Delay in diagnosis of imported Plasmodium falciparum malaria in children

Pre-hospital time delays in imported malaria diagnosis in hospitalized sub-Saharan travelers and migrants: not only on the patient's shoulders

PURPOSE

To analyze the diagnostic delay in malaria related to misdiagnosis at first medical visit and its association with the risk of severe malaria in non-endemic areas.

METHODS

Retrospective observational study of sub-Saharan migrants with imported malaria from January-2010 to December-2022. Patients were allocated in two groups depending on if malaria was suspected at first medical visit or not. Time delays in seeking healthcare, medical diagnostic delay (time between first attending a medical facility and the diagnosis of malaria) and total diagnostic delay (time between the onset of symptoms and the diagnosis of malaria) were calculated.

RESULTS

297 patients were included in the analysis. At first medical visit, malaria was misdiagnosed in 137 patients (46.1%). Medical diagnostic delay and total diagnostic delay were larger for the misdiagnosis group than for those properly diagnosed at first visit (p < 0.001). Although time in seeking healthcare was shorter in the misdiagnosis group, the presence of suggesting symptoms, such as fever, was lower (p < 0.050). Misdiagnosis was more frequent in emergency rooms linked to primary healthcare (p < 0.001). For the overall population (n = 297), total diagnostic delay was mainly due to delay in seeking healthcare. Initial misdiagnosis was associated with a higher risk of severe malaria (adjusted OR 2.23 [1.09-5.10], p = 0.031).

CONCLUSION

In a non-endemic area with a high rate of imported malaria, the percentage of patients misdiagnosed is surprisingly high. Misdiagnosis is associated with longer medical and total diagnostic delays and with a higher risk of severe malaria. It seems necessary to redesign training programs to improve knowledge among healthcare professionals and actions targeted to travelers to promote seeking healthcare advice promptly.

Scoring systems for prediction of malaria and dengue fever in non-endemic areas among travellers arriving from tropical and subtropical areas

BACKGROUND

Fever is a common symptom among travellers returning from tropical/subtropical areas to Europe, and promptly distinguishing severe illnesses from self-limiting febrile syndromes is important but can be challenging due to non-specific clinical presentation.

METHODS

A cross-sectional study enrolled adults and children who sought care during 2015-2020 at Karolinska University Hospital, Stockholm, Sweden with fever within 2 months after returning from travel to a tropical/subtropical area. Data on symptoms and laboratory parameters were prospectively and retrospectively collected. Two separate scoring systems for malaria and dengue were developed based on backward elimination regressions.

RESULTS

In total, 2113 adults (18-94 years) and 202 children (1-17 years) were included, with 112 (4.8%) confirmed malaria by blood thick smear and 90 (3.9%) PCR/serology dengue-positive cases. Malaria was more likely in a patient who had visited sub-Saharan Africa and presented with combination of thrombocytopenia, anaemia and fever ≥39.5°C. Leucopenia, muscle pain and rash after travelling to Asia or South/Latin America indicated high probability of dengue. Two scoring systems with points between 0 and 7 for prediction of malaria or dengue were created based on the above predictors. Scores ≥3 indicated >80% sensitivity and specificity for malaria and >90% specificity for dengue in children and adults (area under the curve (AUC) for dengue: 0.92 in adults (95% CI 0.90 to 0.95) and 0.95 in children (95% CI 0.88 to 1.0); AUC for malaria: 0.93 in adults (95% CI 0.91 to 0.96) and 0.88 in children (95% CI 0.78 to 0.99)). Internal validation of optimism and overfitting was managed with bootstrap.

CONCLUSION

The presented scoring systems provide novel tools for structured assessment of patients with tropical fever in a non-endemic area and highlight clinical signs associated with a potential severe aetiology to direct the need for microbial investigation.

Care-seeking delay of imported malaria to China: implications for improving post-travel healthcare for migrant workers

BACKGROUND

Imported malaria cases continue to pose major challenges in China as well as in other countries having achieved elimination. Our study aims to identify the factors influencing the timing of care-seeking after symptom onset among migrant workers with imported malaria, in order to develop innovative interventions to improve access and provision of post-travel healthcare for returning migrants.

