Plasmodium malariae is a neglected human malaria parasite with low parasitemia that often results in the misdiagnosis and underestimation of the actual disease burden of this pathogen. Microscopy is the best diagnostic tool, despite the fact that rapid diagnostic tests (RDTs) are the best surveillance tool for malaria diagnosis in many rural areas for their ease of use in elimination settings. For parasite antigen detection other than P. falciparum, RDTs depend on essential glycolytic Plasmodium proteins, i.e., Plasmodium lactate dehydrogenase (pLDH) and Plasmodium aldolase (pAldo) antigens. There is a lack of species-specific test kits for P. malariae, and overall, its rapid antigenic test accuracy is questionable. False negative results can accelerate the burden of asymptomatic malaria infection and transmission. Here, we report a case of a malaria patient in Bangladesh infected with P. malariae who tested negative on pLDH and pAldo based RDTs. This case provides useful information for health providers to be aware of possible RDT failure and also for the future development of analytically sensitive test kits for P. malariae.

BACKGROUND: Panama is one of eight countries in Mesoamerica that aims to eliminate malaria by 2022. Malaria is concentrated in indigenous and remote regions like Guna Yala, a politically autonomous region where access to health services is limited and cases are predominately detected through intermittent active surveillance. To improve routine access to care, a joint effort was made by Guna Yala authorities and the Ministry of Health to pilot a network of community health workers (CHWs) equipped with rapid diagnostic tests and treatment. The impact of this pilot is described.
METHODS: Access to care was measured using the proportion of villages targeted by the effort with active CHWs. Epidemiological impact was evaluated through standard surveillance and case management measures. Tests for differences in proportions or rates were used to compare measures prior to (October 2014-September 2016) and during the pilot (October 2016-September 2018).
RESULTS: An active CHW was placed in 39 (95%) of 41 target communities. During the pilot, CHWs detected 61% of all reported cases from the region. Test positivity in the population tested by CHWs (22%) was higher than in those tested through active surveillance, both before (3.8%) and during the pilot (2.9%). From the pre-pilot to the pilot period, annual blood examination rates decreased (9.8 per 100 vs. 8.0 per 100), test positivity increased (4.2% to 8.5%, Χ2 = 126.3, p < 0.001) and reported incidence increased (4.1 cases per 1000 to 6.9 cases per 1000 [Incidence Rate Ratio = 1.83, 95% CI 1.52, 2.21]). The percent of cases tested on the day of symptom onset increased from 8 to 27% and those treated on the day of their test increased from 26 to 84%.
CONCLUSIONS: The CHW network allowed for replacement of routine active surveillance with strong passive case detection leading to more targeted and timely testing and treatment. The higher test positivity among those tested by CHWs compared to active surveillance suggests that they detected cases in a high-risk population that had not previously benefited from access to diagnosis and treatment. Surveillance data acquired through this CHW network can be used to better target active case detection to populations at highest risk.

BACKGROUND: Community case management of malaria (CCMm) is an equity-focused strategy that complements and extends the reach of health services by providing timely and effective management of malaria to populations with limited access to facility-based healthcare. In Kenya, CCMm involves the use of malaria rapid diagnostic tests (RDT) and treatment of confirmed uncomplicated malaria cases with artemether lumefantrine (AL) by community health volunteers (CHVs). The test positivity rate (TPR) from CCMm reports collected by the Ministry of Health in 2018 was two-fold compared to facility-based reports for the same period. This necessitated the need to evaluate the performance of CHVs in conducting malaria RDTs.
METHODS: The study was conducted in four counties within the malaria-endemic lake zone in Kenya with a malaria prevalence in 2018 of 27%; the national prevalence of malaria was 8%. Multi-stage cluster sampling and random selection were used. Results from 200 malaria RDTs performed by CHVs were compared with test results obtained by experienced medical laboratory technicians (MLT) performing the same test under the same conditions. Blood slides prepared by the MLTs were examined microscopically as a back-up check of the results. A Kappa score was calculated to assess level of agreement. Sensitivity, specificity, and positive and negative predictive values were calculated to determine diagnostic accuracy.
RESULTS: The median age of CHVs was 46 (IQR: 38, 52) with a range (26-73) years. Females were 72% of the CHVs. Test positivity rates were 42% and 41% for MLTs and CHVs respectively. The kappa score was 0.89, indicating an almost perfect agreement in RDT results between CHVs and MLTs. The overall sensitivity and specificity between the CHVs and MLTs were 95.0% (95% CI 87.7, 98.6) and 94.0% (95% CI 88.0, 97.5), respectively.
CONCLUSIONS: Engaging CHVs to diagnose malaria cases under the CCMm strategy yielded results which compared well with the results of qualified experienced laboratory personnel. CHVs can reliably continue to offer malaria diagnosis using RDTs in the community setting.

