Dennis J Baumgardner

Geographic information system analysis of blastomycosis in northern Wisconsin, USA: waterways and soil

Geographic information systems (GIS) are powerful tools for investigating the ecogeography of environmentally acquired infections. GIS technology was used to geocode and map cases of blastomycosis, by household, of human and dog residents of Vilas County, Wisconsin, USA. Human case households (n = 136) were from a comprehensive street address registry 1979--2001; human controls were 200 random-number selected households from 2001 county tax records. Dog cases (n = 116) were from a consecutive street address registry from a private veterinarian practice, Eagle River; dog controls were 200 random-number selected addresses from the 2001 total practice registry. Where geocoding was not available from existing maps, home sites were visited and geocoded using a handheld global positioning system (n = 61). Waterway characteristics were obtained from the Wisconsin Department of Natural Resources GNIS database, soil type data from the USDA. Data were analysed with chi-square and Mann-Whitney tests; cluster analysis with CrimeStat II software. A disproportionate number of human and dog cases were associated with waterways of the western Eagle River area. Human and dog cases were more commonly near waterways < 500 m elevation (more nutrient rich) (P < or =0.001 for both) and were associated with sands (prone to drought) (P < or = 0.01 for both). When the nearest waterway was a lake, case addresses were more commonly near lakes with <7.6 m maximum depth (more lake mixing) (P <0.05, humans and dogs) but mean depth, type and size of lakes did not differ from controls. Further studies are needed to clarify the nature of these associations.

Attempted isolation of Blastomyces dermatitidis from native shrews in northern Wisconsin, USA

The precise ecological niche of Blastomyces dermatitidis is unknown. The related dimorphic fungus, Paracoccidioides brasiliensis, has been isolated from South American ground-dwelling insectivorous armadillos. We attempted to isolate Blastomyces from shrews, North American ground-dwelling insectivores that have been shown to harbor Histoplasma capsulatum in endemic areas. Forty-seven masked shrews (Sorex cinereus) and 13 northern short-tailed shrews (Blarina brevicauda) were collected in endemic areas of northern Wisconsin and Michigan using pitfall traps. Specimens were collected between 1998 and summer 2002, stored frozen, then necropsied. Cultures of nasopharynx, lungs, liver, spleen and large and small bowel were placed on yeast extract phosphate agar with one or two drops of ammonium hydroxide. Cultures for Blastomyces were negative from all 60 shrews and two deer mice (Peromyscus maniculatus) and three southern red-backed voles (Clethrionomys gapperi), which were trapped inadvertently. Histological examination of 36 of these specimens revealed no Blastomyces yeast forms. Northern Wisconsin shrews do not appear to be carriers of B. dermatitidis.

Stinging Nettle: the Bad, the Good, the Unknown

Stinging nettle (Urtica dioica) is native to most of the United States. It has a characteristic description and distribution in the environment. Physical contact with numerous tiny needlelike hairs present on leaves and stems of this plant may result in a contact urticarial dermatitis due to chemical and mechanical irritation triggered by skin penetration of the hairs. The manifestations are self-limited in humans and may be treated by washing the skin, topical preparations and oral antihistamines. Explanation of the natural history of these encounters to the patient is helpful in reducing the sometimes significant anxiety. Preparations and extracts of stinging nettle have been proposed for treatment of a variety of inflammatory and other disorders including osteoarthritis, benign prostatic hypertrophy, allergic rhinitis and asthma, bleeding problems and diabetes. While in vitro studies have shown that stinging nettle possesses a number of potentially beneficial anti-inflammatory and modulating properties, beneficial effects have often not been confirmed by well-designed clinical trials. Further study, perhaps with novel types of extracts, are needed to determine the clinical utility of this plant in human inflammatory-related conditions and diabetes mellitus. (J Patient-Centered Res Rev. 2016;3:48-53.)

Freshwater Fungal Infections

Fungal infections as a result of freshwater exposure or trauma are fortunately rare. Etiologic agents are varied, but commonly include filamentous fungi and Candida. This narrative review describes various sources of potential freshwater fungal exposure and the diseases that may result, including fungal keratitis, acute otitis externa and tinea pedis, as well as rare deep soft tissue or bone infections and pulmonary or central nervous system infections following traumatic freshwater exposure during natural disasters or near-drowning episodes. Fungal etiology should be suspected in appropriate scenarios when bacterial cultures or molecular tests are normal or when the infection worsens or fails to resolve with appropriate antibacterial therapy.

