[Survey on Toxoplasma gondii infections among three types of populations in Wuxi City]

OBJECTIVE

To investigate the seroprevalence of Toxoplasma gondii infections among patients with rheumatoid arthritis, malignant tumors and schizophrenia in Wuxi City, so as to provide data support for the control of toxoplasmosis in these patients.

METHODS

A total of 205 cases with definitive diagnosis of rheumatoid arthritis, 257 cases with definitive diagnosis of malignant tumors and 235 cases with definitive diagnosis of schizophrenia were recruited, while 250 healthy volunteers served as controls. The demographic features were captured from the study subjects and serum samples were collected. The serum IgG and IgM antibodies against T. gondii were detected using an enzyme-linked immunosorbent assay (ELISA) in all study subjects, and the positive rates of anti-T. gondii IgG and IgM antibodies were compared between the patients and controls.

RESULTS

The seroprevalence of the anti-T. gondii IgG antibody was 20.98%, 24.12% and 24.68% in patients with rheumatoid arthritis, malignant tumors and schizophrenia, which were all significantly greater than in healthy controls (χ² = 31.54, 42.12 and 42.98, all P values < 0.01), and the seroprevalence of the anti - T. gondii IgM antibody was 1.46%, 2.72% and 1.70% among patients with rheumatoid arthritis, malignant tumors and schizophrenia, which were all significantly higher than in healthy controls (χ² = 0.06, 1.52 and 0.21, all P values > 0.05).

CONCLUSIONS

The patients with rheumatoid arthritis, malignant tumors and schizophrenia present with higher seroprevalence of the anti-T. gondii IgG antibody than healthy controls in Wuxi regions. Screening of T. gondii infections among the patients with rheumatoid arthritis, malignant tumors and schizophrenia should be intensified to prevent the damages caused by T. gondii infections.

Knowledge and practices regarding toxoplasmosis in housewives: A cross sectional study in a northern Mexican city

We aimed to determine the knowledge and practices regarding toxoplasmosis among housewives in the northern Mexican city of Durango. One hundred eighty-five women (mean age: 41.27 ± 12.40 years old) with an occupation of housewife were studied. A self-administered questionnaire was used. This tool included items about the parasite Toxoplasma gondii, its transmission routes, general clinical, diagnostic, and treatment aspects of toxoplasmosis, and practices to avoid infection. A minority (<10%) of women knew about the parasite, the disease, how the transmission occurs, the clinical manifestations, how an infection is diagnosed, the treatment, and how to avoid toxoplasmosis. Some women knew that cats can transmit T. gondii infection (20%), and that the parasite can be found in cat feces (20.5%). Only 7.6% of women knew that infection with T. gondii can be transmitted by consumption of contaminated food or water. Only 1.1% of women knew about the prevalence of T. gondii infection. Some (4.9%) women used to taste raw meat while cooking, and 7.6% used to undercook meat. In addition, 20% of women used to eat raw dried meat, and 13.5% consumed untreated water. Less than 90% of women always washed their hands before cooking, and washed fruits or vegetables. The majority (75.1%) of women never wore gloves when handling raw meat. About one quarter (27.6%) of women always froze meat. And 16.2% of women cleaned cat feces. This is the first study regarding knowledge and practices about toxoplasmosis in housewives. Poor knowledge regarding T. gondii infection, toxoplasmosis, and practices to avoid infection among the housewives studied was found. High risk practices for infection were identified. Strategies to improve toxoplasmosis-related knowledge and practices to avoid T. gondii infection and its sequelae in housewives are highly needed.