METHODS

We analysed the timing and types of healthcare service utilization after symptom onset among patients with imported malaria between 2012 and 2019 in Jiangsu Province, China. Moreover, decision tree models were used to explore the factors influencing the care-seeking timing after symptom onset among patients with imported malaria.

RESULTS

A total of 2255 cases of imported malaria were identified from 1 June 2012 through 31 December 2019. Patients with malaria imported into China were mainly male migrant labourers returning from sub-Saharan Africa (96.8%). A substantial number of patients with imported malaria sought healthcare >3 days after symptom onset, which clearly represented delayed healthcare-seeking behaviour. According to the decision tree analysis, initial healthcare seeking from healthcare facilities at higher administrative levels, infection with Plasmodium vivax and absence of malaria infection history were significantly associated with delayed healthcare seeking in patients with imported malaria.

CONCLUSION

The delay in seeking of medical care among migrant workers with imported malaria should be considered and addressed by specific interventions. In addition to increasing awareness about these issues among health care professionals, improved access to healthcare facilities at higher administrative levels as well as improved diagnostic capacity of healthcare facilities at lower administrative levels should be developed. Moreover, education programs targeting populations at risk of malaria importation and delayed healthcare seeking should be improved to facilitate early healthcare seeking and service use.

Internationally Acquired Severe Systemic Infections in Febrile Pediatric Travelers Presenting to the Emergency Department

OBJECTIVES

Most children in the United States who visit the emergency department (ED) with fever have minor illnesses not requiring treatment or hospitalization. However, when a child has recently immigrated or traveled abroad, internationally acquired severe systemic infections (ISSIs) must be considered. We sought to describe children who have traveled internationally and present to the ED with a complaint of fever and to determine risk factors associated with ISSIs in these patients.

METHODS

We conducted a retrospective study of children younger than 18 years who presented to 2 pediatric EDs in Bronx, NY (June 2007 to May 2017). Patients were included if they had both fever within 24 hours and international travel within 30 days. We compared groups using bivariate analyses and created a prediction model for ISSIs using multivariable logistic regression.

RESULTS

Of the 353 children included, 44 (12%) had ISSI: 25 (57%), malaria; 6 (14%), dengue; and 13 (30%), bacteremia. Eight (18%) of those with ISSI presented with fever to another medical provider in the week prior but did not receive bloodwork. Four variables were independently associated with ISSIs: headache (odds ratio [OR], 21.7; 95% confidence interval [CI], 6.8-69.3), travel to Africa or Asia (OR, 18.8; 95% CI, 4.8-73.2), platelets of 150,000/μL or less (OR, 15.1; 95% CI, 4.7-48.6), and alanine aminotransferase level of 30 IU/L or greater (OR, 8.9; 95% CI, 3.1-25.3).

CONCLUSIONS

Children who travel internationally and present with fever upon return are at substantial risk for developing ISSIs. The diagnosis of ISSIs is often overlooked, but certain risk factors have the potential to aid clinicians.

Barriers to seeking health care among returning travellers with malaria: A systematic review

OBJECTIVE

To identify barriers to seeking health care among returning travellers with malaria with the aim of developing targeted interventions that improve early health care-seeking behaviour, diagnosis and treatment.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic review of published medical literature, selecting studies that investigated and reported barriers to seeking health care among returning travellers and migrants with malaria. In total, 633 articles were screened, of which four studies met the inclusion criteria after a full-text review.

RESULTS

The four studies reported barriers to seeking healthcare among returning travellers in China, the United States, Thailand and the Dominican Republic. Three studies had an observational design. The identified barriers were summarised based on the appraisal delay, illness delay and utilisation delay stages. During appraisal delays, low awareness of malaria was the most significant factor. Once the patient assessed that he or she was ill, belonging to a specific minority ethnicity, being infected with P. vivax and receiving a low level of social support were predictors of delayed health care-seeking. Finally, the most significant factor associated with utilisation delays was the monetary cost.

