Anti-Toxoplasma gondii IgG avidity testing is necessary for diagnosis of acute toxoplasmosis

Abdullahi, Idris Nasir; Shehu, Muhammad Sagir; Adekola, Hafeez Aderinsayo

doi:10.1016/j.jtumed.2016.11.004

Cited by 4 publications

(5 citation statements)

References 9 publications

(13 reference statements)

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“…Our results revealed the presence of T. gondii DNA in 47 (30.9%) of HIV-infected patients, including 34 (22.3%) of seropositive infections, which is comparable to the studies of Rostami et al and Colombo [12,19]. However, in 8.6% of cases, none of the antibodies were detected, which may indicate either a low antibody level (below the sensitivity limit of detection) or a seronegative course of infection [18] and justify the use of molecular testing for detecting T. gondii DNA. Sequencing of positive samples revealed that all of them were closely related (<99%) to isolates of genotype II T. gondii, which is the most common in Europe [5,39,47].…”

Section: Discussionsupporting

confidence: 88%

“…The routine diagnostic of toxoplasmosis is based on serologic tests (detection IgM/ IgA/IgG and assessment of IgG avidity index); however, they may have a low predictive value, especially in patients with HIV-related severe immune deficits (atypical serologic window or a seronegative course of infection) [8,16]. Available research and diagnostic studies on T. gondii infection are mainly focused on assessing the IgG avidity index, in the context of vertical infection, rather than in immunocompromised host or blood donors [16][17][18].…”

Section: Introductionmentioning

confidence: 99%

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Seronegative Infection with Toxoplasma gondii in Asymptomatic Human Immunodeficiency Virus Type 1 (HIV-1)-Infected Patients and in Blood Donors

Bednarska

Cortés

Glamkowska-Sady

et al. 2022

JCM

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Background: Toxoplasmosis is a common opportunistic infection in AIDS patients. The routine diagnostics is based on serologic testing and IgG avidity index, but it may have limited utility in immunodeficient patients; thus, it is recommendable to detect T. gondii DNA in subjects with advanced HIV disease. The results of the studies published so far focused on patients with clinical symptoms of toxoplasmosis. Our study encompassed a group of HIV-infected subjects on cART therapy, without immunological disturbances and clinical symptoms of T. gondii infection. Methods: The study was retrospective, and samples were collected between 2013 and 2016. We evaluate the prevalence of serological (IgM, IgG, and avidity IgG) and molecular (DNA) T. gondii infection markers in asymptomatic HIV-infected patients and the control group using serologic (ELISA) and quantitative (real-time PCR) molecular testing. Results: Of 152 HIV-infected in routine follow-up tested for T. gondii IgM and IgG, 6 (3.9%) and 50 (32.9%) were positive, respectively. Of 168 serum samples from blood donors, 1 (0.6%) and 49 (29.2%) were IgM+ and IgG+ positive, respectively. IgM seroprevalence in HIV-infected patients was significantly higher than in blood donors. T. gondii DNA (genotype II) was identified in 47 (30.9%) HIV-infected patients, with 13 (8.6%) IgM−IgG− samples. In blood donors, T. gondii DNA was present in 15 (8.9%) IgM−IgG−. Conclusions: In both groups, T. gondii DNA was detectable in seronegative subjects, implying the need to supplement the routine serological testing via the molecular method. It can help the accurate monitoring of the reactivation of infection in asymptomatic HIV-infected persons, and the quick introduction of specific therapy, in blood donors, would be of high importance for safe blood donations.

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Section: Discussionsupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Seronegative Infection with Toxoplasma gondii in Asymptomatic Human Immunodeficiency Virus Type 1 (HIV-1)-Infected Patients and in Blood Donors

Bednarska

Cortés

Glamkowska-Sady

et al. 2022

JCM

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“…A detecção específica de IgM para toxoplasmose é o mais utilizado para o diagnóstico de infecção aguda. Entretanto, diversos autores têm demonstrado que apenas um resultado de IgM positivo não é confiável para o diagnóstico de infecção aguda, pois podem persistir por um ano ou mais após a infecção, sugerindo-se a necessidade de exames sorológicos sequenciais, da utilização do teste de avidez de IgG, IgA e de métodos diagnósticos para identificar a infecção fetal, quando tratar-se de gestantes com risco de transmissão transplacentária 11,24 . No entanto, o laboratório no qual os dados foram coletados não realizava pesquisa de IgA e nem de avidez de IgG.…”

