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Biomedical subjects

D D Juranek

Publications and source records attributed to D D Juranek.

At least 37 records · Page 2Linked to original sources
PubMed1993

Babesiosis in Washington State: a new species of Babesia?

OBJECTIVE: To characterize the etiologic agent (WA1) of the first reported case of babesiosis acquired in Washington State. DESIGN: Case report, and serologic, molecular, and epizootiologic studies. SETTING: South-central Washington State. PATIENT: A 41-year-old immunocompetent man with an intact spleen who developed a moderately severe case of babesiosis. MEASUREMENTS: Serum specimens from the patient were assayed by indirect immunofluorescent antibody (IFA) testing for reactivity with seven Babesia species and with WA1, which was propagated in hamsters inoculated with his blood. A Babesia-specific, ribosomal-DNA (rDNA) probe was hybridized to Southern blots of restriction-endonuclease-digested preparations of DNA from WA1, Babesia microti, and Babesia gibsoni. Serum specimens from 83 family members and neighbors were assayed for IFA reactivity with WA1 and B. microti. Small mammals and ticks were examined for Babesia infection. RESULTS: The patient's serum had very strong IFA reactivity with WA1, strong reactivity with B. gibsoni (which infects dogs), but only weak reactivity with B. microti. DNA hybridization patterns with the rDNA probe clearly differentiated WA1 from B. gibsoni and B. microti. Four of the patient's neighbors had IFA titers to WA1 of 256. The tick vector and animal reservoir of WA1 have not yet been identified, despite trapping 83 mammals and collecting 235 ticks. CONCLUSIONS: WA1 is morphologically indistinguishable but antigenically and genotypically distinct from B. microti. Some patients elsewhere who were assumed to have been infected with B. microti may have been infected with WA1. Improved serodiagnostic and molecular techniques are needed for characterizing Babesia species and elucidating the epidemiology of babesiosis, an emergent zoonosis.

Adolescent↗
PubMed1993

American cutaneous leishmaniasis in U.S. travelers.

OBJECTIVE: To characterize the exposures and practices of U.S. travelers who acquired cutaneous leishmaniasis in the Americas and to highlight problems they encountered in seeking medical care from U.S. physicians. DESIGN: A retrospective review of Centers for Disease Control and Prevention Drug Service records and a telephone survey of patients. PATIENTS: Fifty-nine civilian U.S. travelers with American cutaneous leishmaniasis for whom the Drug Service released sodium stibogluconate between 1 January 1985 and 30 April 1990; 58 travelers (98%) were interviewed. MAIN MEASUREMENTS: Travel destination, exposure duration, knowledge about leishmaniasis, and time from noticing skin lesions to release of drug. RESULTS: Overall, travelers acquired leishmaniasis in as many as 14 countries; 33 of 59 travelers (56%) were infected in Mexico or Central America. Twenty-seven travelers (46%) were conducting field studies and 23 (39%) were tourists, visitors, or tour guides. At least 15 persons (26% of the 58 interviewed travelers) were in forested areas for 1 week or less; at least 6 of these persons had a maximum exposure of 2 days. Ten persons (17%) were home at least 1 month before they noticed skin lesions. Patients consulted from one to seven physicians (mean, 2.1 physicians) before leishmaniasis was diagnosed. Overall, the median time from noticing lesions to the release of drug was 112 days (range, 13 to 1022 days); however, the median was only 55 days for 13 patients (22%) unusually knowledgeable about leishmaniasis and was a maximum of 60 days for 16 patients (28%) (including 7 of the 13 unusually knowledgeable patients) who generally consulted physicians exceptionally knowledgeable about infectious and tropical diseases. CONCLUSIONS: Travelers to forested areas in Mexico and Central and South America and their physicians need to be educated about the risk for acquiring leishmaniasis even during short stays, as well as about effective preventive measures; and appropriate medical management [corrected].

Adolescent↗
PubMed1993

Increased exposure to cryptosporidia among dairy farmers in Wisconsin.

Cryptosporidium infection is an important cause of diarrhea in humans and livestock; no effective therapy is known. A self-administered questionnaire and an ELISA were used to assess the risk of exposure to cryptosporidia among 70 dairy farmers and 50 who were not dairy farmers in Wisconsin. Dairy farmers (44.3%) were more likely to be seropositive for cryptosporidia than were other persons (24.0%; relative risk = 1.9). Among dairy farmers, age > or = 50 and use of a canister method of milking were associated with seropositive status. Among persons who were not dairy farmers, feeding or milking cows was associated with being seropositive. These findings suggest that dairy farmers and other persons who have contact with cattle are at greater risk of Cryptosporidium infection than are persons who do not have such contact. Identification and avoidance of farming practices associated with Cryptosporidium infection may reduce the risk of infection among dairy farmers.

