Estimating the effectiveness of vaccine programs in dog populations.

Dogs harbor numerous zoonotic pathogens, many of which are controlled through vaccination programs. The delivery of these programs can be difficult where resources are limited. We developed a dynamic model to estimate vaccination coverage and cost-per-dog vaccinated. The model considers the main factors that affect vaccination programs: dog demographics, effectiveness of strategies, efficacy of interventions and cost. The model was evaluated on data from 18 vaccination programs representing eight countries. Sensitivity analysis was performed for dog confinement and vaccination strategies. The average difference between modelled vaccination coverage and field data was 3.8% (2.3%-5.3%). Central point vaccination was the most cost-effective vaccination strategy when >88% of the dog population was confined. More active methods of vaccination, such as door-to-door or capture-vaccinate-release, achieved higher vaccination coverage in free-roaming dog populations but were more costly. This open-access tool can aid in planning more efficient vaccination campaigns in countries with limited resources.

Dog Ecology and Barriers to Canine Rabies Control in the Republic of Haiti, 2014-2015.

An estimated 59 000 persons die annually of infection with the rabies virus worldwide, and dog bites are responsible for 95% of these deaths. Haiti has the highest rate of animal and human rabies in the Western Hemisphere. This study describes the status of animal welfare, animal vaccination, human bite treatment, and canine morbidity and mortality in Haiti in order to identify barriers to rabies prevention and control. An epidemiologic survey was used for data collection among dog owners during government-sponsored vaccination clinics at fourteen randomly selected sites from July 2014 to April 2015. A total of 2005 surveys were collected and data were analysed using parametric methods. Over 50% of owned dogs were allowed to roam freely, a factor associated with rabies transmission. More than 80% of dog owners reported experiencing barriers to accessing rabies vaccination for their dogs. Nearly one-third of the dog population evaluated in this study died in the year preceding the survey (32%) and 18% of these deaths were clinically consistent with rabies. Dog bites were commonly reported, with more than 3% of the study population bitten within the year preceding the survey. The incidence of canine rabies in Haiti is high and is exacerbated by low access to veterinary care, free-roaming dog populations and substandard animal welfare practices. Programmes to better understand the dog ecology and development of methods to improve access to vaccines are needed. Rabies deaths are at historical lows in the Western Hemisphere, but Haiti and the remaining canine rabies endemic countries still present a significant challenge to the goal of rabies elimination in the region.

Perceptions and Practices of Mass Bat Exposure Events in the Setting of Rabies Among U.S. Public Health Agencies.

Current guidelines in the setting of exposures to potentially rabid bats established by the Advisory Committee on Immunization Practices (ACIP) address post-exposure prophylaxis (PEP) administration in situations where a person may not be aware that a bite or direct contact has occurred and the bat is not available for diagnostic testing. These include instances when a bat is discovered in a room where a person awakens from sleep, is a child without an adult witness, has a mental disability or is intoxicated. The current ACIP guidelines, however, do not address PEP in the setting of multiple persons exposed to a bat or a bat colony, otherwise known as mass bat exposure (MBE) events. Due to a dearth of recommendations for response to these events, the reported reactions by public health agencies have varied widely. To address this perceived limitation, a survey of 45 state public health agencies was conducted to characterize prior experiences with MBE and practices to mitigate the public health risks. In general, most states (69% of the respondents) felt current ACIP guidelines were unclear in MBE scenarios. Thirty-three of the 45 states reported prior experience with MBE, receiving an average of 16.9 MBE calls per year and an investment of 106.7 person-hours annually on MBE investigations. PEP criteria, investigation methods and the experts recruited in MBE investigations varied between states. These dissimilarities could reflect differences in experience, scenario and resources. The lack of consistency in state responses to potential mass exposures to a highly fatal disease along with the large contingent of states dissatisfied with current ACIP guidance warrants the development of national guidelines in MBE settings.

Clinical management and humoral immune responses to rabies post-exposure prophylaxis among three patients who received solid organs from a donor with rabies.

