Malaria Surveillance - United States, 2016

Epidemiological characteristics of imported malaria related to international travel in the Republic of Korea from 2009 to 2018

Malaria, transmitted by mosquitoes infected with Plasmodium parasites, remains a significant health issue with global travel increasing the risk of imported malaria. This study investigates imported malaria cases in the Republic of Korea from 2009 to 2018 using data from the Korea National Infectious Disease Surveillance System. During this period, 601 imported cases were reported, with 82.4% male patients and a median age of 39.1 years. Most cases (76.5%) involved Korean residents returning from malaria-endemic areas, mainly Africa and Asia. Plasmodium falciparum (55.7%) and Plasmodium vivax (30.3%) were the predominant species. The annual percent change in incidence rate was 6.45%. Notably, 71.5% of the patients did not receive prophylactic chemotherapy, and 18% of those who did still developed malaria. Median diagnostic delays were 4 days for P. falciparum and 7 days for P. vivax. The case fatality rate was 2.3%, with all deaths occurring in travelers who contracted P. falciparum in Africa. This study emphasizes the ongoing risk of imported malaria in the ROK and highlights the need for better awareness and preventive measures among travelers. Enhancing surveillance and educating travelers on anti-malaria chemoprophylaxis are crucial.

Laboratory detection of donors implicated in transfusion-transmitted malaria

BACKGROUND

Transfusion-transmitted malaria (TTM) is rare in non-endemic areas (non-EAs) but can potentially be fatal. This review analyzes the laboratory results of donors causing TTM in non-EAs, to assess the detectability of their Plasmodium infection by molecular or antibody tests.

STUDY DESIGN AND METHODS

TTM cases in the United States, Canada, and Europe since 2010 were identified through a literature review. Authors and laboratories were contacted for missing details about sample types and laboratory methods. Results of Plasmodium polymerase chain reaction (PCR) and antibody tests were summarized.

RESULTS

Twelve cases of TTM and one bone marrow transplant transmission were identified. Of the 13 source donors, 12 were tested by PCR, 10 were positive on at least one sample; the 2 negative donors were tested only on retained segments of blood refrigerated for several weeks. All donors were PCR positive on a fresh sample except one who was positive on a retained but not a fresh sample. These PCRs targeted Plasmodium DNA with sensitivities in the range of 1000-10,000 parasites/mL. Antibody EIA was positive in only three of seven donors tested.

DISCUSSION

This review found that antibody EIAs failed to detect four of the seven TTM donors tested. DNA-based PCRs were able to detect Plasmodium infection in all donors tested except for two tested only on samples likely to have deteriorated from prolonged storage. Recently developed ribosomal RNA-based molecular donor screening assays are approximately 1000 fold more sensitive than these DNA-based PCRs, holding promise as a potential method to further reduce TTM.

Establishment and evaluation of a qPCR method for the detection of pfmdr1 mutations in Plasmodium falciparum, the causal agent of fatal malaria

Drug resistance surveillance is a major integral part of malaria control programs. Molecular methods play a pivotal role in drug resistance detection and related molecular research. This study aimed to develop a rapid and accurate detection method for drug resistance of Plasmodium falciparum (P. falciparum). A quantitative real-time PCR (qPCR) assay has been developed that identifies the mutation at locus A256T in the P.falciparum multi-drug resistance(pfmdr1) gene producing amino acid change at position 86. The results of 198 samples detected by qPCR were consistent with nested PCR and sequencing, giving an accuracy of 94.3%. The sensitivity, specificity, positive and negative predictive value of qPCR were 85.7%, 97.6%, 90.0% and 96.4%, respectively. The results of qPCR are basically consistent with the nested PCR, which is expected to replace the nested PCR as a new molecular biological method for drug resistance detection, providing reliable technical support for global malaria prevention and control.

Optimal malarial screening strategy in Australian blood donors: A cost-effectiveness analysis

BACKGROUND AND OBJECTIVES

The risk of transfusion-transmitted malaria (TTM) infections is extremely low in Australia, and the cost-effectiveness of the current screening strategy has not been assessed. This study aims to conduct a cost-effectiveness analysis of different malaria screening strategies in blood donors as part of the risk-based decision-making framework.

MATERIALS AND METHODS

A decision tree model was developed to assess the cost-effectiveness of five alternative malaria screening strategies from a healthcare sector perspective. Screening strategies combining total or partial removal of malaria testing with different deferral periods were considered. The probabilities of developing severe and uncomplicated TTM were based on a literature review of cases in non-endemic areas since 2000. The health outcomes were quantified using disability-adjusted life years. The costs of non-returning donors due to deferral were also included. Deterministic and probabilistic sensitivity analyses were conducted to account for data uncertainty.

RESULTS

The residual risks for all strategies were so low that the costs, mortality and morbidity associated with TTM are almost negligible. The overall costs were predominantly influenced by the costs of non-returning blood donors. As a result, removal of malaria testing and applying a 28-day deferral for at-risk donors were the least costly and most cost-effective of all the options considered.

CONCLUSION

The current screening strategy for malaria in blood donors in Australia is not an efficient use of healthcare resources. Partial or total removal of malaria testing would bring significant cost savings without significantly compromising blood safety.

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.

Canadian Blood Services traceback investigation of a suspected case of transfusion-transmitted malaria

BACKGROUND

A 4-month-old infant hospitalized since birth received multiple blood transfusions. In March 2022, Plasmodium falciparum was confirmed with nucleic acid testing. As the mother was assessed as unlikely to be the source of infection, the blood operator initiated a traceback investigation for a potential blood donor source. The patient had received 13 red blood cell (RBC) transfusions (aliquoted from 11 donors), 4 apheresis platelet (PLT) transfusions and 16 buffy coat pooled PLT transfusions. The blood operator medical team developed a supplementary malaria infection risk questionnaire to identify donors at highest risk of life-time malaria infection, based on birthplace, residence, or travel in malaria-endemic regions.

RESULTS

With 79 donors initially implicated, initial focus was on donors of RBC components. The 11 RBC donors were contacted and assessed using the supplementary questionnaire. Three donors, all of whom met current malaria-related donor eligibility criteria, were deemed high risk of prior malaria infection. These donors consented to P. falciparum serology and nucleic acid testing (NAT). One donor who was born and had resided in an endemic West African country for 14 years, was positive for P. falciparum by serology (indirect fluorescent antibody test) and NAT-(Ct ≥32). Lookback of this donor's transfused fresh co-components and prior donation identified no other malaria cases.

CONCLUSION

This was a probable transfusion-transmitted malaria (TTM) case from an eligible donor who in retrospect was found to have unrecognized, asymptomatic, semi-immune malaria infection, and who was potentially infectious. Blood donor lack of recall of prior malaria infection does not negate the risk of TTM from those who have lived in malaria-endemic countries.

Epidemiological shifts: the emergence of malaria in America

Plasmodium is a genus of parasites that comprises different species. The species falciparum, vivax, malariae, ovale, and knowlesi are known to cause a vector-borne illness called malaria, and among these, falciparum is known to cause major complications. The vector, the Anopheles mosquito, is commonly found in warmer regions close to the equator, and hence transmission and numbers of cases tend to be higher in Sub-Saharan Africa, South Asia, and Central America. The number of cases of malaria in the United States has remained stable over the years with low transmission rates, and the disease is mostly seen in the population with a recent travel history to endemic regions. The main reason behind this besides the weather conditions is that economically developed countries have eliminated mosquitos. However, there have been reports of locally reported cases with Plasmodium vivax in areas such as Florida and Texas in patients with no known travel history. This paper aims to familiarize US physicians with the pathophysiology, clinical features, and diagnostic modalities of malaria, as well as available treatment options.

A malaria death due to an imported Plasmodium falciparum infection in Sri Lanka during the prevention of re-establishment phase of malaria

BACKGROUND

Sri Lanka has maintained a rigorous programme to prevent the re-establishment of malaria ever since the disease was eliminated in October 2012. It includes efforts to sustain case surveillance to ensure early diagnosis and management of malaria. Yet, in April of 2023 the death occurred of an individual with imported malaria.

