Sex bias in infectious disease epidemiology: patterns and processes

One Health and sex and gender-related perspective in the ecosystem: Interactions among drivers involved in the risk of leptospirosis in Europe. A scoping review

Leptospirosis has a complex transmission, involving rodents and many species of domestic and wild animals. Carrier animals spread leptospires, contaminating soil and water, the main sources of human infection. The risk of infection is modulated by socio-economic factors, environment and host animals and has changed, historically linked to agriculture but now prevalent in recreational environments. Leptospirosis also reveal gender-specific exposure patterns that determine infection risks. Emphasizing the interconnectedness of humans, animals, and the environment, the One Health approach highlights the ecosystem dynamics through which leptospires interact with hosts and abiotic factors, ensuring their survival and transmission. We advocate for integrating gender considerations into the ecosystem dynamics of complex zoonoses, such as leptospirosis, through a One Health perspective. This approach, yet to be fully explored, may enhance our understanding of the infection and its modulating factors. A scoping review of the literature was conducted across Embase and Pubmed databases to collect information on sex and gender-specific drivers, sources of infections, environmental drivers, and related risks of leptospirosis. Quantitative data were extracted from the articles selected according to a list of criteria, and analyzed to discern sex and gender disparities and identify primary drivers of leptospirosis. We confirmed that the excess of male leptospirosis cases described in many parts of the world is also present in Europe. Furthermore, we identified environmental and sociocultural drivers and hypothesized their interactions between and within human, animal, and environmental sectors. These interactions modulate direct and indirect exposure to Leptospira, heightening infection risks across the ecosystem. Based on our findings, utilizing leptospirosis as a model, we advocate for integrating One Health and gender approaches in public health practices to better plan and implement more effective and timely intervention measures.

Use of an inertial sensor and a force platform to assess static balance in participants affected by multibacillary leprosy

INTRODUCTION

Leprosy is a chronic, slowly developing infectious disease that affects the peripheral nerves, specifically Schwann cells. Individuals with the multibacillary type exhibit a propensity for developing chronic pain and a decrease in sensitivity in the plantar region, which directly interferes with balance maintenance. The evaluation of static balance in this population is made through the measurement of the center of pressure (COP) oscillations. Therefore, there is a need to investigate the association between postural control and COP oscillations using a force platform and finding accelerations of the center of mass (COM) from inertial sensors for reliable and portable balance assessment in leprosy patients.

OBJECTIVE

To validate the application of inertial sensors for patients with leprosy by establishing a correlation with the outcomes obtained from a force platform.

METHODS

This is an observational study with a case-control design, in which 30 participants with leprosy and 30 healthy participants were recruited to evaluate static balance using an inertial sensor and a force platform. Participants underwent balance assessment under two conditions (Eyes Open: OE and Eyes Closed: CE), and data from the platform and sensor were processed using Matlab computational routines. The data were quantified using four parameters: Total Displacement (TD), Area, Antero-Posterior Displacement (APdisp), and Medio-Lateral Displacement (MLdisp).

RESULTS

The evaluated parameters showed significantly different values between the groups, where the Leprosy group exhibited significantly higher values compared to the control group, both in the OE and CE conditions for all four parameters. The sensor corroborated the differences demonstrated by the platform and followed the same trend for medio-lateral displacements and accelerations. It can be observed that the evaluated parameters exhibited a varied correlation ranging from moderate to large between the platform and the sensor. Among the four variables, MLdisp had the lowest correlation.

DISCUSSION

The results partially confirmed the first hypothesis of concurrent validation, showing a moderate to large correlation between the force platform and the inertial sensor. The second hypothesis of clinical validation was also partially confirmed, as not all group differences observed in the COP measurements from the force platform were reflected in the COM measurements from the inertial sensor. Specifically, the force platform indicated greater oscillations in participants with multibacillary leprosy compared to controls, a finding statistically confirmed by the sensor for all measures except MLdisp.

CONCLUSION

This research confirmed the concurrent validity of the inertial sensor with the force platform and its clinical validation, demonstrating that this instrument can be applied in clinical settings due to its low cost and ease of use. The findings may contribute to public health by identifying postural control tools for patients with multibacillary leprosy.

Spatiotemporal distribution and risk factors for patient and diagnostic delays among groups with tuberculous pleurisy: an analysis of 5-year surveillance data in eastern China

Objective

To understand and analyze the factors relating to patient and diagnostic delays among groups with tuberculous pleurisy (TP), and its spatiotemporal distribution in Zhejiang Province.

Methods

Data of all tuberculous pleurisy patients were collected from the existing Tuberculosis Information Management System. A time interval of > 2 weeks between first symptom onset and visit to the designated hospital was considered a patient delay, and a time interval of > 2 weeks between the first visit and a confirmed TP diagnosis was considered a diagnostic delay. Univariate and multivariate logistic regression analyses were used to explore factors influencing patient and diagnostic delays in patients with TP. Spatial autocorrelation and spatiotemporal scan analyses were used to identify hot spots and risk clusters, respectively.

Results

In total, 10,044 patients with TP were included. The median time and interquartile range for patients seeking medical care and diagnosis were 15 (7-30) and 1 (0-8) days, respectively. The results showed that people aged > 65 years, retirees, and residents of Jinhua, Lishui, and Quzhou were positively correlated with patient delay, whereas retreatment patients, houseworkers, unemployed people, and residents of Zhoushan or Ningbo were positively correlated with diagnostic delay. Additionally, high-risk clusters of patient delays were observed in the midwestern Zhejiang Province. The most likely clusters of TP diagnostic delays were found in southeast Zhejiang Province.

Conclusion

In summary, patient delay of TP in Zhejiang province was shorter than for pulmonary tuberculosis in China, while the diagnostic delay had no difference. Age, city, occupation, and treatment history were related to both patient and diagnostic delays in TP. Interventions in central and western regions of Zhejiang Province should be initiated to improve the early detection of TP. Additionally, the allocation of health resources and accessibility of health services should be improved in the central and eastern regions of Zhejiang Province.

Androgens contribute to sex bias of autoimmunity in mice by T cell-intrinsic regulation of Ptpn22 phosphatase expression

Autoimmune diseases such as systemic lupus erythematosus (SLE) display a strong female bias. Although sex hormones have been associated with protecting males from autoimmunity, the molecular mechanisms are incompletely understood. Here we report that androgen receptor (AR) expressed in T cells regulates genes involved in T cell activation directly, or indirectly via controlling other transcription factors. T cell-specific deletion of AR in mice leads to T cell activation and enhanced autoimmunity in male mice. Mechanistically, Ptpn22, a phosphatase and negative regulator of T cell receptor signaling, is downregulated in AR-deficient T cells. Moreover, a conserved androgen-response element is found in the regulatory region of Ptpn22 gene, and the mutation of this transcription element in non-obese diabetic mice increases the incidence of spontaneous and inducible diabetes in male mice. Lastly, Ptpn22 deficiency increases the disease severity of male mice in a mouse model of SLE. Our results thus implicate AR-regulated genes such as PTPN22 as potential therapeutic targets for autoimmune diseases.

Gender differences in the associations of psychosocial trauma and acute medical stressors with immune system activation and dementia risk

Objective: The purpose of this article is to provide a narrative review synthesizing the literature on differences between women and men in relationships among certain stressors associated with immune system activation and their relationship to cognitive dysfunction and dementia. Method: We review the cycle of stress leading to neuroinflammation via cortisol and neurochemical alterations, cell-mediated immune system activation, and pro-inflammatory cytokines, and how this is implicated in the development of dementia. We follow this by discussing sex differences in stress physiology and immune function. We then review the work on early life adversity (ELA) and adverse childhood experiences (ACEs), post-traumatic stress disorder, acute medical stressors, and their associations with cognitive dysfunction and dementia. Throughout, we emphasize women's presentations and issues unique to women (e.g. trauma disorder prevalence). Conclusions: There is a need for more mechanistic and longitudinal studies that consider trauma accumulation, both physical and emotional, as well as a greater focus on traumas more likely to occur in women (e.g. sexual abuse), and their relationship to early cognitive decline and dementia.

Spatial-temporal distribution of visceral leishmaniasis in Rio de Janeiro, Brazil, 2001-2020: expansion and challenges

BACKGROUND

Visceral leishmaniasis results from complex interactions among humans, dogs and environment. Brazil accounts for 97% of cases in the Americas.

METHODS

Twenty years (2001-2020) of the endemic disease in the state of Rio de Janeiro were studied. Incidence, lethality, sociodemographic and clinical characteristics were investigated, complemented with spatial methodologies (kernel and clusters).

