Echinococcosis in Pakistan: a call for research

Ultrasound identification of hepatic echinococcosis using a deep convolutional neural network model in China: a retrospective, large-scale, multicentre, diagnostic accuracy study

BACKGROUND

Ultrasonography is the most widely used technique to diagnose echinococcosis; however, challenges in using this technique and the demand on medical resources, especially in low-income or remote areas, can delay diagnosis. We aimed to develop a deep convolutional neural network (DCNN) model based on ultrasonography to identify echinococcosis and its types, especially alveolar echinococcosis.

METHODS

This retrospective, large-scale, multicentre study used ultrasound images from patients assessed at 84 hospitals in China, obtained between Jan 1, 2002, and Dec 31, 2021. Patients with a diagnosis of cystic echinococcosis, alveolar echinococcosis, or seven other types of focal liver lesions were included. We tested ResNet-50, ResNext-50, and VGG-16 as the backbone network architecture for a classification DCNN model and input the perinodular information from the ultrasound images. We trained and validated the DCNN model to diagnose and classify echinococcosis using still greyscale ultrasound images of focal liver lesions in four stages: differentiating between echinococcosis and other focal liver lesions (stage one); differentiating cystic echinococcosis, alveolar echinococcosis, and other focal liver lesions (stage two); differentiating cystic echinococcosis, alveolar echinococcosis, benign other focal liver lesions, and malignant focal liver lesions (stage three); and differentiating between active and transitional cystic echinococcosis and inactive cystic echinococcosis (stage four). We then tested the algorithm on internal, external, and prospective test datasets. The performance of DCNN was also compared with that of 12 radiologists recruited between Jan 15, 2022, and Jan 28, 2022, from Qinghai, Xinjiang, Anhui, Henan, Xizang, and Beijing, China, with different levels of diagnostic experience for echinococcosis and other focal liver lesions in a subset of ultrasound data that were randomly chosen from the prospective test dataset. The study is registered at ClinicalTrials.gov (NCT03871140).

FINDINGS

The study took place between Jan 1, 2002, and Dec 31, 2021. In total, to train and test the DCNN model, we used 9631 liver ultrasound images from 6784 patients (2819 [41·7%] female patients and 3943 [58·3%] male patients) from 87 Chinese hospitals. The DCNN model was trained with 6328 images, internally validated with 984 images, and tested with 2319 images. The ResNet-50 network architecture outperformed VGG-16 and ResNext-50 and was generalisable, with areas under the receiver operating characteristic curve (AUCs) of 0·982 (95% CI 0·960-0·994), 0·984 (0·972-0·992), and 0·913 (0·886-0·935) in distinguishing echinococcosis from other focal liver lesions; 0·986 (0·966-0·996), 0·962 (0·946-0·975), and 0·900 (0·872-0·924) in distinguishing alveolar echinococcosis from cystic echinococcosis and other focal liver lesions; and 0·974 (0·818-1·000), 0·956 (0·875-0·991), and 0·944 (0·844-0·988) in distinguishing active and transitional cystic echinococcosis from inactive echinococcosis in the three test datasets. Specifically, in patients with the hepatitis B or hepatitis C virus, the model could distinguish alveolar echinococcosis from hepatocellular carcinoma with an AUC of 0·892 (0·812-0·946). In identifying echinococcosis, the model showed significantly better performance compared with senior radiologists from a high-endemicity area (AUC 0·942 [0·904-0·967] vs 0·844 [0·820-0·866]; p=0·027) and improved the diagnostic ability of junior, attending, and senior radiologists before and after assistance with AI with comparison of AUCs of 0·743 (0·714-0·770) versus 0·850 (0·826-0·871); p<0·0001, 0·808 (0·782-0·832) versus 0·886 (0·864-0·905); p<0·0001, and 0·844 (0·820-0·866) versus 0·870 (0·847-0·890); p=0·092, respectively.

INTERPRETATION

The DCNN model was shown to be accurate and robust, and could improve the ultrasound diagnostic ability of radiologists for echinococcosis and its types for highly endemic and remote regions.

FUNDING

National Natural Science Foundation of China and National Key Research & Development Program of China.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

An Epidemiological Survey to Investigate the Prevalence of Cystic Echinococcosis in Slaughtered Bovine Hosts in Punjab, Pakistan

Cystic echinococcosis (CE) is a neglected zoonotic disease of worldwide geographical distribution. CE is most common in underdeveloped and herding communities where people survive on animal husbandry and agricultural activities. The prevalence of CE in livestock and its risk factors are widely underreported, because of inefficient surveillance systems. The aim of this study was to evaluate the epidemiological characteristics and prevalence of CE in cattle in Punjab, Pakistan. Data were collected from slaughterhouses from September 2021 to February 2022. Ante- and postmortem examination and cyst characterization were performed. Epidemiological, demographic, and one health data were collected. A total of 8877 animals (8096 buffalo, 781 cattle) were examined, and the prevalence of CE was 6.22% (n = 552) in all animals, with a higher prevalence in cattle (15.20% vs. buffalo 5.83%). Prevalence was not significantly different in males and females. Of the 23 districts studied, the highest prevalence was in the Haripur district of KP (20.85%). The majority of animals studied were older than 3 years. Most cysts were found in animals older than 5 years. Lungs and liver were the predominant sites for the presence of cysts (65.58% and 31.34%, respectively. Of the collected cysts, 29.71% were fertile. The findings may be useful in estimating the eco-epidemiology of CE and improving surveillance and prevention programs in Pakistan.