Adult↗
PubMed1993

Laboratory-acquired malaria, leishmaniasis, trypanosomiasis, and toxoplasmosis.

Because of renewed interest in parasitic diseases, increasing numbers of persons in clinical and research laboratories have the potential for exposure to parasites and therefore are at risk for acquiring parasitic infections. In this review of laboratory-acquired parasitic infections, we concentrate on protozoan diseases that frequently have been reported to be laboratory acquired: malaria, leishmaniasis, trypanosomiasis (American and African), and toxoplasmosis. These diseases can be severe, even fatal, and may be difficult to diagnose. Many laboratorians who have acquired these diseases did not recall having had an accident. Of those with recognized accidents, needlestick injuries were the most common. Laboratories should have established protocols for handling specimens that may contain viable organisms and for responding to laboratory accidents.

Animals↗
PubMed1993

Recent trends in the prevalence and distribution of schistosomiasis in the Nile delta region.

In 1983, a survey of 71 villages in the Nile delta demonstrated that the overall prevalence of Schistosoma mansoni and S. haematobium infections was 39% and 5%, respectively. Recent increased availability of praziquantel, combined with Egyptian Ministry of Health-sponsored media efforts to educate the public about schistosomiasis, prompted us to determine the current status of S. mansoni and S. haematobium infections in the delta and evaluate any changes that may have occurred since the previous survey. The same villages that participated in the 1983 survey were resampled in 1990. Stool and urine samples were requested from all occupants over the age of two years in a 5% sample of houses within each village. Stool (Kato) thick smears and urine sediments were read qualitatively at the rural health station. Field-prepared Kato smears and a 20% sample of urine specimens were forwarded to the Ministry of Health Laboratory, where quantitative readings were also performed. Analysis of samples obtained from 17,310 persons revealed that S. mansoni prevalence had decreased to 23% and that S. haematobium prevalence had decreased to 3% (P < 0.001). The highest levels of schistosome infection were found in governates located in the eastern section of the delta. The observed changes in the prevalence of S. mansoni and S. haematobium suggest that control measures are having a favorable impact on schistosomiasis transmission in this region.

Adolescent↗
PubMed1992

Diloxanide furoate for treating asymptomatic Entamoeba histolytica cyst passers: 14 years' experience in the United States.

Diloxanide furoate is used for treating asymptomatic or mildly symptomatic persons who are passing cysts of Entamoeba histolytica. The Centers for Disease Control (Atlanta) released this drug for 4,371 treatment courses from 1977 through 1990. Of the 2,815 report forms (64%) returned, 656 adverse effects were reported for 390 treatment courses (14%); they included flatulence (260), diarrhea or cramping (100), nausea (93), headache (17), disorientation or dizziness (9), and diplopia (4). During 1984-1990 uniform collection of data allowed more detailed analysis of toxicity and efficacy; fewer adverse effects were reported for persons aged 20 months to 10 years than for persons aged greater than 10 years (6 of 206 [3%] vs. 89 of 763 [12%], relative risk = 0.27, 95% confidence interval = 0.12 less than relative risk less than 0.61). Parasitological cures were achieved during 497 (86%) of the 575 treatment courses (52%) administered to asymptomatic persons who were passing cysts, who had received a full 10-day treatment course, and for whom results of a follow-up stool examination (greater than or equal to 14 days post-treatment) were available. Diloxanide furoate is safe and effective for treating asymptomatic persons who are passing E. histolytica cysts and may be particularly well tolerated in children.

Adolescent↗
PubMed1992

Improved stool concentration procedure for detection of Cryptosporidium oocysts in fecal specimens.

Epidemiologic and laboratory data suggest that coprodiagnostic methods may fail to detect Cryptosporidium oocysts in stool specimens of infected patients. To improve the efficacy of stool concentration procedures, we modified different steps of the Formalin-ethyl acetate (FEA) stool concentration technique and evaluated these modifications by examining stool samples seeded with known numbers of Cryptosporidium oocysts. Because these modifications failed to improve oocyst detection, we developed a new stool concentration technique that includes FEA sedimentation followed by layering and flotation over hypertonic sodium chloride solution to separate parasites from stool debris. Compared with the standard FEA procedure, this technique improved Cryptosporidium oocyst detection. The sensitivities of the two concentration techniques were similar for diarrheal (watery) stool specimens (100% of watery stool specimens seeded with 5,000 oocysts per g of stool were identified as positive by the new technique, compared with 90% of stools processed by the standard FEA technique). However, the most significant improvement in diagnosis occurred with formed stool specimens that were not fatty; 70 to 90% of formed stool specimens seeded with 5,000 oocysts were identified as positive by the new technique, compared with 0% of specimens processed by the standard FEA technique. One hundred percent of formed specimens seeded with 10,000 oocysts were correctly diagnosed by using the new technique, while 0 to 60% of specimens processed by the standard FEA technique were found positive. Similarly, only 50 to 90% of stool specimens seeded with 50,000 oocysts were identified as positive by using the standard FEA technique, compared with a 100% positive rate by the new technique. The new stool concentration procedure provides enhanced detection of Cryptosporidium oocysts in all stool samples.