RESULTS

Ninety-seven human cases and 625 dogs were reported. Of the 92 cities, 22 were human endemic areas. The state had a low incidence level (0.6 per 100 000). Lethality was higher compared with the Brazilian average. More than 90% of infections occurred in urban areas. Most cases (66%) occurred in men. The predominant age groups were 0-4 y (28.7%) and 20-39 y (32.9%). Fever (89.5%), splenomegaly (83.2%) and hepatomegaly (76.8%) were the main clinical manifestations. Spatial analysis showed a displacement of the human endemic: in the first decade (2001-2010), cases were concentrated in the Metropolitan region, and in the second decade (2011-2020) in the Médio Paraíba region of the state. Most of the endemic area (56.4%) had canine infections without reported human cases.

CONCLUSIONS

Disorderly urbanisation and precarious living conditions favour the transmission of the disease. Changes in the environment and migratory processes contribute to its expansion.

Construction of an early differentiation diagnosis model for patients with severe fever with thrombocytopenia syndrome and hemorrhagic fever with renal syndrome

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with a high mortality rate. Differentiating between SFTS and hemorrhagic fever with renal syndrome (HFRS) is difficult and inefficient. Retrospective analysis of the medical records of individuals with SFTS and HFRS was performed. Clinical and laboratory data were compared, and a diagnostic model was developed based on multivariate logistic regression analyzes. Receiver operating characteristic curve analysis was used to evaluate the diagnostic model. Among the 189 patients, 113 with SFTS and 76 with HFRS were enrolled. Univariate analysis revealed that more than 20 variables were significantly associated with SFTS. Multivariate logistic regression analysis revealed that gender, especially female gender (odds ratio [OR]: 4.299; 95% confidence interval [CI]: 1.163-15.887; p = 0.029), age ≥65 years (OR: 16.386; 95% CI: 3.043-88.245; p = 0.001), neurological symptoms (OR: 12.312; 95% CI: 1.638-92.530; p = 0.015), leukopenia (<4.0 × 109/L) (OR: 17.355; 95% CI: 3.920-76.839; p < 0.001), and normal Cr (OR: 97.678; 95% CI: 15.483-616.226; p < 0.001) were significantly associated with SFTS but not with HFRS. The area under the curve of the differential diagnostic model was 0.960 (95% CI: 0.936-0.984), which was significantly better than that of each single factor. In addition, the model exhibited very excellent sensitivity and specificity (92.9% and 85.5%, respectively). In cases where HFRS and SFTS are endemic, a diagnostic model based on five parameters, such as gender, age ≥65 years, neurological symptoms, leukopenia and normal Cr, will facilitate the differential diagnosis of SFTS and HFRS in medical institutions, especially in primary care settings.

Influence of environmental factors on the occurrence of gastrointestinal and cardiopulmonary nematodes in the red fox in the semi-arid Mediterranean areas of the Iberian Peninsula

Human-induced ecosystem fragmentation is one of the drivers causing wildlife migration from their natural habitats to urban areas, among other reasons. The red fox (Vulpes vulpes) is the most abundant wild canid in the semi-arid Mediterranean areas of the Iberian Peninsula. Water scarcity may result in areas shared by synanthropic fox populations and domestic animals becoming hotspots for parasite transmission. This study describes the gastrointestinal and cardiopulmonary nematode species affecting fox populations in these semi-arid areas and the influence of environmental variables on parasite abundance. A total of 167 foxes collected from 2015 to 2021 in the Region of Murcia (SE Spain) were analysed. Parasite abundance and spatial distribution were evaluated using environmental variables and host characteristics with a Generalised Linear Model and the Moran index. Eleven species (seven from the gastrointestinal tract and four from the cardiopulmonary tract) were described. The influence of biotic and abiotic variables was studied for Angiostrongylus vasorum, Crenosoma vulpis, Uncinaria stenocephala, Toxocara canis and Toxascaris leonina. Temperature, humidity and areas of forest or agricultural land influenced the abundance of these parasites, providing optimal conditions for free-living stages of the direct life cycle nematodes and intermediate hosts. Absolute abundance distribution maps showed defined locations for C. vulpis, T. canis and T. leonina. The results for U. stenocephala, T. canis and T. leonina were particularly important as their higher abundance levels were found close to anthropized areas, which need to be carefully evaluated to prevent transmission of these nematodes between domestic and wild canids and human health.

Assessing intersectional gender analysis in Nepal's health management information system: a case study on tuberculosis for inclusive health systems

BACKGROUND

Tuberculosis (TB) remains a major public health problem in Nepal, high in settings marked by prevalent gender and social inequities. Various social stratifiers intersect, either privileging or oppressing individuals based on their characteristics and contexts, thereby increasing risks, vulnerabilities and marganilisation associated with TB. This study aimed to assess the inclusiveness of gender and other social stratifiers in key health related national policies and the Health Management Information System (HMIS) of National Tuberculosis Programme (NTP) by conducting an intersectional analysis of TB cases recorded via HMIS.

METHODS

A desk review of key policies and the NTP's HMIS was conducted. Retrospective intersectional analysis utilized two secondary data sources: annual NTP report (2017-2021) and records of 628 TB cases via HMIS 6.5 from two TB centres (2017/18-2018/19). Chi-square test and multi-variate analysis was used to assess the association between social stratifers and types of TB, registration category and treatment outcome.

RESULTS

Gender, social inclusion and concept of intersectionality are incorporated into various health policies and strategies but lack effective implementation. NTP has initiated the collection of age, sex, ethnicity and location data since 2014/15 through the HMIS. However, only age and sex disaggregated data are routinely reported, leaving recorded social stratifiers of TB patients static without analysis and dissemination. Furthermore, findings from the intersectional analysis using TB secondary data, showed that male more than 25 years exhibited higher odds [adjusted odds ratio (aOR) = 4.95, 95% confidence interval (CI): 1.60-19.06, P = 0.01)] of successful outcome compared to male TB patients less than 25 years. Similarly, sex was significantly associated with types of TB (P < 0.05) whereas both age (P < 0.05) and sex (P < 0.05) were significantly associated with patient registration category (old/new cases).

CONCLUSIONS

The results highlight inadequacy in the availability of social stratifiers in the routine HMIS. This limitation hampers the NTP's ability to conduct intersectional analyses, crucial for unveiling the roles of other social determinants of TB. Such limitation underscores the need for more disaggregated data in routine NTP to better inform policies and plans contributing to the development of a more responsive and equitable TB programme and effectively addressing disparities.

Influence of female sex hormones on proactive behavioral and physiological immune parameters

Women may be more susceptible to infections in the luteal phase, supposedly as a consequence of the hormone progesterone and its immunosuppressive action. While immunosuppression may be important for successful oocyte implantation and pregnancy, it makes women more vulnerable to pathogens. According to theory, to compensate for reduced immunocompetence, women in the luteal phase exhibit proactive behavioral responses, such as disgust and avoidance of disease-associated stimuli, to minimize contagion risk. However, previous studies yielded inconsistent results, and did not account for accompanying proactive immune responses, like the increase of secretory immunoglobin A (sIgA). Here, we assessed the proactive immune response and feelings of disgust associated with disease cues in the comparison of 61 woman with a natural menstrual cycle (31 in the follicular and 30 in the luteal phase) and 20 women taking hormonal contraception (HC). Women rated disease vulnerability and disgust propensity, watched a video displaying people with respiratory symptoms, which was evaluated for its disgust-evoking potential and contagiousness, and provided saliva samples for hormone and sIgA analysis. Women with HC reported a heightened vulnerability to disease compared to naturally cycling women, whereas both the feeling of disgust and the sIgA increase elicited by the disease video were similar across groups, regardless of progesterone. We found a u-shaped relationship between progesterone and baseline sIgA in naturally cycling women, with its nadir during ovulation. Overall, our data do not support a compensatory relationship between the proposed progesterone-induced immunosuppression and heightened disgust or a proactive sIgA response.

Spatio-Temporal Analysis and Clinical-Epidemiological Characterization of Visceral Leishmaniasis in Maranhão, Brazil, from 2009 to 2020

This study was carried out to identify the spatial distribution and characterize the clinical-epidemiological profile of Visceral Leishmaniasis (VL) in Maranhão state, Brazil, from 2009 to 2020. This descriptive ecological study collected sociodemographic and clinical data of VL cases from the Brazilian Notifiable Diseases Information System database. A spatial autocorrelation analysis (Moran statistics) was performed. From 2009 to 2020, 5699 cases of VL were reported, with incidence of 6.5 cases/100,000 and prevalence of 7.1 cases/100,000. The temporal analysis showed a significant growth in incidence from 2009 to 2018, followed by a significant decrease between 2019 and 2020. The Moran map shows hotspots of high values in the central-west and central-east regions, and hotspots of low values in the northern region of Maranhão. The profile of patients affected by VL comprises males (OR = 1.8; IC95% = 1.72-1.92), aged under 14 years, brown, and with incomplete elementary schooling. The main symptoms reported were fever, fatigue, and edema. The main diagnostic method was laboratory. The mortality rate was 6.8%, and co-infection with HIV was reported by 8.5% of patients. The results of this study indicated the increase in incidence and lethality, as well as the expansion, of leishmaniasis in the state of Maranhão.

