Seroprevalence and molecular characterization of West Nile Virus in Egypt

The key role of Spain in the traffic of West Nile virus lineage 1 strains between Europe and Africa

BACKGROUND

West Nile Virus (WNV) is a zoonotic arbovirus worldwide spread. Seasonal WNV outbreaks occur in the Mediterranean basin since the late 1990's with ever-increasing incidence. In Southern Spain WNV is endemic, as disease foci - caused by WNV lineage 1 (WNV-L1) strains - occur every year. On the contrary, WNV-L2 is the dominant lineage in Europe, so most European WNV sequences available belong to this lineage, WNV-L1 sequences being still scarce.

METHODS

To fill this gap, this study reports the genetic characterisation of 27 newly described WNV-L1 strains, involved in outbreaks affecting wild birds and horses during the last decade in South-Western Spain.

RESULTS

All strains except one belong to the Western Mediterranean-1 sub-cluster (WMed-1), related phylogenetically to Italian, French, Portuguese, Moroccan and, remarkably, Senegalese strains. This sub-cluster persisted, spread and evolved into three distinguishable WMed-1 phylogenetic groups that co-circulated, notably, in the same province (Cádiz). They displayed different behaviours: from long-term persistence and rapid spread to neighbouring regions within Spain, to long-distance spread to different countries, including transcontinental spread to Africa. Among the different introductions of WNV in Spain revealed in this study, some of them succeeded to get established, some extinguished from the territory shortly afterwards. Furthermore, Spain's southernmost province, Cádiz, constitutes a hotspot for virus incursion.

CONCLUSION

Southern Spain seems a likely scenario for emergence of exotic pathogens of African origin. Therefore, circulation of diverse WNV-L1 variants in Spain prompts for an extensive surveillance under a One Health approach.

Synthesis of eco-friendly layered double hydroxide and nanoemulsion for jasmine and peppermint oils and their larvicidal activities against Culex pipiens Linnaeus

Mosquito-borne diseases represent a growing health challenge over time. Numerous potential phytochemicals are target-specific, biodegradable, and eco-friendly. The larvicidal activity of essential oils, a jasmine blend consisting of Jasmine oil and Azores jasmine (AJ) (Jasminum sambac and Jasminum azoricum) and peppermint (PP) Mentha arvensis and their nanoformulations against 2nd and 4th instar larvae of Culex pipiens, was evaluated after subjecting to different concentrations (62.5, 125, 250, 500, 1000, and 2000 ppm). Two forms of phase-different nanodelivery systems of layered double hydroxide LDH and oil/water nanoemulsions were formulated. The synthesized nanoemulsions showed particle sizes of 199 and 333 nm for AJ-NE and PP-NE, with a polydispersity index of 0.249 and 0.198, respectively. Chemical and physiochemical analysis of TEM, SEM, XRD, zeta potential, drug loading capacity, and drug release measurements were done to confirm the synthesis and loading efficiencies of essential oils' active ingredients. At high concentrations of AJ and PP nanoemulsions (2000 ppm), O/W nanoemulsions showed higher larval mortality than both LDH conjugates and crude oils. The mortality rate reached 100% for 2nd and 4th instar larvae. The relative toxicities revealed that PP nanoemulsion (MA-NE) was the most effective larvicide, followed by AJ nanoemulsion (AJ-NE). There was a significant increase in defensive enzymes, phenoloxidase, and α and β-esterase enzymes in the treated groups. After treatment of L4 with AJ, AJ-NE, PP, and PP-NE, the levels of phenoloxidase were 545.67, 731.00, 700.00, and 799.67 u/mg, respectively, compared with control 669.67 u/mg. The activity levels of α-esterase were 9.71, 10.32, 8.91, and 10.55 mg α-naphthol/min/mg protein, respectively. It could be concluded that the AJ-NE and PP-NE nanoformulations have promising larvicidal activity and could act as safe and effective alternatives to chemical insecticides.

The Global Epidemiology of Bovine Leukemia Virus: Current Trends and Future Implications

Bovine leukemia virus (BLV) is a retrovirus that causes enzootic bovine leucosis (EBL), which is the most significant neoplastic disease in cattle. Although EBL has been successfully eradicated in most European countries, infections continue to rise in Argentina, Brazil, Canada, Japan, and the United States. BLV imposes a substantial economic burden on the cattle industry, particularly in dairy farming, as it leads to a decline in animal production performance and increases the risk of disease. Moreover, trade restrictions on diseased animals and products between countries and regions further exacerbate the problem. Recent studies have also identified fragments of BLV nucleic acid in human breast cancer tissues, raising concerns for public health. Due to the absence of an effective vaccine, controlling the disease is challenging. Therefore, it is crucial to accurately detect and diagnose BLV at an early stage to control its spread and minimize economic losses. This review provides a comprehensive examination of BLV, encompassing its genomic structure, epidemiology, modes of transmission, clinical symptoms, detection methods, hazards, and control strategies. The aim is to provide strategic information for future BLV research.

