There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Accurate diagnosis of malaria is essential for identification and subsequent treatment of the disease. Currently, microscopy and rapid diagnostic tests are the most commonly used diagnostics, next to treatment based on clinical signs only. These tests are easy to deploy, but have a relatively high detection limit. With declining prevalence in many areas, there is an increasing need for more sensitive diagnostics. Molecular tools may be a suitable alternative, although costs and technical requirements currently hamper their implementation in resource limited settings. A range of (near) point-of-care diagnostics is therefore under development, including simplifications in sample preparation, amplification and/or read-out of the test. Accuracy data, in combination with technical characteristics, are essential in determining which molecular test, if any, would be the most promising to be deployed. This review presents a comprehensive overview of the currently available molecular malaria diagnostics, ranging from well-known tests to platforms in early stages of evaluation, and systematically evaluates their published accuracy. No important difference in accuracy was found between the most commonly used PCR-based assays (conventional, nested and real-time PCR), with most of them having high sensitivity and specificity, implying that there are no reasons other than practical ones to choose one technique over the other. Loop-mediated isothermal amplification and other (novel) diagnostics appear to be highly accurate as well, with some offering potential to be used in resource-limited settings.

Molecular malaria diagnostics: A systematic review and meta-analysis

Background
In Yucatan State, southern Mexico, as in many other parts of the world where tilapia has been introduced for aquaculture, the deficient application of management measures has led to the establishment of non-native parasites. The aims of this study were to describe the geographical distribution of protozoan and helminth parasites of farmed Nile tilapia Oreochromis niloticus (L.) throughout the Yucatan and to examine the potential statistical associations of the prevalence and mean abundance of these parasites with management and environmental variables.

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Geographical distribution of protozoan and metazoan parasites of farmed Nile tilapia Oreochromis niloticus (L.) (Perciformes: Cichlidae) in Yucatán, México

Molecular surveillance of pfhrp2 and pfhrp3 genes deletion in Plasmodium falciparum isolates and the implications for rapid diagnostic tests in Nigeria

This study highlights the value of museum collections in invasion biology. It focuses on introduced tilapias, Oreochromis niloticus and Coptodon rendalli in the Congo Basin and their monogenean (Platyhelminthes) gill parasite fauna. O. niloticus was introduced throughout the Congo Basin while C. rendalli was introduced into the Lower Congo, but is native to the Middle and Upper Congo. In order to study the impact of these stocking events on the native parasite community we investigate the co-introduction and host switching of their parasites. Post-introduction material is compared with pre-introduction samples from museum collections of 5 native tilapias in the Congo Basin. Nine of the known parasites of O. niloticus were co-introduced, while one, Cichlidogyrus rognoni, is missing and possibly not established. In contrast, no parasite species were found co-introduced with C. rendalli into the Lower Congo. The parasite fauna of Tilapia sparrmanii shared no species with O. niloticus. Oreochromis mweruensis shared five species with O. niloticus, but these were also found on the pre-introduction samples, and are considered native to both hosts. We report three putative host switches: Cichlidogyrus sclerosus and Cichlidogyrus tilapiae to Coptodon tholloni in the Lower Congo Basin and Gyrodactylus nyanzae to C. rendalli in the Upper Congo.

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Historical museum collections help detect parasite species jumps after tilapia introductions in the Congo Basin

This study compares the performance of clinical diagnosis and three laboratory diagnostic methods (thick film microscopy (TFM), rapid diagnostic test (RDT), and polymerase chain reaction (PCR)) for the diagnosis of Plasmodium falciparum in Nigeria. Using clinical criteria, 217 children were recruited into the study out of which 106 (48.8%) were positive by TFM, 84 (38.7%) by RDT, and 125 (57.6%) by PCR. Using a composite reference method generated from the three diagnostic methods, 71 (32.7%) patients were found to be truly infected and 90 (41.5%) truly uninfected, while 56 (25.8%) were misidentified as infected or noninfected. When each of the 3 diagnostic methods was compared with the composite reference, PCR had sensitivity of 97.3%, specificity of 62.5%, positive predictive value (PPV) of 56.8%, and negative predictive value (NPV) of 97.8%; microscopy had sensitivity of 77.2%, specificity of 72%, PPV of 66.9%, and NPV of 81.1%, while RDT had sensitivity of 62.3%, specificity of 87.4%, PPV of 67.7%, and NPV of 84.5%. PCR test performed best among the three methods followed by TFM and RDT in that order. The result of this study shows that clinical diagnosis cannot be relied upon for accurate diagnosis of P. falciparum in endemic areas.

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Assessment of Clinical Diagnosis, Microscopy, Rapid Diagnostic Tests, and Polymerase Chain Reaction in the Diagnosis of Plasmodium Falciparum in Nigeria

Olunike Olayeni Adegbosin

Papers

Assessment of Clinical Diagnosis, Microscopy, Rapid Diagnostic Tests, and Polymerase Chain Reaction in the Diagnosis of Plasmodium Falciparum in Nigeria