Malaria in paradise: characterization of imported cases in Gran Canaria Island (1993-2006)

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.

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.

[Descriptive study of malaria cases in the paediatric population in a reference hospital in Valencia, Spain, between 1993 and 2015]

INTRODUCTION

Malaria is considered to be the fourth leading cause of infant mortality after pneumonia, complications related to premature birth, and perinatal asphyxia.

MATERIAL AND METHODS

A retrospective and descriptive study of cases of malaria confirmed and treated by the Paediatric Infectious Diseases Unit (age lower than 15 years) at the La Fe Hospital, Valencia, over the period 1993 to 2015.

RESULTS

A total of 54 cases of paediatric malaria were diagnosed in the period 1993-2015, with 51.8% of these occurring in males, and 46.2% of patients were aged below 5 years. The majority of children came from Equatorial Guinea (68.5%). Only 5.6% had received antimalarial prophylaxis. Plasmodium falciparum was found to be the causal species in 81.4% of cases. Seven patients (13%) presented with complicated malaria. The most widely used treatment was quinine, either alone or in combination with other drugs. Atovaquone/proguanil was used from 2010 onwards and was indicated in 20.3% of the patients. The combination of artesunate/piperaquine/dihydroartemisinin began to be used in 2013. No deaths or relevant side effects were reported, and the clinical response was favourable in all children (100%).

CONCLUSIONS

Malaria is still a prevalent disease in this population, a consequence of immigration, and tourism to endemic countries. Malaria should be considered as a likely diagnosis in a febrile child who comes from, or has travelled to, an endemic region in the past year.

Imported malaria in a non-endemic area: the experience of the university of Campinas hospital in the Brazilian Southeast

BACKGROUND

Although malaria in Brazil almost exclusively occurs within the boundaries of the Amazon Region, some concerns are raised regarding imported malaria to non-endemic areas of the country, notably increased incidence of complications due to delayed diagnoses. However, although imported malaria in Brazil represents a major health problem, only a few studies have addressed this subject.

METHODS

A retrospective case series is presented in which 263 medical charts were analysed to investigate the clinical and epidemiological characterization of malaria cases that were diagnosed and treated at Hospital & Clinics, State University of Campinas between 1998 and 2011.

RESULTS

Amongst all medical charts analysed, 224 patients had a parasitological confirmed diagnosis of malaria. Plasmodium vivax and Plasmodium falciparum were responsible for 67% and 30% of the infections, respectively. The majority of patients were male (83%) of a productive age (median, 37 years old). Importantly, severe complications did not differ significantly between P. vivax (14 cases, 9%) and P. falciparum (7 cases, 10%) infections.

CONCLUSIONS

Severe malaria cases were frequent among imported cases in Brazil outside of the Amazon area. The findings reinforce the idea that P. vivax infections in Brazil are not benign, regardless the endemicity of the area studied. Moreover, as the hospital is located in a privileged site, it could be used for future studies of malaria relapses and primaquine resistance mechanisms. Finally, based on the volume of cases treated and the secondary complications, referral malaria services are needed in the non-endemic areas of Brazil for a rapid and efficient and treatment.

Imported malaria in Poland 2003 to 2011: implications of different travel patterns

BACKGROUND

The number of imported malaria cases in Poland compared with other European countries remains low. However, in view of the high mortality and the large proportion of severe clinical forms, a better understanding of the problem is required.

METHODS

Data reported to the surveillance system in Poland between 2003 and 2011 were reviewed retrospectively. All cases were laboratory confirmed as outlined by the EU case definition. Statistical analysis was performed using Epi Info 3.5.3 and STATA 10.

RESULTS

A total of 189 confirmed malaria cases, including 5 that were fatal, were reported in Poland during the study period. All cases were imported: 72% came from Africa. Among cases with a species-specific diagnosis, 118 (73%) were caused by Plasmodium falciparum. The median age of individuals afflicted was 36 years and 74% were males. Most cases occurred among work-related travelers (40%) or tourists (38%). Individuals born in malaria-endemic countries constituted 12% of all cases. The severe malaria form was identified in 23% of all cases and was more frequent among cases caused by P. falciparum (32%), in people older than 50 years (39%), and in cases when diagnosis was delayed (36%). The severe form occurred only in 9% of cases originating from malaria-endemic countries and there were no fatalities in this group. Fatal outcomes were associated with a delay in diagnosis (fatality = 10.5%) and falciparum malaria (fatality = 4%). Most of the delays resulted from a delay in seeking medical care, and less frequently due to misdiagnosis.

CONCLUSIONS

Tourists and work-related travelers make up most of the malaria patients in Poland and they are at a greater risk of the severe form of malaria and consequently death, possibly due to the lack of immunity. Delayed diagnosis is associated with mortality, implying low awareness of the threat that malaria poses, both among patients and doctors.

Imported malaria in Finland 2003-2011: prospective nationwide data with rechecked background information

BACKGROUND

Although described in several reports, imported malaria in Europe has not been surveyed nationwide with overall coverage of patients and individually rechecked background information. Plasmodium falciparum infections have been reported despite regularly taken appropriate chemoprophylaxis, yet the reliability of such questionnaire-based retrospective data has been questioned. This was the starting-point for conducting a prospective nationwide survey of imported malaria where compliance data was double-checked.

METHODS

Data was collected on all cases of imported malaria confirmed and recorded by the reference laboratory of Finland (population 5.4 million) from 2003 to 2011, and these were compared with those reported to the National Infectious Disease Register (NIDR). Background information was gathered by detailed questionnaires sent to the clinicians upon diagnosis; missing data were enquired by telephone of clinician or patient. Special attention was paid to compliance with chemoprophylaxis: self-reported use of anti-malarials was rechecked for all cases of P. falciparum.

RESULTS

A total of 265 malaria cases (average annual incidence rate 0.5/100,000 population) had been recorded by the reference laboratory, all of them also reported to NIDR: 54% were born in malaria-endemic countries; 86% were currently living in non-endemic regions. Malaria was mainly (81%) contracted in sub-Saharan Africa. Plasmodium falciparum proved to be the most common species (72%). Immigrants constituted the largest group of travellers (44%). Pre-travel advice was received by 20% of those born in endemic regions and 81% of those from non-endemic regions. Of those with P. falciparum, 4% reported regular use of appropriate chemoprophylaxis (mefloquine or atovaquone/proguanil or doxycycline for regions with chloroquine-resistant and atovaquone/proguanil or doxycycline for regions with mefloquine-resistant P. falciparum); after individual rechecking, however, it was found that none of them had been fully compliant.

CONCLUSIONS

Information on compliance with chemoprophylactic regimen cannot be relied on, and it should be rechecked if malaria is suspected. The results of the present study suggest that mefloquine, atovaquone/proguanil and doxycycline are effective as chemoprophylaxis against P. falciparum malaria, when taken conscientiously.

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.