Malaria screening: what is the contribution of molecular biology?

INTRODUCTION: According to the World Health Organization, Microscopy is the gold standard for diagnosing malaria. However, the performance of this examination depends on the experience of the microscopist and the level of parasitemia. Thus, molecular biology detection of malaria could be an alternative technique. AIM: evaluate the contribution of molecular biology in detecting imported malaria. METHODS: This was a descriptive, prospective study, including all students, from the Monastir region, and foreigners, from countries endemic to malaria. The study period was from September 2020 to April 2021. Each subject was screened for malaria by three methods: direct microscopic detection of Plasmodium, detection of plasmodial antigens, and detection of plasmodial DNA by nested PCR. RESULTS: Among the 127 subjects screened, only one had a positive microscopic examination for Plasmodium falciparum. Among the 126 subjects with a negative microscopic examination, twelve students had a positive nested PCR result, i.e. 9.5%. Molecular sequencing allowed the identification of ten isolates of Plasmodium falciparum, one Plasmodium malariae and one Plasmodium ovale. Our study showed that the results of nested PCR agreed with those of microscopy in 90.6% of cases. CONCLUSION: Nested PCR seems more sensitive for the detection of low parasitemias. Hence the importance of including molecular biology as a malaria screening tool to ensure better detection of imported cases.

Emergence of imported cutaneous leishmaniasis caused by Leishmania major: a case series from Kerala, India.

Cutaneous leishmaniasis (CL) is often considered a 'great imitator' and is the most common form of leishmaniasis. The Leishmania species responsible for CL varies among countries, as these species exhibit specific distribution patterns. The increased mobility of people across countries has resulted in the imported incidences of leishmaniasis caused by non-endemic species of Leishmania. During 2023, we confirmed three CL cases caused by L. major from Kerala, India, and upon detailed investigation, these were identified to be imported from the Middle East and Kazakhstan regions. This is the first report of CL caused by L. major from Kerala. The lesion morphology, detection of anti-rK 39 antibody and Leishmania parasite DNA from the blood samples were the unique observations of these cases. Kerala, being an emerging endemic zone of visceral leishmaniasis (VL) and CL, the imported incidences of leishmaniasis by non-endemic species can pose a significant threat, potentially initiating new transmission cycles of leishmaniasis caused by non-endemic species.

American Cutaneous Leishmaniasis: Imported cases in Berlin 2000-2023.

BACKGROUND: American Cutaneous Leishmaniasis (ACL) shows variable response to therapy, but data on species-specific treatment efficacy is scarce. We describe the clinical characteristics and outcome of patients with ACL imported to a tertiary centre in Germany and determine whether species-specific therapy according to the 2014 "LeishMan" group recommendations is associated with cure. METHODS: A retrospective chart review was conducted at the Charité Institute of International Health in Berlin. We analysed data on PCR-confirmed ACL cases collected between 2000 and 2023. Systemic therapy included liposomal amphotericin B, miltefosine, pentavalent antimony, ketoconazole or itraconazole. Localized therapy included perilesional pentavalent antimony or paromomycin ointment. Cure was defined as re-epithelialization of ulcers or disappearance of papular-nodular lesions after 3 months of treatment. Logistic regression models were used to quantify the effect of species-specific systemic therapy on the outcome. RESULTS: 75 cases were analysed. Most patients were male (62%), median age was 35 years, no patient had a history of immunosuppression. The most common reason for travel was tourism (60%), the most common destination was Costa Rica (28%), the median duration of illness was 8 weeks, and most patients presented with ulcers (87%). Lesions were complex in 43%. The most common Leishmania (L.) species was L. braziliensis (28%), followed by L. panamensis (21%). 51/73 (70%) patients were cured after initial therapy and 17/21 (81%) after secondary therapy. Cure after systemic therapy was more frequent when species-specific treatment recommendations were followed (33/45; 73%), compared to when not followed, (6/17; 35%, P = 0.008). This association was independent of age, sex, previous therapy, complex lesions, and Leishmania species (adjusted OR, 5.06; 95% CI, 1.22-24.16). CONCLUSIONS: ACL is a rare, imported disease in Germany. Complex lesions were common, challenging successful therapy. This study highlights the importance of identifying the parasite species and suggests that a species-specific approach to treatment leads to better outcomes.

