Incidence Of Tularemia Research Articles

Integrated surveillance: Joint modeling of rodent and human tularemia cases in Finland

ObjectiveWe seek to integrate multiple streams of geo-coded information withthe aim to improve public health surveillance accuracy and efficiency.Specifically for vector-borne diseases, knowledge of spatial andtemporal patterns of vector distribution can help early prediction ofhuman incidence. To this end, we develop joint modeling approachesto evaluate the contribution of vector or reservoir information on earlyprediction of human cases. A case study of spatiotemporal modelingof tularemia human incidence and rodent population data from Finnishhealth care districts during the period 1995-2013 is provided. Resultssuggest that spatial and temporal information of rodent abundance isuseful in predicting human cases.IntroductionAn increasing number of geo-coded information streams areavailable with possible use in disease surveillance applications.In this setting, multivariate modeling of health and non-health dataallows assessment of concurrent patterns among data streams andconditioning on one another. Therefore it is appropriate to considerthe analysis of their spatial distributions together. Specifically forvector-borne diseases, knowledge of spatial and temporal patternsof vector distribution could inform incidence in humans. Tularemiais an infectious disease endemic in North America and parts ofEurope. In Finland tularemia is typically mosquito-transmitted withrodents serving as a host; however a country-wide understanding ofthe relationship between rodents and the disease in humans is stilllacking. We propose a methodology to help understand the associationbetween human tularemia incidence and rodent population levels.MethodsData on rodent population levels are collected around the countryby the Finnish Natural Resources Institute. Human Tularaemia casesare recorded as laboratory-confirmed and reported to the NationalInfectious Disease Register (NIDR). Human cases and rodent datawere aggregated to match the 20 Finnish health districts over the period1995-2013 [1]. We develop our methodology in a Bayesian setting.The counts of human cases for each health district in a given yearare assumed to follow a Poisson distribution and the rodent data areassumed to have a categorical likelihood. The linear predictors linkedto the human and rodent likelihood functions are then decomposedadditively into spatial, temporal, and space-time interaction randomeffects. We then link the two likelihoods via the interaction term byassuming that the human spatiotemporal variation is dependent on therodent activity with one-year lag. In the case of the rodent data, wealso included two additional spatial and non-spatial contextual termsto better model ecological effects associated with rodent populationlevels as described before [2]. We then finally develop indicators, onthe scale 0 to 1, to quantify the association between human incidenceand a rodent vector.ResultsResults suggest that spatial and temporal information of rodentabundance is useful in predicting human cases.ConclusionsFuture modeling directions are recommended to includeenvironmental and epidemiological factors. To the best of ourknowledge, this is the first time that rodent data, captured for non-health related purposes, is used to better inform the human risk oftularemia in Finland.

Эпизоотическая и эпидемическая ситуации по туляремии в Российской Федерации в 2015 г. и прогноз на 2016 г.

Analyzed are the data on epizootiological and epidemiological surveillance of tularemia foci, situated in the territory of 85 constituent entities of the Russian Federation. Positive findings, obtained in the process of examination of small mammals, Ixodidae ticks, mosquitoes, and environmental objects, using immunological and molecular-genetic methods; isolated tularemia agent cultures; as well as tularemia incidence rates among the population have made provisions for the assessment of circulation and infection activity in the Regions. In period of 2015, 71 cases of human infection with tularemia have been registered. Given is a brief characteristics of activity of the natural tularemia foci and epidemic situation in the territory of the Russian Federation in 2015. Specified are the regions where preventive vaccination is on a low level. Given is the differentiation of RF territories according to the risk of exposure to tularemia infection for 2016.

