Age as a risk factor for severe manifestations and fatal outcome of falciparum malaria in European patients: observations from TropNetEurop and SIMPID Surveillance Data

Hemophagocytic lymphohistiocytosis-how common and how severe is it as a complication of malaria? Retrospective case series and review of the literature

BACKGROUND

Infection-associated secondary hemophagocytic lymphohistiocytosis (sHLH) is a potentially life-threatening hyperinflammatory condition caused by various infectious diseases. Malaria has rarely been described as trigger. The aim of this study is to collect data on frequency, clinical spectrum, and outcome of sHLH induced by malaria.

METHODS

We collected case numbers on malaria and malaria-associated sHLH from specialized centers in Germany from 2015 to 2022. In addition, we conducted a literature search on published cases of malaria-associated sHLH and systematically analyzed the literature regarding clinical and diagnostic criteria.

RESULTS

We obtained data from 13 centers treating 1461 malaria cases with different Plasmodium species, of which 5 patients (0.34%) also were diagnosed with sHLH. The literature search revealed detailed case reports from further 51 patients and case series comprising the description of further 24 patients with malaria-associated sHLH. Most cases (48/80; 60%) were reported from Asia. The median time interval between onset of malaria symptoms and hospital admission was 7 days. Severe complications of sHLH were documented in 36% (20/56) of patients, including two patients with multiple organ failure in our case series. Only 41% (23/56) of patients received specific treatment for sHLH, nevertheless the mortality rate (CFR) of 5% is lower compared to the CFR reported for sHLH triggered by other infectious diseases (e.g., 25% in sHLH due to EBV infection).

CONCLUSION

Malaria-associated sHLH appears to have a comparatively good prognosis but may still represent an underdiagnosed and potentially fatal complication of malaria, especially in resource-poor settings.

Characteristics of preventive intervention acceptance for international travel among clients aged 60 years and older from a Japanese multicenter pretravel consultation registry

OBJECTIVES

Pretravel consultation (PTC) is important for older adults owing to health problems associated with overseas travel. Although older adults in Japan, their PTC characteristics are less known. This study aimed to investigate the epidemiology of clients aged ≥ 60 years based on data from the Japan Pre-travel Consultation Registry (J-PRECOR).

METHODS

Clients aged ≥ 60 years who visited J-PRECOR cooperative hospitals from February 1, 2018, to May 31, 2022, were included. The primary endpoint was a comparison of prescriptions for vaccines for hepatitis A, tetanus toxoid, and malaria prophylaxis in travelers to high-risk malaria countries in yellow fever vaccination (YFV)-available facilities with and without YFV.

RESULTS

In total, 1000 clients (median age: 67 years) were included. Although 523 clients were immunized with YFV, only 38.6% of the 961 unimmunized clients were vaccinated with the tetanus toxoid-containing vaccine. Malaria chemoprophylaxis was prescribed to 25.7% of clients traveling for ≤55 days. At YFV-capable institutes, 557 clients traveling to yellow fever risk countries took PTC, 474 of whom received YFV and 83 were unvaccinated. Lower age (odds rate 0.85 per 1 year; 95% CI 0.80-0.90) and lower hepatitis A vaccination rate (0.29; 95% CI 0.14-0.63) were significantly associated with YFV.

CONCLUSIONS

Preventive interventions other than YFV should be offered to older adults.

Evidence of malarial chemoprophylaxis among travellers who died from malaria: a systematic review and meta-analysis

BACKGROUND

Chemoprophylaxis is a prevention method for malaria during travel in malaria-endemic countries. This study aimed to collate and synthesize the evidence of malarial chemoprophylaxis among malaria death cases.

METHODS

Studies documenting malarial chemoprophylaxis related to malaria deaths were searched in PubMed, Scopus, MEDLINE, Embase, and CENTRAL until 3 July 2022. The pooled proportion of malarial chemoprophylaxis among death cases was synthesized using logit transformation and back transformation to a proportion performed using generalized linear mixed models. The pooled log odds ratio (log-OR) with a 95% confidence interval (CI) of malarial chemoprophylaxis in death cases compared to survivors were synthesized.

RESULTS

Fifty-eight studies were included in the systematic review and the meta-analysis. Of 602 pooled malaria death cases, the number of patients who took chemoprophylaxis was 187 (30%) (95% CI 22-40, P < 0.01, 58 studies), and those who took adequate chemoprophylaxis were 24 (5%) (95% CI 2-13, P < 0.01, 42 studies). A comparable log-OR of underwent chemoprophylaxis was observed between malaria death cases and survivors (P = 0.94, pooled log-OR: - 0.02, 95% CI - 0.46-0.42, I2: 0%, 17 studies). Similarly, a comparable log-OR of adequate chemoprophylaxis was identified between malaria death cases and survivors (P = 0.15, pooled log-OR: 0.83, 95% CI - 0.30-1.97, I2: 47.08%, 11 studies).

CONCLUSIONS

Among the studies where malarial chemoprophylaxis was reported, approximately 30% of malaria death cases had taken such prophylaxis. Notably, only 5% of these cases adhered fully or adequately to the recommended chemoprophylactic regimen. However, the analysis did not reveal a significant difference in the odds of malarial chemoprophylaxis between malaria death cases and survivors.

Epidemiological and clinical characteristics of imported falciparum malaria in the Republic of North Macedonia : A 13-year experience

BACKGROUND

Plasmodium falciparum is the leading cause of imported malaria and the most common cause of death in returning travellers.

AIM

To identify the main epidemiological and clinical characteristics of patients with imported falciparum malaria in the Republic of North Macedonia.

MATERIAL AND METHODS

Retrospectively analyzed were the epidemiological and clinical features of 34 patients with imported falciparum malaria who were diagnosed and treated at the university clinic for infectious diseases and febrile conditions in Skopje from 2010 to 2022. Malaria diagnosis was based on the microscopic detection of parasites in thick and thin blood smears.

RESULTS

All patients were male, with a median age of 36 years and a range of 22-60 years. Of the patients 33 (97.1%) acquired the disease in Sub-Saharan Africa. All patients except one stayed in endemic regions for work/business purposes. Chemoprophylaxis was completely applied in 4 (11.8%) patients. The median time of onset between the symptoms and diagnosis was 4 days, with a range of 1-12 days. Prevailing clinical manifestations were fever, chills, and splenomegaly in 100%, 94%, and 68% of patients, respectively. Severe malaria was noticed in 8 (23.5%) patients. In 5 (14.7%) patients the initial parasitemia was higher than 5%. On admission, thrombocytopenia, hyperbilirubinemia, and elevated alanine aminotransferase were registered in 94%, 58%, and 62% of patients, respectively. Out of the 33 patients with adequate follow-up, the outcome was favorable in 31 (93.9%).

CONCLUSION

In every febrile traveller returned from Africa, imported falciparum malaria should be an essential part of differential diagnostic considerations.

Malaria among the elderly in five communities of Osun East district, Southwest Nigeria: Prevalence and association with non-communicable diseases

Objective:

The level of immunity against pathogens decreases with old age. As a result, the elderly may be regarded to be at increased risk of malaria morbidity and fatality. There is paucity of studies on malaria among the elderly population in Osun East district, Southwest Nigeria. This study aimed to determine the prevalence of malaria and its association with medical comorbidities among the elderly.

Methods:

A descriptive cross-sectional study was carried out, which involved 972 adult residents of five communities in Osun State, who were selected using a multistage random sampling technique. Data was collected with aid of a structured questionnaire. The medical history of respondents and anthropometric measures were obtained. The presence of malaria parasitaemia in the respondents was determined by rapid diagnostic test (RDT). Appropriate descriptive and inferential analyses were done.

Results:

Out of the 972 respondents, 504 (51.9%) were 60 years and above. The overall prevalence of malaria RDT positivity was 4%. The positivity rate was higher among the elderly (4.6%) compared to those less than 60 years (3.4%), albeit not statistically significant ( p = 0.36). Among these elderlies, 52.6% and 16.1% used insecticide-treated nets and insecticide sprays, respectively. There was no association between the prevalence of malaria positivity and comorbid conditions, such as hypertension ( p = 0.37), overweight/obesity ( p = 0.77), or diabetes ( p = 0.15). Malaria positivity rate was also not significantly associated with the use of insecticide-treated nets ( p = 0.64) or insecticide sprays ( p = 0.45).

