Mixed Plasmodium Research Articles

Prevalence of Clinical Artesunate Resistance among Cases of Complicated Malaria in Southern Odisha, India

Introduction: Drug resistant malaria represents the most challenging health problem worldwide. The major threat to malaria control is the increasing incidence of complicated and drug-resistant cases. Aim: To determine the prevalence of clinical artesunate resistance among complicated malaria cases by invivo method. Materials and Methods: The study included 241 patients with complicated malaria, which showed trophozoites of malarial parasite Plasmodium in the blood smear. They were administered with artesunate monotherapy. They were then followed-up for clinical response to therapy and quantification of parasitaemia levels on day 1, day 2, day 3, day 7, day 14 and day 28. Clinical examination included core body temperature recording, assessment of associated complications like vomiting, altered sensorium, anaemia, bleeding tendencies and investigation of renal parameters, liver function test and hypoglycaemia. Results: Out of 241 complicated malaria cases showing malarial parasite in peripheral blood smear, 204 cases were of Plasmodium falciparum, 32 cases were of Plasmodium vivaxand five were cases of mixed Plasmodium falciparum and Plasmodium vivax infection. Among the 241 malaria positive cases, the most commonly associated complication was severe anaemia in 87 (36.1%) cases. All the 32 cases of Plasmodium vivax malaria and the five cases of mixed infection responded and recovered after administration of artesunate monotherapy. But among the 204 cases of Plasmodium falciparum, clinical artesunate resistance was detected in 6 (2.94%) cases and the rest 198 (97.06%) cases were sensitive to artesunate monotherapy. Conclusion: Clinical artesunate resistance was noticed in 2.94% cases of Plasmodium falciparum malaria. Hence, continuous monitoring of antimalarial therapy is required, especially in complicated cases of Plasmodium falciparum malaria, to prevent the emergence of artesunate resistance.

Management of uncomplicated malaria in private health facilities in North-West Ethiopia: a clinical audit of current practices

BackgroundMalaria is one of the leading public health problems in sub-Saharan Africa that contributes to significant patient morbidity and mortality. The aim of the study was to investigate adherence to malaria diagnosis and treatment guidelines by private health sector providers and compare their performance against the public private partnership (PPP) status.MethodsA facility-based retrospective clinical audit was conducted between October 2016 and January 2017 in 11 medium clinics in the West Gojjam zone of the Amhara Region, North-west Ethiopia. Data was extracted from patient medical records using pretested data abstraction forms. Descriptive statistics were employed to present the findings and adherence of health workers against the national and international standards were classified as ideal, acceptable, minor error and major error for both malaria diagnosis and treatment. A chi-square (X2) test was used to test for a statistically significant relationship after the data had been categorized using public private partnership status at P < 0.05.ResultsOne thousand six hundred fifty clinical files were audited. All malaria suspected patients were investigated either with microscopy or rapid diagnostics test (RDT) for parasitological confirmation. The proportion of malaria treated cases was 23.7% (391/1650). Of which 16.6% (274/1650) were uncomplicated, 3.69% (61 /1650) were severe and complicated and the rest 3.39% (56/1650) were clinical diagnosed malaria cases. And the malaria parasite positivity rate was 20.30% (335/1650). All malaria suspected patients were not investigated with ideal malaria diagnosis recommendations; only 19.4% (320/1650) were investigated with acceptable malaria diagnosis (public private partnership (PPP) 19.4%; 176/907; and non-public private partnership (NPPP) 19.38%; 144/743, X2 (1) = 0.0With regards to treatments of malaria cases, the majority 82.9% of Plasmodium vivax cases were managed with ideal recommended treatment (X2 (1) = 0.35, P = 0.55); among Plasmodium falciparum, mixed (Plasmodium falciparum and Plasmodium vivax).ConclusionThe clinical audit revealed that the majority of malaria patients had received minor error malaria diagnostic services. In addition, only one fifth of malaria patients had received ideal malaria treatment services. To understand the reasons for the low levels of malaria diagnosis and treatment adherence with national guidelines, a qualitative exploratory descriptive study is recommended.

