A Case Series of Ocular Syphilis Cases at Military Treatment Facility From 2020 to 2021.

Syphilis is a sexually transmitted infection, caused by the spirochete Treponema pallidum, that can lead to multi-organ involvement. In 2020, over 138,000 cases were reported in the United States equating to a case report of 40.8 per 100,000 people. Ocular syphilis is a rare manifestation and is defined as the clinical presentation of ocular disease in a person with laboratory-confirmed syphilis infection of any stage, with estimated incidence of 0.6-2% of all cases. Syphilis is known as "The Great Imitator," and can present as nearly any form of ocular disease, though the most common manifestations are posterior uveitis and panuveitis. The highly variable clinical presentation of ocular syphilis often leads to delayed diagnosis allowing the potential for poor, often preventable outcomes. This highlights the need for providers to have a high level of clinical suspicion and awareness of ocular manifestations of syphilis, especially in high risk populations. We present a case series of five patients diagnosed with ocular syphilis at a military treatment facility. Each patient had different presenting symptoms as well as different ocular manifestations.

Patients with HIV-associated cancers have evidence of increased T cell dysfunction and exhaustion prior to cancer diagnosis.

BACKGROUND: People living with HIV (PLWH) have increased risk of developing cancers after controlling traditional risk factors and viral suppression. This study explores whether T cells can serve as a marker of risk for cancer among HIV-infected virally suppressed patients. METHODS: A nested case control study design was pursued with 17 cancer cases and 73 controls (PLWH without cancer)ouidentified among the US Military HIV Natural History Study cohort, and were matched for CD4 + count, duration of HIV infection, and viral suppression. Cells were obtained from PLWH on an average of 12 months prior to clinical cancer diagnosis. Expression of inhibitory receptors (PD-1, CD160, CD244, Lag-3, and TIGIT), and transcription factors (T-bet, Eomesodermin, TCF-1, and (TOX) was measured on CD8 +T cells from that early time point. RESULTS: We found that cases have increased expression of PD-1 +CD160+CD244+ ('triple positive') on total and effector CD8 + compared with controls (p=0.02). Furthermore, CD8 +T cells that were both PD-1 +CD160+CD244+ and T-betdimEomeshi were significantly elevated in cases at time point before cancer detection, compared with controls without cancer (p=0.008). This was driven by the finding that transcriptional factor profile of cells was altered in cancers compared with controls. Triple-positive cells were noted to retain the ability for cytotoxicity and cytokine secretion mediated by expression of CD160 and PD-1, respectively. However, triple-positive cells demonstrated high expression of TOX-1, a transcription factor associated with T cell exhaustion. CONCLUSION: In conclusion, we have found a subset of dysfunctional CD8 +T cells, PD-1 +CD160+CD244+T-betdimEomeshi, that is elevated 12 months before cancer diagnosis, suggesting that peripheral T cell alterations may serve as a biomarker of increased cancer risk among PLWH.

Statin usage and cardiovascular risk among people living with HIV in the U.S. Military HIV Natural History Study.

OBJECTIVES: Using the American College of Cardiology/American Heart Association 2013 atherosclerotic cardiovascular disease (ASCVD) management guidelines, we conducted a retrospective cross-sectional analysis of people living with HIV in the US Military HIV Natural History Study to determine whether individuals were receiving statins when indicated. METHODS: Prescription data was taken from Military Health System data. Statin eligibility was defined by ASCVD guidelines. We used the 10-year ASCVD pooled cohorts' equation to evaluate risk for each participant. RESULTS: Across all categories, 31.9% (n = 390) of individuals met criteria for statin use, and when adding these subjects to the number of those already receiving statins (n = 96), 62.1% of all eligible subjects (n = 302/486) were actually receiving statin therapy. In multivariable analysis, individuals of African American race [odds ratio (OR) = 0.48, 95% confidence interval (CI): 0.31-0.73] or Hispanic ethnicity (OR = 0.42, 95% CI: 0.19-0.94) were less likely to receive statin prescriptions than white individuals. Individuals with a higher CD4 count (OR = 1.12, 95% CI: 1.05-1.20 per 100 cells/µL]) were significantly more likely to receive a statin prescription. CONCLUSIONS: These data highlight discrepancies between ASCVD guidelines and primary care management of people living with HIV (PLWH) in the military health system, along with important racial differences. Targeted interventions are critical to identify and treat appropriate candidates for statin therapy among PLWH in the military and other settings.

