Molecular identification, risk factor assessment, and phylogenetic analysis of tick-borne pathogens in symptomatic and asymptomatic cattle from South-Eastern Iran

Tick-borne pathogens (TBPs) represent a substantial threat to cattle globally, exerting adverse impacts on production, health, and economic viability. This study delves into the prevalence and implications of TTBPs in cattle sourced from resource-limited smallholder livestock farms situated in southeastern Iran, proximate to Afghanistan and Pakistan. Blood and tick specimens were systematically collected from a cohort of 230 cattle, comprising 150 asymptomatic and 80 symptomatic individuals. Genomic DNA isolated from blood samples underwent rigorous examination for the presence of key TBPs, including Anaplasma marginale, A. phagocytophilum, A. bovis, A. centrale, Babesia bigemina, and Theileria annulata, utilizing multiple genetic markers. Nucleotide sequence analysis facilitated the reconstruction of phylogenetic relationships. The study also evaluated various potential risk factors, such as clinical status, gender, age, breed, tick infestation, and management practices, to elucidate their associations with TTBPs. Among the cattle cohort, a staggering 87.8% (202/230) tested positive for at least one pathogen. Prevalence statistics encompassed A. marginale (72.2%), T. annulata (68.3%), A. phagocytophilum/A. platys-like complex (66.1%), A. centrale (16.7%), B. bigemina (10.0%), and A. bovis (6.1%). Remarkably, mixed infections involving two, three, and four pathogens were detected in 23%, 52.1%, and 2.2% of animals, respectively. Notably, all asymptomatic cattle were positive for at least one TBP. Tick infestation was observed in 62.2% (143/230) of cattle, predominantly caused by Hyalomma anatolicum (82.5%), Rhipicephalus (Boophilus) annulatus (13.1%), and R. sanguineus sensu lato (4.4%). Risk factors linked to TBPs encompassed tick infestation, older age, and crossbred animals. Clinical presentations among symptomatic cattle encompassed fever, anemia, weight loss, anorexia, jaundice, and enlarged superficial lymph nodes. This study underscores the pivotal role of asymptomatic carriers in the propagation of TTBPs within endemic regions. Furthermore, it emphasizes the potential for the implementation of molecular diagnostics to unmask subclinical infections, thereby affording the opportunity for targeted interventions aimed at ameliorating the burden of TTBPs in resource-constrained smallholder dairy farms.

First detection of hepatitis E virus in dromedary camels from Iran

BACKGROUND

Hepatitis E virus (HEV) genotype 7 is a zoonotic disease detected in dromedary camels.

HYPOTHESIS/OBJECTIVES

The consumption of camel meat and dairy products, the abundance of dromedary camels in Southeast Iran and the import of camels from neighbouring countries to Iran made the researchers investigate the infection rate of camels by the virus.

ANIMALS

A total of 53 healthy camels in Southeast Iran (Sistan and Baluchistan Province) tested for HEV RNA.

METHOD

A total of 17 blood samples and 36 liver samples were taken from 53 healthy dromedary camels (aged between 2 and 10 years) from various southeastern regions of Iran. The samples were tested for HEV using RT-PCR.

RESULTS

Overall, 56.6% of the studied samples (n = 30) tested positive for HEV RNA.

CONCLUSIONS AND CLINICAL IMPORTANCE

The present study was the first of its kind in Iran and revealed the presence of HEV in the Iranian dromedary camel population, which might play the role of a zoonosis reservoir for its transmission to humans. This discovery raises concerns about food-borne illnesses that can be transmitted from animals to humans. However, further research is needed to identify the specific genotype of the HEV in Iranian dromedary camel infections and to determine the risk of spread to other animals and humans.

First detection of Schmallenberg virus antibody in cattle population of eastern Iran

Schmallenberg virus (SBV) is an emerging single-stranded RNA virus being classified under Simbu serogroup of Bunyaviridae family. This study aimed to detect antibodies against SBV in cattle for the first time in three eastern provinces of Iran. Blood samples were randomly collected from jugular veins of 273 cattle, from 19 farms in Razavi Khorasan, South Khorasan and Sistan and Baluchestan provinces. Separated sera were analyzed to find SBV antibody using ID vet^® SBV indirect multi-species enzyme-linked immunosorbent assay test kit. From a total of 273 serum samples analyzed for SBV presence, 12.45% (n = 34) were positive for SBV antibody. Risk factors including breed, age and geographic area showed a statistically significant relationship with the virus prevalence. In conclusion, the seroprevalence of SBV is not high; but it is considerable in the studied parts of Iran. This is the first study regarding SBV seroprevalence in cattle population of eastern Iran and further studies about the virus epidemiology are recommended.