Presence and diversity of mixed avian Plasmodium spp. infections in introduced birds whose distribution overlapped with threatened New Zealand endemic birds

ABSTRACTAims: To determine the presence of infection and co-infection of Plasmodium lineages in introduced birds at translocation sites for the North Island saddleback (Philesturnus rufusater), to investigate their role as Plasmodium spp. reservoirs.Methods: Blood samples were collected from introduced bird species, with a special focus on blackbirds (Turdus merula) and song thrushes (Turdus philomelos), at six locations in the North Island of New Zealand that were the origin, or translocation sites, for North Island saddleback. Where available, blood smears were examined, and blood samples were tested using nested PCR with subsequent sequence analysis, for the presence of Plasmodium spp.Results: Of the 55 samples tested using PCR analysis, 39 (71%) were positive for Plasmodium spp., and 28/40 (62%) blood smears were positive for Plasmodium spp. Overall, 31 blood samples were from blackbirds with 28/31 (90%) samples positive for Plasmodium spp. Six distinct avian Plasmodium lineages were identified, including three cosmopolitan lineages; Plasmodium vaughani SYAT05 was detected in 16 samples, Plasmodium matutinum Linn1 in 10 samples and Plasmodium elongatum GRW6 in eight samples. Mixed infections with more than one lineage were detected in 12 samples. Samples from two Australian magpies (Gymnorhina tibicen) were positive for Plasmodium. sp. lineage MYNA02, previously not identified in New Zealand.Conclusions and clinical relevance: This is the first report from New Zealand in which specific Plasmodium spp. mixed infections have been found in introduced birds. Co-infections with several cosmopolitan Plasmodium lineages were identified, as well as the first report in New Zealand of an exotic avian Plasmodium sp. lineage, in Australian magpies. Whilst the role of introduced birds in maintaining and spreading pathogenic avian malaria in New Zealand is unclear, there is a potential infection risk to native birds, especially where distributions overlap.

Accuracy of malaria diagnosis by clinical laboratories in Belgium

BackgroundThe Belgian Reference Laboratory for Plasmodium offers a free-of-charge reference testing of malaria-positive or doubtful samples to clinical laboratories.MethodsThe final malaria diagnosis from the Reference Laboratory (microscopy, rapid diagnostic tests (RDTs) and Plasmodium species-specific PCR) were compared with the final diagnosis from peripheral Belgian laboratories. The Reference Laboratory reports were analysed for all samples submitted between 2013 and 2017. Criteria assessed included the diagnosis of malaria, Plasmodium species identification including mixed infections, and in case of Plasmodium falciparum, the parasite density and the presence of sexual and asexual stages.ResultsA total of 947 non-duplicate samples were included. Reference testing confirmed 96.3% (893/927) and 90.0% (18/20) samples submitted as positive and negative, respectively, the two missed diagnoses were samples with Plasmodium ovale and Plasmodium malariae. Submitting laboratories had correctly identified P. falciparum in 95.1% (508/534) samples with P. falciparum single infection. They had correctly diagnosed the species in 62.9% (95/151) single non-falciparum samples and had reported ‘non-falciparum’ in another 26 (17.2%) samples; most errors occurred among P. malariae (n = 8/21, 38.1%) and P. ovale (n = 14/51, 27.5%). Only one of the 21 mixed Plasmodium species infections had been diagnosed as such by the submitting laboratories; in three of them, P. falciparum had been overlooked. Taken single and mixed infections together, P. falciparum was diagnosed in 98.6% (546/554) samples. Among 471 single P. falciparum samples available for comparison, laboratories had correctly reported parasite densities above 2% in 87.5% (70/80) samples; they had incorrectly reported parasite densities > 2% in an extra 52 (8.9%) samples. Laboratories had correctly reported P. falciparum schizonts and gametocytes in 25.6% (11/43) and 56.7% (17/30) samples, respectively.ConclusionDiagnostic laboratories in a malaria non-endemic setting provided excellent diagnosis of malaria and P. falciparum, reasonably good diagnosis of non-falciparum infections and acceptable calculation of P. falciparum parasite density.

