Endemic Populations Research Articles

Salivary antigens rPagSP02 and rPagSP06 are a reliable composite biomarker for evaluating exposure to Phlebotomus argentipes in Sri Lanka

Phlebotomus argentipes is the established vector of leishmaniasis in the Indian sub-continent. Antibodies to sand fly salivary antigens are biomarkers for vector-host exposure in leishmaniasis-endemic regions. Ph. argentipes transmits Leishmania donovani in Sri Lanka, primarily causing cutaneous leishmaniasis (CL). Our study compared the performance of salivary gland homogenate (SGH) from a lab-reared local strain of Ph. argentipes females to a composite recombinant salivary biomarker (rPagSP02 + rPagSP06) in a CL-endemic population. Sera from 546 healthy individuals, 30 CL patients, and 15 non-endemic individuals were collected. Western blot analysis of Ph. argentipes SGH identified immunogenic bands between 15 kDa and 67 kDa, with bands of predicted molecular weight ∼of 15 kDa (SP02) and ∼28–30 kDa (SP06) as the major antibody targets. Indirect ELISAs using SGH or rPagSP02 + rPagSP06 antigens showed high sensitivity (96.7%) and specificity (100%), detecting comparable seropositivity in endemic populations. rPagSP02 + rPagSP06 exhibited enhanced discriminatory ability, supported by a strong positive correlation (r = 0.869) with SGH. Our findings indicate that the composite rPagSP02 + rPagSP06 salivary biomarker effectively identifies Ph. argentipes exposure in individuals living in Sri Lanka, showing promising potential for use in surveillance. These findings should be further validated to confirm the epidemiological applications in leishmaniasis-endemic regions.

Upper tract urothelial carcinoma: epidemiology, presentation, and high-risk endemic populations.

Upper tract urothelial carcinoma (UTUC) only accounts for 5-10% of all urothelial cancers but these patients present with high stage disease and 2 out of 3 patients have evidence of muscle-invasion at time of diagnosis. Furthermore, 10% of UTUC patients have associated Lynch syndrome and therefore diagnosis of UTUC should prompt timely evaluation and familial counseling. The purpose of this review is to outline the current evidence on the epidemiology, presentation, and high-risk endemic populations of UTUC through review of contemporary publications occurring over the preceding 18 months. Both the American Urological Association (AUA) and European Association of Urology (EAU) have published updated guidelines within the last 18 months for the management of UTUC. Of note, the updated guidelines give special consideration to identifying patients with risk factors for Lynch syndrome and recommend universal histologic testing for those with high probability of having Lynch syndrome cancers as well as referral for genetic counseling and germline testing. UTUC is an overall rare malignancy but tends to present with advanced stage and muscle-invasion. A proper understanding of the epidemiology, presentation, and high-risk endemic populations is necessary to develop preventive and interventional strategies.

Depression in the schistosomiasis japonica population based on the PHQ-9 scale: a cross-sectional survey from Jiangxi Province, China

