Inés Oliveira

Plasmodium malariae remains one of the most neglected human malaria parasites. Historically considered of low prevalence and limited clinical significance, emerging evidence suggests its true burden may be underestimated due to diagnostic challenges and the parasite's ability to persist at low densities. A retrospective observational study was conducted at the Vall d'Hebron-Drassanes International Health Unit (Barcelona) from June 2015 to May 2025. Malaria diagnosis was performed using microscopy or quantitative PCR (qPCR), with the diagnostic method selected according to clinical presentation and epidemiological risk. Clinical and epidemiological data were collected and analyzed by descriptive statistics. Among 6,293 individuals screened for malaria, 404 (6.4%; CI 95%: 5.8-7.1) were positive for Plasmodium spp., of whom 55 (13.6%; CI 95%: 10.6-17.3) were infected with P. malariae. Most infections (52/55; 94.5%) were detected in asymptomatic migrants from sub-Saharan Africa during routine screening, with very low parasite densities (≤ 80 parasites/µL). Notably, 13/55 patients had been living in Spain for more than 12 months prior to diagnosis, supporting long-term persistence of low-level parasitemia. Furthermore, one symptomatic traveler, experienced a clinical relapse after artemisinin-based combination therapy. This study describes the trend in the diagnosis of P. malariae at a referral center in a non-endemic European setting. The high proportion of asymptomatic chronic carriers underscores a silent parasite reservoir that may hinder malaria elimination efforts. Increased awareness and improved diagnostic strategies are needed to better characterize and control this overlooked species.

Neisseria meningitidis clonal complex 11 (cc11) is a hyperinvasive lineage associated with global dissemination and outbreaks, including the ‘South American/UK’ sublineage. In Spain, cc11 serogroup W cases have increased in recent years; however, the evolutionary dynamics of circulating variants remain insufficiently characterized. This study aimed to assess the clonal diversity, temporal evolution and antimicrobial resistance profiles of cc11 isolates recovered in Spain between 2011 and 2025. A total of 1,226 isolates (406 invasive and 820 non-invasive) were collected across 8 Spanish regions, from which cc11 isolates were selected for analysis. Whole-genome sequencing (WGS) was used to perform core-genome multilocus sequence typing and SNP-based Bayesian phylogenetics to characterize population structure. Antimicrobial susceptibility was assessed using gradient diffusion, and genetic determinants of resistance were identified by WGS. We identified 179 cc11 isolates, mostly belonging to genogroup W (73.7%) and lineage 11.1 (85.5%). The ‘South American/UK’ sublineage was the main sublineage and displayed extensive diversification. A previously undescribed variant, designated the ‘2020 strain’, emerged with an estimated most recent common ancestor in 2017 and accounted for 77.2% of ‘South American/UK’ sublineage isolates recovered between 2023 and 2025. This variant was mainly identified in respiratory samples from men who have sex with men but was also associated with invasive meningococcal disease in other population groups. The ‘2020 strain’ exhibited resistance to penicillin and azithromycin, likely driven by penicillin-binding protein 2 and MtrCDE alterations. The emergence of this antimicrobial-resistant variant highlights the adaptive capacity of cc11 and the importance of genomic surveillance to monitor its evolution and public health relevance.

Background: The growing number of international travellers aged ≥60 years reflects global demographic changes and improved life expectancy. However, this group faces specific health risks due to age-related physiological changes and comorbidities, which may influence the presentation and management of travel-related illnesses. This study aimed to describe the epidemiological and clinical characteristics of imported diseases amongst older travellers compared with younger adults in Spain. Methods: A retrospective observational study was conducted using data from the Spanish National Network (+Redivi). We analysed records of travellers who sought medical care after returning to Spain between January 2011 and December 2023 in six different centres. Demographic data, travel history and final diagnoses were compared between individuals aged ≥60 years and those <60 years. Descriptive and inferential statistics were performed using R software (v4.2.2). Results: Amongst 29 573 total tourist travellers, 1230 (4.2%) involved individuals aged ≥60 years. In the traveller subgroup, 546 older and 7704 younger adults were compared. Older travellers more often undertook very short (360 days, 11.4%) trips and sought pre-travel advice less frequently (36.1%, P < 0.001). Sub-Saharan Africa and South America were the main regions of infection acquisition. Gastrointestinal disorders were the leading cause of consultation in all groups, but older adults more frequently presented with skin (22.2%) and respiratory (3.8%) symptoms. The most frequent diagnoses in the older cohort included Plasmodium falciparum malaria (4.8%), strongyloidiasis (3.3%) and chikungunya (3.5%). Conclusions: Older travellers represent a distinct and growing population within travel medicine, characterized by specific patterns of exposure and infection. These findings highlight the need for tailored pre-travel counselling and preventive strategies that consider comorbidities, vaccine limitations and extended travel durations to reduce morbidity in this vulnerable group.