CASE PRESENTATION

The deceased was a 37-year-old Sri Lankan male who returned to Sri Lanka on the 10th of April after a business trip to several countries including Tanzania. He was febrile on arrival and consulted three Allopathic Medical Practitioners in succession in his home town in the Western Province of Sri Lanka, over a period of 5 days starting from the very day that he arrived in the country. Malaria was not tested for at any of these consultations and his clinical condition deteriorated. On the evening of 14th of April he was admitted to the medical intensive care unit of a major private hospital in the capital city of Colombo with multiple organ failure. There, on a request by the treating physician blood was tested for malaria and reported early the next morning as Plasmodium falciparum malaria with a high parasitaemia (> 10%). The patient died shortly after on the 15th of April before any anti-malarial medication was administered. The deceased had been a frequent business traveller to Africa, but with no past history of malaria. He had not taken chemoprophylaxis for malaria on this or previous travels to Africa.

DISCUSSION

The patient's P. falciparum infection progressed rapidly over 5 days of arriving in Sri Lanka leading to severe malaria without being diagnosed, despite him seeking healthcare from three different Medical Practitioners. Finally, a diagnosis of malaria was made on admission to an intensive care unit; the patient died before anti-malarial medicines were administered.

CONCLUSIONS

This first death due to severe P. falciparum malaria reported in Sri Lanka after elimination of the disease was due to the delay in diagnosing malaria.

Barriers to Timely Diagnosis and Treatment of Vector-Borne Diseases in a Changing Climate: A Case Report

This case study examined current trends in the prevalence of vector-borne diseases and the impact of climate change on disease distribution. Our findings indicate that the dynamics of the Anopheles mosquito population in particular has changed dramatically in the past decade and now poses an increasing threat to human populations previously at low risk for malaria transmission. Given their geographic location and propensity for sustaining vector-borne disease outbreaks, southeastern states are particularly vulnerable to climate-induced changes in vector populations. We demonstrate the need to strengthen our hospital and laboratory infrastructure prior to further increases in the incidence of vector-borne diseases by discussing a case of uncomplicated malaria in a patient who arrived in one of our hospitals in Louisiana. This case exemplifies a delay in diagnosis and obtaining appropriate treatment in a timely manner, which suggests that our current health care infrastructure, especially in areas heavily affected by climate change, may not be adequately prepared to protect patients from vector-borne diseases. We conclude our discussion by examining current laboratory protocols in place with suggestions for future actions to combat this increasing threat to public health in the United States.

Malaria Surveillance — United States, 2018

Problem/Condition

Malaria in humans is caused by intraerythrocytic protozoa of the genus Plasmodium. These parasites are transmitted by the bite of an infective female Anopheles species mosquito. Most malaria infections in the United States and its territories occur among persons who have traveled to regions with ongoing malaria transmission. However, among persons who have not traveled out of the country, malaria is occasionally acquired through exposure to infected blood or tissues, congenital transmission, nosocomial exposure, or local mosquitoborne transmission. Malaria surveillance in the United States and its territories provides information on its occurrence (e.g., temporal, geographic, and demographic), guides prevention and treatment recommendations for travelers and patients, and facilitates rapid transmission control measures if locally acquired cases are identified.

Period Covered

This report summarizes confirmed malaria cases in persons with onset of illness in 2018 and trends in previous years.

Description of System

Malaria cases diagnosed by blood smear microscopy, polymerase chain reaction, or rapid diagnostic tests are reported to local and state health departments through electronic laboratory reports or by health care providers or laboratory staff members directly reporting to CDC or health departments. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS), the National Notifiable Diseases Surveillance System (NNDSS), or direct CDC clinical consultations. CDC reference laboratories provide diagnostic assistance and conduct antimalarial drug resistance marker testing on blood specimens submitted by health care providers or local or state health departments. This report summarizes data from the integration of all cases from NMSS and NNDSS, CDC clinical consultations, and CDC reference laboratory reports.

Results

CDC received reports of 1,823 confirmed malaria cases with onset of symptoms in 2018, including one cryptic case and one case acquired through a bone marrow transplant. The number of cases reported in 2018 is 15.6% fewer than in 2017. The number of cases diagnosed in the United States and its territories has been increasing since the mid-1970s; the number of cases reported in 2017 was the highest since 1972. Of the cases in 2018, a total of 1,519 (85.0%) were imported cases that originated from Africa; 1,061 (69.9%) of the cases from Africa were from West Africa, a similar proportion to what was observed in 2017. Among all cases, P. falciparum accounted for most infections (1,273 [69.8%]), followed by P. vivax (173 [9.5%]), P. ovale (95 [5.2%]), and P. malariae (48 [2.6%]). For the first time since 2008, an imported case of P. knowlesi was identified in the United States and its territories. Infections by two or more species accounted for 17 cases (<1.0%). The infecting species was not reported or was undetermined in 216 cases (11.9%). Most patients (92.6%) had symptom onset <90 days after returning to the United States or its territories from a country with malaria transmission. Of the U.S. civilian patients who reported reason for travel, 77.0% were visiting friends and relatives. Chemoprophylaxis with antimalarial medications are recommended for U.S. residents to prevent malaria while traveling in countries where it is endemic. Fewer U.S. residents with imported malaria reported taking any malaria chemoprophylaxis in 2018 (24.5%) than in 2017 (28.4%), and adherence was poor among those who took chemoprophylaxis. Among the 864 U.S. residents with malaria for whom information on chemoprophylaxis use and travel region were known, 95.0% did not adhere to or did not take a CDC-recommended chemoprophylaxis regimen. Among 683 women with malaria, 19 reported being pregnant. Of these, 11 pregnant women were U.S. residents, and one of whom reported taking chemoprophylaxis to prevent malaria but her adherence to chemoprophylaxis was not reported. Thirty-eight (2.1%) malaria cases occurred among U.S. military personnel in 2018, more than in 2017 (26 [1.2%]). Among all reported malaria cases in 2018, a total of 251 (13.8%) were classified as severe malaria illness, and seven persons died from malaria. In 2018, CDC analyzed 106 P. falciparum-positive and four P. falciparum mixed species specimens for antimalarial resistance markers (although certain loci were untestable in some specimens); identification of genetic polymorphisms associated with resistance to pyrimethamine were found in 99 (98.0%), to sulfadoxine in 49 (49.6%), to chloroquine in 50 (45.5%), and to mefloquine in two (2.0%); no specimens tested contained a marker for atovaquone or artemisinin resistance.

Interpretation

The importation of malaria reflects the overall trends in global travel to and from areas where malaria is endemic, and 15.6% fewer cases were imported in 2018 compared with 2017. Of imported cases, 59.3% were among persons who had traveled from West Africa. Among U.S. civilians, visiting friends and relatives was the most common reason for travel (77.1%).

Public Health Actions

The best way for U.S. residents to prevent malaria is to take chemoprophylaxis medication before, during, and after travel to a country where malaria is endemic. Adherence to recommended malaria prevention strategies among U.S. travelers would reduce the number of imported cases. Reported reasons for nonadherence include prematurely stopping after leaving the area where malaria was endemic, forgetting to take the medication, and experiencing a side effect. Health care providers can make travelers aware of the risks posed by malaria and incorporate education to motivate them to be adherent to chemoprophylaxis. Malaria infections can be fatal if not diagnosed and treated promptly with antimalarial medications appropriate for the patient’s age, pregnancy status, medical history, the likely country of malaria acquisition, and previous use of antimalarial chemoprophylaxis. Antimalarial use for chemoprophylaxis and treatment should be determined by the CDC guidelines, which are frequently updated. In April 2019, intravenous (IV) artesunate became the first-line medication for treatment of severe malaria in the United States and its territories. Artesunate was approved by the Food and Drug Administration (FDA) in 2020 and is commercially available (Artesunate for Injection) from major U.S. drug distributors (https://amivas.com). Stocking IV artesunate locally allows for immediate treatment of severe malaria once diagnosed and provides patients with the best chance of a complete recovery and no sequelae. With commercial IV artesunate now available, CDC will discontinue distribution of non–FDA-approved IV artesunate under an investigational new drug protocol on September 30, 2022. Detailed recommendations for preventing malaria are online at https://www.cdc.gov/malaria/travelers/drugs.html. Malaria diagnosis and treatment recommendations are also available online at https://www.cdc.gov/malaria/diagnosis_treatment. Health care providers who have sought urgent infectious disease consultation and require additional assistance on diagnosis and treatment of malaria can call the Malaria Hotline 9:00 a.m.–5:00 p.m. Eastern Time, Monday–Friday, at 770-488-7788 or 855-856-4713 or after hours for urgent inquiries at 770-488-7100. Persons submitting malaria case reports (care providers, laboratories, and state and local public health officials) should provide complete information because incomplete reporting compromises case investigations and public health efforts to prevent future infections and examine trends in malaria cases. Molecular surveillance of antimalarial drug resistance markers enables CDC to track, guide treatment, and manage drug resistance in malaria parasites both domestically and globally. A greater proportion of specimens from domestic malaria cases are needed to improve the completeness of antimalarial drug resistance analysis; therefore, CDC requests that blood specimens be submitted for any case of malaria diagnosed in the United States and its territories.