CONCLUSION

The health care-seeking behaviour of returning travellers with malaria should be further investigated and improved. Addressing the identified barriers and gaps in health care-seeking behaviour among returning travellers with malaria, particularly among groups at high risk of travel-associated infections, is important to prevent severe disease and deaths as well as secondary transmission and epidemics.

Severe imported Plasmodium falciparum malaria in children: characteristics and useful factors in the risk stratification

BACKGROUND

Severe imported pediatric malaria is of concern in non-endemic settings. We aimed to determine the features of pediatric severe cases in order to design a model able to stratify patients at presentation.

METHODS

We conducted a retrospective cross-sectional study including all imported P. falciparum malaria infection in patients ≤14 years of age, treated from January 2008 to February 2019 in two tertiary hospitals: Brescia, Italy and Barcelona, Spain. Severe malaria was defined according to World Health Organization criteria. Mortality rate, pediatric intensive care unit (PICU) stay and blood transfusion were analysed as adverse outcomes.

RESULTS

Out of 139 children included, 30.9% were severe malaria. Twenty-seven (19.4%) were admitted to PICU, and transfusion was required in 14 cases (10.1%). Predictors for severe malaria were: young age, low hemoglobin, high white blood cells (WBC) and high C-reactive protein. Platelet <130,000/μl correlated with severe malaria (without statistical significance). A model that includes age, WBC and C-reactive protein shows a high specificity to classify patients without severe malaria (92.3%) with 70% PPV and 75% NPV.

CONCLUSIONS

A score based on patient's age, WBC and C-reactive protein easily available at emergency room can help to identify children with higher risk of adverse outcomes.

Does Malaria Cause Diarrhoea? A Systematic Review

Malaria is a systemic febrile disease that may progress to prostration, respiratory distress, encephalopathy, anemia, and death. Malaria is also an established risk factor for invasive bacterial disease caused, in the majority of cases, by invasive enteropathogens and in particular by non-Typhoidal Salmonella (NTS). Whilst various malaria-related pathologies have been implicated in the risk of NTS bacteraemia in animal models, including intestinal dysbiosis and loss of gut homeostasis, clinical evidence is lacking. As a first step in gathering such evidence, we conducted a systematic review of clinical and epidemiological studies reporting the prevalence of diarrhoea among malaria cases and vice versa. Database searches for "plasmodium" and "diarrhoea" identified 1,771 articles; a search for "plasmodium" and "gastroenteritis" identified a further 215 articles. After review, 66 articles specified an association between the search terms and referred primarily, but not exclusively, to Plasmodium falciparum infections. Overall, between 1.6 and 44% of patients with acute malaria infection reported symptoms of diarrhoea (812 of 7,267 individuals, 11%) whereas 5-42% of patients presenting to hospital with diarrhoea had an underlying malaria parasite infection (totaling 749 of 2,937 individuals, 26%). However, given the broad range of estimates, a paucity of purposeful case control or longitudinal studies, and varied or poorly specified definitions of diarrhoea, the literature provides limited evidence to draw any firm conclusions. The relationship between malaria and gastrointestinal disturbance thus remains unclear. Carefully designed case-control studies and prospective longitudinal studies are required to confidently assess the prevalence and significance of intestinal manifestations of malaria parasite infection.

