus (BTV) circulation was also reported in sentinel and clinically affected domestic ruminant herds. Molecular analyses confirmed BTV serotype 4 (BTV-4) infection in eight Iberian ibexes from six hunting areas, and in 46 domestic ruminants from seven herds in close proximity to affected hunting estates. Histopathological analyses revealed vascular changes in several organs, pneumonia, lymphoid depletion, inflammatory mononuclear cell infiltrate and fibrosis as the most frequently observed lesions in the affected Iberian ibexes. Epidemiological and laboratory results indicate that BTV-4 was the main aetiological agent involved in outbreaks detected in Iberian ibex populations during the study period. Sequence analyses indicated that the BTV-4 strain detected in Iberian ibex had high homology (99.4%-100%) with strains isolated in livestock during the same period, and with previous isolates (≥98.9%) from Spain and Mediterranean Basin countries. Further studies are warranted to determine the impact of BTV-4 on the health status of Iberian ibex populations after the outbreaks. The inclusion of this species in the surveillance programme may be useful for early detection of BTV, especially in epidemiological scenarios at the wildlife-livestock interface.

Utility assessment of an Enzyme-linked immunosorbent assay for detection of subclinical cases of caseous lymphadenitis in small ruminant flocks.

The actual prevalence of CLA (caseous lymphadenitis) in small ruminant flocks is underestimated in many countries, and because it is not a notifiable disease, it will continue to spread without data and information about its real economic impact. The difficulty in the accurate identification of the causative agent in internal subclinical cases allows the disease to spread within and between flocks. This research intends to assess the utility of an ELISA (enzyme‐linked immunosorbent assay) test in the detection of internal subclinical cases of CLA in farms and to simultaneously add data on the seroprevalence of the disease in Portugal. Sera from 756 small ruminants, 70% sheep (528/756) and 30% goats (228/756) were screened for antibodies against Corynebacterium pseudotuberculosis using the ELISA technique based on a recombinant phospholipase D (ELITEST CLA # CK105A®). The animals showing internal lesions (n ꞊ 58) were sampled for the identification of the aetiological agent. In this investigation, the prevalence of CLA was 34% (258/756), with the ELISA test showing a low specificity (78%) and high sensitivity (100%). The proof was able to detect 57% (13/23) of subclinical cases of CLA confirmed by postmortem examination and conventional PCR (polymerase chain reaction). The results also reveal that goats have a higher propensity for the disease, and dairy farms and non‐extensive production units appear to be more susceptible to CLA. This research clarifies an actual problem and pointed out the importance of CLA in small ruminant herds in Portugal. Finally seems to demonstrate that the ELISA test is a good diagnostic tool for use in CLA eradication programmes.

Rift Valley fever in northern Senegal: Amodelling approach to analyse the processes underlying virus circulation recurrence.

Rift Valley fever (RVF) is endemic in northern Senegal, a Sahelian area characterized by a temporary pond network that drive both RVF mosquito population dynamics and nomadic herd movements. To investigate the mechanisms that explain RVF recurrent circulation, we modelled a realistic epidemiological system at the pond level integrating vector population dynamics, resident and nomadic ruminant herd population dynamics, and nomadic herd movements recorded in Younoufere area. To calibrate the model, serological surveys were performed in 2015–2016 on both resident and nomadic domestic herds in the same area. Mosquito population dynamics were obtained from a published model trained in the same region. Model comparison techniques were used to compare five different scenarios of virus introduction by nomadic herds associated or not with vertical transmission in Aedes vexans. Our serological results confirmed a long lasting RVF endemicity in resident herds (IgG seroprevalence rate of 15.3%, n = 222), and provided the first estimation of RVF IgG seroprevalence in nomadic herds in West Africa (12.4%, n = 660). Multivariate analysis of serological data suggested an amplification of the transmission cycle during the rainy season with a peak of circulation at the end of that season. The best scenario of virus introduction combined yearly introductions of RVFV from 2008 to 2015 (the study period) by nomadic herds, with a proportion of viraemic individuals predicted to be larger in animals arriving during the 2nd half of the rainy season (3.4%). This result is coherent with the IgM prevalence rate (4%) found in nomadic herds sampled during the 2nd half of the rainy season. Although the existence of a vertical transmission mechanism in Aedes cannot be ruled out, our model demonstrates that nomadic movements are sufficient to account for this endemic circulation in northern Senegal.

