Global & Disaster Medicine

Archive for the ‘Chikungunya’ Category

French officials reported two confirmed local cases of indigenous CHIKV in southern France.

ECDC

“….As of 17 August 2017, France reported two confirmed autochthonous chikungunya cases in the Var district, in southern France. The first case who lives in Cannet-des-Maures in Var district and works in Alpes-Maritimes district had onset of symptoms on 1 August. The diagnostic was confirmed by two PCR tests on 9 an 11 August. The second case, a 67-year-old neighbour of the first case, had onset of symptoms on 8 August and was confirmed on 14 August…..”


A new antibody-based assay distinguishes Zika from similar viral infections

Eureka

“A new test is the best-to-date in differentiating Zika virus infections from infections caused by similar viruses. The antibody-based assay, developed by researchers at UC Berkeley and Humabs BioMed, a private biotechnology company, is a simple, cost-effective way to determine if a person’s infection is from the Zika virus or another virus of the same family, such as dengue and West Nile viruses….”

PNAS

“…..This study demonstrates that the antibody-based assay we developed and implemented in five countries has high specificity and sensitivity in the detection of recent and past ZIKV infections. The ZIKV nonstructural protein 1 (NS1) blockade-of-binding ELISA assay is a simple, robust, and low-cost solution for Zika surveillance programs, seroprevalence studies, and intervention trials in flavivirus-endemic areas….”


A clinical trial of an experimental vaccine to prevent infection with chikungunya virus is now enrolling healthy adult volunteers at three sites in the United States.

NIH

NIAID-Sponsored Trial of Experimental Chikungunya Vaccine Begins

A clinical trial of an experimental vaccine to prevent infection with chikungunya virus is now enrolling healthy adult volunteers at three sites in the United States. The Phase 1/2 trial, which is sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, is being conducted at several NIAID-funded Vaccine and Treatment Evaluation Units. The candidate vaccine, MV-CHIKV, was developed by Themis Bioscience of Vienna, Austria.

Although chikungunya is rarely fatal, the mosquito-transmitted virus causes an intense inflammatory reaction resulting in severe joint pain, fever, rash and muscle pain. While most symptoms usually resolve in days, the joint inflammation can linger.

“Chikungunya virus can cause debilitating joint pain that can last for months or even longer,” said NIAID Director Anthony S. Fauci, M.D. “A vaccine to prevent infection with this virus would be of considerable benefit to people living in the more than 60 countries where chikungunya transmission has occurred, as well as travelers to those countries.”

Chikungunya virus has been endemic in East Africa since at least the 1950s, when it was first discovered. There it circulates among monkeys and, occasionally, humans. The virus likely arrived in the Caribbean in late 2013, and as of March 2017, may have infected more than two million people in the Americas, according to the Pan American Health Organization (PAHO).

A 2014 Phase 1 trial of the MV-CHIKV vaccine conducted in Austria by Themis Bioscience showed that the experimental vaccine was safe and induced an immune response. The candidate vaccine is a measles vaccine virus modified to produce chikungunya virus proteins. Once inside a human cell, the vaccine induces the production of both measles and chikungunya proteins. The immune system then develops antibodies against those proteins, which may protect the vaccinated person from future infection by chikungunya virus.

Led by principal investigator Patricia Winokur, M.D., of the University of Iowa Carver College of Medicine, the new vaccine study will enroll 180 healthy adults ages 18 to 45 at three sites: the University of Iowa in Iowa City; Baylor College of Medicine in Houston; and Emory University in Atlanta. Participants will receive two injections of either low-dose or high-dose experimental vaccine or placebo. Neither the participants nor the investigators will know whether a volunteer is receiving placebo or investigational vaccine. The volunteers will be assigned at random into different groups that receive the two injections at different intervals (29, 85, or 169 days after the initial injection) in order to help the researchers determine which schedule is most effective.

Clinic staff will follow up with study participants by phone and during clinic visits over the course of 8 to 13 months to monitor for any adverse reactions or safety issues. The participants will provide blood samples to be analyzed for evidence of antibody production, which would indicate that the vaccine is prompting an immune response.

Themis Bioscience is currently conducting a Phase 2 trial in Europe with the same vaccine candidate. Other chikungunya vaccine candidates are also under investigation in different trials, including one that uses virus-like particles (VLPs) to induce an immune response in recipients. NIAID sponsored the Phase 1 trial of the VLP vaccine candidate; a Phase 2 trial began in 2015.

For more information about the MV-CHIKV vaccine study, see ClinicalTrials.gov using the identifier NCT03028441.

NIAID conducts and supports research — at NIH, throughout the United States, and worldwide — to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID website.

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

NIH…Turning Discovery Into Health®

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The Pan American Health Organization (PAHO) reported 38,282 new chikungunya cases late last week, an 80% increase in the yearly total.

CIDRAP


edes aegypti mosquitoes that carry Zika can also transmit dengue and chikungunya in the same bite.

Nature

Rückert, C. et al. Impact of simultaneous exposure to arboviruses on infection and transmission by Aedes aegypti mosquitoes. Nat. Commun. 8, 15412 doi: 10.1038/ncomms15412 (2017).

“…..Thus, we here expose Ae. aegypti mosquitoes to chikungunya, dengue-2 or Zika viruses, both individually and as double and triple infections. Our results show that these mosquitoes can be infected with and can transmit all combinations of these viruses simultaneously. Importantly, infection, dissemination and transmission rates in mosquitoes are only mildly affected by coinfection…..”


