Biomedical subjects
Publications and source records attributed to R Steffen.
The cornerstones of a travel health consultation are: information, advice on anti-mosquito measures, vaccinations, malaria chemoprophylaxis and guidelines for presumptive treatment. The art of travel medicine is the ability to focus on the realistic health needs of the traveller whilst leaving aside superfluous information. In this way, unnecessary adverse events, expenses and patient anxiety can be avoided.
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The object of the study was to determine the incidence rate of meningococcal disease in travelers originating in industrialized countries and visiting developing countries. Subjects were intercontinental travelers with meningococcal diseases acquired from 1986 to 1989. Health authorities in 108 countries were contacted; data obtained by postal survey were analyzed. The 56 replying health authorities reported 13 cases of meningococcal disease in tourist or business persons as well as 40 primary and 26 secondary cases in pilgrims in Mecca. The majority of cases were due to serogroup A. The case fatality rate in both groups of patients slightly exceeded 20%. Among the tourists and business persons, several patients had stayed in hotels; in several the onset of symptoms occurred during the flight home. The incidence rate per month of stay was estimated to be 0.4 per million travelers in this group, but 2000 per million in pilgrims to Mecca. Vaccination of pilgrims to Mecca is highly recommended, presently even compulsory. For the usual traveler to endemic countries, the risk of infection abroad seems not to exceed the one at home, thus vaccination may be limited to high-risk groups, such as trekkers.
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The introduction of an active vaccine against hepatitis A, the most frequent of the vaccine-preventable infections in travellers, is an important contribution to travellers' health. Although theoretically the risk of exposure may be minimised by taking hygienic precautions, most travellers in practice remain at considerable risk. As compared to immunoglobulin, vaccine has the advantages of better and long-lasting protection. A double-strength vaccine has been introduced (HAVRIX, 1440 enzyme-linked immunosorbent [ELISA] units [EL.U]) and a single injection will protect from day 14 for 1 year. No significant adverse events have been reported. Questions that remain unanswered are whether travellers leaving before day 14 should receive immune globulin plus vaccine and whether very young travellers should all be immunised.
Bacterial and fungal infections are a major cause of morbidity and mortality after orthotopic liver transplantation. In the immunocompromised host, infections are thought to arise from the gut, which is almost always colonized with potential pathogens. Using oral selective bowel decontamination (SBD), potential pathogens can be eradicated from the gut and infections prevented. In this catamnestic study we have reviewed gastrointestinal colonization, bacterial and fungal infections, and bacterial resistance to standard antibiotics in our first 206 liver transplant patients while under SBD. With few exceptions, gram-negatives were eradicated from the gastrointestinal tract and secondary colonization was inhibited. In spite of unsatisfactory elimination of Candida, probably because nystatin doses were too low, Candida infections were rare (n = 4) and none was fatal. One and two-year survival rates were 93% and 92%, respectively. The bacterial and fungal infection rate was 27.8% with an infection-related mortality of 1.95%. Infections with aerobic gram-positive bacteria prevailed and only 11 gram-negative and 11 fungal infections occurred; among the latter, Aspergillus and Mucor were the most serious and responsible for three of the six deaths in this series. With regard to the development of resistance, we found an increasing number of enterococci and coagulase-negative staphylococci resistant to ciprofloxacin and imipenem, respectively, but unlikely as a consequence of SBD.
The model of orthotopic rat liver transplantation has been a useful tool in transplantation research for two decades. Due to technical problems, the optional hepatic artery anastomosis is not performed in many experiments. Recently developed techniques, however, have made rearterialization a simple procedure. With our technique of cuff rearterialization to the recipient common hepatic artery, in 600 rat liver grafts we achieved high viability, and an early patency rate of 100%. Patency rates after 2 and 21 days were nearly 90%. Cuff rearterialization is simple, rapid to perform, and provides a physiologic model. Compared to strictly venous liver grafts, rearterialized grafts demonstrate improvement in survival, more rapid normalization of liver function parameters, a better preserved liver structure, and less biliary complications. Rearterialization is an important component of a physiologically relevant rat liver transplantation model, and non-specific changes due to arterial ischemia may adversely affect the interpretation of experimental data.