Virus-like particles containing multiple antigenic proteins of Toxoplasma gondii induce memory T cell and B cell responses

Although the efforts to develop vaccine against Toxoplasma gondii infection were made for decades, there is currently no licensed vaccine available for humans. Upon discovering a number of T or B cell epitope regions from T. gondii IMC, ROP18 and MIC8, multi-antigen VLPs or combination VLPs were generated. Mice immunized with multi-antigen VLPs or combination VLPs were challenge infected with T. gondii (ME49). T. gondii-specific IgG, IgG isotypes and IgA antibody responses, memory T and B cell responses and protection were evaluated. All the mice survived upon T. gondii challenge infection by multi-antigen VLPs vaccination. Vaccinated mice elicited higher levels of parasite-specific IgG and IgG2a antibody responses in sera, IgA antibody responses in feces, CD4+ and CD8+ T cell responses, and cytokines (IFN-γ, IL-10) responses compared to combination VLPs. In particular, the multi-antigen VLPs vaccination showed significantly higher levels of antibody secreting cell (ASC) responses, CD4+ and CD8+ effector memory T cells, and memory B cells than combination VLPs. Multi-antigen VLPs vaccination showed significant reduction of brain cyst counts and size, and all mice survived. Prediction and analysis of epitopes have indicated that IMC, ROP18 and MIC8 showed partially overlapping epitopes for T and B cells. Our results indicated that antibody responses, memory T and B cells induced by multi-antigen VLPs vaccination might contribute to the complete protection upon T. gondii (ME49) challenge infection.

IL-17 and IL-22 elicited by a DNA vaccine encoding ROP13 associated with protection against Toxoplasma gondii in BALB/c mice

Toxoplasma gondii, an intracellular parasitic protozoan, is capable of infecting man and all warm-blooded animals. Cell-mediated immunity is vital in mounting protective responses against T. gondii infection. Recent studies have shown that T-helper (Th) 17 responses may play a key role in parasite control. In this current study, we constructed a DNA vaccine encoding T. gondii ROP13 in a pcDNA vector. Groups of BALB/c mice were immunized intramuscularly with pcROP13 or controls and challenged with the RH strain of T. gondii. The results showed that immunization with pcROP13 could elicit an antibody response against T. gondii. The expression of the canonical Th17 cytokines, interleukin (IL)-17 and IL-22, were significantly increased after immunization with pcROP13 compared with control groups ( p < 0.05). Furthermore, vaccination resulted in a significant decrease in parasite load ( p < 0.05). The induction of Th17 related cytokines, using a ROP13 DNA vaccine, against T. gondii should be considered as a potential vaccine approach for the control of toxoplasmosis.

The One Health Approach to Toxoplasmosis: Epidemiology, Control, and Prevention Strategies

One Health is a collaborative, interdisciplinary effort that seeks optimal health for people, animals, plants, and the environment. Toxoplasmosis, caused by Toxoplasma gondii, is an intracellular protozoan infection distributed worldwide, with a heteroxenous life cycle that practically affects all homeotherms and in which felines act as definitive reservoirs. Herein, we review the natural history of T. gondii, its transmission and impacts in humans, domestic animals, wildlife both terrestrial and aquatic, and ecosystems. The epidemiology, prevention, and control strategies are reviewed, with the objective of facilitating awareness of this disease and promoting transdisciplinary collaborations, integrative research, and capacity building among universities, government agencies, NGOs, policy makers, practicing physicians, veterinarians, and the general public.

A social cost-benefit analysis of two One Health interventions to prevent toxoplasmosis

In the Netherlands, toxoplasmosis ranks second in disease burden among foodborne pathogens with an estimated health loss of 1,900 Disability Adjusted Life Years and a cost-of-illness estimated at €45 million annually. Therefore, effective and preferably cost-effective preventive interventions are warranted. Freezing meat intended for raw or undercooked consumption and improving biosecurity in pig farms are promising interventions to prevent Toxoplasma gondii infections in humans. Putting these interventions into practice would expectedly reduce the number of infections; however, the net benefits for society are unknown. Stakeholders bearing the costs for these interventions will not necessary coincide with the ones having the benefits. We performed a Social Cost-Benefit Analysis to evaluate the net value of two potential interventions for the Dutch society. We assessed the costs and benefits of the two interventions and compared them with the current practice of education, especially during pregnancy. A 'minimum scenario' and a 'maximum scenario' was assumed, using input parameters with least benefits to society and input parameters with most benefits to society, respectively. For both interventions, we performed different scenario analyses. The freezing meat intervention was far more effective than the biosecurity intervention. Despite high freezing costs, freezing two meat products: steak tartare and mutton leg yielded net social benefits in both the minimum and maximum scenario, ranging from €10.6 million to €31 million for steak tartare and €0.6 million to €1.5 million for mutton leg. The biosecurity intervention would result in net costs in all scenarios ranging from €1 million to €2.5 million, due to high intervention costs and limited benefits. From a public health perspective (i.e. reducing the burden of toxoplasmosis) and the societal perspective (i.e. a net benefit for the Dutch society) freezing steak tartare and leg of mutton is to be considered.