Association between depression and HIV treatment outcomes in a US military population with HIV infection.

BACKGROUND: Depression is common among HIV-infected individuals and may contribute to suboptimal adherence to antiretroviral therapy (ART) and subsequent inability to attain viral load (VL) suppression. We evaluated associations between depression, self-reported adherence, and longitudinal HIV treatment outcomes in US Military HIV Natural History Study (NHS) participants with and without depression. METHODS: Male NHS participants with available ICD-9 data for mental health diagnoses, Center for Epidemiological Studies Depression (CES-D) measures, and self-reported adherence (SRA) were included. ART use was defined as ART initiation between 2006 and 2010, with follow-up through 2015. SRA was defined as taking 95% of ART doses and continuous ART was defined as longitudinal ART use with gaps < 30 days. Continuous VL suppression was defined as maintaining VLs < 200 c/mL on ART. To analyse the association between depression and HIV treatment outcomes, latent class analysis was used to create classes of depression trajectories: low depression (LD), recent onset depression (ROD) and high Depression (HD). RESULTS: Participants had a mean age of 32 (± 8.3) years at HIV diagnosis, and similar proportions were Caucasian (44.3%) or African American (40.8%). Overall, older participants at HIV diagnosis had greater odds of having 95% self-reported adherence (OR 1.06, 95% CI 1.02-1.12), and African Americans had lower odds (OR 0.41, 95% CI 0.22-0.76) compared to Caucasians (OR 1.49, 95% CI 0.52-4.28). However, there was no difference in SRA by depression trajectory. Participants with HD had an increased odds of taking ART continuously (OR 1.75, 95% CI 0.99-3.09), and those with ROD had significantly higher odds of virologic failure (OR 0.58, 95% CI 0.38-0.91). CONCLUSIONS: Although there was no observed association between depression and SRA, participants with ROD had lower odds of attaining the HIV treatment goal of VL suppression. Continued efforts to identify and aggressively manage mental health disorders is important to success along the HIV care continuum.

Risk Factors Associated With Chronic Liver Enzyme Elevation in Persons With HIV Without Hepatitis B or C Coinfection in the Combination Antiretroviral Therapy Era.

BACKGROUND: As morbidity due to viral coinfections declines among HIV-infected persons, changes in liver-related morbidity are anticipated. We examined data from the US Military HIV Natural History Study (NHS), a cohort of military beneficiaries, to evaluate incidence and risk factors associated with chronic liver enzyme elevation (cLEE) in HIV-monoinfected patients in the combination antiretroviral therapy (cART) era. METHODS: Participants who were hepatitis B virus and hepatitis C virus seronegative with follow-up after 1996 were included. We defined chronic liver enzyme elevation (cLEE) as alanine aminotransferase elevations ≥1.25 times the upper limit of normal on at least 2 visits, for a duration of ≥6 months within 2 years. We used multivariate Cox proportional hazards models to examine risk factors for cLEE. RESULTS: Of 2779 participants, 309 (11%) met criteria for cLEE for an incidence of 1.28/100 PYFU (1.28-1.29/100 PYFU). In an adjusted model, cLEE was associated with Hispanic/other ethnicity (reference Caucasian: hazard ratio [HR], 1.744; 95% CI, 1.270-2.395), non-nucleoside reverse transcriptase inhibitor-based cART (reference boosted protease inhibitors: HR, 2.232; 95% CI, 1.378-3.616), being cART naïve (HR, 6.046; 95% CI, 3.686-9.915), or having cART interruptions (HR, 8.671; 95% CI, 4.651-16.164). African American race (HR, 0.669; 95% CI, 0.510-0.877) and integrase strand transfer inhibitor (INSTI)-based cART (HR, 0.222; 95% CI, 0.104-0.474) were protective. CONCLUSIONS: Our findings demonstrate that initiation and continued use of cART are protective against cLEE and support the hypothesis that HIV infection directly impacts the liver. INSTI-based regimens were protective and could be considered in persons with cLEE.

SARS-CoV-2 Infections and Serologic Responses Among Military Personnel Deployed on the USNS COMFORT to New York City During the COVID-19 Pandemic.

