key: cord-0008023-949i2af4 authors: McFee, Robin B. title: SELECTED EPIDEMICS & EMERGING PATHOGENS date: 2017-09-12 journal: Dis Mon DOI: 10.1016/j.disamonth.2017.03.015 sha: 7a392c421889d1be81ca1208332f288570d6578c doc_id: 8023 cord_uid: 949i2af4 nan Newly identified, reemerging or more virulent strains of more commonly identified pathogens have occurred, such as the pandemic avian influenza also referred to as highly pathogenic avian influenza HPAI H5N1, or the latest to be reported from China -Influenza H7N9. Severe acute respiratory syndrome (SARS) coronavirus from 2003 demonstrated that a previously considered low acuity pathogen could emerge in a more deadly form; this is underscored by the most recent and more deadly coronavirus -Middle East Respiratory Syndrome coronavirus (MERS CoV), which will be discussed later in this issue. Moreover infectious diseases previously considered controlled, such as pertusis, even varicella (Image 1) measles (Image 2) and mumps, have reemerged, in no small measure to the anti-vaccine movement that remains a strong voice in contemporary society, and a challenge for health care providers, as well as dangerous to public health preventive measures. Consider the dynamic interplay between basic reproductive rates (Ro) for pathogens and the percent of the population that must be immunized to control illness [50] . Ro is representative of the contagion potential, the human to human communicability, or the average number of persons who become infected by a single source. Put another way, it represents secondary transmission from one case. For example the transmission rate of Measles (Ro) is estimated at 12 -18, i.e. the number of persons expected to become sick after contact with that one infected patient. Pertusis, another respiratory pathogen has caused local outbreaks, sharing a similar Ro with Measles of 12 -17. To optimize herd immunity, a community must have at between 83 -94% vaccinated against measles, and 92 -94% vaccinated against Pertusis, to limit spread. Although some have suggested the Ro of measles to be less in the post vaccination era for developing countries, the fact remains that it is still a highly contagious pathogen, and requires continued high vaccine rates for effective control. Developing countries continue to have lower than necessary vaccine rates; travelers from such regions can therefore pose a health risk if infected. [50] Other contributors to communicable disease spread include inability to adequately control vectorsespecially mosquitoes and ticks which have expanded their regions of influence, and with that, the ability to spread a variety of pathogens. Of note US mosquitoes are more than capable of spreading Dengue (Image 3), and other dangerous microbes. Notably if cases are identified in a region, they pose a threat as a source for mosquitoes to further spread the infection. Clearly contributing to infection spread is overcrowdingfrom poverty where many persons live in close quarters, to public transportation which increasingly is overburdened, to emergency departments that more often than not fail to provide space for social distancing, e.g. cohorting/isolating potentially contagious patients. A recent visit to a medical center revealed how suboptimal are efforts at infection control, where hand sanitizers, masks and instructions on basic hygiene practices were difficult to find, and when available, poorly placed. Clearly there is a need to develop the culture of infection control. Cohorting contagious patients from injured or non-infectious persons should not be a Herculean task in 21 st century healthcare. Can we not do better than inadequately following up with persons ill with pathogens that if undertreated, could lead to antimicrobial resistance as well as outbreaks in an era of computerization? Lack of resources to clean hospital rooms, and other health care facility associated issues such as catheters, test equipment, curtain/bed contamination, and antimicrobial resistance all contribute to infection spread. According to the Centers for Disease Control and Prevention (CDC) 1 in 25 hospitalized patients has a healthcare-associated infection [24] . Additional low hanging fruit, which is not to say barriers don't exist to improvement, include good environmental and infection control practices remain inconsistent across departments, and facilities; hospital acquired infection rates, and delayed diagnosis rates of travel associated illness are testament to the learning curve and challenges we face. More research is needed into how best to cohort patients, the use of quarantine and isolation, along with more efficient ways of implementing these if necessary. Working with facilities and other managementnursing, infectious disease, administrators -we can create less infection friendly environments from the emergency department to the hospital room, and testing sites within the facility. Another area of concern that all health care providers can make an important contribution is vaccination rates. They are not universal across the populations within our midst. This is supported