Clotting factor genes are associated with preeclampsia in high-altitude pregnant women in the Peruvian Andes.

Preeclampsia is a multi-organ complication of pregnancy characterized by sudden hypertension and proteinuria that is among the leading causes of preterm delivery and maternal morbidity and mortality worldwide. The heterogeneity of preeclampsia poses a challenge for understanding its etiology and molecular basis. Intriguingly, risk for the condition increases in high-altitude regions such as the Peruvian Andes. To investigate the genetic basis of preeclampsia in a population living at high altitude, we characterized genome-wide variation in a cohort of preeclamptic and healthy Andean families (n = 883) from Puno, Peru, a city located above 3,800 meters of altitude. Our study collected genomic DNA and medical records from case-control trios and duos in local hospital settings. We generated genotype data for 439,314 SNPs, determined global ancestry patterns, and mapped associations between genetic variants and preeclampsia phenotypes. A transmission disequilibrium test (TDT) revealed variants near genes of biological importance for placental and blood vessel function. The top candidate region was found on chromosome 13 of the fetal genome and contains clotting factor genes PROZ, F7, and F10. These findings provide supporting evidence that common genetic variants within coagulation genes play an important role in preeclampsia. A selection scan revealed a potential adaptive signal around the ADAM12 locus on chromosome 10, implicated in pregnancy disorders. Our discovery of an association in a functional pathway relevant to pregnancy physiology in an understudied population of Native American origin demonstrates the increased power of family-based study design and underscores the importance of conducting genetic research in diverse populations.

Who Transmits Tuberculosis to Whom: A Cross-Sectional Analysis of a Cohort Study in Lima, Peru.

Rationale: The persistent burden of tuberculosis (TB) disease emphasizes the need to identify individuals with TB for treatment and those at a high risk of incident TB for prevention. Targeting interventions toward those at high risk of developing and transmitting TB is a public health priority. Objectives: We aimed to identify characteristics of individuals involved in TB transmission in a community setting, which may guide the prioritization of targeted interventions. Methods: We collected clinical and sociodemographic data from a cohort of patients with TB in Lima, Peru. We used whole-genome sequencing data to assess the genetic distance between all possible pairs of patients; we considered pairs to be the result of a direct transmission event if they differed by three or fewer SNPs, and we assumed that the first diagnosed patient in a pair was the transmitter and the second was the recipient. We used logistic regression to examine the association between host factors and the likelihood of direct TB transmission. Measurements and Main Results: Analyzing data from 2,518 index patients with TB, we identified 1,447 direct transmission pairs. Regardless of recipient attributes, individuals less than 34 years old, males, and those with a history of incarceration had a higher likelihood of being transmitters in direct transmission pairs. Direct transmission was more likely when both patients were drinkers or smokers. Conclusions: This study identifies men, young adults, former prisoners, alcohol consumers, and smokers as priority groups for targeted interventions. Innovative strategies are needed to extend TB screening to social groups such as young adults and prisoners with limited access to routine preventive care.

Spatial scale of tuberculosis transmission in Lima, Peru.

Spatially targeted interventions may be effective alternatives to individual or population-based prevention strategies against tuberculosis (TB). However, their efficacy may depend on the mechanisms that lead to geographically constrained hotspots. Local TB incidence may reflect high levels of local transmission; conversely, they may point to frequent travel of community members to high-risk areas. We used whole-genome sequencing to explore patterns of TB incidence and transmission in Lima, Peru. Between 2009 and 2012, we recruited incident pulmonary TB patients and their household contacts, whom we followed for the occurrence of TB disease. We used whole-genome sequences of 2,712 Mycobacterial tuberculosis isolates from 2,440 patients to estimate pariwise genomic distances and compared these to the spatial distance between patients' residences. Genomic distances increased rapidly as spatial distances increased and remained high beyond 2 km of separation. Next, we divided the study catchment area into 1 × 1 km grid-cell surface units and used household spatial coordinates to locate each TB patient to a specific cell. We estimated cell-specific transmission by calculating the proportion of patients in each cell with a pairwise genomic distance of 10 or fewer single-nucleotide polymorphisms. We found that cell-specific TB incidence and local transmission varied widely but that cell-specific TB incidence did not correlate closely with our estimates of local transmission (Cohen's k = 0.27). These findings indicate that an understanding of the spatial heterogeneity in the relative proportion of TB due to local transmission may help guide the implementation of spatially targeted interventions.

Efficacy of a spatial repellent for control of Aedes-borne virus transmission: A cluster-randomized trial in Iquitos, Peru.

