August 06, 2017

Research Roundup: Next generation technologies for vector control, tracking Zika, and treating resistant TB

Program Assistant
PATH/Mike Wang

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.