BACKGROUND: The rabies virus causes a fatal encephalitis and can be transmitted through organ transplantation. In 2013, a man developed rabies 18 months after receiving a kidney from a donor with rabies, who was not known to have been infected when the organs were procured. Three additional persons who received organs from the same donor (liver, kidney, heart), all of whom were not vaccinated for rabies before transplantation, received rabies post-exposure prophylaxis (PEP) with rabies immune globulin and 5 doses of rabies vaccine as soon as the diagnosis of rabies was made in the donor (18 months after their transplant surgeries). We describe their clinical management. METHODS: As the 3 recipients were all on immunosuppressive medications, post-vaccination serologic testing was performed using the rapid fluorescent focus inhibition test to measure rabies virus neutralizing antibodies (RVNAs). An acceptable antibody response to administration of rabies vaccine was defined as detection of RVNAs at a concentration ≥0.1 IU/mL from a serum specimen collected ≥7 days after the fifth vaccine dose. RESULTS: All 3 recipients demonstrated an acceptable antibody response despite their immunosuppressed states. More than 36 months have passed since their transplant surgeries, and all 3 recipients have no evidence of rabies. CONCLUSIONS: The survival of 3 previously unvaccinated recipients of solid organs from a donor with rabies is unexpected. Although the precise factors that led to their survival remain unclear, our data suggest that PEP can possibly enhance transplant safety in settings in which donors are retrospectively diagnosed with rabies.

Community survey of rabies knowledge and exposure to bats in homes - Sumter County, South Carolina, USA.

Subsequent to a human rabies death in Sumter County, South Carolina, we assessed the frequency of exposures to bats in homes and citizens' rabies knowledge. A self-administered survey was mailed to 6033 randomly selected Sumter County addresses. The survey inquired about household exposures to bats and respondents' rabies knowledge. Surveys were returned by mail for descriptive analysis. Of 597 respondents, 3.5% (21/597) reported having bats living in (2.8% or 17/597) or entering their homes (2.5% or 15/597) during 2010-2012. Respondents generally understood that mammals transmit rabies virus through bites, but were less aware of the severity of rabies illness and modern post-exposure vaccine administration. Respondents were unsure about how to exclude bats from homes and ranked highly both healthcare and non-healthcare entities as preferred resources for obtaining assistance with bat-related concerns. We found potential for human exposures to bats in Sumter County households and gaps in citizen knowledge of rabies and bat exclusion. Public health officials should engage non-healthcare partners in assistance disseminating rabies educational materials and for providing appropriate referral for persons potentially exposed to bats.

A large-scale, rapid public health response to rabies in an organ recipient and the previously undiagnosed organ donor.

This article describes and contrasts the public health response to two human rabies cases: one organ recipient diagnosed within days of symptom onset and the transplant donor who was diagnosed 18 months post-symptom onset. In response to an organ-transplant-related rabies case diagnosed in 2013, organ donor and recipient investigations were conducted by multiple public health agencies. Persons with potential exposure to infectious patient materials were assessed for rabies virus exposure. An exposure investigation was conducted to determine the source of the organ donor's infection. Over 100 persons from more than 20 agencies spent over 2700 h conducting contact investigations in healthcare, military and community settings. The 564 persons assessed include 417 healthcare workers [5.8% recommended for post-exposure prophylaxis (PEP)], 96 community contacts (15.6% recommended for PEP), 30 autopsy personnel (50% recommended for PEP), and 21 other persons (4.8% recommended for PEP). Donor contacts represented 188 assessed with 20.2% recommended for PEP, compared with 5.6% of 306 recipient contacts recommended for PEP. Human rabies cases result in substantial use of public health and medical resources, especially when diagnosis is delayed. Although rare, clinicians should consider rabies in cases of encephalitis of unexplained aetiology, particularly for cases that may result in organ donation.

A conceptual model for the impact of climate change on fox rabies in Alaska, 1980-2010.

The direct and interactive effects of climate change on host species and infectious disease dynamics are likely to initially manifest\ at latitudinal extremes. As such, Alaska represents a region in the United States for introspection on climate change and disease. Rabies is enzootic among arctic foxes (Vulpes lagopus) throughout the northern polar region. In Alaska, arctic and red foxes (Vulpes vulpes) are reservoirs for rabies, with most domestic animal and wildlife cases reported from northern and western coastal Alaska. Based on passive surveillance, a pronounced seasonal trend in rabid foxes occurs in Alaska, with a peak in winter and spring. This study describes climatic factors that may be associated with reported cyclic rabies occurrence. Based upon probabilistic modelling, a stronger seasonal effect in reported fox rabies cases appears at higher latitudes in Alaska, and rabies in arctic foxes appear disproportionately affected by climatic factors in comparison with red foxes. As temperatures continue a warming trend, a decrease in reported rabid arctic foxes may be expected. The overall epidemiology of rabies in Alaska is likely to shift to increased viral transmission among red foxes as the primary reservoir in the region. Information on fox and lemming demographics, in addition to enhanced rabies surveillance among foxes at finer geographic scales, will be critical to develop more comprehensive models for rabies virus transmission in the region.

