Healthcare worker protection against epidemic viral respiratory disease.

Lower respiratory infections are often caused or precipitated by viruses and are a leading cause of global morbidity and mortality. Mutations in these viral genomes can produce highly infectious strains that transmit across species and have the potential to initiate epidemic, or pandemic, human viral respiratory disease. Transmission between humans primarily occurs via the airborne route and is accelerated by our increasingly interconnected and globalised society. To this date, there have been four major human viral respiratory outbreaks in the 21st century. Healthcare workers (HCWs) are at particular risk during respiratory epidemics or pandemics. This is due to crowded working environments where social distancing, or wearing respiratory personal protective equipment for prolonged periods, might prove difficult, or performing medical procedures that increase exposure to virus-laden aerosols, or bodily fluids. This review aims to summarise the evidence and approaches to occupational risk and protection of HCWs during epidemic or pandemic respiratory viral disease.

Zika, Chikungunya, and Other Emerging Vector-Borne Viral Diseases.

Arthropod-borne viruses (arboviruses) have a long history of emerging to infect humans, but during recent decades, they have been spreading more widely and affecting larger populations. This is due to several factors, including increased air travel and uncontrolled mosquito vector populations. Emergence can involve simple spillover from enzootic (wildlife) cycles, as in the case of West Nile virus accompanying geographic expansion into the Americas; secondary amplification in domesticated animals, as seen with Japanese encephalitis, Venezuelan equine encephalitis, and Rift Valley fever viruses; and urbanization, in which humans become the amplification hosts and peridomestic mosquitoes, mainly Aedes aegypti, mediate human-to-human transmission. Dengue, yellow fever, chikungunya, and Zika viruses have undergone such urban emergence. We focus mainly on the latter two, which are recent arrivals in the Western Hemisphere. We also discuss a few other viruses with the potential to emerge through all of these mechanisms.

Historical Discoveries on Viruses in the Environment and Their Impact on Public Health.

BACKGROUND: Transmission of many viruses occurs by direct transmission during a close contact between two hosts, or by an indirect transmission through the environment. Several and often interconnected factors, both abiotic and biotic, determine the persistence of these viruses released in the environment, which can last from a few seconds to several years. Moreover, viruses in the environment are able to travel short to very long distances, especially in the air or in water. SUMMARY: Although well described now, the role of these environments as intermediaries or as reservoirs in virus transmission has been extensively studied and debated in the last century. The majority of these discoveries, such as the pioneer work on bacteria transmission, the progressive discoveries of viruses, as well as the persistence of the influenza virus in the air varying along with droplet sizes, or the role of water in the transmission of poliovirus, have contributed to the improvement of public health. Recent outbreaks of human coronavirus, influenza virus, and Ebola virus have also demonstrated the contemporaneity of these research studies and the need to study virus persistence in the environment. Key Messages: In this review, we discuss historical discoveries that contributed to describe biotic and abiotic factors determining viral persistence in the environment.

Transmission and prevention of acute viral respiratory tract infections in hospitals.

PURPOSE OF REVIEW: Transmission of acute respiratory tract viral infections in healthcare environments is a major problem worldwide. We review recent literature of viruses imported to hospitals from the local community and from abroad, their modes of transmission and measures required to reduce and contain them. RECENT FINDINGS: Common causes of outbreaks include influenza viruses, respiratory syncytial virus, adenovirus, and coronaviruses. Major lethal outbreaks of viral respiratory infections in hospitals have been caused by coronaviruses imported from abroad by travelers. SUMMARY: Although viruses circulating in the local community are common causes of hospital outbreaks, major outbreaks have been caused by the coronaviruses imported from abroad by travelers. A high degree of clinical awareness and rapid enforcement of infection control measures are required to prevent transmission and spread.

Ultrasound Findings Associated With Antepartum Viral Infection.

This article reviews the sonographic manifestations of fetal infection and the role of ultrasound in the evaluation of the fetus at risk for congenital infection. Several ultrasound findings have been associated with in utero fetal infections. For the patient with a known or suspected fetal infection, sonographic identification of characteristic abnormalities can provide useful information for counseling and perinatal management. Demonstration of such findings in the low-risk patient may serve to identify the fetus with a previously unsuspected infection. The clinician should understand the limitations of ultrasound in the prenatal diagnosis of congenital infection and discuss them with the patient.

Aedes vittatus (Bigot) mosquito: An emerging threat to public health.

