Pediatric imported malaria in New York: delayed diagnosis

Risk of malaria associated with travel to malaria-endemic areas to visit friends and relatives: a population-based case-control study

BACKGROUND

Reports relying on population-based data and using epidemiologic methodologies such as case-control study designs for malaria in travellers and multivariable regression analysis of risk factors are rare. The aim of this study was to investigate the epidemiologic characteristics of travellers who tested positive for malaria after visiting friends and relatives in malaria-endemic areas to determine the risk of malaria associated with such travel.

METHODS

Using routinely collected data from a population-based laboratory database, we conducted a case-control study of symptomatic people returning from travel to malaria-endemic areas who presented for malaria testing in Calgary from 2013 to 2017. We used a multivariable logistic regression to analyze the association between the presence of malaria and other risk factors.

RESULTS

There were 251 confirmed malaria cases during the study period, of which 219 were matched to 1129 returning travellers without malaria. Based on the multivariable regression, the odds of a traveller who visited friends and relatives in malariaendemic areas being diagnosed with malaria was 2.82 (95% confidence interval [CI] 1.42-5.92) times greater than that of other travellers to these regions. Adults (odds ratio [OR] 3.62, 95% CI 1.66-8.84), males (OR 2.70, 95% CI 1.56-4.80), travellers to Africa (OR 11.52, 95% CI 6.33-22.05) and those who did not seek pretravel advice (OR 0.38, 95% CI 0.20-0.70) were more likely to be diagnosed with malaria. Although those travelling to visit friends and relatives tended to stay longer in endemic areas than other travellers, visit duration was not associated with an increased likelihood of malaria in the model. The annual incidence of malaria was highest (13.34 per 100 000) in metropolitan wards associated with lower socioeconomic status and immigrant communities.

INTERPRETATION

Travellers who visited friends and relatives in malaria-endemic areas were less likely than other travellers to these regions to seek pretravel advice, take prophylaxis and have a visit duration less than 2 weeks; travelling to Africa and being male increased the odds of being diagnosed with malaria, independent of other factors. These data suggest that targeted strategies to provide pretravel care to travellers who visit friends and relatives in malaria-endemic areas may aid in reducing the burden of malaria in this population.

Higher Rates of Misdiagnosis in Pediatric Patients Versus Adults Hospitalized With Imported Malaria

OBJECTIVES

Despite the availability of effective antimalarial prophylaxis, imported adult and pediatric malaria occurs in the United States, and this can pose diagnostic issues. We examined the clinical characteristics and diagnostic challenges of imported malaria requiring adult or pediatric inpatient admission at Montefiore Medical Center in the Bronx which provides care for a large population of immigrants from malaria endemic areas.

STUDY DESIGN

We conducted a retrospective single center review of patients admitted with a diagnosis of malaria at Montefiore Medical Center from 2005 through 2012. We extracted historical, clinical, and laboratory values from the electronic medical record and patient charts.

RESULTS

We identified 95 patients who were diagnosed and hospitalized with malaria from 2005 to 2012, 33 (35%) of them were children and 17 (18%) were with severe malaria. Most patients contracted malaria while visiting friends and relatives in West Africa. Only 38% of travelers took prophylaxis, and fewer than half reported taking it as prescribed. Misdiagnosis by emergency room or primary care doctors was observed in almost one quarter of all of the patients. Misdiagnosis occurred significantly more frequently in children (43%) compared to adults (13%) (P = 0.002). Pediatric patients were more likely to present with abdominal pain (42% vs. 15%; P = 0.005).

CONCLUSIONS

Pediatric patients admitted for imported malaria at Montefiore Medical Center had a higher rate of misdiagnosis and presented with more gastrointestinal symptoms than hospitalized adults. By describing the clinical characteristics of patients with imported malaria, we hope to improve diagnostic accuracy by health care workers and raise awareness that friends and relatives may require more intensive pretravel counseling.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Imported pediatric malaria at the Hospital for Sick Children, Toronto, Canada: a 16 year review

Background

Children under 5 represent 86% of annual malaria deaths in the world. Following increasing trends in international travel, cases of imported malaria are rising in North America. We describe the epidemiology of malaria diagnosed at a tertiary care pediatric center in the multicultural city of Toronto.