Conduite à tenir devant un enfant fébrile au retour de voyage☆

Les pathologies le plus fréquentes au retour de voyage à l’étranger sont les infections gastro-intestinales, les maladies fébriles et les problèmes dermatologiques. L’évaluation d’un enfant fébrile de retour de voyage est clinique : vérification des antécédents et des vaccinations, recherche d’autres cas au contact, signes fonctionnels et physiques, caractéristiques du voyage. Un bilan paraclinique de débrouillage complète souvent l’évaluation pour une orientation syndromique. Si les causes de fièvre sont surtout cosmopolites, la gravité des pathologies exotiques doit les faire rechercher en priorité. Le paludisme doit être évoqué devant toute fièvre en provenance d’Afrique subsaharienne. Le diagnostic repose sur l’association d’un frottis sanguin et d’un test sensible (goutte épaisse, polymerase chain reaction [PCR]) ou d’un test de diagnostic rapide (pour Plasmodium [P ]. falciparum ). Les critères clinicobiologiques de gravité sont essentiels pour orienter et traiter le patient. En cas d’accès non compliqué à P. falciparum , le traitement repose sur une thérapie combinée à base d’artémisinine (ACT), artéméther-luméfantrine ou arténimol-pipéraquine. Les accès graves sont traités par l’artésunate intraveineux, puis un ACT oral. Dengue, chikungunya et infection à virus Zika ont des caractéristiques cliniques communes (association fièvre-éruption-arthralgies, traitement symptomatique). En cas de dengue, il faut surveiller l’apparition de signes d’alerte qui pourraient faire craindre une évolution péjorative. Le chikungunya est grave en cas de transmission per partum, avec un risque d’encéphalite néonatale. Chez l’enfant, le Zika est a- ou peu symptomatique. Mais en cas d’infection pendant une grossesse, le risque est celui d’une embryofœtopathie. Le diagnostic de ces arboviroses repose sur la PCR à la phase aiguë et la sérologie secondairement. La symptomatologie de la typhoïde est peu spécifique, justifiant la pratique d’hémocultures systématiques devant une fièvre du retour. Son traitement repose sur les céphalosporines de troisième génération ou la ciprofloxacine, mais les résistances augmentent. Au total, la diversité des étiologies d’une fièvre de retour et la gravité potentielle des infections importées imposent une réflexion sur le parcours de soins de ces patients, en particulier vis-à-vis du risque de fièvre hémorragique.

Conducta práctica ante un niño febril al regresar de un viaje

Las enfermedades más frecuentes al regresar de un viaje al extranjero son las infecciones gastrointestinales, las enfermedades febriles y los problemas dermatológicos. La evaluación de un niño febril al regreso de un viaje es clínica: verificación de los antecedentes y las vacunaciones, búsqueda de otros casos en contacto, signos funcionales y físicos, y características del viaje. Unas pruebas complementarias de rutina completan a menudo la evaluación para una orientación sindrómica. Si bien las causas de fiebre son, sobre todo, cosmopolitas, la gravedad de la enfermedad exótica obliga a buscarlas prioritariamente. El paludismo debe sospecharse ante una fiebre procedente de África subsahariana. El diagnóstico se basa en la asociación de un frotis sanguíneo y una prueba sensible (gota gruesa, reacción en cadena de la polimerasa [PCR]) o una prueba de diagnóstico rápido (para Plasmodium falciparum ). Los criterios clínico-biológicos de gravedad son esenciales para orientar y tratar al paciente. En caso de acceso no complicado por P. falciparum, el tratamiento se basa en un tratamiento combinado a base de artemisinina (ACT), arteméter-lumefantrina o artenimol-piperaquina. Los accesos graves se tratan con artesunato intravenoso, seguido de ACT oral. Dengue, chikungunya e infección por virus Zika tienen características clínicas comunes (fiebre-erupción-artralgias, tratamiento sintomático). En caso de dengue, conviene controlar la aparición de signos de alerta, que podrían hacer temer una evolución negativa. El chikungunya es grave en caso de transmisión en el parto, con un riesgo de encefalitis neonatal. En el niño, el Zika es asintomático o poco sintomático. Pero, en caso de infección durante el embarazo, el riesgo es el de una embriofetopatía. El diagnóstico de estas arbovirosis se basa en la PCR en la fase aguda y en la serología secundariamente. La sintomatología de la fiebre tifoidea es poco específica, lo cual justifica la práctica de hemocultivos sistemáticos ante una fiebre tras un viaje. Su tratamiento se basa en las cefalosporinas de tercera generación o el ciprofloxacino, pero las resistencias aumentan. En suma, la diversidad de las etiologías de una fiebre al regreso de un viaje y la potencial gravedad de las infecciones importadas imponen una reflexión sobre el proceso de tratamiento de estos pacientes, en especial en lo referente al riesgo de fiebre hemorrágica.

