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Background Schistosomiasis due to the species Schistosoma intercalatum/guineensis , which had been traditionally classified as a single species, is one of the least studied. This work describes epidemiological, clinical and microbiological characteristics of patients with S. intercalatum/guineensis infection. Methods A retrospective study was performed. The aim was to showcase a clinical overview of this rarely described disease All cases diagnosed of schistosomiasis by S. intercalatum/guineensis at the International Health Unit Vall d’Hebron-Drassanes (Infectious Diseases Department, Vall d’Hebron University Hospital, Barcelona, Spain) from January 2014 to April 2020 were included. The diagnosis was defined by the observation of S. intercalatum/guineensis eggs. Demographic, clinical, and microbiological data were analyzed. Results Seventy-four patients were included. Forty-seven (63.5%) of them were women, with a mean age of 24 (SD 12.8) years, and a mean time of residence in Spain of 9 (SD 20.7) months. All of them were migrants from Sub-Saharan Africa, 71 (95.9%) from Equatorial Guinea. Sixty-three (85.1%) patients had concomitant infections at the time of diagnosis and 50% of patients were symptomatic; abdominal pain and diarrhea being the more frequent. Anemia was detected in 25 (33.8%) patients, eosinophilia in 45 (60.8%), and hyperIgE in 48 (64.5%). Overall, 70 (94.6%) patients received treatment with praziquantel at 40 mg/kg/day in different scheme dosage. Post-treatment microscopic examination of the stools was negative in all the cases performed. Conclusions Patients affected by S. intercalatum/guineensis infection come from a specific area of Central Africa. Co-infection with other parasites is very frequent, and symptoms are present in roughly 50% of patients. No cases of hepatic complications were detected but intestinal symptoms and anemia are frequent in these patients.

Antitrypanosomal treatment with Benznidazole (BZ) or Nifurtimox may be recommended for patients with chronic Chagas disease (CD) to reduce the onset or progression of symptoms. However, such treatment has limited efficacy and high level of toxic effects. In addition, the current cure biomarker (serology conversion) precludes any treatment assessment unless a prolonged follow-up is arranged. PCR is thus the most useful, alternative surrogate marker for evaluating responses to treatment. The aim of this study is to describe the usefulness of real-time PCR in monitoring BZ treatment within a large cohort of chronic CD cases in Barcelona. A total of 370 chronic CD patients were monitored with real-time PCR post-BZ treatment. The median follow-up was 4 years (IQR 2.2-5.3y), with a median of 3 clinical visits (IQR 2-4). Only 8 patients (2.2%) presented with at least one incident of positive real-time PCR after treatment and were therefore considered as treatment failure. Four of those failure patients had completed full course treatment, whereas the remaining cases had defaulted with a statistical difference between both groups (p = 0.02). Half of the failure patients had undergone less than 4 years of follow-up monitoring all presented with parasitemia before treatment. BZ treatment failure was highly infrequent in our cohort. BZ discontinuation was a risk factor for positive real-time PCR results during clinical follow-up. Regular testing with real-time PCR during follow-up allows for early detection of treatment failure in patients with chronic CD.