Specification of Morbidity Rates among the Population of the Tula Region as Regards Natural-Focal Infectious Diseases

Objective of the study was to analyze morbidity rates, structure, and spatial distribution of natural-focal infections in the Tula Region. Based on statistical reports of the Center of Hygiene and Epidemiology in the Tula Region over a period of 1993-2013, it is demonstrated that zoonotic infections that occur in the Tula Region, are hemorrhagic fever with renal syndrome (HFRS), leptospirosis, Ixodidae tick-borne borreliosis, and tularemia in the ratio of 60.2:33.6:5.5:0.7, respectively. An average case rate for HFRS and leptospirosis is 1.3 and 4.9 times higher than the corresponding rates throughout Russia, respectively, while Ixodidae tick-borne borreliosis, and tularemia incidence is, by contrast, 9.2 and 2.1 times lower, than the national average. Dynamics of HFRS morbidity rates and Ixodidae tick-borne borreliosis is marked by a moderate upward trend, while leptospirosis and tularemia incidence levels have an apparent downward trend. The highest HFRS, leptospirosis, and Ixodidae tick-borne borreliosis morbidity is in the northern, north-western and western parts of the Region, situated in broadleaved woodland; and the highest numbers of tularemia cases are registered in two eastern zones.

Epidemiology and ecology of tularemia in Sweden, 1984-2012.

The zoonotic disease tularemia is endemic in large areas of the Northern Hemisphere, but research is lacking on patterns of spatial distribution and connections with ecologic factors. To describe the spatial epidemiology of and identify ecologic risk factors for tularemia incidence in Sweden, we analyzed surveillance data collected over 29 years (1984-2012). A total of 4,830 cases were notified, of which 3,524 met all study inclusion criteria. From the first to the second half of the study period, mean incidence increased 10-fold, from 0.26/100,000 persons during 1984-1998 to 2.47/100,000 persons during 1999-2012 (p<0.001). The incidence of tularemia was higher than expected in the boreal and alpine ecologic regions (p<0.001), and incidence was positively correlated with the presence of lakes and rivers (p<0.001). These results provide a comprehensive epidemiologic description of tularemia in Sweden and illustrate that incidence is higher in locations near lakes and rivers.

Ecoepidemiology of Tularemia in the Southcentral United States

We combined county-based data for tularemia incidence from 1990 to 2003 for a nine-state region (Arkansas, Illinois, Indiana, Kansas, Kentucky, Missouri, Nebraska, Oklahoma, and Tennessee) in the southcentral United States with Geographic Information System (GIS)-based environmental data to determine associations between coverage by different habitats (especially dry forest representing suitable tick habitat) and tularemia incidence. High-risk counties (> 1 case per 100,000 person-years) clustered in Arkansas-Missouri and far eastern Oklahoma and Kansas. County tularemia incidence was positively associated with coverage by dry forested habitat suitable for vector ticks for Oklahoma-Kansas-Nebraska and Arkansas-Missouri but not for Illinois-Indiana-Kentucky-Tennessee. A multivariate logistic regression model predicting presence of areas with risk of tularemia based on GIS-derived environmental data was developed for the Arkansas-Missouri tularemia focus. The study shows the potential for research on tularemia ecoepidemiology and highlights the need for further modeling efforts based on acarologic data and more fine-scale point or zip code/census tract epidemiologic data.

A CUSUM framework for detection of space–time disease clusters using scan statistics

Several methods for timely detection of emerging clusters of diseases have recently been proposed. We focus our attention on one of the most popular types of method; a scan statistic. Different ways of constructing space-time scan statistics based on surveillance theory are presented. We bridge the ideas from space-time disease surveillance, public health surveillance and industrial quality control and show that previously suggested space-time scan statistics methods can be fitted into a general CUSUM framework. Crucial differences between the methods studied are due to different assumptions about the spatial process. An example is the specification of the spatial regions of interest for a possible cluster, another is the increased rate to be detected within a cluster. We evaluate the detection ability of the methods considering the possibility of a cluster emerging at any time during the surveillance period. The methods are applied to the detection of an increased incidence of Tularemia in Sweden.

Tularemia

Tularemia as a potential biological weapon is of great concern because F. tularensis is a hardy organism that can be spread with a small inoculum. In addition, tularemia can be contracted through nature, predominately in rural areas. This disease can be spread by a wide variety of animals and can range from skin lesions to multi-organ involvement. The severity varies with amount of inocula, the virulence of the bacterium, and the port of entry. Exposure to aerosolized forms of F. tularensis, the major concern with bioterroism, can rapidly lead to respiratory failure and death. Untreated, other forms of tularemia can spread through the blood stream to other organs, leading to sepsis and death. Early recognition and treatment is tantamount to treatment and prevention of morbidity and mortality. Occupational health nurses are on the front line and must be assertive in identifying risk factors associated with exposure. Furthermore, education of the general population about exposure through nature can potentially decrease the incidence of tularemia. Occupational health nurses, as one of the largest health specialties in the workplace, may be the first contact for the exposed individual. Tularemia is treatable with knowledge of prevention, astute assessment, prompt identification, and treatment. Combined, they are powerful nursing tools in achieving optimal outcomes.

