Comparison of real-time PCR and the Kato-Katz method for the diagnosis of soil-transmitted helminthiasis and assessment of cure in a randomized controlled trial.

BACKGROUND: Diagnosis of soil-transmitted helminths (STHs) in developing countries is commonly based on microscopic detection of eggs in stool samples, using the Kato-Katz (KK) method, which has a poor sensitivity for detecting light intensity infections. We compared the performance of the KK method and real-time PCR in the framework of a randomized trial, which evaluated four novel treatments against Trichuris trichiura and concomitant STH infections. RESULTS: Two stool samples obtained from 320 participants were examined at baseline and follow-up with quadruplicate KK and PCR analyses of one of the two samples using "bead-beating" for DNA extraction. At follow-up, 80 samples were negative according to both PCR and KK and 173 were positive with both methods for any of the STHs. Relative to PCR, the calculated sensitivity of KK at follow-up was 83.6%, 43.0% and 53.8% for T. trichiura, for hookworm and for Ascaris lumbricoides, respectively. The sensitivity of PCR compared with KK at this time point was 89.1% for T. trichiura, 72.7% for hookworm and 87.5% for A. lumbricoides. Cure rates (CRs) for T. trichiura and A. lumbricoides were slightly lower with the PCR method. For hookworm CRs with KK were mostly significantly lower, namely 36.7%, 91.1%, 72.2% and 77.8% for moxidectin, moxidectin in combination with tribendimidine, moxidectin in combination with albendazole and albendazole in combination with oxantel pamoate, respectively, whereas with PCR the CRs were 8.3%, 82.6%, 37.1% and 57.1%, respectively. CONCLUSIONS: In conclusion, a single real-time PCR is as sensitive as quadruplicate KK for T. trichiura and A. lumbricoides detection but more sensitive for hookworm, which has an influence on the estimated treatment efficacy. PCR method with DNA extraction using the "bead-beating protocol" should be further promoted in endemic areas and laboratories that can afford the needed equipment. The study is registered at ISRCTN (no. 20398469).

Efficacy of single-dose 500 mg mebendazole in soil-transmitted helminth infections: a review.

Soil-transmitted helminthiasis (STH) is caused by Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm), and Ancylostoma duodenale and Necator americanus (hookworms). Mebendazole is one of the recommended preventive chemotherapy agents for STH. This review summarizes the efficacy data from 29 studies with single-dose 500 mg mebendazole in STH treatment and compares the results with those of a recently conducted phase 3 study of a 500 mg mebendazole chewable tablet against A. lumbricoides and T. trichiura infections. Studies that reported efficacy results against at least one STH infection were selected from the literature and efficacy data by each STH type were abstracted and pooled. Single-dose 500 mg mebendazole treatment resulted in a cure rate of 92.6% (range: 72.5-100%) for A. lumbricoides, 27.6% (range: 8.4-100%) for T. trichiura and 25.5% (range: 2.9-91.1%) for hookworms. Egg reduction rate for A. lumbricoides was 97.9% (range: 89.8-100%), for T. trichiura it was 72.9% (range: 31.6-93.0%) and for hookworms it was 72.0% (range: -6.5% (denoting an increase in egg count) to 98.3%). Similar results were observed in the studies that were placebo-controlled. In the phase 3 study, the cure rate and egg reduction rate reported was 83.7% and 97.9%, respectively, for A. lumbricoides and 33.9% and 59.7%, respectively, for T. trichiura. In conclusion, single-dose 500 mg mebendazole showed a high cure rate against A. lumbricoides and a substantial reduction in faecal egg count for all STH types. These results are consistent with the recently conducted phase 3 study of a new 500 mg chewable mebendazole tablet.

Muscle pain, fever, cough, and progressive dyspnea in a woman with eosinophilic pneumonia.

The diagnosis of eosinophilic pneumonia (EP) is rare and challenging. This condition is frequently misdiagnosed as pulmonary tuberculosis, lymphoma, schistosomiasis, Wegener's granuloma, severe acute respiratory syndrome, or severe community-acquired pneumonia. Herein, we report a case in which computed tomography (CT)-guided percutaneous lung biopsy was used to diagnose EP without alveolar eosinophilia or peripheral eosinophilia. A roundworm identified in the patient's stool confirmed the precise diagnosis to be parasitic EP. This is, to our knowledge, the first reported case of EP confirmed by CT-guided percutaneous lung biopsy. CT-guided percutaneous lung biopsy may represent a new tool for the diagnosis of EP in patients without typical alveolar eosinophilia or peripheral eosinophilia.

