Research Roundup: Mosquito traps and the impact of antibiotics

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. Scientists at the UK’s John Innes Centre believe that a plant closely related to tobacco may hold promise in accelerating polio eradication by transforming vaccine manufacturing. Scientists have hijacked the plant’s growing mechanisms with genetic code for making the outer surface of poliovirus and taught them to grow virus-like particles, which are then extracted into a vaccine. This resulting vaccine mimics the poliovirus, and thus elicits an immune response, but contains none of the properties that cause a poliovirus infection. Scientists are hopeful this may be an effective way to create safe vaccines in the future that aren't made with live viruses, and hope to mimic the process with other viruses as well. Following the 2014 Ebola outbreak in several African countries, an African Centers for Disease Control and Prevention (Africa CDC) was formalized and launched to focus on capacity building in Africa to protect against infectious disease threats. Ending malaria is an important target of the Africa CDC, but there is much to be done to achieve this goal. First, efforts to collect real-time data must be strengthened to ensure the Africa CDC makes informed decisions. Second, international aid institutions and African nations must provide adequate resources to support the Africa CDC. Third, the international community must continue to work toward malaria eradication. Scientists believe individuals in the Americas have developed herd immunity that has resulted in a significant drop-off in Zika incidence. Once a person is infected with Zika, it is not possible for them to be infected again, so they can no longer pass on the virus to mosquitoes who pass it on to other individuals. Scientists think because Zika is usually asymptomatic in non-pregnant individuals, many have been infected and are now immune. This suggests that as the number of people resistant to the virus increases, incidence of others contracting the virus will decrease. With that said, however, scientists still urge pregnant women to take caution when traveling to Zika endemic areas of the world.

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. Scientists at the National Institutes of Health’s National Institute of Allergy and Infectious Diseases have developed a Zika transmission model using mice in order to model the virus’ transmission from human-to-human. While humans are naturally more susceptible to contracting Zika than mice are, scientists were able to use genetically modified mice to validly mimic the transmission. Scientists found that while vertical transmission is possible from mother to fetus, some of the fetuses were not infected with the disease, suggesting the placenta is capable of being an effective barrier to the disease. They also found that Zika can be found in the lymph nodes, suggesting the virus can infect more areas of the body than previously thought. The World Health Organization has provisionally recommended the use of a new insecticide bed net, the Interceptor G2, which is capable of killing up to 75 percent of mosquitos that have become resistant to a common insecticide. The Interceptor G2 bed net combines two different insecticides: pyrethroid, which is currently used in insecticide-treated nets, and chlorfenapyr, an insecticide previously only used in agricultural settings. Studies in sub-Saharan Africa have yielded promising outcomes, with the nets remaining effective even after having been washing up to 20 times. Three studies recently published in Emerging Infectious Diseases found new treatments against multidrug resistant (MDR) and extensively drug resistant (XDR) tuberculosis (TB) are delivering positive results. The largest study focused on a year-long delamanid treatment for 53 MDR-TB patients. Following treatment, 73.6 percent had a favorable response, with 67.6 percent of participants having multiple negative TB cultures. The second study analyzed bedaquiline therapy on 27 children with both MDR- and XDR-TB, and found that of the 23 children that remained a part of the study over the year, all had negative cultures. The third study was retroactive, with researchers observing combined bedaquiline and delamanid therapies in XDR-TB patients. In a total of five participants, researchers found one was culture negative, three were continuing treatment, and one had died. While these studies all have small sample sizes, preliminary data suggests these drugs have a high efficacy in treating resistant strains of TB.