Simultaneous alveolar and cystic echinococcosis of the liver

Co-Occurrence of Cystic and Alveolar Echinococcosis in the Liver: A Case Report

Morbidity of mixed cystic and alveolar echinococcosis (CE and AE) is exceptionally rare. Less literature retrieved from a database on the internet detailed the content, including radiography, pathology, and therapeutics data. Such a case of co-occurrence of the different Echinococcus species was diagnosed and treated at our hospital center from Nov 2019 to Feb 2020. A 30 yr old female from the pastoral area in Qinghai Province, China, was diagnosed with a case of echinococcosis and diagnosis was confirmed after image studies, immunoassaying of hydatid enzymes, life history and pathology result. The patient underwent hepatectomy along with excision of the internal capsule. Post-operative pathology was done, and it confirmed a mixed infection of both CE and AE. The patient recovered well without complications after liver-protecting and tissue repair treatment for 15 days. Knowing about infective mode and immune method of the case might be vital for research on variation for Echinococcus infection.

Multiple haplotypes of Echinococcus granulosus sensu stricto in single naturally infected intermediate hosts

Cystic echinococcosis is a disease that affects both humans and animals, caused by cryptic species complex belonging to the platyhelminth Echinococcus granulosus sensu lato (s.l.). This disease is distributed worldwide, with E. granulosus sensu stricto (s.s.) being the most widespread of the species. High genetic variability has been demonstrated within E. granulosus s.s. studying single cyst per infected animal identifying a number of different haplotypes. However, few studies have addressed the genetic diversity of this parasite within a single intermediate host with multiple Echinococcus cysts. To date, it remains unknown if specific haplotypes of E. granulosus s.s. produce differences in biological features of the cyst. Here, we use the full length of the mitochondrial gene cox1 to determine E. granulosus s.s. haplotypes in samples from both cattle and sheep which harboured more than one cyst in different areas in Chile, where this parasite is endemic. We found 16 different haplotypes in 66 echinococcal cysts from 10 animals, and both cattle and sheep can harbour up to five different haplotypes of E. granulosus s.s. in the same animal. Regarding cyst fertility, five animals had both fertile and infertile Echinococcus cysts in both single and multiple haplotype infections. There was no association between haplotype and cyst fertility, size, or adventitial layer characteristics. Sampling and sequencing every Echinococcus cyst found in the intermediate host reveals a high molecular variability. We speculate that multiple haplotype infections could also suggest that intermediate hosts come from hyperendemic areas.

Simultaneous occurrence of hepatic alveolar and cystic echinococcosis

The co-occurrence of hepatic cystic echinococcosis (CE) and alveolar echinococcosis (AE) is extremely rare. Here, we present the clinical manifestations and treatment outcomes of three cases with co-occurring CE and AE in the liver. Computed tomography (CT), magnetic resonance imaging and 18FFluorodeoxyglucose Positron Emission Tomography-CT were used for preoperative diagnosis. Specimens were taken intraoperatively and sent for pathological studies to confirm the coexistence of CE and AE by laminated membrane, daughter cysts or germinal layer and infiltration structure. Albendazole was prescribed after operation for 12 months. All patients were completely recovered and showed no recurrence at last follow-up. Therefore, surgical intervention and postoperative application of albendazole are recommended for patients with concurrence of hepatic AE and CE.

Genetic Profile of Hydatid Cysts in Patients with Multi-Organ Involvement: Mixed Infections by Different Strains

Our knowledge on the susceptibility of humans to different genotypes of the zoonotic tapeworm Echinococcus granulosus and the genetic make-up of the cysts in multi-organ involvements is limited. This study aimed to identify the genotype profile of E. granulosus in patients undergoing hydatid surgery in an endemic area for cystic echinococcosis (CE) in southeastern Iran. Individuals who underwent hydatid cyst surgery were included in this study. Protoscoleces/germinal layers from each individual isolate were washed and kept in -20°C until use. Genotyping was carried out using PCR-sequencing of two mitochondrial CO1 and ND1 genes. Molecular phylogeny and haplotype network analysis of the human isolates were carried out using sequence data obtained from this study and National Center for Biotechnology Information (NCBI) databases. Forty-two patients (23 women and 19 men) participated in the study; the mean age was 43 years. Eighteen (42.9%) and 24 (57.1%) patients were infected by E. granulosus sensu stricto (G1-G3) and Echinococcus intermedius (G6 genotype), respectively. Molecular study showed mixed infection of G1 (in the liver and right lung) and G6 (in left lung) in a patient. The study showed a significantly high proportion of CE patients infected with the G6 genotype particularly in the southern parts of the province. In the present study a human CE patient infected by two species/genotypes of E. granulosus sensu lato is documented.