Imported schistosomiasis in travelers: Experience from a referral tropical medicine unit in Barcelona, Spain.

BACKGROUND: Acute schistosomiasis occurs most often in travelers to endemic regions. The aim of the study is to describe the epidemiological, clinical and parasitological characteristics of patients with schistosomiasis acquired during an international travel. METHODS: Observational retrospective study including all travel-related schistosomiasis cases seen at the International Health Unit Vall d'Hebron-Drassanes (Barcelona, Spain) from 2009 to 2022. Diagnosis of schistosomiasis was defined by the presence of Schistosoma eggs in stools or urine or the positivity of a serological test. We collected demographic, epidemiological, clinical, parasitological, and therapeutic information. RESULTS: 917 cases of schistosomiasis were diagnosed, from whom 96 (10.5 %) were travel-related. Mean age of the patients was 34.9 years, and 53.1 % were women. Median duration of the travel was 72 days, and geographical areas where travelers had contact with fresh water were Africa (82.3 %), Asia (12.5 %), and South America (5.2 %). Twenty (20.8 %) patients reported having had some clinical symptom, being gastrointestinal symptoms the most frequent. Two patients developed the classical Katayama syndrome. In eleven (11.5 %) cases eggs were observed in urine or feces samples, and 85 (88.5 %) cases were diagnosed by a positive serology. Ninety-one (94.8 %) patients received treatment with praziquantel with different therapeutic schemes. The two patients with Katayama syndrome received concomitant treatment with corticosteroids. CONCLUSIONS: Schistosomiasis in travelers represented 10 % of the overall schistosomiasis cases in our center. Increasing the awareness in the pre-travel advice and implementing specific screening in those travelers at risk (long travelers, contact with fresh water) could reduce the incidence and associated morbidity in this group.

The prevalence of malaria in the five districts of Limpopo Province, South Africa, 2015 - 2017.

BACKGROUND: In South Africa (SA), malaria is endemic in three of nine provinces - KwaZulu-Natal, Mpumalanga and Limpopo. During 2010 - 2014, SA reported that ~47.6% of all malaria cases were imported. Contemporary estimates for the prevalence of malaria in the five districts of Limpopo Province are limited, with unknown proportions of imported malaria cases. We estimated the prevalence of malaria, and the proportion of imported malaria cases in the five districts of Limpopo, from January 2015 to December 2017. OBJECTIVE: To measure the prevalence of malaria in Limpopo Province, the proportion of malaria cases that are imported and to determine factors associated with malaria from January 2015 to December 2017. METHODS: We retrospectively reviewed data routinely collected through the Malaria Information System and Laboratory Information System of the National Health Laboratory Services, and assessed associations with age, sex and district, using a multivariable logistic regression model. RESULTS: From 2015 to 2017, a total of 43 199 malaria cases were reported, of which 3.5% (n=1 532) were imported. The prevalence of malaria in Limpopo Province was the highest in 2017, at 331.0 per 100 000 population. The highest malaria prevalence district was Vhembe, with 647.9 in 2015, 220.3 in 2016 and 659.4 in 2017 per 100 000 population. However, Waterberg had the highest proportion of imported malaria cases 28.5% (437/1 532). In adjusted analyses, ages 15 - 49 years (adjusted odds ratio (aOR) 1.58, 95% confidence interval (CI) 1.48 - 1.68, p<0.001) and <1 year (aOR 1.55, 95% CI 1.37 - 0.74, p<0.001) were at higher odds of having malaria compared with ages ≥65 years. CONCLUSION: These findings highlight the significant burden of imported malaria in Limpopo Province. There is a need for strengthened surveillance and control programmes in neighboring countries (such as Mozambique, Zimbabwe and Botswana) to reduce the importation and spread of malaria in this region.