Assessment of Malaria Microscopic Diagnosis Performance of Laboratory Professionals in Addis Ababa’s Public Health Facilities

Cross-sectional study was conducted using panel blood films and questioner to assess detection & identification performance of laboratory professionals’ and identify factors affecting the performance of malaria microscopic diagnosis. Study participants had 91.7% (95% CI: 89.96 – 93.44) agreement for detection of malaria parasites, 67.63% (95% CI: 64.91 – 70.35) species identification agreement for Plasmodium falciparum, 5.08% false positive and 21.04% false negative results. Correct species identification percentage for Plasmodium falciparum were 60.9% (510), Plasmodium vivax 59.17% (371) and Mixed (Plasmodium falciparum and Plasmodium vivax) 25% (53) were also identified in the study. In addition, sensitivity 94.69% (95% CI: 93.02 – 96.36) and specificity of 79.71 (95% CI: 75.22 – 84.2) were calculated from panel blood film results. The most frequent type of misdiagnosis was 85(40.09%) mixed BFs diagnosed as Plasmodium vivax, 67 (31.6%) mixed BFs as Plasmodium falciparum and 218(26%) Plasmodium falciparum BFs as Plasmodium vivax. Moreover, only 18(8.5%) laboratory professionals were participated in external quality assessment. From multiple logistic regression analysis training was the major factor for species identification percent agreement performance improvement of laboratory professionals. It showed statistical significance with p-value < 0.05 and untrained laboratory professionals were 64% less likely to perform ≥ 85% agreement of species identification. Training of laboratory professionals on malaria microscopic diagnosis help to improve the accuracy and reliability of reported results. This will help to provide the right and recommended medication and patient management.

Frozen blood clots can be used for the diagnosis of distinct Plasmodium species in man and non-human primates from the Brazilian Atlantic Forest

BackgroundZoonotic infections with epidemic potential, as non-human primate malaria and yellow fever (YF), can overlap geographically. Optimizing a small blood sample for diagnosis and surveillance is of great importance. Blood are routinely collected for YF diagnosis and blood clots usually discarded after serum obtention. Aiming to take sample advantage, the sensitivity of a PCR using extracted DNA from long-term frozen clots from human and non-human primates for detection of Plasmodium spp. in low parasitaemia conditions was assayed.ResultsMalaria diagnosis with DNA extracted from blood clots generated results in agreement with samples obtained with whole blood, including mixed Plasmodium vivax/simium and Plasmodium malariae/brasilianum infections.ConclusionBlood clots from human and non-human primates may be an important and low cost source of DNA for malaria surveillance in the Atlantic Forest.

Manifestation of malaria in Mangaluru, southern India

BackgroundSevere and fatal vivax malaria is increasingly reported from India. In Mangaluru, southern India, malaria is focused in urban areas and associated with importation by migrant workers. In Wenlock Hospital, the largest governmental hospital, the clinical, parasitological and biochemical characteristics of malaria patients were assessed.MethodsDuring the peak malaria season in 2015 (June to December), outpatients were interviewed and clinically assessed. Malaria was ascertained by microscopy and PCR assays, concentrations of haemoglobin, creatinine and bilirubin, as well as thrombocyte count, were determined, and severe malaria was defined according to WHO criteria.ResultsAmong 909 malaria patients, the vast majority was male (93%), adult (median, 26 years) and of low socio-economic status. Roughly half of them were migrants from beyond the local Karnataka state, mostly from northern and northeastern states. Vivax malaria (69.6%) predominated over mixed Plasmodium vivax–Plasmodium falciparum infection (21.3%) and falciparum malaria (9.0%). The geometric mean parasite density was 3412/µL. As compared to vivax malaria, patients with falciparum malaria had higher parasite density and more frequently showed impaired general condition, affected consciousness and splenomegaly. Also, they tended to more commonly have anaemia and increased creatinine levels, and to be hospitalized (7.3%). Mixed-species infections largely assumed an interim position. Severe malaria (3.5%) was not associated with parasite species. No fatality occurred.ConclusionIn this study, uncomplicated cases of malaria predominated, with P. falciparum causing slightly more intense manifestation. Severe malaria was infrequent and fatalities absent. This contrasts with the reported pattern of manifestation in other parts of India, which requires the analysis of underlying causes.

Spatiotemporal Clustering Analysis of Malaria Infection in Pakistan.

