Cytokine responses during acute simian Plasmodium cynomolgi and Plasmodium knowlesi infections.

Praba-Egge, Anita D.; Montenegro, Sonia; Cogswell, Frank B.; Hopper, Terryl; James, Mark A.

doi:10.4269/ajtmh.2002.67.586

Cited by 25 publications

(18 citation statements)

References 21 publications

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“…It is not understood what is causing the death of heavily infected mosquitoes. One possibility is that there is something toxic in the blood of monkeys that have high levels of P. knowlesi infection, such as a cytokine [42], which might be detrimental to mosquitoes. However, if a toxic substance was ingested, mosquito mortality might be expected to be highest soon after they fed on an infected monkey.…”

Section: Discussionmentioning

confidence: 99%

Using infective mosquitoes to challenge monkeys with Plasmodium knowlesi in malaria vaccine studies

Murphy

Weiss

Fryauff

et al. 2014

Malar J

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BackgroundWhen rhesus monkeys (Macaca mulatta) are used to test malaria vaccines, animals are often challenged by the intravenous injection of sporozoites. However, natural exposure to malaria comes via mosquito bite, and antibodies can neutralize sporozoites as they traverse the skin. Thus, intravenous injection may not fairly assess humoral immunity from anti-sporozoite malaria vaccines. To better assess malaria vaccines in rhesus, a method to challenge large numbers of monkeys by mosquito bite was developed.MethodsSeveral species and strains of mosquitoes were tested for their ability to produce Plasmodium knowlesi sporozoites. Donor monkey parasitaemia effects on oocyst and sporozoite numbers and mosquito mortality were documented. Methylparaben added to mosquito feed was tested to improve mosquito survival. To determine the number of bites needed to infect a monkey, animals were exposed to various numbers of P. knowlesi-infected mosquitoes. Finally, P. knowlesi-infected mosquitoes were used to challenge 17 monkeys in a malaria vaccine trial, and the effect of number of infectious bites on monkey parasitaemia was documented.ResultsAnopheles dirus, Anopheles crascens, and Anopheles dirus X (a cross between the two species) produced large numbers of P. knowlesi sporozoites. Mosquito survival to day 14, when sporozoites fill the salivary glands, averaged only 32% when donor monkeys had a parasitaemia above 2%. However, when donor monkey parasitaemia was below 2%, mosquitoes survived twice as well and contained ample sporozoites in their salivary glands. Adding methylparaben to sugar solutions did not improve survival of infected mosquitoes. Plasmodium knowlesi was very infectious, with all monkeys developing blood stage infections if one or more infected mosquitoes successfully fed. There was also a dose-response, with monkeys that received higher numbers of infected mosquito bites developing malaria sooner.ConclusionsAnopheles dirus, An. crascens and a cross between these two species all were excellent vectors for P. knowlesi. High donor monkey parasitaemia was associated with poor mosquito survival. A single infected mosquito bite is likely sufficient to infect a monkey with P. knowlesi. It is possible to efficiently challenge large groups of monkeys by mosquito bite, which will be useful for P. knowlesi vaccine studies.

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Section: Discussionmentioning

confidence: 99%

Using infective mosquitoes to challenge monkeys with Plasmodium knowlesi in malaria vaccine studies

Murphy

Weiss

Fryauff

et al. 2014

Malar J

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“…This is in agreement with other previous studies where malaria-related anaemia is more severe in children rather than in adults [79,80] due to increased demand of iron by the body as growth is rapid in children. In 2002, Praba-Egge and her colleagues [81] carried out experimental infection of non-human primates with P. knowlesi and Plasmodium cynomolgi . The study reported that anaemia was observed in P. knowlesi- infected monkeys after primary and/or repeated infection.…”

Section: Discussionmentioning

confidence: 99%

Increased detection of Plasmodium knowlesi in Sandakan division, Sabah as revealed by PlasmoNex™

