Trends in imported childhood malaria in the UK: 1999-2003

Infections diagnosed in children and young people screened for malaria in UK emergency departments: a retrospective multi-centre study

BACKGROUND

Data on imported infections in children and young people (CYP) are sparse.

AIMS

To describe imported infections in CYP arriving from malaria-endemic areas and presenting to UK emergency departments (ED) who were screened for malaria.

METHODS

This is a retrospective, multi-centre, observational study nested in a diagnostic accuracy study for malaria rapid diagnostic tests. Any CYP < 16 years presenting to a participating ED with a history of fever and travel to a malaria-endemic area between 1 January 2016 and 31 December 2017 and who had a malaria screen as a part of standard care were included. Geographical risk was calculated for the most common tropical infections.

RESULTS

Of the 1414 CYP screened for malaria, 44.0% (n = 622) arrived from South Asia and 33.3% (n = 471) from sub-Saharan Africa. Half (50.0%) had infections common in both tropical and non-tropical settings such as viral upper respiratory tract infection (URTI); 21.0% of infections were coded as tropical if gastro-enteritis is included, with a total of 4.2% (60) cases of malaria. CYP diagnosed with malaria were 7.44 times more likely to have arrived from sub-Saharan Africa than from South Asia (OR 7.44, 3.78-16.41).

CONCLUSION

A fifth of CYP presenting to participating UK EDs with fever and a history of travel to a malaria-endemic area and who were screened for malaria had a tropical infection if diarrhoea is included. A third of CYP had no diagnosis. CYP arriving from sub-Saharan Africa had the greatest risk of malaria.Abbreviations: CYP: children and young people; ED: emergency department; PERUKI: Paediatric Emergency Research in the UK and Ireland; RDT: rapid diagnostic test; VFR: visiting friends and relatives.

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.

Imported Malaria in Children: A Study Over an 11-Year Period in Brussels

BACKGROUND

Malaria is a major global public health concern in endemic countries and imported childhood malaria is increasing in malaria non-endemic countries.

METHODS

This was a retrospective case review of all laboratory-confirmed malaria cases in children 0-16 years admitted between 2009 and 2019 in 2 large university teaching Hospitals in Brussels.

RESULTS

A total of 160 children with a median age of 6.8 years (range 5-191 months) were included. We identified 109 (68%) children living in Belgium who had acquired malaria during their visit to malaria-endemic countries to visiting friends and relatives (VFRs), 49 children (31%) visitors or newly installed migrants, and 2 Belgian tourists. Peak seasonal incidence occurred between August and September. Plasmodium falciparum was responsible for 89% of all malaria cases. Almost 80% of children living in Belgium visited a travel clinic for advice, but only one-third reported having taken the prophylaxis schedule according to the recommendations. Based on WHO criteria, 31 children (19.3%) developed severe malaria; most of the patients with severe malaria were VFR travelers and were significantly younger, had higher leukocytosis, had more thrombocytopenia, higher CRP, and lower natremia compared with patients with an uncomplicated course. All children recovered fully.

CONCLUSIONS

Malaria is a significant cause of morbidity among returning travelers and newly arrived immigrants to Belgium. Most of the children had an uncomplicated disease course. Physicians should educate families about traveling to malaria-endemic areas to correct malaria preventive measures and prophylaxis.

Imported arboviral infections in New Zealand, 2001 to 2017: A risk factor for local transmission

BACKGROUND/AIMS

Over the last decade and following international trends, cases of mosquito-borne arboviral infections, notably dengue fever, chikungunya and Zika, have increased among travellers arriving in New Zealand, but no locally acquired cases have been identified. Imported cases are characterised and examined to identify trends and features that might assist in reducing transmission risk from travellers.

METHODS

Information on traveller arrivals, notified cases and risk factors for disease acquisition were obtained from national sources. Trends in importation rates, seasonality are described and relationships of notifications with traveller arrivals were examined with a negative binomial regression model.

