Background
HIV infected infants are at increased risk of life-threatening infections such as pneumonia due to
Pneumocystis carinii,
Mycobacterium tuberculosis, and nutritional deficiencies and other infections, such as malaria and diarrhea, which are often complicated to treat and are the leading cause of infant mortality in HIV-infected newborns and infants [
6].
Following the WHO recommendations, in Ethiopia, the rapid scale-up of ART provides access for pregnant women living with HIV and has averted more than 900,000 new HIV infections among children since 2009 [
5]. A recent report from Tigray Regional Health Bureau showed that the prevalence of HIV in exposed infants has declined consistently from a peak of 9% in 2010/11 to 3.1% in 2014/15 [
7]. HIV transmission rate from mother to child at 6 weeks decreased from 19% in 2009 to 10% in 2013 with the final HIV transmission rate from mother to child, including during breastfeeding decreasing from 39 to 25% during the same year period. On the contrary, the number of women (15–49 years old) acquiring HIV increased by 74% since 2009 which increased from 4500 in 2009 to 7800 in 2013 (
http://www.unaids.org/sites/default/files/media/documents/UNAIDS_GlobalplanCountryfactsheet_ethiopia_en.pdf). Since 2001, due to the launch of a national program for PMTCT of HIV infection by the Ethiopian Ministry of Health, the number of facilities with PMTCT service has reached 1,445 providing ARV prophylaxis for 10,302 HIV positive pregnant women and 4,945 exposed infants in 2011 [
8]. The prophylactic medication coverage during pregnancy has improved significantly in east and southern Africa but it is still lower than the 80% target because of limited healthcare provision during childbirth [
8].
National guidelines in Ethiopia recommends that infants exposed to HIV should be tested by polymerase chain reaction (PCR) for the detection of viral nucleic acid at 6 weeks of age using dried blood spot samples wherever the facilities and resources for these assays are available (
http://www.ilo.org/wcmsp5/groups/public/%2D%2D-ed_protect/%2D%2D-protrav/%2D%2D-ilo_aids/documents/legaldocument/wcms_125389.pdf). Almost all regional states in Ethiopia are currently implementing this programme. However, a scientific study that can clearly show the prevalence and associated risk factors for exposed infants in Tigray region has not been previously performed. Hence, the aim of this study was to assess the prevalence and associated risk factors of HIV among exposed infants in Tigray, Northern Ethiopia.
Methods
Study area and sample size determination
The study was conducted in 83 public ART site health facilities in Tigray Regional State, Northern Ethiopia spread across 54,572.6 sq. km. As projected from the 2007 census, the region has an estimated total population of 5,151,998 [
10]. The region has 240 public health facilities serving the population of Tigray and neighboring areas of other regions. The region has one specialized hospital, 15 general hospitals and 224 health centers; of these 117 are governmental ART site health institutions. The sample size (
n = 350) was determined using a single population proportion formula. A non-probability convenient consecutive sampling technique was employed to enroll the study participants. The number of study participants in each zone were allocated proportionally to its size using the proportional allocation formula.
Study participants and study variables
A cross-sectional study was employed among all HIV exposed infants from the age of 6 weeks and less than 18 months, attending PMTCT clinic in the governmental ART site health facilities from September 01 to December 30, 2016. Exposed infants who were critically ill and infants whose parents were unwilling to give their consent were excluded from the study.
Data collection
Clinical data such as CD4 count of the mother during delivery, infant birth weight and treatment history (eg: infant ARV prophylaxis at birth, maternal PMTCT intervention) was collected from infant medical record and mother’s history recording charts using a checklist. Socio-demographic data such as age, sex, residence, occupation and other risk factors of the study participants were collected for each study participants from mothers using a structured questionnaire by trained personnel.
Quality assurance
Questionnaire was first prepared in English and translated into Tigrigna (local language). Training was provided to data collectors on sample collection before prior to data collection. The collected data were reviewed for completeness, accuracy, clarity, and consistency by data collectors and the principal investigator. A questionnaire was checked and manually updated if there were incomplete or unrecorded values, and unlikely responses and laboratory results were recorded in the laboratory data result in formats coded for each participant.
Abbott real-time HIV-1 qualitative controls (high positive and negative) were used to establish run validity of the Abbott real-time HIV-1 qualitative assay when used for the qualitative detection of HIV-1 nucleic acid from human dried blood spots (DBS) in each batch.
Data analysis and interpretation
Each collected data was labeled using specific patient codes. The data were entered into Epi Info version 7. Data was then exported and analyzed using Statistical Package for Social Sciences (SPSS) version 22. Descriptive statistics were computed to summarize data and result was presented using tables. Polymerase chain reaction results were analyzed using frequency and percentage. Association between different variables with outcome was analyzed using Fisher exact test. A p-value less than 0.05 was considered as statistically significant.
Discussion
The prevalence of HIV infection in this study was 2.1% (7/340) and comparable to that observed in Brazil (2.01%) [
12]. Our findings were within the global and national plan to reduce MTCT rates to 5% or less by 2015 [
2], (
http://pdf.usaid.gov/pdf_docs/PA00JWM5.pdf). The findings of the current study were higher than studies conducted in Ukraine (1.6%) [
13] and France (1.5%) [
14]. The difference may be due to high coverage of PMTCT interventions in developed countries and limited access, lack of awareness, poor quality of service and others in resource-limited countries like Ethiopia. The prevalence in the current study was however; lower than the study reports from Brazil (11.8%) [
15], Kenya (5%) [
16], Malawi (4.1%) [
17] and Zambia (6.5%) [
18]. The difference in prevalence might be explained due to the difference to ART and PMCT follow up, awareness to HIV, policies, and strategies on HIV control and prevention, methodology and sample size.
