Schistosomiasis is a disease caused by parasitic blood flukes of the genus Schistosoma. Species that infect humans are prevalent in developing countries, having a major impact on public health and well-being as well as an impediment to socioeconomic development. More people are infected with Schistosoma haematobium than with all the other schistosome species combined, however mainly due to the inability to maintain S. haematobium in the laboratory system empirical studies on this parasite are minimal. The genetic variation of this Schistosoma species on a wide geographical scale has never been investigated. In this study, we have used a DNA ?barcoding? approach to document the genetic variation and population structure of S. haematobium sampled from 18 countries across Africa and the Indian ocean Islands. The study revealed a distinct genetic separation of S. haematobium from the Indian Ocean Islands and the closely neighbouring coastal regions from S. haematobium found throughout the African mainland, the latter of which exhibited extremely low levels of mitochondrial diversity within and between populations of parasites sampled. The data from this study provides a novel insight into the population genetics of S. haematobium and will have an impact on future research strategies.
DNA vaccines hold promise of overcoming the downsides of traditional vaccinations, potentially allowing for effective defense against HIV and other viral infections. Delivering DNA snippets that code for viral proteins into the insides of cells is a bit tricky and currently requires using electroporation to open pores within cell walls. The technique is not terribly effective and can be painful on the patients. Now researchers from MIT are reporting in Nature Materials the development of a new skin patch, which they like to call a “multilayer tattoo,” capable of delivering DNA vaccines in a more civilized fashion.
The team embedded the vaccine within multiple layers of a polymer film which sits on top of a bed of microneedles that painlessly create a passageway into the body. The polymer film begins degrading once in contact with water and safely releases its cargo.
From the study abstract in Nature Materials:
Films transferred into the skin following brief microneedle application promoted local transfection and controlled the persistence of DNA and adjuvants in the skin from days to weeks, with kinetics determined by the film composition. These ‘multilayer tattoo’ DNA vaccines induced immune responses against a model HIV antigen comparable to electroporation in mice, enhanced memory T-cell generation, and elicited 140-fold higher gene expression in non-human primate skin than intradermal DNA injection, indicating the potential of this strategy for enhancing DNA vaccination.
A news Focus in "Science" delineated past, present and future Schistosomiasis vaccine research, featuring EPLS vaccine candidate "Bilhvax".
"Vaccines would probably not prevent human infections, but they could reduce the number of eggs that female worms produce, which in turn would reduce symptoms and slow transmission, says Maria Yazdanbakhsh of Leiden University Medical Center in the Netherlands, who heads a European project to find a vaccine against S. mansoni. "If the worms produce fewer eggs, the water will be less infested, and that will slowly reduce transmission.""
Mosquitoes are becoming resistant to insecticides used in bed nets and sprays, and malaria parasites are becoming resistant to today’s drugs. New methods for controlling mosquitoes are urgently needed if malaria is to be eradicated.
‘Our genetic modification consists of putting in a gene that codes for the PPO1 enzyme,’ says Crisanti. PPO1 is an enzyme, he explains, that like a shredding machine is able to destroy the X chromosome during gametogenesis, the process by which cells that specialise in sexual reproduction are produced, leaving only the Y, or male chromosome, active. The aim is to produce a predominance of male mosquitoes that cannot therefore transmit malaria.
Chemical ecologist Max Suckling at the Institute for Plant and Food Research Ltd. and summer student Rachael Sagar use Pavlovian conditioning to train bees to stick out their tongues, or proboscises, at the scent of odors produced by tuberculosis-causing bacteria. The researchers hope to one day use the insects to identify TB patients in countries where the disease is common, and where cheap, easy-to-use diagnostic methods are in high demand.
The molecular response of an organism -- be it mouse or man -- to pathogenic invasion is controlled by circadian rhythms, researchers found.
In mice exposed to infection at the highest and lowest time of activity in the 24-hour light-dark cycle of an immune protein known as toll-like receptor 9 (TLR9), those whose exposure was at the nadir of TLR9 expression had much more severe sepsis, according to Erol Fikrig, MD, of Yale University, and colleagues.
In an alarming statistical turn, the number of malaria deaths every year may be vastly underestimated, according to new research re-examining mortality rates from 1980 to 2010.According to a study published in the journal the Lancet, in 2010 there were 1.24 million deaths from malaria worldwide, nearly twice the World Health Organization estimate of 655,000.
"For the third time in seven years, the Sahel region of west Africa is facing a toxic combination of drought, poor harvests and soaring food prices. In Niger, 6m people are now significantly at risk, together with 2.9m in Mali and 700,000 in Mauritania.
An immediate response is needed in order to avert a devastating food and nutrition crisis. In responding, however, we must also redefine the vocabulary of food crisis. It is our global food system that is in crisis. Last year's famine in the Horn of Africa, and the current woes in the Sahel, are the surface cracks of a broken system. These regional outbreaks of hunger are not, as such, extreme events."
"The public sphere has been pumped full of information about how unnecessary use of antibiotics contributes to the development of resistant bacterial strains.The World Health Organization has called antibiotic resistance one of the greatest global health concerns to date."
During the last decades two dams were constructed along the Senegal River. These intensified the practice of agriculture along the river valley basin.
A cross-sectional entomological study was performed in September 2008 in 20 villages of the middle Senegal River valley to evaluate the variations of Anopheles density according to local environment. A longitudinal study was performed, from October 2008 to January 2010, in 5 selected villages, to study seasonal variations of malaria transmission.
A comprehensive new study of the world's health status has the potential to dramatically improve how developing countries address surging problems like noncommunicable diseases, writes CFR's Thomas Bollyky.
Infectious disease and stem cell researchers recently found evidence that tuberculosis bacteria may hide in bone- and cartilage-forming stem cells in bone marrow to protect themselves from drugs and the immune system.
"For some infectious diseases, traditional vaccines just don't cut it. Microbes that hide inside human cells and cause chronic illness aren't stymied by the antibody response generated by the kind of vaccine available at the doctor's office. T-cell vaccines, which activate a different type of immune response, could, in theory, better prevent or control such chronic infections, but so far nobody has been successful at transitioning T-cell vaccines from the lab bench to the clinic."
The smallpox vaccine was the first, and arguably most successful, vaccine ever put into practice, and it was scratched into the skin of individuals. With the invention of syringes and hypodermic needles, vaccination shifted toward administration directly into the muscle, under the assumption that it is better to get a vaccine straight into the body. But it turns out scientists may have had it right the first time.
"The Demographic Surveillance System established in 1962 in Niakhar, Senegal, is the oldest in Africa.
During 1963–2010, infant and under-5 mortality rates decreased from 223‰ to 18‰ and from 485‰ to 41‰, respectively.
Direct and indirect effects of new malaria-control policies, introduced in 2003 and completed during 2006–2008, are likely to have been the key cause of the recent dramatic decrease in child mortality."
"Severe malnourishment of mothers and their children can cause lifelong growth deficiencies and health problems.
But simply providing an adequate food supply likely would not be enough to keep these kids growing well. Researchers said that common childhood incidents in the developing world, such as acute diarrhea and infection with a parasite, compound the problem."
Since 2004 there has been an increased recognition of the importance of Neglected Tropical Diseases (NTDs)as impediments to development. This paper responds to what the authors believe are inappropriate criticisms of these programmes and counters accusations of the motives of partners made in recently published papers.