The echinococcoses in Asia: The present situation

Human alveolar and cystic echinococcosis, caused by the accidental ingestion of eggs of the tapeworms Echinococcus multilocularis and Echinococcus granulosus sensu lato, respectively, are endemic in Asia. Various Echinococcus species are maintained in domesticated and/or wild mammals through predator-prey interactions. Molecular analysis is used to help differentiate infecting parasite species and genotypes, with the goal of better understanding parasite life cycles in order to aid in the planning and implementation of control programs. This paper discusses the various echinococcoses in Asia, with limited reference to neighboring areas, including parts of Central Asia, Russia, Europe and North America.

Human cystic and alveolar echinococcosis in the Tibet Autonomous Region (TAR), China

Human cystic echinococcosis (CE) is known to be endemic in the Tibet Autonomous Region (TAR), China; however, there is relatively little data from hospital records or community prevalence studies, and the situation regarding occurrence of human alveolar echinococcosis (AE) is unclear. Here we review the available reports about human echinococcosis in the seven prefectures of TAR. In addition, two pilot studies by mass screening using ultrasound (with serology) were undertaken (2006/7) in Dangxiong County of Lhasa Prefecture (north central TAR) and Dingqing County of Changdu Prefecture (eastern TAR). In Dangxiong County a prevalence of 9.9% (55/557) for human CE was obtained but no human AE cases were detected. By contrast, in Dingqing County (N= 232 persons screened), 11 CE cases (4.7%) and 12 AE cases (5.2%) (including one mixed CE and AE case) were diagnosed by ultrasound. Hospital records and published reports indicated that CE cases were recorded in all of seven prefectures in Tibet Autonomous Region, and AE cases in four prefectures. Incidence rates of human CE were estimated to range from 1.9 to 155 per 100,000 across the seven prefectures of TAR, with a regional incidence of 45.1 per 100,000. Incidence of AE was estimated to be between 0.6 and 2.8 cases per 100,000. Overall for TAR, human AE prevalence appeared relatively low; however, the pilot mass screening in Dingqing in eastern TAR indicated that human AE disease is a potential public health problem, possibly similar to that already well described in Tibetan communities bordering TAR in north-west Sichuan and south-west Qinghai provinces.

Immunogenetics of human echinococcosis

Susceptibility and resistance to human Echinococcus infection and disease, although poorly understood, appear to reflect a complex interaction of parasite and host immunological and genetic factors. Disease stage, progression, and prognosis following treatment appear to be strongly influenced by cytokine and antibody profiles, and more recent evidence has suggested an important role of dendritic cells (DCs) and T regulatory cells (Tregs) in immunomodulation. Microarrays have supported these findings, highlighting both known and novel pathways involved in chronic murine disease. Genetic studies to date have been few and with limited success. Advanced genomic approaches, such as genome-wide association studies (GWAS), may provide further insight to identify the relevant pathways involved, thereby facilitating a new approach for the development of new clinical therapies.

Clinical features and treatment of alveolar echinococcosis

PURPOSE OF REVIEW

Human alveolar echinococcosis is caused by the larval stage of Echinococcus multilocularis, occurring in at least 42 countries of the northern hemisphere. Recent studies in Europe and Asia have shown that the endemic area of E. multilocularis is larger than previously known and the parasite has regionally expanded from rural to urban areas. Diagnosis of alveolar echinococcosis is supported by results from imaging studies, histopathology and/or nucleic acid detection, and serology. The present review summarizes current understanding of clinical features, knowledge on appropriate treatment, and discusses ways to improve standards of care.

RECENT FINDINGS

High prevalences of this deadly disease have been discovered in surveys in parts of China. Clinical manifestations, diagnostic tools and the burden of disease were described, and are based on high case numbers. In Europe, excellent tools have been introduced, which improve disease management. Long-term observations in Switzerland provide an optimistic view, as the infection can be well controlled, if patients are cared for in specialized centres. An expert consensus summarizes the current recommendation for diagnosis and treatment of alveolar echinococcosis by the Informal Working Group on Echinococcosis of the WHO.

SUMMARY

Diagnosis and treatment of alveolar echinococcosis remains a challenge for clinicians. The updated WHO-recommendations aim to support decisions on diagnosis and treatment of alveolar echinococcosis. Anti-infective therapy is the backbone of treatment; surgery should be restricted to patients at an early stage of the disease. For the majority of cases continuous chemoprophylaxis with benzimidazoles is cost-effective and leads to a good quality of life for patients with this chronic disease.

