Mother-to-child transmission of HIV and its predictors among HIV-exposed infants at a PMTCT clinic in northwest Ethiopia

  • Digsu Negese Koye1Email author and

    Affiliated with

    • Berihun Megabiaw Zeleke1

      Affiliated with

      BMC Public Health201313:398

      DOI: 10.1186/1471-2458-13-398

      Received: 10 July 2012

      Accepted: 22 April 2013

      Published: 27 April 2013

      Abstract

      Background

      Mother-to-child transmission of HIV (MTCT) accounts for more than 90% of pediatric Acquired Immunodeficiency Syndrome (AIDS) cases. Prevention of mother to child transmission (PMTCT) programs are provided for dual benefits i.e. prevention of HIV transmission from mother to child and enrolment of infected pregnant women and their families into antiretroviral treatment (ART). This study assessed risk and predictors of HIV transmission among HIV-exposed infants on follow up at a PMTCT clinic in a referral hospital.

      Methods

      Institution based retrospective follow up study was carried at Gondar University referral hospital PMTCT clinic. All eligible records of HIV-exposed infants enrolled between September 2005 and July 2011 were included. A midwife nurse collected data using a structured data extraction format. Data were then entered in to EPI INFO Version 3.5.1 statistical software and analyzed by SPSS version 20.0. Both bivariate and multivariate analyses were carried out to identify associations.

      Results

      A total of 509 infant records were included in the analysis. The median age of infants at enrolment to follow up was 6 weeks (inter quartile range [IQR] = 2 weeks). A total of 51(10%, 95% CI: 7.8% - 13%) infants were infected with HIV. Late enrolment to the exposed infant follow up clinic (Adjusted Odds Ratio [AOR] = 2.89, 95% CI: 1.35, 6.21), rural residence (AOR = 5.05, 95% CI: 2.34, 10.9), home delivery (AOR = 2.82, 95% CI: 1.2, 6.64), absence of maternal PMTCT interventions (AOR = 5.02, 95% CI: 2.43, 10.4) and mixed infant feeding practices (AOR = 4.18, 95% CI: 1.59, 10.99) were significantly and independently associated with maternal to child transmission of HIV in this study.

      Conclusions

      There is a high risk of MTCT of HIV among exposed infants on follow up at the PMTCT clinic of the University of Gondar referral hospital. The findings of this study will provide valuable information for policy makers to enhance commitment and support for rural settings in the PMTCT scaling-up program.

      Keywords

      HIV-exposed infants HIV transmission Predictors Ethiopia

      Background

      The HIV pandemic created an enormous challenge to the survival of humankind worldwide. At the end of 2011, an estimated 34 million people were living with HIV globally. There was 2.5 million new HIV infections, including 330, 000 among children less than 15 years. The annual number of people dying from AIDS-related causes worldwide is steadily decreasing. In 2011, 1.7 million people worldwide died from AIDS related causes, down 24% from the peak in 2005 [1].

      Besides the dominant heterosexual transmission, vertical HIV transmission from mother to child accounts for more than 90% of paediatric AIDS. PMTCT programs provide for both prevention of HIV transmission from mother to child and enrolment of infected pregnant women and their families into antiretroviral treatment (ART). It is undertaken by the government of Ethiopia in an effort to mitigate the impacts of the epidemic in the general population and amongst children in particular. The availability and use of short-course antiretroviral (ARV) prophylaxis-a safe and well-tolerated regimen-can contribute significantly to PMTCT during childbirth [2].

      Ethiopia is one of the countries most severely hit by the epidemic. According to Ethiopian demographic and health survey 2011, the national adult HIV prevalence is reported to be 1.5% (4.2% in urban and 0.6% in rural areas) [3]. Highest prevalence occurs in the 15–24 age groups and prevalence is higher among females than males in both urban and rural areas. Prevalence appears to have levelled off in urban areas but continues to rise in rural areas, where 85% of the population lives [2].