Over half the world's population is at risk for viruses transmitted by Aedes mosquitoes, such as dengue and Zika. The primary vector, Aedes aegypti, thrives in urban environments. Despite decades of effort, cases and geographic range of Aedes-borne viruses (ABVs) continue to expand. Rigorously proven vector control interventions that measure protective efficacy against ABV diseases are limited to Wolbachia in a single trial in Indonesia and do not include any chemical intervention. Spatial repellents, a new option for efficient deployment, are designed to decrease human exposure to ABVs by releasing active ingredients into the air that disrupt mosquito-human contact. A parallel, cluster-randomized controlled trial was conducted in Iquitos, Peru, to quantify the impact of a transfluthrin-based spatial repellent on human ABV infection. From 2,907 households across 26 clusters (13 per arm), 1,578 participants were assessed for seroconversion (primary endpoint) by survival analysis. Incidence of acute disease was calculated among 16,683 participants (secondary endpoint). Adult mosquito collections were conducted to compare Ae. aegypti abundance, blood-fed rate, and parity status through mixed-effect difference-in-difference analyses. The spatial repellent significantly reduced ABV infection by 34.1% (one-sided 95% CI lower limit, 6.9%; one-sided P value = 0.0236, z = 1.98). Aedes aegypti abundance and blood-fed rates were significantly reduced by 28.6 (95% CI 24.1%, ∞); z = -9.11) and 12.4% (95% CI 4.2%, ∞); z = -2.43), respectively. Our trial provides conclusive statistical evidence from an appropriately powered, preplanned cluster-randomized controlled clinical trial of the impact of a chemical intervention, in this case a spatial repellent, to reduce the risk of ABV transmission compared to a placebo.

Changes in Inflammatory Cytokine Levels in Rectal Mucosa Associated With Neisseria gonorrheae and/or Chlamydia trachomatis Infection and Treatment Among Men Who Have Sex With Men in Lima, Peru.

BACKGROUND: Neisseria gonorrheae and Chlamydia trachomatis are associated with mucosal inflammation and human immunodeficiency virus 1 (HIV-1) transmission. We assessed levels of inflammatory cytokines in men who have sex with men (MSM) with and without rectal gonorrhea and/or chlamydia in Lima, Peru. METHODS: We screened 605 MSM reporting condomless receptive anal intercourse for rectal N. gonorrheae/C. trachomatis using nucleic acid testing. We identified 101 cases of gonorrhea and/or chlamydia and randomly selected 50 N. gonorrheae/C. trachomatis positive cases and matched 52 negative controls. We measured levels of IL-1ß, IL-6, IL-8, and TNF-α in rectal secretions. Tests for HIV-1, rectal N. gonorrheae/C. trachomatis, and mucosal cytokines were repeated after 3 and 6 months. Cytokine levels in cases and uninfected controls were compared using Wilcoxon rank-sum tests and linear regression. RESULTS: MSM with gonorrhea/chlamydia had elevated levels of all cytokines in rectal mucosa compared with matched controls (all P values <.001). Following antibiotic treatment there were no significant differences in cytokine levels at 3- or 6-month follow-up evaluations (all P values >.05). DISCUSSION: Rectal gonorrhea/chlamydia infection is associated with transient mucosal inflammation and cytokine recruitment. Our data provide proof of concept for rectal sexually transmitted infection screening as an HIV prevention strategy for MSM. Clinical Trials Registration. NCT03010020.

Fort Sherman Virus Infection in Human, Peru, 2020.

Fort Sherman virus (FSV) was isolated in Panama in 1985 from a US soldier. We report a case of human FSV infection in a febrile patient from northern coastal Peru in 2020. FSV infections spanning ≈35 years and a distance of 2,000 km warrant diagnostics, genomic surveillance, and investigation of transmission cycles.

Chest Radiograph Screening for Detecting Subclinical Tuberculosis in Asymptomatic Household Contacts, Peru.

The World Health Organization's end TB strategy promotes the use of symptom and chest radiograph screening for tuberculosis (TB) disease. However, asymptomatic early states of TB beyond latent TB infection and active disease can go unrecognized using current screening criteria. We conducted a longitudinal cohort study enrolling household contacts initially free of TB disease and followed them for the occurrence of incident TB over 1 year. Among 1,747 screened contacts, 27 (52%) of the 52 persons in whom TB subsequently developed during follow-up had a baseline abnormal radiograph. Of contacts without TB symptoms, persons with an abnormal radiograph were at higher risk for subsequent TB than persons with an unremarkable radiograph (adjusted hazard ratio 15.62 [95% CI 7.74-31.54]). In young adults, we found a strong linear relationship between radiograph severity and time to TB diagnosis. Our findings suggest chest radiograph screening can extend to detecting early TB states, thereby enabling timely intervention.

Phase 3 Safety and Efficacy of AZD1222 (ChAdOx1 nCoV-19) Covid-19 Vaccine.

