Effectiveness of the standardized strategy for prevention of mother-to-child transmission of human immunodeficiency virus in Ecuador

Abstract

BACKGROUND

Mother-to-child transmission of human immunodeficiency virus (HIV) remains a significant public health challenge in Latin America. In Ecuador, national reports indicate that vertical transmission rates continue to exceed the elimination threshold, underscoring the need for consistent implementation of standardized prevention strategies.

AIM

To evaluate the effectiveness of Ecuador’s standardized strategy for prevention of mother-to-child transmission of HIV during 2017-2023.

METHODS

This retrospective study analyzed clinical records and notification forms of all HIV-exposed infants enrolled in the institutional prevention program. Data included sex, maternal risk classification, neonatal prophylaxis, virologic follow-up, and serologic testing at 18 months. Infants were categorized as HIV-positive, HIV-negative, seroreverters, under evaluation, or lost to follow-up. The vertical transmission incidence was calculated among infants with complete diagnostic evaluation. All procedures adhered to institutional and national ethical standards for the use of anonymized clinical data.

RESULTS

In total, 320 HIV-exposed infants were included. Two infants were diagnosed with HIV infection, resulting in a vertical transmission rate of 0.65% (2/309; 95% confidence interval: 0.18%-2.35%) after excluding infants lost to follow-up. Most infants (91.3%) were confirmed HIV-negative before 6 months of age, and 265 achieved seroreversion at 18 months. The observed transmission rate was substantially lower than the national estimate of 2.07%, reflecting the effectiveness of the standardized prevention strategy.

CONCLUSION

The standardized strategy for prevention of mother-to-child transmission achieved a very low vertical HIV transmission rate, and underscoring the importance of consistent maternal treatment and neonatal prophylaxis.

Key Words: Human immunodeficiency virus; Mother-to-child transmission; Neonatal prophylaxis; Antiretroviral therapy; Ecuador

Core Tip: This study shows that a rigorously implemented, standardized national strategy for prevention of mother-to-child transmission of human immunodeficiency virus can achieve a vertical transmission rate of 0.65% in a real-world Ecuadorian setting. The findings highlight the importance of early maternal diagnosis, consistent antiretroviral therapy, and coordinated maternal-infant follow-up to sustain progress toward national elimination goals.

INTRODUCTION

Prevention of mother-to-child transmission (PMTCT) of human immunodeficiency virus (HIV) refers to a set of interventions designed to prevent mother-to-child, or vertical, transmission and represents one of the most significant public health achievements of the past 3 decades. In the absence of medical interventions, transmission rates range from 15% to 45% and are influenced by factors such as breastfeeding duration. However, the implementation of robust clinical protocols has demonstrated that this risk can be reduced to less than 1% in settings with comprehensive prenatal care[1,2].

Since recognition of the risk of mother-to-child transmission in the early 1980s, PMTCT approaches have progressed from basic recommendations—such as avoiding pregnancy or breastfeeding—to increasingly sophisticated pharmacologic regimens. A major milestone occurred in 1987 with the landmark “076 zidovudine” clinical trial, which showed a 67% reduction in transmission through the administration of zidovudine. Later, in the late 1990s and early 2000s, simplified regimens such as single-dose nevirapine expanded access to PMTCT in low-income and middle-income countries, although concerns regarding drug resistance soon emerged[2,3].

Over the past decade, a paradigm shift led by the World Health Organization (WHO) has taken place, moving from the so-called “option A” and “option B” strategies to “option B+.” First implemented in Malawi, option B+ recommends lifelong combination antiretroviral therapy (ART) for all pregnant and breastfeeding women living with HIV, regardless of CD4 count or clinical stage[3]. Today, a public health-oriented model predominates, aiming to maximize population-level impact by harmonizing adult and pediatric treatment guidelines[4].

Key components of standardized PMTCT protocols encompass several coordinated clinical strategies that operate across the prenatal, intrapartum, and postpartum continuum of care. Universal testing is implemented through an opt-out approach in which HIV screening is routinely performed unless the patient explicitly declines, ensuring early identification of maternal infection and timely entry into care. Once diagnosed, pregnant women initiate combination ART using 3-drug regimens, with tenofovir (TDF), lamivudine (3TC), and dolutegravir (DTG) currently preferred because of their high genetic barrier to resistance and rapid viral suppression. Intrapartum and postpartum management further strengthens prevention efforts: Women with a high or unknown viral load at delivery receive intravenous zidovudine, and all exposed infants receive risk-stratified neonatal prophylaxis, typically with nevirapine and/or zidovudine for a duration of 6 weeks to 12 weeks. Throughout pregnancy and breastfeeding, regular viral load monitoring is essential to detect treatment failure promptly and ensure sustained maternal viral suppression, which remains the most critical determinant of preventing vertical transmission[4-7].

