A windy day in a sheep saleyard: an outbreak of Q fever in rural South Australia.

In December 2004, the Department of Human Services investigated an outbreak of Q fever in South Australia. A case-control study tested an association between attending a local saleyard and human illness. A case was defined as a person with clinical illness and evidence of seroconversion or high phase II IgM. Controls were selected from a database of community controls matched on sex, age group and postcode. Matched analysis of the first 15 cases with 45 controls indicated that contracting Q fever was associated with attending the saleyard on one particular day (adjusted odds ratio 15·3, 95% confidence interval 1·7-undefined, P = 0·014). Saleyard conditions were windy and conducive for airborne dispersal of contaminated particles. In total, 25 cases were detected. Of these, 22 cases had attended a local saleyard on the same day. This outbreak suggests cases were probably infected by a single exposure at a saleyard from infected sheep and dust. The investigation resulted in an increase in the local uptake of Q fever vaccination and extension of the Australian national vaccination programme.

Does using potting mix make you sick? Results from a Legionella longbeachae case-control study in South Australia.

A case-control study was performed in South Australia to determine if L. longbeachae infection was associated with recent handling of commercial potting mix and to examine possible modes of transmission. Twenty-five laboratory-confirmed cases and 75 matched controls were enrolled between April 1997 and March 1999. Information on underlying illness, smoking, gardening exposures and behaviours was obtained by telephone interviews. Recent use of potting mix was associated with illness (OR 4.74, 95% CI 1.65-13.55, P=0.004) in bivariate analysis only. Better predictors of illness in multivariate analysis included poor hand-washing practices after gardening, long-term smoking and being near dripping hanging flower pots. Awareness of a possible health risk with potting mix protected against illness. Results are consistent with inhalation and ingestion as possible modes of transmission. Exposure to aerosolized organisms and poor gardening hygiene may be important predisposing factors to L. longbeachae infection.

Reiter syndrome following protracted symptoms of Cyclospora infection.

Two large outbreaks of diarrheal illness associated with Cyclospora cayetanensis, a coccidian parasite, provided an opportunity to evaluate clinical syndromes associated with this enteric pathogen. Reiter syndrome, a triad of ocular inflammation, inflammatory oligoarthritis, and sterile urethritis, has been associated with enteric infections. We describe the first case of Reiter syndrome following protracted symptoms of Cyclospora infection.

Randomized, double-blind study in healthy adults to assess the boosting effect of Vaqta or Havrix after a single dose of Havrix.

A randomized, double-blind, multicenter study was conducted to investigate the boosting effect of Vaqta or Havrix in 537 healthy adults 18-53 years of age who had received a single dose of Havrix either 24 or 52 weeks earlier. Subjects were randomized in a 2 : 1 ratio to receive either Vaqta or Havrix for their second dose of vaccine and followed for clinical reactions for 14 days after dose 2 was administered. Serum samples were collected immediately before dose 2 was administered and again 4 weeks later and evaluated for hepatitis A antibody (modified hepatitis A virus antibody assay). The booster response rate after administration of the second dose of either vaccine was similar (86.1% for Vaqta vs. 80.1% for Havrix). The geometric mean titers were also similar: 3274 mIU/mL (95% confidence interval [CI], 2776-3858) for Vaqta versus 2423 mIU/mL (95% CI, 1911-3074) for Havrix. The proportion of subjects who reported > or =1 injection-site adverse experiences was lower in the patients receiving Vaqta than in those receiving Havrix (36.6% vs. 59.7%; P<.001). The results of this study indicate that a regimen of Havrix followed by Vaqta is generally well tolerated and highly immunogenic.

Omeprazole or ranitidine bismuth citrate triple therapy to treat Helicobacter pylori infection: a randomized, controlled trial in Vietnamese patients with duodenal ulcer.

