Real-time estimation of the hospitalization fatality risk of influenza A(H1N1)pdm09 in Hong Kong.

During the early stage of an epidemic, timely and reliable estimation of the severity of infections are important for predicting the impact that the influenza viruses will have in the population. We obtained age-specific deaths and hospitalizations for patients with laboratory-confirmed H1N1pdm09 infections from June 2009 to December 2009 in Hong Kong. We retrospectively obtained the real-time estimates of the hospitalization fatality risk (HFR), using crude estimation or allowing for right-censoring for final status in some patients. Models accounting for right-censoring performed better than models without adjustments. The risk of deaths in hospitalized patients with confirmed H1N1pdm09 increased with age. Reliable estimates of the HFR could be obtained before the peak of the first wave of H1N1pdm09 in young and middle-aged adults but after the peak in the elderly. In the next influenza pandemic, timely estimation of the HFR will contribute to risk assessment and disease control.

From observation to aetiology: a case report of a twin fetus-in-fetu and a revisit of the known rarity.

A baby girl presented with an antenatal diagnosis of a retroperitoneal tumour. Postnatal imaging suggested that this mass contained two fetiform structures with spine and long bone formation. This teratomatous mass was completely excised at 3 weeks of age. Histology was consistent with twin fetuses-in-fetu, revealing two fetiform masses each with an umbilical cord connecting to a common placenta-like mass. Despite a difference in the weight of the twin fetuses-in-fetu, the level of organogenesis was identical and corresponded to fetuses of 10 weeks of gestation. Each mass had four limbs, intact skin, rib cage, intestines, anus, ambiguous genitalia, primitive brain tissue and a spine with ganglion cells in the cord. Although considered a mature teratoma in the current World Health Organization classification, the theory of formation from multiple pregnancies has been commonly implied in more recent literature. The true aetiology of this rare condition remains unclear.

Voiding urosonography with second-generation ultrasound contrast versus micturating cystourethrography in the diagnosis of vesicoureteric reflux.

Vesicoureteric reflux has been associated with paediatric urinary tract infection. Fluoroscopic micturating cystourethrography (MCU) has been the gold standard of diagnostic test for decades; however, it has been criticized owing to its lower detection rate and radiation dose to children. Therefore, new radiation-free reflux imaging modalities have been developed, in which ultrasound-based contrast-enhanced voiding urosonography (ceVUS) is a good example. However, ultrasonography has been considered as an operator-dependent examination. Therefore, our study aimed to examine the inter-observer agreement of this sonographic technique, which has not been evaluated before. Moreover, the second-generation ultrasound contrast SonoVue has been recently marketed, and the data on its efficacy on intravesical use in ceVUS is relatively scarce. Thus, we also aimed to investigate the diagnostic performance and safety profile of SonoVue-enhanced VUS in the diagnosis of vesicoureteric reflux. Our prospective comparative study compared the diagnostic performance of ceVUS with MCU in young children presenting with first episode of urinary tract infection. We performed sequential ceVUS and MCU examinations in 31 patients (62 pelvi-ureter units). Perfect inter-observer agreement (Cohen's kappa statistics = 1.0, p < 0.001) was achieved in ceVUS, suggesting its good reliability in reflux detection and grading. Using MCU as reference, ceVUS had 100 % sensitivity and 84 % specificity and carried higher reflux detection rate than MCU (p < 0.001). There was no complication encountered. Conclusion: Voiding urosonography is a reliable, sensitive, safe and radiation-free modality in the investigation of vesicoureteric reflux in children. It should be incorporated in the diagnostic algorithm in paediatric urinary tract infection.

Clinical severity of human infections with avian influenza A(H7N9) virus, China, 2013/14.

Assessing the severity of emerging infections is challenging because of potential biases in case ascertainment. The first human case of infection with influenza A(H7N9) virus was identified in China in March 2013; since then, the virus has caused two epidemic waves in the country. There were 134 laboratory-confirmed cases detected in the first epidemic wave from January to September 2013. In the second epidemic wave of human infections with avian influenza A(H7N9) virus in China from October 2013 to October 2014, we estimated that the risk of death among hospitalised cases of infection with influenza A(H7N9) virus was 48% (95% credibility interval: 42-54%), slightly higher than the corresponding risk in the first wave. Age-specific risks of death among hospitalised cases were also significantly higher in the second wave. Using data on symptomatic cases identified through national sentinel influenza-like illness surveillance, we estimated that the risk of death among symptomatic cases of infection with influenza A(H7N9) virus was 0.10% (95% credibility interval: 0.029-3.6%), which was similar to previous estimates for the first epidemic wave of human infections with influenza A(H7N9) virus in 2013. An increase in the risk of death among hospitalised cases in the second wave could be real because of changes in the virus, because of seasonal changes in host susceptibility to severe infection, or because of variation in treatment practices between hospitals, while the increase could be artefactual because of changes in ascertainment of cases in different areas at different times.