BACKGROUND: The safety and efficacy of the AZD1222 (ChAdOx1 nCoV-19) vaccine in a large, diverse population at increased risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the United States, Chile, and Peru has not been known. METHODS: In this ongoing, double-blind, randomized, placebo-controlled, phase 3 clinical trial, we investigated the safety, vaccine efficacy, and immunogenicity of two doses of AZD1222 as compared with placebo in preventing the onset of symptomatic and severe coronavirus disease 2019 (Covid-19) 15 days or more after the second dose in adults, including older adults, in the United States, Chile, and Peru. RESULTS: A total of 32,451 participants underwent randomization, in a 2:1 ratio, to receive AZD1222 (21,635 participants) or placebo (10,816 participants). AZD1222 was safe, with low incidences of serious and medically attended adverse events and adverse events of special interest; the incidences were similar to those observed in the placebo group. Solicited local and systemic reactions were generally mild or moderate in both groups. Overall estimated vaccine efficacy was 74.0% (95% confidence interval [CI], 65.3 to 80.5; P<0.001) and estimated vaccine efficacy was 83.5% (95% CI, 54.2 to 94.1) in participants 65 years of age or older. High vaccine efficacy was consistent across a range of demographic subgroups. In the fully vaccinated analysis subgroup, no severe or critical symptomatic Covid-19 cases were observed among the 17,662 participants in the AZD1222 group; 8 cases were noted among the 8550 participants in the placebo group (<0.1%). The estimated vaccine efficacy for preventing SARS-CoV-2 infection (nucleocapsid antibody seroconversion) was 64.3% (95% CI, 56.1 to 71.0; P<0.001). SARS-CoV-2 spike protein binding and neutralizing antibodies increased after the first dose and increased further when measured 28 days after the second dose. CONCLUSIONS: AZD1222 was safe and efficacious in preventing symptomatic and severe Covid-19 across diverse populations that included older adults. (Funded by AstraZeneca and others; ClinicalTrials.gov number, NCT04516746.).

Unveiling Melanoma: A Deep Dive into Disparities at a Latin-American Cancer Institute.

INTRODUCTION: The worldwide incidence of melanoma has increased in the last 40 years. Our aim was to describe the clinic-pathological characteristics and outcomes of three cohorts of patients diagnosed with melanoma in a Latin-American cancer institute during the last 20 years. METHODS: We evaluated three retrospective patient cohorts diagnosed with melanoma at Instituto Nacional de Enfermedades Neoplasicas (INEN), a public hospital in Lima, Peru, for the years 2005-2006, 2010-2011, and 2017-2018. Survival rate differences were assessed using the Log-rank test. RESULTS: Overall, 584 patients were included (only trunk and extremities); 51% were male, the mean age was 61 (3-97) years, and 48% of patients resided in rural areas. The mean time to diagnosis was 22.6 months, and the mean Breslow thickness was 7.4 mm (T4). Lower extremity was the most common location (72%). A majority of the patients (55%) had metastases at the time of presentation, with 36% in stage III and 19% in stage IV. Cohorts were distributed as 2005-2006 (n = 171), 2010-2011 (n = 223), and 2017-2018 (n = 190). No immunotherapy was used. Cohort C exhibited the most significant increase in stage IV diagnoses (12.3%, 15.7%, 28.4%, respectively; p < 0.01). The median overall survival rates at the three-year follow-up demonstrated a decline over the years for stages II (97%, 98%, 57%, respectively; p < 0.05) and III (66%, 77%, 37%; p < 0.01). CONCLUSIONS: There has been a worsening in the incidence of late-stage metastatic melanoma in Peru throughout the years, coupled with a significant decline in overall survival rates. This is underscored by the fact that half of the population lives in regions devoid of oncological access.

Sexual network characteristics and partnership types among men who have sex with men diagnosed with syphilis, gonorrhoea and/or chlamydia in Lima, Peru.

OBJECTIVES: Sexual networks are known to structure sexually transmitted infection (STI) transmission among men who have sex with men (MSM). We sought to estimate the risks of STI diagnosis for various partnership types within these networks. METHODS: Our cross-sectional survey analysed data from 1376 MSM screened for a partner management intervention in Lima, Peru. Participants were tested for HIV, syphilis, gonorrhoea (NG) and chlamydia (CT) and completed surveys on their demographics, sexual identity/role, HIV status, partnership types and sexual network from the prior 90 days. χ2 and Wilcoxon rank-sum tests compared participants without an STI to those diagnosed with (1) syphilis, (2) NG and/or CT (NG/CT) and (3) syphilis and NG/CT coinfection (coinfection). RESULTS: 40.8% (n=561/1376) of participants were diagnosed with an STI (syphilis: 14.9%, NG/CT: 16.4%, coinfection: 9.5%). 47.9% of all participants were living with HIV and 8.9% were newly diagnosed. A greater proportion of participants with syphilis and coinfection were living with HIV (73.5%, p<0.001; 71.0%, p<0.001) compared with those with NG/CT (47.8%) or no STI (37.8%). Participants with syphilis more often reported sex-on-premises venues (SOPVs) as the location of their last sexual encounter (51.7%, p=0.038) while those with NG/CT tended to meet their last sexual partner online (72.8%, p=0.031). Respondents with coinfection were the only STI group more likely to report transactional sex than participants without an STI (31.3%, p=0.039). CONCLUSIONS: Sexual networks and partnership types of Peruvian MSM are associated with differential risks for STIs. Participants diagnosed with syphilis tended to meet single-encounter casual partners at SOPV, while MSM with NG/CT were younger and often contacted casual partners online. Coinfection had higher frequency of transactional sex. These findings suggest the potential importance of public health interventions through combined syphilis/HIV screening at SOPV, syphilis screening at routine clinic appointments for MSM living with HIV and directed advertisements and/or access to NG/CT testing through online platforms.