Depression is the second leading-cause of disability in China. Although studies have shown that more than 80% of patients with advanced schistosomiasis (AS) suffer from anxiety and depression, these study groups are all hospitalized patients with AS and do not represent the extent of the disease in the whole group. To our knowledge, there are no studies assessing the severity of depression in patients with other forms of schistosomiasis japonicum. Therefore, it is necessary to evaluate the occurrence and potential risk factors of depression in the schistosomiasis endemic population. This cross-sectional study was conducted in Jiangxi Province, where schistosomiasis is relatively common in China, as the investigation site. The Patient Health Questionnaire-9 (PHQ-9) scale was selected to assess the depressive symptoms in the study population. At the same time, basic personal information of the research subjects and relevant socio-economics and schistosomiasis endemic area indicators were collected. The survey results show that AS has the highest incidence of depression (34.35%), while non-advanced schistosomiasis (N-AS) and control group (CG) have 22.35% and 22.24% respectively; the incidence of depression in AS is significantly higher than in N-AS and CG, while there is no statistical significance in the comparison between N-AS and CG; the incidence of mild depressive symptoms accounts for 61.08%-75.54% of the total incidence of depression in different groups; multivariate analysis shows that the occurrence of moderate/severe depressive symptoms in the AS group was significantly related to above 60 years old, male, the combination of other serious diseases, personal financial difficulties, and marshland and lake endemic areas. In the N-AS group, the occurrence of moderate/severe depressive symptoms was significantly related to the combination of other serious diseases, personal financial difficulties, significant correlation between marshland and lake endemic areas and the level of control of schistosomiasis epidemics. In conclusion, depression is still relatively common among patients with schistosomiasis patients, especially those with AS. It is recommended that the government and relevant departments consider mental health care when developing prevention and control work in schistosomiasis-endemic areas, in order to effectively protect the physical and mental health of schistosomiasis patients and residents in endemic areas.

Cutaneous Leishmaniasis in Dr. Ersin Arslan Training and Research Hospital After Migration and During the Pandemic (2019-2022).

Cutaneous leishmaniasis is a parasitic skin disease transmitted by the bite of sandflies. In our region, which is endemic for this disease, there has been a great migration from a much more endemic region and population movements from our area to Türkiye and abroad. Afterward, a pandemic was experienced. Due to these two extraordinary events and the possible epidemic potential in our region, it is useful to follow-up on the disease. We aimed to contribute to the evaluation of the disease in these processes by analyzing the data of our laboratory in recent years. Between January 2019 and December 2022, samples from patients who came to our laboratory with suspected cutaneous leishmaniasis were taken, stained and examined under a microscope. Patients were evaluated in terms of age, gender, nationality, place of residence, lesion site and duration. Out of the 144 examined cases, 64 (44.4%) were positive for cutaneous leishmaniasis. Among these positive cases, 40 (62.5%) were women, 24 (37.5%) were men, and 54 (84.3%) belonged to the 0-9 age group. Of those who tested positive, 54 (84.3%) were Turkish citizens and 23 (35.9%) were Syrian citizens. Fifty-four (84.3%) patients had only single lesion. While the number of applications and positivity rates remained within normal levels in 2019 and 2020, a significant decrease was observed in both from 2021 and 2022. Cutaneous leishmaniasis is carried by migration, decreases in large-scale isolations such as pandemics, and its spread can be prevented with correct diagnosis and treatment. Although the number of patients may change over time and place, cutaneous leishmaniasis is a disease that threatens the health of societies and should always be monitored.

Association of Hashimoto thyroiditis with papillary thyroid carcinoma and its clinical features – A retrospective study in a tertiary care hospital

Background: Papillary thyroid carcinoma (PTC) is the most widespread endocrine malignancy. Among the several risk factors, Hashimoto thyroiditis (HT) is one of the factors associated with increased incidence of PTC. Both HT and PTC share several epidemiologic features including high prevalence, female predominance, and increased incidence in iodine-sufficient areas. Aims and Objectives: The aim of the study was to assess the incidence of HT and PTC coexistent in endemic population. The study also aimed to determine the association of various prognostic parameters of PTC in patients with coexistent HT. Materials and Methods: This was a retrospective study done from May 2019 to May 2024 over a period of 5 years in a tertiary care hospital of West Bengal. A total of 54 patients with primary PTC who underwent total thyroidectomy with cervical lymph node dissection (LND) were studied. Patients with primary PTC with neck LND and complete medical history were included in this study. Patients with previous thyroidectomy surgery or patients with incidental PTC diagnosed in thyroidectomy specimens done for a benign neoplasm (without LND) were excluded from the study. Results: A total of 54 cases of PTC were studied out of which 23 cases were PTC associated with HT and 31 cases were PTC without HT constituting 42.59% and 57.4%, respectively. PTC associated with HT had a greater incidence in females. In this study, our results showed that PTC with HT had a greater tendency of tumor multifocality, greater mean lymph node size, and increase rate of extranodal tumor extension. At the same time, patients of PTC associated with HT had smaller tumor size and low clinical stage. Conclusion: PTC associated with HT had a female preponderance, larger metastatic lymph node, a tendency for multifocality, and extranodal extension. At the same, they also had smaller tumor size and low clinical stage indicating a complex and controversial effect of HT on PTC.

