RESUMEN
When intrafamilial transmission of hepatitis B virus (HBV) occurs, a virus with the same characteristics interacts with diverse hosts' immune systems and may thus result in different mutations to escape immune pressure. In this study, the HBV genomic characterization was assessed longitudinally after intrafamilial transmission using nucleotide sequence data of phylogenetic and mutational analyses, including those obtained by deep-sequencing for the first time. Furthermore, HBeAg-anti-HBe profile and variability of HBV core-derived epitopes were also evaluated. Strong evidence was obtained from intrafamilial transmission of HBV genotype D1 by phylogenetic inferences. HBV isolates exhibited high degree (~99%) of genomic conservation for almost 20 years, when patients were persistently HBeAg positive with normal amino transferase levels. This identity remained high among immune-tolerant siblings. In contrast, it diminished significantly (P = 0.02) when the mother cleared HBeAg (immune clearance phase). By deep-sequencing, the quantitative analysis of the dynamics of basal core promoter (BCP) (A1762T, G1764A; A1766C; T1773C; 8-bp deletion; and other) and precore (G1896A) variants among HBV isolates from family members exhibited differences during the follow-up. However, only those from the mother showed amino acid variations at core protein that would impair their MHC-II binding. Hence, when intrafamilial transmission occurs, HBV was highly conserved under the immune-tolerant phase, but it exhibited mutations more frequently during the immune clearance phase. The analysis of the HBV BCP and precore mutants after intrafamilial HBV transmission contributes to a better understanding of how they evolve over time.
Asunto(s)
Salud de la Familia , Variación Genética , Virus de la Hepatitis B/clasificación , Virus de la Hepatitis B/inmunología , Hepatitis B Crónica/inmunología , Hepatitis B Crónica/virología , Tolerancia Inmunológica , Adolescente , Niño , ADN Viral/genética , Transmisión de Enfermedad Infecciosa , Femenino , Genotipo , Virus de la Hepatitis B/genética , Hepatitis B Crónica/transmisión , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Mutación , Filogenia , Homología de SecuenciaRESUMEN
Polycystic echinococcosis due to Echinococcus vogeli is a rare parasitic infection that occurs in rural areas of Central and South America. Only molecular identification performed on formalin-fixed paraffin-embedded liver tissue samples gave an unequivocal diagnosis of this disease in a Paraguayan immigrant in Argentina.
Asunto(s)
Equinococosis/diagnóstico , Equinococosis/parasitología , Echinococcus/clasificación , Echinococcus/aislamiento & purificación , Emigrantes e Inmigrantes , Anciano , Animales , Anticuerpos Antihelmínticos/sangre , Argentina , Western Blotting , Echinococcus/genética , Histocitoquímica , Humanos , Inmunoglobulina G/sangre , Hígado/parasitología , Masculino , Técnicas de Diagnóstico Molecular , Paraguay , Patología Molecular , Radiografía Abdominal , Tomografía Computarizada por Rayos XRESUMEN
Prevalence rates of hepatocellular carcinoma (HCC)-associated hepatitis B virus (HBV) pre-S mutants among most genotypes are still lacking. In this study, viral (sub)genotypes of 70 Argentine nucleotide sequences (33 newly obtained) were determined by phylogenetic analysis, and the presence of such mutants was assessed in the American continent for the first time. Nucleotide substitutions of the pre-S2 start codon were observed in 10% of the HBV/A2 sequences. Ten per cent of the HBV/A2 and 12.5% of the HBV/F1b - but none of HBV/F4 - exhibited a deletion in the pre-S1/pre-S2 region. The contribution of these variants to liver cirrhosis (LC) and/or HCC development among HBV/F and HBV/A isolates deserves further prospective clinical studies.