Monitoring and evaluation of intervals from onset of fever to diagnosis before "1-3-7" approach in malaria elimination: a retrospective study in Shanxi Province, China from 2013 to 2018

BACKGROUND

China's 1-3-7 approach was extensively implemented to monitor the timeframe of case reporting, case investigation and foci response in the malaria elimination. However, activities before diagnosis and reporting (before '1') would counteract the efficiency of 1-3-7 approach but few data have evaluated this issue. This study aims to evaluate the timelines between onset of fever and diagnosis at healthcare facilities in Shanxi Province.

METHODS

Routine data were extracted from IDIRMS and NMISM database from 2013 to 2018. Time intervals between onset of fever and healthcare-seeking and between healthcare-seeking and diagnosis were calculated. Each of the documented malaria cases was geo-coded and paired to the county-level layers of polygon.

RESULTS

A total of 90 cases were reported in 2013-2018 in Shanxi Province, and 73% of cases reported at provincial health facilities. All malaria cases were imported from Africa (90%) and Southeast Asia (10%) especially around the Chinese Spring Festival (n = 46, 51%). The median days between fever and healthcare-seeking and between healthcare-seeking and diagnosis of malaria were 3 and 2, respectively.

CONCLUSIONS

The current "1-3-7" approach is well executed in Shanxi Province, but delays intervals observed in case finding before 1-3-7 approach occurred in all levels of facilities in Shanxi Province, which imply that more efforts are highlighted for timely case finding. Health education should be provided for improving awareness of healthcare-seeking, and various technical training aiming at the physicians should be carried out to improve diagnosis of malaria.

Accuracy of malaria diagnosis by clinical laboratories in Belgium

BACKGROUND

The Belgian Reference Laboratory for Plasmodium offers a free-of-charge reference testing of malaria-positive or doubtful samples to clinical laboratories.

METHODS

The final malaria diagnosis from the Reference Laboratory (microscopy, rapid diagnostic tests (RDTs) and Plasmodium species-specific PCR) were compared with the final diagnosis from peripheral Belgian laboratories. The Reference Laboratory reports were analysed for all samples submitted between 2013 and 2017. Criteria assessed included the diagnosis of malaria, Plasmodium species identification including mixed infections, and in case of Plasmodium falciparum, the parasite density and the presence of sexual and asexual stages.

RESULTS

A total of 947 non-duplicate samples were included. Reference testing confirmed 96.3% (893/927) and 90.0% (18/20) samples submitted as positive and negative, respectively, the two missed diagnoses were samples with Plasmodium ovale and Plasmodium malariae. Submitting laboratories had correctly identified P. falciparum in 95.1% (508/534) samples with P. falciparum single infection. They had correctly diagnosed the species in 62.9% (95/151) single non-falciparum samples and had reported 'non-falciparum' in another 26 (17.2%) samples; most errors occurred among P. malariae (n = 8/21, 38.1%) and P. ovale (n = 14/51, 27.5%). Only one of the 21 mixed Plasmodium species infections had been diagnosed as such by the submitting laboratories; in three of them, P. falciparum had been overlooked. Taken single and mixed infections together, P. falciparum was diagnosed in 98.6% (546/554) samples. Among 471 single P. falciparum samples available for comparison, laboratories had correctly reported parasite densities above 2% in 87.5% (70/80) samples; they had incorrectly reported parasite densities > 2% in an extra 52 (8.9%) samples. Laboratories had correctly reported P. falciparum schizonts and gametocytes in 25.6% (11/43) and 56.7% (17/30) samples, respectively.

CONCLUSION

Diagnostic laboratories in a malaria non-endemic setting provided excellent diagnosis of malaria and P. falciparum, reasonably good diagnosis of non-falciparum infections and acceptable calculation of P. falciparum parasite density.

