Amoebic serodiagnosis at Hospital Universiti Sains Malaysia (HUSM), Kelantan employs an indirect haemagglutination assay (IHA) which detects anti-Entamoeba histolytica antibodies in patients' serum samples. In an amoebiasis endemic area such as Kelantan, interpretation of a positive IHA result can be problematic due to the high background antibody levels. The TechLab E. histolytica II ELISA is a commercial kit for detection of specific Gal/GalNAc lectin antigen in stool samples, and has been reported to be able to detect the antigen in serum samples from patients with amoebic liver abscess (ALA). Thus in this study we investigated the usefulness of TechLab E. histolytica II ELISA for diagnosis of ALA by comparing it with IHA. This is a cross sectional study involving 58 suspected ALA patients who were admitted to the surgical ward, HUSM, Kelantan. The diagnosis of ALA was established based on clinical symptoms and signs, ultrasound and/or CT scan results. The serum specimens obtained from the patients were tested with IHA (Dade Behring Diagnostics, Marburg, Germany) and TechLab E. histolytica II ELISA (Techlab, Blacksburg, Virginia, USA) according to the manufacturers' instructions. Of the 58 patients, 72.4% (42) were positive by IHA and only 8.6% (5) were positive by the TechLab E. histolytica II ELISA. Agreement between the IHA and ELISA was poor (kappa value 0.019, p=0.691). There was also no correlation between ELISA results and IHA antibody titers. The TechLab E. histolytica II ELISA was not sensitive in detecting amoebic antigen in samples from ALA patients. In addition the results of the test did not correlate with the IHA anti-E. histolytica antibody titres. Therefore, the TechLab E. histolytica II ELISA was found not to be useful for serological diagnosis of ALA at HUSM.
A truncated form of surface antigen 2 (SAG2) of the protozoan parasite Toxoplasma gondii was cloned and expressed in the methylotrophic yeast Pichia pastoris. This recombinant antigen, designated as recSAG2-N, contained only the N-terminal half of the native SAG2. The recSAG2-N was secreted by the Pichia pastoris into the culture supernatant, and it was harvested by using the trichloroacetic acid precipitation method. Specificity of recSAG2-N was evaluated in western blot assays. Fifty human serum samples, including 32 from confirmed cases of toxoplasmosis, were tested. Results from the assays showed that recSAG2-N reacted with sera from the toxoplasmosis cases only. In vivo experiments showed that serum from mice which received recSAG2-N reacted with the native SAG2 of T. gondii.
Toxoplasma gondii is a protozoan parasite that is capable of causing a zoonotic disease, known as toxoplasmosis. Vertical transmission of T. gondii from the mother to the fetus, during pregnancy may cause severe complications to the developing fetus. This current study aimed to determine the seroprevalence and investigate the associated risk factors of Toxoplasma infection in pregnant women (n=219) visiting the antenatal clinic at UMMC. While the elevated level of anti-Toxoplasma IgG and IgM antibodies indicates the presence of infection, it fails to differentiate between a past and a recent infection. Thus, the study also demonstrates the usefulness of IgG avidity in validating the timing of infection. The serum samples were tested for the presence of anti-Toxoplasma IgG and IgM antibodies by ELISA test, and the seropositive samples for both anti-Toxoplasma IgG and IgM antibodies were further evaluated by IgG avidity. The results showed that the overall prevalence of T. gondii seropositivity was 34.7%. Of these, 30.6% (67/219) were positive for anti-Toxoplasma IgG antibody only, 2.3% (5/219) were positive for anti-Toxoplasma IgM only, and the remaining 1.8% (4/219) was positive for both anti-Toxoplasma IgG and IgM antibodies. All of the pregnant women who were positive for both anti-Toxoplasma IgG and IgM antibody were found to have past infection when evaluated by IgG avidity. In this study, Malay ethnicity and the number of existing previous children were significantly associated with T. gondii seropositivity (p<0.05). Based on these findings, information and education on the transmission and prevention of congenital toxoplasmosis are very crucial as a public health effort towards a healthier society.
Toxoplasma gondii (T. gondii) is a zoonotic infection that may be transmitted to human beings either by consumption of raw or uncooked meat or by ingesting oocysts. Toxoplasma organisms can cross blood placenta barrier and may result in congenital toxoplasmosis. About 80% of immunocompetent individuals do not show any clinical manifestations and are silent carriers of this disease. Pregnant women especially in highly prevalent areas are recommended to be screened for this disease in order to prevent the potential vertical transmission. To our knowledge no such study has been conducted in this region of Saudi Arabia. This study attempted to carry out two objectives: first, to find out the seroprevalence of T. gondii infection in pregnant women attending prenatal care services in our hospital; second, to find out risk factors associated with T. gondii seroprevalence in our patients. It was carried out in Teaching Hospital in Al-Kharj over a period of one year. All 306 pregnant women attending antenatal clinic were involved in the study. A pretested selfexplanatory questionnaire was filled out by the patients and their sera were collected to be tested for IgG and/or IgM against T. gondii. The results were then statistically analyzed using SPSS software and p-value was calculated using Pearson Chi Square test. Out of the 306 blood samples tested, 99 (32.4%) were seropositive for specific anti T. gondii IgG antibodies and 3(1%) were seropositive for IgM. This show that seroprevalence of T. gondii antibodies was high among pregnant women and the prevalence showed a significant association with age. The study recommends conducting educational programs to raise awareness among women about risk factors and precautions to be taken.