Goh

Lim

Vythilingam

et al. 2013

Malar J

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BackgroundPlasmodium knowlesi is a simian malaria parasite that is widespread in humans in Malaysian Borneo. However, little is known about the incidence and distribution of this parasite in the Sandakan division, Malaysian Borneo. Therefore, the aim of the present epidemiological study was to investigate the incidence and distribution of P. knowlesi as well as other Plasmodium species in this division based on a most recent developed hexaplex PCR system (PlasmoNex™).MethodsA total of 189 whole blood samples were collected from Telupid Health Clinic, Sabah, Malaysia, from 2008 to 2011. All patients who participated in the study were microscopically malaria positive before recruitment. Complete demographic details and haematological profiles were obtained from 85 patients (13 females and 72 males). Identification of Plasmodium species was conducted using PlasmoNex™ targeting the 18S ssu rRNA gene.ResultsA total of 178 samples were positive for Plasmodium species by using PlasmoNex™. Plasmodium falciparum was identified in 68 samples (38.2%) followed by 64 cases (36.0%) of Plasmodium vivax, 42 (23.6%) cases of P. knowlesi, two (1.1%) cases of Plasmodium malariae and two (1.1%) mixed-species infections (i e, P. vivax/P. falciparum). Thirty-five PlasmoNex™ positive P. knowlesi samples were misdiagnosed as P. malariae by microscopy. Plasmodium knowlesi was detected in all four districts of Sandakan division with the highest incidence in the Kinabatangan district. Thrombocytopaenia and anaemia showed to be the most frequent malaria-associated haematological complications in this study.ConclusionsThe discovery of P. knowlesi in Sandakan division showed that prospective studies on the epidemiological risk factors and transmission dynamics of P. knowlesi in these areas are crucial in order to develop strategies for effective malaria control. The availability of advanced diagnostic tool PlasmoNex™ enhanced the accuracy and accelerated the speed in the diagnosis of malaria.

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“…, see [20; 36; 74; 81; 82; 83; 84; 85; 86; 87; 88]). Because the parasite is threatened by the immune system, it has evolved escape strategies, including the intriguing use of antigenic variation mechanisms [89; 90; 91].…”

Section: Malaria As the Paradigm Infectious Diseasementioning

confidence: 99%

From within host dynamics to the epidemiology of infectious disease: Scientific overview and challenges

Gutiérrez

Galinski

Cantrell

et al. 2015

Mathematical Biosciences

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Since their earliest days, humans have been struggling with infectious diseases. Caused by viruses, bacteria, protozoa, or even higher organisms like worms, these diseases depend critically on numerous intricate interactions between parasites and hosts, and while we have learned much about these interactions, many details are still obscure. It is evident that the combined host-parasite dynamics constitutes a complex system that involves components and processes at multiple scales of time, space, and biological organization. At one end of this hierarchy we know of individual molecules that play crucial roles for the survival of a parasite or for the response and survival of its host. At the other end, one realizes that the spread of infectious diseases by far exceeds specific locales and, due to today's easy travel of hosts carrying a multitude of organisms, can quickly reach global proportions. The community of mathematical modelers has been addressing specific aspects of infectious diseases for a long time. Most of these efforts have focused on one or two select scales of a multi-level disease and used quite different computational approaches. This restriction to a molecular, physiological, or epidemiological level was prudent, as it has produced solid pillars of a foundation from which it might eventually be possible to launch comprehensive, multi-scale modeling efforts that make full use of the recent advances in biology and, in particular, the various high-throughput methodologies accompanying the emerging –omics revolution. This special issue contains contributions from biologists and modelers, most of whom presented and discussed their work at the workshop From within Host Dynamics to the Epidemiology of Infectious Disease, which was held at the Mathematical Biosciences Institute at Ohio State University in April 2014. These contributions highlight some of the forays into a deeper understanding of the dynamics between parasites and their hosts, and the consequences of this dynamics for the spread and treatment of infectious diseases.

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Cytokine responses during acute simian Plasmodium cynomolgi and Plasmodium knowlesi infections.

Cited by 25 publications

References 21 publications

Using infective mosquitoes to challenge monkeys with Plasmodium knowlesi in malaria vaccine studies

Using infective mosquitoes to challenge monkeys with Plasmodium knowlesi in malaria vaccine studies

Increased detection of Plasmodium knowlesi in Sandakan division, Sabah as revealed by PlasmoNex™

From within host dynamics to the epidemiology of infectious disease: Scientific overview and challenges

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