Randomized, controlled, assessor-blind clinical trial to assess the efficacy of single- versus repeated-dose albendazole to treat ascaris lumbricoides, trichuris trichiura, and hookworm infection.

In many regions where soil-transmitted helminth infections are endemic, single-dose albendazole is used in mass drug administration programs to control infections. There are little data on the efficacy of the standard single-dose administration compared to that of alternative regimens. We conducted a randomized, controlled, assessor-blinded clinical trial to determine the efficacies of standard and extended albendazole treatment against soil-transmitted helminth infection in Gabon. A total of 175 children were included. Adequate cure rates and egg reduction rates above 85% were found with a single dose of albendazole for Ascaris infection, 85% (95% confidence interval [CI], 73, 96) and 93.8% (CI, 87.6, 100), respectively, while two doses were necessary for hookworm infestation (92% [CI, 78, 100] and 92% [CI, 78, 100], respectively). However, while a 3-day regimen was not sufficient to cure Trichuris (cure rate, 83% [CI, 73, 93]), this regimen reduced the number of eggs up to 90.6% (CI, 83.1, 100). The rate ratios of two- and three-dose regimens compared to a single-dose treatment were 1.7 (CI, 1.1, 2.5) and 2.1 (CI, 1.5, 2.9) for Trichuris and 1.7 (CI, 1.0, 2.9) and 1.7 (CI, 1.0, 2.9) for hookworm. Albendazole was safe and well tolerated in all regimens. A single-dose albendazole treatment considerably reduces Ascaris infection but has only a moderate effect on hookworm and Trichuris infections. The single-dose option may still be the preferred regimen because it balances efficacy, safety, and compliance during mass drug administration, keeping in mind that asymptomatic low-level helminth carriage may also have beneficial effects. (This study has been registered at ClinicalTrials.gov under registration number NCT01192802.).

Application of the Fenton process in the elimination of helminth eggs.

This study relates to a method for evaluating the degradation efficiency of Ascaris lumbricoides eggs through a Fenton reaction, using hydrogen peroxide (H2O2) at 100, 250, and 500 mg/L, ferrous sulfate (FeSO4) at 458 mg/L Fe(2+) and pH values of 3, 4.5, and 6. The experiments were conducted according to a 3(2) experimental design, with 1:1, 3:1, and 5:1 (H2O2/Fe(2+)) molar ratios. The oxidation and flocculation stages were performed at 130 rpm during 2 hours and at 25-30 rpm during 20 min, respectively. As a result of the Fenton reaction, an average of 91.2% Ascaris lumbricoides egg degradation was achieved at pH 6 using a 500 mg/L dose of H2O2 and a 3:1 (H2O2/Fe(2+)) molar ratio. Thus, this process is an alternative for eliminating parasites that are resistant to conventional disinfection processes and significantly reduces the human health hazard they represent.

Efficacy of albendazole against soil-transmitted helminth infections in Ethiopia: a systematic review and meta-analysis.