BACKGROUND: Coronavirus disease 2019 (COVID-19) presents a unique challenge to United States Navy hospital ships. The aim of this study was to determine the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among US Navy personnel deployed on the USNS COMFORT to augment the inpatient health care capacity in New York City. METHODS: This was a cross-sectional study conducted on USNS COMFORT crewmembers returning to Norfolk, Virginia, following deployment. Participants completed an electronic questionnaire and provided a serum sample at Day 14 post-deployment. Polymerase chain reaction (PCR) results from testing of symptomatic crewmembers during deployment and Day 0 and Day 14 post-deployment screening swabs conducted on all crewmembers, per military order, were abstracted. SARS-CoV-2 infection was defined as a positive SARS-CoV-2 spike glycoprotein immunoglobulin G antibody or PCR result. RESULTS: Of the ship's total complement of 1200 crewmembers, 450 were enrolled: 432 (96.0%) completed the questionnaire and provided a serum sample. The median age of participants (interquartile range) was 30 (24-39) years, 50.8% were female, 58.6% were White, and 14.0% were Black; 80.1% had a clinical role during deployment. The cumulative prevalence of SARS-CoV-2 infection was 3.01% (13/432; 95% CI, 1.61%-5.09%). Twelve of 13 infections occurred in health care providers, and 8 of 13 were asymptomatic. The antibody profile of infected crewmembers varied by suspected timing of infection. CONCLUSIONS: We observed a low prevalence of SARS-CoV-2 infection among USNS COMFORT crewmembers despite the inherent risk of a shipboard deployment to an area with high rates of community transmission. Our findings suggest that early infection control measures mitigated the spread of SARS-CoV-2 among crewmembers.

Antiretroviral Therapy Anchor-based Trends in Body Mass Index Following Treatment Initiation Among Military Personnel with HIV.

INTRODUCTION: Weight gain and obesity in people living with HIV have been associated with increased risk for non-AIDS-related comorbidities, and integrase strand transfer inhibitor (INSTI)-based regimens may lead to comparatively more weight gain than other regimens. We evaluated body mass index (BMI) following antiretroviral therapy (ART) initiation among participants in the U.S. Military HIV Natural History Study (NHS). MATERIALS AND METHODS: NHS participants with available baseline weight and height data initiating ART from 2006 to 2017 were considered for analysis. Antiretroviral therapy was categorized by anchor class to include INSTIs, non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs). Linear growth-curve modeling was used to predict BMI changes from ART initiation through 2 years of follow-up in participants stratified by baseline BMI (<25 vs ≥25 kg/m2) at ART start and anchor drug class. These models were adjusted for demographic- and HIV-related characteristics. RESULTS: Of 961 NHS participants started on initial ART between 2006 and 2017, 491 men who had available baseline BMI data and were virally suppressed (<200 c/mL) at 1 and 2 years of follow-up were included. Overall, the predicted BMI increased at each time point over 2 years regardless of baseline BMI. There was a trend toward less weight gain for non-INSTI regimens regardless of demographic- or HIV-related factors (-0.65 kg/m2/yr, P = .070). In participants with BMI <25, all regimens were associated with BMI gains except in those with high viral load (≥100,000 copies/mL) started on PI regimens (-1.91 kg/m2/yr, P = .000; n = 13). For those participants with BMI ≥25, only INSTI- and PI-based regimens were significantly associated with increased BMI (INSTI 0.54 kg/m2/y, P = .000; PI 0.39 kg/m2/yr, P = .006). Non-nucleoside reverse transcriptase inhibitors were not associated with weight gain regardless of race- or HIV-related characteristics. African Americans with BMI ≥25 were more likely to gain weight as compared to Whites (0.99 kg/m2/yr, P = .016). Specific anchor drug-based predictions revealed that only INSTI use among African Americans was significantly associated with BMI gains (1.85 kg/m2/yr, P = .007); NNRTI- and PI-related weight change was not significant as compared to Whites. CONCLUSIONS: In our cohort of young military members with HIV infection, those with BMI <25 experienced BMI gains across all ART classes. Among those with BMI ≥25, African Americans on INSTI regimens had the greatest BMI gains. Further studies are needed to determine whether NNRTI regimens should be considered in certain individuals at risk for INSTI-associated weight gain.

Bacteroides Fragilis Vertebral Osteomyelitis and Discitis: "Back" to Susceptibility Testing.

Genetic testing of anaerobic isolates can be important for proper antimicrobial stewardship to identify the appropriate narrow-spectrum treatment for a polymicrobial infection.

