Short report: long-term serum antibody isotype responses to Strongyloides stercoralis filariform antigens in eight patients treated with ivermectin

The enzyme-linked immunosorbant assay was used to investigate long term changes in serum immunoglobulin G1 (IgG1), IgG4, IgE, and IgA against Strongyloides stercoralis phosphate-buffered saline-soluble filariform larval antigens in eight Jamaican patients treated with ivermectin. Patients were followed for periods of between 170 and 542 days. Based on repeated formalin-ether concentration and agar plate culture, all patients were found to be uninfected up to 18 months following chemotherapy. Generally, all antibody isotype levels decreased following treatment, although there was considerable heterogeneity among patients. In a single patient with hyperinfection, the decrease in IgG4 was marginal and may represent a treatment failure. Reduction in serum antibody isotype responses to S. stercoralis following treatment may be used to assess the effectiveness of ivermectin in treating endemic strongyloides (AU)

Mass chemotherapy with diethylcarbamazine for the control of Bancroftian Filariasis: a twelve-year follow-up in Northern Trinidad, including observations on Mansonella Ozzardi

A microfilaria survey was conducted in Trinidad in 1992, 12 years after mass treatment with spaced doses of diethylcarbamazine citrate (DEC-C) for the control of Bancroftian filariasis; 348 persons were examined using thick blood smears and a membrane filtration technique. They included 104 who had participated in the mass chemotherapy campaign in 1980. No Wuchereria bancrofti microfilariae were detected among 66 percent of the population examined. In 1980, 86 of 592 persons examined were found to be infected with W. bancrofti, 140 with Mansonella ozzardi and 44 with mixed infections, while in 1992, only M. ozzardi infections persisted despite treatment with DEC-C. Of the 104 persons re-examined 12 years later, 46 had M. ozzardi, of which five were new cases, but none had W. bancrofti. During both the 1980 and 1992 surveys, low microfilariae rates for M. ozzardi were observed among those 19 years of age or younger. Of the 302 persons newly examined in 1992, 29 were infected with significantly (P<0.001) more males (79.3 percent) than females (20.9 percent) being microfilaremic. The combined results showed similiar prevalence rates for M. ozzardi from 23.3 percent to 21.6 percent in 1980 and 1992. Nucleopore membrane filtration and thick blood films were very efficient in demonstrating the presence of microfilariae. The usefulness of these methods and spaced treatment using DEC-C are also discussed (AU)

Significant reductions in the rates of gastrointestinal tract parasitic infections in children of St. Vincent over a thirteen-year period (1979-1992) - abstract

When 314 (1979) and 207 (1992) five- to nine-year old school children in St. Vincent were investigated for the presence of parasitic infections, there were significant reductions in the prevalence of trichuriasis (75 per cent to 21.7 per cent), ascariasis (37 per cent to 8.6 per cent), amoebiasis (9 per cent to 2.8 per cent) and giardiasis (10 per cent to 5.3 per cent) over the 13-year interval. Anthelminthic use remained at 63 - 65 per cent, but the brands of worm medicines taken changed over the period. Thus, whilst piperazine citrate was used by 41 per cent of the children in 1979, only 4.8 per cent of them used it in 1992. Albendazole which was used by a great majority (42.5 per cent) in 1992 was never used in 1979. Commensals were observed in 211 (67 per cent) children in 1979, and in 83 (40 per cent) children in 1992 (AU)

Helminthiasis in Montserrat after the parasite control programme and hurricane Hugo - abstract

The Parasite Control Programme of Montserrat, West Indies, was a child-targeted chemotherapeutic control programme which ran from August 1986 to July 1989. The Programme involved the delivery of a broad spectrum antihelminthic to children (2-15 years old) once every school term. Two months after the end of the Programme, Hurricane Hugo devastated Montserrat on September 17, 1989. The Health Department (Montserrat) felt that the reductions in prevalence and intensity of Trichuris trichiura and Ascaris lumbricoides gained as a result of the Programme would be compromised by the disruption to sanitation and water supply caused by Hugo. In December 1989, a cycle of treatment was therefore administered to the child target group using the same infrastructure and procedure as that used in the Control Programme. The treatment compliance was 97.0 percent of the student population (n=2,125). Six months later, an age-stratified survey was done to assess the level of infection in the population and the age-standardised prevalence of T. trichiura for the overall population. Changes in the age-standardised intensity of both helminths before and after Hugo were recorded for the overall population: for T. trichiura the intensity went from 0.8 to 1.5 epg-faeces, while for A. lumbricoides the intensity rose from 1.2 to 1.7 epg.faeces. The observed rise in the infection levels of the overall population not statistically significant. The changes seen in the prevalence and intensity of both parasites taken from the surveys before and after Hugo were all found to be non-significant. There appeared to have been a non-significant increase in parasitic infection levels 9 months after Hugo to levels seen in the latter part of the Control Programme (AU)