A review on inactivation methods of Toxoplasma gondii in foods

Toxoplasmosis is an infection caused by Toxoplasma gondii, a widespread zoonotic protozoan which poses a great threat to human health and economic well-being worldwide. It is usually acquired by ingestion of water contaminated with oocysts from the feces of infected cats or by the ingestion of raw or undercooked foodstuff containing tissue cysts. The oocyst can contaminate irrigation water and fresh edible produce. It is estimated that approximately one-third of the human population worldwide harbor this parasite. Infection with T. gondii is an important cause of diseases of the central nervous system and the eye in immunocompromised and immunocompetent individuals. The purpose of this study was to evaluate the efficacy and applicability of thermal (heating, cooking, freezing and low temperature), non-thermal (high pressure processing, ionizing irradiation and curing) and chemical and biochemical (disinfection, essential oils and biochemical methods such as enzymes, nanoparticles, antibiotics and immune response) treatments for the inactivation, inhabitation or to kill T. gondii in foodstuff intended for public consumption and under experimental conditions.

Evaluation of Protective Immune Response Induced by a DNA Vaccine Encoding GRA8 against Acute Toxoplasmosis in a Murine Model

Toxoplasma gondii is an apicomplexan zoonotic protozoan parasite that infects most species of warm-blooded animals, including humans. The heavy incidence and severe or lethal damage caused by T. gondii infection clearly indicate a need for the development of an effective vaccine. T. gondii GRA8 is a member of the dense granules protein family and is used as a marker of acute infection. In the present study, we evaluated the protective immunity induced by DNA vaccination based on a recombinant eukaryotic plasmid, pDsRed2-GRA8, against acute toxoplasmosis in mice. BALB/c mice were intramuscularly immunized with the pDsRed2-GRA8 plasmid and then challenged by infection with the highly virulent GFP-RH strain of T. gondii. The specific immune responses and protective efficacy against T. gondii of this vaccine were analyzed by measuring cytokine and serum antibody titers, splenocyte proliferation assays, and the survival times of mice after challenge. Our results showed that mice immunized with pDsRed2-GRA8 demonstrated specific humoral and cellular responses, induced higher IgG antibody titers with predominant IgG2a production; increased levels of IL-10, IL-12 (p70), IFN-γ, TNF-α, and splenocyte proliferation; and prolonged survival times compared to those of control mice. The present study showed that DNA immunization with pDsRed2-GRA8 induced humoral and cellular immune responses, and all immunized mice showed greater Th1-type immune responses and longer survival times than those of control mice. These results indicated that T. gondii GRA8 DNA immunization induces a partial protective effect against acute toxoplasmosis.

Risk Assessment of Human Toxoplasmosis Associated with the Consumption of Pork Meat in Italy

Toxoplasmosis is a cosmopolitan disease and has a broad range of hosts, including humans and several wild and domestic animals. The human infection is mostly acquired through the consumption of contaminated food and pork meat has been recognized as one of the major sources of transmission. There are, however, certain fundamental differences between countries; therefore, the present study specifically aims to evaluate the exposure of the Italian population to Toxoplasma gondii through the ingestion of several types of pork meat products habitually consumed in Italy and to estimate the annual number of human infections within two subgroups of the population. A quantitative risk assessment model was built for this reason and was enriched with new elements in comparison to other similar risk assessments in order to enhance its accuracy. Sensitivity analysis and two alternative scenarios were implemented to identify the factors that have the highest impact on risk and to simulate different plausible conditions, respectively. The estimated overall average number of new infections per year among adults is 12,513 and 92 for pregnant women. The baseline model showed that almost all these infections are associated with the consumption of fresh meat cuts and preparations (mean risk of infection varied between 4.5 × 10^-5 and 5.5 × 10^-5 ) and only a small percentage is due to fermented sausages/salami. On the contrary, salt-cured meat products seem to pose minor risk but further investigations are needed to clarify still unclear aspects. Among all the considered variables, cooking temperature and bradyzoites' concentration in muscle impacted most the risk.

