Serology for Neosporosis, Q fever and Brucellosis to assess the cause of abortion in two dairy cattle herds in Ecuador

A first insight into seropositivity of Neospora caninum and associated risk factors in free-roaming dogs from Ecuador

Neosporosis is a worldwide parasitic disease caused by the protozoan Neospora caninum. It can cause economic losses to farmers due to its relationship with abortions and neonatal mortality in cows. Dogs play a key role in its spread as they are considered definitive hosts. In this study, we determined for the first time the seropositivity of N. caninum infection in dogs from Ecuador and evaluated potential risk factors. A total number of 339 free-roaming dogs from the three main regions of Ecuador (Coastal, Andean, and Amazonian regions) were included in the study and classified either as urban or rural dogs. Serum samples were collected from November 2018 to May 2019, and analyzed with a commercial ELISA test. An overall seropositivity of 6.8 % (CI: 95 %, 2.8 % - 11.7 %) was found in N. caninum infection with no statistical differences among regions or urban/rural dogs. This is the first surveillance of N. caninum in Ecuador, confirming a country-wide distribution of this pathogen. Considering the large populations of free-roaming dogs in Ecuador, a One Health approach for surveillance and managing N. caninum in dogs is needed to protect either livestock or wildlife.

An Overview of Infectious and Non-Infectious Causes of Pregnancy Losses in Equine

Equine breeding plays an essential role in the local economic development of many countries, and it has experienced rapid growth in China in recent years. However, the equine industry, particularly large-scale donkey farms, faces a significant challenge with pregnancy losses. Unfortunately, there is a lack of systematic research on abortion during equine breeding. Several causes, both infectious and non-infectious, of pregnancy losses have been documented in equines. The infectious causes are viruses, bacteria, parasites, and fungi. Non-infectious causes may include long transportation, ingestion of mycotoxins, hormonal disturbances, twinning, placentitis, umbilical length and torsion, etc. In current review, we discuss the transmission routes, diagnostic methods, and control measures for these infectious agents. Early detection of the cause and appropriate management are crucial in preventing pregnancy loss in equine practice. This review aims to provide a comprehensive understanding of the potential causes of abortion in equines, including infectious agents and non-infectious factors. It emphasizes the importance of continued research and effective control measures to address this significant challenge in the equine industry.

Prevalence, Risk Factors, and Relationship between Reproductive Performance and the Presence of Antibodies against Coxiellosis in Dairy Farm Milk Tanks in the Northwest of Spain

Q fever is a zoonotic disease that has been associated with reproductive problems in animals. As there is little epidemiological data regarding the distribution and risk factors of this disorder in cattle, the objective of this study was to evaluate the prevalence of Coxiella burnetii among dairy herds in the northwest of Spain, and to determine the on-farm risk factors associated with the disease and its effects on reproductive performance. Bulk tank milk (BTM) samples were collected from 262 commercial dairy herds from A Coruña, Lugo, and Pontevedra provinces. Data about location, mean age, and herd management features were obtained. A commercial indirect ELISA kit was used to determine the presence of antibodies against C. burnetii in BTM samples. The relationship between seropositivity to C. burnetii and the risk factors was checked using a Pearson's χ2 test and a classification tree analysis. In addition, a one-way ANOVA test and the Mann-Whitney U test were used to check the impact of seropositivity to C. burnetii on reproductive performance. A total of 60.1% of the farms tested positive for coxiellosis, the herd size, the external purchase of livestock, and the geographical area were identified as the main risk factors. Conception rate and first-service conception rate were significantly lower (p < 0.05) in positive farms (37.1 and 32.9%) compared to negative farms (39.8 and 36.1%). Similarly, positive farms had significant higher incidence of endometritis (13.7% vs. 11.2%, p < 0.05). Consequently, a high seropositivity and slightly negative effects of coxiellosis on reproductive performance were observed, which intensifies the need for further research, including the identification an active infection in positive herds and the characterization of the genotype.