Acetates↗
PubMed1991

Acute giardiasis: an improved clinical case definition for epidemiologic studies.

In June 1983, an outbreak of waterborne giardiasis occurred in a group of 93 university students and faculty participating in a geology field course in Colorado. All cases occurred in one subgroup of persons who were heavily exposed to untreated stream water on a field trip, and the risk of illness was strongly related to the amount of untreated stream water consumed. The median incubation period from a brief exposure to the first symptom was 7 days. The authors compared symptoms and stool sample results among 31 Giardia-positive persons in the exposed group and 36 Giardia-negative participants in an unexposed group to assess several case definitions for acute giardiasis. Diarrhea, abdominal cramps, flatulence, foul-smelling stools, nausea, excessive tiredness, bloating, anorexia, and chills were each significantly more common in the first group than in the second. A giardiasis case definition of 5 days or more of diarrhea--the definition used in many epidemiologic studies of giardiasis--had a specificity of 100 percent but a sensitivity of only 32.2 percent compared with a definition based on results of stool examinations. When a case was defined as an illness lasting 7 days or more, with a combination of two or more of six symptoms (diarrhea, flatulence, foul-smelling stools, nausea, abdominal cramps, and excessive tiredness), sensitivity rose to 73 percent, with a specificity of 88 percent. Such a case definition may be an improvement over that of 5 days of diarrhea, especially in outbreaks where there is good laboratory documentation that Giardia is the etiologic agent. The definition should be validated in other outbreaks and in situations where giardiasis must be distinguished from gastrointestinal disease caused by other agents.

Colorado↗
PubMed1991

Giardia lamblia and Cryptosporidium infections in child day-care centers in Fulton County, Georgia.

Risk factors for the introduction, spread and persistence of Cryptosporidium and Giardia lamblia infections in child day-care centers are not well understood. In 1989 and 1990 stool specimens were obtained from 292 diapered children attending 17 randomly selected day-care centers in Fulton County, GA; 8 (2.7%) children in 2 centers were infected with Cryptosporidium and 21 (7.2%) children in 7 centers were infected with Giardia. In 1986 the prevalence of Cryptosporidium and Giardia in these same centers had been 0.4 and 11.0%, respectively; the prevalence of Cryptosporidium, but not Giardia, increased significantly (P = 0.04) between 1986 and 1989 to 1990. Risk factors for Giardia infection included day-care attendance for greater than 3 months, the presence of toddlers in the classroom and the presence of other children in the household. Day-care centers with a Giardia-positive child in 1986 were not more likely to have an infected child in 1989 to 1990. Cryptosporidium, like Giardia, may be endemic in day-care centers in Fulton County.

Child Day Care Centers↗
PubMed1991

Evaluation of a commercially available enzyme-linked immunosorbent assay for Giardia lamblia antigen in stool.

The lack of a quick, simple, and inexpensive diagnostic test has limited the ability of public health officials to rapidly assess and control outbreaks of Giardia lamblia in child day-care centers. We evaluated the performance of a commercially available enzyme-linked immunosorbent assay (ELISA) for the detection of a G. lamblia-associated antigen in stool. Stool specimens were collected from the diapers of 426 children attending 20 day-care centers, fixed in 10% Formalin and polyvinyl alcohol, and examined by microscopy by Formalin concentration and trichrome staining techniques. Specimens were also tested visually and spectrophotometrically by ELISA. Of 99 tests positive by microscopy, 93 were visually positive by ELISA (sensitivity, 93.9%). Of 534 tests negative for G. lamblia by microscopy, 32 (6.0%) were ELISA positive. However, on the basis of examination of multiple specimens from the same child, none of these could be considered false-positive ELISAs; the specificity of the ELISA was therefore 100%. The sensitivity of both microscopy and ELISA improved as the number of specimens per child increased. An optical density value of greater than 0.040 was 98.0% sensitive and 100% specific for G. lamblia. This ELISA, which appeared to be more sensitive for G. lamblia than did microscopic examination of stool, should be useful as an epidemiologic tool, particularly in day-care settings, and may also have a role in confirming clinical diagnoses of giardiasis.

Animals↗
PubMed1991

Threshold of detection of Cryptosporidium oocysts in human stool specimens: evidence for low sensitivity of current diagnostic methods.