Countries in the Americas reported 16,436 new chikungunya infections, led almost entirely by new cases in Brazil.

PAHO

Countries with current or previous local transmission of chikungunya virus, listed in below data table

 


The Pan American Health Organization (PAHO) reported 7,342 new chikungunya cases and 5 new related deaths late last week.

CIDRAP

Distribution Map of Chikungunya


PAHO: The total number of chikungunya cases in the Americas grew by 207 after leaping by more than 7,000 cases the week before.

Countries with current or previous local transmission of chikungunya virus, listed in below data table

 


Pakistan’s Ministry of National Health Services, Regulations and Coordination has reported cases of Chikungunya in the country for the first time.

WHO

Chikungunya reported in Pakistan

27 February 2017 – Pakistan’s Ministry of National Health Services, Regulations and Coordination has reported cases of Chikungunya in the country for the first time.

A total of 803 cases have been reported since 19 December 2016 in the Sindh province, including 29 cases reported in various towns in Karachi during the week of 10-16 February 2017. Of the 92 samples sent to the National Instituted of Health for testing, 71 have been laboratory-confirmed postive for Chikungunya virus.

WHO is in close coordination with the Ministry of Health and partners in response efforts. Capacity-building has been conducted and instructions issued to district and town health officers, primary health care providers and hospitals on Chikungunya treatment and preventative measures.

The community has been advised through a door-to-door campaign through the Lady Health Workers programme. Affected areas have been fumigated and high-risk areas have been treated with insecticides using indoor residual spraying.

 


AGS-v: An investigational vaccine that triggers an immune response to mosquito saliva rather than to a specific virus or parasite carried by mosquitoes

NIAID

The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), has launched a Phase 1 clinical trial to test an investigational vaccine intended to provide broad protection against a range of mosquito-transmitted diseases, such as Zika, malaria, West Nile fever and dengue fever, and to hinder the ability of mosquitoes to transmit such infections. The study, which is being conducted at the NIH Clinical Center in Bethesda, Maryland, will examine the experimental vaccine’s safety and ability to generate an immune response.

Mosquito vaccine trial partipant recieves injection

The investigational vaccine, called AGS-v, was developed by the London-based pharmaceutical company SEEK, which has since formed a joint venture with hVIVO in London. The consulting group Halloran has provided regulatory advice to both companies.

Unlike other vaccines targeting specific mosquito-borne diseases, the AGS-v candidate is designed to trigger an immune response to mosquito saliva rather than to a specific virus or parasite carried by mosquitoes. The test vaccine contains four synthetic proteins from mosquito salivary glands. The proteins are designed to induce antibodies in a vaccinated individual and to cause a modified allergic response that can prevent infection when a person is bitten by a disease-carrying mosquito.

“Mosquitoes cause more human disease and death than any other animal,” said NIAID Director Anthony S. Fauci, M.D. “A single vaccine capable of protecting against the scourge of mosquito-borne diseases is a novel concept that, if proven successful, would be a monumental public health advance.”

Led by Matthew J. Memoli, M.D., director of the Clinical Studies Unit in NIAID’s Laboratory of Infectious Diseases, the clinical trial is expected to enroll up to 60 healthy adults ages 18 to 50 years. Participants will be randomly assigned to receive one of three vaccine regimens. The first group will receive two injections of the AGS-v vaccine, 21 days apart. The second group will receive two injections of AGS-v combined with an adjuvant, 21 days apart. The adjuvant is an oil and water mixture commonly added to vaccines to enhance immune responses. The third group will receive two placebo injections of sterile water 21 days apart. Neither the study investigators nor the participants will know who is assigned to each group.

Participants will be asked to return to the clinic twice between vaccinations and twice after the second vaccination to undergo a physical exam and to provide blood samples. Study investigators will examine the blood samples to measure levels of antibodies triggered by vaccination.

Each participant also will return to the Clinical Center approximately 21 days after completing the vaccination schedule to undergo a controlled exposure to biting mosquitoes. The mosquitoes will not be carrying viruses or parasites, so the participants are not at risk of becoming infected with a mosquito-borne disease. Five to 10 female Aedes aegypti mosquitoes from the insectary in NIAID’s Laboratory of Malaria and Vector Research will be put in a feeding device that will be placed on each participant’s arm for 20 minutes. The mosquitoes will bite the participants’ arms through the netting on the feeding devices.

Afterward, investigators will take blood samples from each participant at various time points to see if participants experience a modified response to the mosquito bites as a result of AGS-v vaccination.

Investigators also will examine the mosquitoes after the feeding to assess any changes to their life cycle. Scientists suspect that the mosquitoes who take a blood meal from ASG-v-vaccinated participants may have altered behavior that could lead to early death or a reduced ability to reproduce. This would indicate that the experimental vaccine could also hinder disease transmission by controlling the mosquito population.

All participants will be asked to return to the clinic for follow-up visits every 60 days for five months following the mosquito feeding. A final clinic visit to assess long-term safety will take place approximately 10 months after the mosquito feeding. Throughout the trial, an independent Data and Safety Monitoring Board will review study data to evaluate participant safety and the overall conduct of the study. A medical monitor from NIAID’s Office of Clinical Research Policy and Regulatory Operations will also perform routine safety assessments.

The study is expected to be completed by summer 2018. For more information about the trial, see ClinicalTrials.gov using the trial identifier NCT03055000 (link is external).


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