Conclusion:

The malaria positivity rate was higher among the elderly in the study area, although not statistically significant. The prevalence was not associated with comorbid medical conditions.

Prevalence, anti-malarial chemoprophylaxis and causes of deaths for severe imported malaria: A systematic review and meta-analysis

BACKGROUND

There are limited data regarding prevalence, anti-malarial chemoprophylaxis, and causes of death for severe imported malaria. Thus, we conducted a systematic review and meta-analysis to characterise these variables.

METHODS

We searched studies reporting deaths attributable to severe imported malaria. The following pooled prevalence rates were determined: 1) the pooled prevalence of severe malaria among patients with imported malaria, 2) the pooled prevalence of deaths among patients with severe imported malaria, 3) the pooled prevalence of anti-malarial chemoprophylaxis among patients with severe imported malaria, and 4) the causes of death among patients with severe imported malaria.

RESULTS

The search identified 52 studies that were mainly conducted in Europe (25, 48.1%), North America (16, 30.8%) and Asia (7, 13.5%). The pooled prevalence of severe imported malaria was 12.5% (95% confidence interval [CI] = 10.3%-14.6%, I² = 99.32%, 12393 severe cases/118325 imported cases). The pooled prevalence of deaths attributable to severe imported malaria was 5.1% (95% CI = 4.0%-6.2%, I² = 91.72%, 721 deaths/16310 severe cases). The pooled prevalence of adequate anti-malarial chemoprophylaxis among patients with severe imported malaria was 9.7% (95% CI = 6.5%-13.0%, I² = 89.9%, 203/2049 cases). The most common cause of death was multi-organ failure (12.3%).

CONCLUSION

The results highlighted the need for education and preventative measures for travellers, immigrants, or workers who plan to visit malaria-endemic areas to minimize the risk of severe disease or death.

Impact of Plasmodium vivax malaria on executive and cognitive functions in elderlies in the Brazilian Amazon

The exact path leading to cognitive impairment that goes beyond malaria is unclear, but it appears to be the result of interactive factors. Time of exposure to disease and recurrences are potentially major determinant variables. Cognitive impairment is described mainly in children, rarely in adults. The disease in high endemic areas usually does not affect elderlies, because of acquired immunity over time. However, this population is relatively more frequently sick in lower endemic areas, such as in the Amazon. This study assessed the effect of Plasmodium vivax malaria on the executive and cognitive functions of elderlies, in the Brazilian Amazon. A cohort study was conducted to evaluate executive and cognitive functions one week (T0), two months (T2) and eight months (T8) after the malaria episode. Mini-Mental State Examination (MMSE), Beck Depression Inventory II (BDI-II), Clock Drawing Test (CDT), Wechsler adult intelligence scale (WAIS-III), and Wisconsin Card Sorting Test (WCST) were used to assess executive and cognitive functions. One hundred-forty elderlies were enrolled (70 with P. vivax malaria and 70 without malaria). P. vivax malaria was associated with impairment of the executive and cognitive functions in elderlies for up to 8 months after acute P. vivax malaria. Prior history of malaria, recurrences and higher parasitemia were independently associated with various surrogates of executive and cognitive impairment. With the increase in life expectancy, elderlies living in malaria endemic areas will deserve more attention from health authorities, to guarantee improvement of their quality of life in the tropics.

Susceptibility to malaria during the prevention of re-establishment phase in Sri Lanka

Background

Sri Lanka eliminated malaria in November 2012 and was certified malaria-free by the World Health Organization (WHO) in September 2016 but is facing a challenge to prevent re-establishment of malaria. Influx of travellers from malarious countries and the presence of malaria vectors in formerly endemic areas make the country both receptive and vulnerable. Susceptibility to malaria, the predisposition of populations to be infected by malaria parasites, is influenced by biologic and generic factors such as the age-sex composition, socio economic status, and the migration history of the population. The aim of this study was to assess susceptibility to malaria during the prevention of re-establishment phase in Sri Lanka.

Methods

A national survey was conducted among 3454 households. A multistage cluster sampling technique was used to select the households. Susceptibility was assessed based on pre-defined variables by interviewing heads of households using an interviewer-administered questionnaire. Basic socio-demographic information, travel history, history of fever and past malaria infections in the preceding three years were collected. Data were analysed using SPSS version 20 package.

Results

The percentage of the population who had been overseas within the last 3 years in the urban sector (4.5%, n = 99) was higher than that of the rural (2.8%, n = 288) and estate sectors (0.2%, n = 2) (p < 0.001); it also declined with the wealth index up to the 4th quintile with a slight rise in the 5th quintile (p < 0.001). The likelihood of travel overseas was 1.75 times (95% CI: 1.38–2.22) higher for urban residents as compared rural estate residents; it was 1.46 times (95% CI: 1.16–1.92) higher for persons from the upper wealth index quintile as compared to persons from the 1st and 2nd quintiles after controlling for sex, age and area of residence. 177 persons had fever within the past 2 weeks of the survey. There was no association between presence of fever within the last 2 weeks and sector or travel abroad.

Conclusions

Urban residents, upper socioeconomic class persons and males are more likely to travel overseas and bring the parasite into the country. Social vulnerability and risk of re-establishment of malaria can be assessed by combining susceptibility with resilience and receptivity.

Epidemiology of Plasmodium falciparum Malaria and Risk Factors for Severe Disease in Hubei Province, China

This study aimed to describe the epidemiology of Plasmodium falciparum malaria and identify risk factors for severe disease in Hubei Province, China, using a case-based survey of retrospective data from 2013 to 2018. From 2013 to 2018, a total of 763 imported malaria cases were reported in Hubei Province; 69.2% (528/763) cases were caused by P. falciparum species. The proportion of malaria caused by P. falciparum increased from 66.7% in 2013 to 74.0% in 2018 (χ² = 21.378, P < 0.05). Plasmodium falciparum malaria was reported in 77 counties of Hubei Province. The majority of imported P. falciparum cases originated from Africa (98.9%, 522/528); 9.7% (51/528) of patients infected with P. falciparum developed severe malaria. Three deaths (case fatality rate: 0.6%) were related to imported P. falciparum malaria. Risk factors for severe malaria were being female (odds ratio [OR] = 3.593, 95% CI: 1.003-12.874), age ≥ 50 years (OR = 2.674, 95% CI: 1.269-5.634), > 3 days between symptom onset and diagnosis (OR = 2.383, 95% CI: 1.210-4.693), and the first-visit medical institution at the township level or lower (OR = 2.568, 95% CI: 1.344-4.908). Malaria prevention should be undertaken among high-risk groups, infection with P. falciparum should be detected early to prevent severe disease and death, and healthcare providers in health facilities at the township level should be trained on early recognition of malaria.

Severity of Plasmodium falciparum and Non-falciparum Malaria in Travelers and Migrants: A Nationwide Observational Study Over 2 Decades in Sweden

Background

The aim was to assess factors affecting disease severity in imported P. falciparum and non-falciparum malaria.

Methods

We reviewed medical records from 2793/3260 (85.7%) of all episodes notified in Sweden between 1995 and 2015 and performed multivariable logistic regression.

Results

Severe malaria according to WHO 2015 criteria was found in P. falciparum (9.4%), P. vivax (7.7%), P. ovale (5.3%), P. malariae (3.3%), and mixed P. falciparum episodes (21.1%). Factors associated with severe P. falciparum malaria were age <5 years and >40 years, origin in nonendemic country, pregnancy, HIV, region of diagnosis, and health care delay. Moreover, oral treatment of P. falciparum episodes with parasitemia ≥2% without severe signs at presentation was associated with progress to severe malaria with selected criteria. In non-falciparum, age >60 years, health care delay and endemic origin were identified as risk factors for severe disease. Among patients originating in endemic countries, a higher risk for severe malaria, both P. falciparum and non-falciparum, was observed among newly arrived migrants.

