Human pseudoterranovosis, an emerging infection in Chile.

Fifteen cases of human pseudoterranovosis are reported for Chile, representing an emerging parasitic infection in this country caused by larvae of the nematode Pseudoterranova sp. Our observations also included an outbreak of pseudoterranovosis in 3 of 4 individuals who shared the same raw fish dish (cebiche). Most of the cases occurred in adult patients. The main source of infection was from consumption raw or fried marine fish, including hakes (Merluccius australis or Merlucciuts gayi), pomfret (Brama australis), Inca scad (Trachurus murphvi), and corvina (Cilus gilberti). Seasonal distribution showed most of the cases to occur in fall and spring. Parasite larvae were isolated from the mouths of most of the patients after they reported a pharyngeal tickling sensation, coughing, vomiting, or a foreign body in the mouth or throat.

[Detection of fecal Cryptosporidium parvum antigens using an ELISA technique]. / Detección de antígenos fecales de Cryptosporidium parvum mediante técnica de ELISA.

ELISA techniques using monoclonal antibodies have been recently developed for the detection of Cryptosporidium parvum fecal antigens. The aim of this work was to compare the yield of these ELISA techniques with Ziehl-Nielsen and Safranin stains in formaldehyde-salt fixed samples. One hundred five fecal samples of patients with acute diarrhea were studied. Forty-seven samples did not contain Cryptosporidium and ELISA was negative. Also, ELISA was positive in 52 or 58 samples that contained Cryptosporidium (89.6%); the samples with false negative results contained scanty oocysts. Seven intensely positive Paf-fixed stool samples from AIDS patients with chronic diarrhea, were not reactive to ELISA. There was a good correlation between visually and mechanically read samples and there were no false positives. It is concluded that ELISA cannot be used in Paf-fixed samples and has a lower sensitivity that the stained commonly used for the diagnosis of cryptosporidiosis.

[Diagnosis of cryptosporidiosis: a comparative study on Ziehl-Neelsen and safranine stain methods]. / Diagnóstico de la cryptosporidiosis: estudio comparativo de las tinciones Ziehl-Neelsen y safranina.

Infection by cryptosporidium causes acute or chronic diarrhea in immunocompetent or immunosuppressed patients respectively. We compared the Ziehl-Nielsen and the safranine stains in 604 stool samples from children with acute diarrhea. Sensitivity for safranine (96%) and for Ziehl-Nielsen (88%) was not significantly different. Given the simplicity and low cost of the safranine stain, this is proposed as a routine method for the investigation of infection by cryptosporidium.

[Chagas' disease: an evaluation of serodiagnosis at blood banks in the endemic areas of Chile]. / Enfermedad de Chagas: evaluación del serodiagnóstico en bancos de sangre de zonas endémicas en Chile.

Blood transfusion is one mechanism leading to transmission of Chagas disease. An evaluation of the serologic method used to survey donors in 55 blood banks located in endemic areas was attempted. From 47 responders, 29 (62%) showed complete correlation with the standard used, 16 (34%) showed only 50% correlation and 2 were not possible to evaluate. Most errors were due to an incorrect evaluation of the negative standard serum, whereas the positive one was correctly diagnosed as such in 96% of cases.

[Indirect immunofluorescence with monoclonal antibodies in the diagnosis of Pneumocystis carinii. Preliminary report]. / Inmunofluorescencia indirecta con anticuerpos monoclonales en el diagnóstico de Pneumocystis carinii. Informe preliminar.

We compared traditional methods based on argentic metamine and toluidine blue staining vs recently introduce techniques based on immunofluorescence for monoclonal antibodies in the diagnosis of P. carinii. Fifty samples were analyzed: 29 (58%) were negative by all method. Of the remaining 21.72% were positive for immunofluorescence, 67% for argentic and 48% for toluidine blue staining. Thus, immunofluorescence techniques represent an improvement in the ability to diagnose infection by P carinii.

[Cryptosporidium parvum in patients with chronic diarrhea and AIDS: diagnosis by means of indirect immunofluorescence with monoclonal antibodies]. / Cryptosporidium parvum en pacientes con diarrea crónica y SIDA: diagnóstico mediante immunofluorescencia indirecta con anticuerpos monoclonales.

The diagnosis of cryptosporidiosis is difficult when oocyst elimination is poor as occurs in AIDS patients. Aiming to improve the diagnosis, 144 fecal samples coming from AIDS patients with diarrhea, were studied using indirect immunofluorescence with anti-Cryptosporidium monoclonal antibodies. The results were compared with Ziehl Neelsen and safranine stainings. Twenty three samples (15.9%) were positive for Cryptosporidium with at least one of the three methods. Sensitivities were 78.3% for immunofluorescence, 86.9% for Ziehl Neelsen and 91.3 for safranine stainings. The specificity of the three methods was 100%. It is concluded that immunofluorescence does not improve the diagnostic accuracy of cryptosporidiosis and its high cost precludes its use in routine laboratories.

[External quality control of the parasitological diagnosis of Cryptosporidium parvum]. / Control de calidad externo en el diagnóstico parasitológico de Cryptosporidium parvum.