A systematic review and meta-analysis of bovine brucellosis seroprevalence in Latin America and the Caribbean

Introduction

Bovine brucellosis is a significant public health problem in countries with economic and zoonotic implications. Although relevant, there are no previous systematic reviews about bovine brucellosis in Latin America.

Methods

We performed a systematic literature review in five data-bases to assess the seroprevalence of Brucella in cattle. A meta-analysis with a random-effects model was performed to calculate the pooled prevalence and 95% confidence intervals (95%CI). In addition, measures of heterogeneity (Cochran's Q statistic and I2 test) were reported.

Results

The literature search yielded 3,403 articles, of which 65 studies were fully valid for analysis. The pooled seroprevalence for Brucella in bovine (n ​= ​46,883,177) was 4.0% (95%CI: 3.0%-5.0%; p ​< ​0.001), and Venezuela was the country with the highest prevalence (16.0%). By regions, the highest seroprevalence is in Central America and the Caribbean islands (8.0%,95%CI: 3.0%-15.0%; p ​< ​0.001, I2 ​= ​99.85).

Conclusions

Some countries reported still relevant seroprevalences of bovine brucellosis, especially at the Central America and Caribbean islands. Multiple factors may influence the survival and spread of pathogens in the environment; farms located in regions bordering forest areas, in areas of difficult access to the veterinary service; extensive beef herds raised at pastures with different age and productive groups inter-mingled, and minimal concerns regarding hygiene practices and disease prevention measures. Bovine brucellosis has not been eliminated and needs to be considered with new tools for prevention and control, especially being a zoonosis.

Abattoir-based serological surveillance for transboundary and zoonotic diseases in cattle and swine in Cambodia: a pilot study in Phnom Penh province during 2019 and 2020

A pilot animal disease surveillance program was implemented at four abattoirs in Phnom Penh, Cambodia, between October 2019 and January 2020. A total of 1141 samples were collected from 477 cattle and 664 swine. Serological testing was performed using commercial antibody ELISA kits for zoonotic and high-impact animal diseases, namely brucellosis, Q fever, classical swine fever (CSF), porcine reproductive and respiratory syndrome (PRRS) and African swine fever (ASF). Only two samples tested positive for Brucella antibodies (0.2%, 95% CI 0.4-0.6, n = 1141). The seroprevalence of Q fever was 0.8% (95% CI 0.3-2.1, n = 477) in the cattle samples, while CSF, PRRS and ASF in pigs were 55.4% (95% CI 51.6-59.2, n = 655), 81.2% (95% CI 78.1-84.0, n = 655) and 2.6% (95% CI 1.6-4.1, n = 664), respectively. All 38 doubtful and 17 positive ASF antibody ELISA samples were negative when tested by real-time PCR. Univariate analyses demonstrated that the factor significantly associated with positive results of ASF was the abattoir location (p-value = 0.002). Based on logistic regression models, significant risk factors for CSF were province of origin (p-value = 1.7 × 10-6), abattoir (p-value = 3.6 × 10-11) and PRRS positivity (p-value = 0.004), and for PRRS were province of origin (p-value = 0.0004) and CSF positivity (p-value = 0.001). In conclusion, the seroprevalences of zoonotic diseases in this study were very low. The high prevalence of CSF and PRRS antibodies were most likely the result of vaccination. All ASF seropositive pigs, including those that gave equivocal results, originated from large-scale Cambodian-based commercial farms, as well as Thailand, which raises questions about possible illegal vaccination or low-pathogenicity ASF variants. The pilot abattoir serological surveillance program described here has the potential to provide a sentinel for incursions of novel and endemic pathogens, although further work is required to demonstrate its capacity to provide information on the longitudinal disease trends.

