“The practical implication for malaria control programs is that there is no substitute for careful monitoring of mosquito populations. In order to be effective, such monitoring must be carried out by specialist experts who have the skills to recognise and investigate unexpected entomological observations,” said Lines, who now works with the Malaria Control and Vector Biology program at the London School of Hygiene & Tropical Medicine.
The scientists write in their study, “Cryptic species or subpopulations that exhibit divergent behaviors may be responsible for maintaining malaria parasite transmission, and without adequate discriminatory techniques, these vectors may be misidentified and their key behavioral differences overlooked.”
They are calling for increased surveillance and a focus on integrating a wider range of malaria control tools to deal with the threat of outdoor malaria transmission.
AngloGold Ashanti Limited has targeted 40 districts in the Upper West Region for the Indoor Residual Spraying IRS of mosquitoes under its five-year malaria control project being supported by the Global Fund.The project is being funded with a budget of $133 million in some districts in the Upper West, Upper East, Northern, Central and Ashanti regions.The Upper West Operational Manager of the AngloGold Ashanti Malaria Programme, Mr. Abraham Takorah, said it was expected that a total of 3,800 jobs would be created over a period of five years.He said at a stakeholders meeting at Nadowli that the project had already begun in the Wa Municipality, Wa West and Wa East districts, and would gradually be extended to other areas.The Operational Manager expressed regret that malaria had become a great source of concern, and that despite efforts to fight the disease, it still brings untold havoc to Ghanaians.He, therefore, appealed to people in the beneficiary districts to cooperate with sprayers under the project, by allowing them to spray their rooms when they visit their communities.Mr. Takorah recalled that the project was initially started at Obuasi upon the realisation that there had been a consistent increase in malaria cases at the AngloGold Hospital, with the majority of those affected being workers.He said the project was then initiated and piloted, and within a few months, the cases had drastically reduced.”It was as a result of this that AngloGold, being a good corporate citizen, decided to extend it to other parts of the country, as its social responsibility,” he added.Mr. Takorah commended the Ghana Health Service and other stakeholders for their support and role in combating malaria.
The study, published in the Journal of Antimicrobial Chemotherapy, discovered quinine levels in patients receiving treatment for malaria were linked to the patients’ levels of tryptophan. They were also able to show that the incidence of adverse reaction to quinine was significantly lower in patients with high levels of tryptophan, the study said.
The disappointing outcome was down to the vaccine’s failure to protect against one type of dengue virus, which turned out to be the prevalent one in Thailand at the time of the study.
Overall efficacy was 30.2 percent – statistically insignificant and well below the 70 percent-plus researchers had anticipated at the start of the company-funded trial.
Gulf State mosquito populations are flourishing in pools of stagnant water left in the wake of Isaac. The result is an “inordinate amount of equine deaths attributed to encephalitis,” says Louisiana’s Assistant State Veterinarian Diane Stacy, DVM.
Stacy’s office has been flooded with calls reporting horses with neurologic signs and “downer” horses, which can be clinical signs of West Nile Virus (WNV) and Eastern equine encephalitis (EEE). Both EEE and WNV are spread by mosquitoes.
“As of today (September 11, 2012) we have had 42 confirmed cases of West Nile and 43 confirmed cases of equine encephalitis reported to our office,” said Stacy.
The 43 confirmed cases of EEE in Louisiana are almost double the 26 cases reported by the United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) as of September 4, 2012.
In 2011, there were three confirmed EEE cases and no cases of WNV in Louisiana.
In its study, “Fighting malaria with engineered symbiotic bacteria from vector mosquitoes,” published in the Proceedings of the National Academy of Sciences, the team has focused on a bacterium that lives in the Anopheles mosquito’s mid-gut alongside the malaria-causing parasite, Plasmodium falciparum.
The team made a genetic change in the bacterium (Pantoea agglomerans) that has a symbiotic relationship with the parasite so the bacterium will secrete proteins toxic to the parasite. In rodent studies, the team succeeded in reducing a rodent parasite — a parasite from the same family of Plasmodium parasites as the one that causes malaria — by 98 percent.
Scientists have sequenced the entire genomes of five Plasmodium vivax strains taken from the blood of patients on different continents, providing a wealth of new data to help in the future mapping of malarial parasite traits such as drug resistance, and determine how different strains are geographically distributed. The work, by researchers at Case Western Reserve University and the Cleveland Clinic Lerner Research Institute, has identified over 80,000 SNPs that can form the basis of association studies and population surveys to study the diversity of P. vivax in a single region.
Critically, the results also demonstrate that P. vivax isolates from patients in Madagasar, Cambodia, and South America are genetically surprisingly similar, and exhibit little evidence of local adaptation. One possibility for the relative lack of genetic diversity is that the P. vivax population has only recent origins, and has just dispersed rapidly across the world without major loss of diversity or influence from natural selection. A second possibility for the observed allele sharing, however, is that there’s been a continuous gene flow in the current P. vivax population. “P. vivax is now a cosmopolitan parasite that can be easily spread throughout the world by way of dormant hypnozoites,” the investigators suggest.
“If this second hypothesis is true, it holds bleak prospects for P. vivax malaria elimination,” the researchers add. “With high level of gene flow, genetic polymorphisms conferring drug resistance or novel invasion mechanisms could spread across the world and further complicate control strategies.”