Method

Retrospective chart review of all laboratory confirmed malaria from birth to <18 years between July 1, 1997 and June 30, 2013. Epidemiological data, travel history, chemoprophylaxis history, as well as clinical presentation, diagnosis and treatment were extracted.

Results

In total 107 children were diagnosed with malaria in the 16 year time period. Plasmodium falciparum malaria was identified in 76 (71%), Plasmodium vivax in 28 (26%). Median age of infected children was 6.7 years where 35% of children were born in Canada, 63% were recent or previous immigrants. Of those who resided in Canada, reason for travel included visiting friends or relatives (VFR) 95% and tourism or education (5%). Most common countries of infection were Ghana (22%), Nigeria (20%) and India (14%). Median parasitemia at presentation to our institution was 0.4% (IQR 0.1-2.3) with a maximum parasitemia of 31%. Nineteen (18%) met the WHO criteria for severe malaria due to hyperparasitemia, with 3 of these cases also meeting clinical criteria for severe malaria. One third of patients had a delay in treatment of 2 or more days. Ten percent of children had seen two or more primary health care professionals prior to admission. Prophylaxis was documented in 22 (21%), and out of those, 6 (27%) were appropriate for the region of travel and only 1 case was documented as adherent to their prescription. There were no cases of fatality.

Conclusion

Malaria continues to be a significant disease in returning travelers and immigrant or refugee populations. An increase in physician awareness is required. Appropriate pre-travel advice, insect protection measures, effective chemoprophylaxis is needed to reduce the incidence and improve the management of imported pediatric malaria.

Paediatric malaria in Greece in the era of global population mobility

We reviewed the medical records of children admitted because of malaria to four tertiary-care hospitals in Greece during 1972-2002. A total of 21 cases were found, including 20 (95.2%) diagnosed during 2003-2012. Sixteen (76.2%) children had been in a malaria-endemic country within a median of 50 days before the onset of their symptoms. Main causes of travel were immigration to Greece and to visit friends and relatives (VFRs). A considerable epidemiological shift of paediatric malaria occurred in Greece during the past decade, which is attributed almost exclusively to the increase of immigrants and travellers VFRs.

Imported pediatric malaria presenting to an urban pediatric emergency department: a case series

OBJECTIVE

The objective of this study was to identify common presenting signs, symptoms, and laboratory findings of imported pediatric malaria presenting to a US pediatric emergency department (ED).

METHODS

This is a retrospective chart review of all patients presenting to an urban pediatric ED between July 1, 2004, and July 1, 2011, who were assigned an ED or inpatient discharge diagnosis of "malaria" and had a confirmed blood smear demonstrating plasmodium species.

RESULTS

There were 21 patients included in this study (median age, 12 years; range, 19 months to 22 years). A total of 15 (71%) were infected with Plasmodium falciparum subtype of malaria. Patients presented to the ED between 1 day and 2 years after return from a malaria-endemic area. All 21 patients (100%) reported a history of fever, but only 9 (43%) had a fever documented in the ED. Of the patients, 14 (66%) complained of headache, 13 (62%) complained of anorexia, 11 (52%) complained of chills, and 10 (48%) complained of abdominal pain. The most common sign was tachycardia, present in 18 patients (86%). Consistent with other studies, thrombocytopenia was the most frequently observed laboratory abnormality, present in 16 patients (76%).

CONCLUSIONS

The presenting signs and symptoms of imported pediatric malaria are nonspecific and inconsistently present, underscoring the importance of maintaining a high index of suspicion for this diagnosis in any patient returning from a malaria-endemic region.

Rolling back malaria: how well is Europe doing?

Background. The Roll Back Malaria (RBM) initiative has committed itself to halving the worlds's malaria burden by 2010, having adopted five operationally focused 'critical concepts' to guide this task. The focus of RBM's efforts is in the developing world where external support is often required. Malaria was only recently eradicated from Europe, and the continent remains under continual threat of reintroduction. The extent of this threat is examined, and the European response benchmarked against RBM's critical concepts. Methods. The following sources were searched for references using the phrase "imported malaria": RBM, WHO, European Union including Eurosurveillance, and MedLine websites. Links to related articles were followed. Citations were independently assessed by the authors for relevance and inclusion. Results. Only in application of the critical concept "disease surveillance" does the European response seem adequate. Conclusions. Europe should be making greater efforts and considering additional strategies to combat imported malaria.