Conclusions

Severe malaria was observed in P. falciparum and non-falciparum episodes. Current WHO criteria for severe malaria may need optimization to better guide the management of malaria of different species in travelers and migrants in nonendemic areas.

Drug interactions with antimalarial medications in older travelers: a clinical guide

Increasingly older adults are traveling to international destinations with malaria as a present risk. Surveillance systems indicate that older adults are more likely to suffer severe complications from malaria. The role of health care providers in selecting an appropriate medication for chemoprophylaxis or treatment of malaria in adults becomes more difficult as older adults undergo physiologic changes that alter the pharmacokinetic and pharmacodynamic nature of medications potentially causing increased drug interactions, adverse events and altered drug action. A comprehensive literature search from 1970 to present, with a focus on the past 10 years, was conducted on drug interactions, pharmacokinetic and pharmacodynamic effects on antimalarials in adults. It was determined that due to pharmacodynamic and pharmacokinetic changes in older adults, especially renal and cardiovascular, special attention should be given to this population of travelers in order to minimize the likelihood of adverse events or altered drug efficacy. Antimalarial drug-disease interactions in older adults can occur more often due to QT prolongation, exacerbation of hypoglycemia, decreased renal elimination and decreased hepatic metabolism. Older antimalarials have well-documented drug-drug interactions. Tafenoquine, a new antimalarial, requires glucose-6-phosphate dehydrogenase screening like primaquine and monitoring of new potential drug interaction with MATE1 and OCT2 substrates. While drug-drug interactions in older travelers may occur more often as a result of polypharmacy, data did not indicate adverse reactions or decreased drug efficacy is greater compared with younger adults. Overall, with the exception of recently approved tafenoquine, much is known about antimalarial drug and disease interactions, but new drugs are always being approved, requiring travel health providers to understand the pharmacokinetics and pharmacodynamics of antimalarial drugs to predict the impact on safety and efficacy in travelers. This guide provides travel health providers with valuable insights on potential outcomes associated with drug interactions in adults and recommended monitoring or drug regimen modification.

Differential Expression of CD31 and Von Willebrand Factor on Endothelial Cells in Different Regions of the Human Brain: Potential Implications for Cerebral Malaria Pathogenesis

Cerebral microvascular endothelial cells (CMVECs) line the vascular system of the brain and are the chief cells in the formation and function of the blood brain barrier (BBB). These cells are heterogeneous along the cerebral vasculature and any dysfunctional state in these cells can result in a local loss of function of the BBB in any region of the brain. There is currently no report on the distribution and variation of the CMVECs in different brain regions in humans. This study investigated microcirculation in the adult human brain by the characterization of the expression pattern of brain endothelial cell markers in different brain regions. Five different brain regions consisting of the visual cortex, the hippocampus, the precentral gyrus, the postcentral gyrus, and the rhinal cortex obtained from three normal adult human brain specimens were studied and analyzed for the expression of the endothelial cell markers: cluster of differentiation 31 (CD31) and von-Willebrand-Factor (vWF) through immunohistochemistry. We observed differences in the expression pattern of CD31 and vWF between the gray matter and the white matter in the brain regions. Furthermore, there were also regional variations in the pattern of expression of the endothelial cell biomarkers. Thus, this suggests differences in the nature of vascularization in various regions of the human brain. These observations also suggest the existence of variation in structure and function of different brain regions, which could reflect in the pathophysiological outcomes in a diseased state.

Malaria prevention in the older traveller: a systematic review

Older travellers are at higher risk of malaria-related morbidity and mortality compared with younger people. Yet, prevention of malaria in this specific group of travellers is a long-standing issue in travel medicine. The aim of this research was to synthetize the existing evidence about this important topic, highlighting older travellers' attitudes and practises toward malaria prevention. Searches were performed on PubMed, Embase, EuropePMC, Web of Science, WHOLIS and LILACS databases for relevant studies reporting malaria prevention measures in older travellers. To measure malaria prevention in the older traveller population, the main information outcomes were obtained from the ABCD framework that included travellers' 'Awareness' towards pre-travel health advice, their utilisation of 'Bite-prevention measures' and adherence to 'Chemoprophylaxis'. Data on 'Diagnosis'-related outcomes were excluded for not being measures of malaria prevention. Three evaluators independently selected studies, extracted data and assessed the quality of the included articles. The research protocol was registered with PROSPERO (protocol number CRD42019124202). Out of the 899 titles and abstracts screened, 13 articles were included in this review synthesis. These studies included a wide range of interventions for malaria prevention: no relevant differences in pre-travel healthcare attendance were found depending on age; older travellers were found to be less likely to comply with bite-prevention measures; three high-quality studies reported that adherence to chemoprophylaxis significantly increased with age, while three studies did not find age-related differences in travellers' adherence. Overall, prevention of malaria in the older traveller has received limited attention from the scientific community. Older travellers seem to be less likely to comply with bite-prevention measures, but there was high heterogeneity across the reports. This population group demands particular attention and tailored health advice before travelling to malaria endemic areas. More research is required on how to improve malaria prevention in the older traveller.

Risk factors of severe imported malaria in Anhui province, China

We aimed to determine risk factors for developing severe illness in patients infected with imported Plasmodium falciparum, and identify factors that can be implemented in preventive public health actions. Data of patients in Anhui province were collected from the China Information System for Disease Control and Prevention and Information System for Parasitic Disease Control and Prevention from 2012 to 2018. Epidemiological characteristics, clinical severity, and preventive measures were analyzed using descriptive statistics. Risk factors for severe malaria were identified by logistic regression. During the study period, 8.01% (53/662) of patients infected with P. falciparum developed severe malaria; the annual severe incidence rate varied from 5.93% to 10.77% and the fatality rate was 0.6%. Two models were built to analyze the delay from symptom onset to treatment; one analyzed data by stage, whereas the other analyzed data combined from all stages. In model 1, multivariate analysis identified misdiagnosis at first medical visit and patient delay as risk factors for severe malaria (odds ratio: 3.108 and 3.385, respectively, all p < 0.01). In model 2, overall delay was a significant factor of severe malaria onset (odds ratio: 4.719, p = 0.000). In both models, patients with a history of previous infection had a significantly reduced risk of developing severe malaria; high parasitemia (≥2.5%) was associated with an increased risk of severe infection. Delay between symptom onset and treatment was an important cause for development of severe disease in Anhui province. Measures to reduce delays should be used and implemented in preventive public health actions.

Management of severe imported malaria in adults

Severe malaria accounts for approximately 10% of all cases of imported malaria in France; cases are mainly due to Plasmodium falciparum, while other Plasmodium species are possible but uncommon (P. vivax, P. knowlesi, P. malariae, and P. ovale). On the basis of WHO criteria for endemic areas, the French criteria defining severe imported malaria in adults have been progressively adapted to the European healthcare level. Management of severe imported malaria is a diagnostic and treatment emergency and must be initially conducted in the intensive care unit. Anti-infective treatment is now based on intravenous artesunate, which must be available in every hospital of the country likely to receive severe imported malaria patients. Intravenous quinine is thus used as a second-line treatment and is restricted to limited indications. Critical care management of organ failure is essential, particularly in patients presenting with very severe malaria. To date, no adjunctive therapy (including exchange transfusion) has demonstrated clear beneficial effects.

Prise en charge du paludisme grave d’importation de l’adulte

En France, le paludisme grave d’importation concerne environ 12 à 14 % des accès palustres et implique très majoritairement Plasmodium falciparum. À partir de la définition du paludisme grave de l’Organisation mondiale de la santé utilisée en zone d’endémie palustre, la définition française du paludisme grave d’importation de l’adulte a été adaptée aux données et au contexte européens. La prise en charge du paludisme grave est une urgence diagnostique et thérapeutique qui doit être réalisée initialement en réanimation. Le traitement curatif du paludisme grave d’importation repose maintenant sur l’artésunate intraveineux (IV) qui doit être disponible dans chaque hôpital susceptible de recevoir ces patients. Dès lors, la quinine IV devient un traitement de seconde ligne réservé à quelques circonstances. La prise en charge symptomatique des défaillances d’organes est primordiale, notamment au cours des formes les plus sévères. Enfin, aucun traitement adjuvant n’a prouvé, à ce jour, son efficacité en pratique clinique.

