An analysis of the relationship of host factors to clinical falciparum malaria by multiple regression techniques.

Clinical records of 58 infections with the Vietnam Smith strain of Plasmodium falciparum in human volunteers were studied in order to 1) characterize the clinical course of infections; 2) investigate the effects of race, weight, age, method of induction, and previous malaria experience on the course of infection using methods of multiple regression; and 3) establish whether differences in drug-treatment groups may have influenced the current study results. We found that blacks tolerated infection better than whites, that heterologous as well as homologous strain immunity persists after infection and that these results could not be attributed to differences in treatment. The clinical course of infections with the Vietnam Smith strain of P. falciparum is described.

Empirical treatment of Shigella dysentery with trimethoprim: five-day course vs. single dose.

Fifty-three adults hospitalized with Shigella dysentery were empirically treated with trimethoprim (200 mg) twice/day for 5 days, a single dose of trimethoprim (600 mg), or placebo in a randomized double-blind trial. During the first 24 hr of therapy, there was a reduction in the number of stools in 18/21 (86%) of patients treated with the 5-day regimen (trimethoprim-5) and 13/15 (87%) of patients treated with a single dose (trimethoprim-1), compared with 7/17 (41%) of the placebo group (P less than 0.025, both comparisons). The mean number of stools passed in the first 24 hr of therapy was 10.6, 10.8, and 21.3 stools in the trimethoprim-5, trimethoprim-1, and placebo groups, respectively. The mean (+/- SD) change in number of stools from baseline among treated patients during the first 24 hr was -4.9 (6.6) and -6.3 (6.3) for the trimethoprim-5 and trimethoprim-1 groups, respectively, compared with an increase of +2.4 (14.8) for the placebo group. There was a clinical failure at 48 hr in 9% of the trimethoprim-5 patients and 13% of trimethoprim-1 patients compared with 70% of placebo patients (P less than 0.005, both comparisons). Although we were unable to demonstrate a difference in efficacy between the two dosage schedules of trimethoprim, we conclude that both treatment regimens are effective for the treatment of Shigella dysentery.

Risk of hepatitis B infection among Egyptians infected with Schistosoma mansoni.

Three hundred twenty-four individuals in a farming village located in the Nile Delta of Egypt were serially tested for hepatitis markers and Schistosoma mansoni to determine whether there is an increased risk of hepatitis B in persons infected with schistosomiasis. One-half of the subjects had stools positive for S. mansoni. Thirty-seven percent of the individuals had been infected with hepatitis B, and 3% were chronic HBsAg carriers. No statistical association was found between S. mansoni infection and hepatitis B infection, including chronic hepatitis B. Although there was no evidence of an association between these 2 pathogens, larger nonhospital based studies are needed to resolve this question.

Molecular characterization of Vibrio cholerae O139 isolates from Asia.

In 1992, a serologically novel clone of Vibrio cholerae, designated O139, caused large epidemics of diarrhea in India and Bangladesh. To determine the extent of the spread of V. cholerae O139 worldwide, 484 V. cholerae non-O1 strains isolated from different patients with diarrhea in Thailand, Indonesia, the Philippines, and Peru in 1993 were tested for agglutination in O139 antisera. One hundred fifty-one of these 484 isolates were examined for genes encoding cholera toxin, zonula occlulans toxin, the repetitive sequence 1, and the toxin coregulated pilin A (the V. cholerae virulence gene complex). Thirty-three percent (122 of 364) of V. cholerae non-O1 strains isolated from different patients with diarrhea in Thailand agglutinated in O139 antisera. Ninety-eight percent (120 of 122) of V. cholerae O139 contained the V. cholerae virulence gene complex. None of the 104 V. cholerae non-O1 strains isolated from patients with diarrhea in Indonesia or the 14 strains from patients with diarrhea in the Philippines were serotype O139. Four different ribotypes were found in V. cholerae O139 isolated in Asia. Twenty-three (47%) of 49 Thai O139 strains examined were of different ribotypes than isolates from India and Bangladesh; V. cholerae strains that were not O1 or O139 that were isolated from flies and water in Thailand 11 years previously in 1981 contained the same V. cholerae virulence gene complex found in V. cholerae O1 and O139. This suggests that other unidentified virulence determinants are involved in V. cholerae O139 pathogenesis.

Evaluation of febrile patients in Port Sudan, Sudan: isolation of dengue virus.

