First molecular documented case of a rarely reported parasite: Plasmodium knowlesi infection in Denmark in a traveller returning from Malaysian Borneo.

Plasmodium knowlesi has been reported as an emerging infection throughout the Southeast Asian region, especially in the Malaysian state of Sabah, where it accounts for the majority of the malaria cases reported. This is in contrast to Europe, where imported P. knowlesi is a rarely reported infection. We present a case of P. knowlesi infection in a Danish woman returning from a short trip to Malaysian Borneo. Microscopy of blood smears revealed 0.8% infected erythrocytes, but due to the atypical morphological presentation, a conclusive species identification was made by molecular methods. Plasmodium knowlesi is a potentially fatal infection and taking the increasing travel activity into consideration after the coronavirus disease 2019 (COVID-19) pandemic, P. knowlesi should be a differential diagnosis in patients with travel-associated illness returning from highly endemic Southeast Asian areas.

Determinants of malaria infections among children in refugee settlements in Uganda during 2018-2019.

BACKGROUND: While 5% of 247 million global malaria cases are reported in Uganda, it is also a top refugee hosting country in Africa, with over 1.36 million refugees. Despite malaria being an emerging challenge for humanitarian response in refugee settlements, little is known about its risk factors. This study aimed to investigate the risk factors for malaria infections among children under 5 years of age in refugee settlements in Uganda. METHODS: We utilized data from Uganda's Malaria Indicator Survey which was conducted between December 2018 and February 2019 at the peak of malaria season. In this national survey, household level information was obtained using standardized questionnaires and a total of 7787 children under 5 years of age were tested for malaria using mainly the rapid diagnostic test. We focused on 675 malaria tested children under five in refugee settlements located in Yumbe, Arua, Adjumani, Moyo, Lamwo, Kiryadongo, Kyegegwa, Kamwenge and Isingiro districts. The extracted variables included prevalence of malaria, demographic, social-economic and environmental information. Multivariable logistic regression was used to identify and define the malaria associated risk factors. RESULTS: Overall, malaria prevalence in all refugee settlements across the nine hosting districts was 36.6%. Malaria infections were higher in refugee settlements located in Isingiro (98.7%), Kyegegwa (58.6%) and Arua (57.4%) districts. Several risk factors were significantly associated with acquisition of malaria including fetching water from open water sources [adjusted odds ratio (aOR) = 1.22, 95% CI: 0.08-0.59, P = 0.002], boreholes (aOR = 2.11, 95% CI: 0.91-4.89, P = 0.018) and water tanks (aOR = 4.47, 95% CI: 1.67-11.9, P = 0.002). Other factors included pit-latrines (aOR = 1.48, 95% CI: 1.03-2.13, P = 0.033), open defecation (aOR = 3.29, 95% CI: 1.54-7.05, P = 0.002), lack of insecticide treated bed nets (aOR = 1.15, 95% CI: 0.43-3.13, P = 0.003) and knowledge on the causes of malaria (aOR = 1.09, 95% CI: 0.79-1.51, P = 0.005). CONCLUSIONS: The persistence of the malaria infections were mainly due to open water sources, poor hygiene, and lack of preventive measures that enhanced mosquito survival and infection. Malaria elimination in refugee settlements requires an integrated control approach that combines environmental management with other complementary measures like insecticide treated bed nets, indoor residual spraying and awareness.

Two cases of COVID-19 presenting with severe malaria: a clinical challenge (case report).

The novel coronavirus (COVID-19) pandemic has stretched the medical resources of both developed and developing countries. The global focus on COVID-19 may lead to the neglect of other infectious diseases such as malaria which is still endemic in many African countries. Some similarities in malaria and COVID-19 disease presentations may also lead to late diagnosis of either disease which could complicate the effects. Here, we present two cases of a 6-year-old child and a 17-year-old female who presented to a primary care facility in Ghana with a clinical and microscopy-confirmed diagnosis of severe malaria complicated by thrombocytopenia. As their symptoms worsened with associated respiratory complications, nasopharyngeal samples were taken for real-time polymerase chain reaction (RT-PCR) and tested positive for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Clinicians, policymakers, and public health practitioners should be alert to the variety of presenting symptoms of COVID-19 and its similarity to malaria to mitigate the risk of mortality from either disease.

