Applied Epidemiology in Cambodia.

In meeting the Master of Philosophy in Applied Epidemiology (MAE)'s, I completed two of my core projects at the Institute Pasteur of Cambodia (IPC), a non-governmental organization. The other two core projects I completed at the Ministry of Health's Cambodian Communicable Disease Control Department (CCDC), where I was later deployed to support Coronavirus Disease 2019 (COVID-19) contact tracing and surveillance. In this thesis, I demonstrate how I met the core competencies of the MAE program. In late November and early December 2019, a provincial health department notified CCDC about what they called a food poisoning event that had affected more than 200 people, and resulted in two deaths in a residential facility in a province of Cambodia. We conducted a case-control study. We found a strong association between eating cucumbers and illness. However, laboratory analysis failed to detect a causative agent. Toxicology testing was not conducted, and therefore we were unable to rule out contamination of the cucumbers. This project is described in chapter two, "An outbreak of unknown etiology associated with fresh cucumbers in a residential facility in Cambodia, 2019". We aimed at describing how malaria has evolved spatially from 2006 to 2019. We undertook a secondary analysis of existing malaria data from all public health facilities in Cambodia between 2006 and 2019 in combination with metadata. Overall, incidence fluctuated between 1.5 and 7.4 cases/1000 inhabitants per year. Malaria clusters were detected in seven northern provinces, along borders. We recommended that interventions aimed at preventing new infections of Plasmodium vivax and relapses should be prioritized. All confirmed malaria cases should be reported to Health Management Information System to avoid misleading trends. This project is detailed in chapter three, "Malaria in Cambodia: retrospective analysis of a changing epidemiology 2006-2019." I implemented and evaluated the RAI2 surveillance system as part of activities associated with a funded malaria project. Nine attributes, adapted from the US CDC guideline 2001, were used to assess the performance of the system. Usefulness was described based on the outcome of the evaluation of the other eight attributes. Simplicity, flexibility, acceptability, and stability were assessed using a short online survey with health center staff. Sensitivity, positive predictive value, data quality, and timeliness were assessed using document review and data from the RAI2 surveillance system. Findings suggested that the RAI2 surveillance system was simple, flexible, stable, timely but did not meet its primary objective. We recommended that the RAI2 surveillance system should be integrated into the national malaria information system and moved to be a real-time data collection. Additional exposure variables should be captured. I placed this project in chapter four, "Using Kobo Toolbox as a malaria project-based surveillance system in Cambodia: surveillance evaluation." My final project was to estimate the proportion of COVID-19 cases that were asymptomatic and understand how the asymptomatic transmission may occur. I analyzed data from 22 cases as part of a cluster of returned travelers, with what was believed to be a common exposure site. Their 491 uninfected contacts and ten infected contacts were also included in the analysis. The findings suggested asymptomatic cases made up a larger proportion of total cases within the cluster. This project is described in chapter five, "Coronavirus Disease 2019 asymptomatic transmission: A cluster review in Cambodia, 2020." Finally, other required activities presented in this thesis include an oral presentation, a scientific manuscript submitted to a peer-review journal, a literature review, a summary for a layperson, lessons learned from the field, and teaching

Using Risk-Tracing Snowball Approach to Increase HIV Case Detection Among High-Risk Populations in Cambodia: An Intervention Study

Background: Early HIV diagnosis and initiation onto antiretroviral therapy may prevent ongoing spread of HIV. Risk Tracing Snowball Approach (RTSA) has been shown to be effective in detecting new HIV cases in other settings. The main objective of this study is to evaluate the effectiveness of RTSA in increasing the rate of newly identified HIV cases among high-risk populations. Our second objective was to evaluate the effectiveness of RTSA, as compared to the walk-in group, in increasing the number of HIV tests and early case detection. Methods: This study was conducted from April 1 to September 30, 2016 at two NGO clinics in Phnom Penh, Cambodia. Respondent driven sampling method was adapted to develop RTSA to reach high-risk populations, including key populations and the general population who have social connections with key populations. Bivariate and multivariate logistic regression analyses were conducted. Results: During the implementation period, 721 clients walked in for HIV testing (walk-in group), and all were invited to be seeds. Of the invited clients, 36.6% agreed to serve as seeds. Throughout the implementation, 6195 coupons were distributed to seeds or recruiters, and resulted in 1572 clients visiting the two clinics with coupons (RTSA group), for a coupon return rate of 25.3%. The rate of newly identified HIV cases among the RTSA group was significantly lower compared to that in walk-in group. However, the highest number of newly identified HIV cases was found during the implementation period, compared to both pre- and post-implementation period. Although statistically not significant, the mean CD4 count of newly identified HIV cases detected through RTSA was almost 200 cells/mm3 higher than that in the walk-in group. Conclusions: Although the rate of newly identified HIV cases among the RTSA group was lower than that in the walk-in group, the inclusion of RTSA in addition to the traditional walk-in method boosted new HIV case detection in the two participating clinics. A higher mean CD4 count for the RTSA group may reveal that RTSA may be able to detect HIV cases earlier than the traditional walk-in approach. Further research is needed to understand whether RTSA is a cost-effective intervention to prevent ongoing spread of the HIV among high-risk populations in Cambodia