The impact of PMTCT programs is unequivocal. Between 2003 and 2010, more than 100000 pediatric infections were averted, with cumulative estimates exceeding 600000 since 1995. Globally, new pediatric HIV infections declined from approximately 270000 in 2009 to 160000 in 2018. Countries such as Armenia, Belarus, Cuba, and Thailand have achieved WHO validation for the effective elimination of vertical transmission of both HIV and syphilis[1,2,8,9]. Moreover, ART coverage among pregnant women living with HIV has risen substantially, reaching 77% to 82% in the countries with the highest burden.

Despite substantial progress, several critical barriers continue to hinder the goal of eliminating vertical HIV transmission by 2030. Attrition along the PMTCT cascade remains a major challenge, particularly in regions such as sub-Saharan Africa, where nearly half of pregnant women living with HIV are lost between antenatal registration and delivery, and a similar proportion of infants fail to complete follow-up after initial testing[3]. Incident maternal infections also contribute significantly to ongoing transmission because seroconversion during pregnancy or breastfeeding often goes undetected when repeat testing is insufficient[7]. Concerns regarding HIV drug resistance further complicate prevention efforts; studies from Haiti and sub-Saharan Africa have documented high levels of resistance among newly diagnosed infants, especially to non-nucleoside reverse transcriptase inhibitors, prompting revisions to first-line pediatric regimens[5]. Structural barriers and stigma continue to undermine adherence; fear of discrimination and limited family support discourage many women from disclosing their HIV status or engaging consistently in care[8,9]. In addition, weak health systems—characterized by shortages of trained personnel, stockouts of medications and diagnostic supplies, and fragmentation between maternal-child health services and adult HIV programs—further compromise the effectiveness of PMTCT interventions[1].

Infants whose perinatal HIV infection likely occurred at the end of pregnancy, during delivery, or through breastfeeding tend to experience delayed disease progression, with an average survival of 6 years to 9 years, accounting for 80% of all cases of vertical transmission. However, the remaining 20% of children infected through early intrauterine transmission tend to have much more rapid disease progression in the absence of treatment, with mortality rates close to 80% within the first 3 years of life. Early diagnosis of infection is crucial to enable prompt initiation of ART, thereby preventing immune system deterioration and the development of severe early-onset pediatric acquired immunodeficiency syndrome[10].

Clinical trials such as the Children with HIV Early Antiretroviral Therapy (CHER) Trial, conducted in Africa from 2005 to 2011, have shown that very early initiation of ART in newborns and infants (within the first 3 months of life) reduces mortality and HIV progression compared with initiation at an older age[11]. Following publication of the first phase of this study in 2008, the WHO’s 2010 recommendations suggest earlier diagnostic testing for all perinatally exposed infants, enabling earlier initiation of ART and universally recommending ART for all children younger than 1 year of age[12].

In Ecuador, the implementation of a standardized PMTCT approach began in 2013 with publication of the “National Guideline for the Prevention and Control of Mother-to-Child Transmission of HIV and Congenital Syphilis”[13], which marked the first nationwide effort to unify clinical practices across Ministry of Health facilities. Over the following years, additional hospitals within the Integrated Public Health Network progressively adopted the protocol, expanding coverage and improving coordination between maternal and pediatric services. This process was further strengthened with the release of the updated 2019 “Clinical Practice Guideline for the Prevention, Diagnosis, and Treatment of HIV in Pregnant Women, Children, Adolescents, and Adults”[14], which aligned national recommendations with the WHO option B+ strategy and standardized the use of lifelong ART for all pregnant and breastfeeding women living with HIV. The period 2017-2023 therefore represents a consolidated phase of implementation, during which the national PMTCT strategy had already been adopted across most public healthcare institutions, allowing for a more accurate assessment of its effectiveness in routine clinical practice.

The Ecuadorian context presents unique challenges for PMTCT implementation. Geographic disparities limit access to timely prenatal care, particularly in rural areas; stigma and nondisclosure continue to affect adherence; and the coronavirus disease 2019 (COVID-19) pandemic disrupted follow-up, laboratory capacity, and continuity of care. Despite these barriers, national progress toward the global goal of eliminating vertical transmission by 2030 has been notable, with a reported transmission rate of 2.07% in 2022[14-16]. Facilitating factors include universal HIV screening during pregnancy, free access to ART, and the availability of neonatal prophylaxis. Persistent obstacles, however, include late maternal diagnosis, inconsistent follow-up, and health system fragmentation.