      Ethiopia has adopted the World Health Organization (WHO) four pronged PMTCT strategy as a key entry point to HIV care for women, men and families. These are: primary prevention of HIV infection, prevention of unintended pregnancies among HIV-infected women, prevention of HIV transmission from HIV-infected women to their offspring, provision of care and support to women infected with HIV, their infants and families [4].

      Although there are reports on the effectiveness and outcomes of PMTCT from many countries, there are limited studies conducted in Ethiopia to assess the risk of HIV transmission and its predictors among exposed infants. One retrospective study conducted in Addis Ababa, Ethiopia, showed 11.8% HIV prevalence among exposed infants [5]. Provision of baseline information about the risk and predictors of HIV transmission among HIV exposed infants is of immense importance. This study thus aimed to assess the risk of HIV transmission and its predictors among HIV exposed infants who had follow up at PMTCT clinic of Gondar University Hospital.

      Methods

      Institution based retrospective follow up study was carried out among infants and mothers who were on follow up at the PMTCT clinic.

      Study area and setting

      The study was conducted at Gondar University referral hospital PMTCT clinic from March to April 2012. Gondar, situated at 748 km from Addis Ababa, (the Ethiopian capital) has about a total population of 207, 044 (in 2007). The hospital is located in Gondar city, Amhara National Regional State, northwest Ethiopia. It is one of oldest health institutions in northwest Ethiopia, which is the referral centre for four district hospitals in the area providing service for over 5 million people in the catchment area. Apart from other services, the hospital is providing HIV chronic care including PMTCT services for clients since 2005 as one component of comprehensive HIV/AIDS care and support program.

      Study population

      All records of HIV-exposed infants enrolled between September 2005 and July 2011 at the PMTCT clinic of Gondar University referral hospital were included in this study. The records of infants transferred in from other sites were excluded.

      Follow up of HIV-positive mothers and their infants in northwest Ethiopia

      PMTCT protocols were based on WHO guidelines evolved over the duration of the study period in response to changing international guidelines and newly available information. Throughout the course of the program, women who were eligible for HIV treatment based on their own clinical and immunologic status received combination ART.

      According to the guidelines, follow up schedule of infants born to HIV-positive mothers is: at 6 hours after birth, 6th day and then at the 6th, 10th and 14th week of life. Thereafter, it is on monthly basis until 6th month of age and every 3 months until age of 18 months for asymptomatic infants. However, children were followed for variable periods of time as their HIV infection status may be declared at different times. Cotrimoxazole prophylaxis is usually started when the infant is aged 4–6 weeks. HIV testing of infants born to HIV-positive mothers was according to the guidelines for PMTCT of HIV in Ethiopia [2]. Deoxyribonucleic acid (DNA) Polymerase Chain Reaction (PCR) testing is done at 6 weeks or as early as possible thereafter. The child will be referred for HIV/ART care clinic if child has a positive virological test or suspected of having symptomatic HIV or displays any severe classifications possibly due to HIV or has positive antibody test under 18 months and 2 or more of the following: oral thrush, severe pneumonia or severe sepsis.

      Operational definitions

      ARV prophylaxis

      Short term use of ARV drugs in the mother and/or infant to reduce MTCT [2].

      Data collection and management

      Data on socio-demographic information, birth weight of the infant, infant prophylaxis, maternal PMTCT interventions, HIV test result and related interventions were collected using a structured data collection format. The format was pretested at Gondar health center on twenty records and improved accordingly. Data were collected by a midwife nurse who works at the PMTCT clinic of the hospital. Data were then checked, coded and entered in to EPI info version 3.5.1 version and analyzed by SPSS version 20.0. Most of the variables were fitted to the bivariate logistic regression. Then all variables having p value ≤ 0.2 in the bivariate analysis were further entered into multivariate logistic regression model. Backward Logistic Regression (LR) method was employed and variables having p value < 0.05 were taken as significant predictors. Crude and adjusted odds ratios with their 95% confidence intervals were calculated.

