Screening blood donors for malaria, can we increase the number of eligible donors? An observational retrospective study.

BACKGROUND: In non-endemic countries, malaria can be transmitted through blood donations from imported cases. To ensure standards of quality and safety of human blood, the European Union and Spanish national law, requires a deferral period, or a screening by immunological or genomic test among those donors with potential risk of malaria. Scientific societies, European Committee on Blood Transfusion, and Spanish Society of Haematology and Haemotherapy, refer only to the result of the immunological test. METHODS: An observational retrospective study was performed in potential donors with a positive immunological test for malaria done in the Regional Transfusion Center in Madrid and referred to the National Reference Unit for Tropical Diseases in Madrid between 2015-2020. At consultation a Polymerase Chain Reaction (PCR) for malaria was performed. RESULTS: During the study period, 121 possible donors attended for consultation at NRU-Trop. Median age: 38.5 (IQR:33-48); median time to consultation was 32 months (IQR:12.5-110). Eighty-two (67.8%) donors were migrants and thirty-nine were travellers (32.2%). ELISA values were available for 109 subjects (90.1%), 56 individual left malaria endemic area > 3 years before. All donors tested negative for Plasmodium spp PCR test (n = 121, 100%). CONCLUSIONS: None of the subjects with a positive immunologic test deferred as blood donors had a positive genomic test. The presence of Plasmodium spp in collected blood was not detected by molecular techniques. To avoid the loss of potential blood donors, especially those with low incidence red blood cell antigens, as more precise microbiology techniques become available, updating the existing legislation becomes necessary to increase the availability of donated blood.

Trends in imported infections among migrants and travellers to Spain: a decade of analysis through the +Redivi network (2012-2022).

BACKGROUND: High-speed global travel, increased trade, world population growth, migration, urbanisation and climate change have favoured the emergence and spread of pathogens. We aimed to analyse the evolution of imported infections in Spain during 2012-2022 and the potential impact of some of the abovementioned factors on differential morbidity patterns. METHODS: In this retrospective study (January/2012 to December/2022), we analysed data collected by the +Redivi network across 25 health centres. The network's standardised database records new cases of imported infections, including patient demographics, travel history, pre-travel advice and diagnostic information. To assess outcome rates over time and potential interactions, we constructed penalised weighted models to reduce the bias related to a low event rate and used weighted logistic regression for morbidity outcomes. RESULTS: We recorded 25 632 episodes, comprising 13 913 migrants, 4047 visiting friends and relatives (VFR) immigrants, 392 VFR travellers and 7280 travellers. Most immigrants came from South America (48.3%), Sub-Saharan Africa (28.5%), North Africa (6.6%), South Central Asia (5.4%) and Central America/Caribbean (5.3%). The most common regions visited by travellers were Sub-Saharan Africa (33.5%), South America (24.5%), Central America/Caribbean (13.5%), Southeast Asia (12%) and South Central Asia (10%). The proportion of diagnoses of malaria, strongyloidiasis and unspecified self-limiting febrile syndrome < 3 weeks remained unchanged during the study period. An increased frequency of diagnosis was reported for schistosomiasis, blastocystosis, giardiasis, dengue, diarrhoea, new cases of HIV, latent and pulmonary tuberculosis; a decrease was reported for syphilis, chikungunya fever, Chagas disease and eosinophilia. We detected interactions between time and sex or type of participant across the different diagnoses. CONCLUSIONS: Our study underscores the importance of epidemiological data in understanding infectious diseases dynamics among travellers and migrants, emphasising how demographic shifts, migration trends and healthcare policies affect disease profiles. Comprehensive data play an essential role in enhancing public health policies and travel advice.

Real-life application of a stratification model for HIV care.

