[Epidemiological characteristics of imported malaria after malaria elimination in Shanxi Province, 2019-2023].

Objective: To analyze the epidemiological characteristics of imported malaria cases from 2019 to 2023 after the elimination of malaria in Shanxi Province, and provide reference for formulating scientific and effective malaria prevention and control strategies in Shanxi Province. Methods: The data of imported malaria cases were collected China Information System for Disease Control and Prevention and National Parasitic Disease Control Information Management System in Shanxi Province, from 2019-2023. Descriptive epidemiological method and SPSS 26.0 statistical software were used for descriptive epidemiological statistical analysis. Results: A total of 51 malaria cases were reported in Shanxi Province in 2019-2023, all imported from abroad. Among them, there were 38 cases of falciparum malaria (74.51%), 6 cases of plasmodium ovale (11.77%), 5 cases of plasmodium vivax (9.80%), 1 case of plasmodium triticum malaria (1.96%), and 1 case of mixed infections (1.96%), with nodeaths; cases were predominantly males (94.12%, 48/51) and workers who went abroad for work (84.31%,43/51); the median age of onset was 37 years old; and there were imported cases every month, with no obvious peak of incidence; Taiyuan City reported the most cases, accounting for 72.55% (37/51) of the total number of cases,the source of infection of cases was mainly from Africa (96.08%), with the Democratic Republic of the Congo (16 cases), Nigeria (6 cases), Equatorial Guinea (5 cases), Mozambique (3 cases), and Republic of the Congo (3 cases) in that order; the median time between the onset of disease and first diagnosis, and the median time between first diagnosis and confirmation, were two times longer than that of first diagnosis, and the median time between first diagnosis and confirmation was two times longer than that of first diagnosis. The M(Q1, Q3) intervals from onset to first diagnosis and from first diagnosis to confirmed diagnosis were 2(0,4) days and 1(0,3) days, respectively, with statistically significant differences between different years from onset to first diagnosis (H=17.41, P=0.048), and from first diagnosis to confirmed diagnosis (H=20.82, P=0.010). A total of 101 146 blood tests for febrile patients were conducted in the province during the five years, with the minimum number of blood tests in 2020 (19 867 person-times) and the maximum number of blood tests in 2023 (20 778 person-times). Conclusions: After the elimination of malaria in Shanxi Province from 2019 to 2023, all malaria cases were imported from abroad, and it is still necessary to strengthen the surveillance of people traveling to and from malaria-endemic areas, implement the combination of medical treatment and prevention, and jointly prevent and control the occurrence of imported malaria.

Virulence of Burkholderia pseudomallei ATS2021 Unintentionally Imported to United States in Aromatherapy Spray.

In the United States in 2021, an outbreak of 4 cases of Burkholderia pseudomallei, the etiologic agent of melioidosis and a Tier One Select Agent (potential for deliberate misuse and subsequent harm), resulted in 2 deaths. The causative strain, B. pseudomallei ATS2021, was unintentionally imported into the United States in an aromatherapy spray manufactured in India. We established that ATS2021 represents a virulent strain of B. pseudomallei capable of robust formation of biofilm at physiologic temperatures that may contribute to virulence. By using mouse melioidosis models, we determined median lethal dose estimates and analyzed the bacteriologic and histopathologic characteristics of the organism, particularly the potential neurologic pathogenesis that is probably associated with the bimABm allele identified in B. pseudomallei strain ATS2021. Our data, combined with previous case reports and the identification of endemic B. pseudomallei strains in Mississippi, support the concept that melioidosis is emerging in the United States.

[Epidemiological characteristics and diagnosis of imported Plasmodium malariae and Plasmodium ovale malaria cases in five provinces of China from 2014 to 2021].