Despite tremendous progress, malaria remains a serious public health problem in Pakistan. Very few studies have been done on spatiotemporal evaluation of malaria infection in Pakistan. The study aimed to detect the spatiotemporal pattern of malaria infection at the district level in Pakistan, and to identify the clusters of high-risk disease areas in the country. Annual data on malaria for two dominant species (Plasmodium falciparum, Plasmodium vivax) and mixed infections from 2011 to 2016 were obtained from the Directorate of Malaria Control Program, Pakistan. Population data were collected from the Pakistan Bureau of Statistics. A geographical information system was used to display the spatial distribution of malaria at the district level throughout Pakistan. Purely spatiotemporal clustering analysis was performed to identify the high-risk areas of malaria infection in Pakistan. A total of 1,593,409 positive cases were included in this study over a period of 6 years (2011–2016). The maximum number of P. vivax cases (474,478) were reported in Khyber Pakhtunkhwa (KPK). The highest burden of P. falciparum (145,445) was in Balochistan, while the highest counts of mixed Plasmodium cases were reported in Sindh (22,421) and Balochistan (22,229), respectively. In Balochistan, incidence of all three types of malaria was very high. Cluster analysis showed that primary clusters of P. vivax malaria were in the same districts in 2014, 2015 and 2016 (total 24 districts, 12 in Federally Administered Tribal Areas (FATA), 9 in KPK, 2 in Punjab and 1 in Balochistan); those of P. falciparum malaria were unchanged in 2012 and 2013 (total 18 districts, all in Balochistan), and mixed infections remained the same in 2014 and 2015 (total 7 districts, 6 in Balochistan and 1 in FATA). This study indicated that the transmission cycles of malaria infection vary in different spatiotemporal settings in Pakistan. Efforts in controlling P. vivax malaria in particular need to be enhanced in high-risk areas. Based on these findings, further research is needed to investigate the impact of risk factors on transmission of malaria in Pakistan.

Clinical Outcomes of Submicroscopic Infections and Correlates of Protection of VAR2CSA Antibodies in a Longitudinal Study of Pregnant Women in Colombia.

Malaria in pregnancy can cause serious adverse outcomes for the mother and the fetus. However, little is known about the effects of submicroscopic infections (SMIs) in pregnancy, particularly in areas where Plasmodium falciparum and Plasmodium vivax cocirculate. A cohort of 187 pregnant women living in Puerto Libertador in northwest Colombia was followed longitudinally from recruitment to delivery. Malaria was diagnosed by microscopy, reverse transcription-quantitative PCR (RT-qPCR), and placental histopathology. Gestational age, hemoglobin concentration, VAR2CSA-specific IgG levels, and adhesion-blocking antibodies were measured during pregnancy. Statistical analyses were performed to evaluate the impact of SMIs on birth weight and other delivery outcomes. Twenty-five percent of women (45/180) were positive for SMIs during pregnancy. Forty-seven percent of infections (21/45) were caused by P. falciparum, 33% were caused by P. vivax, and 20% were caused by mixed Plasmodium spp. Mixed infections of P. falciparum and P. vivax were associated with lower gestational age at delivery (P = 0.0033), while other outcomes were normal. Over 60% of women had antibodies to VAR2CSA, and there was no difference in antibody levels between those with and without SMIs. The anti-adhesion function of these antibodies was associated with protection from SMI-related anemia at delivery (P = 0.0086). SMIs occur frequently during pregnancy, and while mixed infections of both P. falciparum and P. vivax were not associated with a decrease in birth weight, they were associated with significant risk of preterm birth. We propose that the lack of adverse delivery outcomes is due to functional VAR2CSA antibodies that can protect pregnant women from SMI-related anemia.

Cryptic Plasmodium ovale concurrent with mixed Plasmodium falciparum and Plasmodium malariae infection in two children from Central African Republic

BackgroundSince several malaria parasite species are usually present in a particular area, co-infections with more than one species of Plasmodium are more likely to occur in humans infected in these areas. In many mixed infections, parasite densities of the cryptic species may be low and often not recognized in clinical practice.Case presentationTwo children (3 and 6 years old) adopted recently from Central African Republic were admitted to hospital because of intermittent fever. Thin blood smears stained with Giemsa showed Plasmodium falciparum and Plasmodium malariae co-infection for both children at admission. They were both treated with atovaquone-proguanil combination for 3 days. At day 7, both thin blood smears examination remained negative but at day 28, thin blood smear was positive for P. malariae trophozoites and for Plasmodium ovale for the girl and her brother, respectively. Samples collected at day 1 and day 28 were submitted to real-time PCR showing the presence of the three parasite species (P. falciparum, P malariae and P. ovale) in admission blood samples from the two children and only P. ovale at day 28.ConclusionsTwenty-eight days follow-up after treatment led to detection of a third parasite species in the blood of these two patients suggesting covert co-infection and a delayed appearance of one cryptic species following treatment. Concurrently infecting malaria species could be mutually suppressive, with P. falciparum tending to dominate other species. These observations provide more evidence that recommendations for treatment of imported malaria should take into account the risk of concurrent or cryptic infection with Plasmodium species. Clinicians and biologists should be aware of the underestimated frequency of mixed infections with cryptic species and of the importance of patient follow-up at day 28. Future guidelines should shed more light on the treatment of mixed infection and on the interest of using artemisinin-based combinations for falciparum and non-falciparum species.

