Comparative analysis of peripheral whole blood transcriptome from asymptomatic carriers reveals upregulation of subsets of surface proteins implicated in Plasmodium falciparum phenotypic plasticity

The molecular mechanism underlying Plasmodium falciparum's persistence in the asymptomatic phase of infection remains largely unknown. However, large-scale shifts in the parasites' gene expression during asymptomatic infections may enhance phenotypic plasticity, maximizing their fitness and leading to the persistence of the asymptomatic infections. To uncover these mechanisms, we aimed to identify parasite genetic factors implicated in asymptomatic infections through whole transcriptome analysis. We analyzed publicly available transcriptome datasets containing asymptomatic malaria (ASM), uncomplicated malaria (SM), and malaria-naïve (NSM) samples from 35 subjects for differentially expressed genes (DEGs) and long noncoding RNAs. Our analysis identified 755 and 1773 DEGs in ASM vs SM and NSM, respectively. These DEGs revealed sets of genes coding for proteins of unknown functions (PUFs) upregulated in ASM vs SM and ASM, suggesting their role in underlying fundamental molecular mechanisms during asymptomatic infections. Upregulated genes in ASM vs SM revealed a subset of 24 clonal variant genes (CVGs) involved in host-parasite and symbiotic interactions and modulation of the symbiont of host erythrocyte aggregation pathways. Moreover, we identified 237 differentially expressed noncoding RNAs in ASM vs SM, of which 11 were found to interact with CVGs, suggesting their possible role in regulating the expression of CVGs. Our results suggest that P. falciparum utilizes phenotypic plasticity as an adaptive mechanism during asymptomatic infections by upregulating clonal variant genes, with long noncoding RNAs possibly playing a crucial role in their regulation. Thus, our study provides insights into the parasites' genetic factors that confer a fitness advantage during asymptomatic infections.

Therapeutic response to artemisinin combination therapies among individuals with Plasmodium falciparum single infection versus mixed Plasmodium species infections: A retrospective post-hoc analysis in Kisumu County, western Kenya

OBJECTIVE

This study examined the treatment response of mixed versus single species Plasmodium falciparum infections to artemisinin-based combination therapies (ACTs).

METHODS

1211 blood samples collected on days 0, 7, 14, 21, 28, 35, and 42 from 173 individuals enrolled under two randomized ACT efficacy studies were diagnosed for malaria using 18s rRNA-based real-time PCR. All recurrent parasitaemia were characterized for Plasmodium species composition and times to reinfection during 42-day follow up compared across ACTs.

FINDINGS

Day 0 samples had 71.1% (116/163) single P. falciparum infections and 28.2% (46/163) co-infections. 54.0% (88/163) of individuals tested Plasmodium positive at least once between days 7 - 42. 19.3% (17/88) of individuals with recurrent infections were infected with a different Plasmodium species than observed at day 0, with 76.5% (13/17) of these "hidden" infections appearing after clearing P. falciparum present at day 0. Artesunate-mefloquine (16.4) and dihydroartemisinin-piperaquine (17.6) had increased clearance rates over artemether-lumefantrine (21.0). Dihydroartemisinin-piperaquine exhibited the longest duration of reinfection prophylaxis. Cure rates were comparable across each species composition.

INTERPRETATION

No differences in clearance rates were found depending on whether the infection contained other species other than P. falciparum. Significantly longer durations of protection were observed for individuals treated with dihydroartemisinin-piperaquine.

Associations of gender identity with sexual behaviours, social stigma and sexually transmitted infections among adults who have sex with men in Abuja and Lagos, Nigeria

Introduction

Sexual and gender minority populations are disproportionately affected by the global syndemic of HIV and other sexually transmitted infections (STIs). We hypothesized that transgender women (TGW) and non‐binary individuals in Nigeria have more STIs than cis‐gender men who have sex with men (cis‐MSM), and that experiences of stigma and sexual practices differ between these three groups.

Methods

From 2013 to 2020, TRUST/RV368 enrolled adults assigned male sex at birth who reported anal sex with men in Abuja and Lagos, Nigeria. Participants were tested for STIs and completed questionnaires about sexual behaviours and social stigma every 3 months. Participants were categorized as cis‐MSM, TGW or non‐binary/other based on self‐reported gender identity. Gender group comparisons were made of HIV, gonorrhoea and chlamydia prevalence and incidence; stigma indicators; and condom use during anal sex.