Comparative evaluation of plasma biomarkers of Schistosoma haematobium infection in endemic populations from Burkina Faso.

Infection with Schistosoma haematobium causes urogenital disease associated with organ disfunction, bleeding, pain, and higher susceptibility to infections and cancer. Timely and accurate diagnosis is crucial for prompt and appropriate treatment as well as surveillance efforts, and the use of plasma biomarkers offers important advantages over parasitological examination of urine, including increased sensitivity and the possibility to use the same specimen for multiple investigations. The present study aims to evaluate the diagnostic performance of different plasma biomarkers in endemic populations from Burkina Faso, West Africa. Schistosoma spp. Circulating Anodic Antigen (CAA), cell free S. haematobium DNA (cfDNA), class M and G antibodies against S. haematobium Soluble Worm Antigen Preparation (SWAP) and Soluble Egg Antigen (SEA) were measured in 406 plasma samples. Results of each biomarker test were compared to those of CAA, a Composite Reference Standard (CRS) and Latent Class Analysis (LCA). An identical proportion of positive samples (29%) was observed as a result of CAA and cfDNA testing, with a substantial agreement (84%, Cohen k = 0.62) between the results of the two tests, and a comparable agreement with the results of CRS and LCA. A higher positivity was observed, as expected, as a result of specific antibody testing (47%-72%), with IgG showing a higher agreement than IgM with the three references. Also, higher IgG levels were observed in current vs past infection, and ROC analysis identified optimal cutoff values for improved testing accuracy. This study provides compelling evidence that can inform the choice of the most appropriate diagnostic plasma biomarker for urogenital schistosomiasis in endemic areas, depending on the purpose, context, and available resources for testing. Either CAA or cfDNA testing can be used for the diagnosis of patients and for epidemiological investigations, even in absence of urine filtration microscopy, whereas anti-SWAP or anti-SEA IgG can be employed for surveillance and integrated monitoring of control interventions against poverty-associated diseases.

Cost-effectiveness of mass drug administration for control of scabies in Ethiopia: a decision-analytic model.

The strategies to control scabies in highly endemic populations include individual case/household management and mass drug administration (MDA). We used a decision-analytic model to compare ivermectin-based MDA and individual case/household management (referred to as "usual care") for control of scabies in Ethiopia at different prevalence thresholds for commencing MDA. A decision-analytic model was based on a repeated population survey conducted in Northern Ethiopia in 2018-2020, which aimed to evaluate the secondary impact of single-dose ivermectin MDA for the control of onchocerciasis on scabies prevalence. The model estimates the number of scabies cases and costs of two treatment strategies (MDA and usual care) based on their effectiveness, population size, scabies prevalence, compliance with MDA, medication cost, and other parameters. In the base-case analysis with a population of 100,000 and scabies prevalence of 15%, the MDA strategy was both more effective and less costly than usual care. The probability of MDA being cost-effective at the current cost-effectiveness threshold (equivalent to the cost of usual care) was 85%. One-way sensitivity analyses showed that the MDA strategy remained dominant (less costly and more effective) in 22 out of 26 scenarios. MDA was not cost-effective at scabies prevalence <10%, MDA effectiveness <85% and population size <5,000. An increase in the cost of ivermectin from 0 (donated) to 0.54 US$/dose resulted in a decrease in the probability of MDA being cost-effective from 85% to 17%. At 0.25 US$/dose, the MDA strategy was no longer cost-effective. The model provides robust estimates of the costs and outcomes of MDA and usual care and can be used by decision-makers for planning and implementing scabies control programmes. Results of our analysis suggest that single-dose ivermectin MDA is cost-effective in scabies control and can be initiated at a scabies prevalence >10%.

