Measles vaccination: influence of age on its efficacy

The authors compare the serologic efficacy and the clinical protection afforded by three different measles vaccination schemes in adequately nourished children in São Paulo city, Brazil. Two hundred forty two children were divided into three groups. Group A, comprising 117 children who had received the vaccine before 12 months of age and a second dose at 12 months of age or more. Group B, comprising 46 children who had received only one dose, before 12 months of age. Group C, comprising 79 children who had received only one dose, at 12 months of age or more. The geometric mean titer of antibodies in Group A was 790.1; in Group B, 251.1; and in Group C, 550.3. There was no statistically significant difference between Groups A and C. The exposure to the measles virus was probably similar in all groups, and the children in Groups A and C had similar chances of acquiring the disease after vaccination whereas in Group B the chances were higher when compared to the other two groups. The results obtained in this study favor the use, in developing countries, of a vaccination program against measles that includes an early first dose at eight months of age and revaccination after 12 months of age.

Esporotricosis felina: aspectos clínicos e zoonóticos

La esporotricosis consiste en micosis profunda, de evolución subaguda o crónica decurrente de infección por el hongo dimorfico Sporothrix schenkii. Consiste en dermatopatia mucho frecuente en nuestro medio, resultante de la penetración de abrojos e de arañazos por espinos de plantas. El S. schenkii ha sido descrito, en S. Paulo, en perros, gatos, aseninos, bovinos, equinos y ratones. Todavía, el carácter de antropozoonosis de la enfermedad pocas veces ha sido descrito tanto en la literatura internacional como en la nacional, existiendo apenas una citación en lo Brasil, de probable transmisión gato/hombre. Se discrebió, en lo presente relato, caso clínico de esporotricosis felina con transmisión através de arañadura en propietario, tratador y médico veterinário. Un gato, sin raza definida, macho, con 3 años, mucho agresivo, con grave cuadro cutáneo (cefálico, torácico y de miembros torácicos) manifestado por lesiones ulceradas, exudativas de alopecia, deposición de crostas hemorrágicas, agraviado por síntomas de lo complejo respiratorio felino, donde por su temperamento agresivo habia arenado en corto espacio de tiempo 5 individuos, donde 3 de los individuos manifestaron sintomas de evolución y gravedad distintas. El diagnostico clínico presuntivo fue confirmado perlo examen histopatológico (H.E., PAS) de fragmentos de piel, linfonodos y amígdalas cogidos, "intra-vitam" y/o "post-morten", per lo aislamiento de lo agente, per la inoculación en testículos de ratas adultas y posterior nuevo aislamiento. Se confirmó la patologia por pruebas suerológicas (F.C., anticuerpos precipitantes) y prueba de intradermoreación (esporotriquina) en los pacientes acometidos.

Loxoscelismo en Chile: estudios epidemiológicos, clínicos y experimentales

Se presenta un enfoque panorámico de estudios epidemiológicos, clínicos y experimentales referentes a Loxosceles laeta y loxoscelismo efectuados en 1955-1988 en Santiago, Chile. Se estudiaron 216 casos de loxoscelismo. Los hechos más relevantes fueron: 52,8% correspondió a mujeres; edad entre 7 meses y 78 años; 84,3% fué loxoscelismo cutáneo (LO y 15,7% loxoscelismo cutáneo-visceral (LCV); 73,6% sucedió en época calurosa; en 86,6% el accidente ocurrió en la vivienda, especialmente en dormitorios, mientras la persona dormía o se vestía. La araña fué vista en 60,2% de los casos e identificada en laboratorio como L. laeta en 17,7% (10,6% de los 216 casos). Los sitios más frecuen temente afectados fueron las extremidades con 67,6%, lancetazo urente fué el síntoma inicial más frecuente. Dolor, edema y placa livedoide, la cual posteriormente se transformaría en escara necrótica, fueron las manifestaciones locales predominantes. En LCV hematuria y hemoglobinuria fueron constantes, ictericia, fiebre y compromiso de conciencia se presentaron en la mayoría de los casos. Tratamiento: LC con antihistamínicos o corticoides inyectables, LCV con corti-coides inyectables. La condición de los pacientes en el último control fué: curación completa en 75,5%, curación con secuela cicatrizal en 8,3%, muerte en 3,7% (todos con LCV) y abandono en 12,5%. Adicionalmente, se ha efectuado una serie de estudios experimentales, tanto in vivo como in vitro para esclarecer aspectos básicos sobre el veneno de L. laeta y el tratamiento del loxoscelismo.