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.

Diagnosis, Treatment, and Prevention of Malaria in the US: A Review

IMPORTANCE

Malaria is caused by protozoa parasites of the genus Plasmodium and is diagnosed in approximately 2000 people in the US each year who have returned from visiting regions with endemic malaria. The mortality rate from malaria is approximately 0.3% in the US and 0.26% worldwide.

OBSERVATIONS

In the US, most malaria is diagnosed in people who traveled to an endemic region. More than 80% of people diagnosed with malaria in the US acquired the infection in Africa. Of the approximately 2000 people diagnosed with malaria in the US in 2017, an estimated 82.4% were adults and about 78.6% were Black or African American. Among US residents diagnosed with malaria, 71.7% had not taken malaria chemoprophylaxis during travel. In 2017 in the US, P falciparum was the species diagnosed in approximately 79% of patients, whereas P vivax was diagnosed in an estimated 11.2% of patients. In 2017 in the US, severe malaria, defined as vital organ involvement including shock, pulmonary edema, significant bleeding, seizures, impaired consciousness, and laboratory abnormalities such as kidney impairment, acidosis, anemia, or high parasitemia, occurred in approximately 14% of patients, and an estimated 0.3% of those receiving a diagnosis of malaria in the US died. P falciparum has developed resistance to chloroquine in most regions of the world, including Africa. First-line therapy for P falciparum malaria in the US is combination therapy that includes artemisinin. If P falciparum was acquired in a known chloroquine-sensitive region such as Haiti, chloroquine remains an alternative option. When artemisinin-based combination therapies are not available, atovaquone-proguanil or quinine plus clindamycin is used for chloroquine-resistant malaria. P vivax, P ovale, P malariae, and P knowlesi are typically chloroquine sensitive, and treatment with either artemisinin-based combination therapy or chloroquine for regions with chloroquine-susceptible infections for uncomplicated malaria is recommended. For severe malaria, intravenous artesunate is first-line therapy. Treatment of mild malaria due to a chloroquine-resistant parasite consists of a combination therapy that includes artemisinin or chloroquine for chloroquine-sensitive malaria. P vivax and P ovale require additional therapy with an 8-aminoquinoline to eradicate the liver stage. Several options exist for chemoprophylaxis and selection should be based on patient characteristics and preferences.

CONCLUSIONS AND RELEVANCE

Approximately 2000 cases of malaria are diagnosed each year in the US, most commonly in travelers returning from visiting endemic areas. Prevention and treatment of malaria depend on the species and the drug sensitivity of parasites from the region of acquisition. Intravenous artesunate is first-line therapy for severe malaria.

Plasmodium falciparum 7G8 challenge provides conservative prediction of efficacy of PfNF54-based PfSPZ Vaccine in Africa

Controlled human malaria infection (CHMI) has supported Plasmodium falciparum (Pf) malaria vaccine development by providing preliminary estimates of vaccine efficacy (VE). Because CHMIs generally use Pf strains similar to vaccine strains, VE against antigenically heterogeneous Pf in the field has been required to establish VE. We increased the stringency of CHMI by selecting a Brazilian isolate, Pf7G8, which is genetically distant from the West African parasite (PfNF54) in our PfSPZ vaccines. Using two regimens to identically immunize US and Malian adults, VE over 24 weeks in the field was as good as or better than VE against CHMI at 24 weeks in the US. To explain this finding, here we quantify differences in the genome, proteome, and predicted CD8 T cell epitopes of PfNF54 relative to 704 Pf isolates from Africa and Pf7G8. We show that Pf7G8 is more distant from PfNF54 than any African isolates tested. We propose VE against Pf7G8 CHMI for providing pivotal data for malaria vaccine licensure for travelers to Africa, and potentially for endemic populations, because the genetic distance of Pf7G8 from the Pf vaccine strain makes it a stringent surrogate for Pf parasites in Africa.

Here the authors show that controlled human malaria infection with a Brazilian parasite highly divergent from vaccine and West African field strains can provide estimates of vaccine efficacy in Mali, and could replace field testing, streamlining vaccine development.

Robust inactivation of Plasmodium falciparum in red blood cell concentrates using amustaline and glutathione pathogen reduction

BACKGROUND

Plasmodium falciparum is the parasite responsible for most malaria cases globally. The risk of transfusion-transmitted malaria (TTM) is mitigated by donor deferrals and blood screening strategies, which adversely impact blood availability. Previous studies showed robust inactivation of P. falciparum using nucleic acid-targeting pathogen reduction technologies (PRT) for the treatment of plasma and platelet components or whole blood (WB). The efficacy of the amustaline-glutathione (GSH) PRT to inactivate P. falciparum is here evaluated in red blood cells (RBC), as well the impact of PRT on parasite loads, stages, and strains.

STUDY DESIGN AND METHODS

RBC units resuspended in AS-1 or AS-5 additive solutions were spiked with ring stage-infected RBC and treated with the amustaline-GSH PRT. Parasite loads and viability were measured in samples at the time of contamination, and after treatment, using serial 10-fold dilutions of the samples in RBC cultures maintained for up to 4 weeks.

RESULTS

P. falciparum viability assays allow for the detection of very low levels of parasite. Initial parasite titer was >5.2 log₁₀ /ml in AS-1/5 RBC. No infectious parasites were detected in amustaline-GSH-treated samples after 4 weeks of culture. Amustaline-GSH inactivated high parasite loads regardless of parasite stages and strains. Amustaline readily penetrates the parasite, irreversibly blocks development, and leads to parasite death and expulsion from RBC.

DISCUSSION

Amustaline-GSH PRT demonstrated robust efficacy to inactivate malaria parasites in RBC concentrates. This study completes the portfolio of studies demonstrating the efficacy of nucleic acid-targeting PRTs to mitigate TTM risks as previously reported for platelet concentrates, plasma, and WB.

Symptomatic Plasmodium vivax Infection in Rwanda

We report a Plasmodium vivax infection in a Rwandan child misdiagnosed with Plasmodium falciparum and administered artemether-lumefantrine. Antigen detection revealed an absence of P falciparum histidine-rich protein 2 (HRP2) and presence of Plasmodium vivax lactate dehydrogenase. Nested and real-time polymerase chain reactions verified that the sample only contained P vivax deoxyribonucleic acid.

Pediatric Malaria: Global and North American Perspectives

Malaria is a leading cause of death in children less than 5 years of age globally, and a common cause of fever in the returning North American traveler. New tools in the fight against malaria have been developed over the past decades: potent artemisinin derivatives; rapid diagnostic tests; long-lasting insecticidal bed nets; and a new vaccine, RTS,S/AS01. Thwarting these advances, parasite and Anopheles vector resistance are emerging. In the meantime, clinicians will continue to see malaria among febrile travelers from the tropics. Early recognition, diagnosis, and treatment can be lifesaving, but rely on the vigilance of frontline clinicians.