Asunto(s)
Carcinoma Hepatocelular/virología , Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/genética , Hepatitis B/virología , Neoplasias Hepáticas/virología , Precursores de Proteínas/genética , Adolescente , Adulto , Secuencia de Aminoácidos , Argentina , Carcinoma Hepatocelular/complicaciones , ADN Viral/genética , Femenino , Genotipo , Hepatitis B/complicaciones , Antígenos de Superficie de la Hepatitis B/química , Virus de la Hepatitis B/clasificación , Virus de la Hepatitis B/aislamiento & purificación , Humanos , Neoplasias Hepáticas/complicaciones , Masculino , Persona de Mediana Edad , Mutación , Estudios Prospectivos , Precursores de Proteínas/química , Eliminación de Secuencia , Adulto JovenRESUMEN
La hipertensión pulmonar asociada es un padecimiento poco frecuente en los pacientes con lupus (LES), que por su morbimortalidad conlleva un pronóstico grave en el embarazo y posparto inmediato. El aumento de la resistencia arterial pulmonar asociado a los cambios fisiológicos cardiovasculares del fin del embarazo y del trabajo de parto generan una situación clínica de dificultoso manejo...Nuestro objetivo es presentar el caso de una paciente con LES previamente diagnosticado, en la que se desarrolla hipertensión pulmonar asociada (HPA)al final del segundo trimestre de un embarazo gemelar, que responde adecuadamente a sildenafil y evoluciona favorablemente (ella y sus dos niños) luego de realizarse cesárea programada en la semana 32.(AU)
Asunto(s)
Adulto , Humanos , Femenino , Hipertensión Pulmonar/diagnóstico , Hipertensión Pulmonar/patología , Lupus Eritematoso Sistémico/diagnóstico , Complicaciones del Embarazo/patologíaRESUMEN
La hipertensión pulmonar asociada es un padecimiento poco frecuente en los pacientes con lupus (LES), que por su morbimortalidad conlleva un pronóstico grave en el embarazo y posparto inmediato. El aumento de la resistencia arterial pulmonar asociado a los cambios fisiológicos cardiovasculares del fin del embarazo y del trabajo de parto generan una situación clínica de dificultoso manejo...Nuestro objetivo es presentar el caso de una paciente con LES previamente diagnosticado, en la que se desarrolla hipertensión pulmonar asociada (HPA)al final del segundo trimestre de un embarazo gemelar, que responde adecuadamente a sildenafil y evoluciona favorablemente (ella y sus dos niños) luego de realizarse cesárea programada en la semana 32.
Asunto(s)
Adulto , Humanos , Femenino , Hipertensión Pulmonar/diagnóstico , Hipertensión Pulmonar/patología , Lupus Eritematoso Sistémico/diagnóstico , Complicaciones del EmbarazoRESUMEN
Epidemiological surveillance for hydatidosis is based on initial determination and follow-up of the infestation rate in man, sheep and dogs. The use of ultrasonography (US) as a screening method has demonstrated its usefulness in detecting asymptomatic human carriers of abdominal hydatidosis. To evaluate the contribution of US to epidemiological surveillance within the framework of disease control programs, we performed 719 US studies in school children from 7 to 13 years of age, in rural areas of Río Negro, Argentina, subjected to canine deparasitization during 1984/1986 and 1997/1998. In the first period, 15/268 (5.6%), while in the second, 5/451 (1.1%) carriers were detected (P < 0.0004). The average diameter of the cysts was 4.71 cm in 1984/1986 and 2.14 in 1997/1998. US as a mass screening method allows evaluation of early changes in human prevalence rates, closely related to infestation rates in sheeps and dogs, thus providing a sensitive indicator of the evaluation of control programs.
Asunto(s)
Abdomen , Equinococosis/diagnóstico por imagen , Vigilancia de la Población , Abdomen/parasitología , Adolescente , Animales , Argentina/epidemiología , Niño , Equinococosis/epidemiología , Equinococosis/prevención & control , Echinococcus/aislamiento & purificación , Humanos , Control de Infecciones , Prevalencia , Población Rural , UltrasonografíaRESUMEN
Our aim was to investigate if interferon plus ribavirin has any effect on serum HCV quasispecies distribution and the relationship between diversity of HCV quasispecies and treatment response. In all, 21 patients were treated with interferon plus ribavirin for 48 weeks. The presence of HCV quasispecies was determined in serum samples at baseline and at the fourth week of treatment by SSCP analysis of the hypervariable region. SSCP pattern was defined as single or multiple band. A single band was found in six patients and multiple bands in nine. No significant difference was found between SSCP pattern in pretreatment samples and response to the therapy. In none of the patients were observed changes in number of SSCP bands between samples taken at baseline and in the fourth week of the therapy. In conclusion, the complexity of HCV quasispecies before the therapy was not related to treatment response; combined therapy did not affect serum HCV quasispecies.