RESULTS

There was a significant increase in dengue notifications combined with the emergence of Zika and chikungunya. Most notifications were from arrivals in Auckland from Pacific Islands during summer and early autumn.

CONCLUSION/IMPLICATIONS

Overseas travel from New Zealand, particularly to the Pacific Islands and Southeast Asia, involves a risk of arboviral infection. The repeated introduction of arboviruses to New Zealand also increases the risk of local transmission in a country that has vector capable and vector potential mosquitoes, as well as an increasingly suitable climate for new vectors to establish.

Persistence of Imported Malaria Into the United Kingdom: An Epidemiological Review of Risk Factors and At-risk Groups

BACKGROUND

The United Kingdom documented a decline of >30% in imported cases of malaria annually between 1996 and 2003; however, there are still approximately 1700 cases and 5-10 deaths each year. Prophylaxis health messages focus on families returning to their country of origin.

METHODS

We reviewed 225 records of patients seen in Cambridge University Hospital Foundation Trust [CUHFT], a tertiary referral center in Cambridge, England. All records of patients seen in CUHFT between 2002-2016 were analyzed in the context of national figures from Public Health England.

RESULTS

Between 2004-2016, there was no decrease in imported cases of malaria locally or nationally. Plasmodium falciparum remains responsible for most imported infections (66.7%); Plasmodium vivax contributed 15.1%, Plasmodium malariae 4%, and Plasmodium ovale 6.7%; 7.5% (17/225) of patients had an incomplete record. Most cases were reported in people coming from West Africa. Sierra Leone and the Ivory Coast had the highest proportions of travelers being infected at 8 and 7 per 1000, respectively. Visiting family in the country of origin (27.8%) was the commonest reason for travel. However, this was exceeded by the combined numbers traveling for business and holidays (22.5% and 20.1%, respectively). Sixty percent of patients took no prophylaxis. Of those who did, none of the patients finished their chemoprophylaxis regimen.

CONCLUSIONS

Significant numbers of travelers to malarious countries still take no chemoprophylaxis. Health advice about prophylaxis before travel should be targeted not only at those visiting family in their country of origin but also to those traveling for holiday and work.

A review of wildlife tourism and meta-analysis of parasitism in Africa's national parks and game reserves

The recent increase of parasitic diseases associated with wildlife tourism can be traced to human contact with wildlife and intense modification of wildlife habitat. The continental estimates of parasitic diseases among visited wildlife-tourists and mammalian wildlife present in conservation areas are lacking; therefore, a general review was necessary to provide insights into Africa's parasitic disease burden and transmission between humans and wildlife. A two-step analysis was conducted with searches in Ovid MEDLINE, EMBASE, PubMed, Web of Science and Global Health. All diseases reported without prevalence were grouped and analysed as categorical data while meta-analysis of prevalence rates of parasitic diseases in wildlife from national parks and reserves in Africa was conducted. Only 4.7% of the tourist centres reported routine wildlife diagnosis for parasitic diseases. Disease intensity shows that cryptosporidiosis and seven other parasitic diseases were observed in both human and wildlife; however, no significant difference in intensity between human and wildlife hosts was observed. Schistosomiasis intensity reports showed a significant increase (P < 0.05) while entamoebiasis showed a significant decrease (P < 0.05) in humans as compared to wildlife. Visiting tourists were more infected with malaria, while wildlife was more infected with parasitic gastroenteritis (PGE). The meta-analysis of wildlife revealed the highest prevalence of PGE with mixed parasites and lowest prevalence of Giardia spp. at 99.9 and 5.7%, respectively. The zoonotic and socioeconomic impact of some of these parasites could pose a severe public threat to tourism. Pre- and post-travel clinical examinations are important for tourists while routine examination, treatment and rational surveillance are important for these animals to improve wildlife tourism.