Epidemiological analysis of malaria prevalence in Jiangsu Province in 2015

Objective To understand the malaria epidemic situation and characteristics in Jiangsu Province in 2015, so as to provide the evidence for malaria elimination. Methods The data of malaria cases in Jiangsu Province in 2015 were collected from China's routine diseases surveillance information system. Results Totally 405 imported cases were reported in Jiangsu Province in 2015, and the cases increased by 14.08% compared with those in 2014. All the malaria cases were imported, and 5 cases (1.23%) were from Southeast Asia and 400 (98.77%) were from 25 African countries or regions. The imported malaria cases were reported in 13 cities across Jiangsu Province, where Taizhou, Lianyungang, Nantong, Huaian and Yangzhou cities accounted for 68.64% of all the cases in the province. Jiangsu Institute of Parasitic Diseases (JIPD) reference lab checked all the cases and classified 299 falciparum malaria cases, 13 vivax malaria cases, 18 quartan malaria cases, 71 ovale malaria cases, and 4 mixed Plasmodium infection cases. Conclusions In Jiangsu Province, there are no local malaria cases for 4 consecutive years, but the imported cases are on the rise. Compared to 2014, the imported vivax cases increased significantly in 2015. It should be the key points to strengthen the surveillance of imported malaria cases, improve malaria diagnosis and treatment abilities for all levels of medical institutions, and promote the abilities of Plasmodium check, and focus survey and disposal of all Center for Disease Control (CDC) staffs across Jiangsu Province.

Molecular investigation of sub-microscopic and mixed Plasmodium species infection in North-Central Nigeria

Molecular investigation of sub-microscopic and mixed Plasmodium species infection in North-Central Nigeria

Can Mixed Parasite Infections Thwart Targeted Malaria Elimination Program in India?

India is highly endemic to malaria with prevalence of all five species of human malaria parasites of Plasmodium genus. India is set for malaria elimination by 2030. Since cases of mixed Plasmodium species infections remain usually undetected but cause huge disease burden, in order to understand the distributional prevalence of both monospecies infections and mixed species infections in India, we collated published data on the differential infection incidences of the five different malaria parasites based on PCR diagnostic assay. About 11% of total cases were due to mixed species infection. Among several interesting observations on both single and mixed parasitic infections, incidences of Plasmodium falciparum monoinfection were found to be significantly higher than P. vivax monoinfection. Also, P. malariae seems to be emerging as a potential malaria threat in India. Putting all the facts together, it appears that the dream of achieving malaria elimination in India will not be completely successful without dealing with mixed species infection.

Frequency and distribution of mixed Plasmodium falciparum-vivax infections in French Guiana between 2000 and 2008.

BackgroundThe two main plasmodial species in French Guiana are Plasmodium vivax and Plasmodium falciparum whose respective prevalence influences the frequency of mixed plasmodial infections. The accuracy of their diagnosis is influenced by the sensitivity of the method used, whereas neither microscopy nor rapid diagnostic tests allow a satisfactory evaluation of mixed plasmodial infections.MethodsIn the present study, the frequency of mixed infections in different part of French Guiana was determined using real time PCR, a sensitive and specific technique.ResultsFrom 400 cases of malaria initially diagnosed by microscopy, real time PCR showed that 10.75 % of the cases were mixed infections. Their prevalence varied considerably between geographical areas. The presence, in equivalent proportions, of the two plasmodial species in eastern French Guiana was associated with a much higher prevalence of mixed plasmodial infections than in western French Guiana, where the majority of the population was Duffy negative and thus resistant to vivax malaria.ConclusionClinicians must be more vigilant regarding mixed infections in co-endemic P. falciparum/P. vivax areas, in order to deliver optimal care for patients suffering from malaria. This may involve the use of rapid diagnostic tests capable of detecting mixed infections or low density single infections. This is important as French Guiana moves towards malaria elimination.

Detection of Mixed Infections with Plasmodium spp. by PCR, India, 2014.

In 8 malaria-endemic states in India, mixed Plasmodium spp. infections were detected by PCR in 17.4% (265/1,521) of blood samples that microscopy had shown to contain only P. falciparum. The quality of microscopy must be improved because use of PCR for detection of malaria parasites is limited in rural areas.