AIM: To evaluate the effectiveness of triple therapy containing either omeprazole or ranitidine bismuth citrate (RBC) to treat H. pylori infection in Vietnamese duodenal ulcer patients. METHODS: Patients infected with H. pylori were randomized to receive either omeprazole (20 mg b.d.), clarithromycin (500 mg b.d.) and amoxycillin (1 g b.d.) for 10 days (OAC), or RBC (400 mg b.d.), clarithromycin (500 mg b.d.) and amoxycillin (1 g b.d.) for 10 days (RAC). H. pylori eradication and ulcer healing was established by a follow-up oesophagogastroduodenoscopy (EGD) at least 4 weeks after therapy. Side-effects and compliance were assessed. RESULTS: One hundred and four out of 108 (96%) patients with a duodenal ulcer were infected with H. pylori. Eighty per cent of infected patients had detectable CagA IgG antibodies. Fifty-seven patients received OAC and 47 received RAC. OAC eradicated H. pylori in 91 and 86% of patients by per protocol (PP) and intention-to-treat (ITT) analysis, respectively. PP and ITT eradication rates for RAC were 96 and 91%. Ulcer healing at the follow-up EGD was 89% with OAC and 100% with RAC. Side-effects were minor. No patient failed to complete the protocol due to side-effects. CONCLUSION: Triple therapy with either omeprazole or RBC is highly effective in eradicating H. pylori and healing duodenal ulcer in Vietnamese patients.

Cyclosporiasis: clinical and histopathologic correlates.

Although the histopathologic changes associated with Cyclospora cayetanensis infection have been previously described, the histopathology and the appearance of various life cycle stages have not been correlated with severity, stage, and duration of clinical disease. We report a prospective clinical investigation of disease characteristics and histopathologic findings in three otherwise healthy, immunocompetent patients with symptomatic C. cayetanensis infection, the duration of which ranged from 6 to 60 days. Varying degrees of gross and microscopic gastrointestinal inflammation were seen before treatment. An electron-dense phospholipid membrane/myelin-like material was variably present both before and after treatment. The greatest amount of myelin-like material was seen in the patient with prolonged disease. The results of our study suggest that inflammatory changes associated with C. cayetanensis infection may persist beyond parasite eradication. It is intriguing to speculate that the myelin-like material is a marker for persistent inflammation, but further study and confirmation are needed.

Chronic diarrhea in the returned traveler.

The persistence of gastrointestinal symptoms after travel to a developing country is one of the most common and troublesome post-travel illnesses. Few data exist to document the extent of this problem, but anecdotal examples abound among travel medicine practitioners, internists, and gastroenterologists. This article presents an approach to the patient with persistent gastrointestinal symptoms after travel.

Cyclospora infection: a review.

Cyclospora is a coccidian parasite responsible for a syndrome of acute and chronic diarrhoea. The organism first come to worldwide attention in 1990 following the publication of three reports. The largest series of cases and the first clinical description of the illness associated with this organism came from Kathmandu where travellers and expatriates were noted to have prolonged diarrhoea with a previously undescribed organism. The organism has been identified as a coccidian both by observation of sporulation and subsequent molecular phylogenetic analysis. Cyclospora organisms appear as non-refractile double-walled spheres, 8-10 microns in diameter. The organism floats in Sheather's sucrose solution and appears variably red on the modified acid-fast stain. It can also be identified on plain wet mounts. Since its first description, Cyclospora has been noted in an increasing number of countries throughout the world. Water-borne transmission has been implicated in several studies. There is a distinct seasonality in Cyclospora outbreaks and cases. In Nepal, the organism has occurred in virtually identical seasonal outbreaks since 1989. The clinical illness associated with Cyclospora is characterized by diarrhoea, nausea, anorexia and weight loss, which may persist for weeks to months if untreated. Evidence of malabsorption of D-xylose has been noted and small bowel biopsies revealed moderately severe villous atrophy and crypt hyperplasia. Successful treatment with trimethoprim-sulfamethoxazole has been identified, but to date no alternative treatment exists for the sulfa allergic patient.

Pathologic changes in the small bowel in nine patients with diarrhea associated with a coccidia-like body.