OBJECTIVE: The authors evaluated the complication rate and outcome of side-to-side common bile duct anastomosis after human orthotopic liver transplantation. SUMMARY BACKGROUND DATA: Early and late biliary tract complications after orthotopic liver transplantation remain a serious problem, leading to increased morbidity and mortality. Commonly performed techniques are the end-to-end choledochocholedochostomy and the choledochojejunostomy. Both techniques are known to coincide with a high incidence of leakage and stenosis of the bile duct anastomosis. The side-to-side bile duct anastomosis has been shown experimentally to be superior to the end-to-end anastomosis. The authors present the results of 316 human liver transplants, in which a side-to-side choledochocholedochostomy was performed. METHODS: Biliary tract complications of 370 transplants in 340 patients were evaluated. Three hundred patients received primary liver transplants with side-to-side anastomosis of donor and recipient common bile duct. Thirty-two patients with biliary tract pathology received a bilioenteric anastomosis, and in eight patients, side-to-side anastomosis was not performed for various reasons. Clinical and laboratory investigations were carried out at prospectively fixed time points. X-ray cholangiography was performed routinely in all patients on postoperative days (PODs) 5 and 42. In patients with suspected papillary stenosis, endoscopic retrograde cholangioscopy and papillotomy were performed. RESULTS: One biliary leakage (0.3%) was observed within the early postoperative period (PODs 0 through 30) after liver transplantation. No stenosis of the common bile duct anastomosis was observed during this time. Late biliary stenosis occurred in two patients (0.6%). T tube-related complications were observed in 4 of 300 primary transplants (1.3%). Complications unrelated to the surgical technique, including papillary stenosis (5.7%) and ischemic-type biliary lesion (3.0%), which must be considered more serious in nature than complications of the anastomosis or T tube-related complications, were observed. Papillary stenosis led to frequent endoscopic interventions and retransplantations in 1.3%. CONCLUSIONS: Side-to-side common bile duct anastomosis represents a safe technique of bile duct reconstruction and leads to a low technical complication rate after human orthotopic liver transplantation. Ischemic-type biliary lesion evoked by preservation injury, arterial ischemia, cholestasis, and cholangitis may represent a new entity of biliary complication, which markedly increases the morbidity after human liver transplantation. Therefore, this complication should be the subject of further research.
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This study is a retrospective review of eight pediatric patients with multifocal intestinal Crohn's disease who underwent strictureplasty with or without concomitant bowel resection between January 1978 and April 1992. The patients ranged in age from 9.9 years to 18.5 years. Indications for surgery were partial intestinal obstruction (n = 6), failure of medial therapy or steroid dependence (n = 4), growth failure (n = 2), and enterocutaneous fistula (n = 2). Thirty-six strictureplasties were performed in the eight patients (median, 4.5 strictureplasties per patient; range, 1-12). Bowel resection was performed in six of the eight patients in areas where strictureplasty was not feasible. The mean length of resection was 40 cm (range, 15-82 cm). The only complication was intestinal hemorrhage, which was conservatively managed in two patients. The patients were followed for a mean of 19 months (range, 3-55 months). Five patients had a weight below the fifth percentile prior to surgery. Postoperatively, there was a weight gain in seven patients, including all five patients who were originally below the fifth percentile. A statistically significant weight gain was found when a paired t test analysis was applied to the entire group (p = 0.04). Five of six patients who were on steroid medication at the time of surgery were successfully weaned within 1.5-3 months (mean, 2.3 months) from the time of surgery. Seven of eight patients had relief of their intestinal symptoms. Strictureplasty with small-bowel resection, or perhaps strictureplasty alone, in pediatric patients with multifocal intestinal Crohn's disease can improve gastrointestinal symptoms, promote weight gain, and allow discontinuation of steroid medications.(ABSTRACT TRUNCATED AT 250 WORDS)
Acute pancreatitis is unusual in pediatric patients, and chronic pancreatitis is even less common. Between 1983 and 1988, we diagnosed 24 patients in late childhood and adolescence with chronic pancreatitis. Our review revealed that chronic pancreatitis presents as recurrent abdominal pain in late childhood and adolescence. Individual laboratory and radiological investigations may be normal during acute exacerbations of pain, but the determination of serum amylase and lipase concentrations--combined with ultrasonography--will accurately identify most patients. We found that endoscopic retrograde cholangiopancreatography is a valuable tool in the diagnosis of structural abnormalities. Surgical intervention may reduce symptoms in patients with structural abnormalities. There is a tendency toward decreased frequency and severity of pain as the patients increase in age.
The Swiss Working Group for Health Advice to Travellers regularly publishes its recommendations for malaria prophylaxis and vaccination as supplement to the 'Bulletin' of the Federal Office of Public Health. In this review the strategy with respect to information, to clever behavior abroad, to chemoprophylaxis and immunization prophylaxis is analyzed. A critical evaluation of emergency self-therapy describes remaining questions in particular.