Background Malaria remains a major cause of morbidity and mortality in Angola, where Plasmodium falciparum accounts for most infections. The widespread use of artemether–lumefantrine (AL) as first-line treatment and sulfadoxine–pyrimethamine (SP) for intermittent preventive treatment in pregnancy (IPTp) exerts selective pressure on local parasite populations. Molecular surveillance of drug resistance markers is essential to monitor susceptibility and anticipate changes that may influence treatment and prevention strategies. This study analyzed pfk13 , pfmdr1 , pfdhfr , and pfdhps polymorphisms in P. falciparum isolates from Cubal, Benguela province, to assess parasite genetic evolution under AL and SP pressure. Methods A cross-sectional study was conducted between 2022 and 2023 at Hospital Nossa Senhora da Paz (Cubal). A total of 139 real-time PCR–confirmed P. falciparum infections were included. Dried blood spot samples underwent sequencing of the genes involved in resistance. Mutation and haplotype frequencies associated with antimalarial resistance were determined. Results Among 120 pfk13 sequences, mutations were detected in 12 isolates (10%), including five nonsynonymous variants, but none corresponded to validated or candidate markers of artemisinin resistance. In pfmdr1 (100 sequences), Y184F was the most prevalent mutation (43%), N86Y was rare (1%), and D1246Y was not detected. Seven additional pfmdr1 variants were identified. Of the 101 isolates correctly sequenced for pfdhfr / pfdhps , 77.2% carried the triple pfdhfr N51I/C59R/S108N mutation. In pfdhps , A437G was nearly fixed (98%), K540E showed moderate prevalence (23.8%), and A581G was absent. The most common pfdhps haplotypes were ISGKAA (64.4%) and ISGEAA (22.8%). Combined pfdhfr / pfdhps profiles classified 58.4% of isolates as “partially resistant” (IRNG) and 17.8% as “fully resistant” (IRNGE), with no “super-resistant” haplotypes. Additional single mutations not associated with SP resistance were also detected. Conclusions This study provides an updated molecular profile of antimalarial resistance in a rural area of Angola. No validated or candidate pfk13 markers of artemisinin resistance were identified. However, the predominance of pfmdr1 haplotypes linked to reduced lumefantrine susceptibility raises concerns regarding AL efficacy. Although SP remains suitable for IPTp, the presence of the “fully resistant” haplotype (IRNGE) of pfdhfr / pfdhps highlight potential risks to long-term effectiveness. These findings reinforce the need for integrated molecular surveillance and periodic therapeutic efficacy studies to guide malaria control policies in rural Angola.

The human immunodeficiency virus (HIV) remains a leading cause of maternal morbidity and mortality in Sub-Saharan Africa. Prevention of mother-to-child transmission (PMTCT) has proven an effective strategy to end paediatric infections and ensure HIV-infected mothers access treatment. Based on cross-sectional data collected from June 2008 to May 2013, we assessed changes in HIV prevalence, risk factors for HIV, provision of PMTCT antiretroviral treatment (ART), and the association between HIV infection, birth outcomes and maternal characteristics at the Simão Mendes National Hospital, Guinea-Bissau’s largest maternity ward. Among 24,107 women, the HIV prevalence was 3.3% for HIV-1, 0.8% for HIV-2 and 0.9% for HIV-1/2. A significant decline in HIV-1, HIV-2, and HIV-1/2 prevalence was observed over time. HIV infection was associated with age and ethnicity. A total of 85% of HIV-infected women received ART as part of PMTCT, yet overall treatment coverage during labour and delivery declined significantly for both mothers and infants. Twenty-two percent of infants did not receive treatment, and 67% of HIV-2-infected mothers and 77% of their infants received ineffective non-nucleoside reverse transcriptase inhibitors for PMTCT. Maternal HIV was associated with low birth weight but not stillbirth. Inadequate continuity of care and ART coverage present challenges to optimal PMTCT in Guinea-Bissau.

