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Biomedical subjects

E M Bosler

Publications and source records attributed to E M Bosler.

35 records · Page 2Linked to original sources
PubMed1988

Vector tick populations and Lyme disease. A summary of control strategies.

Although many aspects of Lyme disease have been intensely studied for over a decade, little research has been directed toward control of the principal tick vector, Ixodes dammini. Ecological and epidemiological investigations have provided not only an ample understanding of tick biology and behavior, they have also identified the types of areas at risk for disease transmission. The advantages and limitations of previous attempts to control I. dammini by host reduction, habitat modification, and acaricide applications have been discussed in relation to overall control strategies for high-risk areas, and an integrated approach to control proposed.

Animals↗
PubMed1988

Host responses to Borrelia burgdorferi in dogs and horses.

By using paired sera the IgM and IgG host responses were analyzed in dogs with ELISA and Western blot techniques. Antibodies in clinical seropositive dogs bound to 4-25 IgM and up to 40 or more IgG antigenic determinants. Early IgM response to the 41-kDa flagellin persisted for at least 9 months and involved as many as seven other peptides. IgG response expanded later in the disease and involved more immunogens than are currently recognized in late human disease. A percentage of asymptomatic dogs that later developed clinical symptoms were seropositive. Immunoblot studies suggested that B. burgdorferi is persistent in both asymptomatic and weakly reactive animals and if untreated could lead to disease expression. Clinical seropositive, asymptomatic seronegative, and experimentally infected horses were similarly studied. In experimentally inoculated animals IgG antibodies were initially bound to flagellin and later to the 34- and 31-kDa polypeptides, even though ELISA values were considered only slightly reactive.

Animals↗
PubMed1988

Epidemiologic studies of Lyme disease in horses and their public health significance.

A serologic survey of horses in the New Jersey-Pennsylvania area demonstrated that about 10% (6.2-14.2%) have significant levels of serum antibody to Borrelia burgdorferi. However, in a highly endemic area of central New Jersey, up to 60% of the mares and yearlings samples on one farm were seropositive. In 1983, sera from this same farm exhibited only 12% positives in mares and 35% positives in yearlings. Longitudinal studies of paired sera obtained from individual yearlings over a 6-month period in 1985 showed that 34% of them declined during the period. A new clinical syndrome associated with this farm has been observed in 1985-87. In 1985 only an edema of the legs and a dermatitis were noted, in 19.2% of the foals. There was a clustering of cases on one site, where one peer group of foals was sequestered after weaning, which suggested a point source of infection other than arthropods. In 1986, 14.6% of the foals were affected, four of them with arthritis, two of which resisted antibiotic treatment for over several months' time. Experimental infection of a pony with triturated B. burgdorferi infected tick material indicated low specific antibody levels starting about the ninth day that continued for a 3-week period. When this animal was challenged 6 months later with primary B. burgdorferi cultures, a rapid and significant booster effect was evidenced within 4 days.

Animals↗
PubMed1987

Prevalence of canine Lyme disease from an endemic area as determined by serosurvey.

From August 1984 through February 1985, 423 dogs from 43 municipalities in 7 New Jersey counties were evaluated for the presence of antibodies to the Lyme disease spirochete (Borrelia burgdorferi). Of these dogs, 34.7% with no apparent clinical symptoms were serologically reactive (IFA greater than or equal to 1:64); titers in this study ranged from non-reactive to 1:2048. Ninety percent of the dogs surveyed had a current vaccination status to Leptospira interrogans serovars canicola and icterohaemorhagiae. Dogs vaccinated to leptospirosis elicited homologous antibody titers of less than or equal to 1:16 and, therefore, did not interfere with interpretation of antibody levels to B. burgdorferi. Effects of age, degree of outdoor activity, travel history, and location of residence were evaluated. The use of serosurveys of dogs as a tool for Lyme disease surveillance is discussed.

Age Factors↗
PubMed1987

Adult Ixodes dammini on rabbits: a hypothesis for the development and transmission of Borrelia burgdorferi.

A histological study of unfed Ixodes dammini adults has shown that the Lyme disease spirochete can be found in the midgut diverticula of these ticks and is presumably carried over from the nymphal stage. Sequential histology of the early stages of ticks feeding on a rabbit showed that spirochetes began to divide and were located in close proximity or attached to the epithelial cells of the diverticulae. Evidence for division was obtained by the higher number of spirochetes per tick after a three-day feeding period than in the unfed females. Although the mechanism is unclear, some spirochetes become systemic by the fifth day of feeding and can be detected in low numbers in other tick organs. Spirochetes were also noted in the feeding cavities created by I. dammini in the dermis after five days of attachment. Spirochetes were not detected in salivary glands or in the feces of I. dammini during the feeding period.

