Malaria Research and Control

Thermal biology of mosquito‐borne disease

Mosquito-borne diseases cause a major burden of disease worldwide. The vital rates of these ectothermic vectors and parasites respond strongly and nonlinearly to temperature and therefore to climate change. Here, we review how trait-based approaches can synthesise and mechanistically predict the temperature dependence of transmission across vectors, pathogens, and environments. We present 11 pathogens transmitted by 15 different mosquito species - including globally important diseases like malaria, dengue, and Zika - synthesised from previously published studies. Transmission varied strongly and unimodally with temperature, peaking at 23-29ºC and declining to zero below 9-23ºC and above 32-38ºC. Different traits restricted transmission at low versus high temperatures, and temperature effects on transmission varied by both mosquito and parasite species. Temperate pathogens exhibit broader thermal ranges and cooler thermal minima and optima than tropical pathogens. Among tropical pathogens, malaria and Ross River virus had lower thermal optima (25-26ºC) while dengue and Zika viruses had the highest (29ºC) thermal optima. We expect warming to increase transmission below thermal optima but decrease transmission above optima. Key directions for future work include linking mechanistic models to field transmission, combining temperature effects with control measures, incorporating trait variation and temperature variation, and investigating climate adaptation and migration.

Chikungunya virus: an update on the biology and pathogenesis of this emerging pathogen

Impact of health education intervention on malaria prevention practices among nursing mothers in rural communities in Nigeria

INTRODUCTION: Malaria is the most prevalent parasitic endemic disease in Africa, which is preventable, treatable and curable. This study aims to assess the effect of health education intervention on the knowledge, attitude, and prevention practices amongst mothers of under-five children in a rural area of Ogun State, Nigeria. MATERIALS AND METHODS: The study design was a quasi-experimental study carried out in Ijebu North Local Government Area of Ogun State. A multistage random sampling technique was used in choosing the required samples and a semi-structured questionnaire was used to collect relevant information. A total of 400 respondents were recruited into the study with 200 each in both the experimental and control groups and were followed up for a period of 3 months. RESULTS: There was no statistically significant differences observed between the experimental and control groups. Knowledge of indoor spraying increased from 14.7% to 58.2% (P < 0.001) and window and door nets increased from 48.3% to 74.8% (P < 0.001). The proportion of those with ITN use increased from 50.8% to 87.4% (P < 0.001) while those with practice of maintaining clean environment also increased from 40.4% to 54.5% (P < 0.001). There were no significant changes in all the practice of malaria prevention methods in the control group. CONCLUSION: This suggests that malaria control can be significantly improved in rural areas, if the caregivers are adequately empowered through appropriate health education intervention though change in attitude and belief may require a longer and persistent effort.

Biology of Malaria Parasites

The organism itself was first seen by Lavern on November 6, 1880 at a military hospital in Constantine, Algeria, when he discovered a microgametocyte exflagellating. In 1885, similar organisms were discovered within the blood of birds in Russia. There was brief speculation that birds might be involved in the transmission of malaria; in 1894 Patrick Manson hypothesized that mosquito could transmit malaria. This hypothesis was independently confirmed by the Italian physician Giovanni Battista Grassi working in Italy and the British physician Ronald Ross working in India, both in 1898. [3] Ross demonstrated the existence of Plasmodium in the wall of the midgut and salivary glands of a Culex mosquito using bird species as the vertebrate host. For this discovery he won the Noble Prize in 1902. Grassi showed that human malaria could only be transmitted by Anopheles mosquito. It is worth noting, however, that for some species the vector may not be mosquito.[4]