Between 1991 and 1994, eight external quality assessments of Cryptosporidium parvum infection diagnosis were performed. Stool specimens were sent to 74 laboratories, to be stained and examined. In 40 laboratories (54.1%), the diagnosis was correct in all evaluations, whereas in 34 (46%), the diagnosis disagreed with the parasitology reference laboratory in one occasion or more. The mean correlation of diagnoses with the reference laboratory was 88% (range 79-96%). Ninety-three percent of negative samples and 87% of positive samples were correctly diagnosed. These figures are similar to those obtained abroad. These results lead to the development of a quality control network for the diagnosis of Cryptosporidium parvum infections along the country, aiming to improve its reliability.

[Microsporidiosis in patients with chronic diarrhea and AIDS, in HIV asymptomatic patients and in patients with acute diarrhea]. / Microsporidiosis en pacientes con diarrea crónica y SIDA, HIV asintomáticos y pacientes con diarrea aguda.

Microsporidia are intracellular protozoa that mainly affect AIDS patients and chronic diarrhea, caused by the strains Enterocytozoon bieneusi and Septata intestinalis, is the most common clinical manifestation. The diagnosis is made in intestinal biopsies, however the recently developed trichromic stain with chromotrope 2R, is able to detect microsporidia in stools and has a good correlation with the biopsy. Using this technique, we studied 43 asymptomatic HIV infected subjects, 89 AIDS patients with chronic diarrhea and 186 patients with acute diarrhea as controls. Thirty-three percent of patients with AIDS, 16.3% of HIV infected subjects and none of the individuals with acute diarrhea had microsporidia in their stools (p < 0.05). In 15 patients with AIDS we detected intermitted stool microsporidia shedding; this finding should encourage repetitive examinations in negative cases. The trichromic stain for microsporidia is proposed as a routine test in AIDS patients with diarrhea.

[Comparison of 2 treatment schemes to eradicate Helicobacter pylori]. / Comparación de dos esquemas de tratamiento para erradicar Helicobacter pylori.

INTRODUCTION: Anti secretory drugs, antimicrobials and bismuth salts are used with variable success to eradicate Helicobacter pylori. AIM: To assess the effectiveness and rates of reinfection of two therapeutic modalities H pylori infection in adult patients with duodenal ulcer or non ulcer dyspepsia. METHODS: During upper gastrointestinal endoscopy, 5 antral and 2 fundic biopsies were obtained and sent for microbiological and anatomopathological study. Patients infected with Helicobacter pylori were randomly assigned to receive during two weeks omeprazole 20 mg od plus amoxicillin 500 mg tid (group A) or bismuth subsalicylate 260 mg bid, metronidazole 250 mg tid and amoxicillin 500 mg tid (group B). A new endoscopy with antral and fundic biopsies was performed to all patients four weeks after discontinuing treatment and six months later to those in whom H pylori was eradicated. RESULTS: Eighty patients (40 in each treatment group) completed the treatment and follow up. H pylori was eradicated in 22 patients of group A (55%) and 28 of group B (70%). Minor adverse effects were reported by 5 patients in group A (12%) and 11 in group B (27.5%). Six months later, reinfection was documented in 12 patients of group A and 8 of group B (54% and 30% of those with successful treatment respectively). Ten of twenty five patients with duodenal ulcer had reinfections, but there was only one ulcer relapse. CONCLUSIONS: These two treatment modalities have similar results.

[New records of human diphyllobothriasis in Chile (1981-1992), with a case of multiple Diphyllobothrium latum infection]. / Registro de nuevos casos de difilobotriasis humana en Chile (1981-1992), incluido un caso de infección múltiple por Diphyllobothrium latum.

Fifteen new human cases of diphyllobothriasis in Chile are reported, one of them a multiple case of infection by Diphyllobothrium latum. Five scolices and 28 m of strobila were recovered after treatment with Niclosamide in a male adult patient with multiple infection. In other 5 cases, after treatment, only one worm was recovered in each person and all corresponded to D. latum species; worms measured between 2.9 to 11.0m. In 9 cases, only the eggs of parasites were reported in the coprological exam. Thirteen cases were determined in the lakes area from south of Chile where infection by plerocercoids in salmonids is very frequent and the persons consume smoked and raw ("cebiche") fishes.

Association of primary Pneumocystis carinii infection and sudden infant death syndrome.

To delineate clinical and histological features of the first Pneumocystis carinii infection affecting the immunocompetent host, P. carinii-specific histological stains were performed on autopsy lung specimens from 534 consecutive pediatric patients (those with AIDS and malignancies were excluded) in Santiago, Chile. P. carinii clusters were found in 4 (25%) of 16 infants who died of no apparent cause at arrival to the emergency department, and in 10 (2.9%) of 342 infants who died of multiple conditions at the hospital (P=.002, Fisher's exact test). This prompted us to analyze additional series of infants with sudden infant death syndrome (SIDS). In 161 additional SIDS cases, 47 (35.1%) of 134 infants from Chile and 4 (14.8%) of 27 infants from Oxford, United Kingdom, were found to have P. carinii clusters in the lungs. The quantity of P. carinii cysts was small compared with the numbers seen in immunocompromised hosts with P. carinii pneumonitis. This study provides histological evidence that primary P. carinii infection is associated with SIDS.