Animals↗
PubMed1986

The prevalence and significance of Borrelia burgdorferi in the urine of feral reservoir hosts.

Live Borrelia burgdorferi were isolated from the blood and/or urine of white-footed mice (Peromyscus leucopus) collected on Shelter Island, New York, in 1984 and 1985. Prevalence of spirochetes in urine was consistently higher than in blood or both fluids simultaneously. Spirochetes remained viable for 18-24 hours in urine and were maintained in culture for one week. Mice removed from the field were spirocheturic for at least 13 months. One spirocheturic mouse developed spirochetemia one month after field removal indicating the pathogen can return to the peripheral circulation. Twenty-one kidneys from 22 mice had spirochetes in the interstitial areas and bridging the tubules. A positive correlation between Babesia microti infection and spirocheturia was seen. Although the mechanism of entry into the urine is unknown, B. microti infection may increase glomerular permeability. Babesia induced hematuria may provide possible nutrients to maintain spirochetes. Urine may provide a method for contact non-tick transmission of B. burgdorferi in natural rodent populations particularly during periods of nesting and/or breeding.

Animals↗
PubMed1986

Evolution of a focus of Lyme disease.

Epidemiological investigations were initiated in 1984 when significant Lyme disease activity was observed within a 5-km radius of an area previously used as a non-endemic control site for Lyme disease research in New Jersey. Through 1983, collections of Ixodes dammini from vegetation and feral rodents were infrequent and no human cases were identified within a 16-km radius of the control site. In 1984, 4 human cases and 3 serologically reactive canines (greater than or equal to 1:512) were recognized within the area and adult I. dammini populations were over 3-fold greater than those at our primary study location where Lyme disease has been endemic since 1981. Using darkfield microscopy, 53.4% of adult I. dammini were infected with Borrelia burgdorferi as compared to 50.0% of adults collected during the same period at the known endemic study site. These data indicate that a focus of Lyme disease has recently become established at the previously non-endemic control site and that the establishment of new foci may occur more rapidly than once thought.

Animals↗
PubMed1986

Comparison of rates of infection by the Lyme disease spirochete in selected populations of Ixodes dammini and Amblyomma americanum (Acari: Ixodidae).

At a major endemic focus in New Jersey, 50% of 290 adult Ixodes dammini collected in the fall of 1984 were infected with the Lyme disease spirochete (Borrelia burgdorferi), which was statistically higher than the rate found in the 202 adult ticks (39.6%) examined during the spring. Neither sex nor site of collection within the focus significantly affected the infection rate. The observed infection rates were similar to those reported in endemic areas of New York and Connecticut. Borrelia burgdorferi also infected all active stages of Amblyomma americanum ticks. Rates of infection were 5.4% in adults (n = 467) and 3.4% in nymphs (n = 289); 15.6% of clusters of unengorged larvae harbored B. burgdorferi, suggesting transovarial passage of the spirochete. Comparison of the rates of infection in I. dammini and A. americanum and their potential impact on Lyme disease transmission is discussed.

Analysis of Variance↗
PubMed1984

Amblyomma americanum: a potential vector of Lyme disease in New Jersey.

Amblyomma americanum is a likely secondary vector of Lyme disease in New Jersey. Ticks of this species were removed from the site of the characteristic skin lesion known as erythema chronicum migrans on two patients with the disease, and the Lyme disease spirochete was isolated from nymphs and adults of this species. That A. americanum is a potential vector is supported by its similarities to Ixodes dammini, the known tick vector, in seasonal distribution and host utilization. The extensive range of A. americanum may have great implications for potential Lyme disease transmission outside known endemic areas.

Adult↗
PubMed1984

Incidence and cumulative frequency of endemic Lyme disease in a community.

We conducted an epidemiological study of the cumulative frequency and incidence of Lyme disease in a summer community on Fire Island, New York, an area endemic for the disease. Fifteen (7.5%) of 200 persons studied in the community in 1982 reported a history of Lyme disease. An indirect immunofluorescent antibody assay showed that seventeen (9.7%) of 176 persons had serological evidence of exposure to the Lyme spirochete, including six of the 15 persons with a history of Lyme disease. Seven (0.7%-1.2%) of 600-1,000 persons in the community developed clinical symptoms and serological evidence of Lyme disease during the summer season, including two (1%) of the 200 persons in the study group. Four (3.1%) of 129 persons who had sera collected before and after the summer season demonstrated fourfold or greater rises in IgG antibody titers to the Lyme spirochete, including 2 (1.6%) persons without symptoms of Lyme disease. We conclude that the incidence of Lyme disease can be appreciably higher in endemic areas than previously recognized and that subclinical or inapparent seroconversion may occur after infection.

