Disparities in Dolutegravir Uptake Affecting Females of Reproductive Age With HIV in Low- and Middle-Income Countries After Initial Concerns About Teratogenicity : An Observational Study.

BACKGROUND: The transition to dolutegravir-containing antiretroviral therapy (ART) in low- and middle-income countries (LMICs) was complicated by an initial safety signal in May 2018 suggesting that exposure to dolutegravir at conception was possibly associated with infant neural tube defects. On the basis of additional evidence, in July 2019, the World Health Organization recommended dolutegravir for all adults and adolescents living with HIV. OBJECTIVE: To describe dolutegravir uptake and disparities by sex and age group in LMICs. DESIGN: Observational cohort study. SETTING: 87 sites that began using dolutegravir in 11 LMICs in the Asia-Pacific; Caribbean, Central and South America network for HIV epidemiology (CCASAnet); and sub-Saharan African regions of the International epidemiology Databases to Evaluate AIDS (IeDEA) consortium. PATIENTS: 134 672 patients aged 16 years or older who received HIV care from January 2017 through March 2020. MEASUREMENTS: Sex, age group, and dolutegravir uptake (that is, newly initiating ART with dolutegravir or switching to dolutegravir from another regimen). RESULTS: Differences in dolutegravir uptake among females of reproductive age (16 to 49 years) emerged after the safety signal. By the end of follow-up, the cumulative incidence of dolutegravir uptake among females 16 to 49 years old was 29.4% (95% CI, 29.0% to 29.7%) compared with 57.7% (CI, 57.2% to 58.3%) among males 16 to 49 years old. This disparity was greater in countries that began implementing dolutegravir before the safety signal and initially had highly restrictive policies versus countries with a later rollout. Dolutegravir uptake was similar among females and males aged 50 years or older. LIMITATION: Follow-up was limited to 6 to 8 months after international guidelines recommended expanding access to dolutegravir. CONCLUSION: Substantial disparities in dolutegravir uptake affecting females of reproductive age through early 2020 are documented. Although this disparity was anticipated because of country-level restrictions on access, the results highlight its extent and initial persistence. PRIMARY FUNDING SOURCE: National Institutes of Health.

Retention in care and viral suppression in the PMTCT continuum at a large referral facility in western Kenya.

Medical records of pregnant and postpartum women living with HIV and their infants attending a large referral facility in Kenya from 2015 to 2019 were analyzed to identify characteristics associated with retention in care and viral suppression. Women were stratified based on the timing of HIV care enrollment: known HIV-positive (KHP; enrolled pre-pregnancy) and newly HIV-positive (NHP; enrolled during pregnancy). Associations with retention at 18 months postpartum and viral suppression (< 1000 copies/mL) were determined. Among 856 women (20% NHP), retention was 83% for KHPs and 53% for NHPs. Viral suppression was 88% for KHPs and 93% for NHPs, but 19% of women were missing viral load results. In a competing risk model, viral suppression increased by 18% for each additional year of age but was not associated with other factors. Overall, 1.9% of 698 infants with ≥ 1 HIV test result were HIV-positive. Tailored interventions are needed to promote retention and viral load testing, particularly for NHPs, in the PMTCT continuum.

5-Aryltetrazoles from Direct C-H Arylation with Aryl Bromides.

A mild, direct C-H arylation of 1-substituted tetrazoles to 5-aryltetrazoles is developed using a Pd/Cu cocatalytic system with readily available aryl bromides. The methodology avoids late-stage usage of azides and tolerates a wide range of functionalities.

2,2,2-Trifluoroethoxy Aromatic Heterocycles: Hydrolytically Stable Alternatives to Heteroaryl Chlorides.