Universal two-dimensional labelled probe-mediated melting curve analysis based on multiplex PCR for rapid typing of Plasmodium in a single closed tube.

Currently, malaria is still one of the major public health problems commonly caused by the four Plasmodium species. The similar symptoms of malaria and the COVID-19 epidemic of fever or fatigue lead to frequent misdiagnosis. The disadvantages of existing detection methods, such as time-consuming, costly, complicated operation, need for experienced technicians, and indistinguishable typing, lead to difficulties in meeting the clinical requirements of rapid, easy, and accurate typing of common Plasmodium species. In this study, we developed and optimized a universal two-dimensional labelled probe-mediated melting curve analysis (UP-MCA) assay based on multiplex and asymmetric PCR for rapid and accurate typing of five Plasmodium species, including novel human Plasmodium, Plasmodium knowlesi (Pk), in a single closed tube following genome extraction. The assay showed a limit of detection (LOD) of 10 copies per reaction and could accurately distinguish Plasmodium species from intra-plasmodium and other pathogens. Additionally, we proposed and validated different methods of fluorescence quenching and tag design for probes that are suitable for UP-MCA assays. Moreover, the clinical performance of the Plasmodium UP-MCA assay using a base-quenched universal probe was evaluated using 226 samples and showed a sensitivity of 100% (164/164) and specificity of 100% (62/62) at a 99% confidence interval, with the microscopy method as the gold standard. In summary, the UP-MCA assay showed excellent sensitivity, specificity, and accuracy for genotyping Plasmodium species spp. Additionally, it facilitates convenient and rapid Plasmodium detection in routine clinical practice and has great potential for clinical translation.

Management of imported malaria in the emergency department: Adequacy compared to guidelines, and impact of the SARS-CoV-2 pandemic.

OBJECTIVES: Adequacy of imported malaria management with respect to guidelines in emergency departments (ED) is low. We aimed to identify factors associated with this non-compliance, and a potential impact of the SARS-CoV-2 pandemic. PATIENTS AND METHODS: Patients presenting with imported malaria at the ED of the hospital of Melun (France), from January 1, 2017 to February 14, 2022 were retrospectively included. RESULTS: Among 205 adults and 25 children, biological criteria of severity were fully assessed in 10% of cases; lactates (40%) and blood pH (21%) levels were the main missing variables. Of 74 patients (32%) with severe malaria, 13 were misclassified as uncomplicated malaria. The choice and dosage of treatment were adequate in 85% and 92% of cases, respectively. Treatment conformity was lower in severe malaria cases than in non-severe malaria cases (OR 0.15 [95% CI 0.07-0.31]), with oral treatment in 17 patients with severe malaria; conformity was higher in the intensive care unit (OR 4.10 [95% CI 1.21-13.95]). Patients with severe malaria were more likely to start treatment within 6hours than patients with uncomplicated malaria (OR 1.97 [95% CI 1.08-3.43]), as were patients infected by P.falciparum compared to other species (OR 4.63 [95% CI 1.03-20.90]). Consulting during the SARS-CoV-2 pandemic was the only organizational factor associated with a lower probability of adequate management (OR 0.42 [95% CI 0.23-0.75]). CONCLUSION: Initial evaluation of malaria severity and time to treatment administration could be improved. These have been adversely impacted by the SARS-CoV-2 pandemic.

Return to Travel in the Coronavirus Disease 2019 Pandemic Recovery Period and Implications for Imported Malaria: Reinforcing Prevention, Early Diagnosis, and Appropriate Treatment of Malaria.