OBJECTIVE: To investigate the epidemiological characteristics and diagnosis of imported Plasmodium malariae and P. ovale malaria cases in Anhui Province, Hubei Province, Zhejiang Province, Guangxi Zhuang Autonomous Region and Henan Province from 2014 to 2021, so as to provide insights into malaria control in these five provinces. METHODS: All data pertaining to malaria cases reported in five provinces of China were captured from Chinese Disease Control and Prevention Information System from 2014 to 2021, and the epidemiological characteristics of imported P. malariae and P. ovale malaria cases were analysed using a descriptive epidemiological method. The duration from onset of malaria to initial diagnosis, duration from initial diagnosis to definitive diagnosis, institutions of initial and definitive diagnoses, and proportion of correct malaria diagnosis at initial diagnosis were statistically analyzed. RESULTS: A total of 1 223 imported P. malariae and P. ovale malaria cases were reported in Anhui Province, Hubei Province, Zhejiang Province, Henan Province and Guangxi Zhuang Autonomous Region from 2014 to 2021, there were 158 P. malariae malaria cases (12.92%) and 1 065 P. ovale malaria cases (87.08%). Totally 98.53% (1 205/1 223) of the imported malaria cases were from Africa, with Angola (18.99%, 30/158), Nigeria (11.39%,18/158), Cameroon (10.76%, 17/158), Ghana (10.13%, 16/158) and the Democratic Republic of the Congo (10.13%,16/158) as predominant countries where P. malariae malaria cases were from, and Ghana (23.19%, 247/1 065), Cameroon (14.74%, 157/1 065), Nigeria (9.39%, 100/1 065) and Angola (6.95%, 74/1 065) as predominant countries where P. ovale malaria cases were from. There were significant differences in the duration from onset of malaria to initial diagnosis (χ2 = 27.673, P = 0.000) and duration from initial diagnosis to definitive diagnosis of P. malariae and P. ovale malaria cases (χ2 = 29.808, P = 0.000), and the proportions of correct initial diagnosis of P. malariae and P. ovale malaria cases were 38.61% (61/158) and 56.53% (602/1 065). There were 74.69% (118/158) of P. malariae malaria cases with definitive diagnosis in county-, city-, and province-level medical institutions, and 79.25% (844/1 065) of P. ovale malaria cases with definitive diagnosis in county- and city-level medical institutions and county-level centers for disease control and prevention. CONCLUSIONS: The imported P. malariae and P. ovale malaria cases in Anhui Province, Hubei Province, Zhejiang Province, Henan Province and Guangxi Zhuang Autonomous Region from 2014 to 2021 were mainly returned from Africa and the proportion of correct diagnosis of P. malariae and P. ovale malaria was low at initial diagnosis. Persistent improvements in the diagnostic capability of malaria are required in medical institutions.

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.

Profile and Determinants for Complications of Imported Malaria in 5 Chinese Provinces From 2014 to 2021: Retrospective Analysis.

Background: In 2021, the World Health Organization officially declared the People's Republic of China as malaria-free. However, despite this milestone achievement, the continued occurrence of severe and fatal cases of imported malaria in China, due to globalization and increased international communication, remains a significant public health concern. Objective: The aim of this study was to elucidate the epidemiological characteristics of imported malaria in 5 Chinese provinces from 2014 to 2021 and to identify the factors that influence complications in imported malaria cases. The findings will provide a basis for enhancing prevention and control measures, thereby consolidating China's achievements in malaria elimination. Methods: A case-based retrospective study was performed, using surveillance data collected from the representative provinces of China from 2014 to 2021. Epidemiological characteristics were analyzed using descriptive statistics. Logistic regression was used to identify the factors influencing the occurrence of complications. Results: A total of 5559 malaria cases were included during the study period. The predominant species was Plasmodium falciparum (3940/5559, 70.9%), followed by Plasmodium ovale (1054/5559, 19%), Plasmodium vivax (407/5559, 7.3%), Plasmodium malariae (157/5559, 2.8%), and 1 case of Plasmodium knowlesi. Most of the cases were male (5343/5559, 96.1%). The complication rates for P falciparum and P ovale were 11.4% and 3.3%, respectively. Multivariate logistic regression analysis of the relevant factors of malaria complications revealed potential protective factors, including a previous infection by Plasmodium (P<.001; odds ratio [OR] 0.512, 95% CI 0.422-0.621), and risk factors, including increased age (P=.004; OR 1.014, 95% CI 1.004-1.024), misdiagnosis at the first clinical visit (P<.001; OR 3.553, 95% CI 2.886-4.375), and the time interval from onset to treatment (P=.001; OR 1.026, 95% CI 1.011-1.042). Subgroup analyses identified risk factors associated with P falciparum, which include advanced age (P=.004; OR 1.015, 95% CI 1.005-1.026), initial misdiagnosis during the first clinical visit (P<.001; OR 3.549, 95% CI 2.827-4.455), the time interval from onset to treatment (P<.001; OR 1.043, 95% CI 1.022-1.063), and a delay of more than 3 days from the first treatment to diagnosis (P<.001; OR 2.403, 95% CI 1.823-3.164). Additionally, the risk factors pertaining to P ovale involve misdiagnosis at the initial clinical visit (P=.01; OR 2.901, 95% CI 1.336-6.298), the time interval from onset to treatment (P=.002; OR 1.095, 95% CI 1.033-1.160), and the duration from the initial treatment to diagnosis (P=.43; OR 1.032, 95% CI 0.953-1.118). Previous infections can prevent the progression of both P falciparum and P ovale. Conclusions: This study showed that the increasing proportion of P ovale in recent years should not be ignored. Furthermore, there is a need to improve diagnostic awareness, enhance the capacity of medical institutions, and provide health education for high-risk groups.