Results

Among 2795 participants, there were 2260 (80.8%) cis‐MSM, 284 (10.2%) TGW and 251 (9.0%) non‐binary/other individuals with median age of 23 years (interquartile range 20–27). HIV prevalence among cis‐MSM, TGW and non‐binary/other participants was 40.8%, 51.5% and 47.6%, respectively (p = 0.002). HIV incidence was 8.7 cases per 100 person‐years (PY) (95% confidence interval [CI] 6.9–10.8), 13.1 cases/100 PY (95% CI 6.5–23.4) and 17.6 cases/100 PY (95% CI 9.8–29.0, p = 0.025), respectively. Anorectal gonorrhoea incidence was lower in cis‐MSM than TGW (22.2 [95% CI 19.6–25.0] vs. 35.9 [95% CI 27.3–46.3]). TGW were more likely than cis‐MSM to report being affected by stigma, including assault (47.2% vs. 32.3%), fear of walking around (32.4% vs. 19.2%) and healthcare avoidance (25.0% vs. 19.1%; all p < 0.05). TGW were more likely to report always using condoms than non‐binary/other individuals (35.3% vs. 26.2%, p = 0.041) during receptive anal sex.

Conclusions

Sexual and gender minorities in Nigeria have heterogeneous sexual behaviours and experiences of social stigma that may influence the vulnerability to HIV and other STIs. There is a need for tailored interventions that acknowledge and are informed by gender. Further research is needed, particularly among understudied non‐binary individuals, to better understand disparities and inform tailored interventions to improve outcomes among these communities.

Sexually Transmitted Infections in the U.S. Military: A Sexual Health Paradigm to Address Risk Behaviors, Unintended Pregnancy, Alcohol Use, and Sexual Trauma

To address the ongoing epidemic of sexually transmitted infections (STIs) in the United States, the National Academies of Sciences, Engineering, and Medicine (National Academies) conducted a consensus study on STI control and prevention in the United States to provide recommendations to the Centers for Disease Control and Prevention and the National Association of County and City Health Officials. The culminating report identified military personnel as one of the priority groups that require special consideration given the high prevalence of STIs and their associated behaviors (e.g., concurrent sexual partners and infrequent condom use) that occur during active duty service. Universal health care access, the relative ease and frequency of STI screening, and the educational opportunities within the military are all assets in STI control and prevention. The report offers a comprehensive framework on multiple and interrelated influences on STI risk, prevention, health care access, delivery, and treatment. It also provides an overview of the multilevel risk and protective factors associated with STIs that could be applied using a sexual health paradigm. The military context must integrate the multilevel domains of influences to guide the effort to fill current gaps and research needs. The Department of Defense, with its large clinical and preventive medicine workforce and its well-established universal health care system, is well positioned to enact changes to shift its current approach to STI prevention, treatment, and control. STI control based on highlighting behavioral, social, cultural, and environmental influences on service members' sexual health and wellness may well drive better STI care and prevention outcomes.

Military and Civilian Sector Practice Patterns for Short-Term Travelers' Diarrhea Self-Treatment in Adults

The Deployment and Travel Medicine Knowledge, Attitude, Practice and Outcomes Study investigates the various clinician and traveler contributions to medical outcomes within the U.S. Military Health System. Travelers' diarrhea is among the most common travel-related illnesses, making travelers' diarrhea self-treatment (TDST) important for traveler health. A cohort of 80,214 adult travelers receiving malaria chemoprophylaxis for less than 6 weeks of travel were identified within the U.S. Department of Defense Military Health System Data Repository. Associated prescriptions for TDST medications within 2 weeks of chemoprophylaxis prescriptions were identified. Prescription patterns were compared by service member versus beneficiary status and site of care, military facility versus civilian facility. At military facilities, medical provider demographics were analyzed by clinical specialty and categorized as travel medicine specialists versus nonspecialists. Overall, there was low prescribing of TDST, particularly among civilian providers and military nonspecialists, despite guidelines recommending self-treatment of moderate to severe travelers' diarrhea. This practice gap was largest among service member travelers, but also existed for beneficiaries. Compared with nonspecialists, military travel medicine specialists were more likely to prescribe a combination of an antibiotic and antimotility agent to beneficiaries, more likely to provide any form of TDST to service members, and more likely to prescribe azithromycin than quinolones when using antibiotics. Our study suggests that enhancing provider knowledge and use of travelers' diarrhea treatment recommendations combined with improved access to formal travel medicine services may be important to increase the quality of care.