Serosurvey and associated risk factors for Neospora caninum infection in Egyptian water buffaloes (Bubalus bubalis)

Neosporosis is a parasitic disease that causes reproductive disorders in animals, making it a barrier to maximum efficiency. The purpose of this study was to determine the seroprevalence of Neospora caninum (N. caninum) antibodies in water buffaloes from four governorates in northern Egypt. A commercial indirect-ELISA test was used to detect antibodies against N. caninum in the serum of 450 water buffaloes. The total seroprevalence of N. caninum in water buffaloes from Egypt was 31.3%, and the highest prevalence was observed in Gharbia governorate. The identified risk factors for N. caninum infections in water buffaloes were sex (OR = 1.96, 95%CI: 1.22-4.17), buffaloes more than 4 years of age ( OR = 5.80, 95%CI: 2.26-14.86), abortion in second trimester (OR = 16.48, 95%%CI: 2.99-34.03), history of abortion (OR = 3.45, 95%CI: 1.58-7.52) and contact with dogs (OR = 2.55, 95%CI: 1.51-4.32). Thus, more studies are needed to determine the role of buffaloes in the epidemiology of neosporosis in Egypt.

Molecular detection and phylogenic characterization of Neospora caninum in naturally infected sheep in Alborz and Qazvin provinces, the north of the central region of Iran

Neospora caninum is a protozoan coccidian parasite that can act as a cause of abortion in sheep. The aim of this study was to investigate the presence of this parasitic agent and its role in causing abortion in sheep of Iran. Between June 2019 and February 2022, 100 samples [brain (n = 39), placenta (n = 8), embryonic membrane (n = 7), cotyledon (n = 7), umbilical cord (n = 2), homogenate mixture of tissues (heart, liver, spleen and digestive track) (n = 37)] that were collected following the necropsies of 39 aborted ovine fetuses from different parts of the Alborz and Qazvin provinces, the north of the central region of Iran were employed for DNA extraction. Nc-5 was selected as the target gene sequence for amplification of DNA by using four pairs of primers in two semi-nested PCR. Samples considered positive for the presence of the NC-5 gene were examined to further confirm the presence of the ITS1 gene. Sequence of NC-5 gene was detected from the 27 tissue samples of 23 aborted ovine fetuses. The ITS1 gene sequence was detected in all of the 27 tissue samples that were positive for the NC-5 gene analysis. Brain tissue was the most studied tissue, and the highest number of positive cases was observed in this tissue. The present study updated the situation of ovine neosporosis in the central region of Iran and confirmed the presence of the N. caninum among sheep flocks' abortion.

Seroprevalence of Rift Valley Fever virus in one-humped camels (Camelus dromedaries) in Egypt

Rift Valley fever (RVF) is a mosquito-borne viral disease that affects a variety of domestic animals, including cattle, sheep, goats, and camels, and has zoonotic potential. Although the rift valley fever virus (RVFV) is usually asymptomatic in camels, it can induce abortion in some pregnant animals. In the current study, a serosurvey was carried out to investigate the prevalence of RVFV antibodies and related risk factors in camels from four Egyptian governorates. A total of 400 serum samples were examined for anti-RVFV antibodies using a competitive enzyme-linked immunosorbent assay (c-ELISA). The results revealed that the overall prevalence of RVF among examined camels was 21.5% and the disease was more prevalent in Kafr ElSheikh governorate in Nile Delta of Egypt. In addition, the age group of camels with more than 5 years (OR=4.49, 95%CI: 1.39-14.49), the female sex (OR=3.38, 95%CI: 1.51-7.58), the emaciated animals (OR=1.52, 95%CI: 0.86-2.66), the summer season's infection (OR=5.98, 95%CI: 1.79-19.93), the presence of mosquitoes (OR= 2.88, 95%CI: 1.39-5.95), and the absence of mosquitoes control (OR=3.97, 95%CI: 2.09-7.57) were identified as risk factors for RVFV infection. The results of this study support knowledge on the risk factors for RVFV infection and demonstrate that camels raising in Egypt have RVFV antibodies. Quarantine measures or vaccination program should be implemented to reduce the likelihood of RVFV introduction, dissemination among susceptible animals, and ultimately transmission to humans.

Neospora caninum infection in dairy cattle in Egypt: a serosurvey and associated risk factors

Neospora caninum (N. caninum) is one of the causative agents that causing cattle abortion, and severe economic losses. Due to the scarcity of data on N. caninum infection in Egyptian cattle, the purpose of this study was to estimate the seroprevalence and determine the risk factors for parasite infection. In four governorates in northern Egypt, 540 blood samples from cattle were taken, and tested using a commercial ELISA kit. The overall seroprevalence of N. caninum in examined cattle was 28.89%. A multivariate logistic regression model determined that age (OR = 2.63, P < 0.001), manual milking (OR = 1.39, P = 0.14), abortion history (OR = 2.78, P < 0.0001), repetition of estrus (OR = 2.31, P < 0.0001), and contact with dogs (OR = 2.57, P < 0.0001) were significant risk factors. The findings proved that N. caninum infection was one of the factors contributing to abortion and financial losses in dairy cattle in Egypt. Therefore, the application of sanitary security and control programs is very important in dairy farms.

