Prenatal diagnosis and prevention of toxoplasmosis in pregnant women in Northern Vietnam: study protocol

Abstract

BackgroundIn Vietnam, no systematic prenatal toxoplasmosis screening is in place, and only few studies have assessed the prevalence and importance of this zoonotic parasite infection. In addition, no studies have been conducted to assess the risk factors associated with toxoplasmosis. This study protocol was developed to determine the seroprevalence of toxoplasmosis in pregnant women in Hanoi and Thai Binh, Northern Vietnam, and to evaluate the association with risk factors and congenital toxoplasmosis. The protocol was developed in a way that it could potentially evolve into a countrywide prenatal diagnosis and prevention program, with the main focus on primary prevention.MethodsThe collaborating gynaecologists will invite eligible pregnant women attending antenatal care for the first time to participate in the study. At first consult, information about toxoplasmosis and its prevention will be provided. All participants will be asked to fill in a questionnaire, which is designed to analyse socio-demographic and biologically plausible risk factors associated with toxoplasmosis, and blood samples will be collected to determine the seroprevalence of toxoplasmosis in pregnant women. In case there is suspicion of a primary infection during pregnancy, the concerned women will be followed-up by the gynaecologists according to a predefined protocol. Every participant will be informed on her serological status, risk factors and prevention measures and is offered appropriate medical information and medical follow-up if required.DiscussionThe hypothesis is that congenital toxoplasmosis is an important but currently under-diagnosed public health problem in Vietnam. This study can strengthen sustainable control of toxoplasmosis in Vietnam, provide a protocol for prenatal diagnosis, boost overall awareness, improve the knowledge about toxoplasmosis prevention and can be essential for evidence-based health policy.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-017-2446-1) contains supplementary material, which is available to authorized users.

Sero-epidemiological status and risk factors of toxoplasmosis in pregnant women in Northern Vietnam

“…In case of a seroconversion the ISAGA ensures very early detection of IgM yet the test is very sensitive to residual IgM, which can persist for more than 1 year (according to the manufacturer). By retesting and following up the patients, conducting confirmatory tests, complementing the results with additional diagnostic techniques, interpretation of the results taking into account the results of all (other) tests performed and the patient’s history, and thorough consultation and discussion with all stakeholders involved, our protocol [17] took this into account.…”

“…Thai Binh is known as the “cat province” because of its dense cat population - pets, stray cats, and cats for meat consumption - in contrast to the rest of Vietnam [16]. More background information, eligibility criteria and the full study protocol are described in Smit et al [17].…”

“…Persisting IgG antibodies 9 months to 1 year after birth are an indication for CT but only if the mother is also found IgG positive in the perinatal period [21]. More information about the laboratory procedures and the full study protocol including (diagnostic) follow-up are described in Smit et al [17].…”

Comparison of an in house and a commercial real-time polymerase chain reaction targeting Toxoplasma gondii RE gene using various samples collected from patients in Turkey

“…Toxoplasmosis can be diagnosed using histological, serological, and molecular methods [1, 3–6]. In recent years, serological and molecular diagnostic methods are frequently used.…”

Prevalência e fatores associados à toxoplasmose em gestantes de um município do interior do estado de São Paulo

“…A imunoglobulina G (IgG), é descrita como uma classe de imunoglobulinas composta por várias subclasses, que surgem em dimensões durante a infecção do protozoário apresentando uma sequência numérica: IgG1, IgG2, IgG3 e IgG4, frequente em humanos. Diversos estudos (ABAMECHA et al, 2016;ALMUSHAIT et al, 2014;ALVAREZ et al;AVCI et al, 2015;AVELINO et al, 2014 ;CÁRDENA et al, 2015;DENTICO et., 2011;FONSECA et al, 2012;FREITAS et al, 2017;LABOUDI et al, 2017;MOSAWI et al, 2011;MWAMBE et al, 2013;NOGAREDA et al, 2014;PESSANHA et al, 2011;SHAHIDA et al, 2019;SMIT et al, 2019;TAVARES et al, 2012) da Toxoplasmose humana tem evidenciado que IgG1 é o primeiro a ser ativado, com predominância no plasma, enquanto que os anticorpos IgG2 e IgG3 são observados em baixos níveis, com impossibilidade de detecção do anticorpo IgG4 .…”