Return to international travel in the COVID-19 pandemic recovery period is expected to increase the number of patients with imported malaria in the United States (US). Malaria prevention in travelers and preparedness for timely diagnosis and appropriate treatment are key to minimize imported malaria morbidity and mortality. Intravenous artesunate (IVAS) is now available from commercial distributors in the US for the treatment of severe malaria. Hospitals and pharmacists should have a plan for malaria treatment, including stocking artemether-lumefantrine for uncomplicated malaria, and stocking or planning for rapid procurement of IVAS for the treatment of severe malaria.

Malaria diagnostic methods with the elimination goal in view.

Malaria control measures have been in use for years but have not completely curbed the spread of infection. Ultimately, global elimination is the goal. A major playmaker in the various approaches to reaching the goal is the issue of proper diagnosis. Various diagnostic techniques were adopted in different regions and geographical locations over the decades, and these have invariably produced diverse outcomes. In this review, we looked at the various approaches used in malaria diagnostics with a focus on methods favorably used during pre-elimination and elimination phases as well as in endemic regions. Microscopy, rapid diagnostic testing (RDT), loop-mediated isothermal amplification (LAMP), and polymerase chain reaction (PCR) are common methods applied depending on prevailing factors, each with its strengths and limitations. As the drive toward the elimination goal intensifies, the search for ideal, simple, fast, and reliable point-of-care diagnostic tools is needed more than ever before to be used in conjunction with a functional surveillance system supported by the ideal vaccine.

Using social media for health education and promotion: a pilot of WeChat-based prize quizzes on China national malaria day.

BACKGROUND: Imported malaria cases remains a key health concern, especially during the COVID-19 pandemic. Providing accurate health information is important to improving people's awareness of malaria. WeChat is an excellent social media tool for health information dissemination, especially during the pandemic. This study explored the effect of malaria knowledge dissemination via a WeChat public account. METHODS: A questionnaire for data collection was constructed using the online survey tool Sojump. Questionnaires were sent to users who followed the Jiangsu institute of Parasitic Disease WeChat public account during the National Malaria Day 2021 period. A small incentive (WeChat Red Packet) was distributed to everyone who answered the questionnaire correctly on time. RESULTS: A total of 13,169 valid questionnaires were collected during the China National Malaria Day period. Questions in which participants focused mainly on information pertaining to themselves, such as infection, symptoms, and epidemic areas, reached highest accuracy (above 90%). Questionnaires were submitted through smartphones and most of them were completed during the period of 4 days from April 23 to April 26, 2021 when a WeChat Red Packet was offered. The accuracy of responses was related to bolded words and location and number of knowledge points that were shown at the beginning of the questionnaire. The number of users of the WeChat public account in question increased from 5961 to 12,339 in just 4 days of the activity. CONCLUSION: A WeChat public account is a convenient and accessible tool for spreading malaria-related health information to the public. Distribution of incentives (Red Packets) can effectively increase public attention to popular science and health information and activities.

Epidémiology of malaria from 2019 to 2021 in the southeastern city of Franceville, Gabon.

BACKGROUND: In Gabon, a new national malaria control policy was implemented in 2003. It resulted in a decrease in the number of malaria cases in the country. In March 2020, the disruption of routine health services due to the COVID-19 pandemic has led to an increase in cases and deaths due to malaria. However, in Franceville, south-east Gabon, no data on malaria cases recorded before, during and after the COVID-19 epidemic has been published. Thus, the objective of this study was to determine the epidemiological characteristics of malaria in Franceville from 2019 to 2021. METHODS: A retrospectively study of malaria cases was performed at the Hôpital de l'Amitié Sino-Gabonaise (HASG). Information regarding age, gender, malaria diagnosis by microscopy and hematology cell count were collected from laboratory registers from June 2019 to December 2021. Malaria data were analyzed and correlated with seasonal variations. RESULTS: The data of 12,695 febrile patients were collected from the laboratory registers of the HASG, among which 4252 (33.5%) patients were found positive for malaria. The malaria prevalence was 37.5% in 2020 year. This prevalence was highest compared to the 2019 (29.6%) and 2021 (31.5%) year (p < 0.001). During the short rainy season (October to December), a large increase in malaria cases was observed all three year, from 2019 to 2021 (p > 0.05). CONCLUSION: The prevalence of malaria in Franceville was very high during COVID-19 pandemic. It is therefore necessary to strengthen existing interventions and implement more effective interventions.