Toxoplasma gondii is an obligate intracellular protozoan parasite that causes toxoplasmosis in humans. To date, little is known about T. gondii infection among the indigenous community, particularly in East Malaysia. This study was conducted to determine the status of T. gondii infection and to investigate associated risk factors among the indigenous community of Sarawak, East Malaysia. The sociodemographic data was obtained using a pretested questionnaire. A serological test was done to detect the presence of specific IgM and IgG antibodies against T. gondii in serum samples. A nested polymerase chain reaction (PCR) was used to determine acute infection among seropositive individuals. The overall seroprevalence of T. gondii infection was 50% (95% CI = 43.3 - 56.7). From this subset, 40.1%, 5.7%, and 4.2% were positive for anti-T. Gondii IgG antibodies, IgM, and both IgG and IgM, respectively. Four seropositive samples were amplified through PCR. None of the pregnant women tested positive for T. gondii infection based on the serological and PCR assays. A significant association was found between age, low monthly household income, unemployment, usage of untreated water and close contact with T. gondii seropositive cats. These results provide basic information on T. gondii infection and may be useful for policymakers to initiate prevention and control programs, especially amongst pregnant women and women of childbearing age in the indigenous community.
Toxoplasma gondii is a world-widely spread zoonotic parasite. However, scarce knowledge is known about the prevalence of T. gondii infection in people in Hubei province, China. This study herein was to perform epidemiological investigation of T. gondii infection in people in this region. A total 12527 blood samples were obtained during 2015-2018, and were assayed for T. gondii antibodies of IgG and IgM, respectively by employing an indirect hemagglutination test (IHA). The results discovered that the prevalence of T. gondii in people was 2.44% and 6.1%, respectively based on antibodies of IgG and IgM, respectively. The prevalence was ranged from 0.3% to 5.4% during 2015-2018 based on IgM antibodies. For genders, the prevalence was 0.7% and 2.6% in males and females, respectively based on IgM antibodies. In different years, the prevalence was ranged from 4.9% to 14.0% based on IgG antibodies. The prevalence of T. gondii was 4.9% and 6.6% in males and femalesy based on IgG antibodies. The current results may be helpful for the implementation of preventive measures against Toxoplasma infection among people living in this region.
Toxoplasma gondii, a ubiquitous pathogen that infects nearly all warm-blooded animals and humans, can cause severe complications to the infected people and animals as well as serious economic losses and social problems. Here, one local strain (TgPIG-WH1) was isolated from an aborted pig fetus, and the genotype of this strain was identified as ToxoDB #3 by the PCR RFLP typing method using 10 molecular markers (SAG1, SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, C22-8, C29-2 and Apico). A comparison of the virulence of this isolate with other strains in both mice and piglets showed that TgPIG-WH1 was less virulent than type 1 strain RH and type 2 strain ME49 in mice, and caused similar symptoms to those of ME49 such as fever in piglets. Additionally, in piglet infection with both strains, the TgPIG-WH1 caused a higher IgG response and more severe pathological damages than ME49. Furthermore, TgPIG-WH1 caused one death in the 5 infected piglets, whereas ME49 did not, suggesting the higher virulence of TgPIG-WH1 than ME49 during piglet infection. Experimental infections indicate that the virulence of TgPIG-WH1 relative to ME49 is weaker in mice, but higher in pigs. This is probably the first report regarding a ToxoDB #3 strain from pigs in Hubei, China. These data will facilitate the understanding of genetic diversity of Toxoplasma strains in China as well as the prevention and control of porcine toxoplasmosis in the local region.
Toxoplasmosis is a zoonotic disease caused by Toxoplasma gondii that is prevalent in humans and animals. This study was aimed to determine the seroprevalence of T. gondii infection among hemato-oncology patients and its association with sociodemographic and behavioural characteristics. This cross-sectional study was conducted at the Hospital Universiti Sains Malaysia (USM) involving 56 blood samples from hemato-oncology patients. Anti-T. gondii IgG and IgM antibodies and IgG avidity were determined using enzyme-linked immunosorbent assays (ELISA). The association of T. gondii exposure, sociodemographic, and behavioural characteristics were assessed by a questionnaire and face-to-face interviews. Twenty-eight (50%) patients were seropositive for T. gondii antibodies, where 27 (48.21%) patients were IgG+/IgM- and one patient (1.79%) was IgG+/IgM+ with high avidity index, indicating infection of more than 20 weeks. A univariate analysis showed that age, gender, ethnicity, marital status, educational level, employment status, stem cell transplant, blood transfusion, close contact with cats, water supply, and consumption of undercooked meat were not significantly associated with Toxoplasma seropositivity (p < 0.05). Our study has demonstrated, for the first time, the serological evidence of T. gondii exposure among hemato-oncology patients in Hospital USM. Our findings indicated that latent toxoplasmosis was relatively prevalence among our patients. Therefore, serological screening tests should be considered for immunocompromised patients as well as the implementation of health education programmes to encourage a healthy lifestyle and the consumption of healthy food among them.