To determine the minimum number of Cryptosporidium oocysts that can be detected in stool specimens by diagnostic procedures, stool samples seeded with known numbers of Cryptosporidium parvum oocysts were processed by the modified Formalin-ethyl acetate (FEA) stool concentration method. FEA concentrates were subsequently examined by both the modified cold Kinyoun acid-fast (AF) staining and fluorescein-tagged monoclonal antibody (immunofluorescence [IF]) techniques. Oocysts were more easily detected in watery diarrheal stool specimens than they were in formed stool specimens. For watery stool specimens, a 100% detection rate was accomplished at a concentration of 10,000 oocysts per g of stool by both the AF staining and IF techniques. In formed stool specimens, 100% of specimens seeded with 50,000 oocysts per gram of stool were detected by the IF technique, whereas 500,000 oocysts per g of stool were needed for a 100% detection rate by AF staining. Counting of all oocysts on IF slides indicated a mean oocyst loss ranging from 51.2 to 99.6%, depending on the stool consistency as determined by the FEA concentration procedure. Our findings suggest that the most commonly used coprodiagnostic techniques may fail to detect cryptosporidiosis in many immunocompromised and immunocompetent individuals.

Animals↗
PubMed1991

Use of pooled formalin-preserved fecal specimens to detect Giardia lamblia.

Three formalin-preserved fecal specimens from the same child attending a child-care center were pooled and compared with the three separate individual specimens by a single microscopic examination of concentration sediment for Giardia lamblia. The sensitivity of the pooled system was 100% when two or more individual specimens were positive and 88% when only one individual specimen was positive. The organism density in a single specimen was not a factor of whether the pool of specimens was positive or negative. Nearly half of the pools that contained positive specimens had only one of three specimens with positive results, reinforcing the need for multiple stool examinations when diagnosing G. lamblia infections.

Animals↗
PubMed1991

Waterborne-disease outbreaks, 1989-1990.

For the 2-year period 1989-1990, 16 states reported 26 outbreaks due to water intended for drinking; an estimated total of 4,288 persons became ill in these outbreaks. Giardia lamblia was implicated as the etiologic agent for seven of the 12 outbreaks in which an agent was identified. The outbreaks of giardiasis were all associated with ingestion of unfiltered surface water or surface-influenced groundwater. An outbreak with four deaths was attributed to Escherichia coli O157:H7, the only bacterial pathogen implicated in any of the outbreak investigations. An outbreak of remitting, relapsing diarrhea was associated with cyanobacteria (blue-green algae)-like bodies, whose role in causing diarrheal illness is being studied. Two outbreaks due to hepatitis A and one due to a Norwalk-like agent were associated with use of well water. Eighteen states reported a total of 30 outbreaks due to the use of recreational water, which resulted in illness for an estimated total of 1,062 persons. These 30 reports comprised 13 outbreaks of whirlpool- or hot tub-associated Pseudomonas folliculitis; 13 outbreaks of swimming-associated gastroenteritis, including five outbreaks of shigellosis; one outbreak of hepatitis A associated with a swimming pool; and three cases of primary amebic meningoencephalitis caused by Naegleria. The national surveillance of outbreaks of waterborne diseases, which has proceeded for 2 decades, continues to be a useful means for characterizing the epidemiology of waterborne diseases.

Communicable Diseases↗
PubMed1991

Results of testing for intestinal parasites by state diagnostic laboratories, United States, 1987.

We analyzed results of 216,275 stool specimens examined by the state diagnostic laboratories in 1987; parasites were found in 20.1%. Percentages were highest for protozoans: Giardia lamblia (7.2%), Entamoeba coli and Endolimax nana (4.2% each), Blastocystis hominis (2.6%), Entamoeba histolytica (0.9%), and Cryptosporidium species (0.2%). Identifications of Giardia lamblia increased broadly from the 4.0% average found in 1979, with 40 states reporting increases and seven decreases. Most states that identified Giardia in more than 9% of specimens were located around the Great Lakes or in the Northwest. Seasonally, Giardia identifications increased in the summer and fall, especially in northern states. The most identified helminths were nematodes: hookworm (1.5%), Trichuris trichiura (1.2%), and Ascaris lumbricoides (0.8%). Other less commonly identified helminths included Clonorchis and Opisthorchis species (0.6%), Strongyloides stercoralis (0.4%), Hymenolepis nana (0.4%), Enterobius vermicularis (0.4%), and Taenia species (0.1%). Tape tests for Enterobius, reported for 35 states, were positive for 11.4% of 9,597 specimens. Nine states (California, Colorado, Hawaii, Idaho, New Jersey, Oregon, Rhode Island, Washington, Wisconsin) reported hookworms in more than 2% of specimens; none were states traditionally associated with indigenous transmission. Cryptosporidium diagnoses, reported by 25 of 49 states, were recorded for the first time in a national survey and showed no marked regional clustering. The Giardia data revealed changes in rates of identification and in geographic patterns compared with state laboratory data collected a decade earlier (1976-1978).

Feces↗