Ecuador’s standardized PMTCT protocol currently in use incorporates universal opt-out HIV testing, the use of TDF/3TC/DTG as the preferred maternal regimen, intrapartum zidovudine for women with a detectable or unknown viral load, and risk-stratified neonatal prophylaxis[14]. This approach has a differential impact on the various pathways of vertical transmission: It markedly reduces intrapartum and postpartum transmission, while early intrauterine transmission remains more likely in cases of late maternal diagnosis or suboptimal adherence.

Within this framework, the present study evaluated the effectiveness of the standardized PMTCT strategy implemented at a tertiary-level hospital in Guayaquil during the 2017-2023 period by analyzing maternal and neonatal outcomes and determining the incidence of vertical HIV transmission in a cohort of 320 HIV-exposed infants.

MATERIALS AND METHODS

Study design and setting

This was a retrospective observational study conducted at a tertiary-level referral center in Guayaquil, Ecuador. The study analyzed clinical records of HIV-exposed infants managed under the institutional PMTCT protocol between January 2017 and December 2023. All data were obtained from routine clinical documentation generated during maternal and neonatal care within the national PMTCT program.

Study population

The study population included all infants born to mothers living with HIV who received care at the hospital’s Maternal-Infant Unit and Neonatology Service during the study period. Maternal records were reviewed to determine HIV status, risk classification, ART regimen, and intrapartum management. Neonatal records were reviewed for prophylaxis, virologic testing, serologic follow-up, and final HIV status.

Inclusion and exclusion criteria

The inclusion criteria required that infants be born to mothers with confirmed HIV infection, be enrolled in the institutional PMTCT follow-up program between 2017 and 2023, and have at least 1 available virologic or serologic test result. Infants were excluded if their records were duplicated; if their clinical files lacked essential baseline information such as maternal HIV status, neonatal prophylaxis, or follow-up testing; or if they had been transferred to the institution after birth without accessible baseline data.

Maternal risk classification

Maternal risk for vertical transmission was categorized according to national guidelines. Women were considered low risk when they had an undetectable viral load (defined as fewer than 40 copies per milliliter at or near delivery), demonstrated consistent adherence to ART throughout pregnancy, and delivered by scheduled cesarean section or controlled vaginal delivery without complications. High-risk classification applied to mothers with a detectable or unknown viral load at delivery, poor adherence to or late initiation of ART, or obstetric complications such as unscheduled vaginal delivery or prolonged rupture of membranes exceeding 12 hours. Poor adherence was defined as documented interruptions of ART exceeding 2 weeks, missed pharmacy refills, or self-reported intake of less than 80% of prescribed doses.

Neonatal prophylaxis and feeding practices

Neonatal prophylaxis followed institutional and national protocols. Infants classified as low risk received oral zidovudine for 4 weeks, whereas those considered high risk received triple prophylaxis consisting of zidovudine, 3TC, and nevirapine for 6 weeks. All infants were exclusively formula-fed because breastfeeding is not permitted under the national PMTCT strategy.

Virologic and serologic follow-up

Virologic follow-up was conducted at 3 standardized time points: At birth, 2 weeks after completing prophylaxis, and after 4 months of age. Based on these results, infants were categorized as under evaluation when virologic testing remained incomplete, HIV-negative when all viral loads were undetectable, or HIV-positive when a detectable viral load was confirmed by repeat testing. Serologic testing using an enzyme-linked immunosorbent assay was performed at birth, when all infants tested reactive due to the presence of maternal antibodies, and again at 18 months to document seroreversion. Infants who demonstrated loss of maternal antibodies at this stage were classified as HIV-exposed seroreverters.

Management of loss to follow-up

Infants who discontinued scheduled follow-up and whose caregivers could not be contacted were classified as lost to follow-up. Their available clinical information was retained for descriptive analyses, but they were excluded from the denominator used to calculate the final vertical transmission incidence. Whenever possible, cross-institutional verification was attempted, particularly during the COVID-19 pandemic, when service disruptions and transfers between facilities were more frequent.

Ethical considerations

This retrospective study was approved by the Ethics Committee of the hospital, which authorized the use of anonymized clinical data for research purposes. All data were fully anonymized in accordance with institutional regulations, national confidentiality standards, and the principles of the Declaration of Helsinki.