INTRODUCTION: HIV infection has become a chronic disease with a good long-term prognosis, necessitating a change in the care model. For this study, we applied a proposal for an Optimal Care Model (OCM) for people with HIV (PHIV), which includes tools for assessing patient complexity and their classification into profiles to optimize care provision. METHODS: Observational, cross-sectional, and retrospective study. Adult PHIV treated at the Tropical Medicine consultations at Ramón y Cajal Hospital from January 1 to June 30, 2023, were included. The complexity calculation and the stratification into profiles for each patient were done according to the OCM. RESULTS: Ninety-four participants were included, 76.6% cisgender men, with a median age of 41 years (range 23-76). Latin America and Africa were the main regions of origin (72.4%). 98% had an undetectable HIV viral load. The degree of complexity was 78.7% low, 11.7% medium, 1% high, and 8.5% extreme. The predominant profile was blue (64.9%), followed by lilac (11.7%), purple (6.3%), and green (4.3%). 7.4% were unclassifiable, of whom 57.2% had high/extreme complexity. Among the unclassifiable, mental health problems were the most common. CONCLUSIONS: The OCM tools for People Living with HIV (PLWH) allow for the classification and stratification of most patients in a consultation with a non-standard population. Patients who did not fit into the pre-established profiles presented high complexity. Creating a profile focused on mental health or mixed profiles could facilitate the classification of more patients.

Travel surveillance uncovers dengue virus dynamics and introductions in the Caribbean.

Dengue is the most prevalent mosquito-borne viral disease in humans, and cases are continuing to rise globally. In particular, islands in the Caribbean have experienced more frequent outbreaks, and all four dengue virus (DENV) serotypes have been reported in the region, leading to hyperendemicity and increased rates of severe disease. However, there is significant variability regarding virus surveillance and reporting between islands, making it difficult to obtain an accurate understanding of the epidemiological patterns in the Caribbean. To investigate this, we used travel surveillance and genomic epidemiology to reconstruct outbreak dynamics, DENV serotype turnover, and patterns of spread within the region from 2009-2022. We uncovered two recent DENV-3 introductions from Asia, one of which resulted in a large outbreak in Cuba, which was previously under-reported. We also show that while outbreaks can be synchronized between islands, they are often caused by different serotypes. Our study highlights the importance of surveillance of infected travelers to provide a snapshot of local introductions and transmission in areas with limited local surveillance and suggests that the recent DENV-3 introductions may pose a major public health threat in the region.

Pulmonary infections in the returning traveler.

PURPOSE OF REVIEW: The recent COVID-19 pandemic has shaped the epidemiology of other infectious diseases globally. International tourist arrivals are increasing and recovering to prepandemic levels. This review focuses on respiratory infections in travelers, highlighting the characteristics of the main imported viral, bacterial, fungal, and parasitic infections with pulmonary involvement. RECENT FINDINGS: A recent systematic review estimated a prevalence of respiratory symptoms in travelers of around 35%, increasing to nearly 65% in the context of mass gatherings. Common viral and bacterial pathogens account for the majority of respiratory infections with an identified cause; however, recent data focus on the need for surveillance of emerging infections such as MERS-CoV, henipaviruses and multidrug resistant bacteria, which may be spread through travel. Fungal and parasitic respiratory infections are less common, and acquisition is usually associated with specific risk factors or exposure in endemic areas. Special risk groups, such as immunocompromised travelers, may be particularly vulnerable, presenting with severe disease or reactivation of latent infections. SUMMARY: The next significant international epidemic could involve another new infectious agent causing respiratory disease and spreading via mobile populations. Official protocols should be adhered to, and public health interventions implemented for effective control. Continued and globally coordinated investments in research for new vaccines, therapeutic agents, disease modeling, and digital tracking strategies are essential.

Chikungunya infection in returned travellers: results from the geosentinel network, 2005-2020.