      Ethical considerations

      Ethical clearance was obtained from Institutional Review Board of the University of Gondar. Permission letter was obtained from the hospital administration. As this was a retrospective study using secondary data, informed consent from individual patients was not possible. Names and medical registration numbers of patients were not included in the study.

      Results

      A total of 521 mother-infant pairs were enrolled in to the PMTCT clinic during the study period. Among these, 509 records were included in the final analysis. Twelve records were incomplete and excluded. The median age at enrolment to HIV-exposed infant follow up clinic was 6 weeks (IQR = 2 weeks). Nearly half (51.7%) of them were males and majority (83.3%) were from urban areas. Three hundred sixty eight (81.2%) of the mothers were enrolled to ART clinic. However, 92(18.1%) mothers did not receive any PMTCT interventions during pregnancy and child birth. Majority (90.4%) of the exposed infants were born at a health institution. Almost all (97.8%) mothers were alive when infants started follow up and majority (85.1%) of the infants took ARV prophylaxis at birth (Table 1).
      Table 1

      Socio-demographic and clinical characteristics of HIV exposed infants and their mothers who had a follow up at Gondar University Referral Hospital

      Variables

      Frequency

      Percent

      Age at enrolment

        

        ≤ 6 weeks

      353

      69.4

        > 6 weeks

      156

      30.6

      Sex

        

        Male

      263

      51.7

        Female

      246

      48.3

      Residence

        

        Urban

      424

      83.3

        Rural

      85

      16.7

      Place of Birth

        

        Hospital

      403

      79.2

        Health center

      57

      11.2

        Home

      49

      9.6

      Maternal status

        

        Alive

      498

      97.8

        Dead

      11

      2.2

      Maternal enrolment to ART care (n = 453)

        

        Enrolled

      368

      81.2

        Not enrolled

      85

      18.8

      Maternal PMTCT intervention*

        

        None

      92

      18.1

        sdNVP

      85

      16.7

        sdNVP + AZT for 7 days

      10

      2.0

        sdNVP + AZT for 4 weeks

      3

      .6

        Already on ART

      189

      37.1

        sdNVP + AZT for 7 days + 3TC

      130

      25.5

      Infant ARV prophylaxis at birth (n = 495)

        

        Received

      421

      85.1

        Not Received

      72

      14.5

        Not known

      2

      0.4

      Infant ARV prophylaxis during follow up (n = 491)*

        

        None

      75

      15.3

        sdNVP

      99

      20.2

        sdNVP + AZT for 7 days

      277

      56.4

        sdNVP + AZT for 4 weeks

      40

      8.1

      *AZT, Zidovidine; sdNVP, Single dose Neverapine; 3TC, Lamuvidine.

      At enrollment, most (78.8%) infants were on exclusive breast feeding, 67(13.3%) on exclusive replacement feeding, while the rest 40(7.9%) were on mixed feeding. Forty three (8.4%) infants had diagnosis suggestive of HIV infection. The most common diagnosis was Pneumonia/Lower respiratory tract infections, followed by persistent diarrhea and hepato-spleenomegaly. More than three quarters (80.5%) of the infants started cotrimoxazole prophylaxis at enrolment.

      Risk of maternal to child HIV transmission

      Of all 509 infants, 51(10%, 95% CI: 7.8% - 13%) were HIV-infected. Most were diagnosed by both DNA/PCR at their six week of age and rapid antibody test at a later age. Among those HIV positive after PMTCT follow up, most were from rural than urban (28.2% Vs 6.4%) residence.

      Predictors of maternal to child HIV transmission

      As clearly depicted on the multivariate logistic regression, late enrolment to the exposed infant follow up clinic, rural residence, delivery at home, absence of maternal PMTCT intervention and mixed infant feeding practices were significantly and independently associated with maternal to child HIV transmission. However, sex, maternal status (living or dead) and infant baseline cotrimoxazole prophylaxis were not significantly associated with MTCT.