Transmission Risk from Imported Plasmodium vivax Malaria in the China-Myanmar Border Region

Malaria importation and local vector susceptibility to imported Plasmodium vivax infection are a continuing risk along the China–Myanmar border. Malaria transmission has been prevented in 3 border villages in Tengchong County, Yunnan Province, China, by use of active fever surveillance, integrated vector control measures, and intensified surveillance and response.

How to interpret malaria tests

There are over 300 new cases of imported paediatric malaria in the UK each year and this has been increasing over the last 20 years. Malaria in children is particularly difficult to diagnose because the initial presenting features are subtler than in adults and do not display the classical presenting features. However, they are also more likely to deteriorate rapidly and to develop severe malaria. The 'gold standard' for ruling out the diagnosis of malaria if clinically suspected is three negative thin and thick blood films, which require serial phlebotomy and the availability of trained technicians. There are now a range of other tests, including rapid diagnostic tests and PCR, as well as clinical features that make the diagnosis more or less likely. We explore the different tests available and whether these might replace the three negative blood films currently needed. We also look at whether we are able to use clinical features to aid the tests used for a diagnosis of imported malaria.

Knowledge gaps in the diagnosis and management of patients with tropical diseases presenting to Canadian emergency departments: are the gaps being met?

OBJECTIVE

We conducted a needs assessment to identify knowledge gaps in the management of tropical diseases by Canadian emergency physicians and identify available, related continuing medical education (CME) resources.

METHODS

A literature review was conducted to summarize challenges in the management of commonly encountered tropical diseases. An anonymous online survey was administered to Canadian emergency physicians using the Canadian Association of Emergency Physicians survey deployment service in July and August 2012. The survey identified self-reported gaps in knowledge and assessed knowledge using case-based vignettes. A list of CME resources was generated from a review of major academic emergency medicine journals, online cases, and conference topics from emergency medicine associations during 2010-2011. Two independent reviewers assessed the relevance of the resources; differences were resolved by consensus.

RESULTS

From 635 citations, 47 articles were selected for full review; the majority (66%) were retrospective chart reviews, few (10.6%) had an emergency medicine focus, and fewer still were Canadian (8.5%). In total, 1,128 surveys were distributed, and 296 (27%) participants were included in the study. Most respondents reported "no" (52.4%) or "some" (45.9%) training in tropical medicine. Most (69.9%) rated their comfort in managing patients with tropical diseases as "low." Few (11.1%) respondents reported a tropical disease being misdiagnosed or mismanaged; 44.1% indicated malaria. The perceived need for further training was high (76.7%). Conference workshops were the most highly requested CME modality, followed by case studies and podcasts. Correct answers to case vignettes ranged from 30.7 to 58.4%. Although 2,038 CME titles were extracted from extensive searches, only 6 were deemed relevant.

CONCLUSIONS

Most Canadian emergency physicians have had minimal training in tropical diseases, reported a low comfort level in their management, and identified a high need for CME opportunities, which are lacking.

Quality of reporting of studies evaluating time to diagnosis: a systematic review in paediatrics

OBJECTIVE

An ever-increasing number of studies analyses the distribution, determinants and consequences of time to diagnosis and delays. Weaknesses in their reporting can impede the assessment of the risks of bias and variation and thus create a risk of invalid conclusions and counterproductive clinical and public health efforts. This study sought to assess systematically the quality of reporting of articles about time to diagnosis in paediatrics.

DESIGN

Two authors identified and analysed the quality of reporting of 50 consecutive articles assessing these intervals published from 2005 through October 2011, according to a checklist we developed of 35 items potentially associated with risks of bias and variation.

MAIN OUTCOME MEASURE

Frequency of articles reporting each item.

RESULTS

Symptoms that should trigger a diagnostic procedure were reported in 28% of the articles; only two articles reported whether all patients with these symptoms underwent that procedure. Only 44% of the articles defined the beginning of the illness, 46% the date of diagnosis and 60% the distribution of time to diagnosis. Two studies met the criteria for all 11 items considered essential for assessing the risks of bias and variation in this type of study.

