Breakthroughs Blog: Zika

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. A new tool developed by the University of Greenwich uses hot water and human scent to lure and trap mosquitoes. The tool is a simple black bucket attached to a wind tunnel that blows warm air with a human scent. The mosquitoes, initially attracted to the scent, are lured to the bucket, and then use the thermal indicators of the warm water to land. The bucket itself is covered in a sticky plastic that traps the mosquitoes. This tool is inexpensive, easy to build, and has proven to be effective in trapping large amounts of the insect. The developers are testing the prototype in three African nations and believe the tool could be a breakthrough in reducing mosquito-borne diseases. Pew Charitable Trusts has announced it will create a new cloud-based digital platform to allow researchers to share data and collaborate to discover new antibiotics to tackle antimicrobial resistance (AMR). As AMR levels continue to rise across the globe, scientists are moving quickly to discover new antibiotics that can treat resistant strains of viruses and bacteria. The platform will host a “virtual laboratory” for scientists to collaborate and crowdsource information to break through common obstacles and limitations associated with discovering new antibiotics. The system is expected to launch within a year. Antibiotic use in Chinese factory farms is expected to double by 2030, causing concern in the science community. Because more than half of the antibiotics used globally are used in China, scientists are worried that increased use in the poultry industry could accelerate the growth of antimicrobial resistance. Researchers are also concerned the industry practices have made avian flu an increasing global threat. The global livestock industry has been under scrutiny for years following a major dirty meat scandal involving major fast food chains, highlighting continued issues with the worldwide impact of food supply chains. Scientists urge changes to make livestock healthier, reduce greenhouse gases, and track the global movement of meat.

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.

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. The World Health Organization (WHO) and UNICEF have reported nearly 1 in 10 children did not receive any immunizations in 2016. This includes immunizations for diphtheria-tetanus-pertussis (DTP). WHO and UNICEF reported that the global immunization rate for the full round of the DTP vaccine is only 86 percent, falling short of the 90 percent goal of global immunization. Furthermore, in 2016, eight countries had DTP immunization rates of less than 50 percent. Estimates by WHO and UNICEF suggest that 10 million more children in 64 countries need to be vaccinated every year in order to achieve the 90 percent goal. This highlights the need to bring vaccines to low-resource settings that have been chronically affected by low immunization rates. A new study published in Proceedings of the National Academy of Sciences highlights a new diagnostic tool that performed well in distinguishing Zika from other flaviviruses, including dengue. UC Berkeley and Humabs BioMed partnered to create a low-cost, easy-to-use diagnostic tool to specifically test for the Zika virus. Researchers found this tool was capable of distinguishing between Zika and other flaviviruses, as well as distinguishing current and past Zika infections in patients. The tool had 91.8 percent sensitivity—the ability to correctly identify those with the disease—and 95.9 percent specificity—the ability to correctly identify those without the disease. This tool could be used in Zika- and dengue-endemic areas, assisting in diagnostic processes and subsequent treatment, especially among populations adversely affected by Zika, like pregnant women. For the first time in history, more than half of all HIV-infected individuals are receiving treatment. In 2016, it was estimated that 19.5 million individuals were receiving HIV treatment, with a total of 36.7 million people infected with HIV. These estimates are both increases from the estimated 17.1 million treated and 36.1 infected in 2015. Further, AIDS-related deaths have decreased by more than half since 2005. Though these rates are promising in the fight against the global epidemic, the United Nations (UN) acknowledges that there is much left to do in the fight against HIV and AIDS, particularly in the context of less stable health systems in resource poor settings.  

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. A recent Congressional hearing on Zika has revealed that there is a lack of consensus regarding the diagnosis and treatment of the virus. Furthermore, only approximately 25 percent of babies born from women who have been exposed to Zika receive the necessary follow-up to evaluate their children for developmental defects. Such follow-up is critical—Zika can cause defects in the infant months after birth. As a result, the impact of Zika may be underestimated, leaving public health professionals uneasy about proposed budget cuts by the Trump Administration, which could exacerbate the treatment and reporting challenges that characterize the current outbreak. Chagas disease, colloquially known as "kissing bug disease," is more deadly than previously thought due to underreporting of the disease. Going undiagnosed while carrying Chagas can elevate the risk of death, primarily due to associated heart problems that will develop over time. Chagas disease initially mimics symptoms of the flu, often causing a misdiagnosis and lack of proper treatment, and it can lie symptomatically dormant for years, silently causing irreparable damage to the heart. There is currently no effective vaccine against the disease. The Democratic Republic of Congo’s (DRC) Ministry of Health has approved the use of an experimental Ebola vaccine to combat the outbreak. The vaccine, though experimental, proved to be highly effective in clinical trials. Details of how the vaccine will be deployed have not been announced yet, but if further cases are confirmed, it will likely be given to contacts and contacts of contacts of those with a confirmed case. So far, there have only been two confirmed cases, but over fifty suspected cases.