A Comparative Analysis of Reported Chlamydia and Gonorrhea Cases Among US Army Soldiers, 2015 to 2019

BACKGROUND

Chlamydia and gonorrhea have increased nationally and in the US Army. Rates reported in the Army are elevated relative to the general population, partly because of differing population demographics.

METHODS

Age- and sex-specific chlamydia and gonorrhea case rates among Army active component soldiers and the wider 18- to 64-year-old US adult population were computed from reports submitted through national and military surveillance systems in 2015 to 2019. Rates were standardized using the 2015 Army age and sex population distribution. Multivariable generalized linear models were generated to evaluate associated risk factors.

RESULTS

Army age- and sex-adjusted chlamydia rates (per 100,000 person-years) were nearly twice those of US adults (2019 rates, 2317 vs. 1241), whereas US age- and sex-adjusted gonorrhea rates surpassed Army rates (2019 rates, 536 vs. 396). Chlamydia and gonorrhea rates were significantly elevated in Army women younger than 25 years relative to US women aged 18 to 24 years (2015-2019 crude rates, 10,404 Army/4243 US for chlamydia and 1014 Army/694 US for gonorrhea). Gonorrhea rates were significantly elevated in US men aged 25 to 44 years (2015-2019 crude rates, 506 US/251 Army and 223 US/86 Army for men aged 25-34 and 35-44 years, respectively). Age, sex, and race-ethnicity were significantly associated with infection among soldiers.

CONCLUSIONS

Observed increases in chlamydia and gonorrhea and identified risk factors are consistent with those reported nationally. Higher adjusted chlamydia rates among soldiers may reflect greater individual or sexual network risks, screening biases, or increased health care access. The Army's lower adjusted gonorrhea rates may reflect differences in high-risk subgroups (e.g., men who have sex with men), differing sexual networks, or other confounders.

Identifying Nontraditional Epidemic Disease Risk Factors Associated with Major Health Events from World Health Organization and World Bank Open Data

Health events emerge from host, community, environment, and pathogen factors-forecasting epidemics is a complex task. We describe an exploratory analysis to identify economic risk factors that could aid epidemic risk assessment. A line list was constructed using the World Health Organization Disease Outbreak News (2016-2018) and economic indicators from the World Bank. Poisson regression employing forward imputations was used to establish relationships with the frequency with which countries reported public health events. Economic indicators demonstrated strong performance appropriate for further assessment in surveillance programming. In our analysis, three economic indicators were significantly associated to event reporting: how much the country's urban population changed, its average forest area, and a novel economic indicator we developed that assessed how much the gross domestic product changed per capita. Other economic indicators performed less well: changes in total, female, urban, and rural population sizes; population density; net migration; change in per cent forest area; total forest area; and another novel indicator, change in percent of trade as a fraction of the total economy. We then undertook a further analysis of the start of the current COVID-19 pandemic that revealed similar associations, but confounding by global disease burden is likely. Continued development of forecasting approaches capturing information relevant to whole-of-society factors (e.g., economic factors as assessed in our study) could improve the risk management process through earlier hazard identification and inform strategic decision processes in multisectoral strategies to preventing, detecting, and responding to pandemic-threat events.

Outcomes From U.S. Military-Supported Overseas Training Rotations in Tropical Medicine and Global Health, 2006-2015

BACKGROUND

Since 2006, the Division of Tropical Public Health at the Uniformed Services University (USU) has sponsored the Tropical Medicine Training Program (TMTP). Despite practice guidelines stating that global health education should include the collection and evaluation of data on the impact of the training experiences, no quantitative evaluation of program outcomes had previously occurred. The objective of this report was to evaluate TMTP outcomes to guide program improvement.

METHODS

We developed an anonymous, web-based survey to assess program outcomes as part of routine program evaluation. The survey addressed four main areas of potential TMTP impact: (1) career engagement, (2) military service contributions, (3) scholarly activity, and (4) acquisition of knowledge and skills. In February 2016, we sent the survey electronically to 222 program participants between Fiscal Years 2006 and 2015 who had e-mails available in DoD administrative systems.

FINDINGS

Ninety-eight (44%) of these responded to the survey. TMTP demonstrated impact in several areas. Increased knowledge and skills were reported by 81% of trainees, and 70% reported increased interest in serving at military overseas medical research laboratories. Subsequent career engagement by trainees included seven assignments to overseas research laboratories, 71 military deployments, and 193 short-term military missions. The ability to achieve many of the desired outcomes was associated with time elapsed since completion of formal medical education, including 24% who were still enrolled in graduate medical education.

