Ebola Virus Disease Complications as Experienced by Survivors in Sierra Leone

Cannabidiol: a potential treatment for post Ebola syndrome?

Patients recovered from Ebola virus infection may experience short- and long-term physical, neuropsychological and social sequelae, including arthralgia, musculoskeletal pain, ophthalmic inflammation, auditory problems, fatigue, confusion, insomnia, short-term memory impairment, anxiety, depression and anorexia, all lasting from two weeks to more than two years. Currently there are no treatments for post Ebola sequelae. We hypothesize that cannabidiol (CBD) may attenuate some of these post Ebola sequelae, several of which have been postulated to result from inflammation and/or an autoimmune response. CBD has anti-inflammatory actions in various animal models. Clinical studies have shown that oral administration of CBD, compared to placebo, significantly reduces anxiety, has antinociceptive and anticonvulsant actions, and may be therapeutic for insomnia. Overall, CBD has a number of pharmacological effects that may significantly improve the mental and somatic health of patients suffering from post Ebola sequelae. In humans, CBD, at therapeutic doses, does not: 1) elicit dependence or tolerance; 2) significantly alter heart rate or blood pressure; 3) affect gastrointestinal transit; 4) produce significant cognitive or psychomotor impairments. Mild sedation and nausea are the most commonly reported adverse effects associated with CBD.CBD, based on its pharmacological effects and favorable safety profile, should be considered as a treatment for individuals with post Ebola sequelae.

Zika Virus Infection in Mice Causes Panuveitis with Shedding of Virus in Tears

Zika virus (ZIKV) is an emerging flavivirus that causes congenital abnormalities and Guillain-Barré syndrome. ZIKV infection also results in severe eye disease characterized by optic neuritis, chorioretinal atrophy, and blindness in newborns and conjunctivitis and uveitis in adults. We evaluated ZIKV infection of the eye by using recently developed mouse models of pathogenesis. ZIKV-inoculated mice developed conjunctivitis, panuveitis, and infection of the cornea, iris, optic nerve, and ganglion and bipolar cells in the retina. This phenotype was independent of the entry receptors Axl or Mertk, given that Axl(-/-), Mertk(-/-), and Axl(-/-)Mertk(-/-) double knockout mice sustained levels of infection similar to those of control animals. We also detected abundant viral RNA in tears, suggesting that virus might be secreted from lacrimal glands or shed from the cornea. This model provides a foundation for studying ZIKV-induced ocular disease, defining mechanisms of viral persistence, and developing therapeutic approaches for viral infections of the eye.

Rescue of non-human primates from advanced Sudan ebolavirus infection with lipid encapsulated siRNA

Although significant progress has been made in developing therapeutics against Zaire ebolavirus, these therapies do not protect against other Ebola species such as Sudan ebolavirus (SUDV). Here, we describe an RNA interference therapeutic comprising siRNA targeting the SUDV VP35 gene encapsulated in lipid nanoparticle (LNP) technology with increased potency beyond formulations used in TKM-Ebola clinical trials. Twenty-five rhesus monkeys were challenged with a lethal dose of SUDV. Twenty animals received siRNA-LNP beginning at 1, 2, 3, 4 or 5 days post-challenge. VP35-targeting siRNA-LNP treatment resulted in up to 100% survival, even when initiated when fever, viraemia and disease signs were evident. Treatment effectively controlled viral replication, mediating up to 4 log10 reductions after dosing. Mirroring clinical findings, a correlation between high viral loads and fatal outcome was observed, emphasizing the importance of stratifying efficacy according to viral load. In summary, strong survival benefit and rapid control of SUDV replication by VP35-targeting LNP confirm its therapeutic potential in combatting this lethal disease.

Rift Valley fever virus: Unanswered questions

This mosquito-borne pathogen of humans and animals respects no international or geographic boundaries. It is currently found in parts of Africa and the Arabian Peninsula where periodic outbreaks of severe and fatal disease occur, and threatens to spread into other geographic regions. In recent years, modern molecular techniques have led to many breakthroughs deepening our understanding of the mechanisms of RVFV virulence, phylogenetics, and the creation of several next-generation vaccine candidates. Despite tremendous progress in these areas, other challenges remain in RVF disease pathogenesis, the virus life-cycle, and outbreak response preparedness that deserve our attention. Here we discuss and highlight ten key knowledge gaps and challenges in RVFV research. Answers to these key questions may lead to the development of new effective therapeutics and enhanced control strategies for this serious human and veterinary health threat.