Pediatric travelers visiting friends and relatives (VFR) abroad: illnesses, barriers and pre-travel recommendations

Global mobility has shown a steady rise in recent years, with increased immigration and international travel. The VFR traveler is a traveler whose primary purpose of travel is to visit friends and relatives (VFR), where there is a gradient of risk between home and destination. Children are more likely to be VFR travelers than adults. Pediatric VFR travelers have higher risks for certain infectious travel-related illnesses and face multiple barriers in receiving comprehensive pre-travel care. This review focuses on the current state of knowledge of the pediatric VFR traveler, including epidemiological risks, barriers to adequate pre-travel services, and specific recommendations for disease prevention.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Imported malaria in children: a comparative study between recent immigrants and immigrant travelers (VFRs)

BACKGROUND

In Europe, imported malarial cases occur in returning travelers and immigrants mostly from African countries. There have been an increasing number of cases in the past years in Spain.

METHODS

An analysis of all cases of malaria who attended at the Hospital of Mostoles in the Southwest of Madrid from 1995 to 2007 was performed. Clinical, epidemiological, laboratory, and parasitological findings were analyzed and compared between immigrants coming from endemic countries (recent immigrants) and children who traveled to endemic areas to visit friends and relatives (VFRs).

RESULTS

Sixty cases of imported malaria were detected. Most of the cases (59 of 60) were acquired in sub-Saharan Africa. The most common species was Plasmodium falciparum (43 of 60). Microscopic examination was positive in 95%, and the polymerase chain reaction (PCR) for Plasmodium achieved additional diagnosis in seven cases. Fourteen cases were VFRs; none of them used appropriate malaria chemoprophylaxis. Fever and thrombocytopenia were significantly more common among VFRs. They also had significantly higher parasite density. Twelve cases were asymptomatic at the time of diagnosis; all of them were recent immigrants.

CONCLUSIONS

VFRs account for a significant number of childhood malarial cases. These patients had not taken malaria chemoprophylaxis and malarial cases were more severe. VFR children are a high-risk group, and pretravel advice should underline the risk for malaria. Recent immigrants can be asymptomatic and parasitemias are lower. Therefore, a high index of suspicion is necessary, and PCR for Plasmodium should be performed in case of negative thick smears.

Hyponatraemia in imported malaria is common and associated with disease severity

BACKGROUND

Hyponatraemia (serum sodium < 135 mmol/L) has long been recognized as a complication of malaria. However, few studies have been done in non-immune adult populations. It has not been investigated previously how hyponatraemia is distributed among the various Plasmodium species, and its association with malaria severity is unknown.The aim of this retrospective cohort study was to determine the prevalence of hyponatraemia and its association with malaria severity in a large cohort of patients with imported malaria caused by various Plasmodium species.

METHODS

All patients that were diagnosed with malaria in the Harbour Hospital and Institute for Tropical Diseases in Rotterdam in the period 1999-2009 and who had available serum sodium on admission were included. Severe malaria was defined according to the modified WHO criteria. Prevalence of hyponatraemia and its association with malaria severity were investigated by univariate comparison, ROC analysis and multivariate logistic regression analysis.

RESULTS

A total of 446 patients with malaria (severe falciparum malaria n = 35, non-severe falciparum malaria n = 280, non-falciparum malaria n = 131) was included. Hyponatraemia was present in 207 patients (46%). Prevalence and severity of hyponatraemia were greatest in severe falciparum malaria (77%, median serum sodium 129 mmol/L), followed by non-severe falciparum malaria (48%, median serum sodium 131 mmol/L), and non-falciparum malaria (34%, median serum sodium 132 mmol/L). Admission serum sodium < 133 mmol/L had a sensitivity of 0.69 and a specificity of 0.76 for predicting severe malaria. Multivariate logistic regression showed that serum sodium < 131 mmol/L was independently associated with severe falciparum malaria (odds ratio 10.4, 95% confidence interval 3.1-34.9). In patients with hyponatraemia, hypovolaemia did not appear to play a significant role in the development of hyponatraemia when prerenal azotaemia and haematocrit were considered as surrogate markers for hypovolaemia.

CONCLUSIONS

Hyponatraemia is common in imported malaria and is associated with severe falciparum malaria. From a clinical point of view, the predictive power of hyponatraemia for severe malaria is limited. The precise pathophysiological mechanisms of hyponatraemia in malaria require further study.