Impact of school-based malaria intervention on primary school teachers' time in Malawi: evidence from a time and motion study.

BACKGROUND: School-based health (SBH) programmes that are contingent on primary school teachers are options to increase access to malaria treatment among learners. However, perceptions that provision of healthcare by teachers may be detrimental to teaching activities can undermine efforts to scale up school-based malaria control. The objective of this study was to assess the impact of school-based malaria diagnosis and treatment using the Learner Treatment Kit (LTK) on teachers' time. METHODS: A time and motion study was conducted in 10 primary schools in rural Malawi. Teachers who had been trained to diagnose and treat uncomplicated malaria were continuously observed in real time during school sessions and the time they spent on all activities were recorded by independent observers before and after LTK implementation. A structured form, programmed digitally, was used for data collection. Paired sample t-tests were used to assess pre-post differences in average hours teachers spent on the following key activities: direct teaching; indirect teaching; administration; LTK and non-teaching tasks. Multivariable repeated measures mixed regression models were used to ascertain impact of LTK on average durations teachers spent on the key activities. RESULTS: Seventy-four teachers, trained to use LTK, were observed. Their mean age and years of teaching experience were 34.7 and 8.7, respectively. Overall, 739.8 h of teacher observations took place. The average time teachers spent in school before relative to after LTK was 5.8 vs. 4.8 h, p = 0.01. The cumulative percentage of time teachers spent on core teaching activities (teaching and administration) was approximately 76% and did not change substantially before and after LTK. Some 24.3% of teachers' time is spent on non-teaching activities. On average, teachers spent 2.9% of their time providing LTK services daily. Per day, each teacher spent less time on administrative (0.74 vs. 1.07 h, p = 0.02) and non-teaching activities (0.96 vs. 1.41 h, p = 0.01) during LTK compared with the period before LTK. CONCLUSION: School-based health (SBH) programmes are not detrimental to teaching activities. Teachers manage their time to ensure additional time required for SBH services is not at the expense of teaching duties. Programming and policy implications of tasking teachers with SBH does not have substantial opportunity costs. Teachers should continue delivering SBH programmes to promote learners' health.

The impact of COVID-19 on implementation of mass testing, treatment and tracking of malaria in rural communities in Ghana: A qualitative study.

BACKGROUND: Mass test, treat and track (MTTT) of malaria is ongoing in the Pakro sub district of Ghana. In the delivery of MTTT of malaria, community health volunteers are trained to routinely provide this service through a door-to-door strategy. Following the report of the first cases of COVID-19 in Ghana, we conducted this study to explore the effects of the pandemic on the implementation of the MTTT of malaria intervention. METHODS: Using qualitative methodology, we conducted ten focus groups discussions (FGDs) in eight communities: eight with community members (N = 49); one with health workers (N = 6), and one with MTTT of malaria volunteers. In addition, two in-depth interviews (IDI) were conducted, one with health worker and another with a health manager. All interviews were recorded, translated into English during transcription and analysed using QSR NVivo 12. Thematic content analysis was used in this study. RESULTS: The findings of the study showed an increase in the number of people reporting with complications of malaria in health facilities in the study communities during the COVID-19 period. Some participants were of the view that COVID-19 rumours and misinformation could largely be responsible for the low coverage and uptake of the MTTT of malaria intervention. To sustain the uptake of the MTTT intervention, community engagement strategies were employed to identify and respond to these rumours. Also, incentive schemes were introduced to encourage parents and children to participate in the MTTT intervention during this period of COVID-19. CONCLUSION: Findings suggest that the COVID-19 pandemic has adversely affected the provision and uptake of malaria prevention and treatment services, especially the MTTT of malaria being implemented at the community level. These observations underscore the need to find innovative ways to address the challenges encountered in providing essential services during public health emergencies.

Prevalence of Malaria and Covid-19 in Febrile Patients in Lomé, Togo in 2020.