Transfusion-Transmitted Malaria and Mitigation Strategies in Nonendemic Regions

Background

Malaria is a mosquito-borne infectious disease caused by protozoan parasites of the genus Plasmodium. These parasites can be transmitted by blood transfusion especially through Red Cell Blood Concentrates collected from asymptomatic and parasitemic donors. As migration of populations from endemic areas to Europe and overseas recreational travel to endemic regions increase, there is growing risk of transfusion-transmitted malaria (TTM) in nonendemic regions of the world. The present work provides an overview of the mitigation strategies in nonendemic countries and their effectiveness and discusses possible approaches to evolve the strategies in order to maintain both a safe and adequate blood supply.

Summary

The historical and current situation of malaria and TTM in Europe and on the North American continent are described. The infectivity of Plasmodium in blood components and the consequences of TTM are presented, along with the regulations and guidelines for TTM mitigation in Europe, USA, and Canada. The regulations/guidelines currently in place in Europe allow a certain amount of leeway for local policies. A questionnaire was used to survey European countries regarding their current strategies and recent TTM cases. From the questionnaire and published cases, approximately 20 cases of TTM were identified in the past 20 years in the USA and Europe. The vast majority of implicated donors have been former residents of malaria-endemic areas, particularly former residents of hyperendemic areas in Africa. The most recent TTM cases are discussed in detail to provide insight into the gaps in current strategies. The utility and uncertainties of pathogen reduction and serological and molecular testing methods are discussed.

Key Messages

Overall, the risk of transfusion-associated malaria in nonendemic countries is considered to be low and very few TTM cases occurred in these regions in the last 20 years. The questionnaire-based strategy with questions about risk in relation to malaria exposure with or without selective testing based on questioning seems to be relatively effective, although rare and sometimes fatal transmissions still occur. An outstanding question is whether in the future molecular methods may further improve the safety of blood products and help constrain the loss of donors.

Safety and Effectiveness of Intravenous Artesunate for Treatment of Severe Malaria in the United States-April 2019 Through December 2020

BACKGROUND

Severe malaria can be deadly and requires treatment with intravenous artesunate (IVAS). The Centers for Disease Control and Prevention provided IVAS starting 1 April 2019 for all patients with severe malaria in the United States. This study describes the safety and effectiveness of IVAS in these patients.

METHODS

Patients meeting criteria for severe malaria April 2019-December 2020 who received IVAS were included. Demographic, clinical, laboratory, adverse event, and outcome information were collected. Clinical presentation, time to reach 1% and 0% parasitemia, adverse events, and death were described using proportions, medians, interquartile range (IQR), and tests of significance for differences in proportions.

RESULTS

Of 280 patients included, the majority were male (61.4%), Black (75.0%), with a median age of 35 years (IQR: 15.8-53.9). Most had Plasmodium falciparum (83.6%) with median parasitemia of 8.0% (IQR: 4.6-13.2). Of 170 patients with information, 159 (93.5%) reached ≤1% parasitemia by the third IVAS dose with a median time of 17.6 hours (IQR: 10.8-28.8), and 0% parasitemia in a median of 37.2 hours (IQR 27.2-55.2). Patients with parasite densities >10% and those requiring adjunct therapy had significantly higher parasite clearance times. Adverse events associated with IVAS were reported in 4.8% (n = 13 of 271). Eight patients had post-artesunate delayed hemolysis that resolved. There were 5 (1.8%) deaths, all attributable to severe malaria.

CONCLUSIONS

IVAS is a safe and effective drug for the treatment of severe malaria in the United States; timely administration can be lifesaving.

Transfusion-Transmitted Malaria: Two Pediatric Cases From the United States and Their Relevance in an Increasingly Globalized World

In non-endemic settings, transfusion-transmitted malaria (TTM) is rare but potentially fatal and becoming more common with globalization. We present two pediatric cases that demonstrate donor screening using questionnaires is subject to error and that TTM should be considered with fever following numerous transfusions in children, particularly sickle cell patients.

An update on prevention of malaria in travelers

Malaria, a parasitic disease caused by protozoa belonging to the genus Plasmodium, continues to represent a formidable public health challenge. Despite being a preventable disease, cases reported among travelers have continued to increase in recent decades. Protection of travelers against malaria, a potentially life-threatening disease, is of paramount importance, and it is therefore necessary for healthcare professionals to be up to date with the most recent recommendations. The present review provides an update of the existent measures for malaria prevention among travelers.

Imported malaria in metropolitan France, from recommendations to clinical practice - proposal for improvement

BACKGROUND

Approximately 5000 cases of imported malaria are observed each year in metropolitan France. Guidelines for the prevention and management of imported malaria were published by the French infectious disease society (French acronym SPILF) in 2017.

OBJECTIVE

Study objective was to describe in a retrospective analysis (2015-2016) imported malaria cases recorded in a Parisian hospital, to analyze the congruence to previous guidelines (2014), deviation in respect to post hoc published guidelines and potential areas for improvement.

RESULTS

Two hundred and one cases were analyzed using medical charts. There was a majority of men (sex ratio 2/1), with a mean age of 43 years at diagnosis. The main area of infection acquisition was sub-Saharan Africa (97%). The average time since return from the endemic area was 20 days. Patients consulted the emergency department for flu-like syndrome (32%), fever or chills (28%), and gastrointestinal symptoms (22%). Blood smears mainly identified Plasmodium falciparum (n=180, 90%). There were 52 (26%) severe malaria episodes.

CONCLUSION

The analysis of national guideline adequacy highlighted difficulties in obtaining a complete biological workup at baseline, managing patients with vomiting, and in the post-treatment follow-up.

The Pan African Vivax and Ovale Network (PAVON): Refocusing on Plasmodium vivax, ovale and asymptomatic malaria in sub-Saharan Africa

The recent World Malaria report shows that progress in malaria elimination has stalled. Current data acquisition by NMCPs depend on passive case detection and clinical reports focused mainly on Plasmodium falciparum (Pf). In recent times, several countries in sub-Saharan Africa have reported cases of Plasmodium vivax (Pv) with a considerable number being Duffy negative. The burden of Pv and Plasmodium ovale (Po) appear to be more than acknowledged. Similarly, the contribution of asymptomatic malaria in transmission is hardly considered by NMCPs in Africa. Inclusion of these as targets in malaria elimination agenda is necessary to achieve elimination goal, as these harbor hypnozoites. The Pan African Vivax and Ovale Network (PAVON) is a new consortium of African Scientists working in Africa on the transmission profile of Pv and Po. The group collaborates with African NMCPs to train in Plasmodium molecular diagnostics, microscopy, and interpretation of molecular data from active surveys to translate into policy. Details of the mission, rational and modus operandi of the group are outlined.

Malaria in Pregnancy: Considerations for Health Care Providers in Nonendemic Countries

Malaria is a common infection world-wide, which carries significant risk of morbidity and mortality. Health care providers in the United States may lack experience in recognizing and treating this disease. The pathophysiology of malaria differs during pregnancy, resulting in increased risk for serious morbidity and mortality for the woman and her fetus. Screening for risk factors, especially immigration from and travel to endemic countries, is critical. Symptoms of malaria can mimic influenza-type illnesses, causing delay in diagnosis. Consultation with an infectious disease specialist and hospitalization may be required for appropriate testing and treatment. Chemoprophylaxis and counseling regarding methods to reduce risk are important components of prevention. The US Centers for Disease Control and Prevention and the World Health Organization have established protocols for treatment and are helpful resources for clinicians. A team approach to care based on the woman's stage of illness and recovery, can involve midwives, physicians, specialists and others.

Plasmodium ovale wallikeri and P. ovale curtisi Infections and Diagnostic Approaches to Imported Malaria, France, 2013-2018

Patients infected with P. ovale wallikeri displayed deeper thrombocytopenia and a shorter latency period.