HIV Infection Modifies the Role of Prior Treponema pallidum Infection in the Clinical Presentation of Early Syphilis Among Adult Patients From Sexually Transmitted Infection Clinics in Peru.

BACKGROUND: We aimed to compare the clinical presentations (symptomatic vs. asymptomatic) with prior Treponema pallidum infection status (first infection vs. reinfection) among people with early syphilis. METHODS: We used data from PICASSO, a cohort study in Peru that enrolled people with active syphilis from May 2019 to August 2021. Study participants had early syphilis and a prior syphilis serological test result within the prior 12 months to determine prior T. pallidum infection status. We calculated prevalence ratios (PRs) of symptomatic clinical presentation (primary or secondary syphilis) by prior T. pallidum infection status, stratified by HIV infection status. In addition, we explored the association of prior T. pallidum infection status and lesion presentation, stratified by primary and secondary syphilis cases, using the Fisher exact test. RESULTS: We include 84 T. pallidum reinfection cases and 61 first infection cases. We found increased frequency of symptomatic clinical presentation among first-infection cases (39% vs. 20%; PR, 1.94; P = 0.014). This association was stronger among persons living without HIV infection (38% vs. 7%; adjusted PR, 6.63; P = 0.001) in comparison to those living with HIV infection (45% vs. 34%; adjusted PR, 1.38; P = 0.458). Among secondary syphilis cases, more participants from the reinfection group reported that their lesions improved 1 week after treatment (100% vs. 29%, P = 0.045) compared with those with a first infection. Among the primary syphilis cases, all participants reported that their lesions improved 1 week after treatment. CONCLUSIONS: Prior syphilis was associated with a decreased prevalence of symptomatic reinfection, especially among persons not living with HIV infection.

Proportion of cancer cases and deaths attributable to potentially modifiable risk factors in Peru.

BACKGROUND: Limited evidence exists on the population attributable fraction (PAF) of cancer cases and deaths in Latin America. In Peru several studies have been published regarding the PAF of various risk factors and their associated diseases. The objective of this study was to estimate the fraction of cancer cases and deaths attributable to potentially modifiable risk factors in Peru in 2018, before the COVID-19 pandemic in the population of 15 years old and older. METHODS: An ecological study was conducted using the prevalence of exposure of the Peruvian population to modifiable risk factors for cancer, the relative risk associated with each factor, and the number of cancer cases and deaths in 2018 as inputs. We used the Parkin formula with a Montecarlo statistical simulation model to calculate the PAF and confidence intervals. The number of new cancer cases and deaths attributed to each risk factor was determined by multiplying the number of cases and deaths in each gender by the PAF of each risk factor. FINDINGS: In Peru, 38.5% of new cases (34.5% in men and 42% in women) and 43.4% of cancer-related deaths (43.4% in men and 43.4% in women) were attributable to modifiable risk factors. The number of cancers attributable was 25,308 (10,439 in men and 14,869 in women) and the number of deaths attributable to cancer was 14,839 (6,953 in men and 7,886 in women). The predominant modifiable risk factors contributing to the highest number of cases and deaths were HPV infection (4,563 cases, 2,409 deaths), current tobacco use (3,348 cases, 2,180 deaths), and helicobacter pylori infection (2,677 cases, 1,873 deaths). Among the risk factors, oncogenic infections constituted the group with the highest PAF (16.6% for cases, 19.2% for deaths) followed by other unhealthy lifestyle factors (14.2% for cases, 16.7% for deaths), tobacco (7.2% for cases, 7.2% for deaths) and ultraviolet radiation (0.5% for cases, 0.3% for deaths). CONCLUSIONS: Prior to the COVID-19 pandemic, 38.5% of cancer cases and 43.4% of cancer-related deaths in Peru were linked to modifiable risk factors in the population of 15 years old and older. Most preventable cancer cases and deaths were related to oncogenic infections, primarily caused by HPV and helicobacter pylori, followed by tobacco and obesity.