Effect of nanostructure lipid carrier of methylene blue and monoterpenes as enzymes inhibitor for Culex pipiens

Solid lipid nanoparticles second generation, nanostructure lipid carrier (NLC), is one of the most important biodegradable nanoparticles. Nanostructure Lipid carrier (NLC) was used to encapsulate methylene blue (MB) dye, carvacrol and citronellal and their efficacy as insecticidal against Culex pipiens (Cx. pipiens) were distinguished. The prepared nanoformulation revealed very good physicochemical properties, especially the homogeneity of the particle size. Transmission electron microscope showed spherical shaped nanoparticles within range less than 200 nm. The prepared NLC-MB-MT system showed a very competitive insecticidal activity and high virulence against the mosquito larvae with higher mortality rate of LC50 of 0.141 µl/mL, in addition to high level of Oxidative stress parameters obtained through all the tested enzymes including hydrogen peroxide (4.8 ppm), protein carbonyl amount (0.12 OD/mg protein), ascorbic acid (0.15 mg) and Superoxide dismutase (SOD) showed strong increasing (0.09 OD/mg protein/min) at 6 µg/mL, respectively. Whereas paradoxical results of the oxidative stress enzymes were obtained from different concentration of nanoformulation that introduce a convenient reason for their potential insecticidal effect. The cytotoxic effect of NLC-MB-MT was evaluated using WI38 human lung cell lines, the LC50 was 6.4 mg/mL. The low cytotoxic reactivity towards the tested cell line makes the NLC-MB-MT nanoformulation has its promising insecticidal efficacy. Molecular docking study for each component were done against acetylcholine esterase protein and accepted binding modes achieved by the three compounds.

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

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

Coxiella burnetii and its risk factors in cattle in Egypt: a seroepidemiological survey

Animal production is greatly affected by Q fever. As a result of a lack of methodology and financial means to perform extensive epidemiological surveys, the disease's underdiagnosis has proven to be a challenge for effective control. The present study aimed to determine the seroprevalence of C. burnetii in cattle raising in four governorates situated at Nile Delta of Egypt and assess the associated risk factors for infection. A total of 480 serum samples were collected from cattle and examined for presence of anti-C. burnetii antibodies using indirect ELISA assay. The overall seroprevalence of C. burnetii among examined cattle was 19.8%, with the Qalyubia governorate having the highest prevalence. The results of multivariable logistic regression analysis revealed significant association between C. burnetii seropositivity and age, communal grazing and/or watering, contact with small ruminants and history of infertility. According to the findings of this work, C. burnetii is circulating among cattle living in Nile Delta. It is suggested that adequate hygiene procedures and biosecurity measures should be implemented to limit the transmission of pathogens within cow herds and potential human exposure.

Sero-survey of bovine herpes virus-1 in dromedary camels and associated risk factors

Infectious bovine rhinotracheitis (IBR) is a major animal health hazard in many countries throughout the world, caused by bovine herpesvirus-1 (BoHV-1). The study’s goal was to evaluate the prevalence of BoHV-1 seropositivity among dromedary camels in three governorates in northern Egypt, as well as to identify risk variables related with BoHV-1 seropositivity. A total of 321 blood samples were collected randomly from dromedary camels living in the selected governorates and examined for presence of BoHV-1 antibody using ELISA test. The overall seroprevalence of BoHV-1 among examined camels was 5.92% (95%CI: 3.82–9.06). Univariable analysis confirmed that the significant association (P < 0.05) between sex, history of abortion, contact with small ruminants and herd size and BoHV-1 seropositivity. Using multiple logistic regression analysis, the following risk factors were identified to be related with the presence of BoHV-1 infection: sex (OR = 2.54, 95%CI: 0.63–10.22), history of abortion (OR = 4.16, 95%CI: 1.30–13.27), contact with small ruminants (OR = 5.61, 95%CI: 1.67–18.80) and large herd size (OR = 10.52, 95%CI: 2.46–44.91). This study estimated the disease’s seroprevalence in Egyptian dromedary camels, implying that camels could act as a BoHV-1 reservoir for transmission to other species.

A survey of bluetongue infection in one-humped camels (Camelus Dromedarius); seroprevalence and risk factors analysis

Bluetongue (BT) is an insect-borne, non-contagious viral disease which affects domestic ruminants including camels and is transmitted by Culicoides spp. Clinical symptoms of BT are typically seen in sheep, although subclinical BT infections are mostly seen in cattle, goats, and camelids. The goal of the present study was to evaluate the sero-prevalence of Bluetongue virus (BTV) in camels from some governorates in Egypt's southern and northern regions, as well as the infection's potential risk factors. During 2020-2021, a cross sectional study was conducted to screen presence of anti-BTV antibodies in 400 serum samples, which were collected randomly from camels, examined using competitive enzyme-linked immunosorbent assay (cELISA). The sera of 102 out of 400 camels tested positive for BTV, representing a frequency of 25.5%. Moreover, the odds of sero-positivity were higher among camels living in Aswan (OR = 5.33, 95%CI: 2.35-12.11), especially in females (OR = 2.63, 95%CI = 1.44-4.09) during summer season (OR = 2.40, 95%CI = 1.20-4.81). Furthermore, the probability of getting BTV infection increased when camels were exposed to the insect vectors (OR = 1.63, 95%CI = 0.87-3.09). The high prevalence of BTV in camels in several Egyptian regions highlights the need for more epidemiological investigations of BTV infection in other ruminant species in order to better control BT disease in these regions.