Sex differences in CD8+ T cell responses during adaptive immunity

Biological sex is an important variable that influences the immune system's susceptibility to infectious and non-infectious diseases and their outcomes. Sex dimorphic features in innate and adaptive immune cells and their activities may help to explain sex differences in immune responses. T lymphocytes in the adaptive immune system are essential to providing protection against infectious and chronic inflammatory diseases. In this review, T cell responses are discussed with focus on the current knowledge of biological sex differences in CD8+ T cell mediated adaptive immune responses in infectious and chronic inflammatory diseases. Future directions aimed at investigating the molecular and cellular mechanisms underlying sex differences in diverse T cell responses will continue to underscore the significance of understanding sex differences in protective immunity at the cellular level, to induce appropriate T cell-based immune responses in infection, autoimmunity, and cancer. This article is categorized under: Immune System Diseases > Molecular and Cellular Physiology Infectious Diseases > Molecular and Cellular Physiology.

Sex-structured disease transmission model and control mechanisms for visceral leishmaniasis (VL)

BACKGROUND

Leishmaniasis are a group of diseases caused by more than 20 species of the protozoan that are transmitted through the bite of female sand fly. The disease is endemic to 98 countries of the world. It affects most commonly the poorest of the poor and mainly males. Several research has been conducted to propose disease control strategies. Effective medical care, vector control, environmental hygiene, and personal protection are the mainstays of the current preventative and control methods. The mathematical models for the transmission dynamics of the disease studied so far did not consider the sex-biased burden of the disease into consideration.

METHODOLOGY

Unlike the previous VL works, this study introduces a new deterministic sex-structured model for understanding the transmission dynamics of visceral leishmaniasis. Basic properties of the model including basic reproduction number ([Formula: see text]), and conditions for the existence of backward bifurcation of the model are explored. Baseline parameter values were estimated after the model was fitted to Ethiopia's VL data. Sensitivity analysis of the model was performed to identify the parameters that significantly impact the disease threshold. Numerical simulations were performed using baseline parameter values, and scenario analysis is performed by changing some of these parameters as appropriate.

CONCLUSION

The analysis of the model shows that there is a possibility for a backward bifurcation for [Formula: see text], which means bringing [Formula: see text] to less than unity may not be enough to eradicate the disease. Our numerical result shows that the implementation of disease-preventive strategies, as well as effectively treating the affected ones can significantly reduce the disease prevalence if applied for more proportion of the male population. Furthermore, the implementation of vector management strategies also can considerably reduce the total prevalence of the disease. However, it is demonstrated that putting more effort in treating affected reservoir animals may not have any significant effect on the overall prevalence of the disease as compared to other possible mechanisms. The numerical simulation infers that a maximum of 60% of extra preventative measures targeted to only male population considerably reduces the total prevalence of VL by 80%. It is also possible to decrease the total prevalence of VL by 69.51% when up to 50% additional infected males receive treatment with full efficacy. Moreover, applying a maximum of 15% additional effort to reduce the number of vectors, decreases the total VL prevalence by 57.71%. Therefore, in order to reduce the disease burden of visceral leishmaniasis, public health officials and concerned stakeholders need to give more emphasis to the proportion of male humans in their intervention strategies.

Immune cell composition varies by age, sex and exposure to social adversity in free-ranging Rhesus Macaques

Increasing age is associated with dysregulated immune function and increased inflammation-patterns that are also observed in individuals exposed to chronic social adversity. Yet we still know little about how social adversity impacts the immune system and how it might promote age-related diseases. Here, we investigated how immune cell diversity varied with age, sex and social adversity (operationalized as low social status) in free-ranging rhesus macaques. We found age-related signatures of immunosenescence, including lower proportions of CD20 + B cells, CD20 + /CD3 + ratio, and CD4 + /CD8 + T cell ratio - all signs of diminished antibody production. Age was associated with higher proportions of CD3 + /CD8 + Cytotoxic T cells, CD16 + /CD3- Natural Killer cells, CD3 + /CD4 + /CD25 + and CD3 + /CD8 + /CD25 + T cells, and CD14 + /CD16 + /HLA-DR + intermediate monocytes, and lower levels of CD14 + /CD16-/HLA-DR + classical monocytes, indicating greater amounts of inflammation and immune dysregulation. We also found a sex-dependent effect of exposure to social adversity (i.e., low social status). High-status males, relative to females, had higher CD20 + /CD3 + ratios and CD16 + /CD3 Natural Killer cell proportions, and lower proportions of CD8 + Cytotoxic T cells. Further, low-status females had higher proportions of cytotoxic T cells than high-status females, while the opposite was observed in males. High-status males had higher CD20 + /CD3 + ratios than low-status males. Together, our study identifies the strong age and sex-dependent effects of social adversity on immune cell proportions in a human-relevant primate model. Thus, these results provide novel insights into the combined effects of demography and social adversity on immunity and their potential contribution to age-related diseases in humans and other animals.

Sex-Specific Associations between Prenatal Exposure to Di(2-ethylhexyl) Phthalate, Epigenetic Age Acceleration, and Susceptibility to Early Childhood Upper Respiratory Infections

Di(2-ethylhexyl) phthalate (DEHP) is a common plasticizer that can affect immune system development and susceptibility to infection. Aging processes (measured as epigenetic age acceleration (EAA)) may mediate the immune-related effects of prenatal exposure to DEHP. This study's objective was to examine associations between prenatal DEHP exposure, EAA at three months of age, and the number of upper respiratory infections (URIs) from 12 to 18 months of age using a sample of 69 maternal-child pairs from a Canadian pregnancy cohort. Blood DNA methylation data were generated using the Infinium HumanMethylation450 BeadChip; EAA was estimated using Horvath's pan-tissue clock. Robust regressions examined overall and sex-specific associations. Higher prenatal DEHP exposure (B = 6.52, 95% CI = 1.22, 11.81) and increased EAA (B = 2.98, 95% CI = 1.64, 4.32) independently predicted more URIs. In sex-specific analyses, some similar effects were noted for boys, and EAA mediated the association between prenatal DEHP exposure and URIs. In girls, higher prenatal DEHP exposure was associated with decreased EAA, and no mediation was noted. Higher prenatal DEHP exposure may be associated with increased susceptibility to early childhood URIs, particularly in boys, and aging biomarkers such as EAA may be a biological mechanism. Larger cohort studies examining the potential developmental immunotoxicity of phthalates are needed.

Mosquito Salivary Antigens and Their Relationship to Dengue and P. vivax Malaria

In tropical areas, the simultaneous transmission of multiple vector-borne diseases is common due to ecological factors shared by arthropod vectors. Malaria and dengue virus, transmitted by Anopheles and Aedes mosquitoes, respectively, are among the top vector-borne diseases that cause significant morbidity and mortality in endemic areas. Notably, tropical areas often have suitable conditions for the co-existence of these mosquito species, highlighting the importance of identifying markers that accurately indicate the risk of acquiring each specific disease entity. Aedes are daytime-biting mosquitoes, while Anopheles preferentially bite during the night. These biting patterns raise the possibility of concurrent exposure to bites from both species. This is important because mosquito saliva, deposited in the skin during blood feeding, induces immune responses that modulate pathogen establishment and infection. Previous studies have focused on characterizing such effects on the vector-pathogen interface for an individual pathogen and its mosquito vector. In this study, we evaluated associations between immune responses to salivary proteins from non-dengue and non-malaria vector mosquito species with clinical characteristics of malaria and dengue, respectively. Surprisingly, antibody responses against Anopheles antigens in dengue patients correlated with red blood cell count and hematocrit, while antibody responses against Aedes proteins were associated with platelet count in malaria patients. Our data indicate that concurrent exposure to multiple disease-carrying mosquito vectors and their salivary proteins with differing immunomodulatory properties could influence the transmission, pathogenesis, and clinical presentation of malaria, dengue fever, and other vector-borne illnesses.