Obesity and Diabetes as Risk Factors for Severe Plasmodium falciparum Malaria: Results From a Swedish Nationwide Study

BACKGROUND

Noncommunicable diseases and obesity are increasing in prevalence globally, also in populations at risk of malaria. We sought to investigate if comorbidity, in terms of chronic diseases and obesity, is associated with severe Plasmodium falciparum malaria.

METHODS

We performed a retrospective observational study in adults (≥18 years of age) diagnosed with malaria in Sweden between January 1995 and May 2015. We identified cases through the surveillance database at the Public Health Agency of Sweden and reviewed clinical data from 18 hospitals. Multivariable logistic regression was used to assess associations between comorbidities and severe malaria.

RESULTS

Among 937 adults (median age, 37 years; 66.5% were male), patients with severe malaria had higher prevalence of chronic diseases (28/92 [30.4%]) compared with nonsevere cases (151/845 [17.9%]) (P = .004). Charlson comorbidity score ≥1 was associated with severe malaria (adjusted odds ratio [aOR], 2.63 [95% confidence interval {CI}, 1.45-4.77), as was diabetes among individual diagnoses (aOR, 2.98 [95% CI, 1.25-7.09]). Median body mass index was higher among severe (29.3 kg/m2) than nonsevere cases (24.7 kg/m2) (P < .001). Obesity was strongly associated with severe malaria, both independently (aOR, 5.58 [95% CI, 2.03-15.36]) and in combination with an additional metabolic risk factor (hypertension, dyslipidemia, or diabetes) (aOR, 6.54 [95% CI, 1.87-22.88]). The associations were observed among nonimmune travelers as well as immigrants from endemic areas.

CONCLUSIONS

Comorbidities, specifically obesity and diabetes, are previously unidentified risk factors for severe malaria in adults diagnosed with P. falciparum. Noncommunicable diseases should be considered in the acute management and prevention of malaria.

Effects of Aging on Parasite Biomass, Inflammation, Endothelial Activation, Microvascular Dysfunction and Disease Severity in Plasmodium knowlesi and Plasmodium falciparum Malaria

Background

In populations pauci-immune to malaria, risk of severe malaria increases with age. This is particularly apparent in Plasmodium knowlesi malaria. However, pathophysiological mechanisms underlying knowlesi malaria, and of the age-related increase in risk of severe malaria in general, are poorly understood.

Methods

In Malaysian patients aged ≥12 years with severe (n = 47) and nonsevere (n = 99) knowlesi malaria, severe (n = 21) and nonsevere (n = 109) falciparum malaria, and healthy controls (n = 50), we measured parasite biomass, systemic inflammation (interleukin 6 [IL-6]), endothelial activation (angiopoietin-2), and microvascular function, and evaluated the effects of age.

Results

Plasmodium knowlesi parasitemia correlated with age (Spearman's correlation coefficient [rs] = 0.36; P < .0001). In knowlesi malaria, IL-6, angiopoietin-2, and microvascular dysfunction were increased in severe compared to nonsevere disease, and all correlated with age, independent of parasitemia. In falciparum malaria, angiopoietin-2 increased with age, independent of parasite biomass (histidine-rich protein 2 [HRP2]). Independent risk factors for severe malaria included parasitemia and angiopoietin-2 in knowlesi malaria, and HRP2, angiopoietin-2, and microvascular dysfunction in falciparum malaria.

Conclusions

Parasite biomass, endothelial activation, and microvascular dysfunction are associated with severe disease in knowlesi malaria and likely contribute to pathogenesis. The association of each of these processes with aging may account for the greater severity of malaria observed in older adults in low-endemic regions.

Redefining priorities towards graded travel-related infectious disease research

Our knowledge of the health problems and infections encountered by international travellers has evolved considerably in the past decades. The growth of global networks such as the GeoSentinel Surveillance network, TropNet Europe, EuroTravNet and networks based in North America have provided valuable information on the frequency of a wide array of travel-related diseases and accidents, including details on the destination of travel and trends over time. The information gained from these network studies has provided important data for the practice of travel medicine and in some instances for the development of practice guidelines. However, network data due to a lack of denominators usually cannot serve as a basis for a GRADE approach to guideline development. Although epidemiological network studies will continue to serve an important role in travel medicine we encourage an additional strong focus towards translational scientific research questions and towards the broader use of novel techniques to obtain more accurate epidemiological analyses to address the many unanswered questions in our field.

Comparing imported malaria in adults and children presenting to an Italian teaching hospital: A 10-year retrospective study

BACKGROUND

Malaria is not endemic in Italy, but it still represents an important threat to the travelers' health. With this study we wanted to compare the characteristics of imported malaria between adults and children.

METHOD

This retrospective observational study includes all patients admitted to the Infectious Diseases Unit and in the Pediatric Department of Padua (Italy), and discharged with a diagnosis of malaria from 2005 to 2015. The variables considered are epidemiological and clinical.

RESULTS

172 cases of imported malaria were studied (124 adults and 48 children), P. falciparum was responsible for 90,7% of the cases, and was contracted mostly in Africa (96,5%), especially by foreigners visiting friends and relatives (VFR). Chemoprophylaxis was adopted only by few patients. 93% of all the patients developed the uncomplicated malaria, but pediatric patients had severe malaria significantly more often than adults (OR = 4,06, p = 0,015). Children also had significantly lower hemoglobin levels and higher parasitemia. The drugs used to treat the two groups were substantially different, but both had a good overall outcome.

CONCLUSIONS

In order to reduce the risk of imported malaria, educational actions should target potential VFR travelers, and they should underline the different risk of severe malaria in adults and children. A further implementation of the recommended therapies could improve the patients' outcome.

Influence of host factors and parasite biomass on the severity of imported Plasmodium falciparum malaria

OBJECTIVES

Imported malaria in France is characterized by various clinical manifestations observed in a heterogeneous population of patients such as travelers/expatriates and African migrants. In this population, host factors and parasite biomass associated with severe imported malaria are poorly known.

METHODS

From data collected by the Centre National de Référence du Paludisme, we identified epidemiological, demographic and biological features including parasite biomass and anti-plasmodial antibody levels (negative, positive and strongly positive serology) associated with different disease severity groups (very severe, moderately severe, and uncomplicated malaria) in 3 epidemiological groups (travelers/expatriates, first- and second-generation migrants).

RESULTS

Age, ethnicity, absence of prior infection with P. falciparum, antibody levels, plasma PfHRP2 levels, total and circulating parasite biomass were related to severe malaria onset. Sequestered parasite biomass tended to be increased in very severe malaria, and was strongly correlated to the antibody level of the host.

CONCLUSIONS

Prior exposure to P. falciparum is associated with high anti-plasmodial antibody levels which influence clinical presentation of imported malaria and its correlated circulating and sequestered parasite burden.

Severe malaria in Europe: an 8-year multi-centre observational study

Background

Malaria remains one of the most serious infections for travellers to tropical countries. Due to the lack of harmonized guidelines a large variety of treatment regimens is used in Europe to treat severe malaria.

Methods

The European Network for Tropical Medicine and Travel Health (TropNet) conducted an 8-year, multicentre, observational study to analyse epidemiology, treatment practices and outcomes of severe malaria in its member sites across Europe. Physicians at participating TropNet centres were asked to report pseudonymized retrospective data from all patients treated at their centre for microscopically confirmed severe Plasmodium falciparum malaria according to the 2006 WHO criteria.