From bench to clinic: the development of VLA1553/IXCHIQ, a live-attenuated chikungunya vaccine.

Over the past 20 years, over 5 million cases of chikungunya, a mosquito-transmitted viral disease, have been reported in over 110 countries. Until recently, preventative strategies for chikungunya were largely ineffective, relying on vector control and individual avoidance of mosquito bites. This review outlines the preclinical and clinical efficacy and safety data that led to the approval of VLA1553 (IXCHIQ®), a live-attenuated vaccine against chikungunya disease. It also describes the innovative development pathway of VLA1553, based on an immunological surrogate of protection, and discusses ongoing and future post-licensure studies. In mice and non-human primate models, VLA1553 elicited high titres of neutralizing antibodies, conferred protection against wild-type chikungunya virus challenge and raised no safety concerns. A Phase 1 clinical trial of VLA1553 demonstrated 100% seroconversion among 120 healthy participants, with sustained neutralizing antibody titres after 12 months. These results and determination of a surrogate marker of protection led to advancement of VLA1553 directly into Phase 3 clinical development, as agreed with the US Food and Drug Administration (FDA) and the European Medicines Agency. The pivotal Phase 3 trial met its primary immunogenicity endpoint, achieving seroprotective levels based on immuno-bridging in baseline seronegative participants 28 days post-vaccination. These findings enabled submission of a Biologics License Application to the FDA for accelerated approval of VLA1553 in the US for adults aged ≥18 years. Ongoing and planned studies will confirm the clinical efficacy/effectiveness and safety of VLA1553 in adults and younger individuals, and will generate data in chikungunya endemic countries that have the highest unmet need. VLA1553 is the first vaccine approved for the prevention of chikungunya disease in adults, following accelerated development based on a serological surrogate marker of protection. VLA1553 adds to strategies to reduce the spread and burden of chikungunya in endemic populations and travellers.

The Cardiac Manifestations of Post-streptococcal Infection in Paediatrics: Case Series

Introduction: Group A streptococcus (GAS) remains a global burden, particularly in developing countries, with long-term morbidity and mortality complications. Different strains and immune responses to GAS can lead to various disease patterns, from predominantly throat and skin manifestations to renal and cardiac involvement. Myocarditis associated with glomerulonephritis can progress to carditis, which may present with signs and symptoms similar to rheumatic heart disease. Although uncommon, this condition can deteriorate into dilated cardiomyopathy, potentially leading to cardiogenic shock and death, necessitating early recognition, intervention, and preventive measures. Case Presentation: We report three pediatric cases of post-streptococcal infection with cardiac manifestations. The first case involves an 8-year-old female with palpitations and a recurring cough, diagnosed with acute rheumatic carditis. The second case is a 10-year-old female presenting with hemoptysis and edema in the lungs and extremities due to acute rheumatic carditis and prior suspected vegetation. The third case is a 9-year-old male initially diagnosed with post-streptococcal glomerulonephritis (PSGN), who deteriorated into dilated cardiomyopathy with an ejection fraction of 32% and multiple organ dysfunction syndrome. All three patients recovered well, received prophylactic management, and were referred for further investigation. Conclusions: Identifying specific features on echocardiography can help differentiate between rheumatic heart disease (RHD) and PSGN-associated cardiac involvement. Additionally, echocardiography is a more readily available and cost-effective screening method, especially in endemic populations. Early recognition and management of post-streptococcal cardiac complications may prevent long-term morbidity and mortality.

Extensive transmission and variation in a functional receptor for praziquantel resistance in endemic Schistosoma mansoni.