One hundred consecutive patients admitted to the Port Sudan Hospital with a temperature greater than or equal to 100 degrees F were evaluated. Enteric fever was diagnosed in 19 patients and malaria in 13. Virologic studies identified 21 cases of dengue infection. One dengue 1 and 17 dengue 2 infections were diagnosed by viral isolation. Three untyped dengue infections were identified serologically. The clinical presentation and course of patients infected with dengue virus were most consistent with classic dengue fever. There was no evidence of hemorrhagic phenomena or shock in any of the dengue-infected patients. Both dengue 1 and 2 must be considered causes of acute fever in East Africa.

Persistent, recurring diarrhea in a colony of orangutans (Pongo pygmaeus) caused by multiple strains of Campylobacter spp.

A colony of 10 orangutans (Pongo pygmaeus) experienced persistent, recurring diarrhea caused by multiple infections with Campylobacter jejuni and C. coli. Infections appeared to have occurred through several mechanisms, including fecal-oral transmission between orangutans, and possibly transmission by houseflies contaminated with the organisms from nearby chicken feces. Among the 14 fecal and environmental C. jejuni isolates, 4 different antibiotic susceptibility profiles were detected; there were also 4 different profiles among the 8 isolates of C. coli. In 5 orangutans, there were back-to-back infections by different strains of C. jejuni, suggesting that a single C. jejuni infection may not confer protective immunity against heterologous strains circulating in the same vicinity. Transmission was effectively interrupted by environmental modifications and a 7-day course of oral erythromycin.

The etiology of diarrhea among American adults living in Peru.

During 1984-1989, 655 diarrheic and 287 nondiarrheic stool specimens from adult U.S. citizens living in Lima, Peru were tested for presence of bacterial enteropathogens. Frequencies of isolation among diarrheic specimens were: Shigella 9.8%; Campylobacter 6.1%; enterotoxigenic Escherichia coli (ETEC) 6.0%; Plesiomonas 2.0%; Salmonella 1.4%; and Vibrio 0.6%. Isolates recovered from non-diarrheic stools were: Shigella 4.5%; Campylobacter 2.1%; Salmonella 1.0%; ETEC 0.7%; Plesiomonas 0.7%; and Vibrio 0.3%. Aeromonas, an unproven cause of diarrhea, was isolated from 9.2% of cases and 3.5% of controls. Disease occurrence was strongly associated with isolation of Shigella, ETEC, Campylobacter, or Aeromonas (p less than or equal to 0.01). During the 6-year period of study, shifts in the dominant phenotypes of Shigella and Campylobacter occurred which may have important implications for vaccine development and intervention strategies.

Enterotoxigenic Escherichia coli and other causes of infectious pediatric diarrheas in Jakarta, Indonesia.

A hospital stool survey of Indonesian children less than 5 years of age determined the prevalence of diarrhea caused by enterotoxigenic Escherichia coli (ETEC) and other bacterial enteropathogens, compared to non-diarrheic control patients. ETEC were the second most frequent cause of diarrhea, isolated from 16 of 194 (8.2%) of patient's stools compared to 2 of 97 (2.1%) of control stools. The highest prevalence was in infants 12 to 23 months of age (17.9%).

The etiology of childhood diarrhea in northern coastal Peru: the 1989 Fuerzas Unidas Humanitarian Civic Action--a model for international and interservice cooperation, community service, and scientific opportunity.

As a humanitarian civic action project, American and Peruvian military medical personnel established a temporary clinic in Dos Palos, Peru. Fecal specimens from 20 diarrheic children and 10 non-diarrheic controls were tested for common agents of diarrhea. Enteropathogens detected in diarrheic stools were enterotoxigenic Escherichia coli (ETEC; 30%), Aeromonas (20%), enteropathogenic E. coli (15%), and Campylobacter (15%). Isolates from control specimens were Aeromonas (10%) and Campylobacter (10%). ETEC-associated diarrhea was more common in this study (30%) than in three similar populations studied in Lima (2-16%). The results suggest that the northern coastal area of Peru is a relatively high-risk area for diarrhea caused by ETEC.

[Arthroplasty of the knee using total condylar prosthesis. Long term results (10 to 17 years) and survival analysis]. / Arthroplastie du genou par prothèse Total Condylar. Résultats à long terme (10 à 17 ans) et analyse de survie.