BACKGROUND: Chikungunya is an important travel-related disease because of its rapid geographical expansion and potential for prolonged morbidity. Improved understanding of the epidemiology of travel-related chikungunya infections may influence prevention strategies including education and vaccination. METHODS: We analysed data from travellers with confirmed or probable chikungunya reported to GeoSentinel sites from 2005 to 2020. Confirmed chikungunya was defined as a compatible clinical history plus either virus isolation, positive nucleic acid test or seroconversion/rising titre in paired sera. Probable chikungunya was defined as a compatible clinical history with a single positive serology result. RESULTS: 1202 travellers (896 confirmed and 306 probable) with chikungunya were included. The median age was 43 years (range 0-91; interquartile range [IQR]: 31-55); 707 (58.8%) travellers were female. Most infections were acquired in the Caribbean (28.8%), Southeast Asia (22.8%), South Central Asia (14.2%) and South America (14.2%). The highest numbers of chikungunya cases reported to GeoSentinel were in 2014 (28.3%), 2015 (14.3%) and 2019 (11.9%). The most frequent reasons for travel were tourism (n = 592; 49.3%) and visiting friends or relatives (n = 334; 27.7%). The median time to presentation to a GeoSentinel site was 23 days (IQR: 7-52) after symptom onset. In travellers with confirmed chikungunya and no other reported illnesses, the most frequently reported symptoms included musculoskeletal symptoms (98.8%), fever/chills/sweats (68.7%) and dermatologic symptoms (35.5%). Among 917 travellers with information available, 296 (32.3%) had a pretravel consultation. CONCLUSIONS: Chikungunya was acquired by international travellers in almost 100 destinations globally. Vector precautions and vaccination where recommended should be integrated into pretravel visits for travellers going to areas with chikungunya or areas with the potential for transmission. Continued surveillance of travel-related chikungunya may help public health officials and clinicians limit the transmission of this potentially debilitating disease by defining regions where protective measures (e.g. pretravel vaccination) should be strongly considered.

Intestinal protozoa in returning travellers: a GeoSentinel analysis from 2007 to 2019.

BACKGROUND: Prolonged diarrhoea is common amongst returning travellers and is often caused by intestinal protozoa. However, the epidemiology of travel-associated illness caused by protozoal pathogens is not well described. METHODS: We analysed records of returning international travellers with illness caused by Giardia duodenalis, Cryptosporidium spp., Cyclospora cayetanensis or Cystoisospora belli, reported to the GeoSentinel Network during January 2007-December 2019. We excluded records of travellers migrating, with an unascertainable exposure country, or from GeoSentinel sites that were not located in high-income countries. RESULTS: There were 2517 cases, 82.3% giardiasis (n = 2072), 11.4% cryptosporidiosis (n = 287), 6.0% cyclosporiasis (n = 150) and 0.3% cystoisosporiasis (n = 8). Overall, most travellers were tourists (64.4%) on long trips (median durations: 18-30 days). Cryptosporidiosis more frequently affected people < 18 years (13.9%) and cyclosporiasis affected people ≥ 40 years (59.4%). Giardiasis was most frequently acquired in South Central Asia (45.8%) and sub-Saharan Africa (22.6%), cryptosporidiosis in sub-Saharan Africa (24.7%) and South-Central Asia (19.5%), cyclosporiasis in South East Asia (31.3%) and Central America (27.3%), and cystoisosporiasis in sub-Saharan Africa (62.5%). Cyclosporiasis cases were reported from countries of uncertain endemicity (e.g. Cambodia) or in countries with no previous evidence of this parasite (e.g. French Guiana). The time from symptom onset to presentation at a GeoSentinel site was the longest amongst travellers with giardiasis (median: 30 days). Over 14% of travellers with cryptosporidiosis were hospitalized. CONCLUSIONS: This analysis provides new insights into the epidemiology and clinical significance of four intestinal protozoa that can cause morbidity in international travellers. These data might help optimize pretravel advice and post-travel management of patients with travel-associated prolonged gastrointestinal illnesses. This analysis reinforces the importance of international travel-related surveillance to identify sentinel cases and areas where protozoal infections might be undetected or underreported.

Chagas Disease in Europe.

Chagas disease is currently present in many non-endemic countries and remains a neglected tropical disease globally. A review of the literature identified significant gaps and scarcity of updated information from European countries, with most studies reporting data from Spain and Italy. The index of underdiagnosis may be as high as 70%, affecting mainly females of child-bearing age. Standardized screening of fertile, non-pregnant, women from endemic countries and subsequent treatment is considered an essential strategy to control transmission and prevent new cases, yet no uniform legislation for screening risk groups exists. There is heterogeneity in Europe in terms of preventive strategies to avoid transfusion-related transmission of Chagas disease, not necessarily in line with the European directives, with some countries conducting systematic screening for T. cruzi infection in blood donors, whilst others rely on pre-transfusion questionnaires. The growing burden of the infection in resource-rich areas may provide an opportunity for progress in certain aspects of control and prevention. Options for improving screening strategies, management and linkage to care are reviewed.