Experimental Coxiella burnetii infection in non-pregnant goats and the effect of breeding

Q fever is a zoonosis caused by the intracellular bacterium Coxiella burnetii. In Europe, small ruminants are the main source of human Q fever. Small ruminant herds can be infectious during several lambing seasons. However, it is not clear how infection is maintained in a herd and what role non-pregnant animals play in the transmission of C. burnetii. We therefore inoculated nulliparous goats with C. burnetii, isolated from the outbreak of Q fever in the Netherlands, to gain a better understanding of the role of non-pregnant goats. Seroconversion and excretion of C. burnetii were monitored after inoculation. To study the effect of breeding on the excretion of C. burnetii, the goats were naturally bred and monitored during gestation and after lambing. Our results indicate that C. burnetii infection prior to breeding did not result in infection of the placenta nor did it affect the gestation length or the number of kids born. However, one of the ten does did excrete C. burnetii in the colostrum post-partum and the bacterium was detected in the mammary gland and associated lymph nodes at necropsy. This result indicates that non-pregnant goats might play a role in maintaining Q fever in a goat herd as persistent carriers of infection.

Isolation of Mycoplasma auris from milk of goats with clinical mastitis

Abstract The unexpected presence of Mycoplasma auris was evidenced in mastitis samples collected from a dairy goat herd under surveillance programmes of contagious agalactia (CA), a serious disease affecting Mediterranean small ruminant herds. Thus, control programs based on permanent analysis of milk from bulk tank and clinical mastitis, as well as ear swabs, are currently conducted in affected areas. In order to analyze the presence of CA- causing species, three, 11 and 18 of these samples were respectively collected from the same goat herd. Mycoplasmas were isolated in four milk samples from clinical mastitis and two ear swabs samples and no other pathogen was detected. The presence of CA-causing mycoplasmas was discarded by PCR. However, M. auris was identified in all the positive samples after the amplification and posterior PCR product sequencing of a partial fragment of their 16S-ribosomal ARN gene. As far as we know, these are the first isolations of M. auris from milk of goats with clinical mastitis.

Effects of herd management and the use of ivermectin on dung arthropod communities in grasslands

Agroecosystems represent a large geographical footprint in most terrestrial landscapes, and management decisions within these systems affect their function in species conservation. We evaluated the effects that rangeland management systems (based on stocking density, rotation frequency, and the number of avermectin applications) have on conserving the dung arthropod community in the Northern Great Plains of North America. Comprehensive bioinventories of arthropods were collected from 16 rangelands using core samples of dung pats. Ivermectin was quantified in pats from each ranch using enzyme-linked immunosorbant assay (ELISA). Arthropods in dung were abundant (116,244 specimens) and diverse in eastern South Dakota (172 morphospecies). Rangelands managed with more regenerative practices (frequent rotation at high stocking densities and lack of ivermectin applications) had greater species richness, diversity, predator species abundance, and dung beetle abundance than more conventionally managed rangelands. Ivermectin quantity in cattle pats was negatively correlated with dung beetle abundance and diversity. This work shows that herd management (specifically high-intensity, frequent rotational grazing and eliminating prophylactic ivermectin use) that aims to mimic intensive grazing of large migrating herds of ruminants can foster dung arthropod community structure, a key trait correlated with nutrient cycling, pest suppression, and productivity of cattle-grazed rangelands.

Occurrence of Campylobacter jejuni and Campylobacter coli in Cattle and Sheep in Northern Spain and Changes in Antimicrobial Resistance in Two Studies 10-years Apart.

A cross-sectional survey was conducted in 2014–2016 in 301 ruminant herds to estimate C. jejuni and C. coli prevalence, and investigate their susceptibility to antimicrobials. Risk of shedding C. jejuni was higher in cattle than sheep (81.2% vs. 45.2%; ORadj = 5.22, p < 0.001), whereas risk of shedding C. coli was higher in sheep than in cattle (19.1% vs. 11.3%; ORadj = 1.71, p = 0.128). Susceptibility to six antimicrobials was determined by broth microdilution using European Committee for Antimicrobial Susceptibility Testing (EUCAST) epidemiological cut-off values. C. coli exhibited higher resistance (94.1%, 32/34) than C. jejuni (65.1%, 71/109), and resistance was more widespread in isolates from dairy cattle than beef cattle or sheep. Compared to results obtained 10-years earlier (2003–2005) in a similar survey, an increase in fluoroquinolone-resistance was observed in C. jejuni from beef cattle (32.0% to 61.9%; OR = 3.45, p = 0.020), and a decrease in tetracycline-resistance in C. jejuni from dairy cattle (75.0% to 43.2%; OR = 0.25, p = 0.026). Resistance to macrolides remained stable at low rates and restricted to C. coli from dairy cattle, with all macrolide-resistant C. coli showing a pattern of pan-resistance. Presence of the single nucleotide polymorphisms (SNPs) associated to quinolone and macrolide resistance was confirmed in all phenotypically resistant isolates. The increase in fluoroquinolone resistance is worrisome but susceptibility to macrolides is reassuring.