Individual heterogeneity in ixodid tick infestation and prevalence of Borrelia burgdorferi sensu lato in a northern community of small mammalian hosts

Heterogeneous aggregation of parasites between individual hosts is common and regarded as an important factor in understanding transmission dynamics of vector-borne diseases. Lyme disease is vectored by generalist tick species, yet we have a limited understanding of how individual heterogeneities within small mammal host populations affect the aggregation of ticks and likelihood of infection. Male hosts often have higher parasite and infection levels than females, but whether this is linked to sexual body size dimorphism remains uncertain. Here, we analysed how host species, sex, and body mass influenced Ixodes ricinus tick infestations and the infection prevalence of Borrelia burgdorferi sensu lato (s.l.) in three species of small mammals involved in the enzootic transmission cycle of Lyme disease in Norway from 2018 to 2022. Larval and nymphal ticks were found on 98% and 34% of all individual hosts, respectively. In bank voles and wood mice, both larval and nymphal tick infestation and infection probability increased with body mass, and it increased more with mass for males than for females. Tick infestation in the common shrew increased with body mass and was higher in males, while pathogen infection was higher in females. Sex-biases in infestation did not correspond with level of sexual body mass dimorphism across species. This study contributes to our understanding of how individual heterogeneity among small mammalian hosts influences I. ricinus tick aggregation and prevalence of B. burgdorferi s.l. at northern latitudes.

One Health Approach to Leptospirosis: Dogs as Environmental Sentinels for Identification and Monitoring of Human Risk Areas in Southern Brazil

Leptospirosis has been a neglected, widespread and reemerging zoonotic disease of global importance. The One Health holistic approach combining human, animal and environmental health has been important for control and prevention of zoonotic disease. An urban municipality in Southern Brazil with a high prevalence of leptospirosis was selected by convenience, with asymptomatic human and canine individuals serologically tested using MAT against 30 Leptospira spp. serovars. Epidemiological questionnaires were assessed along with the historical national database, with associated risk factors to dog and human seropositivity analyzed using multiple logistic regression. The spatial distribution of retrospective human leptospirosis cases was analyzed using a Kernel map and overlapped dog seropositivity and historical flooding areas, demonstrating that domestic and asymptomatic dogs may be important environmental sentinels for leptospirosis in such urban areas, even in the absence of human seropositivity and low canine seropositivity. Associated risk factors for leptospirosis in dogs and humans according to multiple regression included healthy dogs (p = 0.02, odds ratio-OR = 0.17, confidence interval of 95%CI 0.03-0.71) with indoor access (p = 0.059, OR = 5.12, 95%CI 1.10-37.7) and human males (p = 0.042, OR = 2.44, 95%CI 1.08-6.11) with presenting calf pain (p = 0.005, OR = 3.14, 95%CI 1.46-7. 14), jaundice (p < 0.001, OR = 4.61, 95%CI 2.11-10.10) and renal failure (p = 0.008, OR = 4.49, 95%CI 1.49-13.76). The greater the rain precipitation (above 3 mm of average annual precipitation), the higher the number of leptospirosis cases in humans. In conclusion, dog active serosurvey and rain precipitation should be systematically reported and plotted altogether as a basis for the early detection and monitoring of human risk areas. Such findings may serve as a basis for public health policies in Brazil and other endemic countries worldwide.

Assessment of gender differences in some inflammatory cytokines of tuberculosis patients before and during treatment

Background

Gender variation is a feature of many physiological parameters including inflammatory cytokines. Inflammation is an obvious feature of Tuberculosis (TB) infection with changes in pro and anti-inflammatory cytokines.

Objective

To compare the levels of inflammatory cytokines between male and female TB patients before treatment, after 2-months and after 6-months anti-tuberculosis treatment.

Materials and methods

A total of 35 males and 25 females TB subjects were enlisted before initiation of therapy and followed up after 2-months and 6 months treatment and samples collected and analysed. Tumour necrosis factor-alpha (TNF-α), Interleukin 10 (IL-10, Interleukin -6 (IL-6), Interleukin-2 (IL-2), transforming growth factor-beta (TGF-β) were assayed by ELISA method.

Results

Before treatment, the median level of IL-6 (pg/ml) was significantly higher in males compared to female TB patients (P=0.046). While after 2-months treatment, TNF-α (pg/ml) and IL-10 (pg/ml) was significantly higher in males compared with females (P=0.008 and 0.045 respectively). Conversely, the median IL-6 (pg/ml) was significantly higher in female TB patients compared to the males (P=0.042). No significant differences were observed after 6-months treatment.

Conclusion

Gender differences exist in IL-6 before treatment and in IL-6, TNF-α and IL-10 at two months treatment. Thus, TB treatment contributes differentially to levels of inflammatory cytokines in male and female TB patients.

Systematic Review of Treatment Failure and Clinical Relapses in Leishmaniasis from a Multifactorial Perspective: Clinical Aspects, Factors Associated with the Parasite and Host

Leishmaniasis is a disease caused by protozoa of the genus Leishmania. Treatment options are limited, and there are frequent cases of treatment failure and clinical relapse. To understand these phenomena better, a systematic review was conducted, considering studies published between 1990 and 2021 in Portuguese, English, and Spanish. The review included 64 articles divided into three categories. Case reports (26 articles) focused on treatment failure and clinical relapse in cutaneous leishmaniasis patients (47.6%), primarily affecting males (74%) and children (67%), regardless of the clinical manifestation. Experimental studies on the parasite (19 articles), particularly with L. major (25%), indicated that alterations in DNA and genic expression (44.82%) played a significant role in treatment failure and clinical relapse. Population data on the human host (19 articles) identified immunological characteristics as the most associated factor (36%) with treatment failure and clinical relapse. Each clinical manifestation of the disease presented specificities in these phenomena, suggesting a multifactorial nature. Additionally, the parasites were found to adapt to the drugs used in treatment. In summary, the systematic review revealed that treatment failure and clinical relapse in leishmaniasis are complex processes influenced by various factors, including host immunology and parasite adaptation.

Visceral Leishmaniasis Associated with HIV Coinfection in Pará, Brazil

Introduction

Human visceral leishmaniasis (VL) is a zoonosis of great importance to public health due to its epidemiological diversity, with emphasis on the possibility of aggravation by coinfection with the human immunodeficiency virus (HIV).

Objective

The aim was to study the epidemiological characteristics of VL cases associated with HIV coinfection in Pará. Methods. Reported cases of VL from January 2006 to December 2016 were investigated. A descriptive epidemiological method related to age, gender, area of residence and coinfection with HIV was used. To calculate variance and test equity, the F-test (Fisher) was performed. To observe the influence of one aspect on another, the chi-square was used to verify if there was dependence or independence between the variables.

Results

A total of 1171 cases of VL were reported during the study period. There was an annual mean of LV of 94.9, with a statistical difference (p<0.05) between age groups, with the highest number of cases being observed in children aged 1 to 4 years (27.16%). Males and the urban area had a higher number of cases. There were 57 cases of VL/HIV coinfection, with emphasis on the year 2013 and the municipality of Santarém, which had the highest number of cases. During the ten years studied, there was a correlation between coinfection VL/ HIV, with significant differences between patients with and without HIV who contracted VL (p<0.001).

Conclusion

The data reveal the endemic nature of VL in the region, with a high percentage of infection in children living in urban areas. Although the studied region is not identified as a predominant area of HIV cases, this study showed a high annual average (10.3) of cases of VL/HIV coinfection being the first time that cases of VL/HIV coinfection were reported in the Mesoregion of the Lower Amazon and Southwest Pará.

Sex-biased immunological processes drive hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that can manifest with abscesses, sinus tracts, and scarring in the intertriginous areas of the body. HS is characterized by immune dysregulation, featuring elevated levels of myeloid cells, T helper (Th) cells, and pro-inflammatory cytokines, particularly those involved in Th1- and Th17-mediated immunity. In most epidemiological studies, HS shows a strong female sex bias, with reported female-to-male ratios estimated at roughly 3:1, suggesting that sex-related factors contribute to HS pathophysiology. In this article, we review the role of intrinsic and extrinsic factors that contribute to immunological differences between the sexes and postulate their role in the female sex bias observed in HS. We discuss the effects of hormones, X chromosome dosage, genetics, the microbiome, and smoking on sex-related differences in immunity to postulate potential immunological mechanisms in HS pathophysiology. Future studies are required to better characterize sex-biased factors that contribute to HS disease presentations.

Sex Differences in TB Clinical Presentation, Drug Exposure, and Treatment Outcomes in India

BACKGROUND

The role of sex differences in clinical presentation, TB drug pharmacokinetic variables, and treatment outcomes is unclear.

RESEARCH QUESTION

What is the effect of sex on TB disease severity, drug exposure, and treatment outcome?

STUDY DESIGN AND METHODS

This study was a prospective cohort study conducted in India. It assessed TB disease severity; risk of unfavorable treatment outcomes (failure, recurrence, and death) according to sex; and risk factors for unfavorable outcomes stratified according to sex. Effects of sex on the pharmacokinetic variables (maximum concentration and area under the curve) of rifampicin, isoniazid, and pyrazinamide were estimated by using noncompartmental analyses.

