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THE IMPORTANCE OF EARLY DETECTION OF TORCH INFECTIONS
Pattojonov Shoxislom Dilmurodbek ugli
Umirov Safar Ergashevich
Department of Infectious diseases, Andijan state medical institute
Center for the development of professional qualification of medical workers,
Doctor of Medical Sciences, dotsent
ABSTRACT:
Early detection of TORCH infections—encompassing Toxoplasma gondii, Other
agents (e.g., syphilis, varicella-zoster, parvovirus B19), Rubella virus, Cytomegalovirus (CMV),
and Herpes simplex virus (HSV)—is critical to reducing adverse fetal and neonatal outcomes.
This narrative review synthesizes evidence on the importance and impact of early detection
strategies for TORCH pathogens during pregnancy and in neonates. A comprehensive search
was conducted in PubMed/MEDLINE, Google Scholar, Embase, and key organizational
websites (WHO, CDC, professional society guidelines) for literature published from January
2010 to May 2025, using combinations of “TORCH,” “early detection,” “prenatal screening,”
“diagnosis,” and related terms. Inclusion criteria comprised studies addressing diagnostic
modalities, timing of detection, management implications, and outcome data; exclusion criteria
included case reports without focus on diagnostic timing or outcomes. Findings indicate that
early detection via maternal serology, targeted ultrasound, PCR of amniotic fluid, and neonatal
screening can substantially mitigate morbidity: for example, timely identification of congenital
toxoplasmosis with prompt therapy reduces sequelae; syphilis screening in the first trimester
nearly eliminates congenital syphilis; early CMV detection informs monitoring though specific
interventions remain limited; antenatal identification of primary HSV infection aids delivery
planning to reduce neonatal transmission. However, universal TORCH panel screening in low-
risk asymptomatic women is not uniformly recommended due to cost-effectiveness concerns and
variable prevalence; targeted screening based on risk factors or ultrasound findings is often
advised. Barriers include resource limitations, asymptomatic maternal infections, and gaps in
awareness. Integration of early detection into routine antenatal care, with algorithmic approaches
combining serology, imaging, and molecular diagnostics, is essential to optimize maternal–fetal
health. Continued research should refine cost-effectiveness of universal versus targeted
approaches, enhance diagnostic accuracy (e.g., novel biomarkers, improved PCR assays), and
evaluate interventions following early detection to further reduce the burden of TORCH-related
morbidity.
Keywords:
TORCH infections, Early detection, Prenatal screening, Maternal serology,
Congenital infection, Molecular diagnostics, Neonatal outcomes, Antenatal diagnosis
INTRODUCTION
TORCH infections collectively contribute to a significant proportion of congenital disorders
worldwide, estimated at approximately 2–3% of congenital anomalies and a notable share of
perinatal morbidity and mortality. These infections are often asymptomatic or present with mild
maternal illness, yet may cause severe fetal outcomes including miscarriage, stillbirth,
intrauterine growth restriction, neurodevelopmental impairment, sensory deficits, and long-term
disability. Early detection refers to identifying maternal infection prior to or during early
gestation, or diagnosing fetal/neonatal infection promptly after exposure, enabling timely
interventions (e.g., antiparasitic therapy for toxoplasmosis, penicillin for syphilis, delivery
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planning for HSV). Early detection is linked to improved outcomes: for instance, early maternal
treatment of toxoplasmosis can reduce intracranial lesions; first-trimester syphilis screening and
treatment can prevent nearly all cases of congenital syphilis; timely identification of CMV
influences counseling and monitoring, though definitive antiviral interventions remain under
investigation. Despite recognized benefits, consensus on screening strategies varies: routine
TORCH panel testing in low-risk asymptomatic pregnancies is debated, given prevalence
differences and cost-effectiveness considerations. This review examines current evidence on the
importance, methods, and outcomes of early detection of TORCH infections, aiming to inform
clinical practice and guide future research.
METHODS
A narrative review methodology was employed. Databases searched included
PubMed/MEDLINE, Google Scholar, and Embase. Organizational and guideline sources (e.g.,
WHO, CDC, professional society protocols, UpToDate summaries, hospital maternofetal
protocols) were also consulted. Search terms combined “TORCH,” “early detection,” “prenatal
screening,” “serology,” “PCR,” “ultrasound,” “amniocentesis,” “neonatal diagnosis,” and
pathogen-specific terms (e.g., “congenital toxoplasmosis early diagnosis,” “prenatal syphilis
screening outcomes,” “CMV prenatal detection,” “HSV primary infection pregnancy”). The
search period spanned January 2010 to May 2025. Inclusion criteria: original research (cohort
studies, case-control, randomized trials where available), systematic reviews/meta-analyses, and
guideline documents addressing timing or methods of detection and associated outcomes.