We retrospectively analyzed epidemiologic, clinical, and biologic characteristics of 368 Plasmodium ovale wallikeri and 309 P. ovale curtisi infections treated in France during January 2013–December 2018. P. ovale wallikeri infections displayed deeper thrombocytopenia and shorter latency periods. Despite similar clinical manifestations, P. ovale wallikeri–infected patients were more frequently treated with artemisinin-based combination therapy. Although the difference was not statistically significant, P. ovale wallikeri–infected patients were 5 times more frequently hospitalized in intensive care or intermediate care and had a higher proportion of severe thrombocytopenia than P. ovale curtisi–infected patients. Rapid diagnostic tests that detect aldolase were more efficient than those detecting Plasmodium lactate dehydrogenase. Sequence analysis of the potra gene from 90 P. ovale isolates reveals an insufficient polymorphism for relapse typing.

Detection of malaria parasites in samples from returning US travelers using the Alethia® Malaria Plus LAMP assay

Objective

In this study, the performance of a commercially available malaria LAMP assay (Alethia® Malaria Plus LAMP) was evaluated using retrospective clinical samples obtained from travelers returning to the United States of America (USA). Recently, several laboratories in non-malaria endemic countries evaluated the use of the loop mediated isothermal amplification (LAMP) assays for the diagnosis of imported malaria cases. These tests are simpler than polymerase-chain reaction (PCR)-based assays and were shown to have high sensitivity. Much of malaria diagnoses in the USA, is undertaken at the state level using mainly microscopy and rapid diagnostic tests (RDTs). However, molecular tools offer greater sensitivity over microscopy and RDTs. A reliable, easy to perform molecular assay can provide a test of choice for the accurate detection of malaria parasites in places where expert microscopy is lacking and/or for the detection of low-parasite density infections.

Results

The Alethia® Malaria Plus LAMP assay was easy to use, had similar test performances as the real-time PCR reference test and results were obtained faster (within 1 h) than the reference test. The sensitivity of the assay was 100% with a kappa score of 1 when compared to the reference PET-PCR assay.

Current methods for the detection of antimalarial drug resistance in Plasmodium parasites infecting humans

Malaria is the world's deadliest parasitic disease. Great progress has been made in the fight against malaria over the past two decades, but this has recently begun to plateau, in part due to the global development of antimalarial drug resistance. The ability to track drug resistance is necessary to achieve progress in treatment, disease surveillance and epidemiology, which has prompted the development of advanced diagnostic methods. These new methods provide unprecedented access to information that can help to guide public health policies. Development of new technologies increases the potential for high throughput and reduced costs of diagnostic tests; improving the accessibility of tools to investigate the forces driving disease dynamics and, ultimately, clinical outcomes for malaria patients and public health. This literature review provides a summary of the methods currently available for the detection of antimalarial drug resistance from the examination of patients' blood samples. While no single method is perfect for every application, many of the newly developed methods give promise for more reliable and efficient characterisation of Plasmodium resistance in a range of settings. By exploiting the strengths of the tools available, we can develop a deeper understanding of the evolutionary and spatiotemporal dynamics of this disease. This will translate into more effective disease control, better-informed policy, and more timely and successful treatment for malaria patients.

Malaria Surveillance - United States, 2017

PROBLEM/CONDITION

Malaria in humans is caused by intraerythrocytic protozoa of the genus Plasmodium. These parasites are transmitted by the bite of an infective female Anopheles species mosquito. The majority of malaria infections in the United States occur among persons who have traveled to regions with ongoing malaria transmission. However, malaria is occasionally acquired by persons who have not traveled out of the country through exposure to infected blood products, congenital transmission, nosocomial exposure, or local mosquitoborne transmission. Malaria surveillance in the United States is conducted to provide information on its occurrence (e.g., temporal, geographic, and demographic), guide prevention and treatment recommendations for travelers and patients, and facilitate rapid transmission control measures if locally acquired cases are identified.

PERIOD COVERED

This report summarizes confirmed malaria cases in persons with onset of illness in 2017 and trends in previous years.

DESCRIPTION OF SYSTEM

Malaria cases diagnosed by blood film microscopy, polymerase chain reaction, or rapid diagnostic tests are reported to local and state health departments through electronic laboratory reports or by health care providers or laboratory staff members. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS), the National Notifiable Diseases Surveillance System (NNDSS), or direct CDC consultations. CDC reference laboratories provide diagnostic assistance and conduct antimalarial drug resistance marker testing on blood samples submitted by health care providers or local or state health departments. This report summarizes data from the integration of all cases from NMSS and NNDSS, CDC reference laboratory reports, and CDC clinical consultations.

RESULTS

CDC received reports of 2,161 confirmed malaria cases with onset of symptoms in 2017, including two congenital cases, three cryptic cases, and two cases acquired through blood transfusion. The number of malaria cases diagnosed in the United States has been increasing since the mid-1970s; in 2017, the number of cases reported was the highest in 45 years, surpassing the previous peak of 2,078 confirmed cases reported in 2016. Of the cases in 2017, a total of 1,819 (86.1%) were imported cases that originated from Africa; 1,216 (66.9%) of these came from West Africa. The overall proportion of imported cases originating from West Africa was greater in 2017 (57.6%) than in 2016 (51.6%). Among all cases, P. falciparum accounted for the majority of infections (1,523 [70.5%]), followed by P. vivax (216 [10.0%]), P. ovale (119 [5.5%]), and P. malariae (55 [2.6%]). Infections by two or more species accounted for 22 cases (1.0%). The infecting species was not reported or was undetermined in 226 cases (10.5%). CDC provided diagnostic assistance for 9.5% of confirmed cases and tested 8.0% of specimens with P. falciparum infections for antimalarial resistance markers. Most patients (94.8%) had symptom onset <90 days after returning to the United States from a country with malaria transmission. Of the U.S. civilian patients who reported reason for travel, 73.1% were visiting friends and relatives. The proportion of U.S. residents with malaria who reported taking any chemoprophylaxis in 2017 (28.4%) was similar to that in 2016 (26.4%), and adherence was poor among those who took chemoprophylaxis. Among the 996 U.S. residents with malaria for whom information on chemoprophylaxis use and travel region were known, 93.3% did not adhere to or did not take a CDC-recommended chemoprophylaxis regimen. Among 805 women with malaria, 27 reported being pregnant. Of these, 10 pregnant women were U.S. residents, and none reported taking chemoprophylaxis to prevent malaria. A total of 26 (1.2%) malaria cases occurred among U.S. military personnel in 2017, fewer than in 2016 (41 [2.0%]). Among all reported cases in 2017, a total of 312 (14.4%) were classified as severe malaria illnesses, and seven persons died. In 2017, CDC analyzed 117 P. falciparum-positive and six P. falciparum mixed-species samples for antimalarial resistance markers (although certain loci were untestable in some samples); identification of genetic polymorphisms associated with resistance to pyrimethamine were found in 108 (97.3%), to sulfadoxine in 77 (69.4%), to chloroquine in 38 (33.3%), to mefloquine in three (2.7%), and to atovaquone in three (2.7%); no specimens tested contained a marker for artemisinin resistance. The data completeness of key variables (species, country of acquisition, and resident status) was lower in 2017 (74.4%) than in 2016 (79.4%).

INTERPRETATION

The number of reported malaria cases in 2017 continued a decades-long increasing trend, and for the second year in a row the highest number of cases since 1971 have been reported. Despite progress in malaria control in recent years, the disease remains endemic in many areas globally. The importation of malaria reflects the overall increase in global travel to and from these areas. Fifty-six percent of all cases were among persons who had traveled from West Africa, and among U.S. civilians, visiting friends and relatives was the most common reason for travel (73.1%). Frequent international travel combined with the inadequate use of prevention measures by travelers resulted in the highest number of imported malaria cases detected in the United States in 4 decades.

