Preconception Seroconversion and Maternal Seronegativity at Delivery Do Not Rule Out the Risk of Congenital Toxoplasmosis

Chemla, Cathy; Villena, Isabelle; Aubert, Dominique; Hornoy, P.; Dupouy, D.; Leroux, B; Bory, J; Pinon, J. M.

doi:10.1128/cdli.9.2.489-490.2002

Cited by 18 publications

(14 citation statements)

References 13 publications

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“…It is therefore justifiable to decrease the threshold for exclusion of a recent infection of less than 4 months to 0.2 and use the company threshold of 0.3 for exclusion of infections which have occurred more than 6 months back. This leaves a margin of safety of 3 months so as not to miss the rare but possible fetal transmission following periconceptional infection (4,24,25) . FIG.…”

Section: Discussionmentioning

confidence: 99%

Reliability of Immunoglobulin G Antitoxoplasma Avidity Test and Effects of Treatment on Avidity Indexes of Infants and Pregnant Women

Flori

Tardy

Patural

et al. 2004

Clin Vaccine Immunol

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The immunoglobulin G antitoxoplasma avidity test (Vidas; BioMérieux) is an immunoenzymatic test useful for excluding acute infection after the onset of pregnancy. The avidity index (AI) is the ratio of the signal in a test sample washed with urea, which disrupts low-avidity complexes, to that washed without urea. An AI of >0.3 is taken to mean that infection had occurred more than 4 months ago. The increase of the AI with time and the influence of the different treatments given to pregnant women and their newborns were evaluated. A total of 59 pregnant women (271 sera) and their 60 neonates (199 sera) were tested from 1998 to 2002. There were five groups of women based on the type and duration of treatment given. Thirteen pregnant women (group 1) did not receive any treatment, 15 (group 2), 11 (group 3), and 17 (group 4) women received treatment with spiramycin (9 MIU/day) for 0.5 to 2, 2.5 to 5, and 5.5 to 8 months, respectively, and the last 3 women (group 5) received tritherapy (pyrimethamine-sulfonamide and spiramycin alternatively) for 1.5 to 2.5 months. All of the maternal sera collected in the first 6 months had an AI of <0.30, with a mean of 0.07 (range, 0.01 to 0.21). The increase was slow (0.02/month), and there was no significant difference when comparisons were made between the treatment groups. Neonates with proven maternofetal transmission had an increasing AI, unlike those without transmission. However, long-term therapy with pyrimethamine-sulfonamide, as opposed to treatment with spiramycin alone, was found to slow down the progression of the AI. An AI of >0.2 is sufficient to exclude acute infection in pregnant women. In neonates, it is not of major use to diagnose congenital infection; however, it could be a good indicator of compliance and efficacy of treatment of infected infants.Toxoplasmosis, caused by Toxoplasma gondii, is widespread in humans and warm-blooded animals. Although usually asymptomatic in immunocompetent humans, toxoplasmosis may cause severe disorders in immunocompromised individuals and in pregnant women because of the high risk of transplacental transmission and the occurrence of abortion or multiple congenital lesions in the fetus (7, 9). In France, specific immunoglobulin G (IgG) and IgM antibody evaluation is mandatory in the first trimester of pregnancy. The presence of toxoplasma-specific IgM at the time of the first blood test is a cause for concern. In certain cases it could either be nonspecific IgM (8,10,[16][17]26) or residual IgM from a previous infection (8,12,16,20). In the remaining cases, it could of course be due to an acute infection. To confirm the latter, the presence of an associated elevated IgG level allows a complementary test to be done: the avidity test.The avidity test (Vidas; BioMérieux, Marcy l'Etoile, France) is of major interest when it is done during the first trimester of pregnancy. It permits dating (an avidity index [AI] of Ͼ0.3 means that infection occurred more than 4 months ago) and excludes infection that has occurred after the onset of...