INTRODUCTION: This study refers to the first 76 Total Condylar knee prostheses that were implanted in 66 patients, with a minimum follow-up of 10 years. MATERIALS AND METHODS: There were 54 women and 12 men with an average age of 65 years (range 45-81). The diagnosis was osteoarthrosis in 63 knees and rheumatoid arthritis in 13. We were able to review 54 prostheses with an average follow-up of 13 years (10-17) using the rating system of the Hospital for Special Surgery and the Survivorship analysis. RESULTS: The results were excellent and good in 72.5 per cent knees and fair and poor in 22 per cent, 3 knees (5.5 per cent) had been revised for deep infection in 2 cases and for aseptic loosening in 1. Pain at rest was absent or mild in all but one patient; walking pain was absent in 32 knees (63 per cent), mild in 12 (23 per cent), moderate in 5 (10 per cent) and severe in 2 (4 per cent). Average range of motion was 89 degrees, ranging from 40 degrees to 120 degrees. A flexion contracture greater 5 degrees was seen in 8 knees (16 per cent). Instability in the frontal plane tested in full extension was more than 5 degrees in 10 patients (19.5 per cent). A significant deterioration of the results occurred in the last 4-5 years, since in 1988 excellent and good results were still 82 per cent. A loss of postoperative alignment of 5 degrees or more was observed in 11 knees: aseptic loosening was identified in 2 of these cases and deformation of the tibial component was seen in 1 knee. In the remaining 8 knees we observed increased lateral instability, compared to the postoperative evaluation. In this group of 8 knees we measured in the AP view the thickness of the tibial component on the lateral and medial side. We found polyethylene wear on the medial side in 4 cases. Ten of the 11 knees with loss of alignment had an early postoperative femoro-tibial axis less than 5 degrees. We observed radiolucent lines in 18 patellar and 27 tibial components. A width greater than 2 mm, correlated to an extension to 5 or more zones, was seen in 3 tibial components with aseptic loosening. Survivorship analysis using aseptic loosening, mechanical failure of the polyethylene and deep infections as end point gave a cumulative success rate at 10 years of 92 per cent% with 95 per cent confidence interval ranging from 85.1 to 98. DISCUSSION: Our study reports a lower percentage of excellent and good results if compared to other series of Total Condylar prosthesis with a comparable follow-up. A significant deterioration of the results occurred in the last years, but this was often not related to the knee itself but to poor general conditions in some patients. In this series there is a relevant number of knees with a post-operative alignment that today we don't consider correct and all the aseptic loosenings occurred in knees with a tibial component positioned in varus. CONCLUSION: Survivorship analysis gave a cumulative success rate comparable with those reported in other studies and confirmed the durability and longevity of this model of prosthesis.

Campylobacter diarrhea in Alexandria, Egypt.

The role of Campylobacter as a cause of bacterial diarrhea in young children in Alexandria, Egypt was investigated. Stools or rectal swabs were collected from 880 children (mean age 9.8 months) presenting to a hospital with the primary complaint of diarrhea and from 1,079 well children (mean age 8.8 months) attending a vaccination clinic. Isolation of Campylobacter was significantly (p<0.0002) more frequent from cases (17.2%) than from controls (6.4%). Campylobacter was isolated from children presenting with diarrhea more frequently than Salmonella (3% isolation rate), Shigella (2% isolation rate), or other bacterial pathogens (1% isolatoin rate). Isolation of Campylobacter was significantly more frequent during the rainy season (p<0.0012). These results implicate Campylobacter as a major bacterial cause of diarrhea for which young children are brought for medical attention in Alexandria, Egypt.

Oral challenge with Aeromonas in protein-malnourished mice.

The lack of an animal model for Aeromonas-associated diarrhoea has hindered progress toward understanding the pathogenesis of this potentially important enteric infection. Protein-malnourished mice were challenged orally with Aeromonas strains to determine if diminished levels of resistance would allow the induction of a diarrhoeal response. The 15 Aeromonas spp. faecal isolates used for challenge included 7 A. caviae, 4 A. hydrophila, 1 A. sobria bv. sobria, and 1 A. sobria bv. veronii from patients with diarrhoea, and 2 A. caviae from healthy volunteers. All had at least 1 known virulence marker, with the exception of 1 strain. Mice on the protein deficient diet had lost an average of 23% of their initial body weight at the time of challenge. Although mice consumed 10(8) cfu per day for a minimum of 4 days, none became ill due to Aeromonas spp. ingestion. Aeromonas spp. were isolated from 75% of faecal cultures obtained 7 days after initial challenge, indicating bowel colonization had occurred.