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.

Avian influenza--a review for doctors in travel medicine

First identified in humans in Hong Kong, influenza A/H5N1, known commonly as avian influenza, has caused human disease in 15 countries around the world. Although the current number of confirmed patients is tiny compared to seasonal and the recently emerged H1N1 'swine' influenza, H5N1 remains a candidate for the next highly pathogenic influenza pandemic. Currently, H5N1 has very limited ability to spread from person-to-person but this may change because of mutation or reassortment with other influenza viruses leading to an influenza pandemic with high mortality. If this occurs travellers are likely to be affected and travel medicine doctors will need to consider avian influenza in returning febrile travellers. The early clinical features may be dismissed easily as 'the flu' resulting in delayed treatment. Treatment options are limited. Oral oseltamivir alone has been the most commonly used drug but mortality remains substantial, up to 80% in Indonesia. Intravenous peramivir has been filed for registration and IV zanamivir is being developed. This review will focus on the epidemiological and clinical features of influenza A/H5N1 avian influenza and will highlight aspects relevant to travel medicine doctors.

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 in children in industrialized countries, 1992-2002

Children account for a considerable proportion of cases imported to the United States and Europe.

Children account for an appreciable proportion of total imported malaria cases, yet few studies have quantified these cases, identified trends, or suggested evidence-based prevention strategies for this group of travelers. We therefore sought to identify numbers of cases and deaths, Plasmodium species, place of malaria acquisition, preventive measures used, and national origin of malaria in children. We analyzed retrospective data from Australia, Denmark, France, Germany, Italy, Japan, the Netherlands, Sweden, Switzerland, the United Kingdom, and the United States and data provided by the United Nations World Tourism Organization. During 1992–2002, >17,000 cases of imported malaria in children were reported in 11 countries where malaria is not endemic; most (>70%) had been acquired in Africa. Returning to country of origin to visit friends and relatives was a risk factor. Malaria prevention for children should be a responsibility of healthcare providers and should be subsidized for low-income travelers to high-risk areas.

Congenital malaria: the least known consequence of malaria in pregnancy

Congenital malaria is the least known manifestation of malaria and a very neglected area of research. Most of the existing information is limited to case reports in children born to non-immune women. With the use of molecular techniques, congenital infection is being increasingly detected among infants born to semi-immune women in endemic countries. However, many gaps in knowledge remain. The mechanisms and timing of infection are unclear. Furthermore, there is a lack of information on the impact of congenital malaria infection on the subsequent risk of malaria and general morbidity in the infant. There is also a lack of consensus on the clinical guidelines for its management. More research is needed in order to establish adequate preventive and management recommendations to avoid this consequence of malaria in pregnancy.

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.

The basic principles of migration health: population mobility and gaps in disease prevalence

Currently, migrants and other mobile individuals, such as migrant workers and asylum seekers, are an expanding global population of growing social, demographic and political importance. Disparities often exist between a migrant population's place of origin and its destination, particularly with relation to health determinants. The effects of those disparities can be observed at both individual and population levels. Migration across health and disease disparities influences the epidemiology of certain diseases globally and in nations receiving migrants. While specific disease-based outcomes may vary between migrant group and location, general epidemiological principles may be applied to any situation where numbers of individuals move between differences in disease prevalence. Traditionally, migration health activities have been designed for national application and lack an integrated international perspective. Present and future health challenges related to migration may be more effectively addressed through collaborative global undertakings. This paper reviews the epidemiological relationships resulting from health disparities bridged by migration and describes the growing role of migration and population mobility in global disease epidemiology. The implications for national and international health policy and program planning are presented.

Delay in diagnosis of imported Plasmodium falciparum malaria in children

The study reported here prospectively evaluated the time-to-diagnosis of imported Plasmodium falciparum malaria in children in seven French pediatric emergency departments during a 1-week period. For the 29 patients included, the mean patient, doctor and total delays were 3.1, 1.5 and 4.7 days, respectively. The late medical diagnosis for 11 patients was mainly due to the treating physician's failure to consider malaria, despite having been informed that the child had been in an endemic area, and erroneously making a diagnosis of viral infection. The five patients who were diagnosed correctly without delay had higher mean platelet counts than the others (206,000 vs 118,541/mm(3); p=0.008). The results indicate that greater awareness of the risk of malaria in returning travelers may help reduce delays in diagnosis and its consequences.