Herein we describe the 2,2,2-trifluoroethoxy group as an alternative leaving group for hydrolytically unstable heteroaryl chlorides. This group provides improved shelf stability by years while maintaining reactivity toward nucleophiles in SNAr reactions. A highlighted trifluoroethyl ether was shown to be tolerant to aqueous Suzuki conditions, permitting sequential Suzuki/SNAr processes inaccessible to the heterocyclic chlorides. The strategic use of trifluoroethyl ethers enables storage of otherwise unstable heterocyclic chlorides and limits costly decomposition.

Synthesis of Pyridopyrazine-1,6-dione γ-Secretase Modulators via Selective 4-Methylimidazole N1-Buchwald Arylation.

An efficient synthesis of pyridopyrazine-1,6-dione γ-secretase modulators (GSMs) is described. Our route features the construction of a crystalline lactone intermediate via a selective palladium-catalyzed 4-methylimidazole N1-arylation using the Buchwald Xantphos Pd G4 precatalyst, which does not require a preactivation step. The weak inorganic base KHCO3 was employed to minimize saponification of a particularly sensitive lactone substrate. Additional key transformations include DABAL-Me3-mediated lactone aminolysis and a mild TBD/ethyl trifluoroacetate mediated lactam ring closure to afford a representative GSM in high yield.

Protocol for the Direct Conversion of Lactones to Lactams Mediated by 1,5,7-Triazabicyclo[4.4.0]dec-5-ene: Synthesis of Pyridopyrazine-1,6-diones.

We present an operationally simple lactone-to-lactam transformation utilizing diverse amine nucleophiles. The key steps of amidation, alcohol activation, and cyclization are all mediated by one reagent (TBD) in a single vessel at room temperature. We illustrate the convenience of this protocol by synthesizing a wide range of N-alkyl, N-aryl, and N-hetereoaryl pyridopyrazine-1,6-diones, an important class of medicinally significant lactams. Furthermore, the reported methodology can be applied to the synthesis of milligram to hundred gram quantities of pyridopyrazine-1,6-diones without the use of specialized equipment.

Luteinizing Hormone Causes Phosphorylation and Activation of the cGMP Phosphodiesterase PDE5 in Rat Ovarian Follicles, Contributing, Together with PDE1 Activity, to the Resumption of Meiosis.

The meiotic cell cycle of mammalian oocytes in preovulatory follicles is held in prophase arrest by diffusion of cGMP from the surrounding granulosa cells into the oocyte. Luteinizing hormone (LH) then releases meiotic arrest by lowering cGMP in the granulosa cells. The LH-induced reduction of cGMP is caused in part by a decrease in guanylyl cyclase activity, but the observation that the cGMP phosphodiesterase PDE5 is phosphorylated during LH signaling suggests that an increase in PDE5 activity could also contribute. To investigate this idea, we measured cGMP-hydrolytic activity in rat ovarian follicles. Basal activity was due primarily to PDE1A and PDE5, and LH increased PDE5 activity. The increase in PDE5 activity was accompanied by phosphorylation of PDE5 at serine 92, a protein kinase A/G consensus site. Both the phosphorylation and the increase in activity were promoted by elevating cAMP and opposed by inhibiting protein kinase A, supporting the hypothesis that LH activates PDE5 by stimulating its phosphorylation by protein kinase A. Inhibition of PDE5 activity partially suppressed LH-induced meiotic resumption as indicated by nuclear envelope breakdown, but inhibition of both PDE5 and PDE1 activities was needed to completely inhibit this response. These results show that activities of both PDE5 and PDE1 contribute to the LH-induced resumption of meiosis in rat oocytes, and that phosphorylation and activation of PDE5 is a regulatory mechanism.

Discovery of indole-derived pyridopyrazine-1,6-dione γ-secretase modulators that target presenilin.