Apicomplexans in Goat: Prevalence of Neospora caninum, Toxoplasma gondii, Cryptosporidium spp., Eimeria spp. and Risk Factors in Farms from Ecuador

Simple Summary

Neospora caninum, Toxoplasma gondii, Cryptosporidium and Eimeria species are parasites of phylum Apicomplexa, which includes several protozoa affecting animals and humans. In Ecuador, the maintenance of goat health is a matter of utmost importance because it affects the economic welfare of the breeders. N. caninum and T. gondii cause reproductive problems in goats, leading to abortions or weak offspring. Severe diarrhea in kids and delays in growth are due to the Cryptosporidium and Eimeria species. Moreover, T. gondii and Cryptosporidium are zoonotic parasites with serious consequences for human health. The aim of this work was to determine, by serological and parasitological tests, the prevalence of these parasites and the risk factors for goat populations in Southern Ecuador. On some farms, the prevalence of N. caninum and T. gondii reached more than 50%; up to 17% of the kids were positive for Cryptosporidium and 90% of the goats were positive for the Eimeria species. The analysis of risk factors revealed differences according to the parasite species. Considering the zoonotic significance of these results, control and prevention measures are essential and constitute a warning to veterinarians and governmental institutions.

Abstract

Neospora caninum, Toxoplasma gondii, Cryptosporidium and Eimeria cause severe impacts on the productivity of goat herds. The objectives of the present study were to establish the prevalence of these apicomplexans in goat farms from Ecuador; to evaluate a rapid test for Cryptosporidium diagnosis and to identify the risk factors associated with the infections. A questionnaire was designed to obtain information from 24 goat farms from Zapotillo, Garza Real, Cazaderos, Limones and Paletillas parishes in Ecuador. Blood (n = 388) and feces (n = 391) samples were collected. Indirect ELISA and standard parasitological assays were carried out to evaluate the seroprevalence of N. caninum and T. gondii and to detect oocysts of Cryptosporidium and Eimeria. The overall prevalence values of N. caninum and T. gondii were 12.11% and 18.20%, Cryptosporidium spp. and Eimeria spp. oocysts were detected in 10.49% and 89.51% of the total samples. A low correlation value was found between the results obtained by Ziehl-Nielsen and the rapid test. The multinomial logistic regression analysis revealed that vitamin supplementation, age of diarrhea, frequency of deworming, pasture area, presence of artiodactyls, domestic fowl, administration of sulfas, age group, body condition, abortions, type of pastures and the presence of cattle were risk factors according to the parasite species.

Coxiella burnetii abortion in a dairy farm selling artisanal cheese directly to consumers and review of Q fever as a bovine abortifacient in South America and a human milk-borne disease

Coxiella burnetii is a highly transmissible intracellular bacterium with a low infective dose that causes Q fever (coxiellosis), a notifiable zoonotic disease distributed worldwide. Livestock are the main source of C. burnetii transmission to humans, which occurs mostly through the aerogenous route. Although C. burnetii is a major abortifacient in small ruminants, it is less frequently diagnosed in aborting cattle. We report a case of C. burnetii abortion in a lactating Holstein cow from a dairy farm producing and selling artisanal cheese directly to consumers in Uruguay, and review the literature on coxiellosis as a bovine abortifacient in South America and as a milk-borne disease. The aborted cow had severe necrotizing placentitis with abundant intratrophoblastic and intralesional C. burnetii confirmed by immunohistochemistry and PCR. After primo-infection in cattle, C. burnetii remains latent in the lymph nodes and mammary glands, with milk being a significant and persistent excretion route. Viable C. burnetii has been found in unpasteurized milk and cheeses after several months of maturing. The risk of coxiellosis after the consumption of unpasteurized dairy products, including cheese, is not negligible. This report raises awareness on bovine coxiellosis as a potential food safety problem in on-farm raw cheese manufacturing and sales. The scant publications on abortive coxiellosis in cattle in South America suggest that the condition has probably gone underreported in all countries of this subcontinent except for Uruguay. Therefore, we also discuss the diagnostic criteria for laboratory-based confirmation of C. burnetii abortion in ruminants as a guideline for veterinary diagnosticians.

