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

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdelfattah Selim ◽  
Ameer Megahed ◽  
Sahar Kandeel ◽  
Abdulaziz Alouffi ◽  
Mashal M. Almutairi

AbstractDetermination 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.

2020 ◽  
Author(s):  
Abdelfattah selim ◽  
Ameer Megahed ◽  
Sahar Kandeel ◽  
Abdullah Alanazi

Abstract Determination of the seroprevalence and risk factors associated with West Nile Fever (WNF) in horses is essential for adoption of effective prevention strategies. Our objective was therefore to determine the seroprevalence and identify the risk factors associated with West Nile virus (WNV) infection in the most densely horse populated provinces in Egypt. A cross-sectional study was conducted on 930 horses distributed over five provinces in the Nile Delta of Egypt in 2018. The randomly selected horses from geographical studied areas were serologically tested for WNF, and the horses’ information was obtained from owners. Four variables (geographic location, breed, gender, and age) were used for risk analysis. A total of 156 (16.8%) serum samples were serologically positive for WNV. The highest prevalence of WNV infection was between mixed breed (21.5%), male (26.4%) horses with age ≥ 15 years (68.1%). Age showed the highest risk for the infection with WNV (OR = 4.3, 95% CI 3.0 to 6.2). Gender and breed also showed important risk factors for WNF infection in horses (OR = 2.4, 95% CI 1.6 to 3.7; OR = 1.9, 95% CI 1.2 to 2.8, respectively). However, geographic location seems to have no impact on the seroprevalence of WNV infection among horses in the Nile Delta of Egypt. Our findings strongly recommend intensive surveillance and implementation of effective control and prevention strategies against WNF especially in male of mixed breed horses with ages ≥ 15 years.


2021 ◽  
Vol 8 (10) ◽  
pp. 236
Author(s):  
Abdelfattah Selim ◽  
Salma Shoulah ◽  
Abdelhamed Abdelhady ◽  
Abdulaziz Alouffi ◽  
Yasser Alraey ◽  
...  

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.


2021 ◽  
pp. 1241-1245
Author(s):  
Ibrahim Alzuheir ◽  
Adnan Fayyad ◽  
Nasr Jalboush ◽  
Rosemary Abdallah ◽  
Sameeh Abutarbush ◽  
...  

Background and Aim: West Nile fever (WNF) is a neurotropic, mosquito-borne disease affecting humans and domesticated animals, caused by a member of the genus Flavivirus. Over the last decades, this virus has been responsible for several cases of illness in humans and animals. The current epidemiological status of WNF in horses is insufficient, and in veterinarians, as an occupational hazard is unknown. This study aimed to investigate and determine the seroprevalence and risk factors for WNF in veterinarians and horses in Palestine. Materials and Methods: In this study, serum samples from 100 veterinarians and 87 horses were collected between August 2020 and September 2020 from different cities of Northern Palestine. West Nile virus (WNV) antibodies were detected using an enzyme-linked immunosorbent assay. Results: Our results showed that 60.9% of the horse serum samples were positive in all investigated cities. In horses, location is a risk factor for the seropositivity for WNF, whereas age, sex, breed, and intended use of the horses, were not associated with increased WNF seropositivity. In veterinarians, 23.0% of the serum samples were positive. Positive samples were detected in all locations, age groups, experience length, and work sectors. However, the seropositivity for WNF was not influenced by these variables. Conclusion: The results revealed that WNV circulates in most regions of Palestine. Our results will help determine the risk of infection in animals and humans and control WNV transmission. Surveillance studies on humans, vectors, and animals are needed to better define endemic areas.


Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 494
Author(s):  
Angela Petruccelli ◽  
Tiziana Zottola ◽  
Gianmarco Ferrara ◽  
Valentina Iovane ◽  
Cristina Di Russo ◽  
...  