Results

From 2006 to 2014 a total of 185 patients with severe malaria treated in 12 European countries were included. Three patients died, resulting in a 28-day survival rate of 98.4%. The majority of infections were acquired in West Africa (109/185, 59%). The proportion of patients treated with intravenous artesunate increased from 27% in 2006 to 60% in 2013. Altogether, 56 different combinations of intravenous and oral drugs were used across 28 study centres. The risk of acute renal failure (36 vs 17% p = 0.04) or cerebral malaria (54 vs 20%, p = 0.001) was significantly higher in patients ≥60 years than in younger patients. Respiratory distress with the need for mechanical ventilation was significantly associated with the risk of death in the study population (13 vs 0%, p = 0.001). Post-artemisinin delayed haemolysis was reported in 19/70 (27%) patients treated with intravenous artesunate.

Conclusion

The majority of patients with severe malaria in this study were tourists or migrants acquiring the infection in West Africa. Intravenous artesunate is increasingly used for treatment of severe malaria in many European treatment centres and can be given safely to European patients with severe malaria. Patients treated with intravenous artesunate should be followed up to detect and manage late haemolytic events.

UK malaria treatment guidelines 2016

1.Malaria is the tropical disease most commonly imported into the UK, with 1300-1800 cases reported each year, and 2-11 deaths. 2. Approximately three quarters of reported malaria cases in the UK are caused by Plasmodium falciparum, which is capable of invading a high proportion of red blood cells and rapidly leading to severe or life-threatening multi-organ disease. 3. Most non-falciparum malaria cases are caused by Plasmodium vivax; a few cases are caused by the other species of plasmodium: Plasmodium ovale, Plasmodium malariae or Plasmodium knowlesi. 4. Mixed infections with more than one species of parasite can occur; they commonly involve P. falciparum with the attendant risks of severe malaria. 5. There are no typical clinical features of malaria; even fever is not invariably present. Malaria in children (and sometimes in adults) may present with misleading symptoms such as gastrointestinal features, sore throat or lower respiratory complaints. 6. A diagnosis of malaria must always be sought in a feverish or sick child or adult who has visited malaria-endemic areas. Specific country information on malaria can be found at http://travelhealthpro.org.uk/. P. falciparum infection rarely presents more than six months after exposure but presentation of other species can occur more than a year after exposure. 7. Management of malaria depends on awareness of the diagnosis and on performing the correct diagnostic tests: the diagnosis cannot be excluded until more than one blood specimen has been examined. Other travel related infections, especially viral haemorrhagic fevers, should also be considered. 8. The optimum diagnostic procedure is examination of thick and thin blood films by an expert to detect and speciate the malarial parasites. P. falciparum and P. vivax (depending upon the product) malaria can be diagnosed almost as accurately using rapid diagnostic tests (RDTs) which detect plasmodial antigens. RDTs for other Plasmodium species are not as reliable. 9. Most patients treated for P. falciparum malaria should be admitted to hospital for at least 24 h as patients can deteriorate suddenly, especially early in the course of treatment. In specialised units seeing large numbers of patients, outpatient treatment may be considered if specific protocols for patient selection and follow up are in place. 10. Uncomplicated P. falciparum malaria should be treated with an artemisinin combination therapy (Grade 1A). Artemether-lumefantrine (Riamet(®)) is the drug of choice (Grade 2C) and dihydroartemisinin-piperaquine (Eurartesim(®)) is an alternative. Quinine or atovaquone-proguanil (Malarone(®)) can be used if an ACT is not available. Quinine is highly effective but poorly-tolerated in prolonged treatment and should be used in combination with an additional drug, usually oral doxycycline. 11. Severe falciparum malaria, or infections complicated by a relatively high parasite count (more than 2% of red blood cells parasitized) should be treated with intravenous therapy until the patient is well enough to continue with oral treatment. Severe malaria is a rare complication of P. vivax or P. knowlesi infection and also requires parenteral therapy. 12. The treatment of choice for severe or complicated malaria in adults and children is intravenous artesunate (Grade 1A). Intravenous artesunate is unlicensed in the EU but is available in many centres. The alternative is intravenous quinine, which should be started immediately if artesunate is not available (Grade 1A). Patients treated with intravenous quinine require careful monitoring for hypoglycemia. 13. Patients with severe or complicated malaria should be managed in a high-dependency or intensive care environment. They may require haemodynamic support and management of: acute respiratory distress syndrome, disseminated intravascular coagulation, acute kidney injury, seizures, and severe intercurrent infections including Gram-negative bacteraemia/septicaemia. 14. Children with severe malaria should also be treated with empirical broad spectrum antibiotics until bacterial infection can be excluded (Grade 1B). 15. Haemolysis occurs in approximately 10-15% patients following intravenous artesunate treatment. Haemoglobin concentrations should be checked approximately 14 days following treatment in those treated with IV artemisinins (Grade 2C). 16. Falciparum malaria in pregnancy is more likely to be complicated: the placenta contains high levels of parasites, stillbirth or early delivery may occur and diagnosis can be difficult if parasites are concentrated in the placenta and scanty in the blood. 17. Uncomplicated falciparum malaria in the second and third trimester of pregnancy should be treated with artemether-lumefantrine (Grade 2B). Uncomplicated falciparum malaria in the first trimester of pregnancy should usually be treated with quinine and clindamycin but specialist advice should be sought. Severe malaria in any trimester of pregnancy should be treated as for any other patient with artesunate preferred over quinine (Grade 1C). 18. Children with uncomplicated malaria should be treated with an ACT (artemether-lumefantrine or dihydroartemisinin-piperaquine) as first line treatment (Grade 1A). Quinine with doxycycline or clindamycin, or atovaquone-proguanil at appropriate doses for weight can also be used. Doxycycline should not be given to children under 12 years. 19. Either an oral ACT or chloroquine can be used for the treatment of non-falciparum malaria. An oral ACT is preferred for a mixed infection, if there is uncertainty about the infecting species, or for P. vivax infection from areas where chloroquine resistance is common (Grade 1B). 20. Dormant parasites (hypnozoites) persist in the liver after treatment of P. vivax or P. ovale infection: the only currently effective drug for eradication of hypnozoites is primaquine (1A). Primaquine is more effective at preventing relapse if taken at the same time as chloroquine (Grade 1C). 21. Primaquine should be avoided or given with caution under expert supervision in patients with Glucose-6-phosphate dehydrogenase deficiency (G6PD), in whom it may cause severe haemolysis. 22. Primaquine (for eradication of P. vivax or P. ovale hypnozoites) is contraindicated in pregnancy and when breastfeeding (until the G6PD status of child is known); after initial treatment for these infections a pregnant woman should take weekly chloroquine prophylaxis until after delivery or cessation of breastfeeding when hypnozoite eradication can be considered. 23. An acute attack of malaria does not confer protection from future attacks: individuals who have had malaria should take effective anti-mosquito precautions and chemoprophylaxis during future visits to endemic areas.

Epidemiology and clinical features of imported malaria in East London

BACKGROUND

Malaria is the most common imported tropical disease in the United Kingdom (UK). The overall mortality is low but inter-regional differences have been observed.

METHODS

We conducted a 2-year retrospective review of clinical and laboratory records of patients with malaria attending three acute hospitals in East London from 1 April 2013 through 31 March 2015. Epidemiological and clinical characteristics of imported malaria were described and risk factors associated with severe falciparum malaria were explored.

RESULTS

In total, 133 patients with laboratory-confirmed malaria were identified including three requiring critical care admission but no deaths. The median age at presentation was 41 years (IQR 30-50). The majority of patients were males (64.7%, 86/133) and had Black or Black British ethnicity (67.5%, 79/117). West Africa was the most frequent region of travel (70.4%, 76/108). Chemoprophylaxis use was poor (25.3%, 20/79). The interval between arriving in the UK and presenting to hospital was short (median 10 days; IQR 5-15.5, n = 84). July-September was the peak season of presentation (34.6%, 46/133). Plasmodium falciparum was the commonest species (76.7%, 102/133) and 31.4% (32/102) of these patients had parasitaemia >2%. Severe falciparum malaria was documented in 36.3% (37/102) of patients and the October-March season presentation was associated with an increased risk of severity (OR 3.00; 95% CI 1.30-6.93). Black patients appeared to have reduced risk of severe falciparum malaria (OR 0.46; 95% CI 0.16-1.35) but this was not statistically significant. HIV sero-status was determined in only 27.1% (36/133) of cases. Only 8.5% (10/117) of all malaria patients were treated as outpatients.