The first report of seroprevalence of Q fever in water buffaloes (Bubalus bubalis) in Phatthalung, Thailand

Background and Aim:

Q fever is a worldwide zoonosis caused by the intracellular bacterium, Coxiella burnetii. A few studies focused on the occurrence of Q fever infection in water buffaloes in Thailand have been conducted; however, little is known regarding the seroprevalence of C. burnetii antibodies in buffaloes. In the present study, we describe the prevalence of Q fever infection in water buffaloes (Bubalus bubalis) in Phatthalung, Thailand.

Materials and Methods:

A total of 421 samples (156 blood, 156 sera, and 109 ectoparasites [lice]) were collected from 156 water buffaloes from 29 farms of the Phatthalung Province from January 22, 2021, to March 26, 2021. The blood and ectoparasite samples were screened for C. burnetii DNA using a polymerase chain reaction assay and the sera were tested for C. burnetii antibody using an indirect immunofluorescence assay.

Results:

C. burnetii DNA was not detected in blood or ectoparasites; however, the seroprevalence of individual water buffaloes was 4.49% (95% CI: 2.19-8.99%), whereas that of the herd was 13.79%. There was a significant difference between abortion history and Q fever infection at 29 farms (p=0.005; OR=33.55 [95%CI: 156-722.38]).

Conclusion:

This is the first report describing the low seroprevalence of C. burnetii antibodies in water buffaloes in Phatthalung Province, Thailand. The occurrence of this pathogen in buffaloes with reproductive disorders and people working with buffaloes warrant further investigation. Animal health authorities should inform farmers to effectively prevent and control this zoonosis.

The Development of an Abattoir-Based Surveillance System in Lao PDR for the Detection of Zoonoses in Large Ruminants: Q Fever and Brucellosis Seroepidemiology as a Pilot Study

Although animal health surveillance programmes are useful for gaining information to help improve global health and food security, these programmes can be challenging to establish in developing economies with a low-resource base. This study focused on establishing a national surveillance system initiated by the Lao PDR government using a passive surveillance system of abattoir samples as a pilot model, and to gain information on contagious zoonoses, particularly Q fever and brucellosis, in the large ruminant population. A total of 683 cattle and buffalo samples were collected from six selected provinces of Lao PDR between March-December 2019. Out of 271 samples tested, six samples (2.2%, 95% confidence interval (CI) of 1.0, 4.8) were positive in the Q fever antibody ELISA test. Only one sample (out of 683; 0.2%, 95% CI 0.0, 0.8) tested positive to the Brucella antibody ELISA test. Seroprevalence of these important zoonoses in Lao PDR were relatively low in cattle and buffaloes; however, extensive animal movement within the country was identified which could increase risks of spreading transboundary diseases. The study highlights the importance of ongoing animal health surveillance and the need to find cost-effective approaches for its long-term sustainability.

Sero-detection of Coxiella burnetii infection in cattle, sheep and goats in selected regions of Nepal

Coxiella burnetii, a Gram‐negative bacterium is a zoonotic agent causing coxiellosis in animals. Small ruminants and cattle are the primary reservoirs for human infection. This study was aimed to estimate the sero‐prevalence of C. burnetii in the ruminants of the selected region in Nepal. Field visits were carried out at four sites in different geographical regions of Nepal. A total of 522 sera samples were collected from 118 sheep, 242 goats and 162 cattle with the history of abortion, anoestrus and infertility. Sera were tested for the presence of antibodies against C. burnetii using a commercially available ready‐to‐use ELISA test kit. The overall true sero‐prevalence was 1.89% (95% CI: 0.33–3.45), the prevalence ranged between 4.35% and 23.21% in goats. Sero‐prevalence in goat was higher than that of cattle and sheep which ascertained that total freedom from coxiellosis cannot be confirmed in Nepal. This could complement the impacts of other infectious causes of the infertility in the farm animals as well as the public health of the farming households.