PUBLIC HEALTH ACTIONS

The best way to prevent malaria is to take chemoprophylaxis medication during travel to a country where malaria is endemic. Adherence to recommended malaria prevention strategies among U.S. travelers would reduce the numbers of imported cases; reasons for nonadherence include prematurely stopping after leaving the area where malaria was endemic, forgetting to take the medication, and experiencing a side effect. Travelers might not understand the risk that malaria poses to them; thus, health care providers should incorporate risk education to motivate travelers to be adherent to chemoprophylaxis. Malaria infections can be fatal if not diagnosed and treated promptly with antimalarial medications appropriate for the patient's age, medical history, the likely country of malaria acquisition, and previous use of antimalarial chemoprophylaxis. Antimalarial use for chemoprophylaxis and treatment should be informed by the most recent guidelines, which are frequently updated. In 2018, two formulations of tafenoquine (i.e., Arakoda and Krintafel) were approved by the Food and Drug Administration (FDA) for use in the United States. Arakoda was approved for use by adults for chemoprophylaxis; the regimen requires a predeparture loading dose, taking the medication weekly during travel, and a short course posttravel. The Arakoda chemoprophylaxis regimen is shorter than alternative regimens, which could possibly improve adherence. This medication also might prevent relapses. Krintafel was approved for radical cure of P. vivax infections in those aged >16 years and should be co-administered with chloroquine (https://www.cdc.gov/malaria/new_info/2020/tafenoquine_2020.html). In April 2019, intravenous artesunate became the first-line medication for treatment of severe malaria in the United States. Artesunate was recently FDA approved but is not yet commercially available. The drug can be obtained from CDC under an investigational new drug protocol. Detailed recommendations for preventing malaria are available to the general public at the CDC website (https://www.cdc.gov/malaria/travelers/drugs.html). Health care providers should consult the CDC Guidelines for Treatment of Malaria in the United States and contact the CDC's Malaria Hotline for case management advice when needed. Malaria treatment recommendations are available online (https://www.cdc.gov/malaria/diagnosis_treatment) and from the Malaria Hotline (770-488-7788 or toll-free 855-856-4713). Persons submitting malaria case reports (care providers, laboratories, and state and local public health officials) should provide complete information because incomplete reporting compromises case investigations and efforts to prevent infections and examine trends in malaria cases. Molecular surveillance of antimalarial drug resistance markers (https://www.cdc.gov/malaria/features/ars.html) enables CDC to track, guide treatment, and manage drug resistance in malaria parasites both domestically and internationally. More samples are needed to improve the completeness of antimalarial drug resistance analysis; therefore, CDC requests that blood specimens be submitted for any case of malaria diagnosed in the United States.

Application of Epidemiological Geographic Information System: An Open-Source Spatial Analysis Tool Based on the OMOP Common Data Model

BACKGROUND

Spatial epidemiology is used to evaluate geographical variations and disparities in health outcomes; however, constructing geographic statistical models requires a labor-intensive process that limits the overall utility. We developed an open-source software for spatial epidemiological analysis and demonstrated its applicability and quality.

METHODS

Based on standardized geocode and observational health data, the Application of Epidemiological Geographic Information System (AEGIS) provides two spatial analysis methods: disease mapping and detecting clustered medical conditions and outcomes. The AEGIS assesses the geographical distribution of incidences and health outcomes in Korea and the United States, specifically incidence of cancers and their mortality rates, endemic malarial areas, and heart diseases (only the United States).

RESULTS

The AEGIS-generated spatial distribution of incident cancer in Korea was consistent with previous reports. The incidence of liver cancer in women with the highest Moran's I (0.44; p < 0.001) was 17.4 (10.3-26.9). The malarial endemic cluster was identified in Paju-si, Korea (p < 0.001). When the AEGIS was applied to the database of the United States, a heart disease cluster was appropriately identified (p < 0.001).

CONCLUSIONS

As an open-source, cross-country, spatial analytics solution, AEGIS may globally assess the differences in geographical distribution of health outcomes through the use of standardized geocode and observational health databases.

SARS-CoV-2 and Pregnancy: A Review of the Facts

OBJECTIVE

 The present comprehensive review aims to show the full extent of what is known to date and provide a more thorough view on the effects of SARS-CoV2 in pregnancy.

METHODS

 Between March 29 and May, 2020, the words COVID-19, SARS-CoV2, COVID-19 and pregnancy, SARS-CoV2 and pregnancy, and SARS and pregnancy were searched in the PubMed and Google Scholar databases; the guidelines from well-known societies and institutions (Royal College of Obstetricians and Gynaecologists [RCOG], American College of Obstetricians and Gynecologists [ACOG], International Society of Ultrasound in Obstetrics & Gynecology [ISUOG], Centers for Disease Control and Prevention [CDC], International Federation of Gynecology and Obstetrics [FIGO]) were also included.

CONCLUSION

 The COVID-19 outbreak resulted in a pandemic with > 3.3 million cases and 230 thousand deaths until May 2^nd. It is caused by the SARS-CoV2 virus and may lead to severe pulmonary infection and multi-organ failure. Past experiences show that unique characteristics in pregnancy make pregnant women more susceptible to complications from viral infections. Yet, this has not been reported with this new virus. There are risk factors that seem to increase morbidity in pregnancy, such as obesity (body mass index [BMI] > 35), asthma and cardiovascular disease. Current reports describe an increased rate of preterm birth and C-section. Vertical transmission is still a possibility, due to a few reported cases of neonatal positive real-time polymerase chain reaction (RT-PCR) in nasal swab, amniotic fluid, and positive immunoglobulin M (IgM) in neonatal blood. Treatments must be weighed in with caution due to the lack of quality trials that prove their effectiveness and safety during pregnancy. Medical staff must use personal protective equipment in handling SARS-CoV2 suspected or positive patients and be alert for respiratory decompensations.

An open label study of the safety and efficacy of a single dose of weekly chloroquine and azithromycin administered for malaria prophylaxis in healthy adults challenged with 7G8 chloroquine-resistant Plasmodium falciparum in a controlled human malaria infection model

Background

Malaria remains the top infectious disease threat facing the U.S. military in many forward operating environments. Compliance with malaria chemoprophylaxis remains a critical component in preventing malaria in the deployed Service Member. Studies of previous military operations show that compliance is consistently higher with weekly versus daily dosing regimens. Current FDA approved weekly chemoprophylaxis options have contraindications that can limit prescribing. The combination of chloroquine (CQ) with azithromycin (AZ) has previously been shown to be an efficacious treatment option for malaria, has pharmacokinetics compatible with weekly dosing, and has shown synergy when combined in vitro.

Methods

In this open label study, 18 healthy volunteers, aged 18–50 years (inclusive), were randomly assigned to receive either 300 mg CQ or 300 mg CQ and 2 gm azithromycin (CQAZ) of directly observed therapy, weekly for 3 weeks prior to undergoing mosquito bite challenge with chloroquine-resistant Plasmodium falciparum. Volunteers that remained asymptomatic and had no evidence of parasitaemia continued to receive weekly post-exposure chemoprophylaxis for 3 weeks following malaria challenge. The primary endpoint was the number of volunteers that remained asymptomatic and had no evidence of parasitaemia 28 days after the malaria challenge.

Results

All 6 (100%) volunteers randomized to the CQ control group became symptomatic with parasitaemia during the 28-day post-challenge period. Only 1/12 (8.3%) of volunteers in the CQAZ group developed symptoms and parasitaemia during the 28-day post-challenge period. However, after chemoprophylaxis was discontinued an additional 6 volunteers developed parasitaemia between days 28–41 after challenge, with 4 of 6 experiencing symptoms. 80% of subjects in the CQAZ group experienced treatment related gastrointestinal adverse events (including 13% that experienced severe nausea) compared to 38% in the CQ group. A comparison of the pharmacokinetics in the CQAZ group demonstrated higher azithromycin Cmax (p = 0.03) and AUC (p = 0.044) levels in those volunteers who never became parasitaemic compared to those who did.

Conclusion

Given the high rate of side effects and poor efficacy when administered for 3 weeks before and after challenge, the combination of weekly chloroquine and azithromycin is a suboptimal regimen combination for weekly malaria chemoprophylaxis.

Trial registration ClinicalTrials.gov NCT03278808

Oral manifestations related to malaria: A systematic review

OBJECTIVE

To generalize the oral manifestations related to malaria and discuss their clinical significance for health professionals.

MATERIALS AND METHODS

The bibliographic databases of Public MEDLINE, Embase, Web of Science and Scopus were employed to retrieve publications online from January 1781 to August 2019. Original research articles, clinical trials, and case reports published in English were included.