Malaria "epidemic" in Quebec: diagnosis and response to imported malaria

BACKGROUND

Imported malaria is an increasing problem. The arrival of 224 African refugees presented the opportunity to investigate the diagnosis and management of imported malaria within the Quebec health care system.

METHODS

The refugees were visited at home 3-4 months after arrival in Quebec. For 221, a questionnaire was completed and permission obtained for access to health records; a blood sample for malaria testing was obtained from 210.

RESULTS

Most of the 221 refugees (161 [73%]) had had at least 1 episode of malaria while in the refugee camps. Since arrival in Canada, 87 (39%) had had symptoms compatible with malaria for which medical care was sought. Complete or partial records were obtained for 66 of these refugees and for 2 asymptomatic adults whose children were found to have malaria: malaria had been appropriately investigated in 55 (81%); no malaria smear was requested for the other 13. Smears were reported as positive for 20 but confirmed for only 15 of the 55; appropriate therapy was verified for 10 of the 15. Of the 5 patients with a false-positive diagnosis of malaria, at least 3 received unnecessary therapy. Polymerase chain reaction testing of the blood sample obtained at the home visit revealed malaria parasites in 48 of the 210 refugees (23%; 95% confidence interval [CI] 17%- 29%). The rate of parasite detection was more than twice as high among the 19 refugees whose smears were reported as negative but not sent for confirmation (47%; 95% CI 25%- 71%).

INTERPRETATION

This study has demonstrated errors of both omission and commission in the response to refugees presenting with possible malaria. Smears were not consistently requested for patients whose presenting complaints were not "typical" of malaria, and a large proportion of smears read locally as "negative" were not sent for confirmation. Further effort is required to ensure optimal malaria diagnosis and care in such high-risk populations.

Pediatric malaria in the developing world

Hundreds of millions of people suffer from malaria, and more than a million children die of malaria each year. Malaria typically presents with fever and headache, but the presentation often is nonspecific. The diagnosis should be based on blood tests, and thick and thin smears are the standard means of identifying parasites. In some areas, chloroquine still is effective as treatment, but other medications are needed in most parts of the world. Patients with severe disease (altered consciousness, marked anemia, and/or respiratory distress) should begin therapy parenterally. Control measures depend on the use of insecticide-treated bednets, early identification and treatment of symptomatic individuals, and intermittent preventive therapy. Progress continues toward the development of a useful vaccine.

Prevention of infectious diseases among international pediatric travelers: considerations for clinicians

An estimated 1.9 million children travel overseas annually. Infectious disease risks associated with international travel are diverse and depend on the destination, planned activities, and baseline medical history. Children have special needs and vulnerabilities that should be addressed when preparing for travel abroad. Children should have a pretravel health assessment that includes recommendations for both routine and special travel-related vaccination; malaria chemoprophylaxis, if indicated; and prevention counseling regarding insect and animal exposures, food and water safety, and avoiding injuries. Special consideration should be given to children with chronic diseases. Families should be given anticipatory guidance for management of potential illnesses and information about the location of medical resources overseas.

Diagnosis and Treatment of Malaria in Children

Malaria continues to be a problem for children returning or immigrating to industrialized countries from tropical regions. Proper diagnosis begins with clinical suspicion. In nonimmune children, malaria typically presents with high fever that might be accompanied by chills and headache. Symptoms and signs may be more subtle in partially immune children, and anemia and hepatosplenomegaly may also be present. Children may present with respiratory distress and/or rapidly progressing cerebral malaria that manifests as altered sensorium and, sometimes, seizures. Thick blood smears help to determine when infection is present, but a single smear without parasites is not sufficient to rule out malaria. Thin blood smears aid in identifying the species of parasite. Treatment must include careful supportive care, and intensive care measures should be available for treating children with complicated Plasmodium falciparum malaria. Medical regimens can include mefloquine, atovaquone-proguanil, sulfadoxine-pyrimethamine, quinine or quinidine, clindamycin, doxycycline, chloroquine, and primaquine.

Childhood malaria in East London

OBJECTIVES

To describe the epidemiologic, clinical and laboratory features of children younger than 16 years with malaria in East London.