Men Who Have Sex with Men in Cambodia: Population Size, HIV Risky Behaviors, and HIV Prevalence

Background: Men who have sex with men (MSM) constitute a significant proportion of HIV key populations in Cambodia. We conducted this study to estimate the national population size, assess HIV-related risk behaviors, and determine HIV prevalence among MSM in Cambodia. Methods: This research was conducted in 2014 in 12 study sites in Cambodia. MSM size estimation was performed using capture-recapture method with data collected in two time points within an 18-day interval. To assess HIV risk behaviors, a total of 838 MSM were randomly selected for face-to-face interviews during the capture round. A separate survey using a time location sampling approach was conducted to estimate HIV prevalence. Results: The estimated size of MSM in Cambodia was 31,000. Of the total, 52.0%were in urban areas; 89.0% were sexually active; and 65.0% were reachable MSM. Phnom Penh had the largest MSM population. More than two-thirds (69.4%) of MSM reported always using condoms in the last month. The majority (71.6%) of them reported receiving HIV information, while 66.6% and 49.3% reported having been tested for HIV and sexual transmitted infections (STI), respectively in the past six months. Eight percent reported having at least one STI symptom in the past 12 months; of whom, 93.6% reported receiving treatment for the most recent symptoms.HIV prevalence among MSM in this study was 2.3%. The highest HIV prevalence was found in Siem Reap (5.9%) and Phnom Penh (3.0%). The prevalence was higher among MSM aged 25 years or older (4.6%) and those with lower formal education level (4.5%). MSM who reported sex work being their main job had the highest HIV prevalence (17.2%) compared to those in other occupation categories who had a prevalence ranging from 1.0% to 4.7%. Conclusions: With a population size of approximately 31,000, MSM in Cambodia remain at high HIV risk due to their engagement in multiple risky sexual behaviors. Continued efforts to prevent, manage, and treat HIV in this population are essential to eliminate new HIV infections by 2020. Considerations of sub-groups are imperative to better inform resource allocation to refine the efficacy of intervention programs for this population

HIV Prevalence and Factors Associated with HIV Infection Among Transgender Women in Cambodia: Results from a National Integrated Biological and Behavioral Survey

Objective To examine factors associated with HIV infection among transgender women in Cambodia. Design Cross-sectional study. Settings HIV high-burden sites including the capital city and 12 provinces. Participants This study included 1375 sexually active transgender women with a mean age of 25.9 years (SD 7.1), recruited by using respondent-driven sampling for structured questionnaire interviews and rapid finger-prick HIV testing. Primary outcome measure HIV infection detected by using Determine antibody test. Results HIV prevalence among this population was 5.9%. After adjustment for other covariates, participants living in urban areas were twice as likely to be HIV infected as those living in rural areas. Participants with primary education were 1.7 times as likely to be infected compared with those with high school education. HIV infection increased with age; compared with those aged 18–24 years, the odds of being HIV infected were twice as high among transgender women aged 25–34 years and 2.8 times higher among those aged ≥35 years. Self-injection of gender affirming hormones was associated with a fourfold increase in the odds of HIV infection. A history of genital sores over the previous 12 months increased the odds of HIV infection by threefold. Transgender women with stronger feminine identity, dressing as a woman all the time, were twice as likely to be HIV infected compared with those who did not dress as a woman all the time. Having never used online services developed for transgender women in the past six months was also associated with higher odds of being HIV infected. Conclusions Transgender women in Cambodia are at high risk of HIV. To achieve the goal of eliminating HIV in Cambodia, effective combination prevention strategies addressing the above risk factors among transgender women should be strengthened

HIV prevalence, risky behaviors, and discrimination experiences among transgender women in Cambodia: descriptive findings from a national integrated biological and behavioral survey

