Indo-U.S. Workshop on Challenges of Emerging Infections and Global Health Safety Summary of a Workshop (2016) / Chapter Skim
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2 Human Health
2 Human Health
Pages 33-62
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From page 33... ...
Aquatic birds are believed to be the reservoir for these viruses, because all of these HA and NA subtypes, with the exception of the bat influenza viruses, have been found in aquatic birds. These viruses have crossed over to mammalian hosts and avian hosts, primarily terrestrial poultry, as well as to humans.
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From page 34... ...
Reassortment involves two distinct viruses infecting a single cell, with the resulting progeny having swapped gene segments. Unfortunately, this is a common occurrence in influenza viruses and something that contributes to the pathway of transmissibility from animals to humans.
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From page 35... ...
In 2012, there were more than 200 cases of an H3N2 swine variant virus, which resulted in many human infections, primarily in young children that were visiting agricultural fairs who came into close contact with pigs. Subsequently, due to public health messaging, the number of human cases of swine influenza has declined in the past 2 years.
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From page 36... ...
Historical overview of swine influenza virus circulation in pigs and detection of human infections. SOURCE: Todd Davis, presentation at the workshop.
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From page 37... ...
2 In the context of the increase of human cases, there were also genetic mutations identified in the hemagglutinin gene of these viruses, two of which were associated with increased transmissibility in a ferret model. These two particular mutations have been described by both Ron Fouchier's lab and Yoshi Kawaoka's lab as being important for the aerosol transmissibility of influenza viruses in a ferret model.
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From page 38... ...
Davis spent several weeks in Cambodia to try to understand the scope of this potential problem and then to conduct risk assessments, both in Cambodia and in Atlanta. They started by looking at the specific mutations in the hemagglutinin genes of H5N1 viruses that were detected in Cambodia.
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From page 39... ...
They were particularly interested in knowing if any of the mutations had been detected in poultry or in environmental samples that had been collected in 2013. It became apparent from the beginning that these mutations were restricted only to human infections of H5N1.
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From page 40... ...
They used much of this molecular data to inform additional studies and additional characterization of influenza viruses as a means of understanding how they behave antigenically. A large part of what Davis's lab does at CDC is to understand how well a vaccine might cover a specific virus.
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From page 41... ...
enhanced laboratory for the highly pathogenic viruses, in particular, but also for any exotic lowpathogenic avian influenza viruses or other exotic animal influenza viruses. All of the initial work, even the extraction of virus RNA, is performed in a BSL-3 enhanced laboratory.
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From page 42... ...
The Influenza Division of CDC is working to try to improve their advanced molecular detection of viruses from clinical specimens so that they can avoid some of the additional isolation and propagation that occurs in the BSL-3 enhanced laboratory. Finally, vaccine development for zoonotic influenza viruses involves the use of recombinant DNA in research, which is overseen by CDC's Institutional Biosafety Committee, and animal studies may also involve review and approval by the National Institutes of Health's Institutional Animal Care and Use Committee.
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From page 43... ...
Another participant asked if there are patents protecting the sale of viruses based on the reverse genetic method used. Davis replied that these methods are all used within a research environment.
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From page 44... ...
Margaret Chan, who said, "Today collaboration to achieve public health goals is no longer simply an asset. It is critical necessity." 4 There are 11 countries in WHO's South East Asia region, which has six percent of the world's land area, 25 percent of the population, and approximately 30 percent of the communicable disease burden.
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From page 45... ...
• Money Shah continued by pointing out several major issues in health laboratories in the South East Asia region that prevent labs from meeting the 11 criteria. There is limited public health laboratory capacity, which varies from country to country, and not all member states have laboratory policy plans, focal points, or national frameworks for health labs.
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From page 46... ...
Designated biosafety officers are also rare, biosafety guidelines are often either not available or poorly implemented, and regular safety inspections and waste management programs are few. Mandatory immunizations for lab personnel are insufficient, and occupational health and medical surveillance programs are rarely mandatory.
