Ivermectin treatment of bancroftian filariasis in Recife, Brazil.

To determine the effectiveness of single oral dosages of ivermectin ranging between 20 and 200 micrograms/kg and to make detailed observations of both the kinetics of parasite killing and the adverse reactions induced by treatment, the present double-blind study on ivermectin treatment of lymphatic filariasis caused by Wuchereria bancrofti was undertaken with 43 microfilaremic patients in Recife, Brazil. Follow-up at one year indicated equivalent efficacy for the 20-, 100-, and 200-micrograms/kg drug dosages in reducing microfilaremia to geometric means of 13-25% of pretreatment levels. Adverse clinical reactions (predominantly fever, headache, weakness, and myalgia) occurred to some degree in almost all patients but generally lasted only 24-48 hr and were easily managed symptomatically. Adverse reactions were significantly milder in those receiving the lowest (20 micrograms/kg) ivermectin dose, and they were significantly correlated with individuals' pretreatment microfilaremia levels in all groups. Posttreatment eosinophilia was a regular feature of the response to treatment, with the magnitude and kinetics also proportional to pretreatment microfilarial levels. Transient pulmonary function abnormalities (16 of 42, 38%), liver enzyme elevations (10 of 43, 23%), and hematuria (9 of 42, 22%) developed posttreatment, but all cleared without significant complications. The results indicate that W. bancrofti from Brazil is similar to strains of the parasites studied elsewhere in susceptibility to ivermectin, that the drug's systemic adverse reactions are essentially those resulting from parasite clearance, and that the intensity of these reactions can be significantly reduced by using the low (20 micrograms/kg) dose of ivermectin. This detailed dose-finding study provides information necessary for developing optimal regimens to treat bancroftian filariasis with ivermectin either alone or in combination with other medications.

"In vivo" leukocyte chemotaxis in experimental mice Schistosoma mansoni infection.

The "in vivo" chemotaxis was studied in C57Bl/10 mice 10, 30, 50 and 60 days after a Schistosoma mansoni infection in comparison to a control group (uninfected mice). Staphylococcal protein A was injected into a connective tissue air pouch of control and experimental mice and the leukocyte chemotaxis was counted. A decrease in polymorphonuclear (PMN) leukocyte response was found in infected mice in comparison to the control group (p < 0.05). The 10 day infected mice showed a decreased PMN leukocyte response respecting the control group (p < 0.05) and this finding became more evident 30 and 50 days post-infection. Although the PMN leukocyte response of 60 day infected mice increased in comparison to 50 day infected animals, it was still significantly lower the control response. The mononuclear leukocyte response was not significantly different between infected or uninfected mice.

Reduction of morbidity in hepatosplenic schistosomiasis mansoni after treatment with praziquantel: a long term study.

Forty-two with hepatosplenic patients treated with praziquantel and followed up for 5 years. One half of the patients received a single 30 mg/kg dose and the other half, two doses of 25 mg/kg given 4 hrs apart. According to Hoffman and Kato-Katz stool exams, an 83.3% cure rate, was observed after twelve months. Stool egg counts in cases of incomplete cure were greatly reduced. Liver function, as assessed by serum levels of aspartate aminotransferase, alanine aminotransferase, gamma glutamyltransferase and alkaline phosphatase activities as well as albumin and gamma globulin showed marked improvement after one year. Hepatomegaly was reduced in 81.0% of patients and splenomegaly in 78.8%. Spleen regression was complete in 15.1% of the total, and in 18.5% of those with compensated hepatosplenic disease. As a result of these observations, the authors recommend early treatment with anti-schistosomal medication, either oxamniquine or praziquantel, to halt progression of disease and reduce splenomegaly.

[Tropical filarial pulmonary eosinophilia and its differential diagnosis]. / Eosinofilia pulmonar tropical filariótica e o seu diagnóstico diferencial.

The authors present a comprehensive review of Tropical Pulmonary Eosinophilia (TPE) of filarial etiology and describe its differential diagnosis with similar syndromes. Epidemiological, clinical, diagnostic, therapeutic and phisiopathological aspects are considered, with an emphasis on new advances in our knowledge of lymphatic filariasis and their implication for improved understanding of TPE and similar syndromes. A TPE-like syndrome, which is caused by intestinal helminth infections, occurs in filariasis-endemic and non-endemic areas alike. The authors suggest guidelines for interpreting epidemiological, clinical, laboratory, radiologic (including ultrasonographic) and therapeutical data and properly diagnosing TPE syndromes. This guidelines also should be useful for physicians in areas where filariasis is not endemic but to which patients from endemic area (e.g., Greater Recife-PE, Maceió-AL and Belém-PA) frequent migrate.

