Track topics on Twitter Track topics that are important to you
Isolated minority communities in China use traditional plant-based methods of mosquito control. This study is evaluating 4 plants used in this way by monitoring mosquitoes entering houses on nights when the plants are being used in this way. A blind, placebo controlled study design will monitor plant use and record mosquito species / numbers caught in CDC light traps indoors over 3 months.
One of the greatest challenges to those planning vector control programmes in developing Countries is the provision of cover to those populations in remote or isolated areas. Commonly, it is these communities which bear the greatest burden of disease due to location and inaccessibility to local health care. Yunnan Province is a good example of such problems. The border region with Laos, Myanmar and Vietnam contributes a high proportion of all malaria cases in the whole of China, yet few if any disease control initiatives cover the rural minority peoples and migrant workers who inhabit the region. Comprehensive ethnobotanical surveys in the area have shown many of the 25 minority peoples living in isolated communities already use traditional herbal forms of mosquito control utilising several of the abundant species in the particularly diverse local environment. Having identified a number of potentially useful plant species being used, in terms of their availability, sustainability, low cost (free) and known chemical constituents, the investigators and the local Chinese malaria control officials consider a phase II evaluation of the most promising candidates is justified. In particular, 4 widely used plants are traditionally used as fumigants to reduce / prevent mosquitoes entering houses, either by burning dried or fresh material on the indoor cooking fires each evening, or by spraying tinctures around entry sites like eaves & windows. Due to the method of use, it would be very difficult to simulate this in the laboratory, so a simple means of field evaluation has been chosen.
The ethnobotanical survey revealed the following plant species as candidates for further study; Artemesia argyi, Eucalyptus robusta, Eupatorium odoratum, Cinnamomum glanduliferum
Each of these plant species occurs naturally in abundance in the region and collection will have no significant environmental impact. Moderate amounts (approx 1 Kg) sufficient for each study will be collected locally in each field site prior to (if used dried) or at the start of each experiment (fresh).
Plants will be evaluated under natural user conditions in a randomised and controlled manner in villages in Xishuangbanna Region, Yunnan, PR China. Village- based studies of several other mosquito control methods have already been successfully undertaken in this region by the LSHTM and YIPD team. Villages belonging to one of the ethnic groups using each traditional method will be selected according to agreement between local health workers from YIPD and the village elders, availability of plant species, and preliminary survey of vector species collected indoors with CDC traps. A different village will be selected for each plant being evaluated. After collecting background entomological data, 6 houses matched for baseline parameters (such as occupancy level, location, construction & animal proximity) and being evenly spaced among others in the village (to reduce diversion effects) will be enrolled into the study. On any one night, 2 will be allocated treatment (use of plant), 2 will be allocated hay (used for cattle bedding) as a negative control, and 2 will be left unused (to reduce any residual effects). In each case the treatment or control group will be instructed to place pre-prepared batches of plant material (weighed fresh or dry depending upon type) onto their cooking fire in the traditional manner in the early evening. Commercial CDC traps (BioQuip Inc., USA) will be used in / beside the sleeping areas of each house from 1 hour before sunset to early morning. Catches will be identified by local vector experts each day to record species and number. House treatment will be rotated each night using latin square principles to achieve a minimum of 12 replicates of each treatment in every house (36 nights duration, 216 trap/nights), and will take place during the rainy (malaria) season (July – Nov 2005) when both plants and vector levels are highest.
In the case of C. glanduliferum, the plant extract (or hay extract) will be sprayed at a predetermined rate onto eaves & doors / windows in the traditional manner following the same principles. Efficacy will be determined by comparing mosquito species / numbers caught in control & treatment houses using appropriate statistical analysis & ANOVA methodologies.
Allocation: Randomized, Control: Placebo Control, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind, Primary Purpose: Prevention
anti-mosquito plant use
Yunnun Institute of Parasitic diseases
Gates Malaria Partnership
Published on BioPortfolio: 2014-08-27T03:53:05-0400
This is a study of the genetics of malaria transmission by the mosquito vector in Africa, Anopheles gambiae. The study focuses on the mosquito vector, not the human subjects infected with ...
The combined use of a mosquito repellent and long lasting insecticidal nets (LLINs) by household members would result in a 40% reduction in malaria prevalence compared with households that...
Although mosquito coils are widely used, there is no robust evidence that their use can provide clinical reduction in malaria. This study will randomise 4 groups of 400 houses, each with...
The purpose of this study is to determine how many infected mosquito bites are required to reliably give volunteers a case of malaria. It is expected that volunteers will develop malaria a...
In Cambodia, falciparum is becoming more difficult to treat because drugs are becoming less effective. The investigators can help to try to prevent the spread of this resistant malaria by ...
Plasmodium falciparum gametocytes are essential for malaria transmission. Malaria control measures that aim at reducing transmission require an accurate characterization of the human infectious res...
Mosquito-based malaria transmission-blocking vaccines (mTBVs) target midgut-surface antigens of the Plasmodium parasite's obligate vector, the Anopheles mosquito. The alanyl aminopeptidase N (AnAPN1) ...
Numerous plants with insect repelling properties are native to the tropics where they are produced for a wide range of medicinal purposes. In Thailand, these native plant species have a history of use...
Aedes aegypti and Anopheles gambiae are two mosquito species that represent significant threats to global public health as vectors of Dengue virus and malaria parasites, respectively. Although mosquit...
The development of differentiated sexual stages (gametocytes) within human red blood cells is essential for the propagation of the malaria parasite, since only mature gametocytes will survive in the m...
A protozoan parasite that causes avian malaria (MALARIA, AVIAN), primarily in chickens, and is transmitted by the Aedes mosquito.
A protozoan disease caused in humans by four species of the PLASMODIUM genus: PLASMODIUM FALCIPARUM; PLASMODIUM VIVAX; PLASMODIUM OVALE; and PLASMODIUM MALARIAE; and transmitted by the bite of an infected female mosquito of the genus ANOPHELES. Malaria is endemic in parts of Asia, Africa, Central and South America, Oceania, and certain Caribbean islands. It is characterized by extreme exhaustion associated with paroxysms of high FEVER; SWEATING; shaking CHILLS; and ANEMIA. Malaria in ANIMALS is caused by other species of plasmodia.
A species of mosquito in the genus Anopheles and the principle vector of MALARIA in Africa.
Malaria caused by PLASMODIUM VIVAX. This form of malaria is less severe than MALARIA, FALCIPARUM, but there is a higher probability for relapses to occur. Febrile paroxysms often occur every other day.
Vaccines made from antigens arising from any of the four strains of Plasmodium which cause malaria in humans, or from P. berghei which causes malaria in rodents.
Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...
Malaria is a serious tropical disease spread by mosquitoes. If malaria is not diagnosed and treated promptly, it can be fatal. What causes malaria? Malaria is caused by a type of parasite known as Plasmodium. There are many different types of Plasmod...