Between August 1988 and July 1990, 176 patients with Schistosoma mansoni infection attending the University Hospital, Recife, Brazil received a complete clinical examination including stool examination for intestinal parasites, liver function tests, and ultrasonography. The majority were also examined by upper digestive tract endoscopy. The clinical distribution of their disease was as follows: 26.7% intestinal, 13.6% hepato-intestinal, 53.4% compensated hepatosplenic and 6.3% decompensated hepatosplenic. Infection intensity was high, with a median of 360 eggs/g of faeces. Ultrasonography showed a good correlation between the degree of hepatic periportal fibrosis and the clinical stage of disease (P < 0.0001). Of the patients with the intestinal form of schistosomiasis, 12.8% had grade I fibrosis and the others had no fibrosis; 33.3% of patients with hepatointestinal schistosomiasis had grade I fibrosis, 8.3% had grade II fibrosis, and 58.4% had no fibrosis; all the patients with hepatosplenic disease had grade II or grade III fibrosis. The degree of liver fibrosis detected by ultrasonography correlated with the degree of oesophageal varices detected by endoscopy (P = 0.0001). The degree of oesophageal varices also correlated with the presence of haemorrhage (P < 0.0001). Ultrasonography is considered superior to liver biopsy, permitting a dynamic approach to the study of schistosomiasis morbidity with precise diagnosis and simple sequential follow-up of post-treatment results.

Adolescent↗

PubMedDate not supplied

Tolerance of diethylcarbamazine by microfilaraemic and amicrofilaraemic individuals in an endemic area of Bancroftian filariasis, Recife, Brazil.

To determine the tolerance to diethylcarbamazine (DEC) treatment of patients with Bancroftian filariasis, 193 individuals (138 asymptomatic microfilaraemic, 30 amicrofilaraemic diseased patients and 25 asymptomatic amicrofilaraemic endemic residents) were enrolled in a prospective trial with different dose schedules, in a hospital and outpatient clinic setting in Brazil. Systemic adverse reactions, localized adverse reactions, and side effects, related to microfilariae, adult worms and the drug itself, were evaluated. Systemic reactions occurred irrespective of the DEC dose and schedule in about 40% of the microfilariae carriers, but not in amicrofilaraemic diseased patients or residents; they usually consisted of microscopic haematuria, followed by fever and malaise. Localized reactions were manifested by the appearance of inflammatory reactions, mainly in the scrotal area. Nodules containing degenerating adult worms developed mainly in the scrotal lymphatics of microfilaraemic patients, diseased amicrofilaraemic patients, and residents. Drowsiness, which increased with higher doses of DEC, was the most common side effect in both microfilaraemic and amicrofilaraemic individuals, followed by nausea and gastric upset. The results indicate that the occurrence of systemic and local adverse reactions was unrelated to either the dose of DEC or the pretreatment microfilarial density. The severity of systemic reactions was proportional to the microfilarial density. Side effects were dependent on the drug dosage irrespective of infection status.

Adolescent↗

PubMedDate not supplied

Direct assessment of the adulticidal efficacy of a single dose of ivermectin in bancroftian filariasis.

Although the potent microfilaricidal activity of ivermectin is well established, its efficacy against adult Wuchereria bancrofti is unknown. We used longitudinal ultrasound examinations for periods of 3-9 months to assess directly the macrofilaricidal effect of a single 400 micrograms/kg dose of ivermectin in 15 men from Recife, Brazil who were infected with W. bancrofti. Before treatment, microfilarial densities ranged from 3 to 3098 microfilariae per mL of blood, and movements characteristic of the living adult worm (the 'filaria dance sign') were observed by ultrasound examination of the scrotal lymphatic vessels in all 15 men. Following treatment, microfilarial density was markedly reduced in all men, but the filaria dance sign remained unchanged in both location and pattern. Eight months after treatment, a dilated lymphatic vessel was surgically removed from one patient at the site of the filaria dance sign, and 3 intact adult worms were released. When given as a single 400 micrograms/kg dose, ivermectin had no observable effect on adult W. bancrofti. Therefore, prolonged suppression of microfilaraemia following treatment with ivermectin cannot be explained by a macrofilaricidal effect of the drug. Ultrasound is a valuable new tool for directly and rapidly assessing the macrofilaricidal efficacy of antifilarial drugs in lymphatic filariasis.