Factors involved in Schistosoma mansoni infection in rural areas of northeast Brazil.

Two contiguous villages in Tracunhaém county (State of Pernambuco), endemic for schistosomiasis, were studied: Itapinassu (138 inhabitants) and São Joaquim (91 inhabitants). Agriculture predominates in the former region while ceramics is the main activity in the latter. Although no statistical difference was found regarding prevalence, severe infection (> 400 epg) predominated in Itapinassu, probably related to the kind of occupation. No association was found between parasite burden and severity of disease, in spite of the high infection rates for Schistosoma mansoni in both communities (approx. 60%). Typical epidemiological features of schistosomiasis such as age-related prevalences and intensities of infection (high in children, low in adults) were also mutual characteristics. Nutritional status determined through anthropometric evaluation was carried out by measuring specific anthropometric indicators. A deficit of energy intake, as well as vitamin A and riboflavin deficiencies were detected. The prevalence of moderate or severe undernutrition in patients under 18 years old was 21.9% in Itapinassu and 24.1% in São Joaquim. In this group an association was found between prevalence of schistosomiasis and chronic undernutrition. Similarly, for patients over 18 year old the prevalence of undernutrition was higher than 20%. However, in this case no association between nutritional status and either prevalence of schistosomiasis or parasite burden could be detected. The two communities had not been treated for eight years.

PIP: Patterns of schistosomiasis infection were compared in two contiguous endemic villages in Northeast Brazil's Tracunhaem County (Pernambuco State): Itapinassu (138 inhabitants) and Sao Joaquim (91 inhabitants). The overall prevalence of schistosomiasis in Tracunhaem State was 58.7%; this rate was 61.6% in Itapinassu and 54.2% in Sao Joaquim. Severe infection (400 epg) was more prevalent in Itapinassu (35.1%) than Sao Joaquim (13.3%) and ultrasound revealed more severe pathologic changes (e.g., periportal fibrosis, right liver lobe shrinkage, left lobe and spleen enlargement) in the former village. The higher prevalence of severe infection in Itapinassu is likely related to the predominance of agricultural occupations; in Sao Joaquim, most residents are engaged in ceramics. Schistosomiasis prevalence was significantly positively associated with increasing age, male sex, residence in the village for more than 5 years, daily water contact, fishing, laundering, less than a 10 m distance from an infected stream, lack of cesspools, and chronic undernutrition. A deficit of energy intake, as well as vitamin A and riboflavin deficiencies, was detected in both villages. The role of each of these factors (especially nutritional status) will be analyzed further in order to develop an integrated model for local control of the disease.

Estudo da imunidade humoral e celular na doenca hepatica esquistossomotica. / Humoral and cellular immunity in hepatic schistosomatic disease

Foram estudados 40 pacientes de esquistossomose mansonica,em sua forma hepato-esplenica, divididos em 02 grupos: Grupo I, fase compensada _ 20 casos e Grupo II, fase descompensada _ 20 casos. Vinte e dois individuos pertenciam ao sexo masculino e 18 ao feminino.A idade variou de 11 a 66 anos, predominando os grupos estarios de 11 a 30 anos. Os testes utilizados para pesquisa de imunidade humoral foram os seguintes: dosagem de gamablobulina, dosagem das imunoglobulinas G, M e A e contagem de linfocitos T, reacoes intradermicas com antigenos conhecidos (PPD, candidina,tricofitina e varidase) e investigacao de sensibilizacao ao dinitroclorobenzeno (DNCB). Como conclusao geral, verificou-se que esquistossomaticos hepato-esplenicos apresentaram, em sua maioria, hipersensibilidade de tipo humoral, e, ao mesmo tempo, nitida tendencia para depressoes de imunidade celular, essa ultima evidente, sobretudo, nos pacientes em fase de descompensacao hepatica. Varias possibilidades foram discutidas para explicacao da patogenia desta imunodepressao