CONCLUSION

Clinicians need to raise awareness on malaria prevention strategies, improve rates of HIV testing in tropical travellers, and familiarise themselves with ambulatory management of malaria. The relationship between season of presentation, ethnicity and severity of falciparum malaria should be explored further.

Malaria in the returning older traveler

BACKGROUND

Increased co-morbidities and physiological changes mean older patients may be at higher risk of adverse outcomes from certain imported illnesses. One of the most commonly diagnosed imported infections in returning travelers is malaria. Increasing age is strongly and independently associated with increasing morbidity and mortality from malaria. Delayed diagnosis leads to higher risks of poor clinical outcomes in older patients presenting with malaria. The objective of this study was to quantify malaria presentations in older patients as a percentage of total malaria presentations, compare length of hospital stay (LOS) between the older and younger cohort, and to describe medical co-morbidities, length of time to diagnosis and factors contributing to delayed diagnosis and increased LOS in the older cohort.

METHODS

A retrospective cohort study was undertaken in two university hospitals of all patients aged 65 years or older presenting with malaria from 2002-2012. A national hospital inpatient database was used to identify patients of all ages with a discharge diagnosis of malaria over this ten year period, and quantify LOS in those aged <65 and those aged 65 years or older. The case-notes for all of the older cohort were reviewed.

RESULTS

There were a total of 203 cases, 12 of whom were aged ≥65 years (5.9 %- total). Median time to diagnosis in this older group was two days (range 0-35), median LOS was eight days (range 1-77), compared to a median LOS of three days in those aged <65 years. All patients aged ≥65 years presented with fever. Travel history was documented in only 6/12 charts, and 11/12 had two or more co-morbid illnesses. Six of the 12 patients were not diagnosed or treated within 48 h of presentation.

CONCLUSIONS

This case series highlights the need for appropriate history-taking and timely diagnosis of the older traveler returning with fever, as delayed diagnosis and treatment can contribute to prolonged hospital stay and increased morbidity. With increasing numbers of older travelers, physicians must remain vigilant to the presence of imported illnesses, particularly malaria, in older patients with unexplained fever.

The elderly, the young and the pregnant traveler -- A retrospective data analysis from a large Swiss Travel Center with a special focus on malaria prophylaxis and yellow fever vaccination

BACKGROUND

Vulnerable individuals such as elderly, children/adolescents and pregnant/breastfeeding women increasingly travel overseas. We describe the travel and vaccination patterns of these groups at the largest Travel Clinic in Switzerland especially focusing on travel to yellow fever and malaria-endemic countries, and yellow fever vaccination (YFV) and malaria medications.

METHOD

An analysis of pre-travel visits between 2010 and 2012 at the Travel Clinic of the University of Zurich, was performed assessing differences between the elderly, young and middle-aged travelers as well as between pregnant/breastfeeding and other female travelers.

RESULTS

Overall, the vulnerable groups did not differ from other travelers regarding their travel patterns. YFV was the most often administered vaccine to elderly travelers; half of them received it for the first time. More than 30% of children/adolescents received YFV, but no child below six months was vaccinated. 80% of young travelers and a similar percentage of pregnant women went to malaria-endemic regions. Twenty-five pregnant/breastfeeding women traveled to YF endemic areas.

CONCLUSIONS

Travel patterns of vulnerable travelers are comparable to those of other travelers. In view of the limited data on malaria medications and precautions against YFV during pregnancy and at the extreme ages of life, giving travel advice to these groups is challenging.

Intravenous Artesunate for the Treatment of Severe and Complicated Malaria in the United States: Clinical Use Under an Investigational New Drug Protocol

BACKGROUND

Quinidine gluconate, the only U.S. Food and Drug Administration-approved treatment for life-threatening malaria in the United States, has a problematic safety profile and is often unavailable in hospitals.

OBJECTIVE

To assess the safety and clinical benefit of intravenous artesunate as an alternative to quinidine.

DESIGN

Retrospective case series.

SETTING

U.S. hospitals.

PATIENTS

102 patients aged 1 to 72 years (90% adults; 61% men) with severe and complicated malaria. Patients received 4 weight-based doses of intravenous artesunate (2.4 mg/kg) under a treatment protocol implemented by the Centers for Disease Control and Prevention between January 2007 and December 2010. At baseline, 35% had evidence of cerebral malaria, and 17% had severe hepatic impairment. Eligibility required the presence of microscopically confirmed malaria, need for intravenous treatment, and an impediment to quinidine.

MEASUREMENTS

Clinical and laboratory data from each patient's hospital records were abstracted retrospectively, including information from baseline through a maximum 7-day follow-up, and presented before a physician committee to evaluate safety and clinical benefit outcomes.

RESULTS

7 patients died (mortality rate, 6.9%). The most frequent adverse events were anemia (65%) and elevated hepatic enzyme levels (49%). All deaths and most adverse events were attributed to the severity of malaria. Patients' symptoms generally improved or resolved within 3 days, and the median time to discharge from the intensive care unit was 4 days, even for patients with severe liver disease or cerebral malaria. More than 100 concomitant medications were used, with no documented drug-drug interactions.

LIMITATION

Potential late-presenting safety issues might occur outside the 7-day follow-up.

CONCLUSION

Artesunate was a safe and clinically beneficial alternative to quinidine.

Intravenous Artesunate Reduces Parasite Clearance Time, Duration of Intensive Care, and Hospital Treatment in Patients With Severe Malaria in Europe: The TropNet Severe Malaria Study

Intravenous artesunate improves survival in severe malaria, but clinical trial data from nonendemic countries are scarce. The TropNet severe malaria database was analyzed to compare outcomes of artesunate vs quinine treatment. Artesunate reduced parasite clearance time and duration of intensive care unit and hospital treatment in European patients with imported severe malaria.

Clinical, geographical, and temporal risk factors associated with presentation and outcome of vivax malaria imported into the United Kingdom over 27 years: observational study

OBJECTIVE

To examine temporal and geographical trends, risk factors, and seasonality of imported vivax malaria in the United Kingdom to inform clinical advice and policy.

DESIGN

Observational study.

SETTING

National surveillance data from the UK Public Health England Malaria Reference Laboratory, data from the International Passenger Survey, and international climactic data.

PARTICIPANTS

All confirmed and notified cases of malaria in the UK (n=50,187) from 1987 to 2013, focusing on 12,769 cases of vivax malaria.

MAIN OUTCOME MEASURES

Mortality, sociodemographic details (age, UK region, country of birth and residence, and purpose of travel), destination, and latency (time between arrival in the UK and onset of symptoms).

RESULTS

Of the malaria cases notified, 25.4% (n=12,769) were due to Plasmodium vivax, of which 78.6% were imported from India and Pakistan. Most affected patients (53.5%) had travelled to visit friends and relatives, and 11.1% occurred in tourists. Imported P vivax is concentrated in areas with large communities of south Asian heritage. Overall mortality was 7/12,725 (0.05%), but with no deaths in 9927 patients aged under 50 years. Restricting the analysis to those aged more than 50 years, mortality was 7/2798 (0.25%), increasing to 4/526 (0.76%) (adjusted odds ratio 32.0, 95% confidence interval 7.1 to 144.0, P<0.001) in those aged 70 years or older. Annual notifications decreased sharply over the period, while traveller numbers between the UK and South Asia increased. The risk of acquiring P vivax from South Asia was year round but was twice as high from June to September (40 per 100,000 trips) compared with the rest of the year. There was strong seasonality in the latency from arrival in the UK to presentation, significantly longer in those arriving in the UK from South Asia from October to March (median 143 days) versus those arriving from April to September (37 days, P<0.001).

