With a population of 23.3 million and a national HIV prevalence of 4.5%, Cameroon is one of the countries most affected by the human immunodeficiency virus and acquired immune deficiency syndrome (HIV/AIDS) epidemic in West and Central Africa [1] [2] . Accessibility of Prevention of Mother-to-Child Transmission (PMTCT) of HIV services remains low in the country. National data from 2011 showed that while 81% of pregnant women seen in health facilities received HIV testing during antenatal care (ANC), labor and delivery (L & D), and the postpartum period combined (8.4% tested HIV-positive), only 67% of these HIV-positive women received antiretroviral therapy (ART) for PMTCT [3] [4] . Although the Cameroon HIV guidelines in 2011 specified that all HIV-positive exposed infants (HEIs) were eligible for immediate ART, at the time this implementation research was initiated in 2013, only 25% of HEIs were provided antiretroviral (ARV) prophylaxis at birth, 9.3% had an HIV deoxyribonucleic acid polymerase chain reaction (DNA PCR) test at 8 weeks of age (7.1% infants testing HIV-positive), and approximately 3% of those HIV infected were initiated on lifelong ART [4] . Consequently, HIV-related deaths have contributed to a decrease in life expectancy in Cameroon from 54 years in 1990 to 51.5 years in 2010, with 10.1% of maternal deaths estimated to be HIV-related [5] [6] .

In support of the national HIV/AIDS program in Cameroon, the Cameroon Baptist Convention Health Services (CBCHS), in collaboration with the Elizabeth Glaser Pediatric AIDS Foundation (EGPAF), the Centers for Disease Control and Prevention (CDC), and the Cameroon Ministry of Public Health (MOPH), initiated scaling up implementation of HIV testing services (HTS), care and treatment, and PMTCT services with the aim to reduce HIV burden among these vulnerable populations [7] . The PMTCT program has evolved from the use of single-dose nevirapine (sdNVP) in 2000 to implementation of the World Health Organization (WHO) Option A regimen for pregnant and breastfeeding women in 2010 [7] [8] . For HIV-infected pregnant women who were not eligible for lifelong ART based on CD4 count or clinical staging, Option A consisted of antepartum twice-daily zidovudine (ZDV) to HIV-infected pregnant women starting at 14 weeks of gestation and continued throughout pregnancy. At the onset of labor, sdNVP was administered with the initiation of twice daily ZDV and lamivudine (3TC) for seven days postpartum. HIV-exposed infant (HEI) prophylaxis involved neviparine (NVP) syrup from birth until one week after cessation of breastfeeding or for six weeks postpartum if not breastfeeding [9] [10] . In 2010, the government of Cameroon developed a national plan for the elimination of mother-to-child transmission of HIV (eMTCT) to align with the global eMTCT plan to reduce new pediatric HIV infections and decrease the MTCT rate to less than 5% by 2015 [11] [12] .

In 2012, Cameroon’s MOPH decided to implement Option B+ (life-long ART for pregnant and breastfeeding women regardless of CD4 count) nationwide using a phased approach to reach these goals [11] . With funding from the U.S. President’s Emergency Plan For AIDS Relief (PEPFAR) through CDC, CBCHS piloted a rollout of PMTCT Option B+ in the Northwest and Southwest regions of the country. The aim of this study was to evaluate outcomes and effectiveness of PMTCT Option B+ service at 12 months postpartum in order to facilitate national scale-up by the MOPH. A second evaluation will describe 24 months postpartum outcomes.

Figure 1 shows the flow chart of participants enrolled in the study. Of 11,313 pregnant or breastfeeding women who attended maternal and child health (MCH) services in the 22 study facilities, 680 (6%) were HIV-positive and not on ART or ARV prophylaxis. Of these 680 eligible participants, 669 (98%) initiated Option B+; this included three clients who initially accepted ART only during pregnancy but later changed to lifelong ART during the course of the pregnancy. All 669 participants who initiated Option B+ were enrolled in the study.

Historically, PMTCT coverage and ART retention along the PMTCT cascade have been poor in Cameroon [4] . UNAIDS reported a 6 weeks MTCT rate of 5.2% in Cameroon, which is higher than the global eMTCT targets of less than 2% and 5% at 6 weeks and after cessation of breastfeeding respectively [13] . To achieve these targets, ART uptake and maternal retention on ART are essential. Early implementers of Option B+ have reported high ART uptake, yet many countries have struggled with maternal retention [14] [15] . In this evaluation, early retention at 6 months after ART initiation was high at 90% and then declined at 12 months after ART initiation to 79%. The 12 months ART retention rate was high when compared to 60% from a nationwide survey of Cameroon’s adult ART program in 2014 [16] . Among women in Option B+ programs, the 6 months retention rate in Cameroon was higher than the rate seen in Uganda and the Democratic Republic of Congo (DRC), while the 12 months retention was similar to data from Malawi Option B+ program [14] [17] [18] . To identify effective strategies to improve maternal retention, it was important to first understand which patients were at highest risk of LTFU. Similar to results from Malawi [17] and Ethiopia [15] , this study found that clients with higher transport cost to the facility were twice as likely to become LTFU at 12 months compared to those with lower transport cost. To minimize LTFU after ART initiation and after delivery, we used appointment diaries and peer educators throughout the

duration of the study, to closely monitor clients with missed appointments and to re-engage defaulters and patients with more than one month since the last ART refills. We did not experience high LTFU immediately after ART initiation and among women who initiated Option B+ while breastfeeding. Compared to the Cameroon adult ART retention data, our study suggested that women involved in the Option B+ program had a better 12 months ART retention, and this may be due to the interventions in place. However, this evaluation was limited to only 2 regions of Cameroon and was not nationwide as the Cameroon adult ART retention data.