Herein we describe design strategies that led to the discovery of novel pyridopyrazine-1,6-dione γ-secretase modulators (GSMs) incorporating an indole motif as a heterocyclic replacement for a naphthyl moiety that was present in the original lead 9. Tactics involving parallel medicinal chemistry and in situ monomer synthesis to prepare focused libraries are discussed. Optimized indole GSM 29 exhibited good alignment of in vitro potency and physicochemical properties, and moderate reduction of brain Aß42 was achieved in a rat efficacy model when dosed orally at 30mg/kg. Labeling experiments using a clickable, indole-derived GSM photoaffinity probe demonstrated that this series binds to the presenilin N-terminal fragment (PS1-NTF) of the γ-secretase complex.

Discovery of Clinical Candidate PF-06648671: A Potent γ-Secretase Modulator for the Treatment of Alzheimer's Disease.

Herein, we describe the design and synthesis of γ-secretase modulator (GSM) clinical candidate PF-06648671 (22) for the treatment of Alzheimer's disease. A key component of the design involved a 2,5-cis-tetrahydrofuran (THF) linker to impart conformational rigidity and lock the compound into a putative bioactive conformation. This effort was guided using a pharmacophore model since crystallographic information was not available for the membrane-bound γ-secretase protein complex at the time of this work. PF-06648671 achieved excellent alignment of whole cell in vitro potency (Aß42 IC50 = 9.8 nM) and absorption, distribution, metabolism, and excretion (ADME) parameters. This resulted in favorable in vivo pharmacokinetic (PK) profile in preclinical species, and PF-06648671 achieved a human PK profile suitable for once-a-day dosing. Furthermore, PF-06648671 was found to have favorable brain availability in rodent, which translated into excellent central exposure in human and robust reduction of amyloid ß (Aß) 42 in cerebrospinal fluid (CSF).

Preswitch Regimens Influence the Rate of Weight Gain After Switch to Tenofovir Disoproxil Fumarate, Lamivudine, and Dolutegravir (TLD): Study From an East African Cohort.

Background: Switching from non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens to dolutegravir (DTG) has been associated with greater weight gain. Methods: We conducted our analysis using a longitudinal cohort of people with HIV (PWH) in Western Kenya. We evaluated changes in the rate of weight gain among treatment-experienced, virally suppressed PWH who switched from NNRTI to tenofovir disoproxil fumarate, lamivudine, and dolutegravir (TLD). We modeled the weights pre- and postswitch using a 2-phase model with linear trend preswitch and an inverted exponential function postswitch. We estimated an 18-month excess weight gain by comparing the projected weight with that expected using the preswitch rate. Results: A total of 18 662 individuals were included in our analysis, with 55% switching from efavirenz (EFV) and 45% from nevirapine (NVP). Of the studied individuals, 51% were female, and the median age and body mass index (BMI) were 51 years and 22 kg/m2, respectively. For the overall population, the rate of weight gain increased from 0.47 kg/year preswitch to 0.77 kg/year, with higher increases for females (0.57 kg/year to 0.96 kg/year) than males (0.34 kg/year to 0.62 kg/year). The rate of weight gain for individuals switching from EFV-based regimens significantly increased from 0.57 kg/year preswitch to 1.11 kg/year postswitch but remained stable at 0.35 kg/year preswitch vs 0.32 kg/year postswitch for individuals switching from NVP-based regimens. Conclusions: Switching from NNRTI-based regimens to TLD is associated with a modest increase in the rate of weight gain, with the preswitch NNRTI being the key determinant of the amount of weight gain experienced postswitch.

Effects of the COVID-19 pandemic on late postpartum women living with HIV in Kenya.