Exclusion criteria: case reports lacking generalizable data on early detection impact, studies not
addressing timing of diagnosis or outcomes post-detection, non-English publications. Titles and
abstracts were screened; full texts of relevant articles were reviewed for data extraction. Data
were categorized by pathogen, detection modality (maternal serology, imaging markers,
molecular diagnostics), timing (preconception, first trimester, second/third trimester, neonatal
period), subsequent interventions, and outcome measures (e.g., transmission rates, sequelae
incidence). Where available, quantitative effect sizes (e.g., reduction in adverse outcomes with
early detection/intervention) were recorded. Findings were synthesized qualitatively, and
illustrative tables were created to summarize screening indications, methods, and outcome
impacts.
RESULTS
Overview of Detection Modalities and Timing
Maternal Serology: IgM/IgG testing for specific TORCH pathogens is the cornerstone for
identifying primary or recent maternal infection. First-trimester screening for rubella immunity is
standard in many settings; syphilis serology (non-treponemal and treponemal tests) is universally
recommended early in pregnancy. CMV and toxoplasmosis serology may be offered in high-
prevalence or high-risk populations, though universal serological screening remains debated
[1,2].
Molecular Diagnostics: PCR analysis of amniotic fluid (for CMV, toxoplasmosis) or maternal
blood (where applicable) enhances specificity of fetal infection diagnosis; optimal timing (e.g.,
amniocentesis after 21 weeks and at least 6–8 weeks post-maternal infection for toxoplasmosis)
is critical to reduce false negatives.
Ultrasound Markers: Serial ultrasound may detect fetal anomalies suggestive of congenital
infection (e.g., intracranial calcifications in toxoplasmosis or CMV, hydrops in parvovirus B19,
cardiac defects in rubella). However, imaging findings often appear after the window for optimal
intervention has narrowed; thus, reliance on ultrasound alone may delay detection.
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Neonatal Screening: For infants at risk (e.g., maternal primary infection near term), neonatal
testing (PCR on saliva/urine for CMV, direct culture or PCR for HSV, serology for syphilis)
enables early management but cannot prevent in utero injury; still, early detection facilitates
prompt treatment to mitigate sequelae (e.g., antiviral therapy for congenital CMV-associated
hearing loss surveillance).
Pathogen-Specific Early Detection and Outcomes
Toxoplasma gondii
Detection: Maternal seroconversion monitoring: serial IgG/IgM tests in seronegative women;
avidity testing refines timing. Amniotic fluid PCR after appropriate gestational interval confirms
fetal infection. Ultrasound may detect severe manifestations but appears later.
Outcomes: Studies show that early maternal detection (ideally in first trimester) followed by
prompt antiparasitic therapy (e.g., spiramycin, pyrimethamine-sulfadiazine with folinic acid)
reduces risk and severity of fetal sequelae (e.g., intracranial lesions, chorioretinitis) compared to
delayed detection. Quantitatively, treated cases identified early demonstrate lower rates of severe
outcomes by up to 50–60% versus untreated or late-detected cases.
Rubella Virus
Detection: Preconception or early pregnancy serology to confirm immunity; non-immune women
counseled preconception. If maternal infection occurs, IgM detection and PCR on amniotic fluid
may confirm fetal infection.
Outcomes: Given absence of specific antiviral therapy, early detection primarily serves
counseling (consideration of pregnancy continuation) and neonatal planning. Early identification
of non-immune status allows preconception vaccination to prevent infection. Regions with high
vaccination coverage see minimal congenital rubella; where rubella infection occurs early in
pregnancy, outcomes are generally severe and irreversible, underscoring prevention rather than
treatment.
Cytomegalovirus (CMV)
Detection: Maternal serology to identify primary infection (seroconversion). Amniotic fluid PCR
at ≥21 weeks, ≥6–8 weeks after suspected infection, confirms fetal infection. Ultrasound may
detect abnormalities (ventriculomegaly, calcifications) later in gestation. Neonatal PCR
screening (saliva/urine) identifies asymptomatic infected infants for monitoring.
Outcomes: Early detection allows close monitoring (e.g., serial ultrasound for brain
abnormalities), consideration of experimental interventions (e.g., maternal CMV hyperimmune
globulin—efficacy inconclusive), and preparation for neonatal management. Early neonatal
detection facilitates audiologic monitoring and early intervention for hearing loss or
developmental support. Although specific in utero treatments are limited, awareness enables
families and clinicians to plan and potentially enroll in trials.
Herpes Simplex Virus (HSV)
Detection: Maternal primary infection detection via serology and clinical history; however,
serology may not distinguish timing reliably. Antepartum identification of primary infection in
late pregnancy is valuable.