Mass-drug administration (MDA) of human populations using praziquantel monotherapy has become the primary strategy for controlling and potentially eliminating the major neglected tropical disease schistosomiasis. To understand how long-term MDA impacts schistosome populations, we analysed whole-genome sequence data of 570 Schistosoma mansoni samples (and the closely related outgroup species, S. rodhaini) from eight countries incorporating both publicly-available sequence data and new parasite material. This revealed broad-scale genetic structure across countries but with extensive transmission over hundreds of kilometres. We characterised variation across the transient receptor potential melastatin ion channel, TRPMPZQ, a target of praziquantel, which has recently been found to influence praziquantel susceptibility. Functional profiling of TRPMPZQ variants found in endemic populations identified four mutations that reduced channel sensitivity to praziquantel, indicating standing variation for resistance. Analysis of parasite infrapopulations sampled from individuals pre- and post-treatment identified instances of treatment failure, further indicative of potential praziquantel resistance. As schistosomiasis is targeted for elimination as a public health problem by 2030 in all currently endemic countries, and even interruption of transmission in selected African regions, we provide an in-depth genomic characterisation of endemic populations and an approach to identify emerging praziquantel resistance alleles.

Hepatitis B Screening Profile, Epidemiological and Clinical Characteristics in a Highly Endemic Population in Southern Nigeria

Hepatitis B Screening Profile, Epidemiological and Clinical Characteristics in a Highly Endemic Population in Southern Nigeria

Arthropod traits as proxies for abundance trends in the Azorean Islands

Human activities drive ecological transformation, impacting island ecosystems from species diversity to ecological traits, mainly through habitat degradation and invasive species. Using two unique long‐term datasets we aim to evaluate whether species traits (body size, trophic level, dispersal capacity and habitat occupancy) can predict temporal variations in the abundance of endemic, indigenous (endemic and native non‐endemic) and exotic arthropods in the Azores Islands. We found that body size is crucial to predict arthropod abundance trends. Small‐bodied herbivorous arthropods showed a decrease in abundance, while large‐bodied indigenous arthropods increased in abundance, mainly in well‐preserved areas. Also, large‐bodied exotic arthropods increased in abundance across the entire archipelago. Moreover, endemic canopy dwellers increased in abundance, while endemic ground‐dwellers decreased in abundance. Simultaneously, exotic arthropods showed the opposite result, increasing in abundance in the ground while decreasing in abundance in the canopy. Finally, habitat influenced both endemic and exotic spider abundance trends. Endemic spiders that occupy solely natural habitats experienced a decline in abundance, while exotic spiders in the same habitats increased in abundance. Our study underscores the significance of arthropod species traits in predicting abundance changes in island ecosystems over time, as well as the importance of monitoring species communities. Conservation efforts must extend beyond endangered species to protect non‐threatened ones, given the increased extinction risk faced by even common species on islands. Monitoring and restoration programs are essential for preserving island ecosystems and safeguarding endemic arthropod populations.

Dynamics of IgM and IgG Antibody Response Profile against Linear B-Cell Epitopes from Exoerythrocytic (CelTOS and TRAP) and Erythrocytic (CyRPA) Phases of Plasmodium vivax: Follow-Up Study.