Adult↗

PubMedDate not supplied

Comparative efficacy of three different diethylcarbamazine regimens in lymphatic filariasis.

To assess the efficacy of diethylcarbamazine (DEC) in clearing Wuchereria bancrofti microfilariae (mf) from the circulation, we conducted a single blind hospital-based therapeutic trial of 3 DEC regimens. All patients were assessed by filtration of 1 mL of venous blood taken before and 1, 3, 6 and 12 months after DEC administration. The efficacy of a 12 d course of 6 mg/kg DEC once daily was identical to that of a similar course with 2 mg/kg given 3 times daily, indicating that split-dose treatment does not improve mf clearance over single daily drug administration. Microfilarial densities in patients treated only once with 6 mg/kg DEC remained significantly higher at 1, 3, and 6 months after treatment. However, all 3 treatment regimens proved equally effective in controlling microfilaraemia after 12 months, when 41, 42 and 40% of patients in the 3 treatment groups were amicrofilaraemic. These results suggest that a single DEC dose of 6 mg/kg administered annually or biannually may be a suitable regimen to control bancroftian filariasis in Recife, Brazil.

Adolescent↗

PubMedDate not supplied

Treatment of bancroftian filariasis in Recife, Brazil: a two-year comparative study of the efficacy of single treatments with ivermectin or diethylcarbamazine.

The effectiveness of single oral doses of ivermectin (200 or 400 micrograms/kg) and diethylcarbamazine (DEC, 6 mg/kg), preceded 4 d earlier by either placebo or very small doses of these drugs, was compared, over a 2-year period, in a double-blind trial in 67 microfilaraemic Brazilian men with bancroftian filariasis. Regimens containing ivermectin alone decreased the number of microfilariae significantly faster and more effectively for the first month after treatment than regimens containing DEC alone, but the latter were significantly more effective throughout the second year after treatment (1.7-8.2% of pretreatment levels with DEC vs. 12.6-30.8% with ivermectin during that period); the higher ivermectin dose showed a tendency towards more effectiveness than the lower dose. Most effective was the combination of ivermectin (20 micrograms/kg) followed 4 d later by DEC (6 mg/kg), with reduction of microfilaraemia to 2.4% of pretreatment levels at 2 years. Adverse reactions were well tolerated with all regimens, the reactions being significantly more generalized (i.e., fever) following ivermectin and localized (i.e., scrotal inflammatory nodules around dying adult worms) following DEC. Further trials of single-dose combination therapy vs. single high doses of ivermectin or DEC should determine the ideal regimen for treatment and control of bancroftian filariasis.

Administration, Oral↗

PubMedDate not supplied

Antigen-specific and -non-specific regulatory influences of antibody in immune responses are determined by variable region properties.

The regulatory effects of a constant titre of anti-sheep erythrocyte (SRBC) antibodies collected during primary and secondary responses and separated according to class, as well as monoclonal antibodies of the same isotypes, were compared by studying the specific and total plaque-forming cell (PFC) responses to the simultaneous administration of antigen. Polyclonal secondary IgG1 antibodies were found unique in their ability to suppress completely specific PFC responses. Polyclonal secondary antibodies of other IgG subclasses, polyclonal primary IgG1 and monoclonal IgG1 antibodies, all were found at the same titre either totally ineffective or mediating very litte suppression. Primary polyclonal IgM antibodies were also found much superior to monoclonal antibodies and to secondary polyclonal IgM antibodies in their ability to enhance specific responses and largely augment the total number of Ig PFC in the spleen. While these results are most easily interpreted by postulating a primary determination of regulatory properties by V-regions, we could not find evidence for "allotype-restriction" of these effects.

Animals↗