[Epidemic situation and control strategy of major food - borne parasitic diseases in Guangxi Zhuang Autonomous Region]

Food-borne parasitic diseases have become a public health problem for social economy and health care. In this paper, the epidemic situation of major food-borne parasitic diseases in Guangxi Zhuang Autonomous Region, such as toxoplasmosis and clonorchiasis, are reviewed, and the countermeasures of prevention and control are put forward.

Parasite Carbohydrate Vaccines

Vaccination is an efficient means of combating infectious disease burden globally. However, routine vaccines for the world's major human parasitic diseases do not yet exist. Vaccines based on carbohydrate antigens are a viable option for parasite vaccine development, given the proven success of carbohydrate vaccines to combat bacterial infections. We will review the key components of carbohydrate vaccines that have remained largely consistent since their inception, and the success of bacterial carbohydrate vaccines. We will then explore the latest developments for both traditional and non-traditional carbohydrate vaccine approaches for three of the world's major protozoan parasitic diseases-malaria, toxoplasmosis, and leishmaniasis. The traditional prophylactic carbohydrate vaccine strategy is being explored for malaria. However, given that parasite disease biology is complex and often arises from host immune responses to parasite antigens, carbohydrate vaccines against deleterious immune responses in host-parasite interactions are also being explored. In particular, the highly abundant glycosylphosphatidylinositol molecules specific for Plasmodium, Toxoplasma, and Leishmania spp. are considered exploitable antigens for this non-traditional vaccine approach. Discussion will revolve around the application of these protozoan carbohydrate antigens for vaccines currently in preclinical development.

Vaccination with Recombinant Microneme Proteins Confers Protection against Experimental Toxoplasmosis in Mice

Toxoplasmosis, a zoonotic disease caused by Toxoplasma gondii, is an important public health problem and veterinary concern. Although there is no vaccine for human toxoplasmosis, many attempts have been made to develop one. Promising vaccine candidates utilize proteins, or their genes, from microneme organelle of T. gondii that are involved in the initial stages of host cell invasion by the parasite. In the present study, we used different recombinant microneme proteins (TgMIC1, TgMIC4, or TgMIC6) or combinations of these proteins (TgMIC1-4 and TgMIC1-4-6) to evaluate the immune response and protection against experimental toxoplasmosis in C57BL/6 mice. Vaccination with recombinant TgMIC1, TgMIC4, or TgMIC6 alone conferred partial protection, as demonstrated by reduced brain cyst burden and mortality rates after challenge. Immunization with TgMIC1-4 or TgMIC1-4-6 vaccines provided the most effective protection, since 70% and 80% of mice, respectively, survived to the acute phase of infection. In addition, these vaccinated mice, in comparison to non-vaccinated ones, showed reduced parasite burden by 59% and 68%, respectively. The protective effect was related to the cellular and humoral immune responses induced by vaccination and included the release of Th1 cytokines IFN-γ and IL-12, antigen-stimulated spleen cell proliferation, and production of antigen-specific serum antibodies. Our results demonstrate that microneme proteins are potential vaccines against T. gondii, since their inoculation prevents or decreases the deleterious effects of the infection.