Impact of the COVID-19 Pandemic on the Treatment of Cancer Patients at a Hospital in Peru.

BACKGROUND: The appearance of the new coronavirus, SARS-CoV-2, in Wuhan - China, in 2019 led to the declaration of a COVID-19 pandemic by the World Health Organization. Peru confirmed its first case on March 6, 2020, prompting a significant change in medical care. PURPOSE: Our objective was to determine the impact of the COVID-19 pandemic on cancer treatment in Peru. METHODS: A retrospective analysis of hospital data from the National Institute of Neoplastic Diseases revealed substantial decreases in oncological treatments in 2020 compared to 2019. RESULTS: Oncological treatments involving bone marrow transplantation had a greater impact between the months of April and September, at -100% (p=0.003). However, treatments involving surgery in April (-95% [p≤0.001]), radiotherapy in May (-76% [p=0.002]) and chemotherapy in June (-71% [p≤0.001]) also showed significant impacts. Comparative analysis with international data revealed similar trends in cancer care interruptions in different countries. However, variations in the magnitude of the impact were observed, influenced by regional health policies and the severity of the pandemic. CONCLUSIONS: The findings underscore the challenges cancer care providers face during public health crises, requiring adaptive strategies to ensure continued access to essential treatments. Addressing these challenges requires comprehensive public health responses to mitigate the impact of future crises on cancer care systems.

Evaluation of naturally acquired immune responses against novel pre-erythrocytic Plasmodium vivax proteins in a low endemic malaria population located in the Peruvian Amazon Basin.

BACKGROUND: Plasmodium vivax represents the most geographically widespread human malaria parasite affecting civilian and military populations in endemic areas. Targeting the pre-erythrocytic (PE) stage of the parasite life cycle is especially appealing for developing P. vivax vaccines as it would prevent disease and transmission. Here, naturally acquired immunity to a panel of P. vivax PE antigens was explored, which may facilitate vaccine development and lead to a better understanding of naturally acquired PE immunity. METHODS: Twelve P. vivax PE antigens orthologous to a panel of P. falciparum antigens previously identified as highly immunogenic in protected subjects after immunization with radiation attenuated sporozoites (RAS) were used for evaluation of humoral and cellular immunity by ELISA and IFN-γ ELISpot. Samples from P. vivax infected individuals (n = 76) from a low endemic malaria region in the Peruvian Amazon Basin were used. RESULTS: In those clinical samples, all PE antigens evaluated showed positive IgG antibody reactivity with a variable prevalence of 58-99% in recently P. vivax diagnosed patients. The magnitude of the IgG antibody response against PE antigens was lower compared with blood stage antigens MSP1 and DBP-II, although antibody levels persisted better for PE antigens (average decrease of 6% for PE antigens and 43% for MSP1, p < 0.05). Higher IgG antibodies was associated with one or more previous malaria episodes only for blood stage antigens (p < 0.001). High IgG responders across PE and blood stage antigens showed significantly lower parasitaemia compared to low IgG responders (median 1,921 vs 4,663 par/µl, p < 0.05). In a subgroup of volunteers (n = 17),positive IFN-γ T cell response by ELISPOT was observed in 35% vs 9-35% against blood stage MSP1 and PE antigens, respectively, but no correlation with IgG responses. CONCLUSIONS: These results demonstrate clear humoral and T cell responses against P. vivax PE antigens in individuals naturally infected with P. vivax. These data identify novel attractive PE antigens suitable for use in the potential development and selection of new malaria vaccine candidates which can be used as a part of malaria prevention strategies in civilian and military populations living in P. vivax endemic areas.

Effect of spatiotemporal variables on abundance, biting activity and parity of Nyssorhynchus darlingi (Diptera: Culicidae) in peri-Iquitos, Peru.