INTERPRETATION

This study identified many weaknesses in the quality of reporting of studies of time to diagnosis in paediatrics, especially for items potentially related to risks of bias and variation. This finding underlines the need for the development of new (or the refinement of existing) guidelines for reporting this type of study.

Migration and malaria in europe

The proportion of imported malaria cases due to immigrants in Europe has increased during the lasts decades, with higher rates associated with settled immigrants who travel to visit friends and relatives (VFRs) in their country of origin. Cases are mainly due to P. falciparum and Sub-Saharan Africa is the most common origin. Clinically, malaria in immigrants is characterised by a mild clinical presentation including asymptomatic or delayed malaria cases and low parasitic levels. These characteristics may be explained by a semi-immunity acquired after long periods of time exposed to stable malaria transmission. Malaria cases among immigrants, even asymptomatic patients with sub-microscopic parasitemia, could increase the risk of transmission and cause the reintroduction of malaria in certain areas that have adequate vectors and climate conditions. Moreover, imported malaria cases in immigrants can also play an important role in the non-vector transmission out of endemic areas, through blood transfusions, organ transplantation or congenital transmission or occupational exposures. Consequently, outside of endemic areas, malaria screening should be carried out among recently arrived immigrants coming from malaria endemic countries. The aim of screening is to reduce the risk of clinical malaria in the individual as well as to prevent autochthonous transmission of malaria in areas where it has been eradicated.

Clinical practice: the diagnosis of imported malaria in children

The present paper reviews the diagnosis of imported malaria in children. Malaria is caused by a parasite called Plasmodium and occurs in over 100 countries worldwide. Children account for 10-15% of all patients with imported malaria and are at risk to develop severe and life-threatening complications especially when infected with Plasmodium falciparum. Case-fatality ratios vary between 0.2% and 0.4%. Children visiting friends and relatives in malaria endemic areas and immigrants and refugees account for the vast majority of cases. Symptoms are non-specific and delayed infections (more than 3 months after return from an endemic country) may occur. Microscopic analysis of the thick blood film is the cornerstone of laboratory diagnosis. For pragmatic reasons, EDTA-anticoagulated blood is accepted, provided that slides are prepared within 1 h after collection. Information about the Plasmodium species (in particular P. falciparum versus the non-falciparum species) and the parasite density is essential for patient management. Molecular methods in reference settings are an adjunct for species differentiation. Signals generated by automated hematology analyzers may trigger the diagnosis of malaria in non-suspected cases. Malaria rapid diagnostic tests are reliable in the diagnosis of P. falciparum but not for the detection of the non-falciparum species. They do not provide information about parasite density and should be used as an adjunct (and not a substitute) to microscopy. In case of persistent suspicion and negative microscopy results, repeat testing every 8-12 h for at least three consecutive samplings is recommended. A high index of suspicion and a close interaction with the laboratory may assure timely diagnosis of imported malaria.

Pediatric malaria: 8-year case series in Atlanta, Georgia, and review of the literature

BACKGROUND

Although malaria is frequent in travelers, it is often misdiagnosed on initial presentation, especially in children. The objective of this study is to describe epidemiology, clinical and laboratory presentation, and treatment of children with malaria in the United States.

METHODS

We performed a retrospective review of 50 confirmed cases of malaria from two pediatric metropolitan hospitals in Atlanta, GA, from 2000 to 2008.

RESULTS

Malarial smears were performed in 385 unique patients; 50 (12.6%) were positive. American children who had visited family and friends in malaria-endemic countries comprised 62% of our cases. Most cases visited Nigeria or Cameroon; all but three traveled to Africa. Three patients presented 8 to 12 months following travel. Plasmodium falciparum was diagnosed most frequently (72%). Most patients had low-level parasitemia (<1%). Gametocytes were rarely identified. Treatment was primarily with quinine and either doxycycline or clindamycin, and transfusion was rare. All patients responded rapidly to treatment. Although seven (14%) had hyperparasitemia (> 5%), no fatalities or long-term sequelae were seen.