Immunosuppression, which has become an increasingly relevant clinical condition in the last 50 years, modifies the natural history of Trypanosoma cruzi infection in most patients with Chagas disease. The main goal in this setting is to prevent the consequences of reactivation of T. cruzi infection by close monitoring. We analyze the relationship between Chagas disease and three immunosuppressant conditions, including a description of clinical cases seen at our center, a brief review of the literature, and recommendations for the management of these patients based on our experience and on the data in the literature. T. cruzi infection is considered an opportunistic parasitic infection indicative of AIDS, and clinical manifestations of reactivation are more severe than in acute Chagas disease. Parasitemia is the most important defining feature of reactivation. Treatment with benznidazole and/or nifurtimox is strongly recommended in such cases. It seems reasonable to administer trypanocidal treatment only to asymptomatic immunosuppressed patients with detectable parasitemia, and/or patients with clinically defined reactivation. Specific treatment for Chagas disease does not appear to be related to a higher incidence of neoplasms, and a direct role of T. cruzi in the etiology of neoplastic disease has not been confirmed. Systemic immunosuppressive diseases or immunosuppressants can modify the natural course of T. cruzi infection. Immunosuppressive doses of corticosteroids have not been associated with higher rates of reactivation of Chagas disease. Despite a lack of evidence-based data, treatment with benznidazole or nifurtimox should be initiated before immunosuppression where possible to reduce the risk of reactivation. Timely antiparasitic treatment with benznidazole and nifurtimox (or with posaconazole in cases of therapeutic failure) has proven to be highly effective in preventing Chagas disease reactivation, even if such treatment has not been formally incorporated into management protocols for immunosuppressed patients. International consensus guidelines based on expert opinion would greatly contribute to standardizing the management of immunosuppressed patients with Chagas disease.

To determine the epidemiologic and clinical characteristics of patients in Spain with imported arbovirus infections, we analyzed 22,655 records from a collaborative network for January 2009-December 2018. Among 861 arbovirus infections, 845 were monoinfections (456 [53%] dengue, 280 [32.5%] chikungunya, 109 [12.7%] Zika) and 16 (1.8%) were co-infections. Most patients were travelers (56.3%) or immigrants returning to Spain after visiting friends or relatives (31.3%). Median patient age was 37 years; most (62.3%) were women and some (28.6%) had received pretravel advice. Only 12 patients were immunosuppressed. Six cases (all dengue monoinfections, none in immunosuppressed patients) were severe. Since 2014, nondengue arbovirus infections increased; until 2016, chikungunya and Zika were most common. Imported arbovirus infections (mostly dengue) were frequently diagnosed, although increased chikungunya and Zika virus infections coincided with their introduction and spread in the Americas. A large proportion of cases occurred in women of childbearing age, some despite receipt of pretravel advice.

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 abstract

Background Rapid diagnostic tests (RDTs) based on Plasmodium falciparum histidine-rich protein 2 ( Pf HRP2-RDTs) are widely used for malaria diagnosis. However, the efficacy of Pf HRP2-RDTs is compromised by deletions and genetic variations in the pfhrp2 and pfhrp3 genes. In addition, antigen variability, including diverse protein variants and epitope profiles, can affect the sensitivity of RDTs. This study aimed to report the frequency and genetic variability of pfhrp2 and pfhrp3 deletions and to assess Pf HRP2 and Pf HRP3 protein variability by analysing their impact on RDT performance in Cubal, a rural area in western Angola. Methods Samples were collected at the Hospital Nossa Senhora da Paz in Cubal from May to July 2022. A total of 100 dried blood samples from febrile patients were confirmed positive for Plasmodium spp. by real-time PCR. The diagnosis of malaria was validated by thick blood smear microscopy and RDT targeting Pf HRP2 and pan-malarial lactate dehydrogenase. Deletions in pfhrp2 and pfhrp3 were assessed by PCR amplification of exons 1–2 and 2. Exon 2 sequences were analysed for amino acid repeats and candidate epitopes, and samples were sorted according to predicted RDT sensitivity. Results Species identification revealed that 96% were infected with P. falciparum and were included in the analyses; deletions in exon 1–2 were found in 7.29% ( pfhrp2 ) and 11.46% ( pfhrp3 ). No deletions were observed in exon 2 of pfhrp2 or pfhrp3 . Protein analysis revealed significant variability in histidine repeats between RDT sensitivity groups. In Pf HRP2, epitopes 3A4 and C1-13 were present in 100% of the samples, with the highest frequencies per isolate being observed (15 and 18 times per isolate, respectively). Conclusions The low prevalence of deletions in pfhrp2 and the absence of double deletions in pfhrp2 / 3 , together with the good performance of Pf HRP2-RDT suggest that these tests are a suitable diagnostic tool in Cubal. However, continued monitoring of pfhrp2 and pfhrp3 deletions is essential to ensure long-term efficacy. Pf HRP2 variability may influence RDT performance; however, further research is needed to clarify its precise impact. These findings enhance the understanding of the genetic variability and structure of Pf HRP2 and Pf HRP3, highlighting the potential of Pf HRP2-RDTs targeting the 3A4 and C1-13 epitopes for improved malaria diagnosis. Graphical abstract