BACKGROUND: In malaria endemic regions of the Peruvian Amazon, rainfall together with river level and breeding site availability drive fluctuating vector mosquito abundance and human malaria cases, leading to temporal heterogeneity. The main variables influencing spatial transmission include location of communities, mosquito behaviour, land use/land cover, and human ecology/behaviour. The main objective was to evaluate seasonal and microgeographic biting behaviour of the malaria vector Nyssorhynchus (or Anopheles) darlingi in Amazonian Peru and to investigate effects of seasonality on malaria transmission. METHODS: We captured mosquitoes from 18:00 to 06:00 h using Human Landing Catch in two riverine (Lupuna, Santa Emilia) and two highway (El Triunfo, Nuevo Horizonte) communities indoors and outdoors from 8 houses per community, during the dry and rainy seasons from February 2016 to January 2017. We then estimated parity rate, daily survival and age of a portion of each collection of Ny. darlingi. All collected specimens of Ny. darlingi were tested for the presence of Plasmodium vivax or Plasmodium falciparum sporozoites using real-time PCR targeting the small subunit of the 18S rRNA. RESULTS: Abundance of Ny. darlingi varied across village, season, and biting behaviour (indoor vs outdoor), and was highly significant between rainy and dry seasons (p < 0.0001). Biting patterns differed, although not significantly, and persisted regardless of season, with peaks in highway communities at ~ 20:00 h in contrast to biting throughout the night (i.e., 18:00-06:00) in riverine communities. Of 3721 Ny. darlingi tested for Plasmodium, 23 (0.62%) were infected. We detected Plasmodium-infected Ny. darlingi in both community types and most (20/23) were captured outdoors during the rainy season; 17/23 before midnight. Seventeen Ny. darlingi were infected with P. vivax, and 6 with P. falciparum. No infected Ny. darlingi were captured during the dry season. Significantly higher rates of parity were detected in Ny. darlingi during the rainy season (average 64.69%) versus the dry season (average 36.91%) and by community, Lupuna, a riverine village, had the highest proportion of parous to nulliparous females during the rainy season. CONCLUSIONS: These data add a seasonal dimension to malaria transmission in peri-Iquitos, providing more evidence that, at least locally, the greatest risk of malaria transmission is outdoors during the rainy season mainly before midnight, irrespective of whether the community was located adjacent to the highway or along the river.

Knowledge, attitudes, and practices regarding malaria transmission and prevention in an indigenous Maijuna community: a qualitative study in the Peruvian Amazon.

BACKGROUND: Peru is a low-endemic transmission area for malaria, where the majority (84%) of incident malaria cases are localized to the department of Loreto, which is composed of several geographically isolated rural communities. Recent intervention efforts targeting at-risk Indigenous populations that live in riverine communities in Loreto place emphasis on preventive behaviours to decrease transmission. However, malaria related behaviour change is often dependent upon local knowledge, beliefs, and practices, especially in areas where malaria is viewed an embedded and unavoidable aspect of life. METHODS: This exploratory case study used semi-structured interviews conducted in Spanish between February and March of 2019 to examine the knowledge, attitudes, and practices related to malaria prevention among the Indigenous Maijuna people of Sucusari, Loreto, Peru. Participants who consented were also administered a rapid diagnostic test (RDT) upon the time of interview. RESULTS: A total of 33 community members were interviewed, and 31 were tested via malaria rapid diagnostic tests, with RDT filter paper subsequently tested using PCR. All test results were negative for malaria. Themes that emerged included: varying knowledge of methods to prevent malaria, reports of observed changes in malaria incidence over time, confusion surrounding malaria transmission, treatment-seeking as a common behaviour, the belief that medications are effective, and the acceptance of bed nets which were viewed as a lifestyle norm. CONCLUSION: These shared narratives should be used as a foundation for further studies and health interventions among communities in the Peruvian Amazon with limited access to health services where culturally resonant, community-based health programming is essential to improving health. Takeaways regarding confusion surrounding malaria transmission should also be considered.

Unravelling heterogeneous malaria transmission dynamics in the Peruvian Amazon: insights from a cross-sectional survey.

BACKGROUND: Malaria remains a global health challenge, particularly in Peru's Loreto region. Despite ongoing efforts, high infection rates and asymptomatic cases perpetuate transmission. The Peruvian Ministry of Health's "Zero Malaria Plan" targets elimination. This novel study combines microscopic, molecular, and serological techniques to assess transmission intensity, identify epidemiological risk factors, and characterize species-specific patterns across villages. The findings aim to inform targeted interventions and support broader malaria elimination efforts in line with the Zero Malaria Plan initiative. METHODS: A cross-sectional malaria survey was conducted in the Zungarococha community, comprising the villages Llanchama (LL), Ninarumi (NI), Puerto Almendra (PA), and Zungarococha (ZG), using microscopic, molecular, and serological techniques to evaluate malaria transmission intensity. Statistical analysis, including multivariate-adjusted analysis, seroprevalence curves, and spatial clustering analysis, were performed to assess malaria prevalence, exposure, and risk factors. RESULTS: The survey revealed a high prevalence of asymptomatic infections (6% by microscopy and 18% by PCR), indicating that molecular methods are more sensitive for detecting asymptomatic infections. Seroprevalence varied significantly between villages, reflecting the heterogeneous malaria transmission dynamics. Multivariate analysis identified age, village, and limited bed net use as significant risk factors for malaria infection and species-specific exposure. Seroprevalence curves demonstrated community-specific patterns, with Llanchama and Puerto Almendra showing the highest seroconversion rates for both Plasmodium species. CONCLUSIONS: The study highlights the diverse nature of malaria transmission in the Loreto region, particularly nothing the pronounced heterogeneity as transmission rates decline, especially in residual malaria scenarios. The use of molecular and serological techniques enhances the detection of current infections and past exposure, aiding in the identification of epidemiological risk factors. These findings underscore the importance of using molecular and serological tools to characterize malaria transmission patterns in low-endemic areas, which is crucial for planning and implementing targeted interventions and elimination strategies. This is particularly relevant for initiatives like the Zero Malaria Plan in the Peruvian Amazon.