Soil-transmitted helminths (STH) are neglected parasites more prevalent in the tropics. Periodic mass distribution of albendazole, is one key strategy to control STHI in endemic areas. However, benzimidazoles have low efficacy against STHI, and there is a lack of information on the magnitude of the problem in Ethiopia. Articles were searched from PubMed using MeSH words, Google Scholar, Web of science, EMBASE and Scopus database to retrieve the data published and available until December 30, 2022. Totally, 107 published articles were retrieved. Only studies conducted in English that reported the efficacy of albendazole against STHI in any year and studies with more than fifty positive cases were included in the present study. The efficacy of albendazole was estimated by its cure rate and egg reduction rate. Excel software was used to extract the name of the authors, the total sample size, number of cured participants, treatment assessment time, STH parasite involved, the study area, and the year of publication. The pooled efficacy of albendazole against STHs was analyzed using comprehensive meta-analysis version 2.2 software. A total of 14 studies (13 for hookworm, 12 for Ascaris lumbricoides, and 12 for Trichuris trichiura) fulfilled the inclusion criteria for the present systematic review and meta-analysis. The total positives for hookworm, A. lumbricoides, and T. trichiura were 1253 (24.9%), 1570 (29.5%), and 1647 (30.6%), respectively. The overall pooled efficacy of albendazole was 92.2% (95% CI 86.2-98.9%) against hookworm, 97.7% (95% CI 96.3-98.6%) against A. lumbricoides, and 38.6% (95% CI 31.0-46.9%) against T. trichiura. In subgroup analysis, the efficacy of albendazole against hookworm was 93.4% (95% CI 85.1-97.2%) in Oromia, 96.7% (95% CI 93.8-98.2%) in Sidama, and 77.2% (95% CI 64.4-86.4%) in Amhara region. Its heterogeneity was high (I2 = 89.418). The efficacy of albendazole against A. lumbricoides was 98.3% (95% CI 97.0-99.0%) in Oromia and 96.63% (95% CI 93.2-98.3%) in Sidama region. Its heterogeneity was moderate (I2 = 41.5%). Albendazole efficacy against T. trichiura was 39.0% (95% CI 30.4-48.5%) in Oromia and 37.8% (95% CI 21.8-56.9%) in Sidama region with high heterogeneity (I2 = 90.6%). In the present review, albendazole is effective against hookworm and A. lumbricoides but less effective against T. trichiura. Albendazole should therefore be used as a treatment option in hookworm and A. lumbricoides endemic areas. However, alternative drugs should be sought for T. trichiura.

Characterization of the ß-tubulin gene family in Ascaris lumbricoides and Ascaris suum and its implication for the molecular detection of benzimidazole resistance.

BACKGROUND: The treatment coverage of control programs providing benzimidazole (BZ) drugs to eliminate the morbidity caused by soil-transmitted helminths (STHs) is unprecedently high. This high drug pressure may result in the development of BZ resistance in STHs and so there is an urgent need for surveillance systems detecting molecular markers associated with BZ resistance. A critical prerequisite to develop such systems is an understanding of the gene family encoding ß-tubulin proteins, the principal targets of BZ drugs. METHODOLOGY AND PRINCIPAL FINDINGS: First, the ß-tubulin gene families of Ascaris lumbricoides and Ascaris suum were characterized through the analysis of published genomes. Second, RNA-seq and RT-PCR analyses on cDNA were applied to determine the transcription profiles of the different gene family members. The results revealed that Ascaris species have at least seven different ß-tubulin genes of which two are highly expressed during the entire lifecycle. Third, deep amplicon sequencing was performed on these two genes in more than 200 adult A. lumbricoides (Ethiopia and Tanzania) and A. suum (Belgium) worms, to investigate the intra- and inter-species genetic diversity and the presence of single nucleotide polymorphisms (SNPs) that are associated with BZ resistance in other helminth species; F167Y (TTC>TAC or TTT>TAT), E198A (GAA>GCA or GAG>GCG), E198L (GAA>TTA) and F200Y (TTC>TAC or TTT>TAT). These particular SNPs were absent in the two investigated genes in all three Ascaris populations. SIGNIFICANCE: This study demonstrated the presence of at least seven ß-tubulin genes in Ascaris worms. A new nomenclature was proposed and prioritization of genes for future BZ resistance research was discussed. This is the first comprehensive description of the ß-tubulin gene family in Ascaris and provides a framework to investigate the prevalence and potential role of ß-tubulin sequence polymorphisms in BZ resistance in a more systematic manner than previously possible.

Impact of repeated four-monthly anthelmintic treatment on Plasmodium infection in preschool children: a double-blind placebo-controlled randomized trial.

