TORCH infections represent a group of vertically transmitted infections that can have significant impacts on both maternal and foetal health. The acronym TORCH stands for several infectious agents: Toxoplasma gondii, Others: Treponema Pallidum, Varicella Zoster Virus (VZV) and Parvovirus, Rubella virus, Cytomegalovirus (CMV), and Herpes Simplex Virus (HSV). In this blog, we'll delve into each of these infections, highlighting their main characteristics, symptoms, transmission modes, recovery periods and diagnosis methods.

Toxoplasma gondii

Toxoplasma gondii is a protozoan parasite responsible for toxoplasmosis. Transmission occurs through the consumption of undercooked contaminated meat, contact with cat faeces and from an infected mother to her foetus during pregnancy. The initial symptoms of toxoplasmosis are similar to those of a mild cold with myalgia and lymphadenopathy as the main symptoms.

With 60-80% of women lacking immunity, the primary concern for Toxoplasma gondii infection is transplacental transmission to the foetus. Severe damage is most likely during the first trimester, though transmission is more frequent in the third trimester. In fact, toxoplasmosis during pregnancy can lead to spontaneous abortions, low birth weight, hepatomegaly, and severe brain and eye damage, contributing to lasting developmental disorders.

Routine monitoring and preventive strategies, such as avoiding contact with cat faeces and ensuring proper meat cooking, are essential in keeping both the mother and foetus safe.

Others

The "Others" category introduces additional pathogens, including Treponema pallidum – responsible for Syphilis – VZV  and Parvovirus B19. This broadens the pathogenic landscape of TORCH infections, prompting ongoing research and surveillance efforts to manage potential threats.
The rise of these new infections during pregnancy emphasises the importance of prenatal care.

Rubella

Rubella, also known as German measles, is a viral infection caused by the Rubella virus. Symptoms include headache, lymph node swelling, and a characteristic rash also known as spotted exanthema, that usually lasts around three days. It can also lead to more serious complications such as arthritis, myocarditis, neuritis, otitis,and encephalitis. Transmission of rubella occurs through aerosols and droplet infection, rendering individuals contagious even during the 2–3-week incubation period.

Notably, 10-20% of women of child-bearing age lack immunity against rubella, leading to concerns regarding transplacental transmission. This transmission can result in severe forms of rubella embryopathy, posing risks to foetal development. In fact, in numerous countries acute rubella infections have been associated with the termination of early pregnancies. The complex interplay of contagiousness during the incubation period and the potential for severe complications highlights the importance of immunisation and rigorous prenatal care to maintain both maternal and foetal wellbeing.

Cytomegalovirus (CMV)

CMV belongs to the herpesvirus family and causes symptoms such as fever, fatigue and muscle aches. In healthy individuals, the infection is often mild or asymptomatic; however, severe complications can arise in newborns or immunocompromised individuals.

In healthy individuals, CMV infection is often asymptomatic or presents with mild, flu-like symptoms such as fatigue, fever, and cough. However, in newborns or immunocompromised individuals, severe and potentially fatal complications can arise, affecting organs such as the lungs, liver and central nervous system.

CMV has multiple transmission routes including person-to-person contact via saliva, sperm, blood, breast milk and transplacental transmission. Alarmingly, 40-60% of women in childbearing age are not immunised to CMV, heightening the risk of transmission during pregnancy.

Women can transmit the virus to the baby either before birth (congenital) or during/shortly after birth (perinatal). Congenital CMV is the most frequent intrauterine infection, underscoring the significance of monitoring and preventive measures during pregnancy. Primary CMV infection during pregnancy can have severe potential complications. Notably, children can secrete the virus for up to three years after congenital infection, contributing to the ongoing transmission risks.

Herpes Simplex Virus (HSV)

With a substantial prevalence globally, HSV poses a widespread health concern. Many individuals infected with HSV can remain asymptomatic, contributing to ongoing transmission risks. Vulnerability is accentuated during periods of active outbreaks, where the virus sheds, and precautionary measures become crucial.

HSV manifests with characteristic symptoms including painful sores, flu-like symptoms and itching. Recurrent outbreaks are common and often triggered by factors such as stress, illness or immunosuppression. While HSV-1 typically causes oral herpes, HSV-2 is primarily associated with genital herpes.

Pregnant women with genital herpes can transmit the virus to the baby during childbirth, leading to neonatal herpes. This transmission, if not promptly addressed, can result in severe health consequences, including neurological damage and even death.

Antiviral medications play a crucial role in managing symptoms and reducing the frequency of outbreaks. Additionally, preventive measures such as safe sexual practices, particularly during active outbreaks, are essential in limiting transmission risks.

Diagnostic Methods

The analysis of antibodies against TORCH parameters is a crucial component of comprehensive prenatal, perinatal and postnatal care. These tests play a pivotal role in establishing the immune status of the mother and assessing potential risks to an ongoing pregnancy. Typically conducted during the first trimester of pregnancy, TORCH tests allow the differentiation between acute primary infections, past infections or reactivations. This offers valuable insights into the trajectory of the pregnancy and in cases where infection is suspected these tests can also be performed to newborns. The primary objective of investigating antibodies against TORCH pathogens is to ascertain the mother's immune status, enabling healthcare professionals to identify and differentiate infections. Early diagnosis is essential, as it allows for timely interventions and effective treatments, potentially mitigating the risk of birth defects or foetal loss. EUROLINE Anti-TO.R.C.H Profile (IgG, IgM) provides an extensive profile for the detection of IgG antibodies against pregnancy-relevant infectious agents.This comprehensive profile allows for the determination of immune status, providing a foundation for the proactive management of potential risks during gestation. The assessment includes a thorough examination of IgG and IgM antibodies, enabling a nuanced understanding of the individual's susceptibility to TORCH infections and their potential implications for pregnancy.

In instances where a primary infection is suspected, the measurement of IgM antibodies becomes particularly pertinent. A positive IgM result prompts further investigation, ensuring a more accurate diagnosis and assessment of the infection's severity.

Molecular detection with EUROArray STI also allows a wider and more accurate pathogen detection. This panel further complements the reliability and accuracy of immune status assessment and risk evaluation during pregnancy. Moreover, the EUROArray STI panel goes beyond TORCH diagnostics, incorporating multiplex detection of 11 sexually transmitted pathogens. This includes Chlamydia trachomatis, Treponema pallidum, HSV-1 and HSV-2, among others. The inclusion of sexually transmitted pathogens extends the diagnostic scope, potentially contributing to the prevention of infertility and abortion associated with these infections. The automated evaluation using the EUROArray Scan Software ensures consistency in interpreting test results, adding an extra layer of reliability to the diagnostic process.

Conclusion

In navigating the intricacies of TORCH infections, an accurate and proactive stance in prenatal care is crucial. Routine screenings, preventive strategies and early interventions collectively help in mitigating the diverse risks posed by these pathogens. EUROIMMUN offers a variety of diagnostic assays and methods for the investigation of TORCH diagnostics, both for individual pathogens or as multiplex profile.