Phosphatidylthreonine and Lipid-Mediated Control of Parasite Virulence

The major membrane phospholipid classes, described thus far, include phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn), phosphatidylserine (PtdSer), and phosphatidylinositol (PtdIns). Here, we demonstrate the natural occurrence and genetic origin of an exclusive and rather abundant lipid, phosphatidylthreonine (PtdThr), in a common eukaryotic model parasite, Toxoplasma gondii. The parasite expresses a novel enzyme PtdThr synthase (TgPTS) to produce this lipid in its endoplasmic reticulum. Genetic disruption of TgPTS abrogates de novo synthesis of PtdThr and impairs the lytic cycle and virulence of T. gondii. The observed phenotype is caused by a reduced gliding motility, which blights the parasite egress and ensuing host cell invasion. Notably, the PTS mutant can prevent acute as well as yet-incurable chronic toxoplasmosis in a mouse model, which endorses its potential clinical utility as a metabolically attenuated vaccine. Together, the work also illustrates the functional speciation of two evolutionarily related membrane phospholipids, i.e., PtdThr and PtdSer.

An exclusive membrane lipid, phosphatidylthreonine, is revealed to be naturally abundant in the widespread protist parasite Toxoplasma gondii, where it has evolved adaptively and is essential for parasite virulence.

Lipids are essential constituents of biological membranes, and most organisms across the tree of life use a relatively limited repertoire of lipids in their membranes. This work reveals the natural and abundant presence of an exclusive lipid phosphatidylthreonine (PtdThr) in Toxoplasma gondii, a ubiquitous protozoan parasite of humans and animals. PtdThr is made by a novel parasite-specific enzyme, PtdThr synthase, which has evolved from the widespread enzyme phosphatidylserine synthase. The study shows that PtdThr is required for asexual reproduction and virulence of the parasite in vivo, and a metabolically attenuated mutant strain of Toxoplasma lacking PtdThr can protect vaccinated mice against acute and currently incurable chronic infection. This discovery demonstrates adaptive “speciation” of PtdThr from an otherwise near-universal membrane lipid phosphatidylserine and reveals de novo PtdThr synthesis in T. gondii as a potential drug target.

[Expression of Cocktail DNA Vaccine Comprising Toxoplasma gondii SAGI, MIC3 and ROP2 Using Fluorescent Protein-Reporting Vectors and Evaluation of Its Immunogenicity]

OBJECTIVE

To construct a cocktail DNA vaccine that expresses multiple genes of Toxoplasma gondii and investigate its immunogenicity in mice.

METHODS

Genes for surface antigens (SAG), microneme(MIC), and rhoptry protein(ROP) were amplified from genomic DNA of T. gondii and then cloned separately into eukaryotic fluorescent protein expression vectors pShuttle-CMV-MCS-EFlα-AmCyan, pLVX-IRES-Zsgreen and pLVX-IRES-rfp, to construct expression plasmids pShuttle-SAG1, pLVX-Zsgreen-MIC3 and pLVX-rfp-ROP2. 293F cells were transfected with a combination of the three plasmids using the polyethylenimine (PEI) method. Forty-eight hours later, the expression of the three genes was observed under a fluorescence microscope. In addition, 30 C57BL/6 mice were randomized to receive intramuscular injection of saline (50 pA, group A), pShuttle+pLVX-Zsgreen+pLVX-rfp empty plasmids(2 μg/μL, 17 μL of each, group B) and pShuttle-SAG1+pLVX-Zsgreen-MIC3+ pLVX-rfp-ROP2 recombinant plasmid (2 μg/μL, 17 μL of each, group C). After 28 days, anti-T. gondii antibody in mouse serum was detected by ELISA, to evaluate the immunogenicity of the vaccine.

RESULTS

The SAG1, MIC3 and ROP2 genes were amplified from the genomic DNA, with product sizes of 1, 1.1 and 1.7 kb. The eukaryotic expression plasmids pShuttle-SAG1, pLVX-Zsgreen-MIC3 and pLVX-rfp-ROP2 were constructed, and the corresponding fluorescences (blue, green and red) were observed after transfection. On day 28 after mouse vaccination, ELISA showed that the mean A(450) values for serum IgG in groups A, B and C were (0.620±0.029), (0.741±0.040) and (1.561±0.131), respectively, with the group C value being significantly higher than the others (P<0.01).

CONCLUSION

The cocktail DNA vaccine comprising T. gondii SAG1, MIC3 and ROP2 shows promising immunogenicity in mice, and the fluorescent protein expression vectors are reliable tools for expression of the target genes.