PURPOSE: The objective of this study was to estimate the prevalence of malaria and Covid-19 by PCR and serological tests in febrile patients in Lomé. METHODS: A cross-sectional study was conducted from September 1 to October 31, 2020 in febrile patients ≥ 10 years in three health facilities in Lomé. Finger stick blood was collected to detect Plasmodium spp. using thin/thick smear and venous blood on EDTA tubes to test for malaria Histidin-Rich-Protein-2 antigen using rapid diagnostic tests (RDT) and SARS-CoV-2 antibodies specific immunoglobulin (Ig) M and G. Detection of SARS-CoV-2 in nasopharyngeal samples was performed by rRT-PCR using GeneXpert. RESULTS: A total of 243 participants (61.7% of female) with median age 28 years (IQR 18-41) were included in the study. Prevalence of malaria was 25.1%, 95% CI [19.8-31.0] and 30.4%, 95% CI [24.7-36.7] for thin/thick smear and rapid malaria test, respectively. Eighteen patients (7.4%, 95% CI [4.4-11.5]) were positive for SARS-CoV-2 and forty-two (17.3%, 95% CI [12.8-22.6]) were positive for IgM and/or IgG against SARS-CoV-2. SARS-CoV-2 IgM seroprevalence was significantly higher in malaria RDT positive participants (33.8% vs. 10.1%, p < 0.001). CONCLUSION: This study confirms a possible cross-reactivity between Covid-19 and malaria in case of single use of rapid tests, suggesting a possible past contamination. In case of clinical signs related to Covid-19 in malaria-endemic areas, PCR screening should be requested in order to identify and isolate patients.

Automated Recognition of Plasmodium falciparum Parasites from Portable Blood Levitation Imaging.

In many malaria-endemic regions, current detection tools are inadequate in diagnostic accuracy and accessibility. To meet the need for direct, phenotypic, and automated malaria parasite detection in field settings, a portable platform to process, image, and analyze whole blood to detect Plasmodium falciparum parasites, is developed. The liberated parasites from lysed red blood cells suspended in a magnetic field are accurately detected using this cellphone-interfaced, battery-operated imaging platform. A validation study is conducted at Ugandan clinics, processing 45 malaria-negative and 36 malaria-positive clinical samples without external infrastructure. Texture and morphology features are extracted from the sample images, and a random forest classifier is trained to assess infection status, achieving 100% sensitivity and 91% specificity against gold-standard measurements (microscopy and polymerase chain reaction), and limit of detection of 31 parasites per µL. This rapid and user-friendly platform enables portable parasite detection and can support malaria diagnostics, surveillance, and research in resource-constrained environments.

The striking mimics between COVID-19 and malaria: A review.

Objectives: COVID-19 is a transmissible illness triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since its onset in late 2019 in Wuhan city of China, it continues to spread universally, leading to an ongoing pandemic that shattered all efforts to restrain it. On the other hand, in Africa, the COVID-19 infection may be influenced by malaria coinfection. Hence, in this review article, we aimed to give a comprehensive account of the similarities between COVID-19 and malaria in terms of symptoms, clinical, immunological, and molecular perspectives. Methodology: In this article, we reviewed over 50 research papers to highlight the multilayered similarities between COVID-19 and malaria infections that might influence the ontology of COVID-19. Results: Despite the poor health and fragile medical system of many sub-Saharan African countries, they persisted with a statistically significantly low number of COVID-19 cases. This was attributed to many factors such as the young population age, the warm weather, the lack of proper diagnosis, previous infection with malaria, the use of antimalarial drugs, etc. Additionally, population genetics appears to play a significant role in shaping the COVID-19 dynamics. This is evident as recent genomic screening analyses of the angiotensin-converting enzyme 2 (ACE2) and malaria-associated-variants identified 6 candidate genes that might play a role in malaria and COVID-19 incidence and severity. Moreover, the clinical and pathological resemblances between the two diseases have made considerable confusion in the diagnosis and thereafter curb the disease in Africa. Therefore, possible similarities between the diseases in regards to the clinical, pathological, immunological, and genetical ascription were discussed. Conclusion: Understanding the dynamics of COVID-19 infection in Sub-Saharan Africa and how it is shaped by another endemic disease like malaria can provide insights into how to tailor a successful diagnostic, intervention, and control plans that lower both disease morbidity and mortality.