Toxoplasma gondii is a protozoan parasite that can infect all mammals, serving as intermediate hosts. The cause of congenital toxoplasmosis is transplacental transmission of the parasite to the foetus, resulting in wide range of manifestations from mild chorioretinitis to miscarriage. Its frequency can be reduced by early screening of pregnant women which is based mainly on tests for anti-Toxoplasma antibodies. We collected serum samples of 594 pregnant women (subjects) after taking their consent over a period of two years (2016-2018) and analyzed them for anti-Toxoplasma IgG by ELISA. The positive samples were then analyzed for IgG avidity test which could differentiate between recent and past infections. The seroprevalence was also correlated with the age of the subjects and their contact with cats. 162 subjects were found positive out of which only three showed a recent infection. After following up until delivery, one of them delivered a baby who had jaundice and was diagnosed with anti-Toxoplasma IgM at birth. The foetus of the second subject died in-utero, while the third woman delivered a normal baby after being given spiramycin when diagnosed with toxoplasmosis in the first trimester. It was found that most of the positive subjects had frequent contact with cats. Invasion of the parasite during third trimester resulted in death in-utero and jaundice. Most common cause of pregnancy wastage during our study was spontaneous abortions while pregnancy loss due to congenital anomalies was rare.
Recent reports indicate Neospora caninum has a possible role in causing abortions in sheep in New Zealand. Knowledge about the epidemiology of neosporosis in sheep is limited. This study aimed to adapt and validate a commercially available ELISA assay as an IgG avidity assay to discriminate between acute (primary and re-inoculated) and chronic N. caninum infections in sheep. In addition, it was used to compare the antibody avidity values between lambs from ewes inoculated with N. caninum either during the pregnancy or in the previous year. The avidity assay was undertaken by using 6M urea for the first wash after incubation with the primary antibody in the commercial ELISA (Chekit* Neospora antibody test kit, IDEXX Laboratories, Australia). Sequential serum samples were obtained from naïve ewes (n=16) experimentally inoculated with live N. caninum tachyzoites. All ewes were seropositive by two weeks post-inoculation and remained seropositive for 20 weeks post-inoculation. There was a linear relationship between time after inoculation and avidity values (p<0.05) over the first 24 weeks. In Week 4, all animals had avidity values <35% and by Week 8, 8/16 animals had avidity values of >35%. These results suggest that an avidity value of <35% indicates a recent primary infection while a value of >35% is indicative of a chronic infection. The assay was then validated using samples from other groups of experimentally inoculated sheep as well as samples from naturally infected ewes. When comparing sample to positive ratio (S/P) and avidity values from lambs born from recently inoculated ewes with those from ewes inoculated the previous year and re-inoculated in the current year, it was possible to differentiate the lambs at 2 weeks of age. Lambs from recently inoculated ewes had low S/P and avidity values at 2 weeks of age which increased by 12 weeks of age. In comparison, lambs from re-inoculated ewes had high S/P and avidity values at 2 weeks of age, due to maternal antibody influence but values were similar to those from lambs that were born from recently inoculated ewes at 12 weeks of age. Avidity values for four naturally infected ewes were all >60% indicating chronic infection. These results suggest that the assay is able to discriminate between recent and chronic infection in sheep as well as able to differentiate lambs with maternal immunity compared to their own de novo immunity. As such it can be utilized to understand the kinetics of N. caninum infection in sheep.
A study was conducted to determine the incidence of trypanosome infections in cattle in tsetse-free and tsetse-infested zones of the Amhara Region of northwest Ethiopia. A total of six sentinel herds were established and the cattle observed during a period of 8 consecutive months. The prevalence of seropositive cattle was high in both the tsetse-free and tsetse-infested zones. The average monthly incidence of trypanosome infection, determined using molecular diagnostic tools, was 20.9% and 25.7% in the tsetse-free and the tsetse-infested zones, respectively. In the tsetse-free, Trypanosoma vivax was responsible for 90.9% of the cattle trypanosome infections. In the tsetse-infested zone, Trypanosoma congolense and T. vivax contributed almost equally to the trypanosome infections in cattle. Trypanosome infection, regardless of species, resulted in anaemia as evidenced by a significant decrease in the packed cell volume of the infected animal. The outcome of this longitudinal study suggests that control of trypanosomiasis in the Amhara Region cannot be achieved by tsetse control alone. Supplemental measures to include drug therapy and biting fly control are discussed.