Aedes vittatus (Bigot) mosquito is a voracious biter of humans and has a geographical distribution throughout tropical Asia, Africa and the Mediterranean region of Europe. It is predominantly a rock-hole breeder, though it can breed in diverse macro- and micro-habitats. The mosquito plays an important role in the maintenance and transmission of yellow fever (YFV), dengue (DENV), chikungunya (CHIKV) and Zika (ZIKV) viruses. It has been implicated as an important vector of YFV in several African countries as evidenced by repeated virus isolations from the mosquito and its potential to transmit the virus experimentally. Similarly, DENV-2 has been isolated from wild caught Ae. vittatus mosquitoes in Senegal, Africa which has been shown to circulate the virus in sylvatic populations without causing human infection. Experimental studies have shown replication of the virus at a low scale in naturally infected mosquitoes while high rate of infection and dissemination have been reported in parenterally infected mosquitoes. Natural isolation of ZIKV has been reported from Senegal and Cote d'Ivoire from these mosquitoes. They were found highly competent to transmit the virus experimentally and the transmission rate is at par with Ae. leuteocephalus, the primary vector of ZIKV. A few CHIKV isolations have also been reported from the mosquitoes in Senegal and other countries in Africa. Experimental studies have demonstrated high susceptibility, early dissemination and efficient transmission of CHIKV by Ae. vittatus mosquitoes. The mosquitoes with their high susceptibility and competence to transmit important viruses, viz. YFV, DENV, CHIKV and ZIKV pose a major threat to public health due to their abundance and anthropophilic behaviour.

Beyond equipment distribution in Needle and Syringe Programmes: an exploratory analysis of blood-borne virus risk and other measures of client need.

BACKGROUND: Despite high levels of equipment distribution through Needle and Syringe Programmes (NSPs) in Australia, the levels of reuse of equipment among people who inject drugs remain concerning. This paper used an exploratory analysis to examine the needs of NSP client that could be addressed by NSPs to enhance service impact and blood-borne virus risk practices. METHODS: People who inject drugs were recruited from six NSP sites in Sydney, Australia, to undertake a self-completed survey. RESULTS: Using the responses of 236 NSP client participants, three factors were identified in an exploratory factor analysis: recent risky injection (Eigenvalue 3.63, 20.2 % of variance); disadvantage and disability (Eigenvalue 2.26, 12.5 % of variance); and drug use milieu (Eigenvalue 1.50, 8.4 % of variance). To understand the distribution of these factors, the standardised factor scores were dichotomised to explore those participants with 'above average' vulnerability on each factor. A small group of NSP clients reported a cluster of vulnerability measures. Most participants (55.5 %) reported vulnerability on none or only one factor, indicating that 45.5 % could be considered as having double (35.6 %) or triple (8.9 %) vulnerability. CONCLUSIONS: These results challenge NSPs to understand the heterogeneity among their client group and develop programmes that respond to their clients' range of needs beyond those immediately associated with blood-borne virus (BBV) risk. This paper contributes to the growing evidence base regarding the need for BBV prevention efforts to examine strategies beyond equipment distribution.

Role of xenotransplantation in cardiac transplantation.

This review will discuss the history and development of the field of genetic modification, up to the most recent scientific discoveries, and will also consider the current uses of genetic therapy.

Recommendations for live viral and bacterial vaccines in immunodeficient patients and their close contacts.

The present uncertainty of which live viral or bacterial vaccines can be given to immunodeficient patients and the growing neglect of societal adherence to routine immunizations has prompted the Medical Advisory Committee of the Immune Deficiency Foundation to issue recommendations based on published literature and the collective experience of the committee members. These recommendations address the concern for immunodeficient patients acquiring infections from healthy subjects who have not been immunized or who are shedding live vaccine-derived viral or bacterial organisms. Such transmission of infectious agents can occur within the hospital, clinic, or home or at any public gathering. Collectively, we define this type of transmission as close-contact spread of infectious disease that is particularly relevant in patients with impaired immunity who might have an infection when exposed to subjects carrying vaccine-preventable infectious diseases or who have recently received a live vaccine. Immunodeficient patients who have received therapeutic hematopoietic stem transplantation are also at risk during the time when immune reconstitution is incomplete or while they are receiving immunosuppressive agents to prevent or treat graft-versus-host disease. This review recommends the general education of what is known about vaccine-preventable or vaccine-derived diseases being spread to immunodeficient patients at risk for close-contact spread of infection and describes the relative risks for a child with severe immunodeficiency. The review also recommends a balance between the need to protect vulnerable subjects and their social needs to integrate into society, attend school, and benefit from peer education.