by government studies, and well described in a recent report from the Trust for America's Health (TFAH) [58], a nonpartisan, nonprofit research enterprise. They recently published a study designed to assess the performance of 50 states and Washington, DC based upon 10 indicators that relate to the treatment/prevention of infectious diseases (including HIV, influenza, and pertusis). TFAH relied upon publicly available and government data to examine the emergence and reemergence of specific infectious diseases. The results are not inspiring. Based on a scale of 1 to 10with 10 being the highest positive rankingthe majority of states earned a score of 5 or lower. New Hampshire earned the highest score -8. Georgia, Nebraska and New Jersey were ranked at the bottom with a score of 3. Of additional concern, more than 2 million American children under 3 years of age do not receive all of the vaccinations recommended by the Department of Health and Human Services, and at risk for whooping cough and measles. Not surprisingly both illnesses have reemerged in the last few years. Not to put too fine a point on this, but according to the TFAH study, only two states -Connecticut and Delaware -met the recommended requirement of fully vaccinating 90 percent of children ages 19 months to 35 months. As an aside, years ago my colleagues and I started a church based flu shot clinic; often providing 100 free influenza vaccinations at the event; with a congregation of 125 that's not insignificant, especially given the remaining persons received their vaccines elsewhere. Each recipient also received a vaccine card for their medical records. Non-traditional, community based approaches to healthcare have continued to increase throughout the US, and can be utilized to increase surveillance and provide vaccines, as well as front line care. These will be needed as public health resources continue to dwindle. Critical of course is interconnecting these enterprises so that in the process of increasing access, we don't create multiple isolated islands. Throughout history, faith based enterprises have been good places to reach often at risk populations. Schools and other community enterprises are important points of contact. HCPs are noted for resourcefulness, and this is nowhere needed more than in encouraging, and increasing immunizations for adults and children, especially as pertain to respiratory and other communicable pathogens that include but not limited to influenza and pneumonia to pertusis and hepatitis. An entire edition of Disease a Month could be devoted to immunizationswhat are needed, what are in development, what we have, and how effective at delivery for adults, children, and immigrants. Let it suffice, there is room for improvement in providing the vaccines we do have while encouraging development of those we need to address emerging pathogens. An introduction on epidemics and emerging pathogens would be incomplete without a discussion of travel associated illnesses (TAI) which is an important conduit between diseases found overseas and the people who can become exposed by travelling to areas of illnesses endemic to their location but perhaps not found in the US, and therefore may be unfamiliar to our health care providers. Not only does this pertain to immigrants, vacationers, and business travelers, but also our returning military. Servicemen and women are tasked with working in a variety of inhospitable and dangerous regions with endemic illnesses not typically found in the United States, such as malaria, Physicians can be an important source of counseling about pre-vacation or pre-business travel health concernsfrom specific information about local travel clinics which are becoming increasingly prevalent in urban centers, to infection and vector risks, to safety, and health resources to guiding patients towards CDC, and CIA sites [51, 52] . The importance of our effortswhich can be accomplished by placards and chart promptscannot be underestimated. A recent study of tourists visiting a national park in the United States Virgin Islands where mosquito borne illnesses, including Chikungunya virus are present, revealed most visitors surveyed did not research destination related health concerns and were unaware that Chikungunya virus was present or problematic [53] . This is similar to other studies where travelers did not access pre-trip health information sources, many of which are readily available on the Internet [53] [54] [55] [56] [57] . A more in depth discussion of TAI is in the Prevention Section of this edition. In addition to well established pathogens within the US, the rising numbers of immigrants from regions that typically don't enjoy the same robust public health services, availability of vaccines, or good medical care, pose a threat of contagion from communicable diseases long since controlled, or not typically encountered in the United States, such as multidrug resistant tuberculosis (MDR TB). According to the CDC approximately 80,000 refugees and 500,000 immigrants come to the United States from around the globe [17, 24] . Immigration