Epidemiology of Mosquito-Borne Viruses in Egypt: A Systematic Review

There are at least five common mosquito-borne viruses (MBVs) recorded in Egypt, including dengue virus (DENV), Rift Valley fever virus (RVFV), West Nile virus (WNV), Chikungunya virus, and Sindbis virus. Unexpected outbreaks caused by MBVs reflect the deficiencies of the MBV surveillance system in Egypt. This systematic review characterized the epidemiology of MBV prevalence in Egypt. Human, animal, and vector prevalence studies on MBVs in Egypt were retrieved from Web of Science, PubMed, and Bing Scholar, and 33 eligible studies were included for further analyses. The monophyletic characterization of the RVFV and WNV strains found in Egypt, which spans about half a century, suggests that both RVFV and WNV are widely transmitted in this nation. Moreover, the seropositive rates of DENV and WNV in hosts were on the rise in recent years, and spillover events of DENV and WNV to other countries from Egypt have been recorded. The common drawback for surveillance of MBVs in Egypt is the lack of seroprevalence studies on MBVs, especially in this century. It is necessary to evaluate endemic transmission risk, establish an early warning system for MBVs, and develop a sound joint system for medical care and public health for managing MBVs in Egypt.

Molecular epidemiology and genetic characterization of Theileria orientalis in cattle

Theileria orientalis (T. orientalis) is a benign species of Theileria that is found all throughout the world, including Egypt. The purpose of this work was to determine the current status of T. orientalis infection in cattle, as well as to define T. orientalis genetic diversity using the major piroplasm surface protein (MPSP) genes. In 2020, blood samples from 500 asymptomatic cattle were collected, which live in four different governorates at northern Egypt and examined using PCR assay based on MPSP gene. Overall, 44 blood samples (8.8%, 44/500) were positive for T. orientalis, and the highest prevalence rate was observed in Kafer ElSheikh while it was relatively low in Gharbia governorate. Moreover, based on multivariable analysis, the risk of infection with T. orientalis infection was higher in mixed breed cattle and in animals of age group more than 3 years compared to other. Additionally, absence of acaricide application, infestation with ticks, and communal grazing system were identified as potential risk factors for T. orientalis infection. Phylogenetic analysis revealed that the isolates studied belonged to two MPSP genotypes, types 1 and 2. These findings reveal that the MPSP genotypes discovered in the present work displayed genetic variation that was linked to geographic area. Therefore, further research should be focused on developing an effective T. orientalis monitoring and preventive program.

The first study on the seroprevalence of Anaplasma spp. in small ruminants and assessment of associated risk factors in North Egypt

Background and Aim

Ovine anaplasmosis is a rickettsial disease caused by Anaplasma spp. These Gram-negative intracellular bacteria are mainly transmitted by ticks and infected blood cells of caprine, ovine, and wild small ruminants. At present, epidemiological data on anaplasmosis in cattle, dogs, and camels in Egypt are available, but the data about Anaplasma spp. in sheep and goat are scarce. This study aimed to determine the seroprevalence of Anaplasma spp. in small ruminants and assess the associated risk factors.

Materials and Methods

A cross-sectional study was performed to investigate the seroprevalence of Anaplasma spp. in 300 sheep and 300 goats from four governorates in North Egypt using a commercial competitive enzyme-linked immunosorbent assays kit, and the associated risk factors for the infection were evaluated.

Results

Overall, the seroprevalence of anti-Anaplasma antibodies was 18.3% and 21.3% in sheep and goats, respectively. A multivariable logistic regression model was used to determine the association between risk factors and Anaplasma spp. infection.

Conclusion

Age, animal husbandry, acaricide use, tick infestation, and contact with cattle were the primary risk factors for Anaplasma seropositivity. This study confirms the presence of antibodies against Anaplasma spp. in small ruminants from Egypt. This is the first study to assess the associated risk factors for Anaplasma infection in small ruminants from Egypt. Further studies are needed to improve the understanding of the associated disease factors, facilitating the development of new procedures for control of anaplasmosis in livestock.

Molecular epidemiological survey, genetic characterization and phylogenetic analysis of Anaplasma ovis infecting sheep in Northern Egypt

Anaplasma ovis is the most common etiologic agent of ovine anaplasmosis, mainly transmitted by ticks. The present study aimed to determine the molecular prevalence of A. ovis in sheep from Egypt and assessed the associated risk factors. The study was conducted, between January and December 2020, in four governorates situated in Northern Egypt. Blood samples from 355 asymptomatic sheep were collected and examined by the use of PCR specific to A. ovis. Diversity analysis and phylogenetic study based on partial msp4 gene sequence were performed on revealed A. ovis DNA. Overall, the molecular prevalence rate of A. ovis was 15.5% and the highest rate was observed in Kafr ElSheikh governorate (16.8%). Statistical analysis revealed that A. ovis infection was significantly related to sheep gender and to tick infestation. The risk factors that were found to be associated with A. ovis infection in exposed sheep were: female sex (OR=2.6, 95%CI: 1.13-6.12), and infestation with ticks (OR=2.1, 95%CI: 1.11-3.79). The analysis of A. ovis msp4 sequences revealed two different genotypes classified in the Old World sub-cluster with other Egyptian isolates. Investigation on prevalence, risk factors and genetic variability of A. ovis in sheep reported in this study is important for the implementation of control programs. Further studies are needed to determine the vectors and reservoirs of A. ovis in Egyptian small ruminants and to identify the real economic impact of A. ovis infection on the country.