The study used anonymized retrospective clinical records generated during routine care within the national prevention of mother-to-child transmission program. According to institutional policy and the Ethics Committee’s determination, the requirement for individual informed consent was waived because the research involved no direct patient contact, no additional procedures, and no identifiable information.

Statistical analysis

Data were entered and analyzed using Microsoft Excel. Descriptive statistics were used to summarize maternal characteristics, neonatal outcomes, and follow-up results. Categorical variables were expressed as n (%). The incidence of vertical HIV transmission was calculated as the proportion of confirmed HIV-positive infants among all exposed infants with complete diagnostic evaluation. A 95% confidence interval was computed for the transmission rate. Infants lost to follow-up were excluded from the denominator for incidence calculations but were described separately. No comparative statistical tests were performed between low-risk and high-risk maternal groups because the study was not designed to evaluate differences between these categories.

RESULTS

In total, 320 HIV-exposed infants were enrolled in the institutional PMTCT program between 2017 and 2023. The sex distribution was balanced, with 158 male (49.4%) and 162 female (50.6%) infants. Other baseline characteristics are summarized in Table 1. Maternal characteristics showed a wide age distribution ranging from 14 years to 40 years, with most mothers (77.8%) between 20 years and 30 years of age. Regarding the timing of HIV diagnosis, 61.6% were diagnosed before pregnancy, 30.6% were diagnosed during the first trimester, and 7.8% received a late diagnosis in the third trimester or intrapartum. Cesarean section was the predominant mode of delivery (97.2%), while only 0.9% had controlled vaginal delivery and 1.9% had expulsive or urgent vaginal birth. ART regimens reflected national transitions: 47.5% received raltegravir + TDF + emtricitabine before 2022, 32.8% received TDF + 3TC + DTG after its adoption as the preferred regimen, and 19.7% received alternative regimens. At delivery, 88.1% of mothers had an undetectable viral load (< 40 copies/mL), 9.7% had transient elevations (“blip” viral load), and 2.2% had viral loads above 1000 copies/mL. In accordance with the PMTCT strategy protocol, any detectable viral load level (> 40 copies/mL) is considered high risk.

Table 1 Baseline maternal and neonatal characteristics (2017-2023).

Variable	n (%)	Additional details
Maternal age (range: 14-40 years)
Between 20-30 years	249 (77.8)
Other age groups	71 (22.2)	1 teenage pregnancy (14 years)
Timing of HIV diagnosis
Before pregnancy	197 (61.6)	Diagnosis prior to conception
First trimester	98 (30.6)	Early prenatal diagnosis
Late diagnosis (third trimester or intrapartum)	25 (7.8)	Diagnosis during late pregnancy or at delivery
Mode of delivery
Cesarean section	311 (97.2)	Elective or indicated cesarean
Controlled vaginal delivery	3 (0.9)	Optimal maternal conditions
Expulsive/urgent vaginal delivery	6 (1.9)	Late diagnosis or emergent presentation
Maternal ART regimen during pregnancy
RAL + TDF + FTC	152 (47.5)	Predominant regimen before 2022
TDF + 3TC + DTG	105 (32.8)	Standardized regimen since 2022
Other regimens	63 (19.7)	Alternative ART combinations
Maternal viral load at delivery
Undetectable (< 40 copies/mL)	282 (88.1)	According to institutional laboratory thresholds
Blip viral load (41-1000 copies/mL)	31 (9.7)	Transient elevation
> 1000 copies/mL	7 (2.2)	High-risk viral load
Sex of the newborn
Male	158 (49.4)
Female	162 (50.6)

3TC: Lamivudine; ART: Antiretroviral therapy; DTG: Dolutegravir; FTC: Emtricitabine; HIV: Human immunodeficiency virus; RAL: Raltegravir; TDF: Tenofovir.

Regarding maternal ART, treatment patterns reflected the national transition in recommended regimens over the study period. Prior to 2020, most pregnant women received a combination of raltegravir, TDF, and emtricitabine, in accordance with earlier national guidelines. Beginning in 2020, DTG was introduced as part of first-line therapy; however, some clinicians adopted it cautiously because of initial concerns about potential neural tube defects reported in early observational studies. By 2022, following updated national recommendations and accumulating global evidence supporting its safety and superior efficacy, DTG combined with TDF and 3TC became the standardized and widely implemented regimen across the institution.