Prevalence in this study was lower than those conducted in other parts of Ethiopia including Southern Ethiopia (4.16%) [
19], Bishoftu hospital (4.3%) [
20], North West Ethiopia (10%) [
21], Jimma (10.9%) [
22], Driedawa (15.7%) [
8] and Addis Ababa (32.1%) [
23]. These studies showed higher prevalence, as most of these are retrospective studies their data collection time were ranging from 2005 to 2013, before the implementation of successful intervention strategies like Option B+. Since 2013, Ethiopia is implementing suitable guidelines such as Option B+ where a lifelong antiretroviral treatment is provided to all pregnant and breastfeeding women living with HIV regardless of CD4+ count or WHO clinical stage and Nevirapine to infants in the first 6 weeks of life [
24]. In the current time, HIV infection in exposed infants is decreasing through time due to the overall efforts are done to prevent new HIV infection in infants.
Vertical transmission of HIV in infants is a multi-factorial process, which involves factors associated with HIV-1 transmission. In the present study, the prevalence of HIV was high among infants who did not take antiretroviral prophylaxis at birth (
n = 11, 3.2%), than those who did take ARV prophylaxis at birth (
n = 329, 96.8%) and this was found to be statistically significant (
p < 0.05). Our findings are in line with studies reported from Driedawa [
8], Malawi [
17], Zambia [
18], Nigeria [
25] and Ukraine [
13]. This result is consistent with the widely scientifically accepted fact that ARV in infants decreases the risk of HIV infection [
26].
In addition to infant’s prophylaxis taking maternal PMTCT intervention was statistically significant in decreasing HIV positivity. The finding was agreed with the study done in North West Ethiopia [
21], Amhara [
27], Tanzania [
28], Malawi [
17], Nigeria [
25] and Zambia [
18]. Accordingly, infants who were born to mother who took Option B+ and already on ART had a lower rate of HIV positivity (1.2%) than those who born to mother who didn’t take PMTCT intervention that was (60%). This is supported by the scientifically accepted idea that maternal PMTCT interventions decrease the HIV positivity in exposed infants [
29]. The lower prevalence of HIV (1.2%) in pregnant women was also reported previously in the Amhara region in Ethiopia, which reported high prevalence (10.1%) among the infants born to these mothers [
27]. This was due to delayed HIV diagnosis, inadequate use of antiretroviral therapy and lack of skilled delivery, which promotes mother-to-child transmission of HIV. In the current study the HIV status of HIV positive mothers enrolled for ART was very low (1.2%, 4/333) (Table
1). This is due to the improved coverage at public health facilities responsible for PMTCT and also low number of sample size.
The HIV positivity was high (10.1%) among HIV exposed infants of mothers with the age range of 25–34 which is consistent with a study from Amhara, Ethiopia [
27]. In addition, HIV positivity was high in mothers with CD4
+count >200cell/mm
3compared to mothers with CD4
+count of <200cell/mm
3 in our study. In Zimbabwe [
30] it was observed that maternal CD4
+cell count less than 200 cell/mm
3 was significantly associated with infant HIV positivity. But there are other contradictory to reports from France [
14], Brazil [
15] and Malawi [
17]which show no significant association. In the current study as we observe maternal CD4
+ count of >200cell/mm
3 in mothers that are HIV positive, we can conclude that infection can be transmitted from these mothers to the exposed infants. This may be supported with a conclusion from a study with effective antiretroviral coverage; maternal CD4 count does not affect the HIV positivity [
31]. Our result showed that due to many national and international efforts towards PMTCT and HIV infection, the HIV prevalence among exposed infants is decreasing from time to time.
Conclusion
The overall prevalence of HIV among exposed infants was 2.1%, which is still high prevalence but lower than the Millennium Development Goal (MDG) targets. We observed that, HIV positivity was higher in infants who did not take ARV prophylaxis and whose mothers did not enroll to ART care and follow up and infants of mothers who did not take PMTCT interventions during pregnancy or childbirth. Therefore, in order to eliminate the MTCT, increasing antenatal HIV screening and linking HIV positive pregnant women to PMTCT and ART care and providing appropriate ARV prophylaxis to infants must be done efficiently. Strengthening national monitoring surveillance, coverage, and quality of HIV interventions in mother and child health (MCH) services is important for the PMTCT program.
The prevalence of HIV among infants born from seropositive mothers is reduced to the meaningful number (< 5%) because of the appropriate measures taken for reducing the transmission of HIV from mothers to infants. But, because a significant number of infants from seropositive mothers are still infected. We recommend: Strengthening of the PMTCT of HIV programme, increasing antenatal HIV screening and linking it to care and treatment of HIV positive mothers to obtain zero infant HIV prevalence in the region. Infant prophylaxis and maternal PMTCT interventions should be provided to all exposed infants and mothers based on the guidelines by the health institutions. ART centers in every health institutes and Tigray regional health bureau HIV regional offices should work together to enroll all HIV seropositive mothers to ART care and support which will help to decrease the prevalence of HIV in Tigray even further.
Limitation of the study
We were unable to see the independent effect of variables on the outcome so further studies taking an adequate period of time and on larger sample size is required.
Acknowledgments
We would like to thank Mekelle University, College of Health Sciences, Tigray Regional Health Bureau, and Tigray health research institute for their permission and material support to conduct this study. We would like to extend our gratitude to the data collectors, and Araya Gebreyesus, for their help in Statistical analysis.
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