Atovaquone for Prophylaxis of Toxoplasmosis after Allogeneic Hematopoietic Stem Cell Transplantation

Toxoplasmosis and infections by other opportunistic agents such as Pneumocystis jirovecii constitute life-threatening risks for patients after allogeneic hematopoietic stem cell transplantation. Trimethoprim/sulfamethoxazole (TMP-SMX) has been well established for post-transplant toxoplasmosis and pneumocystis prophylaxis, but treatment may be limited due to toxicity. We explored atovaquone as an alternative and compared it with TMP-SMX regarding toxicity and efficacy during the first 100 days after transplantation in 155 consecutive adult stem cell recipients. Eight patients with a prior history of TMP-SMX intolerance received atovaquone as first-line prophylaxis. TMP-SMX was used for 141 patients as first-line strategy, but 13 patients (9.2%) were later switched to atovaquone due to TMP-SMX toxicity or gastrointestinal symptoms. No active toxoplasmosis or active P. jirovecii infection developed under continued prophylaxis with either TMP-SMX or atovaquone. However, for reasons of TMP-SMX and/or atovaquone toxicity, 7 patients were unable to tolerate any efficacious toxoplasmosis prophylaxis and therefore obtained inhalative pentamidine as P. jirovecii prophylaxis but no toxoplasmosis prophylaxis. Importantly, 2 of these patients developed severe toxoplasmosis. In summary, atovaquone appears as a valid alternative for at least some post-transplant patients who cannot tolerate TMP-SMX. This should be further confirmed by multicenter trials.

Survey of obstetrician-gynecologists in the United States about toxoplasmosis: 2012 update

PURPOSE

Toxoplasmosis, caused by the parasite Toxoplasma gondii, can have serious impacts on fetal development in the setting of acute maternal primary infection. The American College of Obstetricians and Gynecologists (ACOG) sought to determine current knowledge, practices, opinions, and educational preferences regarding T. gondii infection in pregnancy among ACOG members practicing prenatal care.

METHODS

ACOG sent a survey to 1,056 members chosen by stratified random sampling from membership lists, including 370 participants and 686 non-participants in the Collaborative Ambulatory Research Network (CARN). Mailings were sent up to four times to nonresponders.

RESULTS

Survey minimum response rates were 40.3% (CARN) and 19.7% (non-CARN); response rates adjusted for imputed non-eligibility were 59.7% (CARN) and 22.6% (non-CARN). Among providers, 80.2% had diagnosed no acute maternal T. gondii infections in the past 5 years, 12.7% correctly identified the screening role of the Toxoplasma avidity test, 42.6% performed serologic T. gondii screening for at least some asymptomatic pregnant women, and 62.1% of those who so did used appropriate approaches. Providers in the northeastern United States were 2.02 times more likely to routinely screen than those in the west (p = 0.025) and female providers were 1.48 times more likely than male providers (p = 0.047). The potential educational interventions considered useful by the most practitioners were updated ACOG guidelines on screening (81.4%) and management (71.7%) for acute T. gondii infection in pregnancy.

CONCLUSIONS

ACOG members would benefit from educational efforts targeted at risk factor counseling and screening approaches.

[Study and application of surface antigen in tachyzoites of Toxoplasma gondii]

Toxoplasma gondii is an intracellular protozoan parasite that infects all warm-blooded animals. The surface antigens of T. gondii with the potential for application as antigens of diagnosis and vaccines have been studied extensively in recent years, especially for P43, P35, P30, P23 and P22. The studies on the surface antigen in tachyzoites of T. gondii are reviewed in this paper.

What information do Dutch midwives give clients about toxoplasmosis, listeriosis and cytomegalovirus prevention? An exploratory study of videotaped consultations

OBJECTIVE

To assess information provided by midwives about methods to prevent toxoplasmosis, listeriosis and cytomegalovirus, and whether the amount of provided information varied according to clients' and midwives' characteristics.