A multivariate analysis of socio-demographic factors, water contact patterns and Schistosoma mansoni infection in an endemic area in Brazil

Associations between socio-demographic factors, water contact patterns and Schistosoma mansoni infection were investigated in 506 individuals (87% of inhabitants over 1 year of age) in an endemic area in Brazil (Divino), aiming at determining priorities for public health measures to prevent the infection. Those who eliminated S. mansoni eggs (n = 198) were compared to those without eggs in the stools (n = 308). The following explanatory variables were considered: age, sex, color, previous treatment with schistosomicide, place of birth, quality of the houses, water supply for the household, distance from houses to stream, and frequency and reasons for water contact. Factors found to be independently associated with the infection were age (10-19 and > 20 yrs old), and water contact for agricultural activities, fishing, and swimming or bathing (Adjusted relative odds = 5.0, 2.4, 3.2, 2.1 and 2.0, respectively). This suggests the need for public health measures to prevent the infection, emphasizing water contact for leisure and agricultural activities in this endemic area.

Blood groups and malaria

The possible relationship between erythrocyte antigens and the presence of malaria infection by P. vivax and P. falciparurn was sought in four different ethnic groups of two departments of Colombia. Malaria infection by P. falciparum was found in 91.4% of malaria infected blacks. No significant differences were found between the presence of malaria infection and ABO antigens. In the other blood groups, it was observed that groups MNSs conferred black people a greater Rr for malaria by both species of Plasmodium and that Duffy-negative blacks and indians appeared to be resistant to P. vivax infection. A predominance of P. vivax infection was observed in Katio indians while P.falciparum was predominant in Kuna indians; the reason for this finding still needs to be explored.

Leishmania (Viannia) panamensis - induced cutaneous leishmaniasis in susceptible and resistant mouse strains

We studied the susceptibility to Leishmania (Viannia) panamensis in strains of mice. The C57BL/6 strain was resistant and showed self-controlled lesion at the injected foot pad. The BALB/c and DBA/2J strains were susceptible and showed a foot swelling that started day 20 post-infection and progressed to a tumour-like lesion in later period of observation. The CBA/HJ strain was found to be of intermediary resistance. In contrast to other known cutaneous leishmaniasis in mice, the lesion in L. (V.) panamensis-infected mice was restricted to the inoculation site in the skin. In addition, we studied the development of cellular response and antibodies against Leishmania antigen in BALB/c and C57BL/6 strains. The proliferative response of lymph node cells against L. (V.) panamensis antigen was biphasic in both strains. An initial response was seen on day 20, followed by a refractory period between 40 and 80 days and a second response around fourth month post-infection. The response in the latter period was higher in C57BL/6 strain than in BALB/c strain. BALB/c strain presented much higher anti-Leishmania antibody level than C57BL/6 strain. The model and the correlation of immunological variables and the course of the infection are discussed.

Seroepidemiology of human toxoplasmosis in Chile

A series of already published and unpublished seroepidemiological surveys for toxoplasmosis, carried out in Chile in 1982-1994, is reviewed, expanded and analyzed. The surveys included 76,317 apparently healthy individuals of different ages (0.57% of the country's total population), from 309 urban and rural-periurban localities. Urban groups were integrated by blood donors, delivering mothers and middle grade schoolchildren, while rural-periurban individuals corresponded to unselected family groups. Blood samples were collected in filter paper. The presence of antibodies to Toxoplasma gondii was determined by the indirect hemagglutination test (IHAT), titers > 16 were considered positive. The test resulted positive in 28,124 (36.9%) of the surveyed people. Two hundred and six (0.3%) individuals presented IHAT titers > 1000, probably corresponding to acute or reactivated infections. A progressive increase of positive IHAT from northern to southern regions of the country was noted, phenomenom probably related to geographical conditions and to a higher production and consumption of different types of meat in the latter regions. It is postulated that ingestion of T. gondii cysts by humans is epidemiologically as important as ingestion of oocysts. The results presented stress the epidemiological importance of toxoplasmosis in humans, and warn about eventual implications in immunocompromised patients and in transplacental transmission, organ transplants and transfusions.