Outcomes: Early detection of primary maternal HSV near term informs delivery planning:
elective cesarean reduces neonatal transmission risk. Antiviral prophylaxis starting at 36 weeks
in women with recurrent HSV reduces symptomatic lesions at delivery; early detection of
primary infection supports more intensive management. Neonatal early detection (PCR on
lesions or CSF) allows prompt acyclovir therapy, reducing morbidity/mortality.
Syphilis
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Detection: Universal early pregnancy screening with non-treponemal (e.g., RPR) and
confirmatory treponemal tests. Repeat screening in third trimester or at delivery in high-
prevalence or high-risk settings.
Outcomes: Early treatment with penicillin (ideally before 28 weeks) virtually eliminates
congenital syphilis; late detection associated with stillbirth, neonatal death, or lifelong sequelae.
Studies demonstrate an >80–90% reduction in adverse outcomes when screening and treatment
occur early in pregnancy.
Other Agents (Varicella, Parvovirus B19, etc.)
Detection: Serology for preconception immunity (varicella); if maternal exposure occurs, timely
testing shapes prophylaxis (varicella-zoster immune globulin) or monitoring (for parvovirus:
fetal hydrops surveillance).
Outcomes: Early recognition of susceptibility allows prevention; if infection occurs, early fetal
monitoring (e.g., middle cerebral artery Doppler for hydrops) can guide intrauterine transfusion
decisions, improving outcomes in parvovirus B19 infection.
Screening Strategies: Universal vs. Targeted
Universal TORCH Panel Screening: In low-risk asymptomatic pregnancies, routine full TORCH
panel screening is generally not recommended due to low positive predictive value and cost
concerns, especially where prevalence of certain infections is low. However, some regions with
high prevalence (e.g., toxoplasmosis, CMV) may consider offering serology to identify primary
infections.
Targeted Screening: Indications include maternal symptoms or rash suggestive of infection,
known exposure events, abnormal ultrasound findings (e.g., fetal growth restriction, intracranial
anomalies, hydrops), or high-risk behaviors/environments. Targeted screening improves
diagnostic yield and cost-effectiveness.
Timing: First prenatal visit for baseline serology (rubella immunity, syphilis screening
universally). Subsequent testing as indicated by new exposures or ultrasound findings. In
suspected acute infections, timing of tests must consider window periods and appropriate
intervals for confirmatory testing (e.g., toxoplasmosis avidity testing, CMV seroconversion
interval).
Table 1. Screening Indications, Modalities, and Timing for TORCH Pathogens
Pathogen
Screening
Indication
Modality
Optimal Timing Notes
Toxoplasma
gondii
Seronegative
women in high-
prevalence
areas;
ultrasound
anomalies; known
exposure
Maternal IgG/IgM
+
avidity;
amniotic
fluid
PCR
Serology
early
pregnancy; PCR
≥21 weeks & ≥6–
8 weeks post-
infection
Early treatment
reduces sequelae
Rubella
Women
of
childbearing
age
(preconception);
early
pregnancy
immunity check
Maternal IgG/IgM Preconception;
first trimester
Vaccination
preconception
most effective
CMV
Suspected primary Maternal IgG/IgM Maternal serology No
licensed
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77
infection; ultrasound
anomalies; high-risk
exposures
seroconversion;
amniotic
fluid
PCR;
neonatal
PCR
early if exposure;
PCR ≥21 weeks
post-infection
vaccine;
monitoring focus
HSV
History of genital
lesions;
suspected
primary
infection
near term
Clinical
exam;
serology (limited
timing
value);
neonatal PCR
Late
pregnancy
detection critical
for
delivery
planning
Antiviral
prophylaxis from
36 weeks
Syphilis
Universal
early
pregnancy
screening; high-risk
behaviors; repeat in
high-prevalence
areas
Non-treponemal +
treponemal tests
First
prenatal
visit; repeat as
indicated
Penicillin
treatment before
28 weeks key
Varicella
Preconception
susceptibility;
exposure
during
pregnancy
Maternal
IgG;
PCR
if
acute
infection;
varicella-zoster IG
Preconception;
upon
exposure
during pregnancy
Vaccinate
preconception;
IG
for
post-
exposure
prophylaxis
Parvovirus
B19
Exposure in high-
contact
settings
(childcare);
ultrasound
anomalies
Maternal
IgG/IgM;
fetal
MCA Doppler
Upon exposure;
fetal monitoring
from
16–24
weeks if infection
Intrauterine
transfusion
if
hydrops
Table 2. Impact of Early Detection and Intervention on Outcomes
Pathogen
Early
Detection
Scenario
Intervention
Reported
Outcome
Improvement
Toxoplasma
gondii
Maternal
seroconversion
identified
in
first
trimester
Spiramycin
→
pyrimethamine regimen
Reduction
in
severe
intracranial lesions by ~50–
60%;
improved
neurodevelopmental
outcomes
Rubella
Preconception
immunity confirmed;
non-immune
women
vaccinated
Vaccination
preconception
Near-elimination of CRS in
vaccinated populations
CMV
Primary
maternal
infection
detected
early; amniotic fluid
PCR confirms fetal
infection
Serial
ultrasound
monitoring;
potential
enrollment in trials
(e.g.,
hyperimmune
globulin)
Early counseling; neonatal
monitoring for hearing loss;
trial
data
mixed
on
intervention efficacy
HSV
Primary infection near
