Seroepidemiological survey of contagious bovine pleuropneumonia among cattle in El Jazeera State (Central Sudan).

BACKGROUND: Contagious bovine pleuropneumonia (CBPP) is an economically important infectious disease that is characterized by a variable course and insidious nature. A cross-sectional study was conducted in El Jazeera State, Central Sudan, to determine the seroprevalence and risk factors of CBPP in cattle from seven localities. A total of 218 serum samples were randomly collected from apparently healthy cattle aged older than 6 months between April and May 2021 and were tested serologically using a commercial ELISA kit. RESULTS: The overall seroprevalence of CBPP was 50.5% (110/218). Univariate analysis showed a significant difference (p < 0.05) between sex, locality and water source and seropositivity to CBPP. Multivariate analysis revealed that the independent risk factors (sex, locality and water source) were also statistically significant (p < 0.05). At herd level, out of 20 herds 16 (80%) proved to be positive for CBPP antibodies. It is apparent from the present study that CBPP infection is prevalent among cattle in El Jazeera State, Central Sudan. CONCLUSIONS: To the best of our knowledge, this is the first seroepidemiological study on CBPP infection in Central Sudan. The authors recommend major awareness both in the production area and quarantine centers, as CBPP may result in restrictions on the international trade of animals and animal products.

Serological, virological and molecular diagnosis of an outbreak of lumpy skin disease among cattle in Butana area, Eastern Sudan.

BACKGROUND: Lumpy skin disease (LSD) is a highly infectious disease of cattle caused by a virus of the Poxviridae family, genus Capripoxvirus. The disease has great economic effects on the global cattle industry. In this study, an outbreak of LSD among cattle which occurred in Nahr Atbara and Halfa El Jadida locations in Butana area, Kassala State in November, 2020 is described. METHODS: Lumpy skin disease virus (LSDV) antibody and nucleic acid were detected in specimens (n = 50) using enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). RESULTS: The virus was isolated on the chorioallantoic membrane (CAM) of embryonated chicken eggs and identified by PCR. The number of animals at risk was 295 with a morbidity rate of 4.1% and a mortality rate of 2.4%. CONCLUSIONS: LSDV was diagnosed for the first time in the Butana region, Kassala State, Eastern Sudan in 2020.

Prevalence of Antibodies to Simbu Serogroup Viruses in Cattle in Sudan.

The Simbu serogroup is one of the serogroups that belong to the Orthobunyavirus genus of the family Peribunyaviridae. Simbu serogroup viruses are transmitted mainly by Culicoides biting midges. Meager information is available on Simbu serogroup virus infection in ruminants in Sudan. Therefore, in this study, serological surveillance of Simbu serogroup viruses in cattle in seven states in Sudan was conducted during the period from May, 2015, to March, 2016, to shed some light on the prevalence of this group of viruses in our country. Using a cross-sectional design, 184 cattle sera were collected and tested by a commercial SBV ELISA kit which enables the detection of antibodies against various Simbu serogroup viruses. The results showed an overall 86.4% prevalence of antibodies to Simbu serogroup viruses in cattle in Sudan. Univariate analysis showed a significant association (p=0.007) between ELISA seropositivity and states where samples were collected. This study suggests that Simbu serogroup virus infection is present in cattle in Sudan. Further epizootiological investigations on Simbu serogroup viruses infection and virus species involved are warranted.

First report on molecular characterization and phylogenetic analysis of Reticuloendotheliosis virus in Sudan.

The reticuloendotheliosis virus (REV) group of retroviruses infects a wide range of avian species, including chickens, turkeys, ducks, geese, quail, and prairie chickens. The infection can result in immunosuppression, runting syndrome, high mortality, acute reticular cell neoplasia, or T- and/or B-cell lymphoma. One PCR positive chicken spleen sample obtained in a previous study in addition to one Marek's disease and three fowl pox (FP) vaccine samples were investigated in this study. A PCR assay was performed to detect the presence of REV provirus DNA in these samples. The results indicated the contamination of fowl pox virus and Marek's disease vaccines with REV. In addition, detection of integration of REV inside the genome of fowl pox vaccine was confirmed using primers corresponding to the FPV DNA regions flanking the REV integration site. Alignments of two sequences, one from the spleen tissue and the other from contaminated FP vaccine with REV, with other REV (env) gene sequences obtained from GenBank indicated their high similarity. Furthermore, phylogenetic analysis indicated that the partial part of (env) gene of our two isolates was closely related to variants from India, USA, Taiwan, and China. These results confirmed the contamination of commercial fowl pox and Marek's disease vaccines used in Sudan with REV. Phylogenetic analysis indicated that the partial part of (env) gene sequences from Sudan was closely related to variants from India, USA, Taiwan, and China.

Serological and molecular identification of Reticuloendotheliosis virus (REV) in chickens in Sudan.

BACKGROUND: Reticuloendotheliosis virus (REV) is a gammaretrovirus that belongs to the family of Retroviridae. The infection can result in immunosuppression, runting syndrome, high mortality, acute reticular cell neoplasia or T- and/ or B-cell lymphoma, in a variety of domestic and wild birds. The disease is widespread around the world. No related data have been reported in Sudan about the disease. The present study was conducted to determine the prevalence of REV antibodies and DNA in local and commercial breeds of chickens older than 20 weeks from June 2014 to February, 2017. METHODS: A total of 460 sera samples and 150 (50 liver and 100 spleen) tissue samples were collected from local and commercial breeds of chickens older than 20 weeks and screened for anti-REV antibodies in four states of Sudan using a commercial REV antibody ELISA test kit (IDEXX). Polymerase chain reaction (PCR) was performed to detect REV DNA in tissue samples in Khartoum State. RESULTS: The results revealed that the overall seroprevalence of REV was 74.6% among local and commercial chicken breeds, but in commercial it was 79.5% (190/239) and 69.2% in local breeds (153/221). One hundred and fifty tissue samples of chickens (50 liver, 100 spleen) were tested using PCR for detection of REV using primer sets of the conserved region in envelope glycoprotein (env) gene with a band length of 850 bp. Five out of 50 (10%) liver samples were RE provirus DNA positive detected by PCR, whereas 15 out of 100 (15%) spleen samples were PCR positive. Univariate analysis revealed there was a difference (p ≤ 0.05) between locality and breed of chickens and seropositivity to REV. CONCLUSIONS: The prevalence of the disease was high in Sudan and more studies are needed to evaluate the epidemiology and pathogenesis of the virus.