Epidemiology of imported malaria among children and young adults in Barcelona (1990-2008)

Imported malaria in children in Alicante, Spain (1994-2019)

Introduction: In recent years there has been an increase in imported malaria among children in whom it is a potentially serious and fatal disease. Objective: To describe the incidence and the clinical and epidemiological characteristics of malaria in children diagnosed in Alicante, Spain, over a 26-year period. Materials and methods: We conducted an observational retrospective study of malaria in children aged under 15 years diagnosed at the Alicante General University Hospital from 1994 to 2019. Results: Twenty-four cases were registered over the study period. The frequency of cases increased from 2 over the first five years to 11 in the last five years. The median age of the children was 6 years (interquartile range: 3-8); 91.6% came from sub-Saharan Africa. Over half (n=15, 62.5%) were children born in Spain to immigrant parents visiting friends and relatives (VFR); just one (6.7%) had received antimalarial chemoprophylaxis. The most frequent clinical signs were fever (86.9%), hepatosplenomegaly (70.8%), and anemia (70.8%). Plasmodium falciparum was the most frequently identified species (83.3%, n=20). The most common treatment was oral piperaquine/dihydroartemisinin (41.6%, n=10) with favorable outcomes in all cases. Conclusions: Imported childhood malaria shows an increasing incidence and a nonspecific clinical presentation. Professional awareness of this disease and a high degree of clinical suspicion are needed for the early initiation of treatment. Pre-travel preventive measures should be promoted when appropriate.

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.

Spatiotemporal Distribution of Malaria in Spain in a Global Change Context

Malaria is one of the most cited vector-borne infectious diseases by climate change expert panels. Malaria vectors often need water sheets or wetlands to complete the disease life cycle. The current context of population mobility and global change requires detailed monitoring and surveillance of malaria in all countries. This study analysed the spatiotemporal distribution of death and illness cases caused by autochthonous and imported malaria in Spain during the 20th and 21st centuries using multidisciplinary sources, Geographic Information System (GIS) and geovisualisation. The results obtained reveal that, in the 20th and 21st centuries, malaria has not had a homogeneous spatial distribution. Between 1916 and 1930, 77% of deaths from autochthonous malaria were concentrated in only 20% of Spanish provinces; in 1932, 88% of patients treated in anti-malarial dispensaries were concentrated in these same provinces. These last data reveal the huge potential that anti-malarial dispensaries could have as a tool to reconstruct historical epidemiology. Spanish autochthonous malaria has presented epidemic upsurge episodes, especially those of 1917–1922 and 1939–1944, influenced by armed conflict, population movement and damaged health and hygiene conditions. Although meteorological variables have not played a key role in these epidemic episodes, they contributed by providing suitable conditions for their intensification. After the eradication of autochthonous malaria in 1961, imported malaria cases began to be detected in 1973, reaching more than 700 cases per year at the end of the second decade of the 21st century. Therefore, consistent and detailed historical studies are necessary to better understand the drivers that have led to the decline and elimination of malaria in Europe and other temperate countries.

Imported malaria cases: the connection with the European ex-colonies

Background

Imported malaria is increasing in non-endemic areas due to the increment of international travels, migration and, probably, other unknown factors. The objective of this study was to describe the epidemiological and clinical characteristics of malaria cases in a region of Spain; analyse the possible association between the variables of interest; compare this series with others; and evaluate the characteristics of imported malaria cases according to the country of origin, particularly cases from Equatorial Guinea (Spanish ex-colony) and from the rest of sub-Saharan Africa.

Methods

A descriptive observational study was carried out with a retrospective data collection of cases of malaria reported in Aragon from 1996 to 2017. Univariate and bivariate analysis of clinical–epidemiological variables was performed. In addition, an analysis of cases from sub-Saharan Africa was carried out using logistic regression, calculating odds ratio with its 95% confidence interval.

Results

609 cases of malaria were recorded in Aragon from 1996 to 2017. An autochthonous case in 2010. 50.33% were between 15 and 39 years old. 45.65% of the cases were notified of the 4-weeks 9 to 12. 82.6% reside in the main province, urban area, of which 65.4% were VFR (Visiting Friends and Relatives), 23.8% new immigrants and 10.9% travellers. The infectious Plasmodium species par excellence was Plasmodium falciparum (88%). Analysing the cases from sub-Saharan Africa (95.2% of the total), 48.1% were from Equatorial Guinea. Comparing these with the cases from the rest of sub-Saharan Africa, it was observed that the cases from the Spanish ex-colony have association with the female gender, being under 5 years old, residing in the main province (urban area) and being a new immigrant.

Conclusions

The epidemiological profile of imported malaria cases can be defined as VFR between 15 and 39 years old, coming from sub-Saharan Africa, particularly from Equatorial Guinea. Immigrants education about the importance of chemoprophylaxis when travelling to visit friends and relatives, emphasizing on those who are originally from the ex-colonies of destination country, is necessary; as well as to raise awareness among health professionals to make advice in consultations, specially before summer vacations.