The US Military HIV Natural History Study: Informing Military HIV Care and Policy for Over 30 Years.

INTRODUCTION: In October 1985, 4 years after the initial descriptions of the acquired immunodeficiency syndrome (AIDS), the U.S. Department of Defense (DoD) began routine screening for human immunodeficiency virus (HIV) infection to prevent infected recruits from exposure to live virus vaccines, implemented routine active-duty force screening to ensure timely care and help protect the walking blood bank, and initiated the U.S. Military HIV Natural History Study (NHS) to develop epidemiologic, clinical, and basic science evidence to inform military HIV policy and establish a repository of data and specimens for future research. Here, we have reviewed accomplishments of the NHS over the past 30 years and sought to describe relevant trends among NHS subjects over this time, with emphasis on combination antiretroviral therapy (cART) use and non-AIDS comorbidities. METHODS: Subjects who were prospectively enrolled in the NHS from 1986 through 2015 were included in this analysis. Time periods were classified by decade of study conduct, 1986-1995, 1996-2005, and 2006-2015, which also correlate approximately with pre-, early-, and late-combination ART (cART) eras. Analyses included descriptive statistics and comparisons among decades. We also evaluated mean community log10 HIV viral load (CVL) and CD4 counts for each year. RESULTS: A total of 5,758 subjects were enrolled between 1986 and 2015, of whom 92% were male with a median age of 28 years, and 45% were African-American, 42% Caucasian, and 13% Hispanic/other. The proportion of African-Americans remained stable over the decades (45%, 47%, and 42%, respectively), while the proportion of Hispanic/other increased (10%, 13%, and 24%, respectively). The CD4 count at HIV diagnosis has remained high (median 496 cells/uL), while the occurrence of AIDS-defining conditions (excluding low CD4 count) has decreased by decade (36.7%, 5.4%, and 2.9%, respectively). Following the introduction of effective cART in 1996, CVL declined through 2000 as use increased and then plateaued until guidelines changed. After 2004, cART use again increased and CVL declined further until 2012-15 when the vast majority of subjects achieved viral suppression. Non-AIDS comorbidities have remained common, with approximately half of subjects experiencing one or more new diagnoses overall and nearly half of subjects diagnosed between 2006 and 2015, in spite of their relatively young age, shorter median follow-up, and wide use of cART. CONCLUSIONS: The US Military HIV NHS has been critical to understanding the impact of HIV infection among active-duty service members and military beneficiaries, as well as producing insights that are broadly relevant. In addition, the rich repository of NHS data and specimens serves as a resource to investigators in the DoD, NIH, and academic community, markedly increasing scientific yield and identifying novel associations. Looking forward, the NHS remains relevant to understanding host factor correlates of virologic and immunologic control, biologic pathways of HIV pathogenesis, causes and consequences of residual inflammation in spite of effective cART, identifying predictors of and potential approaches to mitigation of excess non-AIDS comorbidities, and helping to understand the latent reservoir.

Correction: Rodent-borne infections in rural Ghanaian farming communities.

[This corrects the article DOI: 10.1371/journal.pone.0215224.].

Rodent-borne infections in rural Ghanaian farming communities.

Rodents serve as reservoirs and/or vectors for several human infections of high morbidity and mortality in the tropics. Population growth and demographic shifts over the years have increased contact with these mammals, thereby increasing opportunities for disease transmission. In Africa, the burden of rodent-borne diseases is not well described. To investigate human seroprevalence of selected rodent-borne pathogens, sera from 657 healthy adults in ten rural communities in Ghana were analyzed. An in-house enzyme-linked immunosorbent assay (ELISA), for immunoglobulin G (IgG) antibodies to Lassa virus was positive in 34 (5%) of the human samples. Using commercial kits, antibodies to hantavirus serotypes, Puumala and Dobrava, and Leptospira bacteria were detected in 11%, 12% and 21% of the human samples, respectively. Forty percent of residents in rural farming communities in Ghana have measurable antibodies to at least one of the rodent-borne pathogens tested, including antibodies to viral hemorrhagic fever viruses. The high seroprevalence found in rural Ghana to rodent-borne pathogens associated with both sporadic cases and larger disease outbreaks will help define disease threats and inform public health policy to reduce disease burden in underserved populations and deter larger outbreaks.

Persistent Low-level Viremia While on Antiretroviral Therapy Is an Independent Risk Factor for Virologic Failure.