Prevalence and risk factors associated with tropical theileriosis in Egyptian dairy cattle

Background and Aim:

Theileria annulata is the most prevalent piroplasm infecting cattle across Egypt. Theileriosis is transmitted by ixodid ticks of the genus Hyalomma. This study aimed to estimate the prevalence of theileriosis in cattle and their associated risk factors for infection.

Materials and Methods:

A total of 570 blood samples were collected from cattle from five governorates (administrative districts) in Egypt and examined using a polymerase chain reaction assay to estimate the prevalence of tropical theileriosis and assess the associated risk factors

Results:

The overall prevalence rate was 16.49%, with the Alexandria district having the highest prevalence. The results revealed that the risk of theileriosis was elevated in older cattle (odds ratio [OR]=8.9, 95% confidence interval [CI]: 3.6-21.9), especially in summers (OR=3.07, 95% CI: 1.4-6.3). Cattle heavily infested with ticks were at particular risk (OR=3.05, 95% CI: 2.1-4.5), as were those to which acaricide had not been applied (OR=13.7, 95% CI: 5.6-33.6).

Conclusion:

Understanding the risk factors associated with T. annulata infection and regular infection monitoring could reduce infection rates and economic losses and is essential for the implementation of efficient control programs.

Nanostructured Lipid Carriers (NLC) for Biologically Active Green Tea and Fennel Natural Oils Delivery: Larvicidal and Adulticidal Activities against Culex pipiens

(1) Background: The control of mosquitoes with essential oils is a growing demand. (2) Methods: This study evaluated the novel larvicidal and adulticidal activity of fennel and green tea oils and their nanostructured lipid carriers (NLC) against Culex pipiens (C. pipiens) in the laboratory, field conditions and evaluated their effect against non-target organisms. SLN type II nanoformulations were synthesized and characterized using dynamic light scattering (DLS), zeta potential and transmission electron microscope. (3) Results: The synthesized NLCs showed spherical shaped, homogenous, narrow, and monomodal particle size distribution. The mortality percent (MO%) post-treatment (PT) with 2000 ppm for 24 h with fennel oil and NLC fennel (NLC-F) reached 85% (LC50 = 643.81 ppm) and 100% (LC50 = 251.71), whereas MO% for green tea oil and NLC green tea (NLC-GT) were 80% (LC50 = 746.52 ppm) and 100% (LC50 = 278.63 ppm), respectively. Field trial data showed that the larval reduction percent of fennel oil and NLC-F reached 89.8% and 97.4%, 24 h PT and the reduction percent of green tea oil and NLC-GT reached 89% and 93%, 24 h PT with persistence reached 8 and 7 days, for NLC-F and NLC-GT, respectively. The adulticidal effects showed that NLC-F and NLC-GT (100% mortality) were more effective than fennel and green tea oils (90.0% and 83.33%), with 24 h PT, respectively. Moreover, their reduction of adult density after spraying with LC95 X2 for 15 min, with fennel oil, NLC-F, and green tea oil, NLC-GT were 83.6%, 100%, 79.1%, and 100%, respectively, with persistence (>50%) lasting for three days. The predation rate of the mosquitofish, Gambusia affinis, and the bug, Sphaerodema urinator, was not affected in both oil and its NLC, while the predation rate of the beetle, Cybister tripunctatus increased (66% and 68.3%) by green tea oil and NLC-GT, respectively. (4) Conclusions: NLCs nanoformulation encapsulated essential oils was prepared successfully with unique properties of size, morphology, and stability. In vitro larvicidal and adulticidal effects against C. pipiens supported with field evaluations have been performed using essential oils and their nanoformulations. The biological evaluation of nanoformulations manifested potential results toward both larvicidal and adulticidal compared to the essential oils themselves, especially NLC encapsulated fennel oil which had promising larvicidal and adulticidal activity.

Larvicidal and adulticidal effects of some Egyptian oils against Culex pipiens

Mosquitoes and mosquito-borne diseases represent an increasing global challenge. Plant extract and/or oils could serve as alternatives to synthetic insecticides. The larvicidal effects of 32 oils (1000 ppm) were screened against the early 4th larvae of Culex pipiens and the best oils were evaluated against adults and analyzed by gas chromatography-mass spectrometry (GC mass) and HPLC. All oils had larvicidal activity (60.0-100%, 48 h Post-treatment, and their Lethal time 50 (LT₅₀) values ranged from 9.67 (Thymus vulgaris) to 37.64 h (Sesamum indicum). Oils were classified as a highly effective group (95-100% mortalities), including Allium sativum, Anethum graveolens, Camellia sinensis, Foeniculum vulgare, Nigella sativa, Salvia officinalis, T. vulgaris, and Viola odorata. The moderately effective group (81-92% mortalities) included Boswellia serrata, Cuminum cyminum, Curcuma aromatic, Allium sativum, Melaleuca alternifolia, Piper nigrum, and Simmondsia chinensis. The least effective ones were C. sativus and S. indicum. Viola odorata, Anethum graveolens, T. vulgaris, and N. sativa provide 100% adult mortalities PT with 10, 25, 20, and 25%. The mortality percentages of the adults subjected to 10% of oils (H group) were 48.89%, 88.39%, 63.94%, 51.54%, 92.96%, 44.44%, 72.22%, and 100% for A. sativum, An. graveolens, C. sinensis, F. vulgare, N. sativa, S. officinalis, T. vulgaris, and V. odorata, respectively. Camellia sinensis and F. vulgare were the most potent larvicides whereas V. odorata, T. vulgaris, An. graveolens and N. sativa were the best adulticides and they could be used for integrated mosquito control.