Travel surveillance uncovers dengue virus dynamics and introductions in the Caribbean.

Dengue is the most prevalent mosquito-borne viral disease in humans, and cases are continuing to rise globally. In particular, islands in the Caribbean have experienced more frequent outbreaks, and all four dengue virus (DENV) serotypes have been reported in the region, leading to hyperendemicity and increased rates of severe disease. However, there is significant variability regarding virus surveillance and reporting between islands, making it difficult to obtain an accurate understanding of the epidemiological patterns in the Caribbean. To investigate this, we used travel surveillance and genomic epidemiology to reconstruct outbreak dynamics, DENV serotype turnover, and patterns of spread within the region from 2009-2022. We uncovered two recent DENV-3 introductions from Asia, one of which resulted in a large outbreak in Cuba, which was previously under-reported. We also show that while outbreaks can be synchronized between islands, they are often caused by different serotypes. Our study highlights the importance of surveillance of infected travelers to provide a snapshot of local introductions and transmission in areas with limited local surveillance and suggests that the recent DENV-3 introductions may pose a major public health threat in the region.

Chagas disease is related to structural changes of the gut microbiota in adults with chronic infection (TRIPOBIOME Study).

BACKGROUND: The implications of the gut microbial communities in the immune response against parasites and gut motility could explain the differences in clinical manifestations and treatment responses found in patients with chronic Chagas disease. METHODOLOGY/PRINCIPAL FINDINGS: In this pilot prospective cross-sectional study, we included 80 participants: 29 with indeterminate CD (ICD), 16 with cardiac CD (CCD), 15 with digestive CD (DCD), and 20 controls without CD. Stool was collected at the baseline visit and faecal microbial community structure DNA was analyzed by whole genome sequencing. We also performed a comprehensive dietary analysis. Ninety per cent (72/80) of subjects were of Bolivian origin with a median age of 47 years (IQR 39-54) and 48.3% (29/60) had received benznidazole treatment. There were no substantial differences in dietary habits between patients with CD and controls. We identified that the presence or absence of CD explained 5% of the observed microbiota variability. Subjects with CD exhibited consistent enrichment of Parabacteroides spp, while for Enterococcus hirae, Lactobacillus buchneri and Megamonas spp, the effect was less clear once excluded the outliers values. Sex, type of visceral involvement and previous treatment with benznidazole did not appear to have a confounding effect on gut microbiota structure. We also found that patients with DCD showed consistent Prevotella spp enrichment. CONCLUSIONS: We found a detectable effect of Chagas disease on overall microbiota structure with several potential disease biomarkers, which warrants further research in this field. The analysis of bacterial diversity could prove to be a viable target to improve the prognosis of this prevalent and neglected disease.

Updates on Malaria Epidemiology and Prevention Strategies.

Purpose of Review: The objective of this review was to provide an update on recent malaria epidemiology, both globally and in non-endemic areas, to identify the current distribution and repercussions of genetically diverse Plasmodium species and summarize recently implemented intervention and prevention tools. Recent Findings: Notable changes in malaria epidemiology have occurred in recent years, with an increase in the number of total cases and deaths globally during 2020-2021, in part attributed to the COVID-19 pandemic. The emergence of artemisinin-resistant species in new areas and the expanding distribution of parasites harbouring deletions of the pfhrp2/3 genes have been concerning. New strategies to curb the burden of this infection, such as vaccination, have been implemented in certain endemic areas and their performance is currently being evaluated. Summary: Inadequate control of malaria in endemic regions may have an effect on imported malaria and measures to prevent re-establishment of transmission in malaria-free areas are essential. Enhanced surveillance and investigation of Plasmodium spp. genetic variations will contribute to the successful diagnosis and treatment of malaria in future. Novel strategies for an integrated One Health approach to malaria control should also be strengthened.

Travel-associated melioidosis: a narrative review.