METHODS

Retrospective case review of all children admitted to two East London hospitals with malaria identified between 1996 and 2001 with the use of notifications and hospital discharge data.

RESULTS

A total of 211 children with a median age of 9 years (range, 11 to 179 months) were identified. Children living in the UK who acquired malaria while visiting a malaria-endemic country on holiday accounted for 82% of cases, whereas the rest were children visiting the UK from endemic areas. Three-fourths of children who had traveled to a malaria-endemic area were born in the UK, and 93% were of Black African ethnicity. The peak seasonal incidence was late summer/early autumn. Plasmodium falciparum acquired in Africa accounted for 91% of cases. Although 42% of children took antimalarial prophylaxis, only 15% of medications were taken according to recommended guidelines. Another family member, most often a sibling, was found to have concurrent malaria in 23% (49 of 211) of cases. On the basis of the WHO criteria, 15 children (7.1%) 15 months to 15 years of age had severe malaria, including convulsions (n = 4), acute renal failure (n = 3), jaundice (n = 4), severe anemia (n = 3) and >2% parasitemia (n = 6).

CONCLUSIONS

The majority of children with malaria in this study were UK-born, school age, of Black African ethnicity and were visiting family in Africa, often with other family members. Most children had low level parasitemia and uncomplicated malaria, and they responded rapidly to antimalarial treatment.

Increasing Plasmodium falciparum malaria in southwest London: a 25 year observational study

AIMS

To identify changes in the presenting number and species of imported malaria in children in southwest London.

METHODS

A prospective single observer study over 25 years (1975-99) of all cases of paediatric malaria seen at St George's Hospital.

RESULTS

A confirmed diagnosis was made in 249 children (56% boys; 44% girls; median age 8.0 years). Of these, 53% were UK residents and 44% were children travelling to the UK. A significant increase was noted in the number of cases over the 25 years (1975-79: mean 4.8 cases/year; 1990-99: mean 13.7 cases/year). Over the 25 years Plasmodium falciparum was seen in 77%, P vivax in 14%, P ovale in 6%, and P malariae in 3% of cases. P falciparum had increased in frequency (1975-79: P falciparum 50%, P vivax 50%; 1990-99: P falciparum 82%, P vivax 6%), associated with an increase in the proportion of children acquiring their infection in sub-Saharan Africa. Median time between arrival in the UK to the onset of fever was: P falciparum, 5 days; P ovale, 25 days; P malariae, 37 days; and P vivax, 62 days. Median time interval between the onset of fever to commencement of treatment was 4 days. This had not improved over the 25 year period. Only 41% of UK resident children presenting to hospital had taken prophylaxis and the overall number of symptomatic children taking no prophylaxis was increasing.

CONCLUSION

Imported childhood P falciparum malaria is increasing in southwest London associated with increasing travel from sub-Saharan Africa. Over the 25 year period there has been no improvement in chemoprophylaxis rates or time to diagnosis.

Prevention of malaria in children

Although malaria kills approximately 1 million children each year, preventive measures can be effective in limiting the mortality and morbidity associated with malaria. Mosquito bites can be avoided by use of appropriate environmental control and use of protective clothing, bed nets, repellents, and insecticide. Chemoprophylaxis is a mainstay of malaria prevention, and new, effective agents are increasingly available. Rapid, accurate diagnosis and effective medical treatment can help people who become ill with malaria despite their preventive efforts. With careful attention to preventive efforts, malaria should be extremely rare in travelers; similarly, broader implementation of preventive measures could decrease the burden of malaria on residents in areas where it is endemic.

The potential utility of the Semi-Nested Multiplex PCR technique for the diagnosis and investigation of congenital malaria

We report three cases of congenital malaria involving two malarial immune mothers living in Spain. Diagnostic PCR and Genotyping PCR for merozoite surface proteins 1 and 2 were essential to show that mothers and new-borns had different Plasmodium population parasites at the moment of the delivery, and that the infection was acquired earlier in gestation by transplacental transmission. In the first case the Plasmodium species founded in both, mother and child were different. Malaria in the twins showed a mixed infection (P. falciparum plus P. malariae) while the mother presented a P. falciparum infection. These facts were confirmed studying the polymorphisms for MSP1 and MSP2. Blood samples of the newborns were analyzed an half hour after delivery excluding the possibility of re-infection by mosquito bite and indicating a vertical transmission during pregnancy.