Asunto(s)
Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/virología , Interferón-alfa/administración & dosificación , Ribavirina/administración & dosificación , Adulto , Quimioterapia Combinada , Femenino , Genotipo , Hepacivirus/genética , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo Conformacional Retorcido-Simple , ARN Viral/sangre , Resultado del TratamientoRESUMEN
A case of cholestasis due to a synchronous pancreatic head metastasis from an occult lobular breast carcinoma is presented. The patient had a clinical and radiological picture compatible with a pancreatic head primary tumor with cholestasis and ascites. Ultrasonographically guided fine needle aspiration cytology demonstrated a metastatic breast lobular cancer (positive for cytokeratin AE1 and AE3, cytokeratin 7 and epithelial membrane antigen and negative for cytokeratin 20, CA 19.9, CA 125, CEA and estrogenic receptors). The same cytologic findings were observed in skin and subcutaneous armpit nodules. Clinical and radiological breast examination was unable to demonstrate any tumor in the breast. Pancreatic metastases are rare events and the majority of them are secondary to renal and lung cancer and rarely to breast cancer. In these latter cases, metastases are usually disclosed after a disease-free interval of months or years between primary tumor resection and recognition of the pancreatic tumor. Synchronous presentation is extremely rare. Metastases of epithelial origin are uncommon in pancreas and generally are first misdiagnosed as primary pancreatic cancer. Fine needle aspiration is a useful tool for the differential diagnosis in patients with widespread disease.
Asunto(s)
Neoplasias de la Mama/patología , Carcinoma Lobular/secundario , Neoplasias Primarias Desconocidas/patología , Neoplasias Pancreáticas/secundario , Biopsia con Aguja , Femenino , Humanos , Persona de Mediana EdadRESUMEN
In areas where human cystic echinococcosis (CE) is endemic, the results of ultrasonographic or X-ray examinations have revealed a surprisingly high prevalence of abdominal cysts in asymptomatic individuals. The results of preliminary studies indicate that the ratio of liver infection:lung infection (LI:LU) is much higher in the asymptomatic individuals (9:1 or 7:1) than is usual among symptomatic cases of liver CE (2:1). This difference may indicate that, compared with lung cysts, liver cysts rarely cause morbidity, perhaps because they grow at a slower rate than those in the lungs. In an attempt to explore this possibility, the published results of ultrasonographic and radiological surveys on general populations and the records of autopsies and hospital-based investigations of symptomatic cases of liver CE were reviewed. In general populations, the overall prevalence of cysts in the liver (2.5%) was found to be much higher than that of cysts in the lungs (0.3%), giving a LI:LU ratio of 8.3:1. In the symptomatic cases, however, LI:LU ratios were only 2.5:1 (based on hospital records) or 4.1:1 (based on autopsy records). In addition, the estimated mean growth rate of the cysts in 53 surgical cases of CE from the province of Río Negro in Argentina was found to be significantly higher than that of the cysts in 89 asymptomatic cases detected during ultrasonographic surveys in the same area.
Asunto(s)
Equinococosis Hepática/patología , Equinococosis Pulmonar/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Portador Sano , Niño , Equinococosis Hepática/epidemiología , Equinococosis Pulmonar/epidemiología , Humanos , Modelos Lineales , Persona de Mediana Edad , Prevalencia , PronósticoRESUMEN
BACKGROUND: Sarcoidosis is a multisystemic granulomatous disorder of unknown etiology that most commonly affects young adults. A probable induction of sarcoidosis by interferons (IFN) has been published. To this date, few cases of cutaneous sarcoidosis inpatients with chronic hepatitis C under interferon treatment have been reported. OBJECTIVE: We describe a 50-year-old woman with chronic hepatitis C who developed lesions of cutaneous sarcoidosis three months after IFN treatment. CONCLUSIONS: The possible role of INF therapy in the development of cutaneous sarcoidosis in a patient with chronic hepatitis C should be considered.