DISCUSSION/IMPACT/RECOMMENDATIONS

The TMTP has improved the U.S. military's ability to perform surveillance for emerging tropical and infectious diseases and has contributed to force health protection and readiness. Although many of the outcomes, such as service in the overseas research laboratories and military deployments, are dependent on military service requirements, these results remain perhaps the most relevant ways that the TMTP meets global health requirements of the US military and the nation. Additional outcomes from this training are expected to accrue as these participants complete their medical postgraduate training programs.

Survey of Sexually Transmitted Disease Laboratory Methods in U.S. Army Laboratories, 2012

INTRODUCTION

Sexually transmitted diseases (STD) affect primarily young people (17-24 years). The U.S. Military, with many young people, strives to maintain effective STD treatment and prevention programs using current methods. Laboratory testing technology and capacity are important for appropriate clinical management and to provide data to direct prevention programs. STD laboratory capabilities are assessed in civilian and military laboratories using surveys. An Army laboratory survey was conducted in 2007. The Army laboratory survey reported here was conducted on 2012 to describe STD tests done, laboratory testing practices, and testing volume to include the use of human immunodeficiency virus point-of-care tests and a novel reverse syphilis testing algorithm.

MATERIALS AND METHODS

A web-based survey was offered to all 32 Army laboratories in 2013 to assess testing in 2012. Twenty-two laboratories (69%), including all medical center laboratories, completed the survey. The survey was approved by the U.S. Army Human Protection Review Board.

RESULTS

The Army laboratories reported testing more than 230,000 specimens for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), with 82% and 86% using nucleic acid amplification test (NAAT) methods for CT and NG, respectively. Eleven laboratories (50%) performed combined NAAT methods for CT and NG. Four (18%) performed NG antimicrobial susceptibility testing. Two (10%) screened for syphilis using the reverse algorithm. All offered in-house wet-mount microscopy for Trichomonas vaginalis. Thirteen (62%) used rapid human immunodeficiency virus testing.

CONCLUSION

Comparing the 2012 results to the 2007 Army survey results, use of NAAT methods remained relatively stable while antimicrobial NG susceptibility testing decreased. Efforts to promote NAAT methods, to include testing vaginal and nongenital specimens for CT and NG, must continue. NG antibiotic resistance testing should be increased. Monitoring the use of the reverse syphilis screening algorithm is recommended to assess the impact of false-positive results.

Rates of Chlamydia trachomatis infections across the deployment cycle, active component, U.S. Armed Forces, 2008-2015

High rates of sexually transmitted infections (STIs), including Chlamydia trachomatis (CT), have been documented among U.S. military service members. However, it is unknown whether phases of the deployment cycle affect risk for CT. This article characterizes the rates of CT infections during the predeployment, deployment, and post-deployment phases for active component members of the U.S. Army, Navy, Air Force, and Marine Corps during 2008-2015. Cases of CT were defined using laboratory, reportable medical event, and prescription data in a sensitivity analysis approach. Adjusted incidence rate ratios for CT were calculated using a multivariable Poisson model. In these analyses, the crude and adjusted incidence rates of CT were found to be highest during the pre-deployment phase for both sexes. However, men's rates of CT differed only slightly across pre-, post-, and non-deployed phases, while women had substantial rate differences between phases. These analyses call for better screening and documentation of STIs during deployment, as well as continued surveillance of STIs in the Military Health System, to assess the true burden of disease.

Expedited Partner Therapy to Combat Neisseria gonorrhoeae and Chlamydia trachomatis in Military Populations: Can We Apply This Best Practice?

Expedited Partner Therapy (EPT) is the practice of treating the partners of patients with sexually transmitted infections by providing medications for the patient to deliver to his or her sexual partner (s) without direct clinical assessment of the partner(s). EPT is an evidence-based option that can augment existing partner management strategies. For military health care providers, questions still loom as to the pragmatic medical, legal, and ethical uncertainties of EPT use in military populations. These issues, in addition to the absence of an explicit Department of Defense EPT policy may dissuade military clinicians from fully employing EPT to prevent reinfection and inhibit additional disease transmission in their patients. To advance the notion that EPT could not only be an efficient but also a vital measure to decrease the high sexually transmitted disease burden, this report highlights existing approaches utilized by military providers to treat partners of patients diagnosed with chlamydia and/or gonorrhea, benefits of using EPT in military populations, and specific challenges of implementing an EPT program. This report asserts that now is the time to "push the conversation" on the use of EPT as a viable choice for military providers.