Although an estimated 1.4 million women living with HIV (WHIV) are pregnant each year globally, data describing the effects of the COVID-19 pandemic on postpartum women in low- and middle-income countries (LMICs) are limited. To address this gap, we conducted phone surveys among 170 WHIV ≥18 years and 18-24 months postpartum enrolled in HIV care at the Academic Model Providing Access to Healthcare in western Kenya, and assessed the effects of the pandemic across health, social and economic domains. We found that 47% of WHIV experienced income loss and 71% experienced food insecurity during the pandemic. The majority (96%) of women reported having adequate access to antiretroviral treatment and only 3% reported difficulties refilling medications, suggesting that the program's strategies to maintain HIV service delivery during the early phase of the pandemic were effective. However, 21% of WHIV screened positive for depression and 8% for anxiety disorder, indicating the need for interventions to address the mental health needs of this population. Given the scale and duration of the pandemic, HIV programs in LMICs should work with governments and non-governmental organizations to provide targeted support to WHIV at highest risk of food and income insecurity and their associated adverse health outcomes.

Contraception use and HIV outcomes among women initiating dolutegravir-containing antiretroviral therapy in Kenya: a retrospective cohort study.

INTRODUCTION: The rollout of dolutegravir (DTG) in low- and middle-income countries was disrupted by a potential association reported with periconceptional DTG exposure among women living with HIV (WLHIV) and infant neural tube defects. This prompted countries to issue interim guidance limiting DTG use among women of reproductive potential to those on effective contraception. Data to understand the potential impact of such guidance on WLHIV are limited. METHODS: We conducted a retrospective cohort analysis of WLHIV 15-49 years initiating DTG-containing antiretroviral treatment (ART) in Kenya from 2017 to 2020. We determined baseline effective (oral, injectable or lactational amenorrhea) and very effective (implant, intrauterine device or female sterilization) contraception use among women who initiated DTG before (Group 1) or during (Group 2) the interim guideline period. We defined incident contraception use in each group as the number of contraceptive methods initiated ≤180 days post-guideline (Group 1) or post-DTG initiation (Group 2). We determined the proportions of all women who switched from DTG- to non-nucleoside reverse transcriptase inhibitor (NNRTI)- (efavirenz or nevirapine) containing ART ≤12 months post-DTG initiation, compared their viral suppression (<1000 copies/ml) and conducted multivariable logistic regression to determine factors associated with switching from DTG to NNRTI-containing ART. RESULTS: Among 5155 WLHIV in the analysis (median age 43 years), 89% initiated DTG after transitioning from an NNRTI. Baseline effective and very effective contraception use, respectively, by the group were: Group 1 (12% and 13%) and Group 2 (41% and 35%). Incident contraception use in each group was <5%. Overall, 498 (10%) women switched from DTG to an NNRTI. Viral suppression among those remaining on DTG versus switched to NNRTI was 95% and 96%, respectively (p = 0.63). In multivariable analysis, incident effective and very effective contraception use was not associated with switching. CONCLUSIONS: Baseline, but not incident, effective contraception use was higher during the interim guideline period compared to before it, suggesting women already using effective contraception were preferentially selected to initiate DTG after the guideline was released. These findings reveal challenges in the implementation of policy which ties antiretroviral access to contraceptive use. Future guidance should capture nuances of contraception decision-making and support women's agency to make informed decisions.

Predicting neurodevelopmental risk in children born to mothers living with HIV in Kenya: protocol for a prospective cohort study (Tabiri Study).

INTRODUCTION: For the growing number of children with in utero and postpartum exposure to HIV and/or antiretrovirals, it is unclear which exposures or risk factors play a significant role in predicting worse neurodevelopmental outcomes. This protocol describes a prospective longitudinal cohort study of infants born to mothers living with HIV and those born to mothers without HIV. We will determine which risk factors are most predictive of child neurodevelopment at 24 months. We aim to create a risk assessment tool to help predict which children are at risk for worse neurodevelopment outcomes. METHODS AND ANALYSIS: This study leverages an existing Kenyan cohort to prospectively enrol 500 children born to mothers living with HIV and 500 to those without HIV (n=1000 total) and follow them from birth to age 24 months. The following factors will be measured every 6 months: infectious morbidity and biological/sociodemographic/psychosocial risk factors. We will compare these factors between the two groups. We will then measure and compare neurodevelopment within children in both groups at 24 months of age using the Child Behaviour Checklist and the Bayley Scales of Infant and Toddler Development, third edition. Finally, we will use generalised linear mixed modelling to quantify associations with neurodevelopment and create a risk assessment tool for children ≤24 months. ETHICS AND DISSEMINATION: The study is approved by the Moi University's Institutional Research and Ethics Committee (IREC/2021/55; Approval #0003892), Kenya's National Commission for Science, Technology and Innovation (NACOSTI, Reference #700244) and Indiana University's Institutional Review Board (IRB Protocol #110990). This study carries minimal risk to the children and their mothers, and all mothers will provide written consent for participation in the study. Results will be disseminated to maternal child health clinics within Uasin Gishu County, Kenya and via papers submitted to peer-reviewed journals and presentation at international conferences.