RESULTS

Of 1,541 people with microbiologically confirmed TB, 567 (37%) were women. Women had a lower risk of high mycobacterial burden (smear grade ≥ 2 and/or time to detection < 7 days) with an adjusted OR of 0.70 (95% CI, 0.56-0.87). Among the 744 participants who were followed up prospectively, 261 (35%) were women. Women had a lower risk of unfavorable treatment outcomes (adjusted incidence risk ratio, 0.60; 95% CI, 0.43-0.85), mostly because recurrence was lower (adjusted incidence risk ratio, 0.45; 95% CI, 0.23-0.86). Isoniazid (but not rifampicin and pyrazinamide) maximum concentration and area under the curve were significantly higher among women (P < .01) than men. Among women, unfavorable outcomes were more likely among those with cavitary disease, but among men, increased risk of unfavorable outcomes was associated with alcohol use, higher BMI, and lower glycated hemoglobin level.

INTERPRETATION

Women present with lower mycobacterial burden, achieve higher TB drug exposure, and are less likely to have unfavorable treatment outcomes than men. Strategies to improve TB treatment success should take into account sex differences in risk factors for unfavorable outcomes.

The influence of the host sex on parasitemia of parasite lineages belonging to Haemoproteus majoris in a natural bird community

Immunological capability shows a sexual dimorphism in diverse animal species. Females are generally more immunocompetent than males, leading to the higher susceptibility of males to infection compared to females and thus greater infection-related pathology in males. These sex-differences in immunity remain understudied in birds. Here, we compared the percentage of parasitemia of three different parasite lineages belonging to the morphological species Haemoproteus majoris (namely, PARUS1, PHSIB1 and WW2) in terms of the sex of birds living in a natural community. We found that parasitemia (percentage of erythrocytes infected with parasites) of WW2 lineage, but not of the other two lineages of H. majoris, is higher in male birds compared to female birds. Similarly, we showed that the total parasitemia of these three H. majoris lineages is higher in male birds compared to female birds. Our study points out that male birds at the community level may be more susceptible to infection by certain parasites than female birds. We propose that sexual dimorphism in parasitemia of certain parasites in host birds might be more common than previously thought, similar to what is observed in other species, influencing host population dynamics in a sex-specific manner. Therefore, it can be speculated that infection by certain parasites might differentially affect male and female birds, possibly resulting in a bias in survival rates between sexes due to infections, in certain contexts.

Sex-biased infections scale to population impacts for an emerging wildlife disease

Demographic factors are fundamental in shaping infectious disease dynamics. Aspects of populations that create structure, like age and sex, can affect patterns of transmission, infection intensity and population outcomes. However, studies rarely link these processes from individual to population-scale effects. Moreover, the mechanisms underlying demographic differences in disease are frequently unclear. Here, we explore sex-biased infections for a multi-host fungal disease of bats, white-nose syndrome, and link disease-associated mortality between sexes, the distortion of sex ratios and the potential mechanisms underlying sex differences in infection. We collected data on host traits, infection intensity and survival of five bat species at 42 sites across seven years. We found females were more infected than males for all five species. Females also had lower apparent survival over winter and accounted for a smaller proportion of populations over time. Notably, female-biased infections were evident by early hibernation and likely driven by sex-based differences in autumn mating behaviour. Male bats were more active during autumn which likely reduced replication of the cool-growing fungus. Higher disease impacts in female bats may have cascading effects on bat populations beyond the hibernation season by limiting recruitment and increasing the risk of Allee effects.

Sex differences in neuroimmunoendocrine communication. Involvement on longevity

Endocrine, nervous, and immune systems work coordinately to maintain the global homeostasis of the organism. They show sex differences in their functions that, in turn, contribute to sex differences beyond reproductive function. Females display a better control of the energetic metabolism and improved neuroprotection and have more antioxidant defenses and a better inflammatory status than males, which is associated with a more robust immune response than that of males. These differences are present from the early stages of life, being more relevant in adulthood and influencing the aging trajectory in each sex and may contribute to the different life lifespan between sexes.

Forty years (1980-2019) of visceral leishmaniasis in Nepal: trends and elimination challenges

BACKGROUND

Visceral leishmaniasis (VL) is an important re-emerging neglected tropical disease associated with poverty. Despite the elimination initiative started in 2005, VL cases have been expanding into geographic areas in Nepal. The present study aims at exploring the trends of VL from 1980 to 2019.

METHODS

This retrospective analysis covers 40 y of VL cases reported by the Epidemiology Diseases Control Division, Nepal. Subgroup analyses for annual incidence were performed by age, sex, seasons, districts and provinces, and VL cases were visualized on in-country maps.

RESULTS

A total of 34 564 cases and 584 deaths of VL were reported during 1980-2019. VL persistently increased until 2006 and was reported from all seven provinces of the country. The highest number of confirmed cases (n=2229) was reported in 2003 and the lowest (n=60) in 1983. VL cases expanded from 12 to 23 endemic districts. The key components of the VL elimination program are early diagnosis; enhanced surveillance; integrated vector management; social mobilization; research and treatment.

CONCLUSIONS

Expansion of VL towards the hilly and mountain regions of Nepal has posed challenges to the elimination program. Urgent VL control measures are required to achieve the elimination goals.

Transmission factors and exposure to infections at work and invasive pneumococcal disease

BACKGROUND

Working in close contacts with coworkers or the general public may be associated with transmission of invasive pneumococcal disease (IPD). We investigated whether crowded workplaces, sharing surfaces, and exposure to infections were factors associated with IPD.

METHODS

We studied 3,968 cases of IPD, and selected six controls for each case from the Swedish population registry with each control being assigned the index date of their corresponding case. We linked job histories to job-exposure matrices to assess different transmission dimensions of pneumococci, as well as occupational exposure to fumes. We used adjusted conditional logistic analyses to estimate the odds ratios (ORs) for IPD with 95% confidence intervals (95% CI).

RESULTS

ORs for IPD for the different transmission dimensions were increased moderately but were statistically significant. Compared to home-working or working alone, the highest odds was for Working mostly outside, or partly inside (OR 1.19, 95% CI 1.04-1.38). Estimates were higher in men for all dimensions, compared to women. The odds for IPD for Working mostly outside, or partly inside were 1.33 (95% CI 1.13-1.56) and 0.79 (95% CI 0.55-1.14) for men and women, respectively. Higher odds were seen for all transmission dimensions among those exposed to fumes, although CIs included unity. Contact with ill or infected patients did not increase the odds for IPD.

CONCLUSION

IPD was associated with working in close contact with coworkers or the general public, and with outside work, especially for men. Contact with infected patients or persons was not associated with IPD.

Identification of Hazard and Socio-Demographic Patterns of Dengue Infections in a Colombian Subtropical Region from 2015 to 2020: Cox Regression Models and Statistical Analysis

Dengue is a disease of high interest for public health in the affected localities. Dengue virus is transmitted by Aedes species and presents hyperendemic behaviors in tropical and subtropical regions. Colombia is one of the countries most affected by the dengue virus in the Americas. Its central-west region is a hot spot in dengue transmission, especially the Department of Antioquia, which has suffered from multiple dengue outbreaks in recent years (2015-2016 and 2019-2020). In this article, we perform a retrospective analysis of the confirmed dengue cases in Antioquia, discriminating by both subregions and dengue severity from 2015 to 2020. First, we conduct an exploratory analysis of the epidemic data, and then a statistical survival analysis is carried out using a Cox regression model. Our findings allow the identification of the hazard and socio-demographic patterns of dengue infections in the Colombian subtropical region of Antioquia from 2015 to 2020.

Jaguar’s Predation and Human Shield, a Tapir Story

Despite the risks associated, some species choose to shield behind a predator to decrease predation risk by another predator. In this study, we demonstrate how Baird’s tapirs (Tapirus bairdii) use humans as a “shield” to reduce the risk of being preyed upon by jaguars (Panthera onca). We collected georeferenced photographic records of 23 tapirs (seven of them injured) sighted near human settlements (0 to 5 km) in the Calakmul region of Mexico from 2008 to 2019. Using multidimensional scale analysis, we determined which possible factors (tapir health status, injuries, distance to the settlement, as well as seasonality) are related to the decision of tapirs to approach human settlements. To support our claims of jaguars’ attacks, we described the pattern of injuries believed to have been inflicted by jaguars on tapirs, and we analysed photographs and videos of species of the genus Panthera attacking larger prey than themselves to establish a pattern of injuries and compare it to the injuries observed on tapirs. Our study shows that tapir sightings near human settlements are related to health deterioration, injuries by jaguars and seasonality. The injuries found on tapirs are similar to those caused by other big cats on large prey, providing strong support for jaguar-inflicted wounds. Further studies should investigate whether the increasing human presence in different habitats in the Neotropical region could be influencing the behaviour and distribution of prey and predators.