Clinical and epidemiological features of imported loiasis in Beijing: a report from patients returned from Africa.

BACKGROUND: Loiasis is one of the significant filarial diseases for people living in West and Central Africa with wide endemic area but is not seen in China. As economy booms and international traveling increase, China faces more and more imported parasitic diseases that are not endemic locally. Loiasis is one of the parasitic diseases that enter China by travelers infected in Africa. The better understanding of the clinical and laboratory features of loa loa infection will facilitate the diagnosis and treatment of loiasis in China. METHODS: The study targeted travelers who were infected with L. loa in endemic Africa regions and returned to Beijing between 2014 and 2023. Epidemiological, clinical, and biological data as well as treatment of these patients were collected. RESULTS: Total 21 cases were identified as L. loa infection based on their typical clinical manifestations and parasite finding. All cases had a history of travel to Africa for more than 6 months, most of them are the construction workers dispatched to West Africa with outdoor activities. Calabar swelling (n = 19; 90.5%) and pruritus (n = 11; 52.4%) were among the most common clinical symptoms followed by muscle pain (n = 7; 33.3%) and skin rash (n = 2; 9.5%). The adult worms were observed in the eyelid or subconjunctiva (n = 2; 9.5%) and subcutaneous tissues (n = 2; 9.5%). Although all patients presented with a high eosinophil count (> 0.52 × 109/L), only two cases displayed microfilariae in fresh venous blood and positive for filarial antigen. A cut section of adult worm was observed through biopsy on a skin nodule surrounded by lymphocytes, plasma cells and eosinophils. All subjects were positive in PCR targeting L. loa ITS-1. The constructed phylogenetic tree based on the amplified ITS-1 sequences identified their genetical relation to the L. Loa from Africa. All patients treated with albendazole and diethylcarbamazine were recovered without relapse. CONCLUSION: This study provides useful information and guideline for physicians and researchers in non-endemic countries to diagnose and treat loiasis and L. loa infections acquired from endemic regions.

A system dynamics modelling and analytical framework for imported dengue outbreak surveillance and risk mapping.

System Dynamics (SD) models have been used to understand complex, multi-faceted dengue transmission dynamics, but a gap persists between research and actionable public health tools for decision-making. Spain is an at-risk country of imported dengue outbreaks, but only qualitative assessments are available to guide public health action and control. We propose a modular SD model combining temperature-dependent vector population, transmission parameters, and epidemiological interactions to simulate outbreaks from imported cases accounting for heterogeneous local climate-related transmission patterns. Under our assumptions, 15 provinces sustain vector populations capable of generating outbreaks from imported cases, with heterogeneous risk profiles regarding seasonality, magnitude and risk window shifting from late Spring to early Autum. Results being relative to given vector-to-human populations allow flexibility when translating outcomes between geographic scales. The model and the framework are meant to serve public health by incorporating transmission dynamics and quantitative-qualitative input to the evidence-based decision-making chain. It is a flexible tool that can easily adapt to changing contexts, parametrizations and epidemiological settings thanks to the modular approach.

Spatiotemporal analysis of imported and local dengue virus and cases in a metropolis in Southwestern China, 2013-2022.