In the present study, a biomechanical in-vitro experimental design for assessing lumbar instability following discectomy had been complemented by computer simulation of the muscular influence. The most impressive changes of the instability parameters chosen, i.e., mobility (flexibility) and neutral zone, occurred in respect of the study movement directions Ty, Tz and Mx (lumbar disc height, anterior/posterior dislocation, and flexion/extension). The influence of the multifidus muscle had enabled the flexion/extension neutral zone changes to be offset. Flexibility (+/- Rx) was found to have been influenced to a minor degree.
Stand-by treatment is the use of anti-malaria drugs carried for self-administration when fever and flu-like symptoms occur and prompt medical attention is not available. This paper aims to review the rationale for the stand-by therapy concept, the range of options available, the factors influencing the choice of therapy and the efficacy and toxicity of the various agents available in the light of ever increasing resistance to conventional drugs. The use of chloroquine as a possible stand-by treatment is limited because of widespread chloroquine resistance and the problem is further compounded by the increasing prevalence of parasites resistant to antifolate/sulpha drug combinations, particularly in South-East Asia and South America. Mefloquine is a promising agent for presumptive malarial treatment with limited foci of drug resistance, notably in Thailand. Mefloquine therapy has been associated with adverse events, mostly minor but with occasional neuropsychiatric events. The use of halofantrine, hitherto often recommended as a stand-by treatment, has been curtailed after recent research reports demonstrated that the drug may cause prolongation of the QTc interval. Current experience with stand-by therapy is limited and studies are in progress to elucidate the exact circumstances under which travellers actually use their emergency medication. Stand-by treatment is an option for clearly defined situations while prophylaxis remains the safest choice for travellers to areas of high transmission.
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Travellers' diarrhea is the most frequently occurring health problem in travellers to tropical and subtropical regions. The main risk factors for this condition are substandard hygiene, contaminated food and drink. Usually the illness begins during the first week of travel and lasts on average four days with mild symptomatology. The causative agent is usually bacterial (40% enterotoxic E. coli), and strict observance of hygiene rules and careful selection of food and drink is an effective strategy to avoid travellers' diarrhea. Prophylactic use of antibiotics is rarely indicated, but self-therapy is of central importance. Adequate oral rehydration is essential, and in uncomplicated cases, antimotility drugs can provide adults with rapid symptomatic relief. Additional antibiotic treatment can be recommended.
There is much confusion over which malaria chemoprophylaxis should be used in areas such as East Africa. We did two consecutive studies between 1985 and 1991 to assess the efficacy and side-effects of malaria chemoprophylaxis in short-term travellers to East Africa. All passengers returning from Kenya to Europe received an in-flight questionnaire and a second one three months later. Any report of documented malaria or of admission to hospital for possible side-effects was verified with the physician. 145 003 travellers completed questionnaires. Among the 139 164 who stayed in East Africa for less than one year, 296 cases of confirmed malaria were reported (275 due to P falciparum). In people who used no chemoprophylaxis, the incidence of falciparum malaria was 1.2% per month. Prophylactic effectiveness was 91% (95% Cl 85 to 94) for mefloquine, 82% (71 to 89) for pyrimethamine and sulfadoxine, 72% (56 to 82) for chloroquine plus proguanil, and 10 to 42% for chloroquine at various doses. Rates of side-effects, which were usually mild, were 18.8% for mefloquine users, 17.1% and 18.6% for chloroquine 300 mg and 600 mg base per week, respectively, 30.1% for chloroquine plus proguanil, and 11.7% for sulfadoxine and pyrimethamine. Mefloquine is significantly more effective than chloroquine plus proguanil for malaria prophylaxis in short-term tourists visiting East Africa and has a tolerance similar to that of chloroquine used alone.
The efficacy and safety of fleroxacin in brief self-treatment of travelers' diarrhea were studied. In The Gambia, 195 tourists with acute diarrhea were randomized in a double-blind, controlled trial into three treatment groups: fleroxacin 400 mg for 1 day, fleroxacin 400 mg daily for 2 days, and placebo. Microbiology of stools was assessed only at recruitment. In the fleroxacin-treated groups, stool consistency was normal in 67% and 71% of the volunteers after 48 hours, as compared to 37% in the placebo group (p < 0.01). The time to total relief of diarrhea and of all symptoms was also significantly shorter in fleroxacin-treated patients. Adverse events, particularly slight neuropsychiatric reactions (headache, insomnia) were more frequent in the fleroxacin-treated groups (p < 0.05). There was no statistically significant difference in efficacy and tolerance if fleroxacin was administered for 1 or 2 days. A single dose of fleroxacin 400 mg may be recommended for the self-treatment of travelers' diarrhea.