Decay of antibody isotypes against early developmental stages of Schistosoma mansoni after treatment of schistosomiasis patients

Antibodies to a number of parasite antigens are found in schistosomiasis patients, and antibodies to early developmental stages were demonstrated to be efficient immunologic markers for the diagnosis of schistosomiasis. In the present study, decay patterns of IgM and IgG antibodies against cercariae and schistosomula were investigated, in comparison to antibodies against worms and eggs in schistosomiasis patients after chemotherapy, for an investigation of seroepidemiologic aspects. Data obtained in the study of 359 serum samples from patients with Schistosoma mansoni infection, noninfected individuals, and patients followed-up for a period of 12 to 15 months after treatment provided the basis to postulate a general pattern for the kinetics of antibody decay. Before treatment, the antibody pattern was represented by a unimodal curve, which shifted to a bimodal curve after treatment, and ended with a unimodal curve similar to that for the noninfected group. Different types of antibodies were classified into four categories according to their decay features, and anti-schistosomulum IgM was classified into the moderate-decay caterogy, whereas other antibodies to early parasite stages were classified into the slow-decay category. The present methodology permits the identification of the most suitable antibodies to be detected in field control programs for schistosomiasis or other parasitoses

Congenital Chagas disease of second generation in Santiago, Chile. Report of two cases

Congenital Chagas disease (CChD) has been reported in different countries, mostly in Latin America. In 1987 a fatal case of CChD of second generation (CChDSG) was published. Within a period of six months - 1989-1990 - two cases of CChDSG were diagnosed and studied in the city of Santiago. Two premature newborns, sons of two sisters, with moderate liver and spleen enlargement, were found to have positive serology for Chagas disease and xenodiagnoses. The mothers, urban residents all their lives, without antecedents of triatomine bugs contact or blood transfusions, showed positive serology and xenodiagnoses. Their mother (grandmother of the infants), lived 20 years in a Northern rural Chagas disease endemic locality, in a triatomine infested house. Afterwards, she moved to Santiago, where she married and has resided up to now. Serology and xenodiagnoses were also positive. All the Trypanosoma cruzi infected individuals were successfully treated with nifurtimox.

Human toxocariasis: a seroepidemiological survey in the municipality of Campinas (SP), Brazil

The occurrence of human Toxocara infection was evaluated in three neighborhoods of the periphery of the Campinas municipality (Jardim Santa Mônica, Jardim São Marcos and Jardim Campineiro) in 1999. Forty residences and 138 residents were randomly selected by drawing lots and were submitted to a seroepidemiological survey, which included blood collection for the immunoenzymatic detection (ELISA) of anti-Toxocara antibodies and a blood count, and the application of a semi-structured questionnaire for the evaluation of epidemiological data. Significant levels of anti-Toxocara antibodies were detected in 23.9% of the 1999 samples. No significant difference in the frequency of infection according to age was observed. Environmental contamination with Toxocara eggs was observed in 12.3 and 14.0% of 57 soil samples collected in the same region in December 1998 and July 1999, respectively. Univariate analysis and multiple logistic regression of the data obtained from the questionnaires and of the results of the serological tests, suggest a significant influence of socioeconomic variables on the frequency of human infection with Toxocara under the conditions prevalent in the study area.

Human toxocariasis: incidence among residents in the outskirts of Campinas, State of São Paulo, Brazil

With the aim of estimating the incidence of infection by Toxocara among residents in the outskirts of Campinas (State of São Paulo, Brazil) two serological surveys, using ELISA anti-Toxocara tests, were performed in January 1999 and January 2000, involving, respectively, 138 and 115 individuals, 75 of which examined in both occasions. Among this group 67 individuals did not show the presence of anti-Toxocara antibodies in 1999, and 12 presented seroconversion in the second survey, revealing an annual incidence rate of 17.9%.

First report of a human case of polycystic echinococcosis due to Echinococcus vogeli from neotropical area of Peru, South America

We report a human case of polycystic hidatidosis due to Echinococcus vogeli from Contamana (Department of Loreto) village located in the central jungle of Peru. The patient is a 44 year-old lady, teacher, who carried a painless liver mass since a year ago. She was submitted to abdominal surgery and the liver mass was removed and showed multiple cysts containing colorless liquid as is showed in the polycystic hidatidosis. The morphology and measure of the hooks obtained from the liquid contained in the cysts are from Echinococcus vogeli. It is the first report of this parasitism in Perú.