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Section: Discussionmentioning

confidence: 99%

Reliability of Immunoglobulin G Antitoxoplasma Avidity Test and Effects of Treatment on Avidity Indexes of Infants and Pregnant Women

Flori

Tardy

Patural

et al. 2004

Clin Vaccine Immunol

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“…8 However, the risk of congenital transmission may exist not only in cases of seroconversion, but also in cases of suspected infection as detected by elevated mean titers of IgM and/or IgA and IgG. 2,10 Therefore, clinical and serological follow-up for all neonates of IgM-reagent pregnant women, even if they are asymptomatic, is recommended. 15,18 Brazil is a vast country, with marked differences in socioeconomic conditions and health care levels among its population.…”

Section: Introductionmentioning

confidence: 99%

Suspected acute toxoplasmosis in pregnant women

2007

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OBJECTIVE:To determine the prevalence of reagent serology for suspected acute toxoplasmosis in pregnant women and to describe clinical, laboratory and therapeutic profiles of mothers and their children. METHODS:A retrospective study was conducted with IgM-anti-Toxoplasma gondiireagent pregnant women and their children who attended the public health system in the state of Paraná, Southern Brazil, from January 2001 to December 2003. Information were obtained from clinical, laboratory (ELISA IgM/IgG) and ultrasonographic data and from interviews with the mothers. To test the homogeneity of the IgM indices in relation to the treatment used, the Pearson's Chi-square test was applied. Comparisons were considered significant at a 5% level. RESULTS:Two hundred and ninety (1.0%) cases of suspected IgM-reagent infection were documented, with a prevalence of 10.7 IgM-reagent women per 1,000 births. Prenatal care started within the first 12 weeks for 214/290; 146/204 were asymptomatic. Frequent complaints included headaches, visual disturbance and myalgia. Ultrasonography revealed abnormalities in 13 of 204 pregnancies. Chemoprophylaxis was administered to 112/227; a single ELISA test supported most decisions to begin treatment. Pregnant women with IgM indices =2.000 tended to be treated more often. Among exposed children, 44/208 were serologically followed up and all were IgGreagent, and three IgM-reagent cases showed clinical symptoms. CONCLUSIONS:The existence of pregnant women with laboratorially suspected acute toxoplasmosis who were not properly followed up, and of fetuses that were not adequately monitored, shows that basic aspects of the prenatal care are not being systematically observed. There is need of implementing a surveillance system of pregnant women and their children exposed to T. gondii. CONCLUSÕES: A existência de gestantes com suspeita laboratorial de toxoplasmose aguda não devidamente investigada e de conceptos sem monitoração adequada evidenciam que aspectos fundamentais da assistência pré-natal não estão sendo sistematicamente observados. Aponta-se a necessidade de implementar o sistema de vigilância para gestantes e crianças expostas ao T. gondii.28 Rev Saúde Pública 2007;41(1):27-34 Suspected acute toxoplasmosis in pregnancy Castilho-Pelloso MP et al Para testar a homogeneidade dos indices de IgM em relação ao tratamento usado, aplicou

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“…Thus, it is necessary to accomplish active seeking during all pregnancy for toxoplasmosis through serological tests. In negative cases, serology has to be repeated trimestrally up to one month after delivery (Foulon et al 1999a, Chemla et al 2002. If seroconversion occurs during gestational period, it is necessary to treat mothers to reduce transmission or sequelae in infants (Foulon et al 1999b).…”

Section: Discussionmentioning

confidence: 99%

A comparative study of congenital toxoplasmosis between public and private hospitals from Uberlândia, MG, Brazil

Segundo

Silva

Mineo

et al. 2004

Mem. Inst. Oswaldo Cruz

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Preconception Seroconversion and Maternal Seronegativity at Delivery Do Not Rule Out the Risk of Congenital Toxoplasmosis

Cited by 18 publications

References 13 publications

Reliability of Immunoglobulin G Antitoxoplasma Avidity Test and Effects of Treatment on Avidity Indexes of Infants and Pregnant Women

Reliability of Immunoglobulin G Antitoxoplasma Avidity Test and Effects of Treatment on Avidity Indexes of Infants and Pregnant Women

Suspected acute toxoplasmosis in pregnant women

A comparative study of congenital toxoplasmosis between public and private hospitals from Uberlândia, MG, Brazil

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