demographics have changed over the years, and in the aftermath of war torn regions, have invited refugees from the Middle East and Africa, in addition to Mexico, and South America. Each region is nuanced in terms of pathogens that pose a communicable risk, as well as causing illnesses such as food borne diseases that may be initially misdiagnosed or attributed to more localized pathogens. Even the limited belongings can transport pathogens and insects [17] . Related to immigration is the concept of population mobilitywhich may increase the potential for establishing transmission of new infections-as seen with dengue and Chikungunya fever -in areas where vector mosquitoes preexisted but did not prior to these changing demographics spread such infections. Immigrants have ongoing links with populations in their countries of origin that may provide a channel through which infectious diseases potentially can be introduced to new areas. This is consistent with epidemiology data. The CDC Emerging and Zoonotic Infectious Disease Initiative budget request outline notes that Chikungunya Virus is emerging to the point where over 900,000 suspected cases reported since the first local transmission in the Western Hemisphere was noted in 2013. An important subgroup of immigrants involves children, as refugees, immigrants, or having been adoptedmany of whom are not vaccinated for communicable diseases such as polio, chicken pox (Varicella -Image 1), and measles (Image 2). As noted in the mass migration of children to the US Southern border a few years ago, scabies and lice were also problematic, and can cause significant challenges to treating as well as housing facilities, hospitals, and providers' offices. In the December 2013 Disease a Month issue [25] we discussed the threat of multiple global infectious diseasesand the possibility that many of the illnesses described typically located in distant lands could and would emerge in the United States. This included an in depth look at the viral hemorrhagic fever virus (VHF) Dengue, with an overview of VHFs that could pose a threat, including Ebola. If any benefit can be attributed to the Ebola epidemic of 2013 -2016 it may be the increased sensitization of our health care professionals, including emergency departments, referable to travel related disease, occupational exposures and emerging threats. The increase in face masks, instructions to patients who might be infected with a contagion, and attempts at isolating such persons, are important steps towards limiting outbreaks. One important VHF -Ebola demonstrated in the outbreak of 2013 through 2016 how historically stable patterns of outbreaks can change, and what was once considered an isolated, regional pathogen can become widespread. Ebola taught us to expect changes in outbreak patterns. Previous to the Ebola Virus (EV) 2013 -2016 outbreak involving thousands of persons infected, most EV outbreaks involving this viral hemorrhagic fever virus resulted in very limited numbers of patients. Taking all these into consideration, it is not surprising infections remain a leading cause of death worldwide, and will likely reemerge as a significant problem for the US. Historically the United States has been able to significantly control many of the infectious disease that continue to afflict much of the rest of the world; unfortunately the pathogens long held to be other nations' problem, are increasingly becoming a threat to us nevertheless. There are many emerging pathogens of interest that could be contained in this edition, and were we to address all of them you would be holding a large textbook instead of an article. In future editions, the issues of hospital acquired infections will be revisited, as will other emerging threats of importance as timely information becomes available. We are fortunate to be in a somewhat quiet period in terms of deadly outbreaks such as SARS, avian flu, the recent swine flu epidemic, Ebola, and MERS; but we cannot afford to be lulled into complacency. It is our hope this article will increase awareness for, and spur interest in, as well as catalyze activity towards addressing our vulnerabilities to emerging pathogens. In doing so, our patients will be healthier, and our communities can become better prepared for the next epidemics. Nephritis, nephrotic syndrome, and nephrosis 48,146 10. Intentional self-harm (suicide) 42, 773 As Table 2 demonstrates, the United States continues to have significant and largely preventable infection related deaths in spite of improvements to healthcare, newer medications and more advanced interventions over the last two decades. Influenza and pneumonia are vaccine preventable diseases. Albeit host immunity plays a role in the success rates of immunization, nevertheless, if vaccination penetration were significantly improved, there is great likelihood of protection from herd immunity which could contribute to a decline is morbidity as well as mortality. Although one could fill entire editions of medical journals with many of the emerging or persistent and significant pathogens facing health care