Malaria is a serious health problem worldwide affecting mainly children and socially vulnerable people. The biological particularities of P. vivax, such as the ability to generate dormant liver stages, the rapid maturation of gametocytes, and the emergence of drug resistance, have contributed to difficulties in disease control. In this context, developing an effective vaccine has been considered a fundamental tool for the efficient control and/or elimination of vivax malaria. Although recombinant proteins have been the main strategy used in designing vaccine prototypes, synthetic immunogenic peptides have emerged as a viable alternative for this purpose. Considering, therefore, that in the Brazilian endemic population, little is known about the profile of the humoral immune response directed to synthetic peptides that represent different P. vivax proteins, the present work aimed to map the epitope-specific antibodies' profiles to synthetic peptides representing the linear portions of the ookinete and sporozoite cell passage protein (CelTOS), thrombospondin-related adhesive protein (TRAP), and cysteine-rich protective antigen (CyRPA) proteins in the acute (AC) and convalescent phases (Conv30 and Conv180 after infection) of vivax malaria. The results showed that the studied subjects responded to all proteins for at least six months following infection. For IgM, a few individuals (3-21%) were positive during the acute phase of the disease; the highest frequencies were observed for IgG (28-57%). Regarding the subclasses, IgG2 and IgG3 stood out as the most prevalent for all peptides. During the follow-up, the stability of IgG was observed for all peptides. Only one significant positive correlation was observed between IgM and exposure time. We conclude that for all the peptides, the immunodominant epitopes are recognized in the exposed population, with similar frequency and magnitude. However, if the antibodies detected in this study are potential protectors, this needs to be investigated.

The impact of the National Programme to Eliminate Lymphatic Filariasis on filariasis morbidity in Sri Lanka: Comparison of current status with retrospective data following the elimination of lymphatic filariasis as a public health problem.

Sri Lanka implemented the National Programme for Elimination of Lymphatic Filariasis (NPELF) in its endemic regions in 2002. Five annual rounds of mass drug administration using the two-drug combination diethylcarbamazine (DEC) and albendazole led to sustained reductions in infection rates below threshold levels. In 2016, WHO validated that Sri Lanka eliminated lymphatic filariasis as a public health problem. To explore the impact of the NPELF on lymphatic filariasis morbidity in Sri Lanka. Passive Case Detection (PCD) data maintained in filaria clinic registries from 2006-2022 for lymphoedema and hospital admission data for managing hydroceles/spermatoceles from 2007-2022 were analyzed. The morbidity status in 2022 and trends in overall and district-wise PCD rates were assessed. Poisson log-linear models were used to assess the trends in PCD for endemic regions, including district-wise trends and hospital admissions for the management of hydroceles/spermatoceles. In 2022, there were 566 new lymphoedema case visits. The mean (SD) age was 53.9 (16.0) years. The staging was done for 94% of cases, of which 79% were in the early stages (57.3% and 21.4% in stages two and one, respectively). Western Province had the highest caseload (52%), followed by the Southern (32%) and Northwestern (16%) Provinces, respectively. The reported lymphoedema PCD rate in 2022 was 0.61 per 10,000 endemic population. The overall PCD rate showed a decline of 7.6% (95%CI: 4.9% - 10.3%) per year (P < 0.0001) from 2007 to 2022. A steady decline was observed in Colombo, Gampaha and Kurunegala districts, while Kalutara remained static and other districts showed a decline in recent years. Further, admissions for inpatient management of hydroceles/spermatoceles showed a declining trend after 2015. The PCD rates of lymphoedema and hydroceles/spermatoceles showed a declining trend in Sri Lanka after the implementation of the NPELF.

Population genetic structure of the endemic sponge Lubomirskia baikalensis in Lake Baikal in the light of mass disease and mortality events

Abstract The study of the state of Baikal endemic sponge populations is of great interest because of the occurrence of mass mortalities and disease in recent decades. To identify possible signs of species vulnerability to extinction, it is crucial to develop appropriate genetic markers that help developing measures for conservation. In this paper, we describe the population genetic structure of the Baikal endemic sponge Lubomirskia baikalensis examined with the set of microsatellite markers we developed. We analysed 251 samples from eight locations that cover all three basins of Lake Baikal. A genetic subdivision into three clusters was revealed. Such a structure can be explained mainly by the low ability of larvae to disperse. Despite the presence of dead and diseased individuals in all studied locations, all populations were in Hardy–Weinberg equilibrium and no bottleneck effect was found at all. This is the first time that a genetic connectivity study has been performed for L. baikalensis, a species endemic of Lake Baikal. Reconstruction of the changes in the effective population size agrees with the results obtained during drill sample analysis and it demonstrates that the effective population size was 55.5 times lower about 24,000 years ago, which indicates that apparently there is no threat of extinction of the Baikal endemic sponges at present.