MIS-C and co-infection with P. vivax and P. falciparum in a child: a clinical conundrum.

BACKGROUND: The ongoing Coronavirus Disease 2019 (COVID-19) epidemic represents an unprecedented global health challenge. Many COVID-19 symptoms are similar to symptoms that can occur in other infections. Malaria should always be considered in patients with SARS-CoV-2 infection returning from endemic areas. CASE PRESENTATION: We present the first case of multisystem inflammatory syndrome (MIS-C) and Plasmodium vivax-falciparum and SARS-CoV2 coinfection in children. Despite clearance of parassitaemia and a negative COVID-19 nasopharyngeal PCR, the patient's clinical conditions worsened. The World Health Organization (WHO) criteria were used to make the diagnosis of MIS-C. Treatment with intravenous immunoglobulins and methylprednisolone was effective. CONCLUSIONS: This case emphasizes the importance of considering malaria diagnosis in patients returning from endemic areas, even in the COVID 19 era. Malaria and SARS-CoV2 co-infection may increase the risk of MIS-C, for which early detection is critical for proper management.

Lessons for improved COVID-19 surveillance from the scale-up of malaria testing strategies.

Effective control of infectious diseases is facilitated by informed decisions that require accurate and timely diagnosis of disease. For malaria, improved access to malaria diagnostics has revolutionized malaria control and elimination programmes. However, for COVID-19, diagnosis currently remains largely centralized and puts many low- and middle-income countries (LMICs) at a disadvantage. Malaria and COVID-19 are infectious diseases that share overlapping symptoms. While the strategic responses to disease control for malaria and COVID-19 are dependent on the disease ecologies of each disease, the fundamental need for accurate and timely testing remains paramount to inform accurate responses. This review highlights how the roll-out of rapid diagnostic tests has been fundamental in the fight against malaria, primarily within the Asia Pacific and along the Greater Mekong Subregion. By learning from the successful elements of malaria control programmes, it is clear that improving access to point-of-care testing strategies for COVID-19 will provide a suitable framework for COVID-19 diagnosis in not only the Asia Pacific, but all malarious countries. In malaria-endemic countries, an integrated approach to point-of-care testing for COVID-19 and malaria would provide bi-directional benefits for COVID-19 and malaria control, particularly due to their paralleled likeness of symptoms, infection control strategies and at-risk individuals. This is especially important, as previous disease pandemics have disrupted malaria control infrastructure, resulting in malaria re-emergence and halting elimination progress. Understanding and combining strategies may help to both limit disruptions to malaria control and support COVID-19 control.

Prolonged fever and exaggerated hypercoagulopathy in malaria vivax relapse and COVID-19 co-infection: a case report.

BACKGROUND: Coronavirus disease 2019 (COVID-19) often causes atypical clinical manifestations similar to other infectious diseases. In malaria-endemic areas, the pandemic situation will very likely result in co-infection of COVID-19 and malaria, although reports to date are still few. Meanwhile, this disease will be challenging to diagnose in areas with low malaria prevalence because the symptoms closely resemble COVID-19. CASE PRESENTATION: A 23-year-old male patient presented to the hospital with fever, anosmia, headache, and nausea 1 week before. He was diagnosed with COVID-19 and treated for approximately 10 days, then discharged to continue self-quarantine at home. 2 weeks later, he returned to the hospital with a fever raised intermittently every 2 days and marked by a chilling-fever-sweating cycle. A laboratory test for malaria and a nasopharyngeal swab for SARS CoV-2 PCR were conducted, confirming both diagnoses. The laboratory examination showed markedly elevated D-dimer. He was treated with dihydroartemisinin-piperaquine (DHP) 4 tablets per day for 3 days and primaquine 2 tablets per day for 14 days according to Indonesian National Anti-malarial Treatment Guidelines. After 6 days of treatment, the patient had no complaints, and the results of laboratory tests had improved. This report describes the key points in considering the differential diagnosis and prompt treatment of malaria infection during the pandemic of COVID-19 in an endemic country to prevent the worse clinical outcomes. COVID-19 and malaria may also cause a hypercoagulable state, so a co-infection of those diseases may impact the prognosis of the disease. CONCLUSION: This case report shows that considering the possibility of a co-infection in a COVID-19 patient who presents with fever can prevent delayed treatment that can worsen the disease outcome. Paying more attention to a history of travel to malaria-endemic areas, a history of previous malaria infection, and exploring anamnesis regarding the fever patterns in patients are important points in making a differential diagnosis of malaria infection during the COVID-19 pandemic.