Asunto(s)
Antivirales/efectos adversos , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/efectos adversos , Sarcoidosis/inducido químicamente , Enfermedades de la Piel/inducido químicamente , Antivirales/uso terapéutico , Femenino , Hepatitis C Crónica/complicaciones , Humanos , Interferón-alfa/uso terapéutico , Persona de Mediana Edad , Sarcoidosis/complicaciones , Enfermedades de la Piel/complicacionesRESUMEN
Se presenta un caso de tumor de cabeza de páncreas con colestasis debido a una metástasis de un carcinoma lobular oculto de mama. El cuadro es interpretado inicialmente como un carcinoma de páncreas diseminado, con ascitis, colestasis e implantes peritoneales. La biopsia de lesiones de piel y celular subcutánea que resultan en metástasis de carcinoma lobular de mama, confirmado con inmunomarcación (positiva para citoqueratinas clon AE1 y AE3, citoqueratina 7 y antígeno epitelial de membrana y negativa para citoqueratina 20, CA 19.9, CA 125, CEA y receptores estrogénicos) hacen a la presunción de metástasis pancreática. Esta presunción se confirma mediante PAAF ecoguiada. Las metástasis en páncreas de tumores primitivos de origen epitelial son infrecuentes y en general se presentan como imágenes nodulares indistinguibles de los tumores primitivos. Se observan habitualmente en casos de diseminación masiva por carcinoma de riñon o de pulmón siendo raras las metástasis de carcinoma de mama, las cuales se presentan habitualmente con el antecedente de cáncer de la misma. El diagnóstico del tumor pancreático debe ser efectuado por anatomía patológica. Este es un caso atípico en su forma de presentación, dada la aparición de colestasis debida a un tumor metastático a nivel de cabeza de páncreas sincrónico con un carcinoma lobular de mama oculto. (Au)
Asunto(s)
Humanos , Femenino , Persona de Mediana Edad , Neoplasias Pancreáticas/secundario , Neoplasias de la Mama/patología , Carcinoma Lobular/patología , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/patología , Neoplasias de la Mama/diagnóstico , Carcinoma Lobular/diagnóstico , Neoplasias Primarias Desconocidas/patología , Neoplasias Primarias Desconocidas/diagnóstico , Biopsia con AgujaRESUMEN
A case of cholestasis due to a synchronous pancreatic head metastasis from an occult lobular breast carcinoma is presented. The patient had a clinical and radiological picture compatible with a pancreatic head primary tumor with cholestasis and ascites. Ultrasonographically guided fine needle aspiration cytology demonstrated a metastatic breast lobular cancer (positive for cytokeratin AE1 and AE3, cytokeratin 7 and epithelial membrane antigen and negative for cytokeratin 20, CA 19.9, CA 125, CEA and estrogenic receptors). The same cytologic findings were observed in skin and subcutaneous armpit nodules. Clinical and radiological breast examination was unable to demonstrate any tumor in the breast. Pancreatic metastases are rare events and the majority of them are secondary to renal and lung cancer and rarely to breast cancer. In these latter cases, metastases are usually disclosed after a disease-free interval of months or years between primary tumor resection and recognition of the pancreatic tumor. Synchronous presentation is extremely rare. Metastases of epithelial origin are uncommon in pancreas and generally are first misdiagnosed as primary pancreatic cancer. Fine needle aspiration is a useful tool for the differential diagnosis in patients with widespread disease.
RESUMEN
Se presenta un caso de tumor de cabeza de páncreas con colestasis debido a una metástasis de un carcinoma lobular oculto de mama. El cuadro es interpretado inicialmente como un carcinoma de páncreas diseminado, con ascitis, colestasis e implantes peritoneales. La biopsia de lesiones de piel y celular subcutánea que resultan en metástasis de carcinoma lobular de mama, confirmado con inmunomarcación (positiva para citoqueratinas clon AE1 y AE3, citoqueratina 7 y antígeno epitelial de membrana y negativa para citoqueratina 20, CA 19.9, CA 125, CEA y receptores estrogénicos) hacen a la presunción de metástasis pancreática. Ésta presunción se confirma mediante PAAF ecoguiada. Las metástasis en páncreas de tumores primitivos de origen epitelial son infrecuentes y en general se presentan como imágenes nodulares indistinguibles de los tumores primitivos. Se observan habitualmente en casos de diseminación masiva por carcinoma de riñon o de pulmón siendo raras las metástasis de carcinoma de mama, las cuales se presentan habitualmente con el antecedente de cáncer de la misma. El diagnóstico del tumor pancreático debe ser efectuado por anatomía patológica. Este es un caso atípico en su forma de presentación, dada la aparición de colestasis debida a un tumor metastático a nivel de cabeza de páncreas sincrónico con un carcinoma lobular de mama oculto.