Determinants of immune responses predictive of protection against shigellosis in an endemic zone: a systems analysis of antibody profiles and function

Shigella is the third leading global cause of moderate or severe diarrhoea among children younger than 5years globally, and is the leading cause in children aged 24-59months. The mechanism of protection against Shigella infection and disease in endemic areas is uncertain. We aimed to compare the Shigella-specific antibody responses in individuals living in Shigella-endemic and non-endemic areas, and to identify correlates of protection in a Shigella-endemic location. We applied a systems approach to retrospectively analyse serological responses to Shigella across endemic and non-endemic populations. We profiled serum samples collected from 44individuals from the USA without previous exposure to Shigella and who were experimentally challenged with Shigella sonnei (non-endemic setting), and serum samples collected from 55Peruvian army recruits (endemic setting). In the endemic setting, a subset of 37samples collected from individuals infected with culture-confirmed Shigella flexneri 2a were divided into twogroups: susceptible, which included individuals infected within 90days of entering the camp (n=29); or resistant, which included individuals infected later than 90days after entering the camp (n=8). We analysed Shigella-specific antibody isotype, subclass, and Fc receptor binding profiles across IpaB, IpaC, IpaD, and lipopolysaccharide from Sflexneri 2a, 3a, and 6, and Ssonnei, and O-specific polysaccharide (OSP) from Sflexneri 2a and 3a and Ssonnei. We also evaluated antibody-mediated complement deposition and innate immune cell activation. The main outcome of interest was the detection of antibody markers and functionality associated with protection against shigellosis in a high-burden endemic setting. Adults with endemic exposure to Shigella possessed broad and functional antibody responses across polysaccharide, glycolipid, and protein antigens compared with individuals from non-endemic regions. In a setting with high Shigella burden, elevated levels of OSP-specific Fcα receptor (FcαR) binding antibodies were associated with resistance to shigellosis, whereas total OSP-specific IgA was not, suggesting a potentially unique functionality. OSP-specific FcαR binding IgA found in resistant individuals activated bactericidal neutrophil functions including phagocytosis, degranulation, and production of reactive oxygen species. Moreover, IgA depletion from resistant serum significantly reduced binding of OSP-specific antibodies to FcαR and antibody-mediated activation of neutrophils and monocytes. Our findings suggest that OSP-specific functional IgA responses contribute to protective immunity against Shigella infection in a high-burden setting. These findings will assist in the development and evaluation of Shigella vaccines. US National Institutes of Health.

RPagSP02+rPagSP06 recombinant salivary antigen is a reliable biomarker for evaluating exposure to Phlebotomus argentipes in Sri Lanka.

Phlebotomus argentipes is the established vector of leishmaniasis in the Indian sub-continent. Antibodies to sand fly salivary antigens are biomarkers for vector-host exposure in leishmaniasis-endemic regions. Ph. argentipes transmits Leishmania donovani in Sri Lanka, primarily causing cutaneous leishmaniasis (CL). Our study compared the performance of salivary gland homogenate (SGH) from a lab-reared local strain of Ph. argentipes females to a composite recombinant salivary biomarker (rPagSP02 + rPagSP06) in a CL-endemic population. Sera from 546 healthy individuals, 30 CL patients, and 15 non-endemic individuals were collected. Western blot analysis of Ph. argentipes SGH identified immunogenic bands between 15 kDa and 67 kDa, with bands of predicted molecular weight ∼of 15 kDa (SP02) and ∼28-30 kDa (SP06) as the major antibody targets. Indirect ELISAs using SGH or rPagSP02 + rPagSP06 antigens showed high sensitivity (96.7%) and specificity (100%), detecting comparable seropositivity in endemic populations. rPagSP02 + rPagSP06 exhibited enhanced discriminatory ability, supported by a strong positive correlation (r = 0.869) with SGH. Our findings indicate that the composite rPagSP02 + rPagSP06 salivary biomarker effectively identifies Ph. argentipes exposure in individuals living in Sri Lanka, showing promising potential for use in surveillance. These findings should be further validated to confirm the epidemiological applications in leishmaniasis-endemic regions.