Importation of travel-related infectious diseases is increasing in South Korea: An analysis of salmonellosis, shigellosis, malaria, and dengue surveillance data

BACKGROUND

International travel has an important role in transmission of emerging infectious diseases. We described the imported infectious diseases in Korea from 2003 to 2012, and to analyze association of travels with the change in the incidences.

METHODS

We used National Notifiable Disease Surveillance System to investigate the incidence of salmonellosis, shigellosis, malaria, and dengue. Data from Korea Tourism Organization was used to describe the inbound and outbound travelers by their age group, gender, and purpose of travel. We assessed association between international travel and the incidence of the infectious diseases, and seasonal variability.

RESULTS

Among 1849 imported cases, dengue comprised the largest number with 631 cases. The proportion of imported cases among total cases gradually increased from 4.1% in 2003 to 30.3% in 2012 (P < 0.001). There was a positive correlation between the number of travelers and the number of imported cases of shigellosis, dengue (P < 0.001), but not for malaria. Seasonal variability was observed for importation of salmonellosis, shigellosis and dengue fever (P = 0.005).

CONCLUSION

International travel was associated with the incidence of imported infectious diseases in Korea. Pre-travel consultation for international travelers planned to visit endemic area should be recommended strongly.

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.

Imported malaria in Scotland--an overview of surveillance, reporting and trends

BACKGROUND

Imported malaria cases continue to occur and are often underreported. This study assessed reporting of malaria cases and their characteristics in Scotland.

METHODS

Cases were identified at the study sites of Aberdeen, Edinburgh, Glasgow and Inverness. The number of cases identified in the period 2003-2008 was compared to surveillance databases from Health Protection Scotland (HPS) and the Malaria Reference Laboratory (MRL). Case characteristics were recorded and analysed.

RESULTS

Of 252 cases of malaria diagnosed and treated, an estimated 235 (93.3%) were reported to the MRL. Between 2006 and 2008, 114 of 126 cases (90.5%) were reported to HPS. Plasmodium falciparum caused 173 cases (68.7%). Business and professional travel accounted for 35.3% of cases (higher in Aberdeen), followed by visiting friends and relatives (33.1%) and holiday makers (25.5%). The majority of infections were imported from West Africa and 65.7% of patients for whom data on prophylaxis was available had taken no or inappropriate prophylaxis.

CONCLUSIONS

Reporting of malaria in Scotland can be improved. There is a continued need to optimise preventive measures and adherence to chemoprophylaxis amongst business travellers, those visiting friends and relatives, and holiday makers in endemic countries in order to reduce imported malaria cases.

Intensive care admissions for children with imported malaria in the United kingdom

This study describes 977 children with imported malaria in England and Wales between 2004 and 2008, focusing on 29 (3.0%) patients admitted to intensive care, of whom 10 had cerebral malaria, 4 required inotropes, and 1 had concurrent septicemia. The remaining 14 were admitted for monitoring only. None died, but 1 child developed cerebellar infarction.

Prospective, national clinical and epidemiologic study on imported childhood malaria in the United Kingdom and the Republic of Ireland

BACKGROUND

Current knowledge of clinical features of imported childhood malaria is largely limited to small, retrospective, and/or single-center case series. This prospective, population-based study describes the epidemiology and clinical features of imported childhood malaria in children <16 years in the United Kingdom and Republic of Ireland.

METHODS

Active prospective national surveillance with clinical data collection was performed between January 1, 2006 and January 31, 2007 through the British Pediatric Surveillance Unit and capture-recapture analysis using cases reported independently to respective national surveillance centers.

RESULTS

There were 290 cases, including 186 reported through the British Pediatric Surveillance Unit with clinical details. Capture-recapture analysis estimated the burden of imported childhood malaria to be 2.8/100,000 per year for the United Kingdom and 4.6/100,000 per year for Ireland. Black-African children born in the United Kingdom and Ireland and traveling to West Africa during school holidays without antimalarial prophylaxis accounted for the majority of cases. Thirty of 117 children (26%) who had traveled to a malaria-endemic country had previously been diagnosed with malaria, reflecting missed opportunities to educate families on malaria prevention. A third of children (46/148) with Plasmodium falciparum malaria fulfilled World Health Organization criteria for severe or potentially complicated malaria, although only 11/46 (24%) required intensive care. The choice of antimalarials varied considerably among hospitals and within the same hospital. However, recrudescence occurred in only 1 child and none died.