Why is leptospirosis hard to avoid for the impoverished? Deconstructing leptospirosis transmission risk and the drivers of knowledge, attitudes, and practices in a disadvantaged community in Salvador, Brazil

Several studies have identified socioeconomic and environmental risk factors for infectious disease, but the relationship between these and knowledge, attitudes, and practices (KAP), and more importantly their web of effects on individual infection risk, have not previously been evaluated. We conducted a cross-sectional KAP survey in an urban disadvantaged community in Salvador, Brazil, leveraging on simultaneously collected fine-scale environmental and epidemiological data on leptospirosis transmission. Residents' knowledge influenced their attitudes which influenced their practices. However, different KAP variables were driven by different socioeconomic and environmental factors; and while improved KAP variables reduced risk, there were additional effects of socioeconomic and environmental factors on risk. For example, males and those of lower socioeconomic status were at greater risk, but once we controlled for KAP, male gender and lower socioeconomic status themselves were not direct drivers of seropositivity. Employment was linked to better knowledge and a less contaminated environment, and hence lower risk, but being employed was independently associated with a higher, not lower risk of leptospirosis transmission, suggesting travel to work as a high risk activity. Our results show how such complex webs of influence can be disentangled. They indicate that public health messaging and interventions should take into account this complexity and prioritize factors that limit exposure and support appropriate prevention practices.

Sex-biased expression of the TLR7 gene in severe COVID-19 patients: Insights from transcriptomics and epigenomics

There is abundant epidemiological data indicating that the incidence of severe cases of coronavirus disease (COVID-19) is significantly higher in males than females worldwide. Moreover, genetic variation at the X-chromosome linked TLR7 gene has been associated with COVID-19 severity. It has been suggested that the sex-biased incidence of COVID-19 might be related to the fact that TLR7 escapes X-chromosome inactivation during early embryogenesis in females, thus encoding a doble dose of its gene product compared to males. We analyzed TLR7 expression in two acute phase cohorts of COVID-19 patients that used two different technological platforms, one of them in a multi-tissue context including saliva, nasal, and blood samples, and a third cohort that included different post-infection timepoints of long-COVID-19 patients. We additionally explored methylation patterns of TLR7 using epigenomic data from an independent cohort of COVID-19 patients stratified by severity and sex. In line with genome-wide association studies, we provide supportive evidence indicating that TLR7 has altered CpG methylation patterns and it is consistently downregulated in males compared to females in the most severe cases of COVID-19.

Leprosy Epidemiology According to Leprosy Type in 13 Teaching Hospitals in Indonesia between 2018 and 2020

BACKGROUND: Leprosy or Hansen’s disease is an infectious disease caused by Mycobacterium leprae (M. leprae) bacilli which results in chronic infections in humans that affect the peripheral nerves, skin, and other organs such as the eyes, mucous membranes, bones, and testicles. Leprosy has a variety of clinical presentations, depending on the cell-mediated immunity of the host. Leprosy is classified by the World Health Organization (WHO) as paucibacillary type (PB) and multibacillary type (MB) depending on the number of lesions. This multicenter study aims to provide representation of leprosy types and its epidemiology in Indonesia. AIM: The purpose of this study is to find out the epidemiology according to the leprosy type in 13 teaching hospitals in Indonesia between 2018 and 2020. METHODS: This is a descriptive study with cross-sectional design. All patients with the diagnosis of PB or MB type of leprosy who underwent Multidrug Therapy (MDT) treatment between 2018 and 2020 were included in this study. Data collection was carried out by tracing medical records data in 13 teaching hospitals in Indonesia. RESULTS: A total of 2129 leprosy patients were included in this study. There were 232 cases (10.8%) of PB leprosy and 1897 cases (89.1%) of MB leprosy. The average age of the patients is 38.7 years (SD ± 16.2 years). Males are more affected by leprosy (n = 1,441; 67.7%) compared to female (n = 688; 32.3%). CONCLUSION: Leprosy remains as a national health problem. The increasing cases of MB leprosy in Indonesia are caused by several factors including the lack of knowledge about leprosy, the delay in diagnosis of leprosy, and the stigma of leprosy within the community; therefore, it becomes a challenge to eliminate leprosy in Indonesia.

Early diagnostic markers in predicting the severity of dengue disease

The aim of the present study was to determine whether the serum ferritin, the biomarker of an acute phase reactant and the gall bladder wall edema, an early indicator of capillary leakage can predict the severity of dengue fever. This study included 131 patients, who were between the age group of 18–80 years. The patients presented to our department with an acute illness, within the first four days of high temperature. The statistical analysis of this study was performed by using the Chi-square and independent Student’s t tests. The diagnostic markers are considered statistically significant, if the serum ferritin level is higher than 500 ng/ml and the gall bladder wall thickness is more than 3 mm. The present study observed that, 39 patients (89%) who had severe dengue (n = 44) revealed a significant gall bladder wall thickening, and this correlation was significant statistically (p < 0.000). It was also observed that, the ferritin levels have a highly significant positive correlation with the severity of dengue. The severe dengue patients had a mean ferritin level of 9125.34 μg/l, whereas the non-severe group had 4271 μg/l. This comparison was also statistically significant, as the p value was 0.003. We report that the serum ferritin levels have a highly significant positive correlation with the severity of dengue. The gall bladder wall edema during the third and fourth day of the illness was also associated with severe dengue. However, diffuse gall bladder wall thickening and high serum ferritin levels are also reported in various other conditions and their exact cause have to be determined by the correlation of associated clinical findings and imaging features.

Cryptococcal meningitis in people living with Human Immunodeficiency Virus in Nepal: Perspectives from resource limited setting

Early diagnosis of cryptococcal meningitis among people living with HIV (PLHIV) is crucial for its therapeutic success. The objective of this study was to diagnose cryptococcal meningitis in PLHIV cases using the available laboratory techniques for its confirmation in resource limited setting. This cross-sectional prospective study was conducted among 72 PLHIV with clinical suspicion of meningitis. Each cerebrospinal fluid (CSF) sample received at National Public Health Laboratory, Kathmandu was processed for India ink staining, cryptococcal antigen lateral flow assay and fungal culture following standard protocols. The laboratory confirmed cryptococcal meningitis cases were between 24 and 69 years of age (median age 39 years) with 87.5% (12/14) of cases being male. Cryptococcus was detected in 22.22% (16/72) by any of the three tests, 19.44% (14/72) by cryptococcal antigen lateral flow assay, 16.66% (12/72) by India ink staining and 8.33% (6/72) by culture. High percentage of cryptococcal meningitis among PLHIV warrants early microbiological diagnosis for better case management. Cryptococcal antigen detection immunoassay should be the priority test for laboratory diagnosis of cryptococcal meningitis in PLHIV. Alternatively, very simple and economic India ink staining of CSF specimens could be used in resource limited settings.

Premenopausal and postmenopausal women during the COVID-19 pandemic

The current global COVID-19 mortality rate is estimated to be around 3.4%; however, it is dependent on age, sex, and comorbidities. Epidemiological evidence shows gender disparities in COVID-19 severity and fatality, with non-menopausal females having milder severity and better outcomes than age-matched males. However, the difference vanishes when comparing postmenopausal women with age-matched men. It has been suggested that, to some extent, this is due to the protective role of female hormones, such as anti-Müllerian hormone and oestradiol (E2), in non-menopausal women. Oestrogens have been hypothesized to be crucial in modulating viral infection and the progression of the disease via an action on immune/inflammatory responses and angiotensin-converting enzyme type 2 expression. Hence, the most likely explanation is that, because the levels of oestrogen in females after menopause decrease, oestrogen no longer offers a beneficial effect as seen in younger females. The COVID-19 pandemic has highlighted the serious negative effects arising from the state of E2 deficiency. Therefore, hormone replacement therapy gains further support as the damaging effect of the decline in ovarian function affects many biological systems, and recently with the COVID-19 pandemic, oestrogen's vital role within the immune system has become quite clear. However, additional clinical investigations regarding hormone replacement therapy are urgently needed to further verify the protective and therapeutic effects of E2 on menopausal women with COVID-19.