BACKGROUND: Melioidosis, caused by Burkholderia pseudomallei, may be considered a neglected tropical disease that remains underdiagnosed in many geographical areas. Travellers can act as the sentinels of disease activity, and data from imported cases may help complete the global map of melioidosis. METHODS: A literature search for imported melioidosis for the period 2016-22 was performed in PubMed and Google Scholar. RESULTS: In total, 137 reports of melioidosis associated with travel were identified. The majority were males (71%) and associated with exposure in Asia (77%) (mainly Thailand, 41%, and India, 9%). A minority acquired the infection in the Americas-Caribbean area (6%), Africa (5%) and Oceania (2%). The most frequent comorbidity was diabetes mellitus (25%) followed by underlying pulmonary, liver or renal disease (8, 5 and 3%, respectively). Alcohol/tobacco use were noted for seven and six patients, respectively (5%). Five patients (4%) had associated non-human immunodeficiency virus (HIV)-related immunosuppression, and three patients (2%) had HIV infection. One patient (0.8%) had concomitant coronavirus disease 19. A proportion (27%) had no underlying diseases. The most frequent clinical presentations included pneumonia (35%), sepsis (30%) and skin/soft tissue infections (14%). Most developed symptoms <1 week after return (55%), and 29% developed symptoms >12 weeks after. Ceftazidime and meropenem were the main treatments used during the intensive intravenous phase (52 and 41% of patients, respectively) and the majority (82%) received co-trimoxazole alone/combination, for the eradication phase. Most patients had a favourable outcome/survived (87%). The search also retrieved cases in imported animals or cases secondary to imported commercial products. CONCLUSIONS: As post-pandemic travel soars, health professionals should be aware of the possibility of imported melioidosis with its diverse presentations. Currently, no licensed vaccine is available, so prevention in travellers should focus on protective measures (avoiding contact with soil/stagnant water in endemic areas). Biological samples from suspected cases require processing in biosafety level 3 facilities.

Dengue outbreak amongst travellers returning from Cuba-GeoSentinel surveillance network, January-September 2022.

Increasing numbers of travellers returning from Cuba with dengue virus infection were reported to the GeoSentinel Network from June to September 2022, reflecting an ongoing local outbreak. This report demonstrates the importance of travellers as sentinels of arboviral outbreaks and highlights the need for early identification of travel-related dengue.

Screening of imported malaria infection in asymptomatic migrants from Sub-Saharan Africa: A retrospective analysis of a 2010-2019 cohort.

BACKGROUND: Up to 40% of cases of imported malaria in Europe are diagnosed in recently arrived migrants, who generally exhibit asymptomatic or mild symptoms and show low parasitaemia (submicroscopic). The study describes the prevalence of malaria infection among asymptomatic Sub-Saharan African migrants (ASSAM) and compares asymptomatic malaria-infected (AMI) vs non-malaria infected patients. METHODS: An observational, comparative, retrospective study was carried out in ASSAM who underwent a medical examination, between 2010 and 2019 at the National Reference Unit for Tropical Diseases (NRU-Trop) in Madrid, Spain. Medical examination and systematic screening protocol for infectious diseases, including screening for malaria infection by Polymerase Chain Reaction (PCR) was performed. RESULTS: During the study period, 632 out of 1061 ASSAM were screened for malaria, median age: 24 years (IQR:1-5); median time from arrival to diagnosis: 2 months (IQR:1-5). P. falciparum was the most frequent species: 61 patients (67.8%). Compared to non-malaria infected, AMI subjects had: higher rate of co-infection with S. stercoralis (41.1%VS 22.9%;p < 0.001) and filariae (8.9% VS 2.4%;p = 0.006), lower erythrocyte corpuscular volume (83.6 VS 84.4;p = 0.008) and lower levels of cholesterol (151.0 VS 167.3;p < 0.001). CONCLUSIONS: We observed a high prevalence of AMI among ASSAM. This highlights the need to consider routing screening of migrants from endemic areas and to study if such screening could avoid the potential morbidities associated with chronic infection, reduce morbi-mortality of acute malaria and the risk of transmission in host communities.