[Epidemiological characteristics of imported malaria in Zhengzhou City from 2016 to 2020].

OBJECTIVE: To analyze the epidemiological characteristics of reported imported malaria cases in Zhengzhou City from 2016 to 2020, so as to provide insights into the management of imported malaria in the city. METHODS: All data pertaining to cases with definitive diagnosis of malaria in Zhengzhou City from 2016 to 2020 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China, including individual demographic data, and malaria onset, initial diagnosis and definitive diagnosis data. All data were descriptively analyzed. The duration from malaria onset to initial diagnosis, from initial diagnosis to definitive diagnosis and from onset to definitive diagnosis was compared among cases. In addition, the diagnoses of imported malaria cases in which definitive diagnosis was made were compared with the reexaminations by Zhengzhou Municipal Malaria Diagnosis Reference Laboratory. RESULTS: A total of 302 cases with definitive diagnosis of malaria were reported in Zhengzhou City from 2016 to 2020, and all were imported cases, with Plasmodium falciparum malaria as the predominant type (230 cases, 76.2%). There were 293 malaria cases imported from Africa (293 cases, 97.0%), which mainly included Nigeria (48 cases, 15.9%), Angola (40 cases, 13.2%), and the Democratic Republic of the Congo (29 cases, 9.6%). There was no obvious seasonality found in the date of malaria onset and time of reporting malaria. The ratio of male to female malaria cases was 49.3:1, and there were 103 cases (34.1%) with the current residency address in Zhengzhou City, 193 cases (63.9%) with the current residency address in other cities of Henan Province and 6 cases (2.0%) in other provinces of China. There were 271 cases (89.7%) seeking initial diagnosis in medical institutions, and the diagnostic accuracy of malaria was 56.6% (171/302) at initial diagnosis institutions. A total of 122 cases (40.4%) sought medical care on the day of malaria onset, and 252 cases (86.4%) within 3 days; however, only 22 cases (7.3%) were definitively diagnosed on the day of onset, and 162 cases (53.6%) diagnosed within 3 days. There were no significant differences between malaria cases seeking initial diagnosis at medical institutions and disease control and prevention institutions in terms of the duration from malaria onset to initial diagnosis (Z = -1.663, P > 0.05), from initial diagnosis to definitive diagnosis (Z = -0.413, P > 0.05) or from malaria onset to definitive diagnosis (Z = -0.838, P > 0.05). The median duration (interquartile range) from initial diagnosis to definitive diagnosis of malaria was 3.00 (2.00), 3.00 (6.00), 2.00 (4.00) d and 1.00 (1.00) d among cases seeking medical care at township-level and lower, county-, city- and province-level medical institutions, and the median duration from initial diagnosis to definitive diagnosis of malaria was significantly longer among cases seeking medical care at township-level and lower medical institutions than at city (Z = -3.286, P < 0.008 33) and province-level medical institutions (Z = -9.119, P < 0.008 33), while the median duration from initial diagnosis to definitive diagnosis [1.00 (3.00) d vs. 2.00 (4.00) d; Z = -4.099, P < 0.016] and from malaria onset to definitive diagnosis [3.00 (4.00) d vs. 4.00 (5.00) d; Z = -2.868, P < 0.016] among malaria cases with the current residency address in Zhengzhou City was both shorter than in other cities of Henan Province. The diagnostic accuracy was 89.1% (269/302) among malaria cases in which definitive diagnosis was made, and the accuracy of malaria reexaminations was 94.0% (284/302) in Zhengzhou Municipal Malaria Diagnosis Reference Laboratory. CONCLUSIONS: P. falciparum malaria was predominant among reported imported malaria cases in Zhengzhou City from 2016 to 2020, and these imported malaria cases were predominantly diagnosed at medical institutions; however, the diagnostic capability of malaria is poor in township-level and lower medical institutions. Strengthening the collaboration between medical institutions and disease control and prevention institutions and improving the diagnostic capability building at medical institutions are recommended to consolidate malaria elimination achivements.