      Accordingly, infants who started follow up after six weeks of age were at a 2.89 (AOR = 2.89, 95% CI: 1.35, 6.21) times higher risk of MTCT as compared to their counterparts. Infants of rural dwelling mothers were at a 5.05 (AOR = 5.05, 95% CI: 2.34, 10.9) times higher risk of vertical HIV transmission as compared to urban dwelling mothers. Infants delivered at home had 2.82 (AOR = 2.82, 95% CI: 1.2, 6.64) times higher risk of MTCT compared to those delivered at health institution. If the mother did not receive any form of PMTCT intervention during pregnancy or child birth there is a fivefold (AOR = 5.02, 95% CI: 2.43, 10.4) risk of MTCT as compared to at least one form of PMTCT intervention. Mixed feeding was also another important predictor in which the risk of MTCT was about four (AOR = 4.18, 95% CI: 1.59, 10.99) times higher as compared to exclusive breastfed (Table 2).
      Table 2

      Multivariate logistic regression analysis of predictors of vertical transmission at Gondar University Referral Hospital, Northwest Ethiopia

      Variables

      HIV status

      Crude OR (95% CI)

      Adjusted OR (95% CI)

       

      Positive

      Negative

        

      Age at enrolment

          

        ≤ 6 weeks

      15

      338

      1.0

      1.0

        > 6 weeks

      36

      120

      6.76 (3.57, 12.79)*

      2.89 (1.35, 6.21)*

      Sex

          

        Male

      26

      237

      0.97 (0.54, 1.73)

      **

        Female

      25

      221

      1.0

       

      Residence

          

        Urban

      27

      397

      1.0

      1.0

        Rural

      24

      61

      5.79 (3.14, 10.67)*

      5.05 (2.34, 10.9)*

      Place of Birth

          

        Health institution

      33

      427

      1.0

      1.0

        Home

      18

      31

      7.5 (3.81, 14.83)

      2.82 (1.2, 6.64)

      Maternal status

          

        Alive

      47

      451

      1.0

      **

        Dead

      4

      7

      5.48 (1.55, 19.42)*

       

      Maternal PMTCT intervention

          

        Yes

      20

      397

      1.0

      1.0

        No

      31

      61

      10.09 (5.41, 18.82)*

      5.02 (2.43, 10.4)*

      Infant feeding practice

          

        Exclusive breast feeding

      26

      371

      1.0

      1.0

        Exclusive replacement feeding

      8

      59

      1.94 (0.84,4.48)

      1.72 (0.65, 4.53)

        Mixed feeding

      16

      24

      9.51 (4.51,20.08)*

      4.18 (1.59, 10.99)*

      History of infant ARV prophylaxis at birth

          

        Received

      21

      400

      1.0

       

        Not Received

      30

      44

      12.99 (6.86, 24.6)*

      **

      Infant ARV prophylaxis during follow up

          

        None

      30

      45

      8.22 (2.32, 29.10)*

      **

        sdNVP

      5

      94

      0.66 (0.15, 2.89)

       

        sdNVP + AZT 7 days

      12

      265

      0.56 (0.15, 2.07)

       

        sdNVP + AZT 4 weeks

      3

      37

      1.0

       

      Baseline Cotrimoxazole

         

      **

        Yes

      44

      364

      1.0

       

        No

      7

      92

      0.63 (0.28, 1.44)

       

      *Significant at P-Value <0.05.

      * *non significant from the multivariate logistic regression (Backward LR method).

      Discussion

      Prevention of mother-to-child transmission of HIV-1 is a major public health challenge in many resource-poor countries including Ethiopia. This study was based on a retrospective analysis of data from a routine PMTCT program in a referral hospital. According to this study, among HIV-exposed infants on follow up at the PMTCT clinic of Gondar University referral hospital, one-tenth of HIV-exposed infants got HIV-infected. We included only those infants whose mothers were tested HIV-positive and followed up until the infant’s HIV status was confirmed.