Dengue fever is a viral illness, mainly transmitted by Aedes aegypti and Aedes albopictus. With climate change and urbanisation, more urbanised areas are becoming suitable for the survival and reproduction of dengue vector, consequently are becoming suitable for dengue transmission in China. Chongqing, a metropolis in southwestern China, has recently been hit by imported and local dengue fever, experiencing its first local outbreak in 2019. However, the genetic evolution dynamics of dengue viruses and the spatiotemporal patterns of imported and local dengue cases have not yet been elucidated. Hence, this study implemented phylogenetic analyses using genomic data of dengue viruses in 2019 and 2023 and a spatiotemporal analysis of dengue cases collected from 2013 to 2022. We sequenced a total of 15 nucleotide sequences of E genes. The dengue viruses formed separate clusters and were genetically related to those from Guangdong Province, China, and countries in Southeast Asia, including Laos, Thailand, Myanmar and Cambodia. Chongqing experienced a dengue outbreak in 2019 when 168 imported and 1,243 local cases were reported, mainly in September and October. Few cases were reported in 2013-2018, and only six were imported from 2020 to 2022 due to the COVID-19 lockdowns. Our findings suggest that dengue prevention in Chongqing should focus on domestic and overseas population mobility, especially in the Yubei and Wanzhou districts, where airports and railway stations are located, and the period between August and October when dengue outbreaks occur in endemic regions. Moreover, continuous vector monitoring should be implemented, especially during August-October, which would be useful for controlling the Aedes mosquitoes. This study is significant for defining Chongqing's appropriate dengue prevention and control strategies.

An epidemiological analysis of severe imported malaria infections in Sri Lanka, after malaria elimination.

BACKGROUND: Imported malaria continues to be reported in Sri Lanka after it was eliminated in 2012, and a few progress to life-threatening severe malaria. METHODS: Data on imported malaria cases reported in Sri Lanka from 2013 to 2023 were extracted from the national malaria database maintained by the Anti Malaria Campaign (AMC) of Sri Lanka. Case data of severe malaria as defined by the World Health Organization were analysed with regard to patients' general characteristics and their health-seeking behaviour, and the latter compared with that of uncomplicated malaria patients. Details of the last three cases of severe malaria in 2023 are presented. RESULTS: 532 imported malaria cases were diagnosed over 11 years (2013-2023); 46 (8.6%) were severe malaria, of which 45 were Plasmodium falciparum and one Plasmodium vivax. Most severe malaria infections were acquired in Africa. All but one were males, and a majority (87%) were 26-60 years of age. They were mainly Sri Lankan nationals (82.6%). Just over half (56.5%) were treated at government hospitals. The average time between arrival of the person in Sri Lanka and onset of illness was 4 days. 29 cases of severe malaria were compared with 165 uncomplicated malaria cases reported from 2015 to 2023. On average both severe and uncomplicated malaria patients consulted a physician equally early (mean = 1 day) with 93.3% of severe malaria doing so within 3 days. However, the time from the point of consulting a physician to diagnosis of malaria was significantly longer (median 4 days) in severe malaria patients compared to uncomplicated patients (median 1 day) (p = 0.012) as was the time from onset of illness to diagnosis (p = 0.042). All severe patients recovered without sequelae except for one who died. CONCLUSIONS: The risk of severe malaria among imported cases increases significantly beyond 5 days from the onset of symptoms. Although patients consult a physician early, malaria diagnosis tends to be delayed by physicians because it is now a rare disease. Good access to expert clinical care has maintained case fatality rates of severe malaria at par with those reported elsewhere.

Modeling the Regional Distribution of International Travelers in Spain to Estimate Imported Cases of Dengue and Malaria: Statistical Inference and Validation Study.

BACKGROUND: Understanding the patterns of disease importation through international travel is paramount for effective public health interventions and global disease surveillance. While global airline network data have been used to assist in outbreak prevention and effective preparedness, accurately estimating how these imported cases disseminate locally in receiving countries remains a challenge. OBJECTIVE: This study aimed to describe and understand the regional distribution of imported cases of dengue and malaria upon arrival in Spain via air travel. METHODS: We have proposed a method to describe the regional distribution of imported cases of dengue and malaria based on the computation of the "travelers' index" from readily available socioeconomic data. We combined indicators representing the main drivers for international travel, including tourism, economy, and visits to friends and relatives, to measure the relative appeal of each region in the importing country for travelers. We validated the resulting estimates by comparing them with the reported cases of malaria and dengue in Spain from 2015 to 2019. We also assessed which motivation provided more accurate estimates for imported cases of both diseases. RESULTS: The estimates provided by the best fitted model showed high correlation with notified cases of malaria (0.94) and dengue (0.87), with economic motivation being the most relevant for imported cases of malaria and visits to friends and relatives being the most relevant for imported cases of dengue. CONCLUSIONS: Factual descriptions of the local movement of international travelers may substantially enhance the design of cost-effective prevention policies and control strategies, and essentially contribute to decision-support systems. Our approach contributes in this direction by providing a reliable estimate of the number of imported cases of nonendemic diseases, which could be generalized to other applications. Realistic risk assessments will be obtained by combining this regional predictor with the observed local distribution of vectors.