Prevention and control of rabies in an age of global travel: a review of travel- and trade-associated rabies events--United States, 1986-2012.

Rabies prevention and control efforts have been successful in reducing or eliminating virus circulation regionally through vaccination of specific reservoir populations. A notable example of this success is the elimination of canine rabies virus variant from the United States and many other countries. However, increased international travel and trade can pose risks for rapid, long-distance movements of ill or infected persons or animals. Such travel and trade can result in human exposures to rabies virus during travel or transit and could contribute to the re-introduction of canine rabies variant or transmission of other viral variants among animal host populations. We present a review of travel- and trade-associated rabies events that highlight international public health obligations and collaborative opportunities for rabies prevention and control in an age of global travel. Rabies is a fatal disease that warrants proactive coordination among international public health and travel industry partners (such as travel agents, tour companies and airlines) to protect human lives and to prevent the movement of viral variants among host populations.

Rabies prevention and management of cats in the context of trap-neuter-vaccinate-release programmes.

Domestic cats are an important part of many Americans' lives, but effective control of the 60-100 million feral cats living throughout the country remains problematic. Although trap-neuter-vaccinate-return (TNVR) programmes are growing in popularity as alternatives to euthanizing feral cats, their ability to adequately address disease threats and population growth within managed cat colonies is dubious. Rabies transmission via feral cats is a particular concern as demonstrated by the significant proportion of rabies post-exposure prophylaxis associated with exposures involving cats. Moreover, TNVR has not been shown to reliably reduce feral cat colony populations because of low implementation rates, inconsistent maintenance and immigration of unsterilized cats into colonies. For these reasons, TNVR programmes are not effective methods for reducing public health concerns or for controlling feral cat populations. Instead, responsible pet ownership, universal rabies vaccination of pets and removal of strays remain integral components to control rabies and other diseases.

Early detection of acute myocardial infarction in patients presenting with chest pain and nondiagnostic ECGs: serial CK-MB sampling in the emergency department.

STUDY OBJECTIVES: Patients presenting to the emergency department with chest discomfort are a difficult problem for emergency physicians. Nearly 50% of patients with acute myocardial infarction (AMI) will initially have nondiagnostic ECGs on ED presentation. The purpose of this study was to determine if patients with AMI having nondiagnostic ECGs could be identified using new immunochemical assays for serial CK-MB sampling in the ED. DESIGN: Chest pain patients, more than 30 years old, with pain not caused by trauma or explained by radiographic findings, were eligible for the study. Serial serum samples were drawn on ED presentation (zero hours) and three hours after presentation, then analyzed for CK-MB using four immunochemical methods and electrophoresis. Standard World Health Organization criteria were used to establish the diagnosis of AMI, including new Q-wave formation or elevation of standard in-hospital serum cardiac enzyme markers. SETTING: A tertiary cardiac care community hospital. MEASUREMENTS AND MAIN RESULTS: The serum from 183 patients hospitalized for possible ischemic chest pain was collected and analyzed. Thirty-one of 183 patients (17%) were found to have AMI by standard in-hospital criteria. Sixteen of the 31 patients (52%) with AMI had nondiagnostic ECGs on presentation. Immunochemical determination of serial CK-MB levels provided a sensitive and specific method for detecting AMI in patients within three hours after ED presentation compared with standard electrophoresis. The four immunochemical methods demonstrated a range in sensitivity from 50% to 62.1% on ED presentation versus 92% to 96.7% three hours later. The immunochemical tests demonstrated specificities ranging from 83.0% to 96.4% at three hours, with three of the four tests having specificities of 92% or greater. Electrophoresis had a sensitivity of 34.5% on ED presentation, increasing to 76.9% at three hours, with a specificity of 98.6%. CONCLUSIONS: Immunochemical CK-MB methods allowed rapid, sensitive detection of AMI in the ED. Early detection of AMI offers many potential advantages to the emergency physician. Early detection of AMI, while the patient is in the ED, could direct disposition of this potentially unstable patient to an intensive care setting. Such information may prevent the ED discharge of patients with AMI having nondiagnostic ECGs. The diagnosis of AMI within a six-hour period after symptom onset may allow thrombolytic therapy to be given to patients with AMI not having diagnostic ECGs. This study served as a pilot trial for a multicenter study of the Emergency Medicine Cardiac Research Group, which is currently ongoing.