professionals in the United States, this edition of Disease a Month will focus on emerging respiratory pathogens, influenza viruses, including H7N9, and coronaviruses including MERS CoV, along with a brief discussion on some preventive strategies. Treatment strategies for MERS coronavirus Infectious disease: consideration for the 21 st century World Health Organization (WHO) the top 10 causes of death Fact sheet Zika virus Zika virus: following the path of dengue and Chikungunya? Rapid spread of emerging Zika virus in the Pacific area Zika virus emergence in mosquitoes in southeastern Senegal Zika virus-Suriname, Cape Verde ProMed0mail archive no 20151106 Chikungunya virus. World Health Organization updated Leading causes of death -Data for US deaths per year indicated. Number of deaths for leading causes of death Viral Hemorrhagic Fevers Fact Sheet. Centers for Disease Control and Prevention (CDC) 〈www.CDC.gov〉 Gulf War servicemen and servicewomen: the long road home and the role of health care professionals to enhance the troop's health and healing Health problems after travel to developing countries Measles outbreak shows a global threat Role of Immigrants and Migrants in Emerging Infectious Diseases Changing concepts of airborne infection of acute contagion diseases; a reconsideration of classic epidemiologic theories Avian influenza virus H5N1: a review of its history and information regarding its potential to cause the next pandemic World Health Organization Influenza at the Human animal interface Summary 16 The avian influenza H9N2 at avian human interface: a possible risk for future pandemics US News Infectious Diseases of Concern or the US CDC Emerging and Zoonotic Infectious Diseases FY 2016 President's Budget Request Novel Viruses, emerging pathogens -The Pandemic Threat continues Travel associated illness trends and clusters The role of the traveler IN E emerging infections and magnitude of travel Dengue in travelers Severe respiratory illness caused by a novel coronavirus in a patient transferred to the United Kingdom from the Middle East Avian Influenza: The Next Pandemic Alternative reassortment events leading to transmissible H9N1 influenza viruses in the ferret model High genetic compatibility and increased pathogenicity of reassortants derived from avian H9N2 and pandemic H1N1 20009 influenza viruses Antigenic and genetic characterization of H9N2 swine influenza viruses in China World Health Organization Influenza at the Human animal interface Summary 16 The avian influenza H9N2 at avian human interface: a possible risk for future pandemics Lyme disease -time for a new approach Avian influenza A (H5N1) infection in humans Radiological findings of chest in patients with H7N9 avian influenza from a hospital Human Infection with a novel avian-origin influenza A (H7N9) virus Avian Influenza A (H7N9) Virus Serosurvey of human metapneumoviruses in Croatia Respiratory Syncytial Virus infection in elderly and high risk adults Influenza: lessons from past pandemics, warnings from current incidents Avian influenza: critical considerations for primary care physician CDC statistics on leading causes of death Malaria in the post genome era The changing epidemiology of malaria elimination: new strategies for new challenges Replication cycle of Chikungunya: a re-emerging arbovirus CDC Yellow Book Travel Health Information 〈https Knowledge and use of Preventive Measures for Chikungunya Virus among visitors Virgin Island National Park Pre-travel health advice-seeking behavior among US international travelers departing from Boston Logan International Airport Travel health knowledge, attitudes, and practices among United States travelers Risk factors for infection in international travelers: an analysis of travel-related notifiable communicable diseases Trust for America's Health Reports Severe pneumonia may occur, especially the elderly who have comorbidities, and/or impaired cellular immunity. Aerosolized Ribavirin can be used for RSV in infants. Risk benefit must be balanced when considering the use of Ribavirin in adults. New pathogens are being discovered -some through unknown means, and others through natural adaptation. Globalization, population shifts and the changing ecology, including encroachment of previously unexplored regions has altered the longstanding epidemiology of infectious diseases -causing spread where once continents and oceans contained the pathogen. Influenza viruses are ubiquitous in the animal population It has long been recognized that influenza viruses exchange genetic material, (reassortment) either emerging as a new strain, as we continue to see with H5N1 Given the proximity of people to animals, through occupation and avocation, the human-animal interface becomes a significant risk for human illness from influenza viruses, as has been seen in several outbreaks, including H5N1 since There are a multitude of respiratory pathogens worth describing. However, with the recent emergence of yet another highly pathogenic avian influenza -H7N9 [29,30] and novel coronavirus (MERS CoV) which appears more deadly than SARS