Knowledge, attitudes, and beliefs about HIV pre-exposure prophylaxis among US Air Force Health Care Providers

Providers are central to effective implementation of HIV pre-exposure prophylaxis (PrEP). Primary care providers (PCP) and infectious disease physicians (ID) in the US Air Force (USAF) participated in a cross-sectional survey regarding knowledge, attitudes, and beliefs toward HIV PrEP. Characteristics associated with PrEP knowledge were assessed in univariate and multivariate analyses.Among 403 (40% of 1015 providers) participants, 9% (PCP 383, ID 20) ever prescribed PrEP. In univariate analysis, years in practice, number of HIV-infected patients treated in the past 12 months, past prescription of antiretrovirals for HIV prevention, frequency of prescribing PrEP in the past 12 months, and ever being questioned by a patient about PrEP were associated with PrEP knowledge (P < 0.05). In multivariate analysis, providers who had ever prescribed antiretrovirals to prevent HIV (AOR: 2.37, 95% CI: 1.27-4.42) had greater odds of high PrEP knowledge. Despite concerns about medication side effects (overall 67%: PCP 68%, ID 85%) and prescribing PrEP without clear evidence (overall 60%: PCP 65%, ID 62%), 64% (PCP 65%, ID 85%) of participants indicated PrEP should be offered in the Military Health System and 68% (PCP 70%, ID 100%) disagreed with the statement that their patient population was not at risk for HIV infection.Successful PrEP implementation in the USAF will require continued education and training of primary care providers to improve knowledge and mitigate concerns about PrEP.

Select Public Health and Communicable Disease Lessons Learned During Operations Iraqi Freedom and Enduring Freedom

History has taught us that the threat of communicable diseases to operational readiness should not be underestimated. The unique operational challenges of a decade at war in Southwest Asia have left us with many new lessons about prevention and mitigation of disease. The successes of military immunization programs demonstrated the successful application of military science to modern combat. Historic maladies such as tuberculosis and malaria continue to challenge our Army health leadership while new challenges with diseases like Q fever and rabies led to questions about our preparedness. These conflicts also brought awareness of issues about the broader deployed community, and the often unique risks that arise when US service members interact more frequently with foreign militaries, local nationals, and third country nationals. Application of these lessons to predeployment training and integration into leadership decision-making will improve our ability to maintain force readiness in future conflicts and adapt Army policy to current evidence and intelligence.

The U.S. military's Neisseria gonorrhoeae resistance surveillance initiatives in selected populations of five countries

Multi-drug resistant Neisseria gonorrhoeae (GC) threatens the successful treatment of gonorrhea. This report presents preliminary findings with regard to the prevalence of laboratory-confirmed GC and the extent of drug-resistance among sample populations in five countries. Between October 2010 and January 2013, 1,694 subjects (54% male; 45% female; 1% unknown) were enrolled and screened for the presence of laboratory-confirmed GC in the United States, Djibouti, Ghana, Kenya, and Peru. Overall, 108 (6%) of enrolled subjects tested positive for GC. Antimicrobial susceptibility testing results were available for 66 GC isolates. Resistance to at least three antibiotics was observed at each overseas site. All isolates tested in Ghana (n=6) were resistant to ciprofloxacin, penicillin, and tetracycline. In Djibouti, preliminary results suggested resistance to penicillin, tetracycline, ciprofloxacin, cefepime, and ceftriaxone. The small sample size and missing data prevent comparative analysis and limit the generalizability of these preliminary findings.

Confirmed malaria cases among active component U.S. Army personnel, January-September 2012

Of 26 cases of malaria reported among active component U.S. Army personnel during January through September 2012, 16 were laboratory-confirmed according to electronic medical records. Medical records and responses on postdeployment health assessment questionnaires were used to assess demographic and clinical characteristics, adherence to malaria prevention measures, and compliance with prescriptions for chemoprophylaxis. All but two cases were confirmed by peripheral blood smears. Twelve cases were caused by Plasmodium vivax, one by P. falciparum, and three unspecified diagnoses were deemed likely to be due to P. vivax. Fourteen cases were associated with deployment to Afghanistan. Adherence to Army malaria prevention measures during deployment and compliance with post-deployment primaquine chemprophylaxis were poor. Prescribed doses of primaquine often varied from current clinical or Department of Defense policy guidelines. Continued education, training and reinforcement of malaria prevention by medical and preventive medicine personnel are indicated, as is blood smear confirmation of suspected malaria cases. Unit commanders and supervisors play a crucial role in ensuring soldiers' adherence to malaria prevention measures.