As shown in Figure 1, most infants had completed the diagnostic process by the end of the study period, with 265 children (82.8%) achieving seroreversion at 18 months. An additional 34 infants (10.6%) remained under evaluation because they had not yet reached the age required for final serologic testing, although the majority had already been classified as HIV-negative based on virologic results obtained earlier in follow-up. Ten infants (3.1%) were transferred to other hospitals; 8 continued their PMTCT follow-up at the receiving institutions, while 2 were referred for specialized care after confirmation of HIV infection. Eleven infants (3.4%) were classified as lost to follow-up. All had previously tested HIV-negative but did not complete the final enzyme-linked immunosorbent assay required to document seroreversion.

Figure 1  Distribution of perinatally exposed infants according to their status at the end of the 6-year study period.

Throughout the study period, a significant majority of the patients (91.25%) were classified as HIV-negative. This group included both children identified as seroreverters at 18 months and those who were perinatally exposed but ultimately determined to be HIV-negative at 4 months. Meanwhile, 2.19% of the patients remained under evaluation because their final status had not been established by the end of the study period (Figure 2).

Figure 2 Distribution of perinatally exposed infants according to their final human immunodeficiency virus status at the end of the study period. HIV: Human immunodeficiency virus.

Only 2 infants (0.65%) were diagnosed with HIV infection during the study period. Infants lost to follow-up were excluded from the denominator for incidence calculations. The resulting vertical transmission rate was 0.65% (2/309). The 95% confidence interval for this rate was 0.18% to 2.35%. If all 11 infants lost to follow-up were assumed to be HIV-positive, the transmission rate would increase to 4.1% (13/320). Although unlikely given their previously negative virologic test results, this scenario underscores the importance of strengthening follow-up systems. The findings are illustrated in Figure 3, which depicts the vertical transmission rate observed throughout the 2017-2023 study period.

Figure 3 Vertical human immunodeficiency virus transmission rate during the 2017-2023 study period. HIV: Human immunodeficiency virus.

Risk factors in the 2 HIV-positive cases

Both HIV-positive infants were born to mothers residing in remote rural areas with limited access to prenatal care, and several converging risk factors contributed to their infection. In both cases, the mothers received a late HIV diagnosis, either in the third trimester or intrapartum, which resulted in minimal exposure to ART before delivery. Obstetric complications, including preterm premature rupture of membranes, further increased the likelihood of transmission. Additionally, significant geographic and socioeconomic barriers hindered the mothers’ ability to attend scheduled follow-up visits, limiting opportunities for timely monitoring and intervention.

Despite strict adherence to neonatal triple prophylaxis, both infants tested positive—1 at birth (very early diagnosis) and the other at 3 months (early diagnosis). Both were promptly transferred to the national pediatric referral center and initiated on ART.

Overall adherence to the institutional PMTCT protocol was high. More than 90% of mothers attended scheduled follow-up visits, completed ART regimens, and complied with neonatal prophylaxis recommendations. Deviations from the protocol were primarily associated with late presentation to care or external factors such as geographic isolation.

Impact of the COVID-19 pandemic

The COVID-19 pandemic (2020-2021) had a measurable impact on program continuity, leading to temporary reductions in follow-up attendance, delays in obtaining viral load testing, and an increase in transfers between institutions as families sought care in locations with fewer service disruptions. These operational challenges also contributed to a higher likelihood of loss to follow-up, particularly among families facing mobility restrictions or socioeconomic hardship.

Follow-up attendance decreased by approximately 20% during the COVID-19 period compared with pre-pandemic years and returned to near-baseline levels by 2022. Most of the 11 infants ultimately classified as lost to follow-up belonged to this period, reflecting the broader national disruptions in healthcare access that affected routine maternal and child health services across the country.

DISCUSSION

The findings of this study demonstrate that the standardized PMTCT strategy implemented at a tertiary-level hospital in Guayaquil achieved a remarkably low vertical HIV transmission rate of 0.65%, well below the national estimate of 2.07% and within the threshold established by the WHO for the elimination of mother-to-child transmission. The near-universal uptake of maternal ART, high adherence to neonatal prophylaxis, and consistent follow-up contributed substantially to these outcomes[17-20].

The equal distribution of HIV-exposed infants by sex aligns with global evidence indicating no biological predisposition to vertical transmission[21,22]. Program adherence was generally high, with more than 90% of mothers completing scheduled visits and neonatal prophylaxis. This level of engagement reflects the effectiveness of the institutional PMTCT model, which integrates maternal and pediatric services and ensures continuity of care.