METHODS

Intake consultations with 229 clients in four midwifery practices were videotaped between August 2010 and April 2011. Videotaped intake consultations, where infectious disease prevention were discussed, were evaluated, using a specifically designed nine-item scoring tool. Midwives and clients filled in a questionnaire about their background characteristics. Multilevel linear regression analysis was performed to establish associations between the amount of information provided and clients' and midwives' characteristics.

RESULTS

In total 172 consultations with fifteen midwives were suitable for analyses. Information about not eating raw or undercooked meat and not consuming unpasteurized dairy products was provided most often. Information about not sharing eating utensils with small children and thoroughly reheating all ready-to-eat foods were rarely provided. More information was provided when the client was a primigravidae or the consultation lasted longer than 50min.

CONCLUSION

Information on infectious disease prevention given to pregnant women by primary care midwives was insufficient; especially for cytomegalovirus prevention.

PRACTICE IMPLICATIONS

A guideline for professionals on preventable infectious diseases may be useful to inform pregnant women properly.

Neglected parasitic infections in the United States: toxoplasmosis

Toxoplasma gondii is a leading cause of severe foodborne illness in the United States. Population-based studies have found T. gondii infection to be more prevalent in racial/ethnic minority and socioeconomically disadvantaged groups. Soil contaminated with cat feces, undercooked meat, and congenital transmission are the principal sources of infection. Toxoplasmosis-associated illnesses include congenital neurologic and ocular disease; acquired illness in immunocompetent persons, most notably ocular disease; and encephalitis or disseminated disease in immunosuppressed persons. The association of T. gondii infection with risk for mental illness is intriguing and requires further research. Reduction of T. gondii in meat, improvements in hygiene and food preparation practices, and reduction of environmental contamination can prevent toxoplasmosis, but more research is needed on how to implement these measures. In addition, screening and treatment may help prevent toxoplasmosis or reduce the severity of disease in some settings.

[Pregnancy and vaccinoprevention]

Vaccinations protect woman and her fetus against different infectious diseases, but their application on pregnant should be extremely responsible. In this review I present information about some infectious diseases and vaccines during pregnancy. Women, planning to get pregnant should be advised to do serological tests in order to find out their immune status against some infections, leading to fetal congenital malformations (rubella, chicken pox, hepatitis B) and if necessary to get vaccinated at least a month before pregnancy. Despite the lack of vaccines against Cytomegalovirus (CMV), parvovirus 19 and Toxoplasma gondii it is good to know woman's immune status against these infections in order to clarify the clinical approach in case of future contact with sick or carriers. Parvovirus 19 could cause fetal death, while CMV could be transmitted to the child. Immune women wouldn't get sick and wouldn't transmit Toxoplasmagondii to the fetus during pregnancy. Recommended vaccines before pregnancy include vaccines against flu, human papilloma virus, MMR (morbilli, measles, rubella), Tdap (tetanus, diphtheria, whooping cough), chicken pox. CDC-Atlanta recommends during pregnancy two vaccines--against flu, in case it wasn't done before pregnancy, and Tdap during every pregnancy between 27-th and 36-th gestation week. Whooping cough is very dangerous for the baby during the first two months after birth, while it is not yet vaccinated. From this point of view it is of best interest of the mother to have strong immunity in order to transfer antibodies during breastfeeding, as well as for the father and the rest who will take care for the newborn child to be vaccinated against whooping cough. During pregnancy vaccinations against tuberculosis, morbilli, measles, rubella, meningococcal disease, typhoid fever and chicken pox are contraindicated. In case of contact vaccinations against rabies, anthrax, small pox, poliomyelitis and yellow fever should be taken into consideration. Immediately after birth, if the vaccination against whooping cough is missed young mother vaccination is recommended. The vaccination is one of the greatest achievements of the modern medicine, but it is still an object of vigorous attacks, concerning used products safety. One of the most spreading fears is about sterility after vaccination. Over a period of three years (2009-2012) 563 women were vaccinated by SACMEH against HPV. Forty two of them (13.40%) interrupt vaccination due to pregnancy (18 of them after the first shot and 24 after the second shot). Our observations show, that this vaccine is carried out good by the patients, tit is safe and does not cause sterility.