Background: Schistosomiasis is a neglected tropical disease that mostly affects inhabitants of sub-Saharan Africa. With rising global migration, imported cases of schistosomiasis are increasingly being reported in non-endemic countries, where diagnosis is hindered by low parasite burdens and multiple Schistosoma species. Microscopy remains the gold standard, despite its limitations, whereas molecular techniques offer greater sensitivity. The aim of this study was to assess the performance of real-time polymerase chain reaction (PCR) protocols for the detection, at an international health centre in Barcelona, of imported cases of urogenital and intestinal schistosomiasis. Methods: This cross-sectional study included 75 adults from sub-Saharan Africa attending the Drassanes-Vall d’Hebron International Health Unit, Barcelona, between May 2023 and February 2024. Paired urine and stool samples were collected. Microscopy was performed on all samples. Urine was analysed by real-time PCR using the Dra1 target sequence. Stool was tested by three protocols targeting, respectively, Dra1, Sm1-7, and 28S rRNA. Schistosoma infection was confirmed by microscopic identification of eggs and/or parasite DNA detection by real-time PCR. Results: Schistosomiasis was confirmed in 12/75 patients (16%). Urogenital schistosomiasis was diagnosed in 3/75 cases; the performance values of real-time PCR in urine samples were not assessed. In stool, the pan- Schistosoma real-time PCR showed 55.6% sensitivity and 98.5% specificity, with a moderate agreement ( κ = 0.631) with microscopy. The Sm1-7 assay fully matched microscopy for Schistosoma mansoni detection, and reached 100% sensitivity and specificity. A novel contribution of this study is the application of a real-time PCR assay targeting the Dra1 repetitive sequence in stool samples for the detection of Schistosoma intercalatum/Schistosoma guineensis . All of the microscopy-positive cases were real-time PCR positive, and one additional infection was detected by real-time PCR, which meant that 100% sensitivity and 98.6% specificity were achieved with this technique. Conclusions: Our findings underscore the need for accurate diagnostic tools for cases of imported schistosomiasis in non-endemic settings. Microscopy remains the reference standard, while the pan- Schistosoma real-time PCR showed limited sensitivity for stool samples. In contrast, the Sm1-7 and Dra1 assays demonstrated higher sensitivity and strong concordance with microscopy, with Dra1 also proving useful for the detection of S. intercalatum / S. guineensis in stool. Graphical

: Schistosomiasis is a parasitic disease caused by trematodes of the genus Schistosoma. It is classified as a neglected tropical disease by the WHO and has the second highest morbidity of a parasitic disease after malaria. Our objective with this study was to describe radiological findings in patients diagnosed with imported schistosomiasis among migrants and international travelers seen at an international health unit. This is a descriptive, observational, single-center, retrospective study conducted at the International Health Unit, Vall d’Hebron-Drassanes, in which we analyze the radiological findings in patients diagnosed with schistosomiasis. Among the 671 individuals treated for schistosomiasis between 2014 and 2022, 132 (19.7%) underwent a radiological test, 39 (29.5%) were diagnosed with confirmed urinary schistosomiasis, 25 (18.9%) were diagnosed with intestinal schistosomiasis, and 68 (51.5%) were classified as probable cases (positive serology). In all cases, an abdominal ultrasound was performed, and eight patients (6%) also underwent an abdominal computed tomography scan. Abnormalities were found in 19 (14.4%) patients, with the most frequent findings being splenomegaly (nine cases) and bladder wall thickening (five cases). Radiological tests, especially ultrasounds, are highly useful in assessing the severity of the disease and identifying associated lesions.

: Cutaneous larva migrans (CLM) is a clinical syndrome typically found in tropical and subtropical regions. The objective of the study is to describe the epidemiological, clinical, and therapeutic characteristics of patients with CLM acquired during international travel. This retrospective observational study analyzes CLM cases treated at an international health unit in Spain. Sociodemographic, clinical, laboratory, and treatment-related data were collected. Overall, 107 cases were diagnosed, 63 (58.9%) of them in women, with a mean age of 32.6 years. Most frequent geographic regions of CLM acquisition were Southeast Asia (38 cases, 35.5%) and South America (28, 26.2%). Patients had a median of one skin lesion (range 1–11) located mainly in the lower extremities (83, 77.6%). Treatment was administered in 105 cases (98.1%), with albendazole used in 88 (83.8%), ivermectin in nine (8.6%), mebendazole in six (5.7%), and two cases lacking drug information (1.9%). Among treated cases, clinical resolution was achieved in 88 (83.8%) patients. Symptoms persisted in 17 (16.2%) cases, and recurrence was observed in 14 (13.3%) cases. A total of 26 (24.8%) patients required re-treatment with either albendazole or ivermectin (61.5% and 38.5%, respectively). The resolution rates for ivermectin, albendazole, and mebendazole were 88.9%, 88.6%, and 0.0%, respectively. CLM is a common syndrome in certain geographic regions and is more frequently diagnosed in international travelers. A thorough epidemiological assessment, along with a detailed medical history and physical examination, facilitates early diagnosis and treatment. Currently, ivermectin and albendazole appear to achieve the highest cure rates with lower recurrence rates.