Seroprevalence of West Nile Virus among Healthy Blood Donors from Different National Populations Residing in Qatar.

OBJECTIVE: To estimate the age- and nationality-specific West Nile virus (WNV) seroprevalence in select Middle East and North Africa (MENA) populations residing in Qatar. METHODS: Sera were collected from male blood donors attending Hamad Medical Corporation. A total of 1,948 sera were tested for anti-WNV antibodies using Serion ELISA classic IgG and IgM kits. RESULTS: Overall, seroprevalence estimates of WNV-specific IgG and IgM antibodies were 10.4% and 3.3%, respectively. Country-specific WNV-specific IgG seroprevalence was estimated to be 37.0% (34/92) in Sudanese, 33.0% in Egyptians (66/200), 13.0% (26/200) in Indians, 10.6% (11/104) in Iranians, 10.2% (14/137) in Yemenis, 9.2% (18/195) in Pakistanis, 7.0% (14/199) in Jordanians, 5.4% (6/111) in Filipinos, 2.5% (5/200) in Palestinians, 2.5% (5/200) in Syrians, 1.5% (3/200) in Qataris, and 0.9% (1/110) in Lebanese. Seroprevalence of WNV-specific IgM was lowest in Iranians (0/77), Lebanese (0/108), and Filipinos (0/107) at 0.0%, and was highest in Sudanese at 10.0% (8/80). While there seemed to be apparent trends in the prevalence of WNV-IgM and WNV-IgG antibodies, none of these trends were found to be statistically significant. CONCLUSION: The findings support the circulation of WNV in human populations in different countries of the MENA region. Seroprevalence was highest in Sudanese and Egyptians and lowest in Qataris and nationals of the Levant. The findings call for further animal, vector, and human studies, such as studying the actual prevalence of the viral RNA in blood donors to assess the risk of viral transmission through blood donation and for a better characterization of the epidemiology of this infection in this part of the world.

Photoaffinity Labeling and Quantitative Chemical Proteomics Identify LXRß as the Functional Target of Enhancers of Astrocytic apoE.

Utilizing a phenotypic screen, we identified chemical matter that increased astrocytic apoE secretion in vitro. We designed a clickable photoaffinity probe based on a pyrrolidine lead compound and carried out probe-based quantitative chemical proteomics in human astrocytoma CCF-STTG1 cells to identify liver x receptor ß (LXRß) as the target. Binding of the small molecule ligand stabilized LXRß, as shown by cellular thermal shift assay (CETSA). In addition, we identified a probe-modified peptide by mass spectrometry and proposed a model where the photoaffinity probe is bound in the ligand-binding pocket of LXRß. Taken together, our findings demonstrated that the lead chemical matter bound directly to LXRß, and our results highlight the power of chemical proteomic approaches to identify the target of a phenotypic screening hit. Additionally, the LXR photoaffinity probe and lead compound described herein may serve as valuable tools to further evaluate the LXR pathway.

Mortality Among People With HIV Treated for Tuberculosis Based on Positive, Negative, or No Bacteriologic Test Results for Tuberculosis: The IeDEA Consortium.