Following the diagnosis of a falciparum malaria case imported from Djibouti and not detected by a pfHRP2-based rapid diagnostic test (RDT), we investigated the prevalence of the pfhrp2/pfhrp3-deleted parasites in Djibouti using 378 blood samples collected between January and May 2019, from Djiboutian patients with suspected malaria. Malaria diagnosis by quantitative PCR confirmed the presence of Plasmodium falciparum for 20.9% (79/378) samples while RDTs did not detect HRP2 antigen in 83.5% (66/79) of these samples. Quantitative PCRs targeting the pfhrp2/pfhrp3 genes confirmed the absence of both genes for 86.5% of P. falciparum strains. The very large number (86.5%) of falciparum parasites lacking the pfhrp2/pfhrp3 genes observed in this study, now justifies the use of non-HRP2 alternative RDTs in Djibouti. In this area and in most countries where HRP2-based RDTs constitute the main arsenal for falciparum malaria diagnosis, it is important to implement a systematic surveillance and to inform biologists and clinicians about the risk of malaria misdiagnosis. Further investigations are needed to better understand the mechanism of selection and diffusion of the pfhrp2/pfhrp3-deleted parasites.

OBJECTIVE: To perform epidemiological survey and laboratory diagnosis of a Plasmodium ovale malaria case imported into Hefei City, so as to provide scientific evidence for the prevention and control of imported malaria in the future.
METHODS: The epidemiological history and clinical data of the imported malaria case were collected and analyzed.
RESULTS: The patient returned to China from Mozambique, and was admitted to the hospital due to repeated fever several months after returning to China. Rapid diagnostic test (RDT) suggested non-P. falciparum infection, and microscopy displayed normal or slightly swelled malaria parasite-infected erythrocytes, unapparent serrated changes, increased cytoplasm in large trophozoite with irregular morphology, and almost no vacuoles. qPCR assay revealed P. ovale infection.
CONCLUSIONS: Clinical medical professionals should improve their awareness of malaria diagnosis in people with a history of living or working in overseas malaria-epidemic areas, and early and rational administration of antimalarials should be given promptly to prevent the spread of malaria epidemics.
[摘要] 目的 对合肥市 1 例输入性卵形疟病例进行流行病学调查和实验室诊断分析, 为今后预防控制输入性疟疾提 供参考依据。方法 对该例输入性卵形疟患者的流行病学史、诊疗经过等资料进行收集、整理和分析。结果 患者从非 洲莫桑比克务工返乡, 回国数月后因反复发热就医。快速诊断试纸条法 (RDT) 提示为非恶性疟原虫感染; 镜检见被感染 红细胞正常大小或略胀大、锯齿状不明显, 大滋养体胞浆增多、形态不规则、基本无空泡。荧光定量 PCR 确诊该病例为卵 形疟原虫感染。结论 临床医务人员应加强对有境外流行区生活及工作史人员的疟疾诊断意识, 及时早期合理用药, 防 止疟疾疫情扩散。.