Modified CAMP test for biogrouping Vibrio cholerae O1 strains and distinguishing them from strains of V. cholerae non-O1.

A modified CAMP test was used to identify 973 Vibrio cholerae isolates by phenotype. Eltor and non-O1 strains were CAMP positive; classical strains were CAMP negative. Sausage-shaped zones of hemolysis of eltor strains were easily distinguished from narrower bands of non-O1 isolates. For O1 isolates, there was 100% agreement between the CAMP test and inhibition by polymyxin B.

[Comparison of Gunther, Filcard and LGM definitive caval filters. Our experience]. / Filtri cavali definitivi Gunther, Filcard e LGM a confronto. Nostra esperienza.

The authors report their experience with 30 caval filters placed throughout 3 years, and compare it with the data from the literature. In 8 patients (26.5%) Gunther filters were used, in 16 cases (53.5%) Filcard filters (4 DF-01 and 12 DF-04) and finally the last 6 patients (20%) were treated with LGM filters. In 18 cases (60%) the filters were positioned through right common femoral vein, whereas in the remaining 12 patients (40%) they were placed through the right internal jugular vein. Early complications were 1 mispositioning (3.3%) with a LGM filter, 2 incomplete opening (6.6%) of Filcard DF-01 filters, 3 significant tiltings (10%) with Filcard DF-04 filters. One patient (3.3%) died one week after the placement of a Gunther filter. The radiologic follow-up, which included controls with conventional radiology, US, cavography, MR and CT revealed no later complications. All the filters exhibited both advantages and disadvantages. Although all the filters commonly in use are effective to prevent pulmonary embolism, further experience is necessary to find out the "ideal" filter.

[Outbreak of paratyphoid fever among Peruvian naval personnel]. / Brote de fiebre paratifoidea entre personal de la marina del Perú.

A retrospective epidemiological study was conducted in connection with an outbreak of paratyphoid fever at a Peruvian naval installation in Callao. The study sought to determine the magnitude of the outbreak, the source of infection, the attack rates, the persistence of bacilli excretion, and the clinical picture of the disease. The source of Salmonella paratyphi B infection had been a meal of chicken and rice served to around 400 members of the naval police. Over a period of three weeks, 21 persons were hospitalized and 52 received outpatient treatment at the naval hospital. In addition, through a questionnaire it was revealed that 86 unreported cases of diarrhea related to the outbreak had occurred. The most common clinical manifestations were fever, headache, weakness, anorexia, abdominal pain, and diarrhea. The general attack rate was 39.8%. In a follow-up survey carried out 37 days after exposure, fecal cultures indicated that 8.5% of the persons affected continued to excrete the microorganism. The high rates of attack and transmission of S. paratyphi B in this outbreak point up the considerable pathogenicity and virulence of some strains of the microorganism and their impact on public health. It is suggested that preventive measures be taken at naval and other similar installations, including the education of workers who handle and prepare food, in order to ensure proper hygiene.

Use of vaginal tampons in sewer surveys for non-O1. Vibrio cholerae.

Vaginal tampons were shown to be a practical alternative to conventional Moore swabs for isolating Vibrio cholerae from sewage. Associated laboratory investigations demonstrated improved isolation of V. cholerae by using 12- or 18-h enrichments in alkaline peptone water, in comparison with 6-h enrichments, when cultures were incubated at ambient temperatures.

Campylobacter diarrhoea and an association of recent disease with asymptomatic shedding in Egyptian children.

A hospital-based case-control diarrhoea survey was conducted in Cairo, Egypt to determine the age-specific frequency of campylobacter infection among diarrhoeic and non-diarrhoeic children aged new born to 5 years. Campylobacter was the most common bacterial enteropathogen isolated from diarrhoeic stools. The overall prevalence of campylobacter isolations was 25.9% from stools of 143 diarrhoeic children compared to 15.2% of 132 non-diarrhoeic control children (P = 0.028) during the 4-month period of study. Children less than 1 year of age were at greatest risk of campylobacter infection with 32.6% of diarrhoeic patients culture positive, compared to 14.3% of controls. Asymptomatic shedding in controls was positively associated with a recent diarrhoeal episode (P = 0.019) and may be an important source of new infections.