Asunto(s)
Humanos , Femenino , Persona de Mediana Edad , Neoplasias de la Mama , Carcinoma Lobular , Neoplasias Pancreáticas , Biopsia con Aguja , Neoplasias de la Mama , Carcinoma Lobular , Neoplasias Primarias Desconocidas , Neoplasias PancreáticasRESUMEN
Hepatitis E virus (HEV) has been identified in 2 Argentine patients with acute hepatitis who reported no history of travel to regions in which HEV is considered endemic. These isolates are the first to be identified in South America. By use of degenerate primers from open reading frames 1 and 2, HEV sequences were obtained from these patients' serum and compared with published HEV sequences. The Argentine isolates are different from all previously identified HEV isolates and are most closely related to each other. The Argentine isolates are distinct from the most geographically related isolate from Mexico as well as isolates from other endemic (China, Southeast Asia, and India) and nonendemic (the United States and Europe) regions. Phylogenetic analysis indicate that the Argentine isolates represent a new genotype of HEV, genotype 8, distinct from the Burmese-like genotype 1, Mexican genotype 2, US genotype 3, Chinese/Taiwan genotype 4, and European genotypes 5-7.
Asunto(s)
Virus de la Hepatitis E/aislamiento & purificación , Hepatitis E/virología , Anciano , Anciano de 80 o más Años , Argentina/epidemiología , ADN Viral/análisis , Hepatitis E/epidemiología , Hepatitis E/genética , Virus de la Hepatitis E/clasificación , Virus de la Hepatitis E/genética , Humanos , Masculino , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADNRESUMEN
The aim of this work was to assess if the diversity of hepatitis C virus (HCV) quasispecies is related to histological severity and duration of infection in a cohort of untreated patients with an estimated onset of the disease. A total of 27 patients with diagnosis of chronic liver disease and history of blood transfusion (n = 16) or intravenous drug use (IDU) (n = 11) were included. All were anti-HCV positive and had detectable serum HCV-RNA. The onset and the duration of the disease were estimated from the time of the transfusion or the first drug injection. Patients who consumed drugs for more than 2 years, or were coinfected with HBV or HIV were excluded. History of alcohol intake (> 80 g/day), ALT level and age at infection were recorded. Histological assessment of grading and staging was performed according to Knodell score. The quasispecies diversity was investigated by single strand conformation polymorphism (SSCP) targeted to HVR-E2 region and SSCP pattern was evaluated as a single or multiple bands. The number of quasispecies did not correlate with the estimated duration of the disease. Patients who acquired hepatitis C by blood transfusion did not differ in number of bands from patients who were IDU. There was no correlation between the heterogeneity of HCV quasispecies and age, serum ALT, Knodell score, HAI and fibrosis. In conclusion the quasispecies diversity of E2 had no correlation with grade and stage of chronic HCV infection and the presence of quasispecies was independent of the duration of the disease.
Asunto(s)
Variación Genética , Hepacivirus/genética , Hepatitis C/virología , Adolescente , Adulto , Anciano , Anticuerpos Antivirales/análisis , Enfermedad Crónica , Estudios de Cohortes , Femenino , Humanos , Hígado/virología , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-Simple , ARN/análisis , Especificidad de la EspecieRESUMEN
The usefulness of ultrasonography (US) in the early diagnosis of hydatidosis, applied in large-scale surveys to populations lacking clinical symptoms of the disease, has been amply documented. However, the rate of false positive and negative results is poorly described. Due to this, the present paper is aimed to evaluate the sensitivity, specificity and predictive value of a conventional rural ultrasonographic survey in comparison with higher imaging complexity. Accordingly, during 1997 and 1998 a total of 1054 children from 7 to 14 years of age were evaluated by means of US, in the town of Ingeniero Jacobacci, Province of Rio Negro, Argentina, employing a portable device for population studies. All detected cases were referred to a high complexity center specialized in imaging diagnosis for their re-evaluation with US, CT scanning and X-rays. A control group comprising 3 children negative by US for each positive case in the mass screening survey was selected and reexamined by US and X-rays and CT scanning in doubtful situations. Twenty-seven asymptomatic carriers were referred with images compatible with hydatid cysts, while 66 were classified as disease free. At reexamination, 24 of those diagnosed as carriers and the totality of those classified as healthy were confirmed. On the basis of our results, a sensitivity of 100%, a specificity of 95.6% and a global test value of 96.7% were estimated.