A framework for reviewing livestock disease reporting systems in high-risk areas: assessing performance and perceptions towards foot and mouth disease reporting in the Thrace region of Greece, Bulgaria and Turkey.

Disease reporting is an essential frontline component of surveillance systems, particularly for detecting incursions of new and emerging diseases. It has the advantages of being comprehensive and continuous, with the potential to reduce the time of disease detection and the extent of consequent spread. A number of exotic diseases, including sheep and goat pox, lumpy skin disease, peste des petits ruminants and foot and mouth disease have historically entered into south-eastern Europe through the Thrace region, which extends across neighbouring areas of Greece, Bulgaria and Turkey. In this high-risk area, multiple factors can reduce the sensitivity of disease reporting across the diverse production systems and animal health services need robust and effective disease reporting systems. While describing a training exercise designed to provide animal health services of the three countries with the knowledge and skills for conducting comprehensive in-country assessments, we provide an initial evaluation of the sensitivity of foot and mouth disease reporting and identify gaps and constraints in the Thrace region. An expert elicitation approach was used to consult official veterinarians from central and local animal health authorities of the three countries, and scenario trees modelling was applied to analyse the collected data. The reported sensitivity of disease reporting often varied between the central and local veterinary authorities within the three countries. Awareness of clinical disease, of reporting procedures and of biosecurity measures affected the early stages of disease reporting, particularly in the production systems identified at lower reporting sensitivity such as small ruminant's herds, mixed bovine herds and backyard herds. Despite its limitations this training exercise provided an effective framework (a) to develop capacities of the veterinary services in the region and (b) to supply initial evidence for guiding further interventions targeting those sectors and stakeholders at lower reporting sensitivity to reduce risks of disease introduction.

Longitudinal microbiological evaluation of subclinical non-aureus staphylococcal intramammary infections in a lentivirus-infected dairy goat herd

The objectives of this study were to 1) correlate pre-partum teat skin colonization with non-aureus staphylococcal (NAS) intramammary infection (IMI) in early lactation, and 2) evaluate infection dynamics of subclinical NAS IMI in goats during lactation in a small ruminant lentivirus-infected herd. Pre-partum teat skin swabs (41 goats, 82 halves) and post-partum half-level milk samples (106 goats, 203 halves) were collected at various intervals starting at ≤10 days in milk (DIM) until ≥120 DIM. Teat skin colonization and IMI were defined by culture and strain-typing. The association between the pre-kidding udder-half teat skin sample status and early lactation IMI status for a given species was investigated using McNemar’s exact test or logistic regression. Time to IMI elimination and time to new IMI were evaluated by discrete-time survival analysis. Halves with S. caprae isolated from teat skin prior to kidding had increased odds of S. caprae IMI ≤ 10 DIM. Time to IMI elimination varied as a function of NAS species. Intramammary infections detected >10 DIM had a higher hazard of elimination (hazard ratio [HR] 5.6, 95% CI 2.8–11.2) than IMI detected ≤10 DIM. The presence of an IMI in the contralateral half was associated with a higher hazard of new IMI (HR 2.1, 95% CI 1.3–3.4) in an uninfected half. Further studies on interventional strategies targeting early IMI and IMI caused by persistent species are warranted.