BACKGROUND: Helminth infections can alter susceptibility to malaria. Studies need to determine whether or not deworming programs can impact on Plasmodium infections in preschool children. METHODS: A double-blind placebo-controlled randomised trial was conducted to investigate the impact of anthelmintic treatment on Plasmodium infection in children aged 12-59 months. Children were randomly assigned to receive either albendazole or placebo every four months for 12 months with a follow-up at 14 months. RESULTS: 320 Children (out of 1228, 26.1%) complied with all the follow-up assessments. Plasmodium prevalence and mean Plasmodium parasite density was significantly higher in the treatment group (44.9% and 2319 ± SE 511) compared to the placebo group (33.3% and 1471 ± 341) at baseline. The odds of having Plasmodium infection increased over time for children in both the placebo and treatment groups, however this increase was significantly slower for children in the treatment group (P = 0.002). By month 14, mean Plasmodium density had increased by 156% in the placebo group and 98% in the treatment group but the rate of change in Plasmodium density was not significantly different between the groups. The change from baseline in haemoglobin had a steeper increase among children in the treatment group when compared to the placebo group but this was not statistically significant. CONCLUSIONS: Repeated four-monthly anthelminthic treatments for 14 months resulted in a significantly lower increase in the prevalence of Plasmodium infection in preschool children which coincided with a reduction in both the prevalence and intensity of A. lumbricoides infections. TRIAL REGISTRATION: Current controlled trials ISRCTN44215995.

Low-dose beta-carotene supplementation and deworming improve serum vitamin A and beta-carotene concentrations in preschool children of Bangladesh.

Despite the national vitamin A and antihelminthic prophylaxis programmes, both intestinal geohelminths and subclinical vitamin A deficiency continue to be prevalent among children in developing countries. Studies on potential synergistic effects of vitamin A supplementation and deworming on retinol status have inconsistent results. The purpose of the present study was to investigate the impacts of low-dose beta-carotene supplementation and antihelminthic therapy on serum retinol and beta-carotene concentrations in preschool children of Bangladesh. Two hundred and forty-four children, known to be infected with Ascaris lumbricoides, were randomized into four treatment groups: I-IV. Group I and II received two oral doses of 400 mg of albendazole each, the first dose at baseline and the second dose after four months; Group III and IV received placebo in place of albendazole. In addition, Group I and III received 1.2 mg of beta-carotene powder in capsule daily for six months, and Group II and IV received placebo in place of beta-carotene. Serum retinol and beta-carotene levels were measured before and after six months of the interventions. Serum retinol and beta-carotene increased significantly in Group I where both antihelminthic therapy and daily beta-carotene supplementation were given (p<0.05 and p<0.001 respectively). Antihelminthic therapy alone only improved serum beta-carotene concentration (p<0.0001). Low-dose beta-carotene supplementation, along with an antihelminthic therapy, synergistically improved vitamin A status. This finding has public-health implications for improving vitamin A status of children in developing countries.

Whipworm and roundworm infections.

Trichuriasis and ascariasis are neglected tropical diseases caused by the gastrointestinal dwelling nematodes Trichuris trichiura (a whipworm) and Ascaris lumbricoides (a roundworm), respectively. Both parasites are staggeringly prevalent, particularly in tropical and subtropical areas, and are associated with substantial morbidity. Infection is initiated by ingestion of infective eggs, which hatch in the intestine. Thereafter, T. trichiura larvae moult within intestinal epithelial cells, with adult worms embedded in a partially intracellular niche in the large intestine, whereas A. lumbricoides larvae penetrate the gut mucosa and migrate through the liver and lungs before returning to the lumen of the small intestine, where adult worms dwell. Both species elicit type 2 anti-parasite immunity. Diagnosis is typically based on clinical presentation (gastrointestinal symptoms and inflammation) and the detection of eggs or parasite DNA in the faeces. Prevention and treatment strategies rely on periodic mass drug administration (generally with albendazole or mebendazole) to at-risk populations and improvements in water, sanitation and hygiene. The effectiveness of drug treatment is very high for A. lumbricoides infections, whereas cure rates for T. trichiura infections are low. Novel anthelminthic drugs are needed, together with vaccine development and tools for diagnosis and assessment of parasite control in the field.

Serious limitations of the current strategy to control Soil-Transmitted Helminths and added value of Ivermectin/Albendazole mass administration: A population-based observational study in Cameroon.