Refeeding the malnourished child: effect on the fecundity of trichuris trichiura and ascaris lumbricoides - abstract

Ten children with either Trichuris trichiura and/or Ascaris lumbricoides infection were admitted to the nutrition rehabilitation ward at the Tropical Metabolism Research Unit, U.W.I. Treatment with anthelminthic was delayed until the children attained their normal weight-for-height. Total daily stool output and changes in faecal egg density were monitored for each child, the latter by Kato analyses of sub-samples taken from all daily stools, from admission through to anthelminthic treatment. Worm burdens were then assessed by the collection of expulsions. The fecundity of the whipworm appeared not to be affected by dietary rehabilitation. However, roundworm fecundity decreased, in some instances to zero. In some cases, the roundworms were expelled during the course of refeeding. Refeeding was seen to have an antagonistic effect on the fecundity of A. lumbricoides. The fact that whipworm fecundity went unaltered may be an indication of modulation of the host immune response (AU)

Parasitic infections in young Jamaicans in different ecological zones of the island

Data are presented for the first country wide prospective study on gastrointestinal tract parasitic infections done in Jamaca. Samples from 2,947 young Jamaicans drawn from all ecological zones and from all parochial divisions of the island were analyzed. Pica was practised by 8.6 percent. Generally, prevalence of organisms was as follows: Trichiuris trichiura (12.3 percent). Ascaris lumbricoides (9.5 percent), hookworm (2.2 percent), Strongyloides stercoralis (0.35), Giardia lamblia (6.3 percent) and Entamoeba coli (7.7 percent). Several other species of protozoans were recorded. Prevalence of A. lumbricoides, T. trichiura and Necator americanus was significantly greater in upland than in lowland (both rual and urban), while the situation was reversed for G. lamblia-infections. Greatest variations were age-related. A.lumbricoides and T. trichiura reached peak prevalence of 15-19 years of age. Suggestions are made for a national and even regional antihelminthic program for the mass treatment of pre- and primary school age children. (AU)

Inactivation of strongyloides stercoralis filariform larvae in vitro by six Jamaican plant extracts and three commercial antihelminthics

In vitro bioassay of (a) aqueous methanol extracts (AME) of the green leaves of mimosa (Mimosa pudica), love weed (Cuscuta americana), vervine (Stachytarpheta jamaicensis), chicken weed (Salvia serotina) and breadfruit (Artocarpus altilis); (b) methanol-water fraction (MWF) of breadfruit leaves, and (c) commercially available drugs albendazole, thiabendazole and levamisole were assayed for nematode inactivating potential, using filariform larvae of Strongyloides stercoralis. Test larvae were obtained from a 10-day-old charcoal coproculture. Bioassays were conducted in Locke's solution, using 100 larvae in each of three replicates. Inactivation was recorded microscopically at 1, 2, 6 and 12 hours, then every 24 hours up to 5 days' incubation. It(50) (time for inactivation of 50 percent of larvae) values read: levamisole and mimosa extract < 1 hour; love weed extract, approximately 2 hours; breadfruit (MWF), 9.5 hours; chicken weed, 20 hours; albendazole, 35 hours; breadfruit (AME), 49 hours; thiabendazole, 74 hours and vervine extract, 81.5 hours. It(95) values followed a similar trend, and were approximately double the It(50) measures. A potential role for locally available natural products in the treatment of strongyloidiasis is highlighted (AU)

Parasitic infections in young Jamaicans in different ecological Zones in the Island - abstract

A gastrointestinal tract parasitological study was done on 2,947 young Jamaicans drawn from all ecological zones and from all parochial divisions of the island where pica was practised by 6.9 percent. Generally, the prevalence was Trichuris 12.3 percent, Ascaris 9.5 percent, Hookworm 2.2 percent, Strongyloides 0.3 percent, Giardia 6.3 percent and E. coli 7.7 percent. Several other spp. of protozoans were recorded. Prevalence of Ascaris, Trichuris and Necator was significantly greater in upland than in lowland areas, both urban and rural, while the situation was reversed for Giardia infections. Greatest variations in prevalence were age-related. Ascaris and Trichuris reached peak prevalences of 15.3 percent and 20.5 percent, respectively, in 5-9 year olds, while Hookworm peaked later at 15-19 years of age. Suggestions are made for a national, even a regional, antihelminthic programme for the mass treatment of pre- and primary school age children. This would aim at the eventual eradication of helminthiasis in the region (AU)

Rate of expulsion of Trichuris trichiura with multiple and single dose regimens of albendazole