Background: Transgender people are disproportionately affected by HIV. Despite their high vulnerability to HIV, lack of adequate epidemiological and surveillance data related to this population in many countries prevents provision of appropriate services. This paper summarizes descriptive findings from a national integrated biological and behavioral survey and discusses policy implications of the findings on HIV prevention among transgender women in Cambodia. Methods: This cross-sectional study was conducted between December 2015 and February 2016. Participants were recruited from 20 sites in the capital city and 12 provinces of Cambodia using Respondent Driven Sampling (RDS) method. Behavioral data were collected through structured questionnaire interviews, and rapid finger-prick HIV testing was performed. Descriptive data analyses were conducted using STATA. Results: This study included 1,375 transgender women with a mean age of 25.9 years (SD = 7.1). The overall prevalence of HIV was 5.9%. The prevalence of HIV was significantly higher among urban participants compared to their rural counterparts (6.5 vs. 2.6%, p = 0.02). Almost one in five (19.6%) had never been tested for HIV prior to the study. Overall, 45.0% reported ever using gender affirming hormones. More than one-third (39.1%) reported not using condoms in their last sex, 29.8% had engaged in sex in exchange for money/gifts, and 14.0% reported that they had experienced at least one symptom of sexually transmitted infections (STI) in the past year. About one in ten (10.1%) reported having used some form of amphetamine-type stimulant drugs, while 6.5% reported having sex during or after using illicit drugs. A significant number of participants experienced sexual abuse (39.2%), losing a job (24.3%), or physical abuse (23.6%) because of their transgender identity. In addition, 82.9 and 88.9% would be willing to use the HIV self-test and pre-exposure prophylaxis (PrEP), respectively, if they become available. Conclusions: The high prevalence of HIV, STI, and related risk behaviors among transgender women in Cambodia is of great concern, suggesting an urgent need to further expand tailored prevention interventions for this key population focusing on individual, social, and structural drivers of HIV. HIV self-test and PrEP should be explored as a priority

Factors Associated with Condom Use with Non-Commercial Partners Among Sexually-Active Transgender Women in Cambodia: Findings From a National Survey Using Respondent-Driven Sampling.

BACKGROUND: Globally, the prevalence of HIV among transgender women is much higher than that of the general adult population. This can be explained by the persistently low rate of consistent condom use among this population. This study was therefore conducted to explore factors associated with consistent condom use among sexually-active transgender women in Cambodia, specifically with their non-commercial partners. METHODS: Data used for this study were collected as part of the National Integrated Biological and Behavioral Survey 2016. Participants were recruited from the capital city of Phnom Penh and 12 other provinces with high burden of HIV using the Respondent-Driven Sampling (RDS) method. Face-to-face interviews were conducted using a structured questionnaire. Weighted multivariate logistic regression analysis was conducted to explore independent factors associated with consistent condom use. RESULTS: This study included 1202 transgender women who reported having anal sex with at least one male partner not in exchange for money or gifts in the past three months. The mean age of the participants was 26.0 (SD = 7.0) years. Of the total, 41.5% reported always using condoms with male non-commercial partners in the past three months. After adjustment, the likelihood of consistent condom use was significantly higher among participants who resided in an urban community (AOR = 1.7, 95% CI = 1.1-2.6), had attained at least 10 years of formal education (AOR = 1.8, 95% CI = 1.2-2.7), perceived that they were likely or very likely to be HIV infected (AOR = 2.9, 95% CI = 2.0-4.1), reported drinking alcohol two to three times per week (AOR = 3.1, 95% CI = 1.1-8.3), reported using amphetamine-type stimulants (AOR = 1.9, 95% = 1.1-3.8) or other drugs (AOR = 7.6, 95% CI = 1.5-39.5), and reported inconsistent condom use with male commercial partners in the past three months (AOR = 4.3, 95% CI = 1.8-10.4) compared to that of their respective reference group. CONCLUSIONS: This study confirms the low rates of condom use, particularly in non-commercial relationship, among transgender women in Cambodia. To address these concerns, efforts towards education about effects of multiple, concurrent relationships, and inconsistent condom use should be reinforced among transgender women

Access to Community-Based HIV Services Among Transgender Women in Cambodia: Findings from a National Survey.

