First isolation and genotyping of Toxoplasma gondii strains from domestic animals in Tunisia.

The isolation and molecular typing of Toxoplasma gondii strains provide an essential basis for a better understanding of the parasite's genetic diversity, determinants of its geographical distribution and associated risks to human health. In this study, we isolated and genetically characterized T. gondii strains from domestic animals in Southern and coastal area of Tunisia. Blood, hearts and/or brains were collected from 766 domestic animals (630 sheep and 136 free-range chickens). Strain isolation from these samples was performed using mouse bioassay and genotyping was carried out with a multiplex PCR technique using 15 microsatellite markers. Thirty viable strains of T. gondii were successfully isolated from tissues of sheep (19/142) and chickens (11/33). In addition, 3 strains could be successfully genotyped from animal tissues for which mouse bioassay was unsuccessful. A large predominance of type II strains (n = 29) was found in the sampled regions, followed by type III (n = 3) and, for the first time in Tunisia, a single isolate of Africa 4 lineage from a sheep. Analyses of population genetics showed the presence of a divergent population of type II lineage in Tunisia, supporting limited recent migrations of strains between Tunisia and other countries of the world.

Seroprevalence of Toxoplasma gondii among healthy blood donors in two locations in Tunisia and associated risk factors.

Toxoplasma gondii is a protozoan parasite that can be transmitted to humans through a variety of routes including blood transfusion. This study aimed to investigate the seroprevalence of T. gondii infection and associated risk factors in healthy blood donors in Tunisia. A total of 800 healthy blood donors from two blood centers in south and coastal Tunisia were analyzed for anti-T. gondii IgG and IgM antibodies by indirect immunofluorescence assay (IFA) and enzyme-linked immunoassays (ELISA), respectively. Structured questionnaires were used to gather information on risk factors for T. gondii infection during collection. The overall seroprevalence was 44.4% of which 352 (44%) and 3 (0.4%) were positive for IgG and both IgG and IgM anti-T. gondii antibodies, respectively. Multivariate analysis showed that T. gondii seropositivity was significantly associated with the birth place (adjusted odds ratio [OR] = 2.72; 95% confidence interval [CI]: 1.49-4.94) and the age of the donors (adjusted OR = 4.98; 95% CI: 1.50-16.58) which are independent risk factors. In addition, the variables of hand washing before eating (adjusted OR = 0.52; 95% CI: 0.37-0.74) and living in an urban environment (adjusted OR = 0.30; 95% CI: 0.13-0.71) are two protective factors. This study provided the first data on the seroprevalence and epidemiology of T. gondii infection in healthy blood donors in Tunisia.

TITLE: Séroprévalence de Toxoplasma gondii chez des donneurs de sang sains dans deux sites en Tunisie et facteurs de risque associés. ABSTRACT: Toxoplasma gondii est un parasite protozoaire qui peut être transmis à l'homme par diverses voies, dont la transfusion sanguine. Cette étude vise à étudier la séroprévalence de l'infection à T. gondii et les facteurs de risque associés chez les donneurs de sang sains en Tunisie. Au total, huit cents donneurs de sang sains de deux centres de transfusion sanguine du sud et de la côte tunisienne ont été analysés respectivement pour la recherche des anticorps IgG et IgM anti-T. gondii par immunofluorescence indirecte (IFA) et par dosage immuno-enzymatique (ELISA). Des questionnaires structurés ont été utilisés pour recueillir des informations sur les facteurs de risque d'infection à T. gondii pendant la collecte. La séroprévalence globale était de 44,4 % dont 352 (44 %) et 3 (0,4 %) étaient respectivement positifs pour les anticorps IgG et IgG/IgM anti-T. gondii. Une analyse multivariée a montré que la séropositivité à T. gondii était significativement associée au lieu de naissance (rapport de côtes ajusté [OR] = 2,72 ; intervalle de confiance à 95 % [IC] : 1,49­4,94) et à l'âge des donneurs (OR ajusté = 4,98 ; IC 95 % : 1,50­16,58) qui sont des facteurs de risque indépendants. De plus, le lavage des mains avant de manger (OR ajusté = 0,52 ; IC 95 % : 0,37­0,74) et vivre dans un milieu urbain (OR ajusté = 0,30 ; IC 95 % : 0,13­0,71) sont deux facteurs de protection. Cette étude a fourni les premières données sur la séroprévalence et l'épidémiologie de l'infection à T. gondii chez les donneurs de sang sains en Tunisie.

First isolation and molecular characterization of Toxoplasma gondii strains from human congenital toxoplasmosis cases in Monastir, Tunisia.

Toxoplasma gondii is a protozoon parasite that can cause severe clinical problems such as congenital toxoplasmosis. The distribution of T. gondii genotypes varies from one geographic area to another. So far, little is known about the parasite genotypes in Tunisia, North Africa. The present study aimed isolating and genotyping T. gondii from the amniotic fluid (AF) and placenta of pregnant women in Monastir, Tunisia. Amniotic fluid and/or placenta from 80 women who acquired toxoplasma infection during pregnancy were tested by PCR and/or mouse bioassay. Genotyping of T. gondii isolates from these samples was performed with 15 microsatellite markers. Four viable T. gondii strains were isolated from either the AF or placenta of four women. Specifically, strains TUN001-MON1 and TUN002-MON2 were isolated from both the AF and placenta, TUN003-AHA from only the placenta, and TUN004-NEL from only the AF. The four viable strains were not virulent for mice. Genotyping revealed that the four strains were type II strains. This is the first report on isolation and genotyping of T. gondii from AF human samples in Tunisia. Further studies focused on T. gondii genotyping on a larger number of human cases and on animals in Tunisia are needed to improve the knowledge and epidemiology of toxoplasmosis.