Imported malaria including HIV and pregnant woman risk groups: overview of the case of a Spanish city 2004-2014

BACKGROUND

Arrival of inmigrants from malaria endemic areas has led to a emergence of cases of this parasitic disease in Spain. The objective of this study was to analyse the high incidence rate of imported malaria in Fuenlabrada, a city in the south of Madrid, together with the frequent the lack of chemoprophylaxis, for the period between 2004 and 2014. Both pregnant women and HIV risk groups have been considered.

METHODS

Retrospective descriptive study of laboratory-confirmed malaria at the Fuenlabrada University Hospital, in Madrid, during a 10-year period (2004-2014). These data were obtained reviewing medical histories of the cases. Relevant epidemiological, clinical and laboratory results were analysed, with focus on the following risk groups: pregnant women and individuals with HIV.

RESULTS

A total of 185 cases were diagnosed (90.3 % Plasmodium falciparum). The annual incidence rate was 11.9/100,000 inhabitants/year. The average age was 30.8 years (SD: 14.3). Infections originating in sub-Saharan Africa comprised the 97.6 % of the cases. A total of 85.9 % were Visiting Friends and Relatives. Only a 4.3 % completed adequate prophylaxis. A total of 14.28 % of the fertile women were pregnant, and 8 cases (4.3 %) had HIV. None of them in these special groups completed prophylaxis.

CONCLUSIONS

The incidence rate in Fuenlabrada is higher than in the rest of Spain, due to the large number of immigrants from endemic areas living in the municipality. However, the results are not representative of all the country. It seems to be reasonable to implement prevention and pre-travel assessment programs to increase chemoprophylaxis. Pregnancy tests and HIV serology should be completed for all patients to improve prophylactic methods.

A retrospective study on imported malaria in Jordan. 2. Malaria among non-military Jordanians

Cases of imported malaria among civilian Jordanians returning from Asian and African countries from 1991-2011 are documented. A total of 511 cases of imported malaria were diagnosed among civilian Jordanians travelling abroad. Majority of cases were reported among adults over 21 year old accounting for or 87,67% of the total number of cases. Eighteen different categories of occupation were identified, where as students studying abroad showed the highest infection rate (33.2%), especially those returning from India (n=70). Infection among males was as high as 91.78%, compared to 8.22% in females. Females were mostly housewives accompanying their spouses. Cases were reported from 34 Asian and African countries.Most cases were reported among Jordanians returning from Pakistan (23.68%), Yemen (18.6%), India (18.4%) and Sudan (5.1%). The majority of infections were due to Plasmodium vivax (n=370, 72.4%), followed by Plasmodium falciparum (n=138, 27%). Only one case of Plasmodium malariae was observed. Few cases (n=3, 0.65%) of mixed infection with P. vivax and P. falciparum were reported. Sudan was the main source of P. falciparum (25.4%) followed by Yemen (20.3%), while Pakistan was the main source of P. vivax (28.9%) followed by India (22.7%). Most mixed infection cases were acquired in Sudan (66.7%).

Risk factors for UK Plasmodium falciparum cases

BACKGROUND

An increasing proportion of malaria cases diagnosed in UK residents with a history of travel to malaria endemic areas are due to Plasmodium falciparum.

METHODS

In order to identify travellers at most risk of acquiring malaria a proportional hazards model was used to estimate the risk of acquiring malaria stratified by purpose of travel and age whilst adjusting for entomological inoculation rate (EIR) and duration of stay in endemic countries.

RESULTS

Travellers visiting friends and relatives and business travellers were found to have significantly higher hazard of acquiring malaria (adjusted hazard ratio (HR) relative to that of holiday makers 7.4, 95% CI 6.4-8.5, p < 0. 0001 and HR 3.4, 95% CI 2.9-3.8, p < 0. 0001, respectively). All age-groups were at lower risk than children aged 0-15 years.

CONCLUSIONS

These estimates of the increased risk for business travellers and those visiting friends and relatives should be used to inform programmes to improve awareness of the risks of malaria when travelling.

Epidemiology of imported malaria in the mediterranean region

Malaria is one of the most widespread infectious diseases of our time, causing 655 000 deaths during 2010 (WHO), most of them in sub-Saharan Africa and under the age of 5. During the last few years an increasing number of imported malaria cases is reported in Europe and Mediterranean countries, probably supported by the increasing number of international travel in association with the important influx of immigrants from malaria-endemic countries. Moreover, the presence of Anopheline vectors in Mediterranean countries, the returned infected travellers as a source of parasite and climate changes may result in the reappearance of malaria in countries where it was previously eradicated, such as Greece in recent years. Several cases of autochthonous malaria have recently been reported to support the need of an ongoing surveillance for mosquito control and an increased vigilance by health professionals. The aim of this paper is to critically review all the available literature about imported malaria in Mediterranean areas and the potential consequences of this.

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.