BACKGROUND: Whether persistent low-level viremia (pLLV) predicts virologic failure (VF) is unclear. We used data from the US Military HIV Natural History Study (NHS), to examine the association of pLLV and VF. METHODS: NHS subjects who initiated combination antiretroviral therapy (ART) after 1996 were included if they had 2 or more VLs measured with a lower limit of detection of ≤50 copies/mL. VF was defined as a confirmed VL ≥200 copies/mL or any VL >1000 copies/mL. Participants were categorized into mutually exclusive virologic categories: intermittent LLV (iLLV) (VL of 50-199 copies/mL on <25% of measurements), pLLV (VL of 50-199 copies/mL on ≥25% of measurements), high-level viremia (hLV) (VL of 200-1000 copies/mL), and continuous suppression (all VL <50 copies/mL). Cox proportional hazards models were used to evaluate the association between VF and LLV; hazard ratios and 95% confidence interval (CI) are presented. RESULTS: Two thousand six subjects (median age 29.2 years, 93% male, 41% black) were included; 383 subjects (19%) experienced VF. After adjusting for demographics, VL, CD4 counts, ART regimen, prior use of mono or dual antiretrovirals, and time to ART start, pLLV (3.46 [2.42-4.93]), and hLV (2.29 [1.78-2.96]) were associated with VF. Other factors associated with VF include black ethnicity (1.33 [1.06-1.68]) and antiretroviral use prior to ART (1.79 [1.34-2.38]). Older age at ART initiation (0.71 [0.61-0.82]) and non-nucleoside reverse transcriptase inhibitor (0.68 [0.51-0.90]) or integrase strand transfer inhibitor use (0.26 [0.13-0.53]) were protective. CONCLUSION: Our data add to the body of evidence that suggests persistent LLV is associated with deleterious virologic consequences.

Age, Race, and At-Risk Drinking in an HIV-infected U.S. Military Cohort.

INTRODUCTION: There is a high prevalence of at-risk drinking in the U.S. military. Among HIV-infected individuals, alcohol abuse confers additional risk for adverse health outcomes. In the military, however, the characteristics of HIV-infected individuals who engage in high-risk drinking are not well defined. The purpose of this study was to assess risk factors associated with at-risk drinking in an HIV-positive longitudinal cohort of DoD beneficiaries. MATERIALS AND METHODS: Annual prevalence of at-risk drinking was calculated for members of the U.S. Military HIV Natural History Study who initiated highly active antiretroviral therapy (HAART) during or after January 2006 through May 2014; each participant completed at least one self-reported alcohol survey within a year of HAART initiation. Univariate and multivariable logistic regression was used to analyze factors associated with at-risk drinking. RESULTS: Sixty-six percent of subjects (495/752) reported at-risk drinking on at least one survey after HAART initiation. At-risk drinkers were more likely to be Active Duty compared to Retired (OR 0.65 95% CI [0.46, 0.92]). In multivariate models, Caucasian race (OR 3.30 95% CI [2.31, 4.71]); Hispanic/other race (OR 2.17 95% CI [1.51, 3.14]) and younger age (OR 0.61 per 10 years older, [95%CI 0.49, 0.75]) were significantly associated with at-risk drinking. Single relationship status (OR 1.51 95% CI [1.08, 2.13]) was also associated with at-risk drinking. CONCLUSIONS: Consistent with general alcohol consumption patterns in the military, we found a high prevalence of at-risk drinking among individuals with HIV infection, which was associated most closely with young, non-African Americans. Targeting interventions toward this group will be important to reduce at-risk drinking and its potential for HIV-related complications.

Herpes Zoster Rates Continue to Decline in People Living With Human Immunodeficiency Virus but Remain Higher Than Rates Reported in the General US Population.

In the antiretroviral therapy era, herpes zoster incidence continued to decline in people living with HIV (PLWH). However, at 0.9 cases/100 person-years, rates in PLWH are substantially higher than the general US population; emphasizing the needs for studies of the subunit vaccine in PLWH.

Honey Bee Swarms Aboard the USNS Comfort: Recommendations for Sting Prevention, Swarm Removal, and Medical Readiness on Military Ships.