Aminoglycoside nephrotoxicity in obstructive jaundice.

PURPOSE: Although it is known that liver disease predisposes to aminoglycoside nephrotoxicity, specific features of such disease that may predispose to aminoglycoside-induced renal injury have not been identified. We sought to identify such features. PATIENTS AND METHODS: We undertook a retrospective review of the charts of 42 consecutive patients with biliary obstruction and/or cholangitis who had received more than three doses of an aminoglycoside. RESULTS: Comparison of patients in whom aminoglycoside nephrotoxicity did and did not develop revealed no differences in age, race, sex, dose, and duration of aminoglycoside therapy; mean peak and trough aminoglycoside levels; initial pre-treatment levels of serum creatinine, aspartate transaminase, alkaline phosphatase, or albumin; or prothrombin time. The initial pre-treatment serum bilirubin level was higher in the patients in whom aminoglycoside nephrotoxicity developed (12.2 +/- 8.8 mg/dl versus 3.4 +/- 3.2 mg/dl, p less than 0.01). Aminoglycoside nephrotoxicity occurred in eight patients (19 percent): in seven of 15 patients (47 percent) with an initial bilirubin value greater than 5.0 mg/dl, but in only one of 27 patients (4 percent) with an initial bilirubin value below 5.0 mg/dl (p less than 0.01). The pre-treatment bilirubin level correlated with the change in creatinine during aminoglycoside therapy (n = 42, r = 0.66, p less than 0.01). CONCLUSION: Aminoglycosides should probably be avoided in patients with biliary obstruction and a high serum bilirubin level.

Percutaneous-endoscopic biliary stenting in patients with occluded surgical bypass.

PURPOSE: The purpose of this investigation was to test the feasibility of using a recently developed technique of placing internalized biliary stents into patients who have had reobstruction after initial surgical bypass. PATIENTS AND METHODS: Seven men and three women, 46 to 85 years of age (eight with pancreatic carcinoma, one with metastatic colon, and one with metastatic ovarian carcinoma), all had reobstruction after initial surgical bypass palliation. Subsequent attempts to place stents via endoscope failed in five patients; a pair of 7-Fr stents placed in one patient failed to drain well. Endoscopic stenting in four patients was not even attempted because of severely distorted anatomy. Nine of the 10 patients then had successful internal stent placement by a combined percutaneous-transhepatic and peroral-endoscopically guided technique. RESULTS: One of these nine placeable stents failed to drain well and the patient died 8 days later with massive tumor. Seven showed a significant decrease in bilirubin levels and improved quality of life. Two of these had sepsis that responded to antibiotics. Life span ranged between 11 days and 10 months, with one patient still alive; no deaths were directly due to stents. CONCLUSION: A combined transhepatic-peroral technique of placing internalized biliary stents can be expected to result in repalliation in a majority of patients with reobstruction after earlier surgical bypass and in whom subsequent attempts at endoscopic placement of stents have failed or in whom tumor growth prevents undertaking the endoscopic approach.

Percutaneous endoscopic gastrostomies: a prospective evaluation and review of the literature.

The results of the first 55 consecutive percutaneous endoscopic gastrostomies (PEGs) that were performed over an 18-month period in a tertiary care center are presented. We followed these cases prospectively to assess the morbidity, mortality, staff acceptance, short-and long-term complications, and cost effectiveness of the technique. Fifty-one (93%) were successful with no mortality. Long-term morbidity included 6/55 (11%) tube extrusions; 5/55 (9%) cellulitis around the catheter site; 5/55 (9%) aspiration pneumonias; and 2/55 (3.6%) clogged tubes requiring replacement. Morbidity was considered minor and easily dealt with in all but five instances (9%) where more prolonged treatment was required. A review of the literature including other techniques used for percutaneous gastrostomy is also presented. It is concluded that percutaneous gastrostomies are relatively safe, cost-effective, and should be given first consideration for long-term enteral therapy in appropriate patients.

Volvulus of the small bowel: an uncommon complication after laparoscopic cholecystectomy.

We report here two patients with volvulus of the small bowel after laparoscopic cholecystectomy (LC). There has been only one case report of a similar condition after LC in the English literature; the patient had malrotation of the midgut. Both patients we are reporting had previous pelvic surgery resulting in intraabdominal adhesions. Volvulus had occurred along an axis between the mesenteric attachment and the adhesion to the parietal peritoneum of the involved loop of small bowel. The creation of pneumoperitoneum could conceivably allow rotation to occur. One patient presented with signs of peritonitis from a gangrenous segment of small bowel. The other presented with continued abdominal pain after surgery. Definitive diagnosis was made only at laparotomy. Previous surgery is considered a relative contraindication to LC, although the incidence of morbidity and conversion to open procedure appear not to be influenced by previous surgery. Surgeons should be aware of volvulus as a complication after LC in patients who had previous abdominal surgery.