Past five-year trend, current prevalence and household knowledge, attitude and practice of malaria in Abeshge, south-central Ethiopia.

BackgroundIn Ethiopia malaria remains a leading cause of outpatient consultation despite massive control efforts. This study was aimed at analysing 5-year retrospective trend and current prevalence of malaria as well as community knowledge, attitude and practice (KAP) in Walga Health Centre (WHC) catchment area in Abeshge District, south-central Ethiopia.MethodsA cross-sectional, household survey was conducted to determine malaria prevalence and KAP in December 2013. Further, malaria cases reported from WHC in 2008–2012 were extracted. A multi-stage, random sampling technique was used to select study participants from four kebeles. Of 800 participants, 400 were interviewed to assess their KAP about malaria and the other half were recruited for malaria microscopy.ResultsOverall, 11,523 (33.8 %) slide-confirmed malaria cases were reported (no fatalities) among 34,060 outpatients diagnosed in 2008–2012. There was successively significant decline in malaria prevalence from 2009 onwards although a significant rise was noticed in 2009 compared to 2008 (p <0.0001). Male malaria suspects (17,626) were significantly higher than of females (16,434) (p = 0.0127) but malaria prevalence was not significantly variable between sexes. Individuals who were ≥15 years constituted 44.9 % of the patients. Although most participants (78.8 %) associated mosquito bites with malaria, the remaining mentioned exposure to rain or body contact with malaria patients as causes of malaria. Mosquito nets, draining stagnant water and indoor residual spraying were the most frequently mentioned malaria preventive measures. In the parasitological survey, a single individual (0.25 %) with mixed Plasmodium falciparum-Plasmodium vivax infections was found.ConclusionAlthough malaria remains a primary cause of outpatient admission in WHC, the retrospective data showed a significantly declining trend. This together with the very low prevalence in the current parasitological survey suggests the effectiveness of ongoing control interventions in the locality.

Patterns of mixed Plasmodium species infections among children six years and under in selected malaria hyper-endemic communities of Zambia: population-based survey observations.

BackgroundAlthough malaria is preventable and treatable, it still claims 660,000 lives every year globally with children under five years of age having the highest burden. In Zambia, malaria rapid diagnostic tests (RDTs) that only detect Plasmodium falciparum are the main confirmatory means for malaria diagnosis in most health facilities without microscopy services. As a consequence of this P. falciparum species diagnostic approach, non-falciparum malaria is not only under-diagnosed but entirely missed, thereby making the exact disease burden unknown. We thus investigated the prevalence of various Plasmodium spp. and associated burden of infection in selected communities in Zambia.MethodsData from two malaria hyper-endemic provinces (Eastern and Luapula) of the 2012 National Malaria Indicator Survey (MIS), conducted between April and May 2012, were used. The MIS is a nationally representative, two-stage cluster survey conducted to coincide with the end of the malaria transmission season. Social, behavioural and background information were collected from households as part of the survey. Thick blood smears, RDTs and dried blood spots (DBS) were collected from children below six years of age. Slides were stained using Giemsa and examined by microscopy while polymerase chain reaction (PCR) was used to analyse the DBS for malaria Plasmodium spp. Multivariate logistic regression was employed to examine the association between background factors and malaria.ResultsOverall, 873 children younger than six years of age were surveyed. The overall prevalence of Plasmodium spp. by PCR was 54.3% (95% CI 51–57.6%). Of the total Plasmodium isolates, 88% were P. falciparum, 10.6% were mixed infections and 1.4% were non-falciparum mono infections. Among the mixed infections, the majority were a combination of P. falciparum and P. malariae (6.5% of all mixed infections). Children two years and older (2–5 years) had three-fold higher risk of mixed malaria infections (aOR 2.8 CI 1.31–5.69) than children younger than two years of age.ConclusionThe high prevalence of mixed Plasmodium spp. infections in this population stresses review of the current malaria RDT diagnostic approaches. The observed less incidence of mixed infections in children under two years of age compared to their older two-to-five-year-old counterparts is probably due to the protective maternal passive immunity, among other factors, in that age group.