Serological and Molecular Phylogenetic Detection of Coxiella burnetii in Lactating Cows, Iraq

This study is carried out to investigate the prevalence of Coxiella burnetii (C. burnetii) infections in cattle using an enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) assay targeting IS1111A transposase gene. A total of 130 lactating cows were randomly selected from different areas in Wasit province, Iraq and subjected to blood and milk sampling during the period extended between November 2018 and May 2019. ELISA and PCR tests revealed that 16.15% and 10% of the animals studied were respectively positive. Significant correlations (P<0.05) were detected between the positive results and clinical data. Two positive PCR products were analyzed phylogenetically, named as C. burnetii IQ-No.5 and C. burnetii IQ-No.6; and then recorded in the National Center for Biotechnology Information (NCBI) under an accession numbers of MN473204.1 and MN473205.1. Comparative identity of the local strains with NCBI-BLAST strains/isolates revealed 97% similarity and 0.1-0.6% of total genetic mutations/changes. NCBI-BLAST Homology Sequence reported high significant identity (P<0.05) between the local, C. burnetii IQ-No.5 and C. burnetii IQ-No.6; strains and C. burnetii 3345937 (CP014354.1) Netherlands isolate at 99.10% and 99.06%, respectively. The current study concluded that the percentage of infected cows with coxiellosis is relatively high, and Coxiella should be listed as abortive pathogen. Therefore, additional studies should be performed including different animals, samples, and regions.

Establishment of Novel High-Standard Chemiluminescent Assay for NTPase in Two Protozoans and Its High-Throughput Screening

Toxoplasma gondii is a major protozoan parasite and infects human and many other warm-blooded animals. The infection leads to Toxoplasmosis, a serious issue in AIDS patients, organ transplant recipients and pregnant women. Neospora caninum, another type of protozoa, is closely related to Toxoplasma gondii. Infections of the protozoa in animals also causes serious diseases such as Encephalomyelitis and Myositis-Polyradiculitis in dogs or abortion in cows. Both Toxoplasma gondii and Neospora caninum have similar nucleoside triphosphate hydrolases (NTPase), NcNTPase and TgNTPase-I in Neospora caninum and Toxoplasma gondii, respectively. These possibly play important roles in propagation and survival. Thus, we targeted the enzymes for drug discovery and tried to establish a novel high-standard assay by a combination of original biochemical enzyme assay and fluorescent assay to determine ADP content. We then validated whether or not it can be applied to high-throughput screening (HTS). Then, it fulfilled criterion to carry out HTS in both of the enzymes. In order to identify small molecules having inhibitory effects on the protozoan enzyme, we also performed HTS using two synthetic compound libraries and an extract library derived from marine bacteria and then, identified 19 compounds and 6 extracts. Nagasaki University collected many extracts from over 18,000 marine bacteria found in local Omura bay, and continues to compile an extensive collection of synthetic compounds from numerous drug libraries established by Japanese chemists.

Neospora caninum infection in dairy farms with history of abortion in West of Iran

Neospora caninum is a major cause of abortion and economic losses among dairy farms in Iran and other countries. The main goal of current investigation was to evaluate the presence of antibodies against N. caninum and associated risk factors in dairy herds with history of abortion in Hamedan province of West Iran. A total numbers of 476 and 185 blood samples of pregnant cattle and farm dogs from 10 dairy farms with history of abortion were randomly collected. Bulk milk sample was taken from each farm. All samples were subjected for detection of IgG antibody against N. caninum using ELISA technique. Of all examined animals, 24.8% of cattle and 8.65% of dogs were seropositive to N. caninum. The seroprevalence had significant differences with abortion, stillbirth, metritis, breed, close contact to dogs, wild carnivores, rodents, poultry, and pregnancy using artificial insemination method. There were no significant differences among seroprevalence and different age groups, number and stage of gestation, and herd population. In all investigated farms, bulk milk examination was positive. In examined dogs, there was significant difference between seroprevalence and sex. It was concluded that N. caninum infection may be responsible for abortion and economic losses in dairy farms of the region. This was also the first comprehensive report on associated risk factors to N. caninum infection in dairy farms in the region.