The "Cycle" of HIV: Limits of Personal Responsibility in HIV Vulnerability Among Transgender Adolescents and Young Women in Lima, Peru.

Globally, transgender women (TW) face a high burden of the HIV epidemic. In Peru, HIV prevalence among TW rises at age 25, indicating a need to understand HIV vulnerability as adolescents reach adulthood. The life course of TW is often marked by abuse, discrimination and poverty fueled by transphobic stigma. Approaches to the HIV epidemic among TW and adolescents emphasize problem behaviors such as unprotected sex and substance. However, there has been a call for HIV research and interventions to understand and leverage community strengths. This qualitative study utilized a transgender-oriented, strength-based, intersectional and feminist approach to understand the strengths and protective health behaviors among 17 transgender adolescents and young women (TAYW) age 16-24 in Lima, Peru. Most participants re-located to Lima from the Amazon due to familial rejection, and engaged in obligatory sex work. TAYW demonstrated self-knowledge, motivation for education, efforts to secure employment, strong community networks, legal advocacy, avoiding problem substance use, HIV knowledge and condom use. However, strengths were impeded by multi-level barriers such as familial physical abuse, educational discrimination, and sexual assault which led to increased HIV vulnerability. We created a conceptual model of the "cycle" of HIV to describe the limits of personal responsibility within a vulnerable community denied access to family, education, employment and human rights. We recommend researchers, clinicians and public health workers follow the lead of TAYW at the frontlines of the HIV epidemic, and support beloved communities and enabling environments which may permit protective behaviors to mitigate HIV vulnerability.

RESUMEN: A nivel mundial, las mujeres transgénero (MT) enfrentan una alta carga de la epidemia del VIH. En Perú, la prevalencia del VIH entre las MT aumenta a los 25 años, lo que indica la necesidad de comprender la vulnerabilidad al VIH a medida que las adolescentes llegan a la edad adulta. El curso de vida de las MT suele estar marcado por el abuso, la discriminación y la pobreza por culpa del estigma transfóbico. Los enfoques sobre la epidemia del VIH entre las MT y los adolescentes enfatizan conductas problemáticas como el sexo sin protección o el uso de sustancias. Sin embargo, existe un llamado a realizar investigaciones e intervenciones sobre el VIH para comprender y aprovechar las fortalezas de la comunidad. Este estudio cualitativo utilizó un enfoque feminista, interseccional, basado en fortalezas y orientado a las personas transgénero para comprender las fortalezas y los comportamientos protectores de la salud entre 17 adolescentes y mujeres jóvenes transgénero de 16 a 24 años en Lima, Perú. La mayoría de las participantes migraron a Lima desde la Amazonía debido al rechazo familiar y se dedicaron al trabajo sexual obligatorio. Las adolescentes y mujeres jóvenes transgénero demostraron autoconocimiento, motivación para la educación, esfuerzos para conseguir empleo, redes comunitarias sólidas, defensa legal, evitar el uso problemático de sustancias, conocimiento sobre el VIH y uso de condones. Sin embargo, las fortalezas se vieron obstaculizadas por barreras de múltiples niveles, como el abuso físico familiar, la discriminación educativa y la agresión sexual, que llevaron a una mayor vulnerabilidad al VIH. Desarrollamos un modelo conceptual del "ciclo" del VIH para describir los límites de la responsabilidad personal dentro de una comunidad vulnerable a la que se le niega el acceso a la familia, la educación, el empleo y los derechos humanos. Recomendamos que los investigadores, médicos y trabajadores de la salud pública sigan el ejemplo de adolescentes y mujeres jóvenes transgénero en la primera línea de la epidemia del VIH y apoyen a comunidades queridas y entornos propicios que puedan permitir conductas protectoras para mitigar la vulnerabilidad al VIH.

Influence of Stigma on Engagement in HIV Care and Adherence to Antiretroviral Therapy in Specialized HIV Clinics Targeting Men Who Have Sex with Men and Transgender Women in Lima, Peru.

