Effect of Antischistosomal Chemotherapy on Prevalence of Symmers' Periportal Fibrosis in Sudanese Villages

Homeida, M.; Defalla, A.A; Kardaman, Mohamed; Nash, Theodore E.; Fenwick, Allyson M.; Suliman, Salwa; Eltom, I; Bennett, J.L.

doi:10.1016/s0140-6736(88)90424-2

Cited by 49 publications

(17 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[3][4][5] Periodic treatment with schistosomicidal drugs has greatly reduced the severe form of the disease, making it difficult to assess morbidity by clinical examination. 2,6,7 Since the primary objective of a control program should be the reduction and prevention of morbidity, it is important to evaluate the methods used to detect hepatic fibrosis. Ultrasonography has become a valuable tool in the assessment of morbidity due to S. mansoni infection.…”

Section: Introductionmentioning

confidence: 99%

Morbidity associated with Schistosoma mansoni infection determined by ultrasound in an endemic area of Brazil, Caatinga do Moura.

Jesus¹,

Miranda²,

Miranda³

et al. 2000

The American Journal of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Morbidity associated with Schistosoma mansoni infection determined by ultrasound in an endemic area of Brazil, Caatinga do Moura.

Jesus¹,

Miranda²,

Miranda³

et al. 2000

The American Journal of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

show abstract

“…1 In a number of regions, including much of Egypt, PZQ has been copiously used, and the impact of the drug on schistosome infections has been significant. 2,3 In the laboratory, exposure of schistosomes to subcurative doses of PZQ over generations resulted in drugresistant schistosomes, 4 demonstrating the possibility of resistance arising in the field. Indeed, reports of resistance in the field have recently appeared.…”

mentioning

confidence: 99%

Resistance to praziquantel: direct evidence from Schistosoma mansoni isolated from Egyptian villagers.

Ismail¹,

Botros²,

Metwally³

et al. 1999

The American Journal of Tropical Medicine and Hygiene

419

270

View full text Add to dashboard Cite

Abstract. Recent evidence suggest that resistance to praziquantel (PZQ) may be developing. This would not be surprising in countries like Egypt where the drug has been used aggressively for more that 10 years. The classic phenotype of drug resistance is a significant increase in the 50% effective dose value of isolates retrieved from patients not responding to the drug. In a previous publication, we reported that such phenotypes have been isolated from humans infected with Schistosoma mansoni. Since the action of PZQ may be dependent upon the drug and host factors, most notably the immune system, we analyzed the quantitative effects of PZQ on single worms that differed in their response to PZQ when maintained in mice. Our hypothesis was that the in vitro action of the drug would correlate with it in vivo action. We confirmed this hypothesis and conclude that the in vitro action of the drug is related to its in vivo action. Knowing this relationship will assist in our ability to detect or survey for the PZQ resistant phenotype in human populations.Praziquantel (PZQ) is used for the treatment of infections caused by Schistosoma spp. 1 In a number of regions, including much of Egypt, PZQ has been copiously used, and the impact of the drug on schistosome infections has been significant. 2,3 In the laboratory, exposure of schistosomes to subcurative doses of PZQ over generations resulted in drugresistant schistosomes, 4 demonstrating the possibility of resistance arising in the field. Indeed, reports of resistance in the field have recently appeared. 5 However, the reality of these reports is difficult to establish because it is often difficult to distinguish between host factors and parasite factors when patients are not cured of schistosomiasis with normally effective doses. First, since the host immune system plays an active role in the process of killing PZQ-damaged worms, 6 normal parasites might survive treatment in immunocompromised hosts. In vivo studies can also be confounded by the fact that PZQ is less effective in killing immature parasites, 7 such that a wide range of host factors inhibiting development of the parasites can cause an apparent decrease in drug efficacy. Variability of host PZQ metabolism can also cause variability of efficacy. 8 In an effort to minimize the variability of these host factors, parasites isolated from patients not cured by antischistosomal drugs have been used to establish experimental infections in less-variable laboratory animal hosts. 9 If infections produced by these isolates are not cured by normal doses of PZQ, it suggests that the decreased responsiveness of the isolates is due to worm factors rather than host factors. However, this type of assessment is a rather toilsome process.Despite the dependence of PZQ on the host immune system for killing the parasites in vivo, PZQ has dramatic, measurable effects on schistosomes in vitro. The three hallmark effects are contraction of the worm musculature, 10 an influx of calcium into the worm, 11 and disruption of the tegument...

show abstract

“…4 The presence and grade of esophageal varices was recorded in all subjects found to have schistosomal periportal fibrosis, as previously reported. 6 Because the level of infection was very high, we treated all inhabitants present at the first survey with praziquantel (Biltricide; Bayer AG, Leverkusen, Germany) in a single oral dose of 40 mg /kg.…”

Section: Study Plan Subjects and Methodsmentioning

confidence: 74%

“…Repeated mass chemotherapy is effective in preventing and perhaps reversing fibrosis in the early stage. 4,5 Antagonists of B-adrenoceptor have shown promising results in reducing mortality in advanced cases of periportal fibrosis. 15 Making these drugs available at an affordable price, together with other public health measures, remains a high priority in areas of endemic schistosomiasis.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Mortality due to schistosomiasis mansoni: a field study in Sudan.

Kheir¹,

Eltoum²,

Saad³

et al. 1999

The American Journal of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

Abstract. Although schistosomiasis affects 200 million persons, 20 million of whom have advanced disease, little is known about the mortality pattern in areas of endemic schistosomiasis mansoni. In an attempt to assess the mortality rates in an endemic area in Sudan, we conducted two demographic surveys in a village in the Gezira area. Clinical, sonographic, and parasitologic examinations were performed in a randomly selected sample of 25% of the population in 1987 and 1994. One of us asked each head of household about the names, sex, and age of family members. Particularly, we asked about death in the family if any, history of schistosomiasis, abdominal swelling, and hematemesis. Possible causes of death were ascertained by reviewing medical records in the village dispensary and the district hospital. There were 42 deaths in the village. Four males died of hematemesis secondary to portal fibrosis. The crude mortality rate of schistosomiasis was is 51/100,000/year. The overall schistosomiasis fatality rate per year was 1/1,000 infected persons, but was as high as 11/100/infected patients with bleeding varices. These findings showed the impact of schistosomiasis on public health in this economically important region of Sudan.

show abstract

Effect of Antischistosomal Chemotherapy on Prevalence of Symmers' Periportal Fibrosis in Sudanese Villages

Cited by 49 publications

References 7 publications

Morbidity associated with Schistosoma mansoni infection determined by ultrasound in an endemic area of Brazil, Caatinga do Moura.

Morbidity associated with Schistosoma mansoni infection determined by ultrasound in an endemic area of Brazil, Caatinga do Moura.

Resistance to praziquantel: direct evidence from Schistosoma mansoni isolated from Egyptian villagers.

Mortality due to schistosomiasis mansoni: a field study in Sudan.

Contact Info

Product

Resources

About