Occurrence of anti-Brucella abortus agglutinins in small ruminants in Sergipe

ABSTRACT: The objective this study was to evaluate the occurrence of small ruminants seropositive for Brucella abortus in Sergipe, Brazil. Samples of sheep (1,200) and goats (675) serum blood was collected from 101 farms of 25 counties of the three mesoregions of the state. The technique of Acidified Buffered Acid stained with Rose Bengal (RB) was used and all samples confirmed a positive result using the 2-Mercaptoethanol technique. Four (0.21%) seropositive animals were diagnosed by technique AAT stained with RB, three sheep’s (0.25%) and a goat (0.15%), were confirmed by the 2ME test. In all the positive properties, the intercropping of small ruminants with cattle was adopted, favoring the contact with the agent. The prevalence of anti-B. abortus antibodies in herds of small ruminants in Sergipe is described for the first time, and is low, however, it is important to identify seropositive animals to be discarded due to their zoonotic potential.

Caprine herpesvirus 1: A successful eradication program in dairy goat herd

This retrospective analysis and report describes the successful testing and eradication and the ongoing surveillance program for Caprine herpesvirus 1 (CpHV-1) in a closed herd of dairy goats. The methods of eradication and surveillance for CpHV-1 described herein may also serve as an ideal model to eradicate other diseases impacting small ruminant herds.

A cysteine protease from the latex of Ficus benjamina has in vitro anthelmintic activity against Haemonchus contortus.

Haemonchus contortus is a gastrointestinal nematode that is responsible for high mortality rates in ruminant herds. The resistance of nematodes to synthetic anthelmintics is widespread and requires a continuous search for new bioactive molecules, such as proteins. The objective of this study was to evaluate the anthelmintic potential of a protease purified from the latex of Ficus benjamina against H. contortus . Fresh latex was collected from plants via small incisions in the green stems, the rubber was removed by centrifugation, and the latex protein extract (LPE) was obtained. After LPE fractionation with ammonium sulfate and chromatography of the fraction containing the highest proteolytic activity on CM-cellulose, a cysteine protease (FbP) was purified. FbP has a molecular mass of approximately 23.97 kDa, and its proteolytic activity was stable between pH 6.0 and pH 10 and over a broad temperature range, with optimum activity at 60 °C. FbP inhibited both the development and exsheathment of H. contortus larvae, with 50% effective concentrations of 0.26 and 0.79 mg/mL, respectively. We conclude that this cysteine protease from F. benjamina latex with anthelmintic activity against H. contortus could be a promising alternative for the development of products for use in parasite control programmes.

Molecular prevalence of Chlamydia and Chlamydia-like bacteria in Tunisian domestic ruminant farms and their influencing risk factors.

Chlamydia and Chlamydia-like bacteria are well known to infect several organisms and may cause a wide range of diseases, particularly in ruminants. To gain insight into the prevalence and diversity of these intracellular bacteria, we applied a pan-Chlamydiales real-time PCR to 1,134 veterinary samples taken from 130 Tunisian ruminant herds. The true adjusted animal population-level prevalence was 12.9% in cattle, against 8.7% in sheep. In addition, the true adjusted herd-level prevalence of Chlamydiae was 80% in cattle and 25.5% in sheep. Chlamydiales from three family-level lineages were detected indicating a high biodiversity of Chlamydiales in ruminant herds. Our results showed that Parachlamydia acanthamoebae could be responsible for bovine and ovine chlamydiosis in central-eastern Tunisia. Multivariable logistic regression analysis at the animal population level indicated that strata and digestive disorders variables were the important risk factors of bovine and ovine chlamydiosis. However, origin and age variables were found to be associated with bovine and ovine chlamydiosis, respectively. At the herd level, risk factors for Chlamydia positivity were as follows: abortion and herd size for cattle against breeding system, cleaning frequency, quarantine, use of disinfectant and floor type for sheep. Paying attention to these risk factors will help improvement of control programs against this harmful zoonotic disease.

An epidemological study on Peste des petits ruminants in Tripoli Region, Lybia.