Background: A retrospective sero-survey for evidence of West Nile virus (WNV) infection in European wild boar (Sus scorfa) was conducted in the Latium region, Italy, on stored serum samples of the period November 2011 to January 2012. Methods: Sera were collected from 168 European wild boars and screened for antibodies to WNV and other Flaviviruses by competitive enzyme linked immunosorbent assay (cELISA). All sera positive for Flavivirus antibodies by cELISA were further examined by virus neutralization test (VNT). To test the presence of Flavivirus RNA in samples, an RT-PCR was performed using a pan-Flavivirus primers pair. Results: Thirteen wild boars (7.73%) were seropositive for Flaviviruses. The hemolysis of serum samples limited the interpretation of the VNT for 7 samples, confirming the presence of specific antibody against WNV in a single European wild boar serum sample. The presence of ELISA positive/VNT negative samples suggests the occurrence of non-neutralizing antibodies against WNV or other antigen-related Flaviviruses. No samples resulted positive for Flavivirus by RT-PCR assay. Conclusion: Although a moderately high percentage of animals with specific antibody for WNV has been detected in wild boar in other surveillance studies in Europe, this has not been reported previously in Italy. Together, these data indicate that European wild boar are exposed to WNV and/or other related-Flavivirus in central Italy and confirm the usefulness of wild ungulates, as suitable Flavivirus sentinels.


Author(s):  
Matthew Finn

West Nile virus (WNV) is a single-stranded RNA virus of the Flavivirus family that is transmitted via a mosquito vector, typically causing fever and capable of causing meningoencephalitis. Although mortality is low, it can lead to debilitating neuroinvasive disease in some patients. WNV is a leading cause of domestically-acquired arboviral disease and most commonly occurs in late August and early September. Consider WNV in otherwise unexplained cases of meningitis or encephalitis. Initial testing should consist of cerebrospinal fluid (CSF) analysis and West Nile immunoglobulin M enzyme-linked immunosorbent assay in serum and/or CSF. WNV is a nationally notifiable disease. Prevention remains the key to controlling this disease. Reducing the breeding grounds of the Culex mosquito and using insect repellant to prevent bites are two important strategies.


2009 ◽  
Vol 16 (9) ◽  
pp. 1332-1337 ◽  
Author(s):  
Michael M. Lieberman ◽  
Vivek R. Nerurkar ◽  
Haiyan Luo ◽  
Bruce Cropp ◽  
Ricardo Carrion ◽  
...  

ABSTRACT The immunogenicity and protective efficacy of a recombinant subunit West Nile virus (WNV) vaccine was evaluated in rhesus macaques (Macaca mulatta). The vaccine consisted of a recombinant envelope (E) protein truncated at the C-terminal end, resulting in a polypeptide containing 80% of the N-terminal amino acids of the native WNV protein (WN-80E), mixed with an adjuvant (GPI-0100). WN-80E was produced in a Drosophila melanogaster expression system with high yield and purified by immunoaffinity chromatography using a monoclonal antibody specific for flavivirus E proteins. Groups of monkeys were vaccinated with formulations containing 1 or 25 μg of WN-80E antigen, and both humoral and cellular immunity were assessed after vaccination. The results demonstrated potent antibody responses to vaccination, as determined by both enzyme-linked immunosorbent assay and virus-neutralizing antibody assays. All vaccinated animals responded favorably, and there was little difference in response between animals immunized with 1 or 25 μg of WN-80E. Cellular immunity was determined by lymphocyte proliferation and cytokine production assays using peripheral blood mononuclear cells from vaccinated animals stimulated in vitro with WN-80E. Cell-mediated immune responses varied from animal to animal within each group. About half of the animals responded with lymphoproliferation, cytokine production, or both. Again, there was little difference in response between animals immunized with a 1- or 25-μg dose of WN-80E in the vaccine formulations. In a separate experiment, groups of monkeys were immunized with the WN-80E/GPI-0100 vaccine or an adjuvant-only control formulation. Animals were then challenged by inoculation of wild-type WNV, and the level of viremia in each animal was monitored daily for 10 days. The results showed that whereas all animals in the control group had detectable viremia for at least 3 days after challenge, all of the vaccinated animals were negative on all days after challenge. Thus, the WN-80E vaccine was 100% efficacious in protecting monkeys against infection with WNV.


2009 ◽  
Vol 56 (6-7) ◽  
pp. 370-375 ◽  
Author(s):  
K. O. Murray ◽  
E. Koers ◽  
S. Baraniuk ◽  
E. Herrington ◽  
H. Carter ◽  
...  

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