Complications of endoscopic gastrostomy: pneumoperitoneum and volvulus of the colon.

Pneumoperitoneum caused by percutaneous gastrostomy usually follows a benign clinical course, but led to progressive volvulus of the ileocolic segment in the patient described here. This article explains relationships between pneumoperitoneum after surgical or endoscopic procedures and volvulus involving the intraperitoneally mobile intestinal loops.

Terminal ileitis associated with Blastocystis hominis infection.

We report on the previously unobserved clinical presentation of terminal ileitis secondary to Blastocystis hominis in a 37-yr-old white male. When the patient was treated with metronidazole, the symptoms improved and the radiographic abnormalities resolved. We believe that this is the first well-documented instance of terminal ileitis secondary to B. hominis.

Use of oral GoLytely solution in relief of refractory fecal impaction.

Constipation and fecal impaction are common disorders with multiple treatment options. We describe the use of GoLytely oral solution in 10 patients admitted to a community hospital and referred to a single gastroenterologist for fecal impaction refractory to conventional medical treatment. Seven women and three men received enemas, bisacodyl suppositories, and digital fragmentation either solely or in combination prior to the administration of GoLytely oral solution. The patients had no clinical and radiological evidence of bowel obstruction. All had underlying cardiovascular problems. Their mean age was 78.1 years (range 49-100 years). GoLytely oral solution (Braintree Laboratories, Inc.) was administered at a rate of 100 ml/hr per orem to three patients, via nasogastric tube in six patients, and via gastrostomy tube in one patient. All 10 patients were able to regularly pass feces and show radiographical colorectal clearing within 6.0 to 57.25 hr (mean 23.60 hr). No significant complications were observed. Eight patients were discharged from the hospital within 24 hr of termination of treatment while two patients remained for unrelated medical conditions. GoLytely oral solution effectively relieved fecal impaction in 10 patients refractory to conventional medical treatment.

Silicone-covered metal stents: an in vitro evaluation for biofilm formation and patency.

Self-expanding metal stents are being used more commonly to prevent biliary tract obstruction. Silicone-covered self-expanding metal stents (Wallstent, Schneider, Inc.) have been developed to prevent tumor ingrowth. Biofilm formation and occlusion material in silicone-covered self-expanding metal stents compared to standard polyethylene stents were examined in an in vitro model. Matched pairs of polyethylene and silicone-covered metal stents were perfused with infected bile for 8, 12, and 16 weeks at a rate of 0.5 cc/min at 37 degrees C. Two reservoirs fitted with silicone-covered metal stents had ampicillin/sulbactam added and were perfused for 16 weeks. The stents were then analyzed by scanning electron microscopy and light microscopy for biofilm formation and presence of occlusion material. The two ampicillin/sulbactam-treated stents showed no biofilm formation. Biofilm was seen on all of the remaining stents. There was a difference in occlusion thickness between the 8- and 16-week polyethylene stents, and no difference between the biofilm thickness at 8, 12, or 16 weeks in the silicone-covered metal stents. Silicone-covered self-expanding metal stents will likely extend patency rates in malignant obstructive jaundice by providing a larger lumen for bile flow and allowing cyclical antibiotics to prevent bacterial biofilm formation.

Percutaneous-endoscopic biliary stent placement: a clinician's perspective.

When it becomes necessary to relieve obstructive biliary jaundice, many alternatives are entertained by the physician, the patient and the family. This article describes percutaneous-endoscopic biliary stent placement from this gastrointestinal clinician's point of view, taking into account the previously utilized efforts of surgery, radiology and endoscopy. It will serve as a reference for all those who choose our method when the need to relieve biliary obstruction is encountered.

Severe hypokalemia in thyrotoxic periodic paralysis.

Thyrotoxic hypokalemic periodic paralysis is an uncommon but sometimes fatal disease in which early recognition and therapy may prevent untoward complications. The case of a 26-year-old Chinese man who presented to the emergency department with rapidly progressive profound weakness and severe hypokalemia (serum potassium, 1.2 mEq/L) is presented. The patient required endotracheal intubation, ventilatory assistance, and intravenous potassium administration. Emergency medical evaluation and management of this entity are discussed.

Infectious diarrhea secondary to Enteromonas hominis.

A patient with persistent abdominal cramps and diarrhea was found to be infected with Enteromonas hominis. A thorough search to detect coinciding infection with other pathogens was unrevealing. Treatment with metronidazole resulted in resolution of the patient's symptoms and eradication of E. hominis from the stool, suggesting E. hominis as the causal organism. Although this flagellate has been classified as a non-pathogen, this case suggests that it should be considered as an occasional pathogen.