Transmission of infection by flexible gastrointestinal endoscopy and bronchoscopy.

Flexible endoscopy is a widely used diagnostic and therapeutic procedure. Contaminated endoscopes are the medical devices frequently associated with outbreaks of health care-associated infections. Accurate reprocessing of flexible endoscopes involves cleaning and high-level disinfection followed by rinsing and drying before storage. Most contemporary flexible endoscopes cannot be heat sterilized and are designed with multiple channels, which are difficult to clean and disinfect. The ability of bacteria to form biofilms on the inner channel surfaces can contribute to failure of the decontamination process. Implementation of microbiological surveillance of endoscope reprocessing is appropriate to detect early colonization and biofilm formation in the endoscope and to prevent contamination and infection in patients after endoscopic procedures. This review presents an overview of the infections and cross-contaminations related to flexible gastrointestinal endoscopy and bronchoscopy and illustrates the impact of biofilm on endoscope reprocessing and postendoscopic infection.

Rugby contact and collisions--clinical challenges of a global game.

Rugby Union (rugby) is a sport that evolved from and resembles other forms of football but is unique in many respects and presents distinctive clinical challenges. This article discusses those aspects of rugby that are different from other sports and those injuries that have specific significance to the game as a result of it being a global collision sport with an increasing focus on serious injury prevention. Injury screening and intervention programs, neck injuries, rugby's contribution to evolving concussion protocols, contact and travel-related illnesses, and rugby's drug intervention protocols are discussed.

Viral infection transmission and indoor air quality: A systematic review.

Respiratory disease transmission in indoor environments presents persistent challenges for health authorities, as exemplified by the recent COVID-19 pandemic. This underscores the urgent necessity to investigate the dynamics of viral infection transmission within indoor environments. This systematic review delves into the methodologies of respiratory infection transmission in indoor settings and explores how the quality of indoor air (IAQ) can be controlled to alleviate this risk while considering the imperative of sustainability. Among the 2722 articles reviewed, 178 were retained based on their focus on respiratory viral infection transmission and IAQ. Fifty eight articles delved into SARS-CoV-2 transmission, 21 papers evaluated IAQ in contexts of other pandemics, 53 papers assessed IAQ during the SARS-CoV-2 pandemic, and 46 papers examined control strategies to mitigate infectious transmission. Furthermore, of the 46 papers investigating control strategies, only nine considered energy consumption. These findings highlight clear gaps in current research, such as analyzing indoor air and surface samples for specific indoor environments, oversight of indoor and outdoor parameters (e.g., temperature, relative humidity (RH), and building orientation), neglect of occupancy schedules, and the absence of considerations for energy consumption while enhancing IAQ. This study distinctly identifies the indoor environmental conditions conducive to the thriving of each respiratory virus, offering IAQ trade-offs to mitigate the risk of dominant viruses at any given time. This study argues that future research should involve digital twins in conjunction with machine learning (ML) techniques. This approach aims to enhance IAQ by analyzing the transmission patterns of various respiratory viruses while considering energy consumption.

Waterborne human pathogenic viruses of public health concern.

In recent years, the impending impact of waterborne pathogens on human health has become a growing concern. Drinking water and recreational exposure to polluted water have shown to be linked to viral infections, since viruses are shed in extremely high numbers in the faeces and vomit of infected individuals and are routinely introduced into the water environment. All of the identified pathogenic viruses that pose a significant public health threat in the water environment are transmitted via the faecal-oral route. This group, are collectively known as enteric viruses, and their possible health effects include gastroenteritis, paralysis, meningitis, hepatitis, respiratory illness and diarrhoea. This review addresses both past and recent investigations into viral contamination of surface waters, with emphasis on six types of potential waterborne human pathogenic viruses. In addition, the viral associated illnesses are outlined with reference to their pathogenesis and routes of transmission.

Infection control and postexposure prophylaxis for the pregnant healthcare worker.

Pregnant health care workers (HCW) may be exposed to pathogens during routine patient care duties. Although they do not seem to be at higher risk for infection compared with nonpregnant HCW, certain infections can be associated with increased maternal morbidity, mortality, and adverse perinatal outcomes. Primary prevention through vaccination is crucial. Medical providers must know which vaccines are safe during pregnancy and which should be postponed until after delivery. Pregnancy should not be a contraindication for certain postexposure prophylaxis regimens after an occupational exposure. Pregnant HCW need to be educated about specific occupational risks and the recommended infection control precautions.