Current guidelines recommend treating chronic Chagas disease (CD) with benznidazole up to 50 years of age, with individualized decisions in older individuals due to limited safety data. We aimed to compare the safety, tolerability and long-term outcomes of benznidazole in individuals above and below 50 years. We conducted a retrospective cohort study at Vall d’Hebron-Drassanes (Barcelona), including individuals aged 35-69 years treated with benznidazole between 2008 and 2017. Participants were divided into two age groups: (35-49 and 50-69 years), with biannual follow-up. The primary outcome was treatment discontinuation due to toxicity. Secondary outcomes included adverse events (AEs), cardiac progression, and other clinical events over 5 years. A total of 339 patients were included, of whom 59 (17.4%) were ≥50 years. AEs occurred in 82% of individuals, with no significant differences between groups (p = 0.50). Cutaneous reactions were the most frequent AEs (54%), and did not differ significantly by age (57% vs. 46%, p = 0.11). Treatment discontinuation due to toxicity was similar in older and younger individuals (20.3% vs. 13.7%; p = 0.19). Cardiac progression was more frequent in older individuals (1.73 vs. 0.68 events/100 person-years; p = 0.03), though this was not significant after adjustment (p = 0.52). New cardiovascular risk factors and malignancies were more frequent in older individuals. Benznidazole was associated with a high frequency of adverse events and a clinically relevant rate of treatment discontinuation, with no statistically significant differences between age groups. These findings support considering benznidazole in selected individuals over 50, suggesting that age alone should not prevent treatment.

Urogenital schistosomiasis caused by Schistosoma haematobium is highly endemic in the municipality of Cubal in Angola. Currently, diagnosis is based on the observation of S. haematobium eggs in urine samples by microscopy but this method has low sensitivity. Few studies have been performed using molecular techniques in high-prevalence areas for the detection of S. haematobium. The objective of this study is to evaluate the usefulness of real-time PCR as a diagnostic technique for urogenital schistosomiasis among preschool-age children and its correlation with morbidity data. A cross-sectional study was conducted in Cubal, Angola, involving 97 urine samples from preschool-age children analyzed by the dipstick test, microscopic examination of filtered urine, and real-time PCR. The diagnosis of urogenital schistosomiasis was based on microscopy and/or real-time PCR results. Clinical and ultrasonography evaluation was performed to rule out complications of schistosomiasis. We detected a total of 64.95% of samples positive by real-time PCR and 37.11% by microscopy. The sensitivity of parasitological diagnosis of urogenital schistosomiasis by real-time PCR and microscopy was 95.45% and 54.55%, respectively, and the sensitivity of real-time PCR compared with microscopy was 91.67%. A positive real-time PCR result was significantly related to older age (mean = 3.22 years), detection of eggs by microscopy, and abnormal urine dipstick results (18.56% with proteinuria, 31.96% with leukocyturia, and 31.96% with microhematuria) (p-value<0.05). Ultrasound analysis showed that 23.94% of children had urinary tract abnormalities, and it was significantly related to the real-time PCR diagnosis (p-value<0.05). Real-time PCR is a more sensitive technique than microscopy for urinary schistosomiasis diagnosis in preschool-age children in Cubal. This increase in sensitivity would allow earlier diagnosis and treatment, thus reducing the morbidity associated with schistosomiasis in its early stages.