CONCLUSIONS

Travellers visiting friends and family in India and Pakistan are most at risk of acquiring P vivax, and older patients (especially those >70 years) are most at risk of dying; these groups should be targeted for advice before travelling. The risk of acquiring vivax malaria is year round but higher during summer monsoons, masked by latency. The latency of time to clinical presentation of imported vivax malaria in the UK is highly seasonal; seasonal latency has implications for pretravel advice but also for the control of malaria in India and Pakistan. A reduced incidence of vivax malaria in travellers may mean further areas of South Asia can be considered not to need malaria chemoprophylaxis.

Imported malaria in portugal 2000-2009: a role for hospital statistics for better estimates and surveillance

Background. Although eradicated in Portugal, malaria keeps taking its toll on travelers and migrants from endemic countries. Disease notification is mandatory but is compromised by underreporting. Methods. A retrospective study on malaria hospitalizations for 10 consecutive years (2000–2009) was conducted. Data on hospitalizations and notifications were obtained from Central Administration of Health System and Health Protection Agency, respectively. For data selection ICD-9 CM and ICD-10 were used: codes 084^*, 647.4, and B50–B54. Variables were gender, age, agent and origin of infection, length of stay (LOS), lethality, and comorbidities. Analysis included description, hypothesis testing, and regression. Results. There were 2003 malaria hospitalizations and 480 notified hospitalized cases, mainly in young male adults. P. falciparum was the main agent of infection acquired mainly in sub-Saharan Africa. Lethality was 1.95% and mean LOS was 8.09 days. Older age entailed longer LOS and increased lethality. Discussion. From 2000 to 2009, there were 2003 malaria hospitalizations with decreasing annual incidence, these numbers being remarkably higher than those notified. The national database of diagnosis related groups, reflecting hospitalizations on NHS hospitals, may be an unexplored complementary source for better estimates on imported malaria.

Duration of residency in a non-endemic area and risk of severe malaria in African immigrants

In malaria-endemic areas, adults very rarely succumb to severe malaria, suggesting that immunity to severe disease is life-long under conditions of repeated exposure. To what extent this protection persists in the absence of exposure remains to be established. The aim of this study was to assess whether duration of residency in a malaria-free country affects the risk for severe malaria in immigrants originating from sub-Saharan Africa. We conducted a retrospective chart review of 948 cases of malaria diagnosed in Stockholm, Sweden in 1995-2013. Among 501 adult patients with Plasmodium falciparum (315 of endemic origin and 186 of non-endemic origin, mainly Sweden), 41 (8.2%) had severe malaria according to WHO criteria (including 5% with parasitaemia), 22 (4.4%) had factors prognostic of poor outcome, and 35 (7.0%) were admitted to intensive care. Overall, patient origin did not affect the odds of severe malaria, according to any of these definitions. However, when the immigrants were stratified with regard to their duration of residency in Sweden, the risk of factors prognostic for poor outcome was associated with duration of prior residency in a malaria-free country among patients of endemic origin (p 0.02), and immigrants who had lived for ≥ 15 years in Sweden had a similar risk as non-immune travellers. The results of this explorative study suggest that, although immunity to severe malaria is maintained for several years in African adults, this protection might be lost with time without repeated re-exposure. A larger study, preferably including multiple centres, will be needed to confirm our findings.

Cytokine network in adults with falciparum Malaria and HIV-1: increased IL-8 and IP-10 levels are associated with disease severity

Background

Co-infection with malaria and HIV increases the severity and mortality of both diseases, but the cytokine responses related to this co-infection are only partially characterised. The aim of this study was to explore cytokine responses in relation to severity and mortality in malaria patients with and without HIV co-infection.

Methods

This was a prospective cross-sectional study. Clinical data and blood samples were collected from adults in Mozambique. Plasma was analysed for 21 classical pro- and anti-inflammatory cytokines, including interleukins, interferons, and chemokines.

Results

We included 212 in-patients with fever and/or suspected malaria and 56 healthy controls. Falciparum malaria was diagnosed in 131 patients, of whom 70 were co-infected with HIV-1. The malaria patients had marked increases in their cytokine responses compared with the healthy controls. Some of these changes, particularly interleukin 8 (IL-8) and interferon-γ-inducing protein 10 (IP-10) were strongly associated with falciparum malaria and disease severity. Both these chemokines were markedly increased in patients with falciparum malaria as compared with healthy controls, and raised levels of IL-8 and IP-10 were associated with increased disease severity, even after adjusting for relevant confounders. For IL-8, particularly high levels were found in malaria patients that were co-infected with HIV and in those who died during hospitalization.

Interpretations

Our findings underscore the complex role of inflammation during infection with P. falciparum, and suggest a potential pathogenic role for IL-8 and IP-10. However, the correlations do not necessarily mean any causal relationship, and further both clinical and mechanistic research is necessary to elucidate the role of cytokines in pathogenesis and protection during falciparum malaria.

The burden of imported malaria in Portugal 2003 to 2012

Increasing international travel and expatriation to sub-Saharan countries where malaria is endemic has raised public health concerns about the burden of imported malaria cases in Portugal. From 2009 to 2012, there was a 60% increase in malaria hospitalizations, contradicting the declining trend observed since 2003. Older age was associated with longer length of stay in hospital and higher lethality.

Increased severity and mortality in adults co-infected with malaria and HIV in Maputo, Mozambique: a prospective cross-sectional study

Background

Co-infection with falciparum malaria and HIV-1 increases the severity and mortality of both infections in unstable malaria-transmission areas. In contrast, in stable transmission areas, HIV co-infection increases the severity of both infections but has not been found to influence malaria mortality.

Methods

In a prospective cross-sectional study, clinical and laboratory data were consecutively collected for all adults admitted with fever and/or suspected malaria to the medical department of the Central Hospital of Maputo, Mozambique, during two malaria seasons from January 2011. Malaria and HIV PCRs were performed, and risk factors for fatal outcomes were analysed. The impact of HIV on the clinical presentation and mortality of malaria was assessed.

Findings

A total of 212 non-pregnant adults with fever and/or suspected malaria and 56 healthy controls were included in the study. Of the 131 patients with confirmed falciparum malaria, 70 were co-infected with HIV-1. The in-hospital mortality of the co-infected patients was 13.0% (9/69) compared with 1.7% (1/59) in the patients without HIV (p = 0.018). Malaria severity (p = 0.016) and co-infection with HIV (p = 0.064) were independent risk factors for death although the association with HIV did not reach statistical significance. The co-infected patients had significantly more frequent respiratory distress, bleeding disturbances, hypoglycaemia, liver and renal failure and high malaria parasitemia compared with the patients with malaria alone.

Interpretations

HIV co-infection is associated with increased disease severity in and mortality from malaria in an area of stable malaria transmission. This finding was not observed earlier and should motivate doctors working in malaria-endemic areas to consider early HIV testing and a closer follow-up of patients with malaria and HIV co-infection.

Imported Plasmodium falciparum malaria in Istanbul, Turkey: risk factors for severe course and mortality

We describe the epidemiological, clinical features and risk factors for the morbidity and mortality of imported Plasmodium falciparum malaria cases during the last 10 years in Istanbul, Turkey. The epidemiological, clinical and laboratory data of cases in six tertiary care hospitals in Istanbul between 2002 and 2012 were analysed. Seventy patients (65 males, five females; median age 37; range: 14-84) were included. Sixty-five (93%) patients had travelled to African countries and the remaining five to other malarious countries. Seventeen (24%) had a history of previous malarial episodes; eight (13%) developed recrudescence during the first month; 22 (31%), 17 (24%), 20 (29%) and three (4%) cases had cerebral malaria, cholestatic icterus, malarial hepatitis and respiratory distress syndrome on admission, respectively. Six of 12 patients with severe falciparum malaria died. Clinically, the presence of alteration in mental status, icterus, hypoglycaemia, disseminated intravascular coagulation and malarial hepatitis were statistically significant for the development of severe malaria and mortality. Recrudescence should not be forgotten, especially in uncomplicated cases.

