Serological Survey and Associated Risk Factors on Toxoplasma Gondii Infection in Goats in Mila District, Algeria
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DOI: 10.2478/fv-2020-0007 FOLIA VETERINARIA, 64, 1: 48—59, 2020 SEROLOGICAL SURVEY AND ASSOCIATED RISK FACTORS ON TOXOPLASMA GONDII INFECTION IN GOATS IN MILA DISTRICT, ALGERIA Dahmane, A.1, 2, Boussena, S.3, Hafsi, F.1, 4, Ghalmi, F.1, 4 1Higher National Veterinary School of Algiers. Oued Smar, Bab Ezzouar 2Exploration and Valorization of Steppe Ecosystems Laboratory Faculty of Nature and Life Sciences, Ziane Achour University, Djelf 3Management of Animal Health and Productions Laboratory Institute of Veterinary Sciences, University of Constantine 1, Constantine 4Management of Local Animal Resources Laboratory Higher National Veterinary School of Algiers. Oued Smar, Bab Ezzouar, Algeria [email protected] ABSTRACT sis of some factors thought to be related to the onset of this infection such as age, sex, management system, Toxoplasma gondii is a protozoan parasite prevalent locality and presence of cats showed no significant rela- in humans and other animals worldwide having medical tionship (P > 0.05); these factors did not seem to affect and veterinary importance on account of reproductive the frequency of the infection. The seropositivity level failure causing significant socioeconomic losses. The of T. gondii was significantly higher in aborted goats aims of this study were to estimate the seroprevalence (P = 0.007), which suggested that they may play a sig- of T. gondii infection in goats, determined the possible nificant role in pregnancy failure. In the concordance risk factors associated, and evaluate the performances of evaluation between the two serological tests (ELISA and the latex agglutination test (LAT) to anti-T. gondii anti- LAT), the Cohen’s Kappa value was calculated and the bodies screening using the indirect Enzyme-linked im- results showed a K of 0.519 (p = 0.000) belonging to the munosorbent assay as a reference test (iELISA). A total range of 0.41—0.60 indicating just average agreement. of 184 serum samples from goats reared on 25 farms in The results of the Mc Nemar test showed that both tests Mila district from North-Eastern Algeria were collected gave significantly different results and seropositivity and tested for anti-T. gondii IgG antibodies using two values (P < 0.05). Thehigh prevalence observed in this commercial serological tests (ELISA and LAT). A se- study indicated a widespread exposure to T. gondii from roprevalence rate of 71.73 % and 63.58 % was obtained goats and the potential risk of T. gondii infection for hu- by both ELISA and LAT tests, respectively. The analy- mans in North-Eastern Algeria. These results elucidate 4848 the challenges of applying serology to estimate goat ex- MATERIALS AND METHODS posure to T. gondii. The choice between the two serologi- cal tests will depend on their performances, as well as Study area and the environment the availability of the equipment, laboratory conditions This study was carried out in the province of Mila, in and the number of samples to be tested. North-Eastern Algeria, from January to April 2017. Mila lies inland about 82 km from the Mediterranean coast. The Key words: Algeria; ELISA; goat; LAT; performanc- wilayate (district) is characterized by a varied relief and es; risk factors; Toxoplasma gondii presents two large distinct zones; to the north, mountains, and hills: M’sid, Aicha, Zouagha and El-Halfa, and to the south, the plains and highlands with an area of 3481 km2. INTRODUCTION Our study was conducted in two municipalities in the North of this wilayate; the municipality of Terrai Bainen Toxoplasmosis is a cosmopolitan zoonotic disease and that of Zeghaia. The elevation was 185 to 1190 m. The caused by a protozoan parasite, Toxoplasma gondii. It is north of this region was home to three large cork oak for- of economic importance for both veterinary and human ests, to the west, there was a large forest of exploitation, and medicine [34]. The infection of sheep and goats causes sig- between the two towns is the Beni-Haroun Dam; the larg- nificant losses in reproduction, but also has a major impact est water dam at the national level which supplies a large on public health, as the consumption of infected products part of Eastern Algeria with drinking and irrigation water. such as undercooked meat and unpasteurized milk facili- The region has a Mediterranean climate with hot, dry tates its zoonotic transmission [11]. Fetal mortality rates summers and cold, wet winters. The climate is humid in including goat abortion in the affected flocks can reach 50 the North, subhumid to semi-arid in the center and semi- % and in subclinical cases, losses are low [55]. arid in the South. The rainfall varies between 600 and 900 Goats are economically important animals in many mm