OBJECTIVE: To confirm a suspected small-bowel injury in patients with a syndrome of protracted diarrhea associated with a coccidia-like body (CLB). DESIGN: Investigation of an epidemic including a case-control study. SETTING: Outpatient clinic in Kathmandu serving primarily the tourist and expatriate community in Nepal. PATIENTS: Nine patients with diarrhea with at least one stool specimen that was positive for the presence of a CLB and seven noninfected volunteer controls. MEASUREMENTS: Clinical data, microscopic examination of stool, bacteriologic and viral studies on submitted stool specimens, upper gastrointestinal endoscopy including duodenal aspiration and microscopy, small-bowel biopsy with subsequent light and electron microscopy. RESULTS: Endoscopic evidence of inflammation of the distal duodenum was present in five of nine patients with CLB and in none of the seven controls. All nine patients with CLB were noted to have histologic evidence of small-bowel injury, which included acute and chronic inflammation, surface epithelial disarray, and varying degrees of villous atrophy and crypt hyperplasia. One of the seven controls had similar pathologic findings and developed CLB-related diarrhea 5 days later. The other controls had normal distal duodenal histologic results. The organism was found in two of nine duodenal aspirates but was not present in the preserved biopsy specimens as determined by light or electron microscopy. CONCLUSIONS: The pathologic basis of CLB-associated diarrhea appears to be small-bowel injury whose cause remains to be elucidated.

Management of Chlamydia trachomatis genital infections: reported practices of primary care physicians.

OBJECTIVE: To determine the knowledge of primary care physicians about Chlamydia trachomatis genital infection and its management. DESIGN: Self-administered questionnaire comprising direct questions and hypothetical cases. PARTICIPANTS: All 108 general and family practitioners on the north shore of Vancouver were sent the questionnaire; 79 (73%) responded. RESULTS: There was a reasonable level of knowledge in many areas, particularly among the physicians who had graduated more recently than the others. Virtually all stated that they have access to chlamydial diagnostic testing, and most indicated that they test for chlamydial infection at least occasionally. However, many of the respondents failed to consider that youths in their practice may be sexually active, and only 28% knew that women 15 to 19 years of age have the highest reported rates of chlamydial infection. Many of the physicians were confused about syndromes that are or are not associated with C. trachomatis infection; this indicated the possibility of inappropriate testing and treatment decisions. If they had to test for C. trachomatis in a prepubescent girl 34% reported that they would obtain a specimen from the endocervix, a technique that is inappropriately invasive. When presented with a positive test result many of the respondents failed to consider the possibility of a false-positive result. Fortunately all of the physicians were well informed about correct treatment regimens for C. trachomatis infection, although many did not realize how effective they really are. In the case of a young man with suspected or proven gonorrhea or a young female outpatient with pelvic inflammatory disease, only 19% and 20% respectively stated that they would prescribe a regimen appropriate for both penicillinase-producing Neisseria gonorrhoeae and C. trachomatis. Many of the respondents had not heard of management guidelines, and fewer still reported that they consult them. CONCLUSIONS: Despite the availability of several sets of guidelines there appear to be important gaps in the knowledge and practice of many primary care physicians with respect to genital infections. Since the preparation of guidelines is time-consuming and expensive, further work should be done to evaluate their impact and to address their limitations.

Human renin gene: structure and sequence analysis.

The complete protein precursor of human kidney renin has been determined from the sequence of cloned genomic DNA. The gene spans 12 kilobases of DNA and is interrupted by eight intervening sequences. The nine regions (exons) encoding the protein were mapped with a mouse renin cDNA probe, synthetic oligonucleotide probes, and by hybridization of genomic restriction fragments to a 1600-nucleotide human kidney mRNA. The predicted 403-amino acid preprorenin consists of mature renin and a 66-residue amino-terminal prepropeptide. The DNA sequence 5' to the first exon indicates the location of a transcriptional promoter (T-A-T-A-A-A) for a mRNA encoding preprorenin. An additional transcriptional promoter site is located within the first intron, which, if used, would express a shortened nonsecreted prorenin. The structure of the human renin gene is similar to that of human pepsinogen, a closely related aspartyl protease enzyme. This observation suggests that renin and pepsinogen have a common evolutionary origin.

Mucor mediastinitis.

A 69-year-old man with lymphocytic leukemia presented with fever, a pericardial friction rub, widening of the mediastinum, and left pleural effusion. Atrial fibrillation, refractory hypotension and acute paraplegia punctuated his hospital course. Invasion of the mediastinum, myocardium, mediastinal, coronary and spinal arteries with mucormycosis was present at post-mortem examination.