Paracoccidioidomycosis in Colombia: an ecological study.

The natural habitat of Paracoccidioides brasiliensis, agent of paracoccidioidomycosis (PCM), remains unknown. This study is aimed at establishing associations between the ecological variables present in all Colombian municipalities and the incidence of PCM. Records of 940 patients were studied and several ecological variables analysed, as well as their association to amount of patients per total rural population in each municipality, determined through a multivariate analysis. All 940 patients came from 216 municipalities (20-3%), out of which, 93 were birthplace and place of long-term residence for 121 patients. The Incidence Rate Ratio (IRR) was determined for these 93 municipalities. The following variables fitted the model: altitude from 1,000 to 1,499 metres above sea level (IRR = 6.37), rainfall from 2000 to 2999 mm (IRR = 2.15), presence of humid forests (Holdridge) (IRR = 1.79) and coffee (IRR = 1.95), tobacco (IRR = 3.59) crops. These results indicate that these municipalities constitute reservareas for P. brasiliensis (Borelli).

Liver abscess caused by Ascaris lumbricoides: case report.

A case is reported of a woman who lived in a rural area with a chronic illness that consisted of weight loss and abdominal pain in the epigastrium and upper right quadrant. The initial diagnosis was a mass in the liver, which was later, demonstrated, both by direct and histological examination, to be an abscess caused by Ascaris lumbricoides. Eggs of Ascaris lumbricoides and abundant Charcot-Leyden Crystals were found.

Iatrogenic Mycobacterium abscessus infection: histopathology of 71 patients.

The histopathology is described of 190 skin biopsies from 71 patients who presented during an epidemic of nodules and abscesses in the periumbilical region and buttocks, secondary to the application of xylocaine injections. Positive cultures for Mycobacterium abscessus were obtained from the specimens and from the xylocaine solution. The severe inflammatory lesions involved the dermis and the hypodermis and had three main histopathological patterns: (i) granulomatous nodular or diffuse inflammation with mixed granulomas in 57 (80%) of the cases; (ii) prevailing abscesses with mild granulomatous reaction in 28 (15%) of the biopsies; and (iii) deep dermal and subcutaneous granulomatous inflammation with no neutrophil component in three (4%) of cases. Bacilli were detected in 51 (27%) of the specimens, frequently forming small clumps at the centre of clear spaces or vacuoles and which were lipid-like structures in 156 (82%) of the abscesses or granulomas. This series represents one of the largest reported outbreaks caused by atypical mycobacteria and in which the source of infection was confirmed. The results emphasize the essential role of skin biopsies in determining the histopathological substrate, in helping to detect the atypical mycobacterial origin and in encouraging the practice of cultures for the identification of micro-organisms.

Iatrogenic outbreak of M. chelonae skin abscesses.

We describe an outbreak of skin lesions due to Mycobacterium chelonae subsp. abscessus associated with injections of lidocaine (lignocaine) given by a 'bioenergetic' (a practitioner of alternative medicine) in Colombia. The lidocaine carpules and the lesions of the patients yielded mycobacteria with identical biochemical characteristics. Using the methodology of Sartwell and a case control design we examined the incubation period and assessed risk factors. Of 667 potentially exposed individuals, a total of 298 patients were interviewed, of whom 232 had skin lesions. The median incubation period was 30.5 days (range 15-59 days). Male sex (OR 2.85, 95% CI 1.26-6.51), increasing age (OR 1.25, 95% CI 1.03-1.53), subcutaneous injection route (OR 3.72, 95% CI 1.09-12.7) and number of injections (OR 1.01, 95% CI 1.00-1.03) were risk factors for disease. To our knowledge, this is the largest reported outbreak of M. chelonae infection, the first in which the organism has been isolated from the putative vehicle of infection, and the first in which the incubation period could be determined.

[Quality of sputum microscopy in the network of tuberculosis bacteriology laboratories in Colombia]. / Calidad de la baciloscopia de esputo en la red de laboratorios de bacteriología de tuberculosis en Colombia.