CONCLUSIONS

Interventions to prevent imported childhood malaria should focus on Black-African families traveling to West Africa, while pediatricians should be offered clearer guidance on the treatment of childhood malaria.

Epidemiologic features impacting the presentation of malaria in children in Houston

BACKGROUND

Malaria is diagnosed in children in the United States despite availability of effective chemoprophylaxis. The features impacting the presentation of malaria diagnosed in a nonendemic setting are not well characterized in children.

METHODS

A retrospective chart review was conducted of children with peripheral smear-confirmed malaria diagnosed from 1994 to 2007 at 4 tertiary referral hospitals in Houston, TX.

RESULTS

Among 104 children with malaria, 43 were recent immigrants and 61 were travelers leaving the United States. Severe malaria accounted for 21 (20%) of episodes. Children residing in the United States accounted for 86% of those with severe malaria. Factors relating to malaria severity included vacation-related travel (P = 0.005), female gender (P = 0.02), birth in the United States (P = 0.043), short travel duration (P = 0.024), and short duration from return to presentation (P = 0.023). Children with severe malaria more often had a history of vomiting (P = 0.048) and presented with hepatomegaly (P = 0.008), heart murmur (P = 0.041), and higher parasitemia (P < 0.001) than those with uncomplicated malaria. Vacation-related travel (aOR 7.6; 95% CI 1.4–61.5), admission hemoglobin (aOR 0.6; 95% CI 0.4–0.8), and admission platelet count (aOR 1.0; 95% CI 1.0-1.0) remained significant risk factors for severity by multivariate analysis. Prophylaxis appropriate to region of travel was documented in only 8 of 47 children leaving the United States.

CONCLUSIONS

Children diagnosed in Houston with severe malaria usually had traveled from the United States to malaria-endemic regions without benefit of appropriate prophylaxis. Malaria-related morbidity in nonendemic countries could potentially be reduced by optimizing adherence to prophylactic regimens.

Imported malaria in children: incidence and risk factors for severity

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

Protocol for management of imported pediatric malaria decreases time to medication administration

BACKGROUND

A malaria management protocol was developed and implemented at a tertiary care children's hospital in September 1999. We retrospectively evaluated children admitted with malaria 10-years preimplementation and 7-years postimplementation to determine the impact the protocol had on management and time delay to appropriate antimalarial therapy.

METHODS

This before and after study compared all admissions with the discharge diagnosis of malaria in the study period. Retrospective chart review was used to determine the time from emergency department (ED) registration to administration of antimalarial treatment. Other outcomes measured included mortality, length of hospital stay, and intensive care unit admission.

RESULTS

Fifty-eight admissions were identified during the defined period, most of which were due to Plasmodium falciparum[r] malaria. Thirty-one (53.4%) cases were before implementation of the protocol. Children were more likely to receive appropriate investigations to assess for possible severe malaria before transfer from the ED to the ward after protocol implementation (18% vs. 63%, P = 0.005). Analysis of index cases of malaria, excluding patients diagnosed after the diagnosis of a sibling, showed there was a significant reduction in time to medication administration (8 vs. 5.5 hours, P = 0.036).

CONCLUSION

After broad-based implementation of a malaria treatment protocol in a pediatric hospital, children received more thorough investigations, were more likely to receive therapy before leaving the ED and had a shorter delay before receiving appropriate antimalarial therapy.

Pediatric and adolescent imported malaria in Cape Town

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

Imported malaria among African immigrants: is there still a relationship between developed countries and their ex-colonies?