TULAREMIA OF THE MIDDLE EAR

We report the case of a 10-year-old boy with prolonged fever who was found to have tularemia of the middle ear. Otolaryngologic cases including oropharyngeal and glandular or ulceroglandular forms of the head and neck region are estimated to account for 12% of all tularemia cases, but to date we have not seen a report of tularemia in the middle ear. The possibility of tularemia may not occur to a physician because of the wide variation of clinical manifestations.

Tularemia in children

Eight of 50 hospitalized cases of tularemia occurred among children. Of these 8 cases, 6 were of the ulceroglandular, 1 of the oculoglandular, and 1 of the oropharyngeal type. All presented with fever and regional adenopathy relative to the site of infection. The incidence of tularemia is greatest during rabbit hunting season since the rabbit is the most frequent source of infection. Streptomycin is the drug of choice. Therapy initiated after 2 weeks of illness may be less effective in shortening the course of disease than earlier antibiotic treatment. Recovery is usually complete without residua.

Laboratory-acquired tularemia in vaccinated individuals: a report of 62 cases.

Excerpt A high incidence of tularemia among nonvaccinated laboratory workers has been recognized.1-12Almost every individual who consistently works withPasteurella tularensiseventually incurs infec...

Notes on the Family Leptinidae Including a New Record of Leptinillus Validus (Horn) in North America (Coleoptera)1

Following a recent investigation conducted to determine the incidence of tularemia in northern Minnesota beavers, a small number of adult beetles taken from the fur of these animals were sent to the senior author by Mr. Milton Stenlund, of the Minnesota State Department of Conservation, who stated that the beetles frequently had been observed on beavers during the course of the investigation and requested information concerning the economic importance of the beetle.

Incidence of tularemia and Rocky Mountain spotted fever among common ticks of Arkansas.

SummaryIn the course of a year's field study in Arkansas, 576 pools totalling 28,661 lone star ticks (Amblyomma americanum) were tested for tularemia by animal inoculation, and 11 pools (1.9 per cent) were found positive—an average of one infected tick in 2,605, assuming only one infected individual to each positive pool. The distribution of naturally infected ticks was shown to be spotty, and the finding of a batch of infected, unfed larvae of A. americanum indicates the probable occurrence of transovarian passage of tularemia in this species.The lone star tick was the only arthropod found naturally infected with tularemia, although the number of other ticks tested was insufficient to justify general conclusions. Tularemia-infected lone star ticks were collected in May, July, and September, coinciding with the reported seasonal incidence of human infections; and the data presented, taken in connection with previous epidemiologic investigations, point to ticks as the chief vectors of tularemia in Arkansas.Pools of lone star, American dog, black-legged and rabbit ticks were tested by animal inoculation for Rocky Mountain spotted fever organisms (R. rickettsi), but only one successful isolation was made, from the tissues of a guinea pig inoculated from a pool of female American dog ticks. Reactions of several guinea pigs inoculated with material from pools of lone star ticks indicated rickettsial infections, but the organism was not recovered from the test animals.