Malaria remains one of the leading health burdens in the developing world, especially in several sub-Saharan Africa countries; and Uganda has some of the highest recorded measures of malaria transmission intensity in the world. It is evident that the prevalence of malaria infection, the incidence of disease, and mortality from severe malaria remain very high in Uganda. Although the recent stable political and economic situation in the last few decades in Uganda supported for a fairly good appreciation of malaria control, the declines in infection, morbidity, and mortality are not sufficient to interrupt transmission and this country is among the top 4 countries with cases of malaria, especially among children under 5 years of age. In fact, Uganda, which is endemic in over 95% of the country, is a representative of challenges facing malaria control in Africa. In this study, we evaluated an active case detection program in 6 randomly selected villages, Uganda. This program covered a potential target population of 5,017 individuals. Our team screened 12,257 samples of malaria by active case detection, every 4 months, from February 2015 to January 2017 in the 6 villages (a total of 6 times). This study assessed the perceptions and practices on malaria control in Kiyuni Parish of Kyankwanzi district, Uganda. Our study presents that the incidence of malaria is sustained high despite efforts to scale-up and improve the use of LLINs and access to ACDs, based on the average incidence confirmed by RDTs.

Febrile illnesses are common in travellers returning from south-east Asia. However, malaria is a rare diagnosis in this population. A series of Plasmodium knowlesi infections was noted in German travellers returning from Thailand since 2012. Infectious disease and tropical medicine facilities registered by the German Society for Tropical Medicine and International Health were contacted in March 2017, and asked to report previous P. knowlesi cases. In addition, surveillance data from the Robert Koch-Institute were analysed. The facilities reported a total of six P. knowlesi-positive cases, all were returning travellers from Thailand. The P. knowlesi-positive cases made up 6/9 of all diagnosed malaria cases imported from Thailand in the time period 2012 to 2017. In 4/5 of cases where a malaria rapid diagnostic test had been applied it revealed a negative result. P. knowlesi is an important differential diagnosis in travellers returning from south-east Asia with itineraries that include Thailand. This study highlights the importance of this Plasmodium species in this patient subgroup. Whenever malaria is suspected in a returning traveller from Thailand, P. knowlesi should be taken into consideration and a differential PCR be executed as currently the unequivocal diagnosis of P. knowlesi is based on nuclear amplification techniques.

BACKGROUND: In 2011, the demographic and health survey (DHS) in Cameroon was combined with the multiple indicator cluster survey. Malaria parasitological data were collected, but the survey period did not overlap with the high malaria transmission season. A malaria indicator survey (MIS) was also conducted during the same year, within the malaria peak transmission season. This study compares estimates of the geographical distribution of malaria parasite risk and of the effects of interventions obtained from the DHS and MIS survey data.
METHODS: Bayesian geostatistical models were applied on DHS and MIS data to obtain georeferenced estimates of the malaria parasite prevalence and to assess the effects of interventions. Climatic predictors were retrieved from satellite sources. Geostatistical variable selection was used to identify the most important climatic predictors and indicators of malaria interventions.
RESULTS: The overall observed malaria parasite risk among children was 33 and 30% in the DHS and MIS data, respectively. Both datasets identified the Normalized Difference Vegetation Index and the altitude as important predictors of the geographical distribution of the disease. However, MIS selected additional climatic factors as important disease predictors. The magnitude of the estimated malaria parasite risk at national level was similar in both surveys. Nevertheless, DHS estimates lower risk in the North and Coastal areas. MIS did not find any important intervention effects, although DHS revealed that the proportion of population with an insecticide-treated nets access in their household was statistically important. An important negative relationship between malaria parasitaemia and socioeconomic factors, such as the level of mother\'s education, place of residence and the household welfare were captured by both surveys.
CONCLUSIONS: Timing of the malaria survey influences estimates of the geographical distribution of disease risk, especially in settings with seasonal transmission. In countries with different ecological zones and thus different seasonal patterns, a single survey may not be able to identify all high risk areas. A continuous MIS or a combination of MIS, health information system data and data from sentinel sites may be able to capture the disease risk distribution in space across different seasons.