BACKGROUND: Soil-transmitted helminth (STH) infections remain a public health concern in sub-Saharan Africa. School-based mass drug administration (MDA) using the anthelminthic drug Mebendazole/Albendazole have succeeded in controlling morbidity associated to these diseases but failed to interrupt their transmission. In areas were filarial diseases are co-endemic, another anthelminthic drug (Ivermectin) is distributed to almost the entire population, following the community-directed treatment with ivermectin (CDTI) strategy. Since Ivermectin is a broad spectrum anthelmintic known to be effective against STH, we conducted cross-sectional surveys in two health districts with very contrasting histories of Ivermectin/Albendazole-based PC in order to investigate whether CDTI might have contributed in STH transmission interruption. METHODOLOGY: Cross-sectional surveys were conducted in two health districts with similar socio-environmental patterns but with very contrasting CDTI histories (Akonolinga health district where CDTI was yet to be implemented vs. Yabassi health district where CDTI has been ongoing for two decades). Stool samples were collected from all volunteers aged >2 years old and analyzed using the Kato-Katz technique. Infections by different STH species were compared between Akonolinga and Yabassi health districts to decipher the impact of Ivermectin/Albendazole-based MDA on STH transmission. PRINCIPAL FINDINGS: A total of 610 and 584 participants aged 2-90 years old were enrolled in Akonolinga and Yabassi health districts, respectively. Two STH species (Ascaris lumbricoides and Trichuris trichiura) were found, with prevalence significantly higher in Akonolinga health district (43.3%; 95% CI: 38.1-46.6) compared to Yabassi health district (2.5%; 95% CI: 1.1-5.1) (chi-square: 90.8; df: 1; p < 0.001). CONCLUSION/SIGNIFICANCE: These findings (i) suggest that Mebendazole- or Albendazole-based MDA alone distributed only to at-risk populations might not be enough to eliminate STH, (ii) support the collateral impact of Ivermectin/Albendazole MDA on A. lumbricoides and T. trichiura infections, and (iii) suggest that Ivermectin/Albendazole-based PC could accelerate STH transmission interruption.

The impact of four years of semiannual treatments with albendazole alone on lymphatic filariasis and soil-transmitted helminth infections: A community-based study in the Democratic Republic of the Congo.

BACKGROUND: The World Health Organization now recommends semiannual mass drug administration (MDA) of albendazole with integrated vector management as an option for eliminating lymphatic filariasis (LF) in areas of loiasis-endemic countries where it may not be safe to use diethylcarbamazine or ivermectin in MDA programs. However, the published evidence base to support this policy is thin, and uptake by national programs has been slow. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a community trial to assess the impact of semiannual MDA on lymphatic filariasis and soil-transmitted helminth infections (STH) in two villages in the Bandundu province of the Democratic Republic of the Congo with moderately high prevalences for LF and hookworm infections. MDA with albendazole was provided every six months from June 2014 to December 2017 with treatment coverages of the eligible population (all ≥ 2 year of age) that ranged between 56% and 88%. No adverse effects were reported during the trial. Evaluation at 48 months, (i.e. 6 months after the 8th round of MDA), showed that W. bancrofti microfilaremia (Mf) prevalence in the study communities had decreased between 2014 to 2018 from 12% to 0.9% (p<0.001). The prevalence of W. bancrofti antigenemia was also significantly reduced from 31.6% to 8.5% (p<0.001). MDA with albendazole also reduced hookworm, Ascaris lumbricoides and Trichuris trichiura infection prevalences in the community from 58.6% to 21.2% (p<0.001), from 14.0% to 1.6% and 4.1% to 2.9%, respectively. Hookworm and Ascaris infection intensities were reduced by 93% (p = 0.02) and 57% (p = 0.03), respectively. In contrast, Trichuris infection intensity was not significantly reduced by MDA (p = 0.61) over this time period. CONCLUSION/SIGNIFICANCE: These results provide strong evidence that semiannual MDA with albendazole alone is a safe and effective strategy for LF elimination in Central Africa. Community MDA also had a major impact on STH infections.

Epidemiology and the effect of treatment of soil-transmitted helminthiasis in pregnant women in southern Thailand.

