Mohamed Abdelsalam Abdalla

Prevalence of bluetongue virus infection and associated risk factors among cattle in North Kordufan State, Western Sudan

BackgroundBluetongue virus causes febrile disease in sheep and a fatal hemorrhagic infection in North American White-tailed deer. However, in cattle the disease is typically asymptomatic and no clinical overt disease is associated with bluetongue infection. Bluetongue virus activity has been detected in Khartoum, Sennar and South Darfur states of the Sudan. Currently, no information is available in regard to previous exposure of livestock to Bluetongue virus in North Kordufan State, the largest livestock producing region in the country. The present study was conducted to determine the prevalence of bluetongue antibodies and to identify the potential risk factors associated with the presence of bluetongue antibodies among cattle in North Kordufan State, Sudan. A total of 299 bovine blood samples were collected randomly from six localities in North Kordufan State and were tested by enzyme-linked immunosorbent assay (ELISA) for detection of BTV-specific immunoglobulin G (IgG) antibodies.ResultsThe serological evidence of Bluetongue virus infection was observed in 58 out of 299 cows, accounting for a 19.4% prevalence rate among cattle in North Kordufan State. Older cattle (>2 years of age) had four times the odds to be infected with BTV compared to young cattle (OR = 4.309, CI = 1.941-9.567, p-value = 0.01). Application of preventive measures, such as spraying or dipping with insecticide protects cattle against Bluetongue infection. Application of vector control measures decreased the odds for bluetongue seropositivity by 7 times (OR = 7.408, CI = 3.111-17.637, p-value = 0.01).ConclusionsThe results of this study indicated that age and application of routine insecticides are influential risk factors for seroprevalence of Bluetongue in cattle. Surveillance of Bluetongue virus should be extended to include other susceptible animals and to study the distribution of the insect vectors in the region to better predict and respond to BTV outbreak in the State of North Kordufan, Sudan.

A single-tube RT-PCR for rapid detection and differentiation of some African isolates of palyam serogroup orbiviruses

A single-tube nested reverse transcriptase (nRT) polymerase chain reaction (nRT-PCR) was developed and evaluated for detection of palyam serogroup orbiviruses ribonucleic acid (RNA) in cell cultures and clinical samples. A pair of outer primers (pal1 and pal2), designed from genome segment three of Chuzan virus of the palyam viruses serogroup, resulted in amplification of a primary 660-base pair (bp) PCR product. Using a pair of internal (nested) primers (pal3 and pal4), the nRT-PCR produced a 350-bp PCR product. The primary and the nested PCR products were amplified from RNA extracted from Sudanese and South African isolates of palyam viruses, propagated in cell cultures. Application of this nRT-PCR to clinical samples resulted in direct detection of palyam virus RNA in blood and serum samples from infected cattle and goats. The nested amplification increased the sensitivity of the assay by 1000-fold, and specific PCR products were detected from as little as 0.1fg of viral RNA. Amplification products were not detected when the nRT-PCR was applied to RNA from closely related orbiviruses including, bluetongue virus (BTV) serotypes 1, 2, 4, 6; epizootic hemorrhagic disease of deer virus prototype serotype 1 (EHDV-1); Sudanese isolates of EHDV-318; total nucleic acid extracts from non-infected Vero cells; and blood and sera from goats and calves from which virus was not isolated. This nRT-PCR provides a reliable, sensitive and specific assay for rapid detection and differentiation of palyam viruses from other related orbiviruses. In addition, the assay is recommended for inclusion in epidemiological surveys and during investigation of an epizootic of the disease among susceptible ruminants.

Smear Microscopy for Diagnosis of Pulmonary Tuberculosis in Eastern Sudan

Background In Sudan, tuberculosis diagnosis largely relies on clinical symptoms and smear microscopy as in many other low- and middle-income countries. The aim of this study was to investigate the positive predictive value of a positive sputum smear in patients investigated for pulmonary tuberculosis in Eastern Sudan. Methods Two sputum samples from patients presenting with symptoms suggestive of tuberculosis were investigated using direct Ziehl-Neelsen (ZN) staining and light microscopy between June to October 2014 and January to July 2016. If one of the samples was smear positive, both samples were pooled, stored at −20°C, and sent to the National Reference Laboratory (NRL), Germany. Following decontamination, samples underwent repeat microscopy and culture. Culture negative/contaminated samples were investigated using polymerase chain reaction (PCR). Results A total of 383 samples were investigated. Repeat microscopy categorized 123 (32.1%) as negative, among which 31 were culture positive. This increased to 80 when PCR and culture results were considered together. A total of 196 samples were culture positive, of which 171 (87.3%), 14 (7.1%), and 11 (5.6%) were M. tuberculosis, M. intracellulare, and mixed species. Overall, 15.6% (57/365) of the samples had no evidence of M. tuberculosis, resulting in a positive predictive value of 84.4%. Conclusions There was a discordance between the results of smear microscopy performed at local laboratories in the Sudan and at the NRL, Germany; besides, a considerable number of samples had no evidence of M. tuberculosis. Improved quality control for smear microscopy and more specific diagnostics are crucial to avoid possible overtreatment.