Bovine Leukaemia Virus: Current Epidemiological Circumstance and Future Prospective

Bovine leukaemia virus (BLV) is a deltaretrovirus that is closely related to human T-cell leukaemia virus types 1 and 2 (HTLV-1 and -2). It causes enzootic bovine leukosis (EBL), which is the most important neoplastic disease in cattle. Most BLV-infected cattle are asymptomatic, which potentiates extremely high shedding rates of the virus in many cattle populations. Approximately 30% of them show persistent lymphocytosis that has various clinical outcomes; only a small proportion of animals (less than 5%) exhibit signs of EBL. BLV causes major economic losses in the cattle industry, especially in dairy farms. Direct costs are due to a decrease in animal productivity and in cow longevity; indirect costs are caused by restrictions that are placed on the import of animals and animal products from infected areas. Most European regions have implemented an efficient eradication programme, yet BLV prevalence remains high worldwide. Control of the disease is not feasible because there is no effective vaccine against it. Therefore, detection and early diagnosis of the disease are essential in order to diminish its spreading and the economic losses it causes. This review comprises an overview of bovine leukosis, which highlights the epidemiology of the disease, diagnostic tests that are used and effective control strategies.

West Nile virus seroprevalence and associated risk factors among horses in Egypt

Determination of the seroprevalence and risk factors that are associated with West Nile virus (WNV) in horses is essential for adoption of effective prevention strategies. Our objective in this study, therefore, was to determine the seroprevalence and to identify the risk factors associated with WNV infection in the most densely horse-populated governorates in Egypt. A cross-sectional study was conducted in 2018 on 930 horses, which were distributed over five governorates in the Nile delta of Egypt. The horses, which were randomly selected, were serologically tested through use of an ID screen West Nile competition enzyme-linked immunosorbent assay (ELISA) to detect anti-WNV immunoglobulin G (IgG) and plaque reduction neutralization tests (PRNT; gold standard) to confirm the seropositive status of animals and to avoid cross reaction with other flavi-viruses. Four variables (geographical location, breed, sex and age) were considered in the risk analysis. Univariable and stepwise forward multivariable logistic regression methods were used for risk-factor analysis. The odds ratio (OR) was used as an approximate measure of relative risk. A total of 156 (16.8%; 95% confidence interval (CI) 14.4-19.2; P < 0.001) serum samples were found to be serologically positive for WNV. The highest seroprevalence rate was detected in horses of age ≥ 15 years (68.1%; 95% CI 49.8-72.4), stallions (26.4%; 95% CI 22.7-30.4), and those of mixed breed (21.5%; 95% CI 17.7-27.5). Horses older than 15 years were found to be at increased risk of WNV infection with OR = 4.3 (95% CI 3.0-6.2, P < 0.001) compared with horses aged under 2.5 years. Also, when all the risk factors were considered, stallions were more likely than mares to be WNV seropositive (OR = 2.4, 95% CI 1.6-3.7, P < 0.001), and of the breeds, mixed-breed (OR = 1.9, 95% CI 1.2-2.8, P = 0.005) and Arabian horses (OR = 1.9, 95% CI 1.2-2.8, P = 0.005) were more likely to be seropositive. Geographical location seemed to have no impact on the seroprevalence of exposure to WNV among these horses. Due to these findings, we strongly recommend intensive surveillance and implementation of effective control and prevention strategies against WNV, especially in stallion, mixed-breed horses with ages ≥ 15 years.

Seroprevalence and Risk Factors Associated with Canine Leishmaniasis in Egypt

BACKGROUND

Canine leishmaniasis (CanL) is caused by Leishmania infantum (L. infantum) that is transmitted by sand fly vectors with dogs acting as the main reservoir.

METHODS

The present study aimed to determine the seroprevalence of CanL in dogs from Egypt and assessed the associated risk factors. The study was conducted from 2019 to 2020 in five governorates situated in Northern Egypt. Serum samples from 450 asymptomatic dogs were serologically examined by use of enzyme-linked immunosorbent assay (ELISA).