This study aimed to assess the current situation of STH in pregnant women, explore factors associated with STH and evaluate the effects of its treatment. A cohort study was conducted in four southernmost provinces. All pregnant women who presented at their first prenatal care visit at participating hospitals were interviewed by trained health care providers and their stool specimens were examined for Ascaris lumbricoides, Trichuris trichiura and hookworm eggs. Women with STH were treated with 400 mg of albendazole after 14 weeks of gestation and treatment outcomes were evaluated three weeks after treatment. Of 1,063 pregnant women, STH were detected in 190 patients (17.9%) without seasonal variation for a combined infection of 21.6%. Ascaris, hookworm and Trichuris were detected in 10.3, 5.7 and 6.3%, respectively. The cure rate with a single dose was 92% but was 100% when repeated treatment was given as a three-day course. The risk of infection was higher in Muslim women, those with a family income < or = USD300/month, those bathing outside the house and those with no knowledge of STH. These results showed that southern Thailand is still an endemic area for STH and there appears to be no seasonal variation in incidence. Although the cure rate for treatment with albendazole was good, the low cure rate and egg reduction rate for trichuriasis needs to be considered.

First identification of the benzimidazole resistance-associated F200Y SNP in the beta-tubulin gene in Ascaris lumbricoides.

The main control strategy for Ascaris lumbricoides is mass drug administration (especially with benzimidazoles), which can select strains of parasites resistant to treatment. Mutations in the beta-tubulin isotype-1 gene at codons 167, 198 and 200 have been linked to benzimidazole resistance in several nematodes. The mutation in codon 200 is the most frequent in different species of parasites, as previously observed in Necator americanus and Trichuris trichiura; however, this mutation has never been found in populations of A. lumbricoides. This study aimed to screen for single nucleotide polymorphisms (SNPs) in the beta-tubulin isotype-1 gene at codon 200 in A. lumbricoides. We developed a technique based on an amplification refractory mutation system (ARMS-PCR) for the analysis of 854 single A. lumbricoides eggs collected from 68 human stool samples from seven Brazilian states. We detected the mutation in codon 200 at a frequency of 0.5% (4/854). This is the first report of this mutation in A. lumbricoides. Although the observed frequency is low, its presence indicates that these parasite populations have the potential to develop high levels of resistance in the future. The methodology proposed here provides a powerful tool to screen for the emergence of anthelmintic resistance mutations in parasitic nematode populations.

The optimal timing of post-treatment sampling for the assessment of anthelminthic drug efficacy against Ascaris infections in humans.

The egg reduction rate (ERR) is the current standard mean to assess the efficacy of drugs against human soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura and hookworm). Although the timing of post-treatment sampling is pivotal for a readily interpretation of drug efficacy, there is lack empirical data that allows recommending the optimal time point for a follow-up egg counting. In the present study, we re-analyzed both the kinetics of worm expulsion and egg output for Ascaris lumbricoides following a single oral dose of albendazole in a series of studies previously conducted in Kenyan communities. The results indicate that it takes up to 10 days post-treatment before the expulsion of both adult male and female Ascaris worms is completed, approximately 20% of the worms being expelled between day 7 and 10 post-treatment. The sequential analysis of the egg out put, indicated a poor ERR (89.4%) at day 7 post-treatment, but a 100% ERR at day 14 and 21 post-treatment. Based on our findings we recommend to wait at least 14 days after an albendazole treatment before conducting the follow-up egg count. Any sampling before this time point may result in biased ERR estimates, due the release of residual eggs from moribund or degenerating worms.

Seasonally timed treatment programs for Ascaris lumbricoides to increase impact-An investigation using mathematical models.

There is clear empirical evidence that environmental conditions can influence Ascaris spp. free-living stage development and host reinfection, but the impact of these differences on human infections, and interventions to control them, is variable. A new model framework reflecting four key stages of the A. lumbricoides life cycle, incorporating the effects of rainfall and temperature, is used to describe the level of infection in the human population alongside the environmental egg dynamics. Using data from South Korea and Nigeria, we conclude that settings with extreme fluctuations in rainfall or temperature could exhibit strong seasonal transmission patterns that may be partially masked by the longevity of A. lumbricoides infections in hosts; we go on to demonstrate how seasonally timed mass drug administration (MDA) could impact the outcomes of control strategies. For the South Korean setting the results predict a comparative decrease of 74.5% in mean worm days (the number of days the average individual spend infected with worms across a 12 month period) between the best and worst MDA timings after four years of annual treatment. The model found no significant seasonal effect on MDA in the Nigerian setting due to a narrower annual temperature range and no rainfall dependence. Our results suggest that seasonal variation in egg survival and maturation could be exploited to maximise the impact of MDA in certain settings.

Gallbladder ascariasis in Kosovo - focus on ultrasound and conservative therapy: a case series.