HIV stigma is a social determinant of health that can influence multiple health outcomes, including adherence to antiretroviral therapy (ART), engagement in HIV care, and viral suppression levels in people with HIV (PWH). In Peru, where the HIV epidemic is concentrated in men who have sex with men (MSM) and transgender women (TGW), stigma may play an important role in healthcare engagement. To understand the relationship between stigma and two outcome variables, ART adherence and engagement in HIV care in 400 MSM and TGW, we assessed factors from the Behavioral Model for Vulnerable Populations at two HIV clinics that tailor services for sexual and gender minorities. While some predisposing, need, and enabling resource factors were associated with optimal (≥ 90%) ART adherence or engagement in HIV care, none of the stigma subscales were correlated, suggesting that when LGBTQ-affirming care is provided to MSM/TGW, stigma may not influence HIV-related outcomes.

RESUMEN: El estigma hacia el VIH es un determinante social de la salud que puede influir en múltiples desenlaces, incluyendo la adherencia a la terapia antirretroviral (TAR), el compromiso con la atención del VIH y los niveles de supresión viral en personas viviendo con VIH (PVV). En el Perú, donde la epidemia del VIH se concentra en hombres que tienen sexo con hombres (HSH) y mujeres transgénero (MT), el estigma puede desempeñar un papel importante en el compromiso con la atención médica. Para comprender la relación entre el estigma y dos variables de resultado, la adherencia al TAR y el compromiso con la atención del VIH en 400 HSH y MT, evaluamos factores del Modelo de Comportamiento para Poblaciones Vulnerables en dos clínicas de VIH que adaptan sus servicios para minorías sexuales y de género. Si bien algunos factores predisponentes, de necesidad y de recursos habilitantes se asociaron con una adherencia óptima (≥ 90%) al TAR o al compromiso con la atención del VIH, ninguna de las sub-escalas de estigma estuvieron correlacionadas, sugiriendo que cuando se brinda atención que afirma a la comunidad LGBTQ a HSH/MT, el estigma puede no influir en los desenlaces relacionados con el VIH.

HIV Risk Behaviors and the Use of Geosocial Networking Dating Apps among Men Who have Sex with Men and Transgender Women in Lima, Peru: a Cross-Sectional Study.

Geosocial networking dating apps (GSN apps) are an increasingly widespread technology used by populations throughout the world to facilitate sexual encounters. Studies from a variety of settings suggest a possible association between GSN app use and HIV risk behaviors, including among sexual and gender minority populations such as men who have sex with men (MSM) and transgender women (TW). However, it remains unclear to what extent GSN apps play a causal role. We explored the relationship between GSN app use and sexual risk behaviors among MSM and TW in Lima, Peru by analyzing data from a multi-site cross-sectional survey assessing both general and partner-specific sexual behaviors. We performed bivariate analysis to estimate the association of GSN app use with different individual and partner-specific factors, then fit multivariable regression models adjusting for age and education. Among 741 total participants (698 MSM, 43 TW), 64% met at least one sex partner in the prior three months using a GSN app. GSN app users were significantly more likely to report engaging in HIV risk behaviors in general, including condomless receptive anal sex, group sex, transactional sex, and sex under the influence of alcohol or drugs. Having condomless anal sex with a given partner was not associated with meeting that partner via GSN app. These findings highlight GSN app users as a particularly vulnerable subpopulation among MSM and TW in Lima. GSN apps could provide a useful vehicle for targeted HIV prevention efforts for priority populations in Peru.

RESUMEN: Las aplicaciones de citas de redes geosociales (aplicaciones GSN) son una tecnología con creciente alcance en todo el mundo usadas para facilitar encuentros sexuales. Diferentes estudios sugieren una posible relación entre uso de aplicaciones GSN y comportamientos de riesgo para VIH entre hombres que tienen sexo con hombres (HSH) y mujeres transgénero (MT). No es claro hasta qué punto aplicaciones GSN tendrían un papel causal directo. Exploramos la relación entre uso de aplicaciones GSN y comportamientos sexuales de riesgo entre HSH y MT en Lima, Perú, analizando datos de una encuesta transversal que evaluó comportamientos sexuales en general y en parejas específicas. Realizamos análisis bivariable para estimar la asociación del uso de aplicaciones GSN con diferentes factores individuales y específicos de la pareja. También aplicamos modelos de regresión multivariables ajustados por edad y educación. Entre 741 participantes totales (698 HSH, 43 MT), 64% conoció al menos a una pareja sexual en los últimos tres meses mediante una aplicación GSN. Los usuarios de aplicaciones GSN fueron significativamente más propensos a reportar comportamientos de riesgo de VIH en general, incluyendo sexo anal receptivo sin condón, y sexo grupal, transaccional y bajo influencia de alcohol o drogas. Tener sexo anal sin condón con una pareja determinada no se asoció con conocer a esa pareja mediante aplicación GSN. Estos hallazgos muestran a usuarios de aplicaciones GSN como una subpoblación particularmente vulnerable entre HSH y MT en Lima. Aplicaciones GSN podrían ser útiles para iniciativas de prevención del VIH en poblaciones prioritarias en Perú.