Retrospective Analysis of Leishmaniasis in Sicily (Italy) from 2013 to 2021: One-Health Impact and Future Control Strategies

Leishmaniasis is an important vector-borne disease that represents a serious public health problem, including in Sicily (Italy), which is considered an endemic area. We collected canine, feline and human data from 2013 to 2021 in Sicily, while entomological surveys were conducted only in 2013 and 2021. Overall, 23,794/74,349 (34.4%) of dogs and 274/4774 (11.8%) of cats were positive in one or more diagnostic tests. A total of 467 cases of human Leishmaniasis were reported, with 71% showing cutaneous and 29% visceral involvement. The provinces with the largest number of patients were Agrigento (45.4%) and Palermo (37%). In 2013, Phlebotomus perfiliewi was the dominant sandfly species in Sicily (68.7%), followed by Phlebotomus perniciosus (17.2%) and Sergentomya minuta (14%). In 2021, Phlebotomusperfiliewi was confirmed as the most common species (61.6%), followed by Phlebotomusperniciosus (33.1%) and Sergentomyaminuta (4.7%). Of particular interest was the identification of Phlebotomus papatasi (0.41%) in Agrigento. Our retrospective study can inform health authorities for the development of appropriate screening, treatment and control strategies to reduce Leishmania incidence rate. This study examined the present state of Leishmaniasis control, surveillance, and prevention in Sicily, but also highlighted deficiencies that could be addressed through the application of One-Health principles.

Sex-biased adaptive immune regulation in cancer development and therapy

The cancer research field is finally starting to unravel the mystery behind why males have a higher incidence and mortality rate than females for nearly all cancer types of the non-reproductive systems. Here, we explain how sex - specifically sex chromosomes and sex hormones - drives differential adaptive immunity across immune-related disease states including cancer, and why males are consequently more predisposed to tumor development. We highlight emerging data on the roles of cell-intrinsic androgen receptors in driving CD8+ T cell dysfunction or exhaustion in the tumor microenvironment and summarize ongoing clinical efforts to determine the impact of androgen blockade on cancer immunotherapy. Finally, we outline a framework for future research in cancer biology and immuno-oncology, underscoring the importance of a holistic research approach to understanding the mechanisms of sex dimorphisms in cancer, so sex will be considered as an imperative factor for guiding treatment decisions in the future.

Sex Differences in Active Pulmonary Tuberculosis Outcomes in Mali, West Africa

Men and women often respond differently to infectious diseases and their treatments. Tuberculosis (TB) is a life-threatening communicable disease that affects more men than women globally. Whether male sex is an independent risk factor for unfavorable TB outcomes, however, has not been rigorously investigated in an African context, where individuals are likely exposed to different microbial and environmental factors. We analyzed data collected from a cohort study in Mali by focusing on newly diagnosed active pulmonary TB individuals who were treatment naive. We gathered baseline demographic, clinical, and microbiologic characteristics before treatment initiation and also at three time points during treatment. More males than females were affected with TB, as evidenced by a male-to-female ratio of 2.4:1. In addition, at baseline, males had a significantly higher bacterial count and shorter time to culture positivity as compared with females. Male sex was associated with lower smear negativity rate after 2 months of treatment also known as the intensive phase of treatment, but not at later time points. There was no relationship between patients' sex and mortality from any cause during treatment. This study suggests that sex-based differences in TB outcomes exist, with sex-specific effects on disease outcomes being more pronounced before treatment initiation and during the intensive phase of treatment rather than at later phases of treatment.

Gender and Cutaneous Leishmaniasis in Israel

Leishmaniasis is estimated to be more common in males than in females. Our purpose was to evaluate differences in preponderance in relation to sex and gender across cutaneous and mucocutaneous leishmaniasis in Israel. An observational study was performed, including cases of endemic CL (cutaneous leishmaniasis) in Israel, and imported MCL (mucocutaneous leishmaniasis). CL is a notifiable disease and is supposed to be reported to the Ministry of Health (MOH). The MOH database shows that males as more likely to be infected by leishmania, with an incidence of 5/100,000 in males vs. 3.5/100,000 in females. However, while conducting a demographic house-to-house survey in several locations in Israel where CL is highly endemic, among 608 people who were screened only 49% were males in Leishmania major (L. major) endemic regions and 41% were males in Leishmania tropica (L. tropica) endemic regions, while among 165 cases of imported New-World cutaneous leishmaniasis in Israeli travelers freturning from abroad, 142 (86%) were males. It may be postulated that there is no real gender difference in leishmanial infection, but, perhaps, infections are more commonly seen in men because of referral/reported bias, due to more risk-taking behaviors by men or, perhaps, men are less likely to strictly adhere to recommended preventive measures and thus increase their risk of contracting the disease.

Multiparametric analysis of host and parasite elements in new world tegumentary leishmaniasis

Tegumentary leishmaniasis is a tropical disease caused by protozoa of the genus Leishmania. Clinically, the disease presents a broad spectrum of symptoms, the mechanisms underlying the development of lesions remaining to be fully elucidated. In the present work, we performed a correlation and multiparametric analysis to evaluate how parasite- and host-related aspects associate with each other, and with the different clinical manifestations of tegumentary leishmaniasis. This cross-sectional study involved 75 individuals from endemic areas of Brazil, grouped according to their symptoms. Leishmania species were determined by DNA sequencing, and parasite load, antibody production, and cytokine profile were evaluated by kDNA qPCR, ELISA, and flow cytometry. Data were analyzed using the Chi-square test, principal component analysis, canonical discriminant analysis, and correlation analysis. Among the recruited patients, 23 (31%) were asymptomatic, 34 (45%) had primary cutaneous leishmaniasis, 10 (13%) presented recurrent cutaneous leishmaniasis, and eight (11%) had mucocutaneous leishmaniasis. Leishmania species identified included L. amazonensis, L. braziliensis, and L. guyanensis. Surprisingly, no Leishmania RNA virus infection was detected in any sample. In summary, our work showed that parasite load, antibody production, and cytokine levels alone are not determinants for tegumentary leishmaniasis symptoms. However, the correlation analysis allowed us to observe how these factors are correlated to each other within the groups, which revealed a unique network for each clinical manifestation. Our work reinforces the complexity of tegumentary leishmaniasis outcomes - which are associated with multiple host and parasite-related elements and provides a holistic model of the disease.

Pandemics, past and present: The role of biological anthropology in interdisciplinary pandemic studies

Biological anthropologists are ideally suited for the study of pandemics given their strengths in human biology, health, culture, and behavior, yet pandemics have historically not been a major focus of research. The COVID‐19 pandemic has reinforced the need to understand pandemic causes and unequal consequences at multiple levels. Insights from past pandemics can strengthen the knowledge base and inform the study of current and future pandemics through an anthropological lens. In this paper, we discuss the distinctive social and epidemiological features of pandemics, as well as the ways in which biological anthropologists have previously studied infectious diseases, epidemics, and pandemics. We then review interdisciplinary research on three pandemics–1918 influenza, 2009 influenza, and COVID‐19–focusing on persistent social inequalities in morbidity and mortality related to sex and gender; race, ethnicity, and Indigeneity; and pre‐existing health and disability. Following this review of the current state of pandemic research on these topics, we conclude with a discussion of ways biological anthropologists can contribute to this field moving forward. Biological anthropologists can add rich historical and cross‐cultural depth to the study of pandemics, provide insights into the biosocial complexities of pandemics using the theory of syndemics, investigate the social and health impacts of stress and stigma, and address important methodological and ethical issues. As COVID‐19 is unlikely to be the last global pandemic, stronger involvement of biological anthropology in pandemic studies and public health policy and research is vital.

Single-cell RNA-seq of primary bone marrow neutrophils from female and male adult mice

Widespread sex-dimorphism is observed in the mammalian immune system. Consistently, studies have reported sex differences in the transcriptome of immune cells at the bulk level, including neutrophils. Neutrophils are the most abundant cell type in human blood, and they are key components of the innate immune system as they form a first line of defense against pathogens. Neutrophils are produced in the bone marrow, and differentiation and maturation produce distinct neutrophil subpopulations. Thus, single-cell resolution studies are crucial to decipher the biological significance of neutrophil heterogeneity. However, since neutrophils are very RNA-poor, single-cell profiling of these cells has been technically challenging. Here, we generated a single-cell RNA-seq dataset of primary neutrophils from adult female and male mouse bone marrow. After stringent quality control, we found that previously characterized neutrophil subpopulations can be detected in both sexes. Additionally, we confirmed that canonical sex-linked markers are differentially expressed between female and male cells across neutrophil subpopulations. This dataset provides a groundwork for comparative studies on the lifelong transcriptional sexual dimorphism of neutrophils.