Infections mycobactériennes dans les carcasses de ruminants abattus dans les deux abattoirs de Kassala au Soudan

Tuberculosis (TB) is a chronic infectious disease of both humans and animals. It is characterized by progressive development of granulomatous lesions in affected tissues and organs (Shitaye et al., 2006; Theon et al., 2006). TB is caused by slow growing non-pigmented bacilli that belong to the Mycobacterium tuberculosis complex (MTBC). Mycobacterium bovis, M. caprae, and M. tuberculosis are responsible for causing TB in cattle, goats, and humans respectively and occasionally in other animal species (Malone et al., 2003; Smith et al., 2006; Radostits et al., 2007; Marianelli et al., 2010; Mamo et al., 2011). Moreover, different species of non-tuberculous mycobacteria are able to cause infections in different species of animals (Radostits et al., 2007; Asil et al., 2013; Aljameel et al., 2014). ■ S A N TÉ A N IM A LE E T ÉP ID ÉM IO LO G IE

Food Safety Knowledge among Food Workers in Restaurants of Salalah Municipality in Sultanate of Oman

This survey was conducted from June to December 2012 in Salalah Municipality, Sultanate of Oman, to investigate the knowledge of restaurants workers about food safety-related issues. A total of questionnaireguided interviews with 21restaurant workers and food handlers were carried out. Major food safety knowledge concepts including personal hygiene, prevention of cross contamination, general sanitation, safe storage of food, knowledge of health problems that would affect food safety, knowledge of symptoms of foodborne illnesses, and knowledge of important foodborne pathogens were investigated. The responses of interviewed workers varied considerably. In general, the workers had good knowledge about some food safety-related issues and not enough knowledge about other issues. Although the results of the questionnaire showed that the majorityof the food workers and handlers know the importance of washing hands before work and proper cleaning and handing of instruments and kitchen utensils and their role in reducing the risk of food contamination, in addition to their knowledge that eating and drinking at the work place increases the risk of food contamination, its observed that these workers do not practice that as a part of their routine work. Therefore, training programs are warranted together with continuous monitoring of the workers’ behavior and practices. Keywords— Food safety, knowledge, food workers,

Seroprevalence and risk factors of brucellosis in camels in and around Alzulfi, Saudi Arabia

This cross-sectional study was conducted from December 2013 to November 2014 to determine the seroprevalence of brucellosis in camels and to investigate its risk factors in and around Alzulfi, Kingdom of Saudi Arabia. A total of 750 sera were collected from camels from 59 herds and tested using Rose Bengal Plate Test (RBPT) and Compelisa (cELISA). The overall seroprevalences were 6.5% using RBPT and 3.2% using cELISA while the herd-prevalence was 45.8% and the within-herd prevalence ranged from 1.0% to 9.9%. With exception of between-locations, there were no significant statistical variations between the seroprevalence estimated for the different categories of the investigated risk factors. In the univariate analysis, location (χ2=13.65, p=0.001) and watering (χ2=4.830, p=0.028) were statistically associated with RBPT-positivity whereas, location (χ2=4.304, p=0.038), age (χ2=6.306, p=0.043) and awareness (χ2=5.106, p=0.024) were associated with cELISA-positivity. The multivariate analysis showed that camels in Alzulfi (Exp(B)=3.13, p=0.001) and she-camels (Exp(B)=2.38, p=0.038) were related to RBPT-positivity and camels in Alzulfi (Exp(B)=5.76, p=0.001), the age-group 6–10 years old (Exp(B)=6.55, p=0.016) and semi-intensive husbandry (Exp(B)=5.80, p=0.009) were associated with cELISA-positivity. A substantial agreement between the 2 tests was shown by Kappa analysis. In conclusion, the seroprevalence reported in this study was not similar in and around Alzulfi. A wide-area multi-animal species survey of brucellosis is warranted in Saudi Arabia.

Histomorphometric parameters of normal full term placenta of Sudanese women

The aim of the study was to provide values for morphometric parameters of histological components of normally delivered full term placentas of Sudanese women and compare them with reported parameters for other ethnic groups. A total of 200 histological sections, stained with hematoxylin and eosin and trichrome stains were used to give a final sample of 1000 fields saved as PowerPoint images for histomorphometry. A systematic random sampling procedure was adopted to ensure the optimum sample size that keeps the percentage error below 5% for the volume estimates. Standard stereological methods of point-counting and intersection-counting were applied to the microscopic fields to determine the volumes of placental components and surface area of fetal-maternal interface. The morphometric parameters showed no variations either between the placentas or between central and peripheral regions. The placental villi and the intervillus space occupied 65% and 35% of placental volume respectively with mean absolute values of 318 cm3 and 169 cm3. The mean absolute volume of the intervillus space was less than that of other ethnic groups by 8.67% but was significantly larger than that of the fetal capillaries which measured 41.2 cm3. The ratio of the absolute volume of the intervillus space to the volume of the fetal blood capillaries was 4:1 in both Sudanese and other ethnic groups. In the placental villi the fetal connective tissue together with the contained blood vessels larger than capillaries occupied 88% of the villus volume. The mean surface area of the fetal-maternal interface of the placental villi (syncytiotrophoblast) was 12.59 M2.