BACKGROUND: Private sector availability and use of malaria rapid diagnostic tests (RDTs) lags behind the public sector in Kenya. Increasing channels through which quality malaria diagnostic services are available can improve access to testing and help meet the target of universal diagnostic testing. Registered pharmacies are currently not permitted to perform blood tests, and evidence of whether malaria RDTs can be used by non-laboratory private providers in line with the national malaria control guidelines is required to inform ongoing policy discussions in Kenya.
METHODS: Two rounds of descriptive cross-sectional exit interviews and mystery client surveys were conducted at private health facilities and registered pharmacies in 2014 and 2015, 6 and 18 months into a multi-country project to prime the private sector market for the introduction of RDTs. Data were collected on reported RDT use, medicines received and prescribed, and case management of malaria test-negative mystery clients. Analysis compared outcomes at facilities and pharmacies independently for the two survey rounds.
RESULTS: Across two rounds, 534 and 633 clients (including patients) from 130 and 120 outlets were interviewed, and 214 and 250 mystery client visits were completed. Reported testing by any malaria diagnostic test was higher in private health facilities than registered pharmacies in both rounds (2014: 85.6% vs. 60.8%, p < 0.001; 2015: 85.3% vs. 56.3%, p < 0.001). In registered pharmacies, testing by RDT was 52.1% in 2014 and 56.3% in 2015. At least 75% of test-positive patients received artemisinin-based combination therapy (ACT) in both rounds, with no significant difference between outlet types in either round. Provision of any anti-malarial for test-negative patients ranged from 0 to 13.9% across outlet types and rounds. In 2015, mystery clients received the correct (negative) diagnosis and did not receive an anti-malarial in 75.5% of visits to private health facilities and in 78.4% of visits to registered pharmacies.
CONCLUSIONS: Non-laboratory staff working in registered pharmacies in Kenya can follow national guidelines for diagnosis with RDTs when provided with the same level of training and supervision as private health facility staff. Performance and compliance to treatment recommendations are comparable to diagnostic testing outcomes recorded in private health facilities.

OBJECTIVE: To diagnose the first imported case of Plasmodium ovale infection by laboratory detection.
METHODS: The epidemiological data and blood samples of the case were collected, and the samples were detected by the microscopic examination, rapid diagnostic test (RDT) and nested PCR.
RESULTS: The patient was a construction worker backing from Congo, Africa. He experienced the symptoms of irregular fever and weakness one month after returning in Lingyang Town, Junxian County. The results of RDT only suggested no-Plasmodium falciparum infection. Under the microscope, it was seen that the infected RBC were obviously disfigured and in irregular shape, the ring forms were thick and big, and also thick granulas in big trophozoite stage and schizont stage were found. The results of PCR showed that the size of amplified product was about 800 bp, which was conformed to that of P. ovale.
CONCLUSIONS: Though microscopic examination is the golden standard for malaria diagnosis, as P. ovale is difficult to be identified under microscope, the microscopic method combined with PCR test can be used for definite diagnosis.
［摘要］目的 对日照市首例输入性卵形疟病例进行实验室检测, 以明确诊断。方法 收集患者流行病学资料和血样, 分别进行疟疾快速诊断检测 (RDT)、疟原虫镜检及巢式PCR检测。结果 患者从非洲刚果金务工返乡, 回居住地莒县陵 阳镇1个月后出现不规则发热、乏力。RDT检测提示为非恶性疟原虫感染。血涂片镜下可见感染红细胞明显变形, 呈多 种不规则形状; 环状体粗大, 可见大滋养体期和裂殖体期疟原虫。巢式PCR扩增基因产物长度约800 bp, 与卵形疟原虫 相符。综合上述结果, 该病例诊断为单一卵形疟原虫感染。结论 虽然镜检是疟疾诊断的金标准, 但卵形疟原虫在镜下 很难鉴别, 结合PCR检测结果可明确诊断。.