A cross‑sectional study was conducted in Libya in 7 areas of Tripoli to determine the seroprevalence of Peste des Petits Ruminants (PPR) Virus (PPRV) in small ruminants (sheep and goats) between June and August 2013, and to identify the potential risk factors associated with the infection. The study involved 10% of small ruminant herds with ≥50 animals in the Tripoli region. They were selected randomly (15 herds), and 35 to 58 samples, depending on its size, were collected from each selected herd. Seven‑hundred and twenty‑one serum samples from unvaccinated animals (601 of sheep and 120 of goats) were collected and then tested using cELISA commercial kit in the National Center of Animal Health Laboratory in Tripoli, Libya. The overall seroprevalence was 46.7% [(sheep 44.3% (266/601) and goats 59.2% (71/120)]. Mean within‑herd prevalence was 48.5% (95% CI: 32.1% ‑ 64.8%), and the herd prevalence was 93.3% (14/15). Various risk factors at the animal and herd levels were analysed by multivariable logistic regression model (forward stepwise). The results identified breed, source of animal, and region as significant risk factors (p< 0.05). As for the source of new animal to the farm, PPRV seroprevalence was highest in illegally imported animals (90.9%), followed by the seroprevalence in animal legitimately acquired (55.8%), and by the seroprevalence in animals belonging to the same herd (4.7%). The seroprevalence among breeds was 69.5% (228÷328) in illegally imported animals, whereas 27.7% (109÷393) was found to be in local breed. Seroprevalence in the areas considered in this study was higher (66.2%) in Al‑Mashroa area followed by Ein‑zara (57.8%), Arada (50%), Ben‑Own (47%), AL‑Naem (37.5), Ber‑Alalem (24.5) and in Tajora (0%). The results indicated that PPRV virus was actively circulating in Tripoli regions and that the illegal importing of animals was the main source of spreading PPR in Tripoli regions, showing that better efforts should be made to raise public awareness with respect to biosecurity.

Survey of Victorian small ruminant herds for mycoplasmas associated with contagious agalactia and molecular characterisation of Mycoplasma mycoides subspecies capri isolates from one herd.

Regarded as one of the most expensive production diseases of dairy sheep and goats, contagious agalactia (CA) is caused by any of four agents: Mycoplasma agalactiae, M. mycoides subspecies capri (Mmc), M. capricolum subspecies capricolum (Mcc) and M. putrefaciens. Although CA is worldwide in distribution, it has not been reported in Australia, even though studies between the 1950s and 1980s isolated each agent from sheep or goats without any clinical signs associated with it. The aim of this study was to examine sheep and goats in Victoria, Australia, for the presence of CA-associated mycoplasmas and to investigate the evolutionary relationships of these isolates by comparing their genetic differences with their counterparts from other parts of the world. A 3-year epidemiological survey of small ruminant populations in Victoria, Australia, was conducted for the presence of CA-associated mycoplasmas and the isolates obtained were genotyped by multilocus sequence typing (MLST). Mmc was the only CA-associated agent isolated from the 1358 samples analysed in the study, but was not associated with CA on the property where it was found. MLST analyses of Mmc strains revealed a distinct clustering of Australian isolates into a novel clade, with the closest relatives being strains from Europe. The distinct clustering is consistent with the absence of clinical disease in Australia. The isolation of Mmc indicates that this subspecies persists in Australian small ruminant populations. However, full genome sequencing and in vitro animal experimentation are needed to unequivocally demonstrate the avirulence of Australian strains.

A longitudinal study of serological responses to Coxiella burnetii and shedding at kidding among intensively-managed goats supports early use of vaccines

Vaccination against Coxiella burnetii, the cause of Q fever, is reportedly the only feasible strategy of eradicating infection in ruminant herds. Preventive vaccination of seronegative goats is more effective in reducing shedding of C. burnetii than vaccinating seropositive goats. The age at which goats born on heavily-contaminated farms first seroconvert to C. burnetii has not yet been documented. In a 16-month birth cohort study, the age at which goats seroconverted against C. burnetii was investigated; 95 goats were bled every 2 weeks and tested for antibodies against C. burnetii. Risk factors for seroconversion were explored and goats shedding C. burnetii were identified by testing vaginal swabs taken at the goats’ first kidding using a com1 polymerase chain reaction assay. The first surge in the number of goats with IgM to C. burnetii was observed at week 9. Thus, a first vaccination not later than 8 weeks of age to control C. burnetii in highly contaminated environments is indicated. The odds of seroconversion were 2.0 times higher [95% confidence interval (CI) 1.2, 3.5] in kids born by does with serological evidence of recent infection (IgM seropositive) compared to kids born by IgM seronegative does, suggesting either in utero transmission or peri-parturient infection. The rate of seroconversion was 4.5 times higher (95% CI 2.1, 9.8) during than outside the kidding season, highlighting the risk posed by C. burnetii shed during kidding, even to goats outside the kidding herd. Shedding of C. burnetii at kidding was detected in 15 out of 41 goats infected before breeding.