The objective of this study was to evaluate the technical quality of sputum microscopy carried out for diagnostic purposes in the Network of Tuberculosis Bacteriology Laboratories in Colombia. The National Central Reference Laboratory received 6,529 slides for reexamination from the network of 513 sectional, regional, and local laboratories, which contributed 33.2%, 27.6%, and 39.2%, respectively, of the slides. These included all the positive (3,283) and negative (3,246) smears processed during a 4-month period. The reexamination was carried out by six laboratory workers who did not know the origin of the slides or the original diagnosis. When qualitative problems were detected, a second reexamination was done, which significantly increased the percentage of agreement for both the positive results (93.9%) and the negative (98.7%). Overall, the level of agreement was 96.3%. A significant correlation was found (P < 0.05) between good slide preparation and staining and agreement in the readings, as well as between thin smears, presence of fuchsin precipitates, and deficient coloration and conflicting readings (P < 0.05). The highest percentages of agreement were associated with laboratories that performed the largest number of sputum examinations each month (96.5%), and with readings done by experienced, university-trained bacteriologists (96.6%). It is concluded that indirect technical supervision and ongoing training of laboratory personnel are important determinants of the impact of the tuberculosis control program.

Calidad de la baciloscopia de esputo en la red de laboratorios de bacteriología de tuberculosis en Colombia / Quality of sputum microscopy in the network of tuberculosis bacteriology laboratories in Colombia

El objetivo fue evaluar la calidad técnica de la baciloscopia de esputo realizada con fines diagnósticos en la Red de Laboratorios de Bacteriología de la tuberculosis en Colombia. En el Laboratorio Central Nacional de Referencia se recibieron para relectura 6 529 láminas provenientes de la red de 513 laboratorios seccionales, regionales y locales, los cuales contribuyeron 33,2, 27,6 y 39,2 por ciento de las láminas, respectivamente. Estas representaron todas las baciloscopias positivas (3 283) y la siguiente negativa (3 246) procesadas durante un período de cuatro meses. La relectura estuvo a cargo de seis lectores que desconocían la procedencia de las láminas y el diagnóstico original. Cuando se detectaron discordancias cualitativas, se hizo una segunda relectura que aumentó significativamente las concordancias, tanto de los resultados positivos ((3,9 por ciento) como de los negativos (98,7 por ciento), con una concordancia total de 96,3 por ciento. Se hallo una correlación significativa (P0,05) entre buen extendido y buena coloración y las lecturas concordantes, así como entre extendidos delgados, presencia de precipitados de fucsina y decoloración deficiente y las lecturas discordantes (P0,05). Los porfcentajes de concordancia más altos se relacionaron con los laboratorios que realizan mensualmente el mayor número de baciloscopias (96,5 por ciento), y con las lecturas por bacteriólogos universitarios experimentados (96,6 por ciento). Se concluyed que la supervisión técnica indirecta y la continua capacitación del personal de laboratorio son factores determinantes del impacto del Programa de Control de la Tuberculosis

Calidad de la baciloscopia de esputo en la red de laboratorios de bacteriología de tuberculosis en Colombia / Quality of sputum microscopy in the network of tuberculosis bacteriology laboratories in Colombia

El objetivo fue evaluar la calidad técnica de la baciloscopia de esputo realizada con fines diagnósticos en la Red de Laboratorios de Bacteriología de la tuberculosis en Colombia. En el Laboratorio Central Nacional de Referencia se recibieron para relectura 6 529 láminas provenientes de la red de 513 laboratorios seccionales, regionales y locales, los cuales contribuyeron 33,2, 27,6 y 39,2 por ciento de las láminas, respectivamente. Estas representaron todas las baciloscopias positivas (3 283) y la siguiente negativa (3 246) procesadas durante un período de cuatro meses. La relectura estuvo a cargo de seis lectores que desconocían la procedencia de las láminas y el diagnóstico original. Cuando se detectaron discordancias cualitativas, se hizo una segunda relectura que aumentó significativamente las concordancias, tanto de los resultados positivos ((3,9 por ciento) como de los negativos (98,7 por ciento), con una concordancia total de 96,3 por ciento. Se hallo una correlación significativa (P0,05) entre buen extendido y buena coloración y las lecturas concordantes, así como entre extendidos delgados, presencia de precipitados de fucsina y decoloración deficiente y las lecturas discordantes (P0,05). Los porfcentajes de concordancia más altos se relacionaron con los laboratorios que realizan mensualmente el mayor número de baciloscopias (96,5 por ciento), y con las lecturas por bacteriólogos universitarios experimentados (96,6 por ciento). Se concluyed que la supervisión técnica indirecta y la continua capacitación del personal de laboratorio son factores determinantes del impacto del Programa de Control de la Tuberculosis

Distribution of liposomes in tuberculous mice.