Background and objective: There is little information on sexual and reproductive health knowledge (SRHK) and practices in Angola and no data on the prevalence of sexually transmitted infections. The objective of this study was to assess the SRHK and behaviors, and estimate the prevalence of four sexually transmitted infections (STIs) among adolescents and young adults from 4 municipalities in Benguela province, Angola prior to an educational intervention. Material and methods: We performed a cross-sectional study to assess SRHK and sexual behavior using a structured questionnaire among adolescents and young adults aged 15 to 25 years old from two urban and two rural municipalities of Benguela province. We also evaluated the prevalence of human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV) and syphilis using rapid tests. Results: A total of 1400 youths were included in the study. Overall, 818 (58.4%) participants had adequate SRHK. Urban origin [odds ratio (OR) 1.52, 95% confidence interval (CI) 1.35–2.04], older age (OR 1.14, 95% CI 1.09–1.20), being female (OR 2.06, 95% CI 1.57–2.71) and having journals and internet as the main sources of information (OR 1.37, 95% CI 1.00–1.86 and OR 2.33, 95% CI 1.69–3.21, respectively) were significantly associated to a good SRHK in the multivariate analysis. Four hundred and fifty-three [45.9% of those who have had sexual intercourse (n = 986)] reported risky sexual behavior. We observed that risky sexual behavior was associated with male gender (OR 2.89 95% CI 2.13–3.92, P< .001). Prevalence of STI was: 5 (0.35%) for HIV, 190 (13.6%) for HBV, 4 (0.3%) for HCV, and 20 (1.4%) for syphilis. Conclusion: SRHK was higher than expected although in-depth knowledge was uncommon, especially in men from rural areas with lack of access to journals or the internet. Unsafe sexual behavior was widespread among our sample. Prevalence of HBV was higher than expected. Sexual education campaigns using both digital and non-digital approaches should be focused on reaching the young population dispersed in rural areas where internet connection is difficult and should be accompanied by HBV vaccination promotion.

Systematic screening of tuberculosis (TB) using molecular testing on stool samples detected TB in 5.2% of acutely malnourished children, including cases without evident clinical symptoms. This screening strategy could enhance TB diagnosis and facilitate prompt treatment initiation in this population. Further studies are required to confirm long-term outcomes and cost-effectiveness.

Background: Malaria is the parasitic disease with the highest morbimortality worldwide. The World Health Organization (WHO) estimates that there were approximately 249 million cases in 2022, of which 3.4% were in Angola. Diagnosis is based on parasite identification by microscopy examination, antigen detection, and/or molecular tests, such as polymerase chain reaction (PCR). This study aimed to evaluate the usefulness of real-time PCR as a diagnostic method for malaria in an endemic area (Cubal, Angola). Methods: A cross-sectional study was carried out at the Hospital Nossa Senhora da Paz in Cubal, Angola, including 200 patients who consulted for febrile syndrome between May and July 2022. From each patient, a capillary blood sample was obtained by finger prick for malaria field diagnosis [microscopy and rapid diagnostic test (RDT)] and venous blood sample for real-time PCR performed at the Hospital Universitario Vall d’Hebron in Barcelona, Spain. Any participant with a positive result from at least one of these three methods was diagnosed with malaria. Results: Of the 200 participants included, 54% were female and the median age was 7 years. Malaria was diagnosed by at least one of the three techniques (microscopy, RDT, and/or real-time PCR) in 58% of the participants, with RDT having the highest percentage of positivity (49%), followed by real-time PCR (39.5%) and microscopy (33.5%). Of the 61 discordant samples, 4 were only positive by microscopy, 13 by real-time PCR, and 26 by RDT. Plasmodium falciparum was the most frequent species detected (90.63%), followed by P. malariae (17.19%) and P. ovale (9.38%). Coinfections were detected in ten participants (15.63%): six (60%) were caused by P. falciparum and P. malariae, three (30%) by P. falciparum and P. ovale, and one (10%) triple infection with these three species. In addition, it was observed that P. falciparum and P. malariae coinfection significantly increased the parasite density of the latter. Conclusions: RDT was the technique with the highest positivity rate, followed by real-time PCR and microscopy. The results of the real-time PCR may have been underestimated due to suboptimal storage conditions during the transportation of the DNA eluates. However, real-time PCR techniques have an important role in the surveillance of circulating Plasmodium species, given the epidemiological importance of the increase in non-falciparum species in the country, and can provide an estimate of the intensity of infection. Graphical