External Quality Assessment of Malaria Microscopy in Hawassa Health Facilities, Southern Ethiopia

Background: Misinterpretation of malaria microscopy results can lead to inappropriate case management of malaria. The objective of this study was to assess the quality of malaria microscopy among health facilities in Hawassa city. A cross - sectional study was conducted to assess the quality of malaria microscopy diagnosis in Hawassa city health facility laboratories from November 2012 to January 2013 in Sothern Ethiopia. Validated panel malaria slides were distributed to health facilities accompanied with a questionnaire that assessed factors related to malaria microscopy improvement. Operational definitions for correct result and major and minor errors were outlined. A total of 51 laboratory professionals in 10 health facilities were surveyed with a response rate of 85%. Results were collected and data was analyzed by SPSS, and Win Pepi software. Result: Of 306 malaria slides examined in Sample 1-Sample 6 [S1-S6] only 54% of the examinations reported correctly. Considering major errors in [S1-S4], the most common errors were reporting negative for positive slide 39/83(47%), species identification error 29/83(35%) and density 15/83 (18%). In mixed Plasmodium falciparum/Plasmodium vivax (Pf/Pv) sample, only 18% of participants made correct diagnosis in identifying both Pf/Pv species. In Plasmodium negative sample 45(88.2%) of participants scored (no parasites observed) correctly. Considering S1-S4, 29 of the 165 densities reported were different from the reference density established for each slide. 53% of participants had never participated in a formal training on malaria microscopy, and among those who did, more than half were trained earlier than 2008. All of the participants reported to use tap water in preparation of working Giemsa solution. Conclusion: The present assessment revealed a poor quality of malaria microscopy in Hawassa city administration health facilities. Therefore, responsible bodies are required to improve quality of malaria microscopy, and also provide regular refreshment training for laboratory professionals in malaria microscopy. Further similar study should be conducted in large scale.

A Bayesian approach to inferring the phylogenetic structure of communities from metagenomic data.

Metagenomics provides a powerful new tool set for investigating evolutionary interactions with the environment. However, an absence of model-based statistical methods means that researchers are often not able to make full use of this complex information. We present a Bayesian method for inferring the phylogenetic relationship among related organisms found within metagenomic samples. Our approach exploits variation in the frequency of taxa among samples to simultaneously infer each lineage haplotype, the phylogenetic tree connecting them, and their frequency within each sample. Applications of the algorithm to simulated data show that our method can recover a substantial fraction of the phylogenetic structure even in the presence of high rates of migration among sample sites. We provide examples of the method applied to data from green sulfur bacteria recovered from an Antarctic lake, plastids from mixed Plasmodium falciparum infections, and virulent Neisseria meningitidis samples.

A lab-on-chip for malaria diagnosis and surveillance.

BackgroundAccess to timely and accurate diagnostic tests has a significant impact in the management of diseases of global concern such as malaria. While molecular diagnostics satisfy this need effectively in developed countries, barriers in technology, reagent storage, cost and expertise have hampered the introduction of these methods in developing countries. In this study a simple, lab-on-chip PCR diagnostic was created for malaria that overcomes these challenges.MethodsThe platform consists of a disposable plastic chip and a low-cost, portable, real-time PCR machine. The chip contains a desiccated hydrogel with reagents needed for Plasmodium specific PCR. Chips can be stored at room temperature and used on demand by rehydrating the gel with unprocessed blood, avoiding the need for sample preparation. These chips were run on a custom-built instrument containing a Peltier element for thermal cycling and a laser/camera setup for amplicon detection.ResultsThis diagnostic was capable of detecting all Plasmodium species with a limit of detection for Plasmodium falciparum of 2 parasites/μL of blood. This exceeds the sensitivity of microscopy, the current standard for diagnosis in the field, by ten to fifty-fold. In a blind panel of 188 patient samples from a hyper-endemic region of malaria transmission in Uganda, the diagnostic had high sensitivity (97.4%) and specificity (93.8%) versus conventional real-time PCR. The test also distinguished the two most prevalent malaria species in mixed infections, P. falciparum and Plasmodium vivax. A second blind panel of 38 patient samples was tested on a streamlined instrument with LED-based excitation, achieving a sensitivity of 96.7% and a specificity of 100%.ConclusionsThese results describe the development of a lab-on-chip PCR diagnostic from initial concept to ready-for-manufacture design. This platform will be useful in front-line malaria diagnosis, elimination programmes, and clinical trials. Furthermore, test chips can be adapted to detect other pathogens for a differential diagnosis in the field. The flexibility, reliability, and robustness of this technology hold much promise for its use as a novel molecular diagnostic platform in developing countries.