The article provides observations of multiple honey bee (Apis mellifera) swarms aboard the USNS Comfort (TAH-20) during the Continuing Promise 2015 mission. A brief overview of swarming biology is given along with control/removal recommendations to reduce sting exposures. The observations suggest that preventive medicine personnel should provide adequate risk communications about the potential occurrence of bee swarms aboard military ships, and medical department personnel should be prepared for the possibility of treating of multiple sting exposures, especially in the Southern Command Area of Operations where the Africanized genotype of A mellifera is common.

Safety and Immunogenicity of EBA-175 RII-NG Malaria Vaccine Administered Intramuscularly in Semi-Immune Adults: A Phase 1, Double-Blinded Placebo Controlled Dosage Escalation Study.

The erythrocyte binding antigen region II (EBA-175 RII) is a Plasmodium falciparum ligand that mediates erythrocyte invasion and is considered an important malaria vaccine candidate. A phase Ia trial in malaria naïve adults living in the United States found the recombinant non-glycosylated vaccine antigen, EBA-175 RII-NG adjuvanted with aluminium phosphate to be safe, immunogenic and capable of inducing biologically active antibodies that can inhibit parasite growth in vitro. The aim of the current study was to assess the safety and immunogenicity of this vaccine in malaria exposed semi-immune healthy adults living in a malaria endemic country, Ghana. In this double-blinded, placebo controlled, dose escalation phase I trial, eighteen subjects per group received ascending dose concentrations (5 µg, 20 µg or 80 µg) of the vaccine intramuscularly at 0, 1 and 6 months, while 6 subjects received placebo (normal saline). The primary end point was the number of subjects experiencing Grade 3 systemic or local adverse events within 14 days post-vaccination. Serious adverse events were assessed throughout the study period. Blood samples for immunological analyses were collected at days 0, 14, 28, 42, 180 and 194. A total of 52 subjects received three doses of the vaccine in the respective groups. No serious adverse events were reported. The majority of all adverse events reported were mild to moderate in severity, with local pain and tenderness being the most common. All adverse events, irrespective of severity, resolved without any sequelae. Subjects who received any of the EBA-175 RII-NG doses had high immunoglobulin G levels which moderately inhibited P. falciparum growth in vitro, compared to those in the placebo group. In conclusion, the EBA-175 RII-NG vaccine was safe, well tolerated and immunogenic in malaria semi-immune Ghanaian adults. Its further development is recommended. TRIAL REGISTRATION: ClinicalTrials.gov. Identifier: NCT01026246.

A comparison of compliance rates with anti-vectorial protective measures during travel to regions with dengue or chikungunya activity, and regions endemic for Plasmodium falciparum malaria.

BACKGROUND: There is limited information on compliance rates with anti-vectorial protective measures (AVPMs) during travel to countries with risk of dengue and chikungunya. We evaluated differences in mosquito exposures, and factors associated with AVPM compliance in travellers going to countries where the principal mosquito-borne infectious disease threat is falciparum malaria and those where risk of dengue or chikungunya predominates. METHODS: Department of Defence beneficiaries with planned travel to regions where the predominant mosquito-borne infection is falciparum malaria, and those with predominantly dengue or chikungunya risk, were included. Regions were divided into three groups: 'high-risk falciparum malaria', 'low-risk falciparum malaria' and 'chikungunya/dengue risk'. Demographics, trip characteristics, arthropod exposure and AVPM compliance were captured using pre- and post-travel surveys. Skin repellent compliance was defined as self-reported use, categorized as 'often/every day'. A logistic regression model was used to estimate factors associated with AVPM compliance. RESULTS: 183 (9%), 185 (9%) and 149 (7%) travelled to high and low falciparum malaria risk regions, and chikungunya/dengue risk regions, respectively. Overall, 53% (95% CI: 48-57%) and 16% (95% CI: 12-19%) were compliant with repellent use on skin and clothing, respectively. Daytime bites were reported more frequently in chikungunya/dengue risk regions than high malaria risk regions (37% vs. 10%), while night time bites were frequently in high malaria risk regions (53% vs 20%; P < 0.001). Compliance with skin repellents was associated with female gender [RR: 1.54 (95% CI: 1.05-2.28)], observing mosquitoes during travel [RR: 2.77 (95% CI: 1.76-4.36)] and travel during the rainy season [RR: 2.45 (95% CI: 1.66-3.71)]). CONCLUSIONS: Poor AVPM compliance was observed in the overall cohort. Compliance with skin repellent use was associated with female gender, observing mosquitoes and travelling during the rainy season, and was not associated with the risk of malaria or chikungunya/dengue at the travel destination.