Clinical laboratory assessment of hepatitis C and HIV coinfected patients according to the antiretroviral therapy received

During the year of 2001, a retrospective, descriptive study in order to determine the influence of the antiretroviral therapy received by 111 HIV-HCV coinfected patients who had undergone at least one liver biopsy was conduced, 74 of them were treated with a protease inhibitor regimen (WPI), and 37 with a non-protease inhibitor regimen (NPI). The main characteristics found were: a young patient population (mean age 41 years old in both groups), composed in most part of male individuals (74.3% WPI and 51.4% NPI) with previous risk factors for both infections (WPI 93.2% and NPI 89.2%). The most significant findings included AIDS-defining disease (WPI 18.9% and NPI 13.5% of the cases), elevated hepatic enzyme levels (WPI: SGOT 52.1 and NPI 53.2), absence of liver disease-related symptoms (16.2% for both groups), average CD4 count > 350 for both groups (WPI 362.2 and NPI 378.1), predominantly low-grade fibrosis in both populations (0-2 in 63.6% of WPI patients and in 80% of NPI patients), with necro-inflammatory activity ranging from 5-7 in 51.3% and 42.9% of WPI patients and NPI patients, respectively. It is suggested a sequential biopsy to better evaluate the evolution of the hepatic disease, according to the HAART regimen received.

Characterization of a clone from an adult worm cDNA library selected with anti-Schistosoma mansoni human antibodies dissociated from immune complexes: a preliminary report

Considering the scarcity of defined antigens, actually useful and reliable for use in the field studies, we propose an alternative method for selection of cDNA clones with potential use in the diagnosis of schistosomiasis. Human antibodies specific to a protein fraction of 31/32 kDa (Sm31/32), dissociated from immune complexes, are used for screening of clones from an adult worm cDNA library. Partial sequencing of five clones, selected through this strategy, showed to be related to Schistosoma mansoni: two were identified as homologous to heat shock protein 70, one to glutathione S-transferase, one to homeodomain protein, and one to a previously described EST (expressed sequence tag) of S. mansoni. This last clone was the most consistently reactive during the screening process with the anti-Sm31/32 antibodies dissociated from the immune complexes. The complete sequence of this clone was obtained and the translation data yielded only one ORF (open reading frame) that code for a protein with 57 amino acids. Based on this amino acid sequence two peptides were chemically synthesized and evaluated separately against a pool of serum samples from schistosomiasis patients and non-schistosomiasis individuals. Both peptides showed strong reactivity only against the positive pool, suggesting that these peptides may be useful as antigens for the diagnosis of schistosomiasis mansoni.

Clinical and histological characteristics of HIV and hepatitis C virus-co-infected patients in Brazil: a case series study

Hepatitis C virus (HCV) is an important factor contributing to morbidity and mortality in patients co-infected with HIV and HCV. In addition, liver biopsy is an important tool in the clinical management of these patients. Although liver biopsy is controversial, it is recommended for all patients. Data regarding the clinical and histological characteristics of these patients are scarce not only in Brazil but in Latin America as a whole. With the goal of better understanding these characteristics and the benefit of liver biopsy indications in this disease setting, data collected from 234 patients followed from 1996 to 2004 at Casa da AIDS, São Paulo, were analyzed. The following variables were extracted from the patients' medical files at the time of liver biopsy: sex, age, hepatitis C infection risk factors, hepatitis C infection duration, ALT levels, CD4+ T cell counts, history of alcohol abuse, history of antiretroviral therapy, HCV genotype, and liver histological alterations. CONCLUSIONS: 1 - Hepatitis C virus 1 and 3 were the most frequently identified genotypes and were diagnosed in 72% and 25.5% of cases respectively; 2 - Structural liver alterations were found to be mild or absent in 48.2% (113/234) of the analyzed patients; 3 - Fifty-three patients (23%) had normal ALT levels and 4 - Significant liver architectural changes (F2-F3) were evident in 22.5% of the patients with normal ALT levels.