BACKGROUND: Ascaris lumbricoides is one of the most common intestinal infections in developing countries, including Kosovo. In contrast to migration to the bile duct, migration of the worm to the gallbladder, due to the narrow and tortuous nature of the cystic duct, is rare. When it does occur, it incites acalculous cholecystitis. CASE PRESENTATIONS: This case series describes a 16-month-old Albanian girl, a 22-month-old Albanian girl, a 4-year-old Albanian girl, and a 10-year-old Albanian boy. Here we report our experience with gallbladder ascariasis including clinical manifestations, diagnostic procedures, and treatment. Fever, diarrhea and vomiting, dehydration, pale appearance, and weakness were the manifestations of the primary disease. In all patients, a physical examination revealed reduced turgor and elasticity of the skin. Abdomen was at the level of the chest, soft, with minimal palpatory pain. The liver and spleen were not palpable. A laboratory examination was not specific except for eosinophilia. There were no pathogenic bacteria in coproculture but Ascaris was found in all patients. At an ultrasound examination in all cases we found single, long, linear echogenic structure without acoustic shadowing containing a central, longitudinal anechoic tube with characteristic movement within the gallbladder. Edema of the gallbladder wall was suggestive of associated inflammation. There were no other findings on adjacent structures and organs. All patients received mebendazole 100 mg twice a day for 3 days. They also received symptomatic therapy for gastroenteritis. Because of elevated markers of inflammation all patients were treated with antibiotics, assuming acute cholecystitis, although ultrasound was able to confirm cholecystitis in only two of our four patients. Since the length of stay was dependent on the primary pathology it was 7 to 10 days. At control ultrasounds on 14th day, third and sixth month, all patients were free of ascariasis. CONCLUSIONS: Gallbladder ascariasis should be considered in all patients presenting with abdominal pain, distension, colic, nausea, anorexia, and intermittent diarrhea associated with jaundice, nausea, vomiting, fever, and severe radiating pain. Eosinophilia, ova, and parasites on stool examination as well as an anechogenic tube with characteristic movement within the bile duct found on abdominal ultrasound are conclusive for diagnosis. Mebendazole is an effective drug for the treatment. Surgical treatment is rarely needed.

EUS of pancreatic ascariasis.

Ascaris is a common cause of acute pancreatitis in developing countries. The mechanism of ascariasis induced acute pancreatitis include obstruction of papilla of Vater, invasion of common bile duct, or pancreatic duct (PD). PD ascariasis is a rare diagnosis. Endoscopic ultrasound is a highly accurate method to diagnose the aetiology of idiopathic acute pancreatitis with reference to biliary and pancreatic ascariasis. Treatment usually consist of endoscopic removal of worms with dormia basket or forceps on side viewing endoscopy. Ascaris induced pancreatitis is generally mild and worm extraction is associated with rapid relief of symptoms. We present a case of PD ascariasis diagnosed on endoscopic ultrasound.

Helminth lifespan interacts with non-compliance in reducing the effectiveness of anthelmintic treatment.

BACKGROUND: The success of mass drug administration programmes targeting the soil-transmitted helminths and schistosome parasites is in part dependent on compliance to treatment at sequential rounds of mass drug administration (MDA). The impact of MDA is vulnerable to systematic non-compliance, defined as a portion of the eligible population remaining untreated over successive treatment rounds. The impact of systematic non-compliance on helminth transmission dynamics - and thereby on the number of treatment rounds required to interrupt transmission - is dependent on the parasitic helminth being targeted by MDA. RESULTS: Here, we investigate the impact of adult parasite lifespan in the human host and other factors that determine the magnitude of the basic reproductive number R 0 , on the number of additional treatment rounds required in a target population, using mathematical models of Ascaris lumbricoides and Schistosoma mansoni transmission incorporating systematic non-compliance. Our analysis indicates a strong interaction between helminth lifespan and the impact of systematic non-compliance on parasite elimination, and confirms differences in its impact between Ascaris and the schistosome parasites in a streamlined model structure. CONCLUSIONS: Our analysis suggests that achieving reductions in the level of systematic non-compliance may be of particular benefit in mass drug administration programmes treating the longer-lived helminth parasites, and highlights the need for improved data collection in understanding the impact of compliance.