Evaluation on the immune response induced by DNA vaccine encoding MIC8 co-immunized with IL-12 genetic adjuvant against Toxoplasma gondii infection

OBJECTIVE

To examine the immunoprotection effect induced by MIC8 DNA vaccine co-immunized with a plasmid encoding murine IL-12 (pcIL-12) as an adjuvant in mice against the challenge of Toxoplasma gondii.

METHODS

The gene sequence encoding MIC8 of T. gondii RH strain was inserted into eukaryotic expression vector pcDNA3.1 to construct the pcMIC8 expression plasmid. The recombinant plasmid was transfected into HeLa cells to test its expression and the recombinant protein was then characterized by Western blotting. Eighty Kunming mice were randomly divided into 5 groups (16 per group): 3 control groups (PBS, pcDNA3.1, and pcIL-12), pcMIC8 group, and pcMIC8 plus pcIL-12 group. Mice in the pcMIC8 plus pcIL-12 group were co-injected intramuscularly at a dosage of 100 microl each of pcMIC8 and pcIL-12 suspended in 100 microg sterile PBS. Mice in other groups were inoculated with PBS, pcDNA3.1, pcIL-12, and pcMIC8 respectively following the same protocol. All the mice received three immunizations at 2-week intervals. Serum samples were collected on day 0, 13, 27, 41, and 55 before each inoculation for determining antibody IgG, IgG subclass IgG2a. Four weeks after the final immunization, IFN-gamma and IL-4 levels in splenocytes cultures from immunized mice were detected by ELISA. The mice were challenged with 10(3) tachyzoites of the virulent T. gondii RH strain three weeks after the last immunization to observe the survival time.

RESULTS

Western blotting showed that the protein extracts in HeLa cells upon transfection with pcMIC8 were effectively expressed in cells. The levels of IgG (0.51 +/- 0.028) and IgG2a (0.261 +/- 0.04)(on day 55) in mice immunized with pcMIC8 plus pcIL-12 were higher than pcMIC8 group (497.65 +/- 98.15) and control groups (PBS 47.18 +/- 2.73, pcDNA3.1 50.08 +/- 4.62, pcIL-12 118.15 +/- 12.73) (P < 0.05). There was no significant difference in the level of IgG 1 and IL-4 among the five groups (P > 0.05). After a lethal challenge of T. gondii RH strain, the survival time in mice immunized with pcMIC8 plus pcIL-12 (15d) was prolonged in comparison to that of pcMIC8 (10d) and control groups (PBS 5 d, pcDNA3.1 6d, pcIL-12 8 d) (P < 0.05).

CONCLUSION

The immune responses induced by the combined use of the recombinant plasmid encoding MIC8 of T. gondii with murine IL-2 gene adjuvant can be enhanced.

Zoonotic infections in Alaska: disease prevalence, potential impact of climate change and recommended actions for earlier disease detection, research, prevention and control

Over the last 60 years, Alaska's mean annual temperature has increased by 1.6°C, more than twice the rate of the rest of the United States. As a result, climate change impacts are more pronounced here than in other regions of the United States. Warmer temperatures may allow some infected host animals to survive winters in larger numbers, increase their population and expand their range of habitation thus increasing the opportunity for transmission of infection to humans. Subsistence hunting and gathering activities may place rural residents of Alaska at a greater risk of acquiring zoonotic infections than urban residents. Known zoonotic diseases that occur in Alaska include brucellosis, toxoplasmosis, trichinellosis, giardiasis/cryptosporidiosis, echinococcosis, rabies and tularemia. Actions for early disease detection, research and prevention and control include: (1) determining baseline levels of infection and disease in both humans and host animals; (2) conducting more research to understand the ecology of infection in the Arctic environment; (3) improving active and passive surveillance systems for infection and disease in humans and animals; (4) improving outreach, education and communication on climate-sensitive infectious diseases at the community, health and animal care provider levels; and (5) improving coordination between public health and animal health agencies, universities and tribal health organisations.