Some Epidemiological Observations on Tularemia in California 1927–1951

Summary A study of 266 authenticated cases of tularemia in California occurring from 1927–1951 showed that 81 per cent were contracted from wild rabbits. The jack rabbit appears to be more frequently involved than the cottontail, in contrast with the findings of Eastern writers. Other wild animals found infected were several species of ground squirrels and field mice, and in a few cases the brown rat. Infected arthropods found in California are chiefly ticks, although the role of rabbit fleas deserves further study, and possibly that of deerflies and horseflies. The incidence of tularemia in the decade 1933–1942 was 16 cases a year but it has declined during the last ten years to an average of 6 cases which may in part be due to decreased reporting by clinicians who now have an effective antibiotic at hand. The seasonal occurrence with its peak in summer is associated with rabbit hunting and arthropod vector activity, but there is no correlation with the legal hunting season of cottontail rabbits. Age and sex distributions reflect the opportunity of exposure to wild rabbits. Occupation, even that of butchers, who do not handle wild rabbits plays little or no part in the epidemiology. Cases occur mainly among sportsmen and housewives who dress and cook the game. The incidence of tularemia in California does not warrant its consideration as a major public health problem. An educational effort, particularly in the counties of greatest incidence, might help to prevent infection in hunters and their wives by teaching them how to avoid exposure when handling wild rabbits.

Tularemia Geographical Distribution of "Deerfly Fever" and the BitingFly, Chrysops discalis Williston

Deerfly fever was described by Pearse (1) in 1911 as a disease entity of man in Utah where it had been recognized by physicians for several years. It is one of the many epidemiological manifestations of tularemia, an infectious bacterial disease of man and other animals, named and described by Francis (2) in 1920. While most cases of fever would be classed clinically as an ulceroglandular type of tularemia, epidemiologically, the cases are distinct in that (a) the initial lesion at the site of infection is usually on an exposed part of the body, i. e., hands, arms, face, or neck; (b) most of the cases occur in June, July, and August; (c) the disease has a rather restricted geographical distribution in contrast to tularemia in general, as shown in this study; and (d) the patient often observes being bitten by a deerfly and later recalls the incident when an initial lesion or ulcer develops at the site. The successful experimental studies by Francis and Mayne (3) on the transmission of tularemia by deerflies were undertaken because, as they state, popular belief had connected the occurrence of human cases of tularemia with the bites of Chrysops discalis. This species was abundant in areas where human cases were common and was known to bite man. Although it proved to be an efficient experimental vector, Francis and Mayne did not find natural infection nor did they observe the deerflies feeding on wild rabbits, a presumed source of infection in nature. A few cases of tularemia from deerfly bites are reported nearly every year in the West. At least one epidemic occurred among Civilian Conservation Corps workers near Locomotive Springs, north of Great Salt Lake, Utah, in 1935, as reported by Hillman and Morgan (4). Typical cases of fever appear to be confined to certain Western States and Canadian provinces in contrast to other epidemiological forms of tularemia which are widely distributed throughout the United States, and to a lesser extent in Canada. It is especially noticeable that few or no cases of deerfiy fever are reported in States of high tularemia incidence east of the Mississippi River. This case distribution suggests a study of and comparison with the

Incidence of Tularemia in New York State

THE apparent limitation of tularemia to certain sections of the United States is surprising in view of the great variety of animals and birds which have been shown to be susceptible to this disease. So far as can be determined, only 12 cases, enumerated in Table I, are known to have occurred in New York State, and 10 of them were attributed to the handling of rabbits either known or thought to have -been imported from other states. In but 1 instance (case No. 3) was a wild animal in this state, a deer, indicated as the source of the incitant. Since no reference has been found in the literature to this species having been infected with B. tularense, a brief history may be of interest. The patient, a man, frequently butchered and skinned animals, especially during the hunting season. He handled the carcasses of raccoons and hogs 2 days after the first symptoms developed, but the information obtained indicated that there had been no opportunity for infection from these or other animals for a considerable time prior to his illness. On November 8,1930, during a hunting trip, he injured his left index finger while handling his rifle. Later that day, he dressed a deer which he had shot, and, on November 10, skinned the animal. On November 13 and 14, he complained of feeling ill and thought he had grippe. Congestion and pus formation were noted at the site of the wound on his finger. Dr. A. L. Hayes of Willsboro, N. Y., the local health officer, was consulted about 3 weeks after the injury occurred.At that time, in addition to the lesion on the finger, which still persisted, a painful gland, approximately the size of a pigeon's egg, was noted in the left axilla. A clinical diagnosis of tularemia was made, and a specimen of blood, sent to this laboratory on December 2, agglutinated B. tularense in a 1:320 dilution.

Tularemia*

Tularemia*

Seasonal Incidence of Tularemia and Sources of Infection

Seasonal Incidence of Tularemia and Sources of Infection