BACKGROUND: In resource-constrained settings, many people with HIV (PWH) are treated for tuberculosis (TB) without bacteriologic testing. Their mortality compared with those with bacteriologic testing is uncertain. METHODS: We conducted an observational cohort study among PWH ≥15 years of age initiating TB treatment at sites affiliated with 4 International epidemiology Databases to Evaluate AIDS consortium regions from 2012 to 2014: Caribbean, Central and South America, and Central, East, and West Africa. The exposure of interest was the TB bacteriologic test status at TB treatment initiation: positive, negative, or no test result. The hazard of death in the 12 months after TB treatment initiation was estimated using a Cox proportional hazard model. Missing covariate values were multiply imputed. RESULTS: In 2091 PWH, median age 36 years, 53% had CD4 counts ≤200 cells/mm3, and 52% were on antiretroviral therapy (ART) at TB treatment initiation. The adjusted hazard of death was higher in patients with no test compared with those with positive test results (hazard ratio [HR], 1.56; 95% confidence interval [CI], 1.08-2.26). The hazard of death was also higher among those with negative compared with positive tests but was not statistically significant (HR, 1.28; 95% CI, 0.91-1.81). Being on ART, having a higher CD4 count, and tertiary facility level were associated with a lower hazard for death. CONCLUSIONS: There was some evidence that PWH treated for TB with no bacteriologic test results were at higher risk of death than those with positive tests. Research is needed to understand the causes of death in PWH treated for TB without bacteriologic testing.

Diastereoselective synthesis of 2,3,6-trisubstituted piperidines.

We report the diastereoselective and chromatography-free syntheses of four 2-phenyl-6-alkyl-3-aminopiperidines. Ring construction was accomplished through a nitro-Mannich reaction linking a nitroketone and phenylmethanimine, followed by a ring-closure condensation. Relative stereocontrol was achieved between C-2 and C-3 by kinetic protonation of a nitronate or by equilibration of the nitro group under thermodynamic control. Stereocontrol at C-6 was accomplished by utilizing a variety of imine reduction methods. The C-2/C-6-cis stereochemistry was established via triacetoxyborohydride iminium ion reduction, whereas the trans relationship was set either by triethylsilane/TFA acyliminium ion reduction or by Lewis acid catalyzed imine reduction with lithium aluminum hydride.

Stated-preference research in HIV: A scoping review.

Discrete choice experiments (DCE), conjoint analysis (CA), and best-worst scaling (BWS) are quantitative techniques for estimating consumer preferences for products or services. These methods are increasingly used in healthcare research, but their applications within the field of HIV research have not yet been described. The objective of this scoping review was to systematically map the extent and nature of published DCE, CA, and BWS studies in the field of HIV and identify priority areas where these methods can be used in the future. Online databases were searched to identify published HIV-related DCE, CA and BWS studies in any country and year as the primary outcome. After screening 1,496 citations, 57 studies were identified that were conducted in 26 countries from 2000-2017. The frequency of published studies increased over time and covered HIV themes relating to prevention (n = 25), counselling and testing (n = 10), service delivery (n = 10), and antiretroviral therapy (n = 12). Most studies were DCEs (63%) followed by CA (37%) and BWS (4%). The median [IQR] sample size was 288 [138-496] participants, and 74% of studies used primary qualitative data to develop attributes. Only 30% of studies were conducted in sub-Saharan Africa where the burden of HIV is highest. Moreover, few studies surveyed key populations including men who have sex with men, transgender people, pregnant and postpartum women, adolescents, and people who inject drugs. These populations represent priorities for future stated-preference research. This scoping review can help researchers, policy makers, program implementers, and health economists to better understand the various applications of stated-preference research methods in the field of HIV.

Viral suppression among children and their caregivers living with HIV in western Kenya.