Several factors likely explain why this hospital outperformed national averages. First, the institution benefits from a specialized multidisciplinary team with extensive experience in managing HIV during pregnancy and infancy. Second, the availability of antiretroviral drugs facilitated rapid viral suppression among pregnant women. Although raltegravir-based therapy was used earlier in the study period, the adoption of DTG/TDF/3TC from 2022 onward strengthened maternal viral load control, consistent with global evidence supporting DTG’s superior efficacy and tolerability. Third, the hospital maintained reliable access to laboratory testing, including viral load monitoring, which is essential for identifying high-risk pregnancies and adjusting management accordingly. Fourth, the sociodemographic profile of the mothers receiving care at this institution may have also contributed to the high adherence observed in this cohort. Most were employed women with medium to higher educational levels, which have been associated with better understanding of treatment recommendations, greater health-seeking behavior, and improved adherence to scheduled follow-up visits. This profile may have facilitated consistent ART adherence during pregnancy and reliable attendance at neonatal follow-up appointments, thereby strengthening the overall effectiveness of the PMTCT strategy.

The 2 cases of vertical transmission highlight persistent challenges in Ecuador’s broader health system. Both infants were born to mothers residing in remote rural areas with limited access to prenatal care, who received a late HIV diagnosis and had minimal exposure to ART before delivery. These findings mirror reports from other countries in the region, where geographic and socioeconomic barriers remain major determinants of vertical transmission[23-26]. Despite strict adherence to neonatal triple prophylaxis, the infants’ risk was already elevated because of delayed maternal diagsnosis, underscoring the importance of early testing and universal prenatal screening.

The COVID-19 pandemic had a measurable impact on program performance. Reduced mobility, temporary service disruptions, and delays in laboratory testing contributed to an increase in missed appointments and transfers between institutions. Most infants lost to follow-up were from this period, reflecting national and global trends showing that the pandemic disproportionately affected maternal-child HIV services[18]. Nevertheless, the hospital maintained a high level of program continuity, which likely prevented additional cases of vertical transmission.

Compared with other centers in Ecuador and the wider Latin American region, the results of this study are consistent with reports showing that rigorous implementation of option B+ protocols can reduce transmission to less than 1%. Countries that have achieved elimination, such as Cuba and Thailand, share similar characteristics: Strong integration of maternal and pediatric services, universal screening, and uninterrupted ART supply. Reports from other tertiary centers in the Andean subregion show similar outcomes when option B+ protocols are rigorously applied, with transmission rates consistently below 1%[1,2,8,9].

The standardized PMTCT strategy is currently implemented across most public healthcare institutions in Ecuador, although coverage and adherence vary by region. The present findings suggest that these components are equally effective in the Ecuadorian context when consistently applied.

This study has several limitations. Its retrospective design relies on the accuracy and completeness of clinical records, which may introduce information bias. The analysis was conducted at a single tertiary-level hospital, which may limit the generalizability of the findings to other regions of Ecuador with different resource levels or patient populations. Additionally, 11 infants (3.4%) were lost to follow-up, most during the COVID-19 pandemic, which may have influenced the final transmission estimate. Although these infants had previously tested HIV-negative, their absence introduces uncertainty. Maternal variables such as socioeconomic status, timing of ART initiation, and adherence measures were not consistently available, limiting the ability to perform more detailed analyses. Despite these limitations, the study provides valuable real-world evidence on the effectiveness of standardized PMTCT implementation in Ecuador.

CONCLUSION

This 6-year retrospective analysis demonstrates that the standardized PMTCT strategy implemented at a tertiary-level hospital in Guayaquil achieved a vertical HIV transmission rate of 0.65%, well below national estimates and within the threshold for elimination. High maternal adherence to ART, consistent neonatal prophylaxis, and strong integration between maternal and pediatric services were central to this success. The sociodemographic profile of the mothers—most of whom were employed and had medium to higher educational levels—likely contributed to improved treatment adherence and follow-up.

The 2 cases of vertical transmission underscore persistent challenges in rural and underserved areas, where late maternal diagnosis and limited access to prenatal care remain critical barriers. Strengthening early testing, expanding access to ART, and improving continuity of care in remote regions are essential to further reducing transmission.

Despite limitations inherent to its retrospective, single-center design, this study provides valuable real-world evidence supporting the effectiveness of Ecuador’s standardized PMTCT protocol. Continued efforts to enhance service integration, ensure uninterrupted ART supply, and address structural barriers will be key to sustaining progress toward the national goal of eliminating mother-to-child HIV transmission.