Failure to observe cross-fertilization between the Echinococcus granulosus G1 and G6 strains after an experimental mixed infection of the definitive host

The classification within Echinococcus granulosus is currently under debate. To assess the reproductive potential between the G1 and G6 strains, an experimental double infection was carried out in a dog. First, two fertile hydatid cysts were collected in Algeria from a cow and a dromedary. They were identified as being G1 and G6 with the markers coxI and nadI. Subsequently, a dog was inoculated with protoscoleces from these two cysts. Sixty days after infection, 85 adult worms were recovered from the intestine of the dog. Then, the two cysts and each of these individual parasites were characterized with the multilocus microsatellite EmsB and compared. For all worms, the scolex and the gravid proglottids, separately analyzed, provided an identical profile: the G1 profile was observed in 70 adults, and the G6 profile in the 15 others. No single worm exhibited a hybrid G1/G6 profile. This result suggests the absence of cross-fertilizing between the two taxa under the given experimental conditions, and so, the presence of a strong cross-reproductive barrier. This observation corroborates with the recent reclassification of G1 and G6 within two distinct species.

Dot immunogold filtration assay (DIGFA) with multiple native antigens for rapid serodiagnosis of human cystic and alveolar echinococcosis

A new 3-min rapid dot immunogold filtration assay (DIGFA) for serodiagnosis of human cystic and alveolar echinococcosis was developed using four native antigen preparations: crude and partially purified hydatid cyst fluid extracts from Echinococcus granulosus (EgCF and AgB), E. granulosus protoscolex extract (EgP) and Echinococcus multilocularis metacestode antigen (Em2). The overall sensitivity of DIGFA in a hospital diagnostic setting was 80.7% for human cystic echinococcosis (CE) (n=857) and 92.9% for human alveolar echinococcosis (AE) (n=42). Highest specificity was 93.4% with AgB extract for CE, and 90.3% with Em2 antigen for AE when CE versus AE cross-reactivity was excluded. Anti-AgB antibodies were present in 35.5% of AE cases and anti-Em2 in 7.4% of CE cases. In endemic communities in northwest China screened for echinococcosis, the sensitivity of DIGFA ranged from 71.8% to 90.7% in comparison to abdominal ultrasound; specificity for CE using AgB was 94.6% and for AE using Em2 was 97.1%. This simple eye-read rapid test can be used for both clinical diagnostic support, as well as in conjunction with ultrasound for mass screening in endemic CE and AE areas.

Human cases of simultaneous echinococcosis and tuberculosis - significance and extent in China

During analysis of retrospective community survey data, we identified two patients from Xiji County, south Ningxia Hui Autonomous Region with simultaneous echinococcosis and tuberculosis (TB), representing the first such reports for China. As the echinococcosis chronicity increased, the immune profile in both subjects changed from a Th1 to Th2 response, as shown by a TB skin test, originally positive, becoming negative. Such an elevated Th2 immune profile, with subsequent suppression of the Th1 immune response, is a common feature of chronic helminth infections. Given the difficulties in definitive diagnosis, and the potential increased susceptibility for TB infection in patients with advanced echinococcosis, we suggest that combined TB/echinococcosis surveys be undertaken in this area in the future. This would allow early diagnosis of both TB and echinococcosis cases with better prognosis for effective and sustainable treatment outcomes, ultimately reducing associated morbidity and mortality, and also the overall financial costs to the individual and the public health care system in this under developed part of China.

A correlative study of ultrasound with serology in an area in China co-endemic for human alveolar and cystic echinococcosis

We correlated ultrasound (US) imaging classifications for human alveolar echinococcosis (AE) and cystic echinococcosis (CE) with serology (ELISA and immunoblotting (IB) incorporating native and recombinant/purified echinococcal antigens) in community surveys (2001-2003) and follow-up (2002 and 2003) of US-confirmed cases in Ningxia, China. One hundred and seventy-one cases (96 with AE, 75 with CE) were identified; of these, US classification and serological data were obtained for 142 and 112 cases, respectively. Seropositive-rates increased in CE patients with highly viable unilocular cyst lesions (Types CL, CE 1 or CE 2) to degenerating primary lesions (CE 3), but then decreased in subjects with inactive (CE 4) or dead (CE 5) cysts. In contrast, there was a constant increase in seropositivity from the early (P1, P2) to the advanced stages (P3, P4) with AE cases. For US-confirmed cases, follow-up by US combined with serology is invaluable for studying the clinical progression of echinococcosis and for detecting recurrent cysts or reinfection post-treatment.

Epidemiology of human alveolar echinococcosis in China

Globally human alveolar echinococcosis (AE) is a rare zoonotic helminthic disease confined to the Northern Hemisphere as sporadic infections in rural populations, principally in some areas of North America, west-central Europe, the Near East, Siberia, Central Asia, Japan and China. In China the first human cases were reported from western regions in the 1960s, but most hospital records remain fragmented and inadequate. From the mid-1990s mass screening surveys using portable ultrasound scanners recorded higher prevalences (up to 6% by county) than in any other areas of the world with some village rates as high as 15%. Risk factors identified for AE cases included ethnicity, sex, age and occupation. The role of the dog in transmission of Echinococcus multilocularis to humans now appears to be significant and may be one of the most important risk factor, in combination with landscape/land-use features conducive to maintaining wildlife host populations.