INTRODUCTION: Despite the central role of caregivers in managing HIV treatment for children living with HIV, viral suppression within caregiver-child dyads in which both members are living with HIV is not well described. METHODS: We conducted a retrospective analysis of children living with HIV <15 years of age and their caregivers living with HIV attending HIV clinics affiliated with the Academic Model Providing Access to Healthcare (AMPATH) in Kenya between 2015 and 2017. To be included in the analysis, children and caregivers must have had ≥1 viral load (VL) during the study period while receiving antiretroviral therapy (ART) for ≥6 months, and the date of the caregiver's VL must have occurred ±90 days from the date of the child's VL. The characteristics of children, caregivers and dyads were descriptively summarized. Multivariable logistic regression was used to estimate the odds of viral non-suppression (≥ 1000 copies/mL) in children, adjusting for caregiver and child characteristics. RESULTS: Of 7667 children who received care at AMPATH during the study period, 1698 were linked to a caregiver living with HIV and included as caregiver-child dyads. For caregivers, 94% were mothers, median age at ART initiation 32.8 years, median CD4 count at ART initiation 164 cells/mm3 and 23% were not virally suppressed. For children, 52% were female, median age at ART initiation 4.2 years, median CD4 values at ART initiation were 15% (age < 5 years) and 396 cells/mm3 (age ≥ 5 years), and 38% were not virally suppressed. In the multivariable model, children were found more likely to not be virally suppressed if their caregivers were not suppressed compared to children with suppressed caregivers (aOR = 2.40, 95% CI: 1.86 to 3.10). Other characteristics associated with child viral non-suppression included caregiver ART regimen change prior to the VL, caregiver receipt of a non-NNRTI-based regimen at the time of the VL, younger child age at ART initiation and child tuberculosis treatment at the time of the VL. CONCLUSIONS: Children were at higher risk of viral non-suppression if their caregivers were not virally suppressed compared to children with suppressed caregivers. A child's viral suppression status should be closely monitored if his or her caregiver is not suppressed.

Dengue and chikungunya seroprevalence among Qatari nationals and immigrants residing in Qatar.

The objective of this study is to characterize the seroprevalence of anti-dengue (DENV) and anti-chikungunya (CHIKV) antibodies among blood donors residing in Qatar who are Middle East and North Africa (MENA) nationals and non-nationals. Sera were collected from adult blood donors in Qatar from 2013 to 2016 and tested for anti-DENV and anti-CHIKV IgG using commercial microplate enzyme-linked immunosorbent assays. Age-specific seroprevalence was summarized by region/nationality: Asia (India, Philippines), Middle East (Iran, Jordan, Lebanon, Pakistan, Palestine, Syria, Yemen), North Africa (Egypt, Sudan), Qatar. The adjusted odds of anti-DENV and anti-CHIKV IgG seropositivity was estimated by logistic regression. Among 1,992 serum samples tested, Asian nationals had higher adjusted odds of being seropositive for anti-DENV antibodies compared to nationals of the Middle East (aOR 0.05, 95% CI 0.04-0.07), North Africa (aOR 0.14, 95% CI 0.10-0.20), and Qatar (aOR 0.01, 95% CI 0.01-0.03). Asian nationals also had higher adjusted odds of being seropositive for anti-CHIKV antibodies compared to those from the Middle East (aOR 0.14, 95% CI 0.07-0.27), North Africa (aOR 0.50, 95% CI 0.26-0.96), and Qatar (aOR 0.38, 95% CI 0.15-0.96). The adjusted odds of being anti-DENV seropositive was higher among anti-CHIKV seropositive adults, and vice versa (aOR 1.94, 95% CI 1.09-3.44), suggesting co-circulation of these viruses. DENV and CHIKV exposure is lower in Qatar and MENA nationals compared to Asian nationals suggesting a lower burden of DENV and CHIKV disease in the MENA. Antibodies to both viruses were detected in nationals from most MENA countries, supporting the need to better understand the regional epidemiology of these viruses.