RESULTS

A small number of studies reported oral manifestations of malaria (n = 29), including gingival bleeding, glossitis, oral ulcer, abnormal oral pigmentation, pericoronitis, herpes labialis, herpes gingivostomatitis, bitter taste, sore throat, Burkitt lymphoma of the jaw, alveolar bone resorption, and enamel hypoplasia.

CONCLUSION

Oral manifestations may be important indicators for identification of malaria. Dental and general professionals should pay more attention to oral manifestations in malaria cases, and guide them for specialized examination, diagnosis, and management.

Polymorphism analysis of propeller domain of k13 gene in Plasmodium ovale curtisi and Plasmodium ovale wallikeri isolates original infection from Myanmar and Africa in Yunnan Province, China

BACKGROUND

Eighteen imported ovale malaria cases imported from Myanmar and various African countries have been reported in Yunnan Province, China from 2013 to 2018. All of them have been confirmed by morphological examination and 18S small subunit ribosomal RNA gene (18S rRNA) based PCR in YNRL. Nevertheless, the subtypes of Plasmodium ovale could not be identified based on 18S rRNA gene test, thus posing challenges on its accurate diagnosis. To help establish a more sensitive and specific method for the detection of P. ovale genes, this study performs sequence analysis on k13-propeller polymorphisms in P. ovale.

METHODS

Dried blood spots (DBS) from ovale malaria cases were collected from January 2013 to December 2018, and the infection sources were confirmed according to epidemiological investigation. DNA was extracted, and the coding region (from 206th aa to 725th aa) in k13 gene propeller domain was amplified using nested PCR. Subsequently, the amplified products were sequenced and compared with reference sequence to obtain CDS. The haplotypes and mutation loci of the CDS were analysed, and the spatial structure of the amino acid peptide chain of k13 gene propeller domain was predicted by SWISS-MODEL.

RESULTS

The coding region from 224th aa to 725th aa of k13 gene from P. ovale in 83.3% of collected samples (15/18) were amplified. Three haplotypes were observed in 15 samples, and the values of Ka/Ks, nucleic acid diversity index (π) and expected heterozygosity (He) were 3.784, 0.0095, and 0.4250. Curtisi haplotype, Wallikeri haplotype, and mutant type accounted for 73.3% (11/15), 20.0% (3/15), and 6.7% (1/15). The predominant haplotypes of P. ovale curtisi were determined in all five Myanmar isolates. Of the ten African isolates, six were identified as P. o. curtisi, three were P. o. wallikeri and one was mutant type. Base substitutions between the sequences of P. o. curtisi and P. o. wallikeri were determined at 38 loci, such as c.711. Moreover, the A > T base substitution at c.1428 was a nonsynonymous mutation, resulting in amino acid variation of T476S in the 476th position. Compared with sequence of P. o. wallikeri, the double nonsynonymous mutations of G > A and A > T at the sites of c.1186 and c.1428 leads to the variations of D396N and T476S for the 396th and 476th amino acids positions. For P. o. curtisi and P. o. wallikeri, the peptide chains in the coding region from 224th aa to 725th aa of k13 gene merely formed a monomeric spatial model, whereas the double-variant peptide chains of D396N and T476S formed homodimeric spatial model.

CONCLUSION

The propeller domain of k13 gene in the P. ovale isolates imported into Yunnan Province from Myanmar and Africa showed high differentiation. The sequences of Myanmar-imported isolates belong to P. o. curtisi, while the sequences of African isolates showed the sympatric distribution from P. o. curtisi, P. o. wallikeri and mutant isolates. The CDS with a double base substitution formed a dimeric spatial model to encode the peptide chain, which is completely different from the monomeric spatial structure to encode the peptide chain from P. o. curtisi and P. o. wallikeri.

Malaria Disease and Chemoprophylaxis Usage among Israeli Travelers to Endemic Countries

Prevention of malaria in travelers to endemic countries is one of the complex challenges of travel medicine. Israel has a widespread culture of travel to developing countries, but information regarding malaria prevention is limited so far. Our study, conducted in Sheba Medical Center, Israel, during the years 2008-2018 examined malaria chemoprophylaxis usage and malaria cases in a large group of Israeli travelers returning from endemic countries with any medical complaint. Data were collected regarding travel destinations, conditions, duration of stay, and pretravel consultation. Altogether, 4,708 travelers were included in our study. Travel destinations included Asia (51%), Latin America (31%), and sub-Saharan Africa (SSA) (17%). Median travel duration was 26 days. Only 11.9% reported taking malaria chemoprophylaxis. Of the travelers to SSA, 41.3% took prophylaxis as opposed to only 6% outside of Africa. During the study years, 136 cases of malaria were diagnosed; among them, 82 (60%) were infected with Plasmodium falciparum, of whom all but two were from SSA and none adhered to prophylaxis. Malaria chemoprophylaxis usage was found to be negligible in travel to many countries still considered endemic. Higher prophylaxis usage was found among travelers to SSA, but numbers are still lower than recommended. The low number of malaria cases seen in destinations outside SSA, as documented in our cohort, is likely to represent travel to low risk areas and not high prophylaxis usage. We urge re-evaluation of current CDC and Israeli guidelines which still recommend using chemoprophylaxis in many low-risk countries, as focus on high-risk countries may increase adherence.

Management of Travel-Related Infectious Diseases in the Emergency Department

Purpose of Review

Emergency physicians generally have limited exposure to internationally acquired illnesses. However, travelers can present quite ill, and delays in recognition and treatment can lead to increased morbidity and mortality. This paper aims to summarize typical presentations of common international diseases and provide the emergency physician with a practical approach based on current guidelines.

Recent Findings

In the treatment of traveler’s diarrhea, azithromycin has become the treatment of choice due to the growing antibiotic resistance. Intravenous artesunate was approved in 2019 under investigational new drug protocol for the treatment of severe malaria, and artemisinin-based combination therapies (ACTs) have become the first-line treatment for most cases of uncomplicated malaria. Since the 2015 outbreak, Zika has become a concern to many travelers, but the current treatment is supportive.

Summary

Clinicians should be aware of a few noteworthy updates in the treatment of internationally acquired illnesses, but more importantly, they must recognize warning signs of severe illness and treat promptly. Future research on workup and disposition could help emergency physicians identify which patients need admission in well-appearing febrile travelers.

Targeted deep amplicon sequencing of kelch 13 and cytochrome b in Plasmodium falciparum isolates from an endemic African country using the Malaria Resistance Surveillance (MaRS) protocol

Background

Routine molecular surveillance for imported drug-resistant malaria parasites to the USA and European Union is an important public health activity. The obtained molecular data are used to help keep chemoprophylaxis and treatment guidelines up to date for persons traveling to malaria endemic countries. Recent advances in next-generation sequencing (NGS) technologies provide a new and effective way of tracking malaria drug-resistant parasites.

Methods

As part of a technology transfer arrangement between the CDC Malaria Branch and the Istituto Superiore di Sanità (ISS), Rome, Italy, the recently described Malaria Resistance Surveillance (MaRS) protocol was used to genotype 148 Plasmodium falciparum isolates from Eritrea for kelch 13 (k13) and cytochrome b (cytb) genes, molecular markers associated with resistance to artemisinin (ART) and atovaquone/proguanil (AP), respectively.

Results

Spanning the full-length k13 gene, seven non-synonymous single nucleotide polymorphisms (SNPs) were found (K189N, K189T, E208K, D281V, E401Q, R622I and T535M), of which none have been associated with artemisinin resistance. No mutations were found in cytochrome b.

Conclusion

All patients successfully genotyped carried parasites susceptible to ART and AP treatment. Future studies between CDC Malaria Branch and ISS are planned to expand the MaRS system, including data sharing, in an effort to maintain up to date treatment guidelines for travelers to malaria endemic countries.