RESULTS

Overall, the seroprevalence rate of CanL was 21.3% and the highest rates were observed in Cairo and Giza governorates. The univariable analysis revealed that the seropositivity of CanL was strongly related to the dogs' ages, length of hair, absence of veterinary care or application of insecticides, and the type of floor of their shelters. The risk factors that were found to be associated with CanL in exposed dogs were: age group 2-4 years old (OR = 12, 95% CI: 1.6-92.3); short hair (OR = 2.07, 95% CI: 1.2-3.6); absence of veterinary care (OR = 2.7, 95% CI: 1.3-5.8); no application of insecticides (OR = 3.09, 95% CI: 1.5-6.5) and their residence in a shelter with an earthen floor (OR = 1.42, 95% CI: 0.7-2.9).

CONCLUSIONS

Based on the present results, CanL is present in Egyptian dogs and this increases the possibility of transmission by sand fly to humans with whom they have contact. Consequently, an efficient monitoring programme and effective control measures are important to reduce the risk of infection.

Molecular characterization and phylogenetic analysis of lumpy skin disease in Egypt

Lumpy skin disease (LSD) is an infectious viral disease affecting cattle, cause severe economic losses. In the last few years, the disease is widely distributed in many countries in the Middle East, including Egypt. This study aimed to determine the genetic character of LSDV circulating in some governorates in Egypt and its relation with other LSDVs and vaccine strains in GenBank. A total of 50 skin nodules and 50 blood samples were collected from clinically affected cattle to detect LSDV using PCR targeting the P32 gene. The positive samples were characterized using PCR targeting the GPCR gene. The amplified products of four samples detected in the skin nodule of cattle from Alexandria and Kafr ElSheikh governorates were sequenced, and the phylogenetic tree was constructed. Out of 100 analyzed samples, 70 samples were positive for LSDV by PCR assay. In addition, the sequence alignment of the obtained LSDV strains detected in the Alexandria governorate showed high similarity to the LSDV genome (MN995838). In contrast, LSDV strains from Kafr ElSheikh governorate revealed high similarity and the previous Egyptian strain (MG970343), which was isolated from cattle in Sharkia governorate in 2016. Also, the phylogenetic analysis confirmed that one of the LSDV strain (LC601598) from Alexandria is closely related to the LSDV of Menofia/Egypt/2019 (MN271722), while another one (LC601597) is closely related to vaccine strains of LSDV. Moreover, the LSDV strains from Kafr Elsheikh showed closely related to previous LSDV strains isolated from Menofia (MG970343) and Dakahlia (KP071936) governorates and clustered with other LSDV strains in a distinct cluster. This information is for understanding the epidemiology of LSDV and supporting the establishment of an efficient control program for the disease.

A Scoping Review of West Nile Virus Seroprevalence Studies among African Equids

West Nile virus (WNV) is an emerging and re-emerging zoonotic flavivirus first identified in and endemic to Africa. The virus is transmitted between birds by biting mosquitoes, with equids and humans being incidental hosts. The majority of infected incidental hosts display no or only mild clinical signs, but a fraction develop encephalitis. The aim of this scoping review was to identify and evaluate primary research on the presence of antibodies to WNV among African equids. Three bibliographic databases and the grey literature were searched. Of 283 articles identified, only 16 satisfied all the inclusion criteria. Data were collated on study design and outcomes. The overall seroprevalence reported ranged from 17.4 to 90.3%, with 1998 (35%) of the 5746 horses, donkeys and mules having screened positive for WNV antibodies. Several articles determined that seroprevalence increased significantly with age. Due to co-circulation of other flaviviruses in Africa, in the majority of studies that screened samples by ELISA, positive results were confirmed using a more specific neutralization test. However, only eight studies tested against other flaviviruses, including Potiskum, Uganda S, Wesselsbron and yellow fever virus in one, Japanese encephalitis and Usutu virus (USUV) in one, tick-borne encephalitis and USUV in one and USUV only in three. Equids are regarded as useful sentinel animals for WNV, but variation in study design poses challenges when trying to determine risk factors for, and trends in, WNV seroprevalence.

A recent update about seroprevalence of ovine neosporosis in Northern Egypt and its associated risk factors

Neospora caninum (Family: Sarcocystidae) is an obligate intracellular protozoan. It is one of the most critical abortifacients in ruminants. The seroprevalence of antibodies against N. caninum and its risk factors was investigated among 430 sheep from four North Egyptian governorates, Alexandria, Gharbia, Menofia, and Qalyubia, during the period from 2017 to 2018. Generally, the overall prevalence rate of N. caninum among sheep was 8.6%. The logistic regression analysis for the obtained data revealed that N. caninum increased significantly with age (OR = 2.4, 95% CI: 8.4-18.7) of the ewe (OR = 3.3, 95% CI: 7.6-14.9), particularly among sheep in contact with dogs (OR = 4.9, 95% CI: 7.5-14.3). Besides, locality, season, and pregnancy status of examined sheep had no significant effect on the appearance of N. caninum infection. the present findings confirm the presence of N. caninum among sheep in Egypt which probably play a role in reproductive failure in sheep. Therefore, sanitary measures and monitoring of the infection should be implemented to reduce the spreading of the infection.