Adolescent↗
PubMed1984

Interactions of phagocytes with the Lyme disease spirochete: role of the Fc receptor.

The phagocytic capacity of murine and human mononuclear and polymorphonuclear phagocytes (including peripheral blood monocytes and neutrophils), rabbit and murine peritoneal exudate cells, and the murine macrophage cell line P388D1 against the Lyme disease spirochete was studied. All of these cells were capable of phagocytosing the spirochete; phagocytosis was measured by the uptake of radiolabeled spirochetes, the appearance of immunofluorescent bodies in phagocytic cells, and electron microscopy. Both opsonized and nonopsonized organisms were phagocytosed. The uptake of opsonized organisms by neutrophils was blocked by a monoclonal antibody specific for the Fc receptor and by immune complexes; these findings suggested that most phagocytosis is mediated by the Fc receptor. Similarly, the uptake of opsonized organisms by human monocytes was inhibited by human monomeric IgG1 and by immune complexes. These results illustrate the role of immune phagocytosis of spirochetes in host defense against Lyme disease.

Animals↗
PubMed1983

Natural Distribution of the Ixodes dammini spirochete.

Spirochetes believed to be the cause of Lyme disease were isolated from white-footed mice and white-tailed deer, the preferred natural hosts of Ixodes dammini, the tick vector. Evidence suggests that deer act as a reservoir of the disease and provide an overwintering mechanism for both spirochetes and adult ticks. Some tick larvae may acquire the spirochete by transovarial passage and the nymphal stage may transmit the disease to humans.

Animals↗
PubMed1983

Spirochetes isolated from the blood of two patients with Lyme disease.

We isolated spirochetes from the blood of 2 of 36 patients in Long Island and Westchester County, New York, who had signs and symptoms suggestive of Lyme disease. The spirochetes were morphologically similar and serologically identical to organisms recently found to infect lxodes dammini ticks, which are endemic to the area and have been epidemiologically implicated as vectors of Lyme disease. In both patients, there was a rise in specific antispirochetal antibodies in paired specimens of serum. We conclude that the l. dammini spirochete has an etiologic role in Lyme disease.

Adult↗
PubMedDate not supplied

Epidemiologic features of Lyme disease in New York.

During 1982, surveillance identified 207 cases of Lyme disease in New York State. Cases were clustered in two geographic areas, eastern Long Island and northern Westchester counties. Symptoms and signs of Lyme disease in cases were consistent with previous reports, with erythema chronicum migrans (ECM) being the most frequently (77 percent) reported sign of disease. Facial palsy was reported in a surprisingly high 18 percent of cases. Of 160 cases whose sera were submitted for Lyme spirochete specific IgG antibody testing, 112 (70 percent) had titers greater than or equal to 64, while 88 (55 percent) had titers greater than or equal to 128. Positive titers were not associated with any single sign or symptom of disease, but were significantly associated with symptom onset or tick bite occurring during the three-month period of June, July, and August. We conclude that the incidence of Lyme disease in New York is much higher than previously recognized. In addition, our data suggest that a serologic test for Lyme-spirochete IgG antibody lacks sensitivity, but can be useful in confirming the diagnosis of Lyme disease when antibody titers are high.

Adolescent↗
PubMedDate not supplied

Prevalence of the Lyme disease spirochete in populations of white-tailed deer and white-footed mice.

The prevalence of the Ixodes dammini spirochete (IDS) in white-tailed deer (Odocoileus virginianus) and white-footed mice (Peromyscus leucopus) was studied on the eastern end of Long Island, New York. Both species commonly occur in a variety of habitats, are preferred hosts of Ixodes dammini, and can harbor the spirochetes in the blood. Each animal was examined for spirochetemia, tick infestation, and IDS infection rates in the ticks that were removed from it. The results obtained suggest that in winter deer can be infected by questing adult I. dammini. Adult ticks apparently are infected through transtadial transmission of spirochetes from subadult ticks which had fed earlier in their life history on infected animals. Deer are important hosts of adult ticks and the IDS in winter and probably are a reservoir host in other seasons. The patterns of spirochete prevalence suggest that deer and mice are reservoirs of the organism and thus are fundamental to the ecology of Lyme disease on Long Island.

Animals↗