Barriers to malaria prevention among immigrant travelers in the United States who visit friends and relatives in sub-Saharan Africa: A cross-sectional, multi-setting survey of knowledge, attitudes, and practices

BACKGROUND

Despite achievements in the reduction of malaria globally, imported malaria cases to the United States by returning international travelers continue to increase. Immigrants to the United States from sub-Saharan Africa (SSA) who then travel back to their homelands to visit friends and relatives (VFRs) experience a disproportionate burden of malaria illness. Various studies have explored barriers to malaria prevention among VFRs and non-VFRs-travelers to the same destinations with other purpose for travel-but few employed robust epidemiologic study designs or performed comparative analyses of these two groups. To better quantify the key barriers that VFRs face to implement effective malaria prevention measures, we conducted a comprehensive community-based, cross-sectional, survey to identify differences in malaria prevention knowledge, attitudes, and practices (KAP) among VFRs and others traveling to Africa and describe the differences between VFRs and other types of international travelers.

METHODS AND FINDINGS

Three distinct populations of travelers with past or planned travel to malaria-endemic countries of SSA were surveyed: VFRs diagnosed with malaria as reported through a state health department; members of the general VFR population (community); and VFR and non-VFR travelers presenting to a travel health clinic, both before their pretravel consultation and again, after return from travel. A Community Advisory Board of African immigrants and prior qualitative research informed survey development and dissemination. Across the three groups, 489 travelers completed surveys: 351 VFRs and 138 non-VFRs. VFRs who reported taking antimalarials on their last trip rated their concern about malaria higher than those who did not. Having taken five or more trips to SSA was reported more commonly among VFRs diagnosed with malaria than community VFRs (44.0% versus 20.4%; p = 0.008). Among travel health clinic patients surveyed before and after travel, VFR travelers were less successful than non-VFRs in adhering to their planned use of antimalarials (82.2% versus 98.7%; p = 0.001) and employing mosquito bite avoidance techniques (e.g., using bed nets: 56.8% versus 81.8%; p = 0.009). VFRs who visited the travel health clinic were more likely than VFR respondents from the community to report taking an antimalarial (83.0% versus 61.9%; p = 0.009), or to report bite avoidance behaviors (e.g., staying indoors when mosquitoes were out: 80.9% versus 59.5%; p = 0.009).

CONCLUSIONS

We observed heterogeneity in malaria prevention behaviors among VFRs and between VFR and non-VFR traveler populations. Although VFRs attending the travel health clinic appear to demonstrate better adherence to malaria prevention measures than VFR counterparts surveyed in the community, specialized pretravel care is not sufficient to ensure chemoprophylaxis use and bite avoidance behaviors among VFRs. Even when seeking specialized pretravel care, VFRs experience greater barriers to the use of malaria prevention than non-VFRs. Addressing access to health care and upstream barrier reduction strategies that make intended prevention more achievable, affordable, easier, and resonant among VFRs may improve malaria prevention intervention effectiveness.

Imported Malaria in Countries where Malaria Is Not Endemic: a Comparison of Semi-immune and Nonimmune Travelers

The continuous increase in long-distance travel and recent large migratory movements have changed the epidemiological characteristics of imported malaria in countries where malaria is not endemic (here termed non-malaria-endemic countries). While malaria was primarily imported to nonendemic countries by returning travelers, the proportion of immigrants from malaria-endemic regions and travelers visiting friends and relatives (VFRs) in malaria-endemic countries has continued to increase. VFRs and immigrants from malaria-endemic countries now make up the majority of malaria patients in many nonendemic countries. Importantly, this group is characterized by various degrees of semi-immunity to malaria, resulting from repeated exposure to infection and a gradual decline of protection as a result of prolonged residence in non-malaria-endemic regions. Most studies indicate an effect of naturally acquired immunity in VFRs, leading to differences in the parasitological features, clinical manifestation, and odds for severe malaria and clinical complications between immune VFRs and nonimmune returning travelers. There are no valid data indicating evidence for differing algorithms for chemoprophylaxis or antimalarial treatment in semi-immune versus nonimmune malaria patients. So far, no robust biomarkers exist that properly reflect anti-parasite or clinical immunity. Until they are found, researchers should rigorously stratify their study results using surrogate markers, such as duration of time spent outside a malaria-endemic country.

Adherence to recommendations at a Canadian tertiary care Family Travel Clinic - A single centre analysis

BACKGROUND

Infectious and non-infectious risks associated with international travel can be reduced with adherence to pre-travel advice from practitioners trained in travel medicine.

METHODS

A prospective cohort study was conducted in a tertiary care children's hospital to assess adherence to malaria chemoprophylaxis, safe water and food consumption, mosquito bite protection, motor vehicle safety and travel vaccines using structured questionnaires. High risk groups assessed included child travelers and those visiting friends and relatives (VFRs).

RESULTS

In total, 290 participants (133 children and 157 adults) were enrolled and completed at least one study questionnaire. In general, with the exception of vaccines, adherence to recommendations was sub-optimal. Among children and adults, adherence to malaria prophylaxis recommendations was lower in VFRs than in non-VFRs. The proportion of children VFRs (cVFRs) and adult VFRs (aVFRs) who adhered to the following recommendations were malaria chemoprophylaxis (47%, 33%), safe water (71%, 74%) and food recommendations (18%, 6%), insect bite avoidance (21%, 12%), and motor vehicle safety (13%, 11%) respectively. Adherence to recommended vaccines uptake was greater than 90% in all groups.

CONCLUSION

With the exception of vaccine uptake, sub-optimal adherence levels to travel recommendations was identified in all groups, and in particular VFRs, highlighting the need for proactive discussions around barriers to adherence.

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

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

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.

Guidance for Using Tafenoquine for Prevention and Antirelapse Therapy for Malaria - United States, 2019

An estimated 219 million cases of malaria occurred worldwide in 2017, causing approximately 435,000 deaths (1). Malaria is caused by intraerythrocytic protozoa of the genus Plasmodium transmitted to humans through the bite of an infective Anopheles mosquito. Five Plasmodium species that regularly cause illness in humans are P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi (2). The parasite first develops in the liver before infecting red blood cells. Travelers to areas with endemic malaria can prevent malaria by taking chemoprophylaxis. However, most antimalarials do not kill the liver stages of the parasite, including hypnozoites that cause relapses of disease caused by P. vivax or P. ovale. Therefore, patients with these relapsing species must be treated with two medications: one for the acute infection, and another to treat the hypnozoites (antirelapse therapy). Until recently, primaquine was the only drug available worldwide to kill hypnozoites. Tafenoquine, a long-acting 8-aminoquinoline drug related to primaquine, was approved by the Food and Drug Administration (FDA) on July 20, 2018, for antirelapse therapy (Krintafel) and August 8, 2018, for chemoprophylaxis (Arakoda) (3,4). This report reviews evidence for the efficacy and safety of tafenoquine and provides CDC guidance for clinicians who prescribe chemoprophylaxis for travelers to areas with endemic malaria and treat malaria.

Utility of 8-Aminoquinolines in Malaria Prophylaxis in Travelers

PURPOSE OF REVIEW

To review the current status of 8-aminoquinolines in the prophylaxis of malaria among travelers, in light of the recent approval of tafenoquine.

RECENT FINDINGS

Primaquine continues to provide excellent primary prophylaxis against all Plasmodium species. Tafenoquine provides similarly good prophylaxis, with the benefit of weekly dosing. Both agents require glucose-6-phosphate dehydrogenase activity testing before use and are contraindicated in pregnancy. Pharmacodynamic variability relating to CYP2D6 may underlie some cases of primaquine failure; the effects of CYP2D6 on tafenoquine efficacy require further study. Tafenoquine and primaquine are the only current drugs that provide complete malaria prophylaxis, and should be considered the agents of choice in areas where both P. vivax and falciparum are frequent. Monthly tafenoquine is promising and should be further studied in travelers.

Physical rehabilitation therapists' perspective of the opioid crisis with evidence-based recommendations

In 2017, the Secretary of Health and Human Services and Office of the Surgeon General declared the opioid crisis of our nation to be a public health emergency. In response to the Office of the Assistant Secretary of Health and Office of the Surgeon General's 'Call to Action', the Therapist category of the US Public Health Service commissioned a nine-member task force consisting of pain science subject matter experts to study the Therapists' role in effectively reducing chronic pain and opioid abuse. This article addresses the opioid epidemic, how patients with chronic pain have been managed inappropriately, and five key, evidence-based recommendations from this task force.