In Malawi, 6 months retention data demonstrated that women initiating ART during pregnancy were five times more likely not to return to the clinic after they initiated ART compared to non-pregnant women (OR: 5.0, 95% CI 4.2 - 6.1) and those who started Option B+ while breastfeeding were twice as likely to miss their first follow up visit compared to women who initiated during ANC [17] .

During this evaluation, CD4 testing was used since the Cameroon national guidelines on management of HIV recommended CD4 testing at baseline and every 6 months while on ART. Despite cost subsidies and laboratory sample transportation systems to improve uptake of laboratory tests, we noted a drop in CD4 testing uptake greater than 50% at 6 months and almost 90% at 12 months after ART initiation. Reliance on ongoing CD4 monitoring for PMTCT Option B+ for a test and start approach may not be feasible in the Cameroon setting.

Some of the challenges noted in this evaluation included systemic barriers (such as long waiting times for sample collection, stock out of reagents, frequent break down of equipment) and distance to testing site; these have been described in other countries as well [9] [10] . The results of this study stressed the importance of addressing programmatic challenges related to laboratory equipment and supply chain system of reagents and other commodities to ensure high uptake of routine laboratory testing.

In Cameroon, HIV is a large contributor to maternal mortality rates. A 2012 study attributed 10% of pregnancy-related deaths to HIV [6] . However, in this current study which took place in an Option B+ setting, a mortality rate of 2% was found among enrolled women at 12 months post-ART initiation; this is similar to 1.7% found in a study in Malawi [17] and 2.6% found 6 months after initiation of Option B in the Cameroon DREAM study [19] .

Rates of infant NVP uptake after birth, HIV DNA PCR testing at 6 to 8 weeks of life, and MTCT at 6 weeks captured by PCR were similar to those found in Malawi, where 95% of HEIs received ARV prophylaxis (NVP) after birth, 82% received a DNA PCR test at 6 to 8 weeks of life, and 2.6% tested positive [20] . We put systems in place to track defaulters and improve retention along the PMTCT cascade and early infant diagnosis (EID) uptake using community workers.

The uptake of EID of 95.7% and the HIV transmission rate among infants tested at 8 weeks of 2.4% reported in this study are 3 times better than the 2014 overall country EID uptake of 24% and MTCT rate at 6 weeks of 7%, identified shortly before Option B+ was implemented nationwide in Cameroon [21] The 2015 estimated uptake of EID at 8 weeks was 30% while the HIV transmission rate among infants tested at 6 weeks was 5% [22] .

This evaluation follows a large prospective cohort of mother-infant pairs across 22 busy PMTCT sites predominantly in semi-urban and rural areas of Cameroon. The descriptive evaluation of the outcomes of mother-infant pairs was not designed as an experimental study that would allow causal inferences to be made. The selection strategy of participating health facilities and eligibility of participants may limit the generalizability of findings and the ability to be a model for a complete Option B+ policy. Because many HEIs were still breastfeeding at the time of the 6 weeks HIV DNA PCR testing, our results may underestimate final HIV rates in this cohort after cessation of breastfeeding. Additionally, we only know the HIV status of HEIs who were retained during the reporting period; HEIs who were not retained might have been more likely to become HIV infected or to have died. Final outcomes of enrolled HEIs are not included since many had not yet reached 18 months of age at the time of analysis. However, HEIs continued to be followed, and the HIV transmission rate among those tested at 24 months of age and/or after cessation of breastfeeding will be addressed in a subsequent analysis.

We describe the outcome evaluation of early implementation of PMTCT Option B+ in Cameroon. Our data demonstrate that it is possible to achieve high 12 months ART retention rate among pregnant and breastfeeding women who start ART after they are diagnosed with HIV. In addition, reduction of MTCT was also achieved. Longer-term ART retention, infant mortality, and HIV transmission rate among HEIs after cessation of breastfeeding need further evaluation.

This publication was made possible by support from the President's Emergency Plan for AIDS Relief (PEPFAR) through cooperative agreement number 5U2GGH00352 from the Centers for Disease Control and Prevention (CDC), Division of Global AIDS Tuberculosis (DGHT). The findings and conclusions in this report are those of the author(s) and do not necessarily represent the official position of the Centers for Disease Control and Prevention. We would like to thank the University of North Carolina (UNC) for their assistance in the development of the Epi Info database used for data collection. We recognize colleagues at the Cameroon MOPH for their steadfast leadership and tireless work towards eliminating new HIV infections in children and keeping mothers healthy. We gratefully acknowledge Surbhi Modi, Team Lead for the Maternal and Infant HIV Team, Division of Global HIV/TB, Centers for Disease Control & Prevention (CDC) and Nicholas Gaffga, Maternal and Infant HIV Team, Division of Global HIV/TB, Centers for Disease Control & Prevention (CDC) for their technical review and contributions to the manuscript. We recognize management and staff of the 22 health institutions who participated in the evaluation for demonstrating exemplary technical leadership and collaboration. Finally, we wish to recognize the mothers living with HIV who participated in our study and were central to our collective successes in keeping the mother-infant pair healthy.

The authors declare no conflicts of interest regarding the publication of this paper.

Muffih, P.T., Tshimwanga, E.K., Abutu, A., Abongwa, L.E., Awa, J.C., Atanga, P.N., Desembuin, F., Khan, E.M., Bonje, K.E., Emmanuel, N., Chimoun, E.F.T., Welty, T., Fosah, G.T., Lim, J., Duncan, D., Petit, L., Tene, G., Mosoko, J. and Bolu, O. (2018) Outcome Evaluation of Early Implementation of Option B+ in Cameroon: A Prospective Cohort Observational Survey in the Northwest and Southwest Regions. World Journal of AIDS, 8, 90-104. https://doi.org/10.4236/wja.2018.83008