Inhibition of biliary endoprostheses occlusion by ampicillin-sulbactam in an in vitro model.

An important first step in stent occlusion is the formation of a bacterial biofilm. This is followed by deposition of granules similar to that found in brown pigment stones. Previous in vitro models for studying occlusion have used synthetic biles without bilirubin or pooled human bile, which is limited in supply. Our aim was to develop a new in vitro model of stent occlusion with porcine gallbladder bile and then, with the model, assess whether ampicillin-sulbactam can prevent biofilm formation and thus occlusion. Sterile porcine gallbladder bile was contaminated with Escherichia coli then divided into eight reservoirs, four of which then received ampicillin-sulbactam. The bile was then circulated through 10F polyethylene stents. Bile was changed weekly for 8 weeks. In the stents that were untreated, biofilm and sludge were seen in all four, whereas the four ampicillin-sulbactam-treated stents had no biofilm when viewed by electron microscopy. Furthermore, the levels of calcium, cholesterol, and bilirubin in the reservoirs decreased significantly in the untreated bile as compared with the treated bile (p < 0.05). In this in vitro model, the losses of calcium, cholesterol, and bilirubin are likely caused by deposition of granules into the biofilm matrix. Ampicillin-sulbactam can prevent biofilm formation if used continuously.

Reliability of balloon-mesh cytology in detecting esophageal carcinoma in a population of US veterans.

A catheter, equipped with a terminal balloon covered with nylon mesh, was developed to study the reliability of abrasive cytology for the diagnosis of esophageal carcinoma. Eighty-seven balloon cytology analyses were attempted in 82 subjects. Four patients were unable to swallow the balloon. In the 78 successful attempts, the initial diagnoses were: esophagitis (34) and esophageal carcinoma (13), established by endoscopic examination and histologic sampling; and normal esophagus (31) confirmed histologically in 25. The remaining 6 controls were younger than 40 years old, without any significant history of smoking, drinking and esophageal symptoms. For esophageal carcinoma, the sensitivity of balloon cytology was 91% and the specificity was 94% with four false-positives. Balloon cytology was generally well-tolerated and easily performed. This method is now being tested for screening high-risk patients for esophageal carcinoma.

Heterotopic gastric mucosa in the duodenum: radiographic findings.

Heterotopic gastric mucosa in the duodenal bulb was detected by endoscopic examination in 25 adult patients and was confirmed by biopsy in 17 of these patients. The endoscopic findings were correlated with the radiographic features of the lesion on upper gastrointestinal barium studies. On radiographs, this entity usually presented as clusters of 1- to 3-mm plaques raised above the smooth and featureless duodenal mucosa; this was seen in 17 (68%) of 25 patients. A less frequent finding was patches of coarse nodular mucosa with superficial erosions or an ulcer crater (five cases [20%]). The heterotopic gastric mucosa was visible as polypoid masses in two patients and as prominent areae gastricae covering the base of duodenal bulb in another.

Clinical significance of concurrent hepatitis B surface antigen and antibody positivity.

Over a period of 30 months, 64 patients with concurrently positive hepatitis B surface antigen (HBsAg) and antibody (anti-HBs) were identified at two institutions. When all assays were considered, 23.9% of HBsAg-positive individuals exhibited anti-HBs. Both persistent HBsAg/anti-HBs positivity and variable changes in antigen or antibody status were observed among the 36 patients with follow-up beyond six months. When compared to a control group, these patients did not exhibit differences in risk factors for acquiring hepatitis B or in clinical and histological diagnoses. Concurrent HBsAg and anti-HBs was present at detection in 25 patients, while antibody appeared in the remaining 11 subjects. Subsequently, it was undetectable in seven of these 36 patients; no clinical changes occurred at the time of acquisition or loss of the antibody. The titer of the antibody was below 10 mIU/ml in 75% of these individuals. In 10 patients, the subtype of HBsAg was ad, while the anti-HBs was anti-y. Concurrent HBsAg and anti-HBs is a pattern frequently observed throughout the spectrum of hepatitis B-related events. The heterotypic antibody in these patients is of a low titer, and its appearance or disappearance is not associated with changes in the clinical course; simultaneous HBsAg/anti-HBs positivity does not appear to reflect a distinct clinical entity.

Hepatic dysfunction after repeated isoflurane administration.

Isoflurane, a halogenated volatile anesthetic, has not been associated with a distinct hepatic injury syndrome, as has halothane. Previous cases of suspected isoflurane-induced hepatotoxicity have been reported but questioned. We report the case of a patient without previous liver disease who developed repeated episodes of hepatitis after repeated exposures to isoflurane. Although no biopsy study was conducted, the temporal relationships illustrated in this case strengthen the argument for isoflurane-induced hepatotoxicity.