The dynamics of the distribution of liposomes for use as drug carriers for the treatment of tuberculosis is studied. While the free radiolabel injected into mice was rapidly excreted by the kidneys, the same label trapped within liposomes was retained for longer periods in the liver, spleen and lung. There were variations in the distribution and retention times of liposomes of different composition. When the distribution of liposomes in healthy and tuberculous mice was compared, a greater accumulation in the liver, spleen and lungs of healthy mice was observed, although the retention time in tuberculous mice was longer. These findings merit consideration in the design of therapies based on liposome-entrapped drugs as the dynamics of distribution and retention differ between normal and infected animals.

A simple technique for entrapping rifampicin and isoniazid into liposomes.

A method for the preparation of liposomes loaded with rifampicin and isoniazid is described. Optimal conditions were established; the lipid suspension was mixed with the aqueous solution of the drugs and was sonicated in a bath for 30 min at 50 degrees C. The optimum composition tested was phosphatidyl choline, cholesterol and cardiolipin in a molar ratio of 7:2:1. The separation of unloaded drug was performed by centrifugation through three successive Sephadex G-25 columns. The liposomes were multilamellar vesicles with a size ranging from 100-300 nm. The drugs were trapped in concentrations from 6.5-9.5 mg/ml. This method is suitable for preparation of liposomes in small laboratories.

The use of rifampicin and isoniazid entrapped in liposomes for the treatment of Murine tuberculosis.

Liposomes loaded with rifampicin and isoniazid were used experimentally to treat mice with severe tuberculosis. The animals were distributed in four groups. The control group and the group treated with unloaded liposomes showed the severest disease. Both groups showed the lowest accumulated survival, about 50% after 30 days. The numbers of colony-forming-units (CFU) and root specific lung weight (RSLW) were the highest and the histopathology of the lung showed marked diffuse lesions. However, the group treated with unloaded liposomes showed significantly higher growth of M. tuberculosis compared with the control. The group treated with drug and drug loaded liposomes showed a higher survival, about 85% after 30 days, and the lowest values of CFU and RSLW. The lung histology revealed considerably less inflammation which was focal. The parameters evaluated indicated a significantly better response in the group of animals treated with rifampicin and isoniazid entrapped in liposomes.

Abnormal hemoglobins in Northwestern Mexico.

Blood samples from 9,929 individuals in Northwestern Mexico were assayed for abnormal hemoglobins (Hbs). alpha-thal, beta-thal, beta s and beta c traits, as well as rare abnormal Hbs were observed with variable low frequencies (0 to 0.45%). Eight out of eleven rare abnormal Hbs detected so far have been characterized: Three Hb Riyadh, one Hb J Georgia, one Hb Fannin-Lubbock, one Hb Chiapas and two Hb Tarrant. These results suggest that abnormal Hbs do not constitute a regional public health problem and reflect a wide ethnologic heterogeneity.

Detection of hemoglobin alterations in a sample population in northwest Mexico. Preliminary report.

Blood samples from 1,000 individuals seen at the Instituto Mexicano del Seguro Social in northwestern Mexico were assayed by multiple systems (acid, alkaline and neutral electrophoresis, heat, freeze and isopropanol stability and erythrocytic morphology under hypoxia) to detect hemoglobin (Hb) abnormalities. Two beta-thalassemia heterozygotes (0.2 per cent), five Hb S heterozygotes (0.5 per cent) and three probable new Hb variants (0.3 per cent) were identified. These preliminary results give a general idea of the gene frequencies in this population, but do not yet permit the evaluation of the relative advantage of multiple methodology for the detection of abnormal Hbs.