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From page 47... ...
on PPE. Training also includes biological waste management, good laboratory practices, and infection prevention and control guidelines.
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PERSPECTIVES ON THE WEST AFRICAN EBOLA OUTBREAK Ksiazek recounted the 6-week trip he took to Sierra Leone at the invitation of CDC in August 2014. He provided some of his personal perspectives on the outbreak in Guinea, Liberia, and Sierra Leone, and described the history of the Ebola outbreak and the filoviruses within Africa (see Figure 2-5)
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From page 49... ...
In contrast, the 1995 Kikwit outbreak had been ongoing for only a month or so by the time infectious disease experts arrived, so there was an opportunity to observe transmission in the midst of the outbreak. The isolation facility parameters for operating safely with Ebola patients were established during the 1995 Kikwit outbreak; and control measures for health care workers were also established over the course of the outbreak.
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From page 50... ...
If this can happen thoroughly and rigorously, an outbreak can be stopped. Household quarantine, in contrast, is not an effective means of infection control.
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From page 51... ...
Burials were a significant contributing factor in the West African outbreak, and are a critical source of infection. Specifically, after patients die they are often buried by their families in a manner that poses high risk for transmission.
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From page 52... ...
Because existing tracking methods were designed to deal with smaller, more limited outbreaks, 5 For information on the death toll of the 2014 Ebola outbreak in West Africa, see the U.S. Centers for Disease Control and Prevention: http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/case-counts.html; accessed April 10, 2016.
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From page 53... ...
One modification was to convert the program from a single-user application, one that could be used on a single laptop, into a sequel server version outfitted with Wi-Fi routers so that multiple people could enter data from multiple laptops onto a single server version. Another necessary modification was to devise a means by which data from individual regional or local databases could be uploaded into a national database to obtain national statistics.
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From page 54... ...
Unfortunately, in the majority of facilities, infection of healthcare workers was quite common. Ksiazek did not believe that this was due to a lack of PPE per se, but rather that healthcare workers felt at risk and the number of infections supported that belief.
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From page 55... ...
Downward trends in infection rates, Ksiazek suggested, were largely due to a change in people's behavior. By the time Ksiazek departed in late September 2014, officers had been placed in a number of other districts where transmission had begun to pick up, in an effort to forestall infection.
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From page 56... ...
Discussion The discussion following Ksiazek's presentation focused on questions about the source and prevalence of the outbreak, including the role of sequencing, transport of samples, and WHO data. Using Sequencing to Determine the Origin of Outbreaks A participant asked Ksiazek about one theory regarding the original case in Guinea, that one child and his mother ate infected bat meat.
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From page 57... ...
Discrepancies in WHO Data A participant asked about the missing set of cases on the graph that Ksiazek presented (Figure 2-8)
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From page 58... ...
THE EBOLA CONTROL STRATEGY IN INDIA Ratnakar Sahoo focused his presentation on some of the measures the Indian government took to identify and isolate suspected cases of Ebola entering India. He began by recounting that as of the date of the workshop, there were six or seven suspected cases in India.
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From page 59... ...
Other BSL-3 labs across India have also been strengthened to handle potential Ebola cases. Indian experts are concerned about a potential outbreak of Ebola in India because there are nearly 45,000 Indians now living in West Africa.
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These central teams are comprised of a physician and a microbiologist. Doctors, nurses, and others at designated hospitals have been provided with infection control training and full body protection to deal with Ebola cases, should they arrive.
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Human Health 61 FIGURE 2-10 Proposed conceptual layout plan of isolation ward and rooms for Ebola in existing premises. SOURCE: Ratnakar Sahoo, presentation at the workshop.
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From page 62... ...
Sahoo replied that if symptoms are seen and the person is arriving from an affected area, they are categorized as high-risk, as are those suspected of having a history of travel to an affected area or close contact with someone who had symptoms of the Ebola virus.
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