The efficacy of multiple and single dose regimens of albendazole on Trichuris trichiura infection was evaluated by counting the number of worms expelled/day from two pair-matched groups of children, for nine days following therapy. The temporal patterns of worm expulsion were similar whether the children received a single 400 mg dose or two consecutive doses: no worms were passed before the second day, or after the sixth day, after intervention, and the maximum worm expulsion rate was attained on the fourth day. A second treatment six days after the first expelled no more worms. The results obtained here resemble those obtained previously with a three-day (600 mg) regimen of mebendazole in a study of heavily infected children. We conclude: that irrespective of dose, benzimidazole carbamates require the gut transit time plus 48 hours to immobilize T. trichiura; and that single dose of albendazole is effective against light infections of T. trichiura but requires further evaluation with high intensity infections.(AU)

Mebendazole: treatment of trichuriasis and ascariasis in Bahamian children

Mebendazole (Vermox), a new broad-spectrum anthelminthic, was used in 107 Bahamian children with trichuriasis, 88 of whom had concomitant ascariasis, in a dose of 100mg twice daily for three days. After treatment, three consecutive daily formalin-ether determinations and stool egg counts by the Stoll method were performed. Egg reduction rates of 97.6 percent and 99.5 percent were obtained for Trichuris trichiura and Ascaris Lumbricoides, respectively. Respective cure rates were 68.2 percent and 98.8 percent. Drug tolerance was excellent and side effects were nil. Mebendazole was confirmed as a safe and easily administered broad-spectrum anthelminthic, particularly useful in trichuriasis (AU)

Clinical trial of Hycanthone in Schistomiasis mansoni in St. Lucia

A clinical trial of a new antischistosomal drug, hycanthone methanesulfonate, was undertaken in 103 patients with schistosomiasis mansoni hospitalized in St. Lucia, West Indies. The drug was administered in a single intramuscular dose of 3mg per kg of body weight. The commonest side effect, vomiting, occurred in 48 patients (47 percent); 33 other patients complained of nausea, anorexia, or abdominal pain. In general, these symptoms ceased within 24 hours after treatment. Quantitative examination for Schistosoma mansoni eggs was carried out on three fecal specimens before treatment and at 6 weeks, 4 months, and 6 months after treatment. At 6 months after treatment, 26 of 94 patients (28 percent) were no longer excreting eggs, and 76 patients (81 percent) had sustained a greater than 90 percent reduction in egg-excretion level; for these 94 as a group, the total number of eggs excreted had been reduced by 97 percent. The efficacy of the drug did not appear to vary with severity of infection as measured by number of eggs excreted or by enlargement of the liver or spleen, or both. In this group of patients, two-thirds of whom were under 20 years of age, enlargement of the liver or spleen was frequently found to regress after treatment.(AU)

The diagnosis and treatment of human strongyloidiasis: a prospective study - abstract

A prospective hospital-based study evaluating the accuracy of diagnostic instruments in human strongyloidiasis is reported together with a reassessment of standard anti-helminthic therapy by strict criteria for cure. Eleven patients, 7 men and 4 women, whose ages ranged from 16 to 70 (median 53) years were studied before treatment. Four (1 man, 3 women) were assessed before 2 consecutive courses of treatment. The following tests were done: (1) formol-ether stool concentration, (2) Harada-Mori stool culture for 24 and 48 hours, direct microscopy of (3) duodenal aspirate and (4) duodenal mucosal biopsy, (5) duodenal mucosal biopsy histology, (6) examination for parsitic adults in stools collected over 48 hours after beginning treatment with thiabendazole (25 mg/kg twice daily) for 10 days. The results are given in the Table. Tests (1) - (5) were repeated 2 months after treatment, but Harada-Mori culture was continued for 7 days. Post-treatment assessment was completed in 9 of 11 patients (1 died, 1 default) and in 3 who were treated and assessed twice. Of 12 treatments, 9 failed (75 percent), although the number of parasites appeared reduced in all but 2 (17 percent). Results that was shown in the table as follows: TECHINQUE (n) are - Harada-Mori, Formol-ether, Duodenal aspirate, Mucosal Biopsy:(a) Microscopy, (b) Histology; SENSITIVITY ( percent) - PRE-TREATMENT (15):- 93, 87, 73, 53, 33 respectively; POST-TREATMENT (12):- 100, 67, 44, 33, 11 respectively. The Harada-Mori stool culture technique appears to be the single, most sensitive, diagnostic test. Although it may need to be supplemented with other tests to achive maximun diagnostic accuracym it is recommended that where strongyloidiasis is suspected, it becomes a standard diagnostic method. Formol-ether concentration is less sensitive in low-intensity infection. Previous studies from Jamaica have reported similarly low cure rate in contrast to those achieved in developed countries. Failure of treatment may indicate interaction between nutritional status and immuno-competence (AU)