Clinical aspects of uncomplicated and severe malaria

The first symptoms of malaria, common to all the different malaria species, are nonspecific and mimic a flu-like syndrome. Although fever represents the cardinal feature, clinical findings in malaria are extremely diverse and may range in severity from mild headache to serious complications leading to death, particularly in falciparum malaria. As the progression to these complications can be rapid, any malaria patient must be assessed and treated rapidly, and frequent observations are needed to look for early signs of systemic complications.

In fact, severe malaria is a life threatening but treatable disease. The protean and nonspecific clinical findings occurring in malaria (fever, malaise, headache, myalgias, jaundice and sometimes gastrointestinal symptoms of nausea, vomiting and diarrhoea) may lead physicians who see malaria infrequently to a wrong diagnosis, such as influenza (particularly during the seasonal epidemic flu), dengue, gastroenteritis, typhoid fever, viral hepatitis, encephalitis. Physicians should be aware that malaria is not a clinical diagnosis but must be diagnosed, or excluded, by performing microscopic examination of blood films. Prompt diagnosis and appropriate treatment are then crucial to prevent morbidity and fatal outcomes. Although Plasmodium falciparum malaria is the major cause of severe malaria and death, increasing evidence has recently emerged that Plasmodium vivax and Plasmodium knowlesi can also be severe and even fatal.

Travel-associated illness in older adults (>60 y)

BACKGROUND

Older individuals represent a substantial proportion of international travelers. Because of physiological changes and the increased probability of underlying medical conditions, older travelers might be at higher risk for at least some travel-associated diseases.

METHODS

With the aim of describing the epidemiology of travel-associated diseases in older adults, medical data were prospectively collected on ill international travelers presenting to GeoSentinel sites from 1997 to 2009. Seven thousand thirty-four patients aged 60 years and over were identified as older travelers and were compared to 56,042 patients aged 18-45 years, who were used as the young adult reference population.

RESULTS

The proportionate morbidity of several etiological diagnoses was higher in older ill travelers compared to younger ill, including notably lower respiratory tract infections, high-altitude pulmonary edema, phlebitis and pulmonary embolism, arthropod bites, severe malaria, rickettsiosis, gastritis, peptic ulcers, esophagitis and gastroesophageal reflux disease, trauma and injuries, urinary tract infections, heart disease, and death. In contrast, acute diarrhea, upper respiratory tract infections, flu and flu-like illnesses, malaria, dengue, genital infections, sexually transmitted diseases, and schistosomiasis proportionate morbidities were lower among the older group.

CONCLUSION

Older ill travelers are more likely to suffer from certain life-threatening diseases and would benefit from reinforcement of specific preventive measures including use of anti-thrombosis compression stockings and sufficient hydration and exercises during long-distance flights, hand hygiene, use of disposable handkerchiefs, consideration of face-masks in crowded conditions, influenza and pneumococcal vaccines, progressive acclimatization to altitude, consideration of acetazolamide, and use of repellents and mosquito nets. Antibiotics for the presumptive treatment of respiratory and urinary tract infections may be considered, as well as antacid medications. At-risk patients should be referred to a specialist for medical evaluation before departing, and optimal control of co-morbidities such as cardiovascular and chronic obstructive pulmonary diseases should be achieved, particularly for high-altitude travel.

Severe imported malaria in an intensive care unit: a review of 59 cases

BACKGROUND

In view of the close relationship of Portugal with African countries, particularly former Portuguese colonies, the diagnosis of malaria is not a rare thing. When a traveller returns ill from endemic areas, malaria should be the number one suspect. World Health Organization treatment guidelines recommend that adults with severe malaria should be admitted to an intensive care unit (ICU).

METHODS

Severe cases of malaria in patients admitted to an ICU were reviewed retrospectively (1990-2011) and identification of variables associated with in-ICU mortality performed. Malaria prediction score (MPS), malaria score for adults (MSA), simplified acute physiology score (SAPSII) and a score based on WHO's malaria severe criteria were applied. Statistical analysis was performed using StataV12.

RESULTS

Fifty nine patients were included in the study, all but three were adults; 47 (79,6%) were male; parasitaemia on admission, quantified in 48/59 (81.3%) patients, was equal or greater than 2% in 47 of them (97.9%); the most common complications were thrombocytopaenia in 54 (91.5%) patients, associated with disseminated intravascular coagulation (DIC) in seven (11.8%), renal failure in 31 (52.5%) patients, 18 of which (30.5%) oliguric, shock in 29 (49.1%) patients, liver dysfunction in 27 (45.7%) patients, acidaemia in 23 (38.9%) patients, cerebral dysfunction in 22 (37.2%) patients, 11 of whom with unrousable coma, pulmonary oedema/ARDS in 22 (37.2%) patients, hypoglycaemia in 18 (30.5%) patients; 29 (49.1%) patients presented five or more dysfunctions. The case fatality rate was 15.2%. Comparing the four scores, the SAPS II and the WHO score were the most sensitive to death prediction. In the univariate analysis, death was associated with the SAPS II score, cerebral malaria, acute renal and respiratory failure, DIC, spontaneous bleeding, acidosis and hypoglycaemia. Age, partial immunity to malaria, delay in malaria diagnosis and the level of parasitaemia were not associated with death in this cohort.

CONCLUSION

Severe malaria cases should be continued monitored in the ICUs. SAPS II and the WHO score are good predictors of mortality in malaria patients, but other specific scores deserve to be studied prospectively.

Risk factors for mortality from imported falciparum malaria in the United Kingdom over 20 years: an observational study

OBJECTIVES

To determine which travellers with malaria are at greatest risk of dying, highlighting factors which can be used to target health messages to travellers.

DESIGN

Observational study based on 20 years of UK national data.

SETTING

National register of malaria cases.

PARTICIPANTS

25,054 patients notified with Plasmodium falciparum malaria, of whom 184 died, between 1987 and 2006.

MAIN OUTCOME MEASURES

Comparison between those with falciparum malaria who died and non-fatal cases, including age, reason for travel, country of birth, time of year diagnosed, malaria prophylaxis used.

RESULTS

Mortality increased steadily with age, with a case fatality of 25/548 (4.6%) in people aged >65 years, adjusted odds ratio 10.68 (95% confidence interval 6.4 to 17.8), P<0.001 compared with 18-35 year olds. There were no deaths in the ≤ 5 year age group. Case fatality was 3.0% (81/2740 cases) in tourists compared with 0.32% (26/8077) in travellers visiting friends and relatives (adjusted odds ratio 8.2 (5.1 to 13.3), P<0.001). Those born in African countries with endemic malaria had a case fatality of 0.4% (36/8937) compared with 2.4% (142/5849) in others (adjusted odds ratio 4.6 (3.1 to 9.9), P<0.001). Case fatality was particularly high from the Gambia. There was an inverse correlation in mortality between region of presentation and number of cases seen in the region (R(2) = 0.72, P<0.001). Most delay in fatal cases was in seeking care.

CONCLUSIONS

Most travellers acquiring malaria are of African heritage visiting friends and relatives. In contrast the risks of dying from malaria once acquired are highest in the elderly, tourists, and those presenting in areas in which malaria is seldom seen. Doctors often do not think of these as high risk groups for malaria; for this reason they are important groups to target in pre-travel advice.

Intravenous artesunate for severe malaria in travelers, Europe

Multicenter trials in Southeast Asia have shown better survival rates among patients with severe malaria, particularly those with high parasitemia levels, treated with intravenous (IV) artesunate than among those treated with quinine. In Europe, quinine is still the primary treatment for severe malaria. We conducted a retrospective analysis for 25 travelers with severe malaria who returned from malaria-endemic regions and were treated at 7 centers in Europe. All patients survived. Treatment with IV artesunate rapidly reduced parasitemia levels. In 6 patients at 5 treatment centers, a self-limiting episode of unexplained hemolysis occurred after reduction of parasitemia levels. Five patients required a blood transfusion. Patients with posttreatment hemolysis had received higher doses of IV artesunate than patients without hemolysis. IV artesunate was an effective alternative to quinine for treatment of malaria patients in Europe. Patients should be monitored for signs of hemolysis, especially after parasitologic cure.