Asunto(s)
Equinococosis/diagnóstico por imagen , Encuestas Epidemiológicas , Salud Rural , Adolescente , Argentina/epidemiología , Estudios de Casos y Controles , Niño , Equinococosis/epidemiología , Humanos , Valor Predictivo de las Pruebas , Salud Rural/estadística & datos numéricos , Sensibilidad y Especificidad , UltrasonografíaRESUMEN
AIM: To study the acute variations in portal and systemic hemodynamics after propranolol and 5-isosorbide mononitrate (IMN) administration in cirrhotic patients. PATIENTS AND METHODS: Seventeen cirrhotic patients with portal hypertension were studied with catheterization and Doppler duplex Ultrasound Systemic hemodynamics. Hepatic venous pressure gradient (HVPG), portal blood flow and resistance were evaluated in baseline, after intravenous propranolol (0.15 mg/kg), and after 20 mg p.o. of IMN. Patients who showed a decrease > or = 20% and/or < 12 mm/hg in HVPG were considered responders. RESULTS: There were no significant differences in clinical or portal hemodynamic baseline data between responders and non-responders to the drugs. After propranolol administration cardiac index decreased (p < 0.05) and pulmonary capillary pressure increased (p < 0.0001). Six patients (35%) were responders; lack of response was associated with an insufficient decrease in portal blood flow or with an increase in portal resistance. After IMN administration cardiac index decreased (p < 0.05) with normalization of pulmonary capillary pressure (p < 0.05). Seven patients were responders to the addition of IMN (5 non-responders to propranolol) and showed a decrease in HVPG associated with a reduction in portal blood flow and resistance; in the remaining 10 patients HVPG did not decrease despite a reduction in portal blood flow, with an increase in portal resistance. CONCLUSIONS: Addition of IMN increased the number of responders and reduced portal blood flow with a variable effect in portal resistance.
Asunto(s)
Antihipertensivos/uso terapéutico , Hipertensión Portal/tratamiento farmacológico , Hipertensión Portal/fisiopatología , Dinitrato de Isosorbide/análogos & derivados , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/fisiopatología , Propranolol/uso terapéutico , Vasodilatadores/uso terapéutico , Femenino , Hemodinámica/efectos de los fármacos , Humanos , Hipertensión Portal/complicaciones , Dinitrato de Isosorbide/uso terapéutico , Cirrosis Hepática/complicaciones , MasculinoRESUMEN
Until a short time ago, hydatidosis was considered a pathology that could only be resolved surgically. However, in recent years progress has been made with the epidemiology, diagnosis, and treatment of the disease, and new information on the natural history of hydatidosis has helped define new criteria for its treatment. It is now known that as many as 67% of the carriers of liver cysts who are asymptomatic remain so throughout their lives. This situation produces special results in immunologic testing. Enzyme-linked immunosorbent assay (ELISA) has a sensitivity of 63% and a specificity of 97% with asymptomatic carriers, while the double diffusion arc 5 test (DD5) achieves a sensitivity of only 31% with the same population. On the other hand, imaging studies based on ultrasonography have become the method of choice to detect asymptomatic carriers. Ultrasonography studies are 49% to 73% more sensitive than serological tests, and they can even be used as a part of epidemiological surveillance systems and to monitor control programs. Treatment schemes have also been modernized. Treating asymptomatic carriers chemotherapeutically with albendazole produces favorable results in as many as 69% of cases, while such minimally invasive surgical treatments as puncture-aspiration-injection-reaspiration (PAIR) reduce average cyst volume by as much as 66%. These factors have made it possible for hospital services in the province of Río Negro, Argentina, to establish a treatment scheme for asymptomatic carriers. It is based on the monitoring of small cysts (type Ia on the modified Gharbi scale); initial treatment with albendazole, followed by PAIR if there is no response, in larger or more complex cysts (types Ib, II, and III); and follow-up of inviable or dead cysts (types IV and V).