Section: Discussionunclassified

“…Devido à dificuldade em diferenciar infecções agudas de infecções crônicas, deve ser realizado o teste de avidez de IgG, que é um teste importante para rastrear qualquer aumento potencial nos níveis de IgG, auxiliando na determinação da fase aguda e crônica da doença, pois é um método extremamente confiável no diagnóstico da toxoplasmose aguda. Sugere-se que a baixa avidez de IgG resultam em infecção aguda, enquanto a alta avidez de IgG confirma infecção crônica ou reativada [10][11] .…”

Section: Introductionunclassified

Perfil sorológico para toxoplasmose em mulheres na idade reprodutiva, Santa Cruz, Rio Grande do Norte

Melo

Oliveira

Barbosa³

2022

Rev. Saúde Col. UEFS

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A toxoplasmose é uma zoonose causada pelo Toxoplasma gondii, um protozoário com ampla distribuição mundial. Essa infecção apresenta maior impacto em indivíduos imunocomprometidos e nas infecções congênitas. Objetivou-se avaliar o perfil sorológico para toxoplasmose de mulheres em idade reprodutiva (15-49 anos) atendidas em uma maternidade-escola de Santa Cruz, Rio Grande do Norte (RN). Foi realizado um estudo descritivo, retrospectivo e quantitativo em que se analisou os laudos de 274 mulheres, do período de janeiro a maio de 2018. As variáveis estudadas foram: resultado das sorologias IgG e IgM anti-Toxoplasma, idade, zona e bairro de residência e método(s) de diagnóstico(s) utilizado(s). Dos 274 laudos, 40,1% apresentaram sorologia reagente para IgG anti-T. gondii. Apresentaram IgM anti-T.gondii reagente, 0,7%, enquanto 47,8% eram suscetíveis à toxoplasmose. Dos 241 laudos com sorologias conclusivas (soropositivas ou suscetíveis), as mulheres na faixa etária 31-42 anos apresentaram associação estatisticamente significativa com soropositividade e uma ocorrência 1,4 vezes maior que as de 15-30 anos (p = 0,014; RP=1,420, IC = 1,086-1,859). O maior percentual de soropositivas foi na zona urbana (72,2%) e bairro Paraíso (43,2%) da cidade de Santa Cruz. Desse modo, verificou-se que há necessidade de programas de promoção a saúde e melhorias sanitárias e ambientais para as mulheres da região.

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“…Walle et al found anti- T.gondii IgM in 10.7% of HIV individuals (28). A study from India detected 6% anti- T. gondii IgM in HIV cases (29).…”

Section: Discussionmentioning

confidence: 99%

Prevalence of Toxoplasma gondii Antibodies and DNA in Iranian HIV Patients

et al. 2018

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Background & Objective: Toxoplasma gondii infection has public health importance and can lead to serious diseases in immunosuppressed patients, such as HIV cases. Appropriate control of T. gondii infection in HIV patients requires information about the prevalence of T. gondii antibodies and DNA in different population. In this study, we aimed to determine the prevalence of Toxoplasma gondii antibodies and DNA in HIV patients in Tehran, Iran. Methods: A total of 149 HIV patients from the Iranian Research Center for HIV/AIDS, Tehran, Iran were enrolled in the study. Anti-Toxoplasma IgG and IgM were detected by ELISA and T. gondii DNA was evaluated by PCR and quantita- tive real-time PCR. IgG positive samples were also assessed for their avidity. Results: Anti-Toxoplasma IgG and IgM were positive in 46.3% and 2.7% of cases respectively. 92.7% of our patients showed past infection and 4.3% revealed recently acquired toxoplasmosis based on their IgG avidity test. T. gondii DNA was not detected by PCR but real-time PCR results showed DNA in 4.7% of total patients and 13.1% of the IgG seropositive cases. Conclusion: Our findings indicated that latent toxoplasmosis was relatively prevalent in our study population, but new T. gondii infection had low prevalence. Almost half of our patients were IgG negative and at risk of acquiring toxoplasma infection. Low copy numbers of DNA were detected in 4.7% of the cases without any clinical manifestation. Therefore, detection and monitoring of anti-Toxoplasma antibodies and DNA in HIV patients is substantial to estimate the risk of reactivation and new infection.

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Anti-Toxoplasma gondii IgG avidity testing is necessary for diagnosis of acute toxoplasmosis

Cited by 4 publications

References 9 publications

Seronegative Infection with Toxoplasma gondii in Asymptomatic Human Immunodeficiency Virus Type 1 (HIV-1)-Infected Patients and in Blood Donors

Seronegative Infection with Toxoplasma gondii in Asymptomatic Human Immunodeficiency Virus Type 1 (HIV-1)-Infected Patients and in Blood Donors

Perfil sorológico para toxoplasmose em mulheres na idade reprodutiva, Santa Cruz, Rio Grande do Norte

Prevalence of Toxoplasma gondii Antibodies and DNA in Iranian HIV Patients

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