Morbidity burden of imported chronic schistosomiasis among West African migrants.

BACKGROUND: Past exposure to schistosomiasis is frequent among migrants from endemic countries, and chronic untreated infection may lead to long-term morbidities. METHODS: We carried out a prospective population-based cross-sectional study among migrants from endemic Sub-Saharan countries living in Barcelona, Spain. Participants had not been previously diagnosed or treated for schistosomiasis. Clinical signs and symptoms were scrutinised through a systematic revision of electronic medical records and an on-site standardised questionnaire, and blood and urine samples were screened for Schistosoma. FINDINGS: We recruited 522 eligible participants, 74.3% males, mean age 42.7 years (SD=11.5, range 18-76), Overall, 46.4% were from Senegal and 23.6% from Gambia. They had lived in the European Union for a median of 16 years (IQR 10-21). The prevalence of a Schistosoma-positive serology was 35.8%. S. haematobium eggs were observed in urine samples in 6 (1.2%) participants. The most prevalent symptoms among Schistosoma-positive participants were chronic abdominal pain (68.8%, OR=1.79; 95%CI 1.2-2.6), eosinophilia (44.9%, OR=2.69; 95%CI 1.8-4.0) and specific symptoms associated with urinary schistosomiasis, like self-reported episodes of haematuria (37.2%; OR=2.47; 95%CI 1.6-3.8), dysuria (47.9%, OR=1.84; 95%CI=1.3-2.7) and current renal insufficiency (13.4%; OR=2.35; 95%CI=1.3-4.3). We found a significant prevalence of gender-specific genital signs and symptoms among females (mainly menstrual disorders) and males (erectile dysfunction and pelvic pain). Individuals typically presented with a multitude of interconnected symptoms, most commonly chronic abdominal pain, which are often disregarded. CONCLUSIONS: Despite the lack of urine parasite identification, the high incidence of clinical signs and symptoms strongly correlated with a positive schistosomiasis serology suggests the existence of a heavy clinical burden among long-term West African migrants living for years/decades in the study region. More research is urgently required to determine whether these symptoms are the result of long-term sequelae or a persistent active Schistosoma infection.

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.

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.

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.

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.

Imported Loiasis at a Clinical Reference Center in Germany: A Retrospective Case Series.

Loiasis is a rarely imported infectious disease that is often difficult to diagnose and treat. Here we describe clinical features and treatment outcomes of 11 patients with imported loiasis seen at a German reference center between 2013 and 2023. Clinical presentations varied by patient origin, with eye-worm migration and ophthalmological symptoms being more common among patients from endemic areas and Calabar swelling, subcutaneous swelling, and pruritus more prevalent among returning travelers from nonendemic regions. Eosinophil counts were higher in returning travelers. Diethylcarbamazine was most commonly used for treatment either as monotherapy in combination with ivermectin or with albendazole and ivermectin, respectively. In one patient, long-term follow-up indicated treatment failure after the first course of treatment. Another traveler was prescribed chemoprophylaxis with diethylcarbamazine after experiencing repeated infections due to long-term residence in a high-risk region in Cameroon.

Screening for tropical and imported infections in migrant kidney transplant candidates from the kidney transplant access consultation.

BACKGROUND AND OBJECTIVE: Kidney transplantation (KT) should be postponed in those people with active bacterial, fungal, viral and parasitic processes, since these must be treated and resolved previously. The objective of this study is to present the screening circuit implemented by the Nephrology clinic and describe the prevalence of tropical and imported infections in KT candidates born or coming from endemic areas. MATERIALS AND METHODS: Descriptive cross-sectional study, carried out in 2021. Sociodemographic and clinical variables, serological data of general infections and specific tests of tropical infectious diseases were collected. A descriptive analysis of the data was carried out. RESULTS: 67 TR candidates from Latin America (32.8%), North Africa (22.4%), Sub-Saharan Africa (14.9%) and Asia (29.9%) were included. 68.7% were men and the mean age was 48.9 ±â€¯13.5 years. After the general and specific studies, 42 (62.7%) patients were referred to the Infectious Diseases Service to complete this study or indicate treatment. 35.8% of the patients had eosinophilia, and in one case parasites were detected in feces at the time of the study. Serology for strongyloidiasis was positive in 18 (26.9%) cases, while positive serology for other tropical infections was hardly detected. 34.3% of patients had latent tuberculosis infection. CONCLUSIONS: The prevalence of tropical and imported infections in migrant candidates for RT was low, except for strongyloidiasis and latent tuberculosis infection. Its detection and treatment are essential to avoid serious complications in post-TR. To this end, the implementation of an interdisciplinary screening program from the KT access consultation is feasible, necessary and useful.

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.

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.

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.

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.

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.