Identification of Anaplasma marginale in long-eared hedgehogs (Hemiechinus auritus) and their Rhipicephalus turanicus ticks in Iran

Hedgehogs play a role in the eco-epidemiology of parasites, viruses and bacteria of veterinary and medical importance. In Europe, hedgehogs have been found infected with tick-transmitted Anaplasma phagocytophilum and A. marginale. In this study blood and ticks collected from 53 long-eared hedgehogs (Hemiechinus auritus) living in southeastern Iran close to Afghanistan and Pakistan borders were examined for Anaplasma spp. infection using microscopical and molecular biology methods. At microscopical examination Anaplasma-like inclusion bodies were found at the margin of erythrocytes in the blood smear of one infected hedgehog (prevalence 1.9 %). Each hedgehog was infested with three to eight adult ticks (average 4.7 ± 1.5). On the body of hedgehogs, the ears were the main site for attachment of ticks. Out of 248 collected adult ticks 81.4 % were Rhipicephalus sanguineus sensu lato and 18.5 % were R. turanicus. PCR and sequencing showed the presence of A. marginale infection in the blood of two hedgehogs (3.8 %) and R. turanicus ticks collected from them. This is the first report of A. marginale infection in hedgehogs in Iran. Epidemiological importance of this finding is discussed and current knowledge on the tick fauna of hedgehogs in the country is reviewed.

Epidemiology, risk factors, and co-infection of vector-borne pathogens in goats from Sistan and Baluchestan province, Iran

Several vector-borne pathogens restrict livestock farming and have significant economic impact worldwide. In endemic areas livestock are exposed to different tick species carrying various pathogens which could result in co-infection with several tick-borne pathogens in a single host. Although the co-infection of and the interaction among pathogens are critical factors to determine the disease outcome, pathogen interactions in the vector and the host are poorly understood. In this study, we surveyed the presence of Babesia ovis, Theileria ovis, Theileria lestoquardi, Anaplasma ovis, Anaplasma phagocytophilum, and Anaplasma marginale in 200 goats from 3 different districts in Sistan and Baluchestan province, Iran. Species-specific diagnostic PCRs and sequence analysis revealed that 1.5%, 12.5%, and 80% of samples were positive for T. lestoquardi, T. ovis, and A. ovis, respectively. Co-infections of goats with up to 3 pathogens were seen in 22% of the samples. We detected a significant association between T. ovis infection and age, T. ovis infection and location (Zabol), and A. ovis infection and location (Sarbaz) by multivariate logistic regression analysis. In addition, by analyzing the data with respect to Plasmodium caprae infection in these goats, a negative correlation was found between P. caprae and A. ovis infection. This study contributes to understanding the epidemiology of vector-borne pathogens and their interplay in goats.

Detection of Schmallenberg virus antibody in equine population of Northern and Northeast of Iran

Aim:

Schmallenberg virus (SBV) is a newly emerging virus in Simbu group that 1^st time is reported in 2011 in Germany and now spread to Europe. The clinical signs of infection to this virus are fever, loss of appetite, reduced milk yield and in some cases, diarrhea and in pregnant animals congenital malformations in calves, lambs, and kid goats.

Materials and Methods:

In this study for a serologic survey of SBV, blood samples from 200 horse in different rural areas of the northern and northeast of Iran with the high equine population collected and were analyzed using an indirect ELISA test.

Results:

Based on our results 5% (n=10) of total 200 samples were positive for SBV antibody and 2% (n=4) was doubtful and 93% (n=186) was negative. There were no significant differences between age and sex and breed properties (p>0.05).

Conclusion:

This study demonstrated the presence of antibodies against the SBV on horse populations in Iran. The high population and activity of Culicoides biting midges and their proper living conditions, especially the areas of temperate and humid environmental conditions, are the possible causes of arboviruses related diseases seen in this country.