Seroprevalence and risk factors for lumpy skin disease in cattle in Northern Egypt

Lumpy skin disease (LSD) is an endemic infectious viral disease of cattle in African and Middle East countries. A cross-sectional study was conducted to determine the seroprevalence of LSD among cattle in Northern Egypt and assessed the associated risk factors with LSD infection. A total of 1000 sera samples were collected from cattle and examined serologically with commercial ELISA kit. Overall, the true seroprevalence of LSD among cattle in Egypt was 19.5% (n = 180). The true seroprevalence rate was varied significantly between different geographical studied areas, and the highest level was observed in Kafr El-Sheikh (26.7%) and Gharbia (23.7%) governorates. Moreover, the risk of getting LSD infection was increased among Holstein breed (OR = 4.586; 95%CI, 1.83-11.48) and adult cattle (OR = 2.498; 95%CI, 1.17-5.32) during summer season (OR = 7.303, 95%CI: 3.97-13.42). Furthermore, communal grazing (OR = 1.546; 95%CI, 0.91-2.60), communal water points (OR = 3.283; 95%CI, 2.11-5.09), introduction of new animal (OR = 2.216; 95%CI, 1.32-3.71), and contact with other animals (OR = 3.401; 95%CI, 1.62-7.10) were identified as significant risk factors for the occurrence of LSDV infection in cattle. Moreover, the present study revealed that no significant (P > 0.05) association between sex or type of herd and occurrence of LSD infection.

Seroprevalence, Risk Factors and Molecular Identification of Bovine Leukemia Virus in Egyptian Cattle

Simple Summary

Bovine leukemia virus (BLV) is distributed worldwide and affects dairy cattle causing significant economic losses. This study’s objective was to assess the risk factors associated with BLV infection and identify the Egyptian BLV strain’s genetic diversity. The overall seroprevalence of BLV infection in Egyptian dairy cattle was 18.2%, and the grazing cattle in the losing house system had a higher probability of getting BLV infection. The sequencing and phylogenetic analysis for one Egyptian BLV strain was performed, and the obtained results confirmed the clustering of Egyptian BLV strain into genotype-1.

Abstract

Bovine leukemia virus (BLV) is distributed worldwide and affects dairy cattle causing severe economic losses. The BLV has been serologically reported in Egypt, but few studies have evaluated its associated risk factors and genetic classification. Therefore, this study assessed risk factors associated with BLV infection and identified the genetic diversity of the Egyptian strain. The study was conducted on 500 dairy cattle distributed in four Governorates located in Northern Egypt. Overall, the seroprevalence of BLV infection among Egyptian dairy cattle was 18.2%. The grazing cattle in the losing house system had higher odds for BLV seropositivity, and bad practice such as the use of a single needle or one plastic glove for more than one animal was considered a significant risk factor for BLV infection. Besides, the sequencing and phylogenetic analysis for one Egyptian BLV strain was performed, and the obtained results confirmed the clustering of Egyptian BLV strain into genotype-1. The assessment of associated risk factors for BLV infection and determination of its genetic classification are essential to implement an effective control program.

Risk factor analysis of bovine leukemia virus infection in dairy cattle in Egypt

Identification of the risk factors associated with Enzootic bovine leukosis (EBL) is essential for the adoption of potentially prevention strategies. Accordingly, our objectives were to determine the geographic distribution of Bovine Leukemia Virus (BLV) infection and identify the risk factors associated with cow-level BLV infection in the Egyptian dairy cattle. A cross-sectional study was conducted on 1299 mixed breed cows distributed over four provinces in the Nile Delta of Egypt in 2018. The randomly selected cows on each farm were serologically tested for BLV, and the cow's information was obtained from the farm records. Four variables (geographic location, herd size, number of parities, and age) were used for risk analysis. A total of 230 serum samples (17.7 %) were serologically positive for BLV. The highest prevalence of BLV infection was associated with parity (OR = 3.4, 95 %CI 2.4-4.9) with 80 % probability of being BLV-positive at parity ≥5, followed by herd size (OR = 1.8, 95 %CI 1.4-2.2). However, geographic location seems to have no impact on the prevalence of BLV infection in Egypt. Our findings strongly indicate that the intensive surveillance and effective prevention strategies against BLV infection in Egypt should be provided to multiparous cows with ≥5 parities and live in large farm with more than 200 cows.

The first detection of anti-West Nile virus antibody in domestic ruminants in Egypt

West Nile virus (WNV) is a mosquito-borne disease, usually present as a symptomatic disease but can cause various clinical signs ranged from mild fever to severe encephalitis and death in various animals and humans. In Egypt, the epidemiological data about WNV infection in different animal species particularly in domestic ruminants are scarce. The present study aimed to investigate the seroprevalence of WNV in cattle, buffalo, camel, sheep, and goats at some Governorates northern Egypt. In total, 360 serum samples (100 cattle, 50 buffalo, 50 camels, 85 sheep, and 75 goats) were examined using ELISA. The results revealed that the seroprevalence of WNV among ruminants was highly significant (P = 0.03) at Kafr El Sheikh Governorate (17.6%) in comparison with other the Governorates. Besides, the seroprevalence of WNV antibodies significantly differed between the examined species (P = 0.0001); it was 22%, 0%, 40%, 3.5%, and 5.3% in cattle, buffalo, camel, sheep, and goats, respectively. This is the first study to confirm that domestic ruminants act as a reservoir in the epidemiology of WNV infection and represent a risk for human and equine infections in Egypt.