Background

The objective of this study was to compare cases of imported malaria originating from the Spanish ex-colony of Equatorial Guinea (EG) with those originating from the rest of Africa (RA).

Methods

All the African cases detected in Barcelona between 1989 and 2007 were investigated in a retrospective analysis. Clinical-epidemiological variables such as sex, age, visiting friends and relatives (VFR), species, hospital admission and chemo-prophylaxis were compared. Data were analysed by logistic regression, calculating the Odds Ratio (OR) and 95% Confidence Intervals (95% CI).

Results

Of the 489 African patients, 279 (57,1%) had been born in EG and 210 (42,9%) in the rest of Africa. The cumulative incidence of imported malaria among those from EG was 179.6 per thousand inhabitants, while in those from the RA it was 33.7 per thousand (p < 0.001). Compliance with chemoprophylaxis (CP) was very low, but there were no differences between the two groups. Comparing those from EG to those from RA, the former were characterized by having more patients in the visiting friends and relatives (VFR) category, and more individuals younger than 15 years or older than 37 years, and more women. They also visited a traveller's health centre more often, had fewer hospital admissions and were less likely to reside in the inner city.

Conclusion

Cases of imported malaria originating in Africa, are more likely to come from the Spanish ex-colony of EG, and VFR are more likely to be affected. It is recommended that developed countries promote prevention programmes, such as CP advice directed at African immigrants, and develop programmes of cooperation against malaria in their ex-colonies.

Import of malaria in a Romanian Western County

BACKGROUND

Malaria is not a serious concern in Romania nowadays although 30-60 imported cases are diagnosed yearly, especially in travellers from Africa. Timis, the most extensive of the Romanian counties, is the western gate of the country from where a lot of people travel abroad. The aim of this study is to overview all the imported cases of malaria diagnosed in our county and to describe two recent severe cases.

METHODS

We retrospectively analyzed both the medical records of 28 malaria patients treated between 1974 and 2007 at Victor Babes Hospital of Infectious Disease from Timisoara, Romania, and the results of 6 blood examinations performed in the last decade in the parasitological laboratory of Victor Babes University of Medicine and Pharmacy from Timisoara. A comparison between the two recent severe cases was made, emphasizing on the clinical aspects, complications and the laboratory test results.

RESULTS

Most of the patients (55.38%) were in the age group of 20-29 years; 85.71% of the patients were males; Plasmodium falciparum was found in 75% of the cases.

CONCLUSIONS

Findings of our study have shown that P. falciparum is the main malaria species in Timis County, outlining the difficulties in the diagnosis and management of the imported cases.

Imported malaria in children: a review of clinical studies

Imported malaria is a preventable disease, yet it is responsible for several thousand cases and a substantial number of deaths every year. There has been a pronounced rise in the incidence of imported malaria in most developed countries over the past three decades and, more concerning, Plasmodium falciparum, which is responsible for almost all cases of severe malaria, is now the most prevalent species. Children account for around 15-20% of all imported malaria cases and must be considered separately from adults because they have different risk factors for developing malaria and a higher risk of developing severe disease since they are more likely to be non-immune to malaria. We did a thorough review of the literature since 1980 to identify and critically assess clinical case series on children with imported malaria with respect to travel destination, reason for travel, the use of antimalarial prophylaxis, clinical presentation, delay in diagnosis, laboratory features, complications, management, and outcome. Children living in non-endemic countries and travelling during school holidays to visit family and relatives in their parents' country of origin currently account for the largest proportion of cases in many European countries. This group of travellers deserves special attention because they often do not take antimalarial prophylaxis or other preventive measures. There is a need for standardised recommendations on management and prevention of imported malaria in children, which should be supported by large multicentre clinical trials. A prospective national surveillance study on imported malaria in children was launched in the UK and Ireland through the British Paediatric Surveillance Unit in 2006, which may provide answers to some of the questions raised in this Review.