Longitudinal surveillance of influenza in Japan, 2006-2016

We analysed 2006–2016 national influenza surveillance data in Japan with regards to age-, sex-, and predominant virus-related epidemic patterns and the prevalence of serum influenza virus antibodies. We found a significant increase in influenza prevalence in both children (≤ 19 years old) and adults (≥ 20 years old) over time. The influenza prevalence was higher in children (0.33 [95% CI 0.26–0.40]) than in adults (0.09 [95% CI 0.07–0.11]). Additionally, the mean prevalence of antibodies for A(H1N1)pdm09 and A(H3N2) was significantly higher in children than in adults, whereas the mean prevalence of antibodies for B lineages was relatively low in both children and adults. There was a biennial cycle of the epidemic peak in children, which was associated with a relatively higher prevalence of B lineages. The female-to-male ratios of the influenza prevalence were significantly different in children (≤ 19 years old; 1.10 [95% CI:1.08–1.13]), adults (20–59 years old; 0.79 [95% CI 0.75–0.82]), and older adults (≥ 60 years old; 1.01 [95% CI 0.97–1.04]). The significant increase in influenza prevalence throughout the study period suggests a change of immunity to influenza infection. Long-term surveillance is important for developing a strategy to monitor, prevent and control for influenza epidemics.

Gastrointestinal parasites in red-legged partridges (Alectoris rufa) hunted in Spain: a warning to game managers

Red-legged partridge (Alectoris rufa) populations are currently declining in the Iberian Peninsula, mainly due to habitat degradation and hunting pressure. In addition, the release of farm-reared partridges may introduce pathogens, including parasites, to wild populations. The presence of digestive parasites in red-legged partridges hunted in fifteen Spanish provinces was studied. Fecal samples and gastrointestinal tracts were collected, analyzed, and the morphometric identification of parasites was carried out. Eimeria spp. oocysts, nematode, cestode and trematode eggs were observed in fecal samples. Adult nematodes (Ascaridia galli, Ascaridia compar, Heterakis gallinarum, Heterakis tenuicauda, Trichostrongylus tenuis, Subulura spp., Cyrnea spp. and Aonchotheca caudinflata), tapeworms (Raillietina tetragona, R. echinobothrida, R. micracantha, Rhabdometra nigropunctata, and Choanotaenia infundibulum), and trematodes (Brachylaima spp., Brachylecithum spp., Dicrocoelium spp.) were identified in the gastrointestinal tracts. Significant statistical differences were found among climatic regions in the prevalence and intensity of Eimeria spp. infection, median intensity and the prevalence of indirect life cycle helminths, with Southern areas always showing higher infection values. The study provides information of the health status of red-legged partridges in Spain, highlighting the risk associated with the release of farm-reared partridges for restocking purposes. This should be taken into account to improve management strategies for the long-term conservation of the species.

Genetic and hormonal mechanisms underlying sex-specific immune responses in tuberculosis

Tuberculosis (TB), the world's deadliest bacterial infection, afflicts more human males than females, with a male/female (M/F) ratio of 1.7. Sex disparities in TB prevalence, pathophysiology, and clinical manifestations are widely reported, but the underlying biological mechanisms remain largely undefined. This review assesses epidemiological data on sex disparity in TB, as well as possible underlying hormonal and genetic mechanisms that might differentially modulate innate and adaptive immune responses in males and females, leading to sex differences in disease susceptibility. We consider whether this sex disparity can be extended to the efficacy of vaccines and discuss novel animal models which may offer mechanistic insights. A better understanding of the biological factors underpinning sex-related immune responses in TB may enable sex-specific personalized therapies for TB.

DEFINITION OF THE MAIN VECTOR OF CUTANEOUS LEISHMANIASIS: ECOLOGY AND MAPPING IN ENDEMIC AREA OF NORTHEAST BRAZIL

Cutaneous leishmaniasis is endemic in Pernambuco. Aiming to determine the vector species of cutaneous leishmaniasis in an endemic area of the Northeast region of Brazil, this study aimed to use the spatial mapping of human cases of CL and correlate with ecological studies of the vectors in the municipality of Timbaúba, Pernambuco, Brazil. Individuals infected with CL were recruited through active search in their homes and clinically and serologically diagnosed during the period from 2018 to 2019. Sandflies were captured with CDC-type light traps in peridomiciliary environments and these were identified at the species level. Females were separated for DNA extraction and subsequent analysis by PCR. The points of collection of phlebotomes and the residences of individuals with lesions were marked with GPS. During the study period, 60 cases of CL were diagnosed. A higher concentration of CL cases was observed in proximity to Atlantic forest remnants confirmed by heat map. A total of 3,744 sandflies was captured and five distinct species were identified, with the predominance of Nyssomyia whitmani. From the females separated for the identification of Leishmania braziliensis DNA, a rate of 0.68% of infected sandflies was obtained. It was concluded that cutaneous leishmaniasis continues to be a rural feature of the area. And from this study, it is concluded that Ny. whitmani is the carrier species of CL in the municipality of Timbaúba, Pernambuco. This is due to abundance in catching, specialization of species and PCR positivity for Leishmania braziliensis.

Serum Levels of Ficolin-3 and Mannose-Binding Lectin in Patients with Leprosy and Their Family Contacts in a Hyperendemic Region in Northeastern Brazil

The present study aimed at analyzing the serum levels of mannose-binding lectin (MBL) and ficolin-3 (FCN3) in leprosy patients and their healthy family contacts in a hyperendemic region in northeastern Brazil. A cross-sectional study was carried out with 90 patients who had been diagnosed with leprosy and 79 healthy family contacts. Serum levels of the MBL and FCN3 proteins were measured using the immunofluorometric assay (ELISA). Clinical information was determined from the patients’ charts. It was observed that the leprosy patients were more likely to be male (OR = 2.17; p = 0.01) and younger than fifteen years of age (OR = 2.01; p = 0.03) when compared to the family contacts. Those under 15 years of age had higher levels of MBL (4455 ng/mL) than those over 15 years of age (2342 ng/mL; p = 0.018). Higher FCN3 levels were identified in patients with indeterminate leprosy (41.9 µg/mL) compared to those with the lepromatous form (34.3 µg/mL; p = 0.033) and in those with no physical disabilities (38.1 µg/mL) compared to those with some disability (p = 0.031). Higher FCN3 levels were also observed in the group of patients without leprosy reactions (37.4 µg/mL) compared to those with type 1 (33.7 µg/mL) and type 2 (36.1 µg/mL) reactions. The MBL levels were higher in children under 15 years of age than they were in adults. It was evidenced that higher FCN3 serum levels were associated with early and transient clinical forms and lower expression in severe forms of leprosy.

The presence of serum anti-SARS-CoV-2 IgA appears to protect primary health care workers from COVID-19

The patterns of humoral and cellular responses to SARS-CoV-2 were studied in Swedish primary health care workers (n = 156) for 6 months during the Covid-19 pandemic. Serum IgA and IgG to SARS-CoV-2, T-cell proliferation and cytokine secretion, demographic and clinical data, PCR-verified infection, and self-reported symptoms were monitored. The multivariate method OPLS-DA was used to identify immune response patterns coupled to protection from Covid-19. Contracting Covid-19 was associated with SARS-CoV-2-specific neutralizing serum IgG, T cell, IFN-γ, and granzyme B responses to SARS-CoV-2, self-reported typical Covid-19 symptoms, male sex, higher BMI, and hypertension. Not contracting Covid-19 was associated with female sex, IgA-dominated, or no antibody responses to SARS-CoV-2, airborne allergy, and smoking. The IgG-responders had SARS-CoV-2-specific T-cell responses including a cytotoxic CD4+ T-cell population expressing CD25, CD38, CD69, CD194, CD279, CTLA-4, and granzyme B. IgA-responders with no IgG response to SARS-CoV-2 constituted 10% of the study population. The IgA responses were partially neutralizing and only seen in individuals who did not succumb to Covid-19. To conclude, serum IgG-dominated responses correlated with T-cell responses to SARS-CoV-2 and PCR-confirmed Covid-19, whereas IgA-dominated responses correlated with not contracting the infection.

The Influence of Sex, Gender, and Age on COVID-19 Data in the Piedmont Region (Northwest Italy): The Virus Prefers Men

Several important sex and gender differences in the clinical manifestation of diseases have been known for a long time but are still underestimated. The infectious Coronavirus 2019 disease pandemic has provided evidence of the importance of a sex and gender-based approach; it mainly affected men with worse symptomatology due to a different immune system, which is stronger in women, and to the Angiotensin-converting enzyme 2 and Transmembrane protease serine 2 roles which are differently expressed among the sexes. Additionally, women are more inclined to maintain social distance and smoke less. Analysis of data on the infectious Coronavirus 2019 disease testing from people admitted to the Amedeo di Savoia Hospital, a regional referral center for infectious diseases, has been applied to the whole of 2020 data (254,640 records). A high percentage of data in the dataset was not suitable due to a lack of information or entering errors. Among the suitable samples, records have been analyzed for positive/negative outcomes, matching records for unique subjects (N = 123,542), to evaluate individual recurrence of testing. Data are presented in age and sex-disaggregated ways. Analyses of the suitable sample also concerned the relation between testing and hospital admission motivation and symptoms. Our analysis indicated that a sex and gender-based approach is mandatory for patients and the National Health System’s sustainability.