Genetic diversity of Cryptosporidium species from diarrhoeic ungulates in the United Arab Emirates

Cryptosporidiosis has previously been reported in animals, humans, and water sources in the United Arab Emirates (UAE). However, most reports were only to the genus level, or generically identified as cryptosporidiosis. We aimed to investigate the genetic diversity of Cryptosporidium species occurring in diarrhetic ungulates which were brought to the Central Veterinary Research Laboratory (CVRL) in Dubai. Using a combination of microscopic and molecular methods, we identified five species of Cryptosporidium occurring among ungulates in the UAE, namely C. parvum, C. hominis, C. xiaoi, C. meleagridis, and C. equi. Cryptosporidium parvum was the most prevalent species in our samples. Furthermore, we identified subtypes of C. parvum and C. hominis, which are involved in both human and animal cryptosporidiosis. This is also the first reported occurrence of Cryptosporidium spp. in the Arabian Tahr, to our knowledge. Since the animals examined were all in contact with humans, the possibility of zoonotic spread is possible. Our study correlates with previous reports in the region, building upon the identification of Cryptosporidium sp. However, there is a need to further investigate the endemic populations of Cryptosporidium, including more hosts, sampling asymptomatic animals, and location data.

Complete genome sequence of Vibrio parahaemolyticus ST36 strain MAVP-26, a clinical isolate from an oyster-borne human gastric infection.

A Pacific native lineage of Vibrio parahaemolyticus ST36 serotype O4:K12 was introduced into the Atlantic, which increased local source illnesses. To identify genetic determinants of virulence and ecological resiliency and track their transfer into endemic populations, we constructed a complete genome of a 2013 Atlantic-traced clinical isolate by hybrid assembly.

Drone-based early detection of bark beetle infested spruce trees differs in endemic and epidemic populations

IntroductionEuropean forests face increasing threats due to climate change-induced stressors, which create the perfect conditions for bark beetle outbreaks. The most important spruce forest pest in Europe is the European Spruce Bark Beetle (Ips typographus L.). Effective management of I. typographus outbreaks necessitates the timely detection of recently attacked spruce trees, which is challenging given the difficulty in spotting symptoms on infested tree crowns. Bark beetle population density is one of many factors that can affect infestation rate and symptoms development. This study compares the appearance of early symptoms in endemic and epidemic bark beetle populations using highresolution Unmanned Aerial Vehicles (UAV) multispectral imagery.MethodsIn spring of 2022, host colonization by bark beetles was induced on groups of spruce trees growing in 10 sites in the Southern Alps, characterized by different population density (5 epidemic and 5 endemic). A multispectral sensor mounted on a drone captured images once every 2 weeks, from May to August 2022. The analyses of a set of vegetational indices allowed the actual infested trees’ reflectance features and symptoms appearance to be observed at each site, comparing them with those of unattacked trees.ResultsResults show that high bark beetles population density triggers a more rapid and intense response regarding the emergence of symptoms. Infested trees were detected at least 1 month before symptoms became evident to the human eye (red phase) in epidemic sites, while this was not possible in endemic sites. Key performing vegetation indices included NDVI (Normalized Difference Vegetation Index), SAVI (Soil Adjust Vegetation Index, with a correction factor of 0.44), and NDRE (Normalized Difference Red Edge index).DiscussionThis early-detection approach could allow automatic diagnosis of bark beetles’ infestations and provide useful guidance for the management of areas suffering pest outbreaks.