BACKGROUND: Globally, the prevalence of HIV among transgender women is more than 40 times higher than the prevalence in the general reproductive-age adults. They also face intersecting barriers to health, social, and legal services due to their hidden and stigmatized nature. Despite the particular needs, data regarding the access to services among transgender populations is scant globally. This study aims to identify characteristics of transgender women in Cambodia that may determine their accessibility to community-based HIV services. METHODS: In the National Biological and Behavioral Survey 2016, a structured questionnaire was used for face-to-face interviews with 1375 sexually active transgender women recruited from the capital city and 12 other provinces using the Respondent-Driven Sampling method. Weighted multivariate regression analysis was conducted to explore factors associated with access to community-based HIV services. RESULTS: The mean age of the participants was 25.8 years (SD = 7.1), and 45.0% reported having received at least one community-based HIV service in the past three months. Compared to participants who reported not having been reached by any community-based HIV programs, participants who reported having been reached by the programs were significantly more likely to reside in an urban setting (AOR = 1.41, 95% CI = 1.01-1.96), to have used gender-affirming hormones (AOR = 1.50, 95% CI = 1.17-1.92), to have been tested for HIV in the past six months (AOR = 7.42, 95% CI = 5.78-9.53), and to have been arrested by police or other authorities because of their transgender identity (AOR = 1.55, 95% CI = 1.03-2.33). Participants who reported having been reached by community-based HIV programs were significantly less likely to report being in a receptive role (AOR = 0.34, 95% CI = 0.15-0.82), to use condoms consistently with non-commercial male partners (AOR = 0.72, 95% CI = 0.55-0.94), and to perceive that their co-workers were not supportive regarding their transgender identity (AOR = 0.57, 95% CI = 0.44-0.98). CONCLUSIONS: Despite the extensive expansion of community-based HIV programs, less than half of transgender women in this national survey had access to the services. Innovative strategies and culturally sensitive interventions should be put in place to reach and respond to the needs of sub-groups of transgender women who are less likely to be reached by the existing traditional approaches

Acceptability Study on HIV Self-Testing among Transgender Women, Men Who Have Sex with Men, and Female Entertainment Workers in Cambodia: A Qualitative Analysis

Background: In Cambodia, HIV prevalence is high while HIV testing rates remain low among transgender women (TG women), men who have sex with men (MSM), and female entertainment workers (FEW). Introducing self-testing for HIV to these key populations (KPs) could potentially overcome the under-diagnosis of HIV and significantly increase testing rates and receipt of the results, and thus could decrease transmission. Therefore, this study aimed to determine the acceptability of HIV self-testing (HIVST) among these three categories of KPs. Methods: This study was conducted through focus group discussions (FGDs) with TG women, MSM, and FEW in Phnom Penh city, Kampong Cham, Battambang, and Siem Reap provinces of Cambodia. Convenience sampling was used to recruit the participants. Two FGDs (six participants in each FGD) were conducted in each target group in each study site, totaling 24 FGDs (144 participants). Thematic analysis was performed to identify common or divergent patterns across the target groups. Results: Almost all participants among the three groups (TG women, MSM, and FEW) had not heard about HIVST, but all of them expressed willingness to try it. They perceived HIVST as confidential, convenient, time-saving, and high-tech. Barriers to obtaining HIVST included cost, access, administration technique, embarrassment, and fear of pain. The majority preferred counseling before and after testing. Conclusions: Participants showed high willingness to use and acceptability of HIVST due to its confidentiality/privacy and convenience even if it is not linked to a confirmatory test or care and treatment. Notwithstanding, to increase HIVST, the target groups would need affordable self-test kits, education about how to perform HIVST and read results, assurance about accuracy and reliability of HIVST, and provision of post-test counseling and facilitation of linkage to care and treatment

Scaling-up integrated type-2 diabetes and hypertension care in Cambodia: what are the barriers to health system performance?

BackgroundNon-communicable diseases (NCDs) such as type-2 diabetes (T2D) and hypertension (HTN) pose a massive burden on health systems, especially in low- and middle-income countries. In Cambodia, to tackle this issue, the government and partners have introduced several limited interventions to ensure service availability. However, scaling-up these health system interventions is needed to ensure universal supply and access to NCDs care for Cambodians. This study aims to explore the macro-level barriers of the health system that have impeded the scaling-up of integrated T2D and HTN care in Cambodia.MethodsUsing qualitative research design comprised an articulation between (i) semi-structured interviews (33 key informant interviews and 14 focus group discussions), (ii) a review of the National Strategic Plan and policy documents related to NCD/T2D/HTN care using qualitative document analysis, and (iii) direct field observation to gain an overview into health system factors. We used a health system dynamic framework to map macro-level barriers to the health system elements in thematic content analysis.ResultsScaling-up the T2D and HTN care was impeded by the major macro-level barriers of the health system including weak leadership and governance, resource constraints (dominantly financial resources), and poor arrangement of the current health service delivery. These were the result of the complex interaction of the health system elements including the absence of a roadmap as a strategic plan for the NCD approach in health service delivery, limited government investment in NCDs, lack of collaboration between key actors, limited competency of healthcare workers due to insufficient training and lack of supporting resources, mis-match the demand and supply of medicine, and absence of local data to generate evidence-based for the decision-making.ConclusionThe health system plays a vital role in responding to the disease burden through the implementation and scale-up of health system interventions. To respond to barriers across the entire health system and the inter-relatedness of each element, and to gear toward the outcome and goals of the health system for a (cost-)effective scale-up of integrated T2D and HTN care, key strategic priorities are: (1) Cultivating leadership and governance, (2) Revitalizing the health service delivery, (3) Addressing resource constraints, and (4) Renovating the social protection schemes