in the North of the wilayate (920 mm on the mount of countries and constitute one of the main sources of meat Msid Aicha), between 400 and 600 in the centre and less and milk for Islamic populations and villagers [53]. For ex- than 400 mm in the South. In the summer, the temperature ample, villagers’ consumption of unpasteurized goat milk varies between 25 and 40 °C and the average winter tem- due to their cultural traditions and dietary habits is an im- peratures range from 0 to 12 °C [60]. portant source of T. gondii infection [40]. Seroprevalence The breeding season usually starts in July, when day- studies have been conducted on different animal species light begins to decline. The rearing mode is usually semi- in different parts of the world [11, 38]. There are very few intensive or extensive. All herds included in this study reports on the prevalence of toxoplasmosis in goats in dif- grazed during the spring season until the end of Decem- ferent parts of Algeria. ber with variations depending on the climatic conditions; The importance of T. gondii disease for public health these goats feed almost exclusively outside the barn with- and the lack of epidemiological data in humans and do- out supplementation. In the winter, goats were housed and mestic animals in Algeria led us to conduct this cross-sec- fed with straw, barley, and wheat bran. The association tional study on goat farms. This study allows us to estimate between goat and sheep farming is very common in this the prevalence of this infection and to know the main risk region. factors associated. Also, the evaluation of serological tests becomes im- Study plan and the target population portant in order to ascertain the most sensitive and specific A cross-sectional study was conducted. According to tests in epidemiological studies to use in different animal the data from the Algerian Ministry of Agriculture, there species [51, 72]. In this regard, the objective was also to were 8652 herds and about 34 000 goat heads at Mila dur- evaluate the performance of two serological tests (ELISA ing the study period. An appropriate number of goats aged and LAT) in the detection of anti-T. gondii antibodies in 4 to 96 months were sampled by a simple random sampling goats. method. Also, the number of goats to be taken from each farm 49 was defined based on the total number of animals. The im- able data on herd size, sex, age, breed, history of abortion, portant thing was to have a representative sample of at least presence of cats and management system had been col- 10 % of all individuals in each farm visited. lected previously. The farms sampled consisted mainly of The required sample size was calculated according to goats of local breeds (100 %). The sample (184 goats tested the following formula with an expected prevalence of 10 % serologically) included 129 females (70.10 %) and 55 males and a 95 % confidence interval [70]: (29.89 %). The animals were divided into three age groups: ≤ 12 months (24.45 %), 12 to 36 months (29.34 %) and N = [Z2 × P(1 – P)]/d2 more than 36 months (46.19 %). Of the females selected, 73 (56.58 %) had a history of abortion. Where; N is the number of samples to be collected in the study, Collection of the blood samples Z is the value of the normal distribution for the confi- The blood (5 ml) was drawn from the jugular vein of dence interval of 95 % [Z2 = (1.96)2], selected goats using disposable needles and plain vacutain- P is the expected prevalence, er tubes and transported to the laboratory on ice. Serum d is the absolute error of 10 %. samples were harvested by centrifugation at 2,000 × g for 10 min, then stored in labeled Eppendorf tubes at −20 °C A minimum of 100 samples was required. To increase until testing. the power of the statistical analysis, the sample size was multiplied by 2. Twenty-five herds were randomly selected Laboratory analysis and the herd sizes ranged from 5 to 120 heads. The detection of anti-T. gondii antibodies was conduct- At the individual level, the sample size was determined ed in the Microbiology Laboratory of the National Veteri- for each flock to detect the existence of the disease. The nary School of Algiers (ENSV). After the thawing of the calculations were performed according to the formula sera at room temperature, it proceeded to the serological commonly used in veterinary epidemiological surveys by analyzes of the 184 sera using two commercial serological T h r u s f i e l d [72]: kits: the ELISA ID Screen® Toxoplasmosis Indirect Multi- species (IDvet, Grabels, France) and the LAT Toxo-Latex® n = [1 – (1š – p)1/d] × [N – (d/2)] + 1 (SPINRER EACT, S. A. Ctra Santa Coloma, Spain) accord- ing to the manufacturer’s protocol. Where: n is the size of the sample in each flock, ELISA (Enzyme Linked Immunosorbent Assay) p is the detection probability of least one seropositive The IgG antibodies against T.