Use of Urine Antigen Testing for Blastomyces in an Integrated Health System

Purpose Blastomycosis, an endemic fungal infection, mimics many other diseases. We explored the use of Blastomyces urine antigen (BuAg), reportedly the most sensitive noninvasive test, in clinical practice and compared it to other noninvasive tests. Methods A total of 836 BuAg tests performed on unique patients (first test only) at one large integrated health system from June 2013 to May 2016 were retrospectively reviewed to examine test characteristics and demographic features. Of these, 100 cases from 2015, a year containing a large local blastomycosis outbreak, were randomly selected for detailed analysis. Results Demographics for the BuAg-tested population: mean age 54.9 years, 55.0% male, 78.9% white, 213 zip codes represented. Test results were positive in 49 of 836 (5.9%, across 43 zip codes); 16 of the 49 (32.7%) stemmed from the 2015 outbreak. BuAg-positive patients were younger than those who tested negative, even with outbreak subjects removed (48.1 vs 56.7 years, P=0.008); and Asians and males were overrepresented. Sensitivity/specificity/positive predictive value of BuAg test was 87.9%/97.9%/76.3%, respectively, based on 33 culture-positive cases. Only 2 of 20 culture-positive cases were found positive by Blastomyces antibody (Ab) immunodiffusion (ID) test and 0 of the other 18 by Ab complement fixation (CF). Of those with positive BuAg who were co-tested, 16.1% were positive by Ab ID and 3.9% by Ab CF. Histoplasma urine antigen was co-performed with BuAg in 578 patients (69.1%) and positive in 25 (4.3%); 16 of these 25 (64.0%) also were BuAg-positive (ie, known cross-reactivity). Of the 100 patients examined for index illness details, 7 (6 BuAg-positive) were ultimately diagnosed with blastomycosis, 7 other fungal disease, 26 noninfectious lung disease, 22 pneumonia, 5 skin lesions, 6 malignancies, 3 mycobacteria, 11 other, and 1 unknown. Of 100, 12 were tested by BuAg based on symptoms. Conclusions Blastomyces urine antigen is commonly used for work-up of broad differential diagnoses or known exposures. Not adding Ab ID/CF diagnostic tests (

Fungal Infections From Human and Animal Contact

80 each) to the BuAg test saves money without losing sensitivity.

Geographic Distribution of Maternal Group B Streptococcus Colonization and Infant Death During Birth Hospitalization: Eastern Wisconsin

Fungal infections in humans resulting from human or animal contact are relatively uncommon, but they include a significant proportion of dermatophyte infections. Some of the most commonly encountered diseases of the integument are dermatomycoses. Human or animal contact may be the source of all types of tinea infections, occasional candidal infections, and some other types of superficial or deep fungal infections. This narrative review focuses on the epidemiology, clinical features, diagnosis and treatment of anthropophilic dermatophyte infections primarily found in North America. Other human-acquired and zoonotic fungal infections also are discussed in brief.

Disease-Causing Fungi in Homes and Yards in the Midwestern United States

Purpose Maternal group B Streptococcus (GBS) can be transmitted from a colonized mother to newborn during vaginal delivery and may or may not contribute to infant death. This study aimed to explore the geographic distribution and risk factors of maternal GBS colonization and infant death during birth hospitalization. Methods We retrospectively studied mothers with live birth(s) in a large eastern Wisconsin hospital system from 2007 through 2013. Associations between maternal and neonatal variables, GBS colonization and infant death were examined using chi-squared, Mann-Whitney U and t-tests. Multivariable logistic regression models also were developed. Results Study population (N=99,305) had a mean age of 28.1 years and prepregnancy body mass index (BMI) of 26.7 kg/m 2 ; 64.0% were white, 59.2% married, 39.3% nulliparous and 25.7% cesarean delivery. Mean gestational age was 39.0 weeks. Rate of maternal GBS colonization (22.3% overall) was greater in blacks (34.1% vs. 20.1% in whites, P<0.0001), unmarried women (25.5% vs. 20.0% married, P<0.0001), women with sexually transmitted or other genital infections (P<0.0001) and residents of ZIP code group 532XX (P<0.0001), and was associated with increasing BMI (P<0.0001). All predictors of colonization were significant on multivariable analysis. Rate of infant death was 5.7 deaths/1,000 live births (n=558 excluding lethal anomalies and stillbirths) and was negatively associated with maternal GBS colonization (P<0.0001). On multivariable analysis, 532XX ZIP code group, lower gestational age, preterm labor, hyaline membrane disease, normal spontaneous vaginal delivery, hydramnios, oligohydramnios and absence of maternal GBS were associated with infant death. Conclusions Geographic characteristics were associated with infant death and maternal GBS colonization. Further research is needed to determine if increased surveillance or treatment of mothers colonized with GBS decreases the risk of infant demise at birth. (J Patient Cent Res Rev. 2016;3:66-78.)