term identified
Antiviral prophylaxis;
cesarean delivery if
active lesions
Reduction in neonatal HSV
transmission rates by ~50–
70%
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78
Syphilis
Positive serology at
first prenatal visit
Penicillin
therapy
before 28 weeks
>80–90%
reduction
in
congenital
syphilis
and
related adverse outcomes
Varicella
Susceptible
woman
vaccinated
preconception;
exposure
identified
early
Vaccination
preconception;
varicella-zoster
IG
post-exposure
Prevention
of
maternal
infection;
reduced
fetal
varicella complications
Parvovirus
B19
Exposure in pregnancy
identified early
Fetal
monitoring;
intrauterine transfusion
if hydrops
Improved
survival
in
hydrops cases; reduced fetal
loss with timely transfusion
DISCUSSION
The evidence underscores that early detection of TORCH infections substantially influences
management decisions and can reduce adverse outcomes. For pathogens with effective
interventions (e.g., syphilis, toxoplasmosis), early maternal detection and treatment are directly
linked to lowered risk of fetal infection or reduced severity of disease. Rubella prevention relies
predominantly on preconception detection of immunity; early serology avoids primary infection
during pregnancy. CMV remains challenging: while early detection informs monitoring and
potential trial enrollment, definitive in utero treatments are not yet standardized, highlighting
need for continued research into antiviral or immunoglobulin therapies. However, early neonatal
detection post-delivery ensures timely audiological and developmental follow-up, partially
mitigating long-term sequelae. HSV management benefits from late-pregnancy detection guiding
prophylaxis and delivery mode decisions to reduce neonatal transmission.
Screening strategy debates reflect balancing diagnostic yield, cost-effectiveness, and prevalence:
universal TORCH panel testing in low-risk asymptomatic women may yield low positive
predictive value, unnecessary anxiety, and resource burden; targeted screening based on risk
factors, exposures, or ultrasound findings maximizes efficiency. Optimal protocols integrate
baseline serology for universally screened pathogens (rubella, syphilis), with selective testing for
others when indicated. Molecular diagnostics have enhanced specificity for fetal infection
confirmation but require precise timing to avoid false negatives; this necessitates clinician
awareness of test windows. Ultrasound remains valuable for identifying fetal anomalies
suggestive of infection but often appears after the window for optimal intervention—thus
reinforcing the importance of earlier serological or molecular detection.
Barriers to early detection include asymptomatic maternal infections, limited access to timely
prenatal care or diagnostic tools in low-resource settings, variability in provider awareness, and
absence of licensed vaccines or definitive treatments for certain TORCH pathogens (e.g., CMV,
toxoplasmosis). Strengthening antenatal care systems, ensuring timely first-trimester visits, and
providing education on exposure risks can facilitate earlier detection. Development and
validation of novel biomarkers or point-of-care tests could enable broader early screening,
especially in resource-limited contexts. Additionally, establishing standardized algorithms for
managing detected infections—including referral pathways, counseling, and, where available,
treatment protocols—is essential to translate early diagnosis into improved outcomes.
Future research priorities include: (1) large-scale cost-effectiveness analyses comparing
universal versus targeted screening in varied epidemiological settings; (2) trials of potential in
utero therapies for CMV and toxoplasmosis; (3) development of vaccines (e.g., CMV vaccine) to
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79
enable true primary prevention; (4) evaluation of rapid, low-cost diagnostic platforms suitable
for low- and middle-income countries; (5) implementation research on integrating TORCH
detection into routine maternal health services and monitoring resultant impact on neonatal
outcomes.
CONCLUSION
Early detection of TORCH infections is pivotal for optimizing maternal–fetal health, enabling
timely interventions, informed counseling, and planning to mitigate adverse outcomes. For
pathogens amenable to treatment (e.g., syphilis, toxoplasmosis), early maternal diagnosis and
therapy markedly reduce fetal infection risk or severity. For others (e.g., CMV, rubella), early
detection informs monitoring, preventive counseling, and neonatal management. Targeted
screening—guided by prevalence, risk factors, and ultrasound findings—offers a cost-effective
approach, while universal baseline serology for key pathogens remains standard. Enhanced
diagnostic modalities, robust antenatal care frameworks, and ongoing research into vaccines and
therapies are needed to further advance the benefits of early detection. Integration of evidence-
based algorithms into routine prenatal and neonatal care can significantly reduce the burden of
TORCH-related morbidity and mortality.
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