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, urbanization 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 penalized 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, whereas 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, emphasizing 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.

Modeling the effect of imported malaria on the elimination programme in KwaZulu-Natal province of South Africa.

Introduction: with imported malaria cases in a given population, the question arises as to what extent the local cases are a consequence of the imports or not. We perform a modeling analysis for a specific area, in a region aspiring for malaria-free status. Methods: data on malaria cases over ten years is subjected to a compartmental model which is assumed to be operating close to the equilibrium state. Two of the parameters of the model are fitted to the decadal data. The other parameters in the model are sourced from the literature. The model is utilized to simulate the malaria prevalence with or without imported cases. Results: in any given year the annual average of 460 imported cases, resulted in an end-of-year season malaria prevalence of 257 local active infectious cases, whereas without the imports the malaria prevalence at the end of the season would have been fewer than 10 active infectious cases. We calculate the numerical value of the basic reproduction number for the model, which reveals the extent to which the disease is being eliminated from the population or not. Conclusion: without the imported cases, over the ten seasons of malaria, 2008-2018, the KwaZulu-Natal province would have been malaria-free over at least the last 7 years of the decade indicated. This simple methodology works well even in situations where data is limited.

Autochthonous and imported giardiasis cases: An analysis of two decades of national surveillance data, Germany, 2002 to 2021.

BackgroundGiardia duodenalis is a major cause of gastroenteritis globally, and is the most common food- and waterborne parasitic infection in Europe.AimTo describe the epidemiology of reported acute giardiasis cases in Germany and compare demographic and clinical characteristics between imported and autochthonous cases.MethodsWe conducted a descriptive analysis of giardiasis cases that fulfilled the national case definition and were reported between January 2002 and December 2021. We defined an imported case as having at least one place of exposure abroad in the 3-25 days before symptom onset. We analysed case numbers and incidence by age, sex, month reported and geographic region, both overall and stratified by autochthonous and imported cases.ResultsFrom 2002 to 2021, 72,318 giardiasis cases were reported in Germany, corresponding to a mean annual incidence of 4.4 per 100,000 population. Annual incidence gradually decreased since 2013, declining sharply during the COVID-19 pandemic in 2020-21. Of 69,345 cases reported between 2002 and 2019, 35% were imported. Incidence of autochthonous cases (overall yearly mean: 3.1/100,000) was highest in males and young children (< 5 years); imported cases were predominantly adults aged 20-39 years. We identified seasonal patterns for imported and autochthonous cases.ConclusionsGiardiasis in Germany is typically assumed to be imported. Our data, however, underline the importance of autochthonous giardiasis. Travel advice might reduce imported infections, but prevention strategies for autochthonous infections are less clear. Dietary, behavioural and environmental risk factors need to be further investigated to enhance infection prevention measures for autochthonous giardiasis.

Notes from the Field: Increases in Imported Malaria Cases - Three Southern U.S. Border Jurisdictions, 2023.

Malaria is a severe and potentially fatal mosquitoborne disease caused by infection with Plasmodium spp. parasites. Although malaria is no longer endemic in the United States, imported infections are reported annually; the primary risk group has been U.S. residents traveling to areas where malaria is endemic (1). In 2023, sporadic locally acquired mosquito-transmitted malaria cases were reported in several U.S. states (2,3). This report describes increases in imported malaria cases in 2023 compared with 2022 in three public health jurisdictions along the U.S. southern border.