CONCLUSIONS

Malarial diagnosis can be difficult in children because parasitemia is usually below 1%. A high index of suspicion is required in patients who have traveled to Africa.

[Imported malaria: diagnostic traps and rapid tests]

Imported malaria is a disease prevalent in France: 6,000 to 8,000 cases a year, of which 15% are pediatric cases. Despite this high incidence, the diagnosis is often delayed. The patient may then evolve to a severe form. This diagnostic delay is due to non-specific clinical symptoms in children. The most common symptoms are fever and digestive disorders (diarrhea, vomiting). In the absence of thrombocytopenia, the laboratory tests are not very useful for diagnosis. Parasitological examinations are dependent on the experience of the biologist, particularly in cases of low parasitemia as those observed in children who have received partial chemoprophylaxis. The recent introduction of rapid tests based on the detection of Plasmodium proteins, allows emergency remedy to this problem. The blood smears remains the gold standard and has to be used to confirm the results of rapid tests. If rapid tests improve the detection of Plasmodium in 2009, it remains mandatory to evoke the diagnosis of malaria in any febrile child coming from an endemic area.

Imported malaria in children: incidence and risk factors for severity

To assess the incidence of imported malaria in children and to determine the frequency of delayed diagnosis and risk factors for severe malaria, we performed a retrospective multicenter cohort study in the northern region of France and included all children with a positive test for malaria from 2000 to 2006. The incidence of imported malaria in children <18 years, the frequency of a delayed diagnosis, and the risk factors for severe malaria were determined. The study identified 133 children with imported malaria. The mean incidence of this disease was 1.9/100 000 children <18 years (95% confidence interval [CI], 1.6-2.2). Detailed data were available for 120 children. Disease was considered severe in 19% of cases. The diagnosis was delayed (> or =1 day after the first medical contact) in 31% of cases, and this delay was the only independent risk factor identified for severe imported malaria in children (adjusted odds ratio, 3.2; 95% CI, 1.2-8.8; P = 0.02).

Pediatric and adolescent imported malaria in Cape Town

We reviewed 42 cases of pediatric and adolescent imported malaria in Cape Town. Patients were predominantly new and returned immigrants from other African countries. Rapid diagnosis occurred in most cases. Eleven of 42 (26%) had severe malaria. Management issues included delay to and inappropriate treatment, inadequate monitoring for hypoglycemia, and under notification to health authorities.

Malaria overdiagnosis and burden of malaria misdiagnosis in the suburbs of central Sudan: special emphasis on artemisinin-based combination therapy era

Accuracy of diagnosis is central for malaria control. Although microscopy is gold standard in malaria diagnosis, its reliability is largely dependent on user skill. In this study, we evaluated practitioners' clinical and microscopists' technical skills in diagnosis of malaria in central Sudan. In a retrospective study, 3203 blood smears from 95 peripheral health facilities (each represented by a general practitioner [GP] and general microscopist [GM]) were reexamined by expert microscopist. Furthermore, in a prospective study, 410 patients had their malaria diagnosis rechecked by rapid diagnostic test for validation of the microscopic diagnosis. Results showed that the rate of false-positive diagnosis of malaria was 75.6% and false-negative diagnosis was 0.01%. The study disclosed poor skills of the GPs and GMs in malaria diagnosis because 43% of the GPs and 44% of the GMs failed to make a single true-positive malaria diagnosis. The false-positive malaria diagnosis showed bias toward adult females. Economically, the calculated cost of diagnosis and treatment of malaria in Sudan in year 2000 is US$100 million, whereas the calculated cost of true malaria is approximately US$14 million. In conclusion, malaria overdiagnosis was widely recognized in central Sudan, with high economic burden during the era of artemisinin-based combination therapy. Finally, different scenarios were suggested for improvement of malaria diagnosis.