[Time to initial diagnosis of imported malaria and its influencing factors in Jiangsu Province].

OBJECTIVE: To investigate the health-seeking behaviors of imported malaria cases after returning to China, and to investigate the factors affecting the time to initial diagnosis, so as to provide the scientific evidence for early identification of imported malaria cases and prevention of severe cases development and secondary transmission. METHODS: The individual demographic features, and the disease onset and the time to initial diagnosis of imported malaria cases in Jiangsu Province in 2019 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China. The characteristics of health-seeking behaviors and epidemiological features of imported malaria cases were descriptively analyzed, and the factors affecting the time to initial diagnosis of imported malaria cases after returning to China were identified using multivariate logistic regression analysis. RESULTS: A total of 244 imported malaria cases were reported in Jiangsu Province in 2019, and the time to initial diagnosis of the cases were 1-12 days, with mean time of (1.53 ± 1.65) days, with median time of one day. The highest number of malaria cases seeking healthcare services were found on the day of developing primary symptoms (76 cases, 31.1%), followed by on the second day (68 cases, 27.9%), on the third day (46 cases, 18.9%), and 54 cases (22.1%) received initial diagnosis 3 days following presence of primary symptoms, including 3 cases with initial diagnosis at more than one week. High proportions of imported malaria cases with a delay in the time to initial diagnosis were seen in migrant workers who returned to China in January (14 cases, 5.7%) and December (13 cases, 5.3%) and those aged between 41 and 50 years (32 cases, 13.1%). Multivariate logistic regression analysis showed relative short time to initial diagnosis among imported malaria cases returning to China on March [odds ratio (OR) = 0.16, P = 0.03, 95% confidence interval (CI): (0.03, 0.85)] and those with a history of overseas malaria parasite infections [OR = 0.36, P = 0.001, 95% CI: (0.19, 0.67)]. CONCLUSIONS: Timely health-seeking behaviors should be improved among imported malaria cases in Jiangsu Province, patients with a history of overseas malaria infections require faster health-seeking activities.

New insights on malaria.

Malaria is long known as a deadly vector borne infection, caused by five parasite species of the coccidian genus Plasmodia that are present in as many as 85 countries. Despite significant progresses have been achieved to control the infection by early diagnosis and artemisinin combination treatment, insecticide-treated nets and indoor residual spraying, malaria still represents a major public health issue in many endemic low-income countries. New diagnostic tools of higher sensitivity and specificity are now available for use in endemic countries to better guide diagnosis and treatment. In particular, highly sensitive rapid antigenic tests are now available and the loop-mediated isothermal amplification is a very promising and highly sensitive diagnostic tool. After 2015, decreasing morbidity and mortality trends have been stagnating because of limited funding, emergence of parasite and vector resistance to drugs and insecticides respectively and, recently, by the disrupting effect of COVID-19 pandemic. The incomplete knowledge of the complex immunity of malaria infection has slowed the development of an effective vaccine. However, in 2021, the RTS-S vaccine, however of suboptimal protective efficacy, has been made available for routine use in children above 5 months of age. Population movements has increased the chance of observing imported malaria in non-endemic areas, where malaria competent vectors may still exist.