Pregnancy outcomes in women with imported malaria in mainland France: A retrospective study from 2004 to 2014.

OBJECTIVES: There is little data on pregnant women with imported malaria in high-income countries, especially regarding offspring outcomes. We wanted to determine pregnancy outcomes of imported malaria in pregnant women in mainland France. PATIENTS AND METHODS: We conducted a retrospective, descriptive study of outcomes in pregnant women hospitalized with malaria from 2004 to 2014 in two regions of mainland France. An adverse outcome was defined as a miscarriage, stillbirth, preterm birth (<35 weeks of gestation), low birth weight (LBW) defined as less than 2500 g, or congenital malaria. RESULTS: Of 60 pregnancies, 5 were excluded because of elective abortions; 55 were investigated, of which 11 were primigravidae and 44 multigravidae. Pregnancies were singleton (n = 51) or twin (n = 4). Mean age was 30.4 years (range:19-45 y). Among the 55 cases, 9 ended in a miscarriage (8 singletons and 1 twin pregnancy) and 1 had a stillbirth at 21 weeks of gestation, all immediately after the malarial episode. 45 gave birth (29 vaginal deliveries and 16 caesarean sections) to 48 (42 singletons and 6 twins) newborns. Amongst these, 30 were healthy full-term newborns, 10 had LBW, and 8 were preterm. Overall, 26 of 55 (47.3%) pregnancies, and 29 of 59 (49.2%) offsprings had adverse outcomes. Compared to singleton pregnancies, twin pregnancies were associated with adverse outcomes (p = 0.0438). CONCLUSIONS: Imported malaria has a severe impact on pregnancy outcomes. Prevention and management of imported malaria in pregnancy should be optimized.

Modelling the spatial risk of malaria through probability distribution of Anopheles maculipennis s.l. and imported cases.

Malaria remains one of the most important infectious diseases globally due to its high incidence and mortality rates. The influx of infected cases from endemic to non-endemic malaria regions like Europe has resulted in a public health concern over sporadic local outbreaks. This is facilitated by the continued presence of competent Anopheles vectors in non-endemic countries.We modelled the potential distribution of the main malaria vector across Spain using the ensemble of eight modelling techniques based on environmental parameters and the Anopheles maculipennis s.l. presence/absence data collected from 2000 to 2020. We then combined this map with the number of imported malaria cases in each municipality to detect the geographic hot spots with a higher risk of local malaria transmission.The malaria vector occurred preferentially in irrigated lands characterized by warm climate conditions and moderate annual precipitation. Some areas surrounding irrigated lands in northern Spain (e.g. Zaragoza, Logroño), mainland areas (e.g. Madrid, Toledo) and in the South (e.g. Huelva), presented a significant likelihood of A. maculipennis s.l. occurrence, with a large overlap with the presence of imported cases of malaria.While the risk of malaria re-emergence in Spain is low, it is not evenly distributed throughout the country. The four recorded local cases of mosquito-borne transmission occurred in areas with a high overlap of imported cases and mosquito presence. Integrating mosquito distribution with human incidence cases provides an effective tool for the quantification of large-scale geographic variation in transmission risk and pinpointing priority areas for targeted surveillance and prevention.

Imported infectious diseases in migrants from Latin America: A retrospective study from a referral centre for tropical diseases in Spain, 2017-2022.