      Compared to high income countries (<2%) [6, 7], and reports from India (6.5%) and South Africa (5.9%) [8, 9], in our study risk of MTCT was very high. This may be due to the universal use of highly active antiretroviral therapy for pregnant women, elective caesarean sections and avoidance of breastfeeding in developed countries [10]. However, such preventive approaches are limited in poor countries due to poor funding, social and cultural norms [11].

      Factor that put an infant to a higher risk of HIV transmission were; late enrolment to the follow up clinic, rural residence, home delivery, absence of maternal PMTCT interventions and mixed infant feeding practices. The reasons for the high relevance of these factors could be overlapping to one another. Firstly, infants born from rural mothers are prone for mixed feeding. Secondly, rural mothers are less likely to screen and enroll themselves to antenatal care or health institution delivery and thereby less likely to benefit from PMTCT interventions. As a result many women in resource-poor countries do not have access to prenatal care and often present with infection lately [12]. All these health care disadvantages in the rural settings compared to the urban areas would put infants of rural mothers at a higher risk of MTCT of HIV and thereby mortality [10].

      Similar to studies done so far in different corners of the world [9, 13, 14], if the mother received PMTCT interventions during pregnancy, the risk of MTCT of HIV was only 4.8%. The result of this study is in line with the widely accepted fact that providing ARVs to both the mother and the newborn prevents MTCT of HIV [15]. In this study, the risk of MTCT was 40.5% among infants with no prophylaxis, 5.1% for infants who received sdNVP prophylaxis and 4.9% for infants who took combined (sdNVP + AZT) prophylaxis. The difference was significant between no prohylaxis and sdNVP groups. However, there was no statistical difference between sdNVP and combined (sdNVP + AZT) prophylaxis regimens. This is similar to previous studies reporting a higher benefit of ARV prophylaxis to exposed infants [5, 9, 13] especially with combined regimens. A cohort study in Abidjan, Côte d’Ivoire, reported a 72% reduction of MTCT [16] with ZDV + sdNVP compared to ZDV alone while another study reported an increasing drug number and duration would significantly decrease the risk of MTCT [9]. However, this difference was not observed in the current study partly due to the lower sample size.

      Limitations

      As we used secondary data from a PMTCT clinic, it was difficult to control for inconsistencies and missing values. Maternal HIV-1 viral load and duration of disease and child’s vaccine status were not systematically recorded and could not be taken into account. This study did not aim to differentiate when MTCT occurred i.e. pre-partum, intra-partum or post partum period. The fact that all potential factors were not included and assessed may affect generalization of predictors in this study. Despite these limitations, to the best of our knowledge, this study presented primary results of the effectiveness of routine PMTCT interventions in Gondar University referral hospital.

      Conclusion

      There is a high risk of MTCT of HIV among exposed infants on follow up at the PMTCT clinic of the University of Gondar referral hospital. The risk of MTCT of HIV was higher among those from rural areas, enrolled after six weeks of age, had no maternal PMTCT intervention, delivered at home and mixed fed infants. The findings of this study will provide valuable information for policy makers in the PMTCT scaling-up program to focus on rural settings.

      Declarations

      Acknowledgements

      We are very grateful to the University of Gondar, Research and Publications Office for technical and financial support of this study.

      Authors’ Affiliations

      (1)
      Department of Epidemiology and Biostatistics, College of Medicine and Health Sciences, University of Gondar

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      17. Pre-publication history

        1. The pre-publication history for this paper can be accessed here:http://​www.​biomedcentral.​com/​1471-2458/​13/​398/​prepub

      Copyright

      © Koye and Zeleke; licensee BioMed Central Ltd. 2013

      This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://​creativecommons.​org/​licenses/​by/​2.​0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.