INTRODUCTION: Detecting imported diseases by migrants and individuals visiting friends and relatives (VFR) is key in the prevention and management of emergent infectious diseases acquired abroad. METHODS: Retrospective descriptive study on migrants and VFR from Central and South America between 2017 and 2022 attended at a National Referral Centre for Tropical Diseases in Madrid, Spain. Demographic characteristics, syndromes and confirmed travel-related diagnoses were obtained from hospital patient medical records. RESULTS: 1654 cases were registered, median age of 42 years, 69.1% were female, and 55.2% were migrants. Most cases came from Bolivia (49.6%), followed by Ecuador (12.9%). Health screening while asymptomatic (31.6%) was the main reason for consultation, followed by Chagas disease follow-up (31%). Of those asymptomatic at screening, 47,2% were finally diagnosed of any disease, mainly Chagas disease (19,7%) and strongyloidiasis (10,2%) CONCLUSION: Our study emphasizes the importance of proactive health screening to detect asymptomatic conditions in migrants and VFR, enabling timely intervention and improved health outcomes. By understanding the unique health profiles of immigrant populations, targeted public health interventions can be devised to safeguard the well-being of these vulnerable groups.

Infections diagnosed in children and young people screened for malaria in UK emergency departments: a retrospective multi-centre study.

BACKGROUND: Data on imported infections in children and young people (CYP) are sparse. AIMS: To describe imported infections in CYP arriving from malaria-endemic areas and presenting to UK emergency departments (ED) who were screened for malaria. METHODS: This is a retrospective, multi-centre, observational study nested in a diagnostic accuracy study for malaria rapid diagnostic tests. Any CYP < 16 years presenting to a participating ED with a history of fever and travel to a malaria-endemic area between 1 January 2016 and 31 December 2017 and who had a malaria screen as a part of standard care were included. Geographical risk was calculated for the most common tropical infections. RESULTS: Of the 1414 CYP screened for malaria, 44.0% (n = 622) arrived from South Asia and 33.3% (n = 471) from sub-Saharan Africa. Half (50.0%) had infections common in both tropical and non-tropical settings such as viral upper respiratory tract infection (URTI); 21.0% of infections were coded as tropical if gastro-enteritis is included, with a total of 4.2% (60) cases of malaria. CYP diagnosed with malaria were 7.44 times more likely to have arrived from sub-Saharan Africa than from South Asia (OR 7.44, 3.78-16.41). CONCLUSION: A fifth of CYP presenting to participating UK EDs with fever and a history of travel to a malaria-endemic area and who were screened for malaria had a tropical infection if diarrhoea is included. A third of CYP had no diagnosis. CYP arriving from sub-Saharan Africa had the greatest risk of malaria.Abbreviations: CYP: children and young people; ED: emergency department; PERUKI: Paediatric Emergency Research in the UK and Ireland; RDT: rapid diagnostic test; VFR: visiting friends and relatives.

Epidemiologic Trends and Distributions of Imported Infectious Diseases Among Travelers to Japan Before and During the COVID-19 Pandemic, 2016 to 2021: A Descriptive Study.

BACKGROUND: Little is known about the trends of imported infectious diseases among travelers to non-endemic countries during the novel coronavirus disease 2019 (COVID-19) pandemic. This article aimed to describe those among travelers to Japan. METHODS: This is a descriptive study based on national surveillance data. Imported infectious disease cases were defined as those with a reported overseas source of infection among 15 diseases pre-selected based on the probability and impact of importation. The number of notified cases from April 2016 to March 2021 were described by disease and time of diagnosis. The relative ratio and absolute difference in case counts-both by number and per arrival-were calculated by disease comparing those from the pandemic period (April 2020-March 2021) to the pre-pandemic period (April 2016-March 2020). RESULTS: A total of 3,524 imported infectious disease cases were diagnosed during the study period, including 3,439 cases before and 85 cases during the pandemic. The proportionate distribution of diseases changed but notification counts of all 15 diseases decreased during the pandemic. Accounting for arrivals, however, seven diseases showed a two-fold or greater increase, with a notable absolute increase per million arrivals for amebiasis (60.1; 95% confidence interval [CI], 41.5-78.7), malaria (21.7; 95% CI, 10.5-33.0), and typhoid fever (9.3; 95% CI, 1.9-16.8). CONCLUSION: The epidemiology of imported infectious diseases changed during the pandemic. While the number of imported infectious disease cases decreased, the number of cases per arrivals increased considerably both in relative and absolute terms for several diseases of public health and clinical importance.