Genetic characterization of human echinococcosis in Southern Punjab, Pakistan

Introduction

Echinococcosis is a neglected tropical zoonotic infection that affects both the human and livestock populations. In Pakistan, the infection is long-standing, but data on its molecular epidemiology and genotypic characterization in the southern Punjab region are limited. The aim of the current study was the molecular characterization of human echinococcosis in southern Punjab, Pakistan.

Methods

Echinococcal cysts were obtained from a total of 28 surgically treated patients. Patients' demographic characteristics were also recorded. The cyst samples were subjected to further processing to isolate DNA in order to probe the Nad1 and Cyt-b genes, followed by DNA sequencing and phylogenetic analysis for genotypic identification.

Results

The majority of the echinococcal cysts were from male patients (60.7%). The liver was the most commonly infected organ (60.71%), followed by the lungs (25%), spleen (7.14%), and the mesentery (7.14%). Molecular and genotypic identification through sequencing and phylogenetic tree analysis showed that most of the cysts (24/28, 85.7%) were caused by the species Echinococcus granulosus sensu stricto (E. granulosus s.s.) (G1 and G3), followed by Echinococcus multilocularis (E. multilocularis) and Echinococcus canadensis (E. canadensis) (G6/G7) (3/28, 10.8%, and 1/28, 3.5%, respectively).

Conclusion

The current study concluded that the majority of human infections were caused by E. granulosus s.s., followed by the E. multilocularis and E. canadensis species (G6/G7). Genotypic characterization among both human and livestock populations is needed to explore the genetic diversity of echinococcosis.

Detection of Anti-Echinococcus granulosus Antibodies in Humans: An Update from Pakistan

Human cystic echinococcosis (CE) is a zoonotic disease caused by the larval stage of Echinococcus granulosus sensu lato that causes economic losses by affecting livestock and also poses a public health threat worldwide. The present study is the first retrospective report on the seroprevalence of anti-E. granulosus antibodies in humans in Pakistan. The study used data from 93 blood analysis reports of patients suspected of having CE from different medical centers in Lahore, Pakistan. Out of 93 sera samples, 20 (21.5%) were seropositive, and higher seropositivity (17.2%) was recorded with the indirect hemagglutination test (IHA) than with enzyme-linked immunosorbent assay (ELISA). The findings indicated that age, gender, and year had no significant relationship with the seropositivity of CE. The current study provides directions towards the management of the disease in the near future in Pakistan.

Estimation of the monetary burden of treated human cystic echinococcosis in Pakistan

Cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus sensu lato tapeworms, continues to be a public health problem in many endemic countries, including Pakistan. Patient level data, including age, sex, and cyst(s) location for surgically managed CE patients for the years 2013-2016 from hospitals located in Punjab and Khyber Pakhtunkhwa provinces were obtained from medical charts. Direct and indirect costs associated with surgically managed CE patients treated in private and public hospitals were then estimated and applied to country-level case numbers estimated through the Global Burden of Disease Study. A total cost of US$4,068,666 (95% CI: US$3,097,684 - US$5,295,702) was estimated for the year 2017, with US$3,951,853 (95% CI: US$2,981,400 - US$5,177,610) attributable to direct diagnosis and treatment-related costs and US$117,137 (95% CI: US$91,841 - US$146, 979) attributable to wage losses during the treatment period. Mean direct cost per patient (US$1,056) was approximately 72% of the country's per capita gross domestic product (GDP). Surgical management continues to be the treatment of choice for CE patients in Pakistan. If physicians were to adhere to World Health Organization Informal Working Group on Echinococcosis (WHO-IWGE) cyst stage-specific treatment guidelines, it is likely that the number of surgical interventions would decrease as would treatment costs.

Echinococcoses in Iran, Turkey, and Pakistan: Old Diseases in the New Millennium

Echinococcosis is considered a cosmopolitan zoonosis caused by different species of small taeniid tapeworms of the genus Echinococcus and is regarded as a neglected zoonosis. Cystic and alveolar echinococcoses are endemic diseases of Tibetan, Pamir, and Iranian plateaus. All of the countries within the Iranian plateau are affected by echinococcosis. Pakistan, Turkey, and Iran are the three most populous countries of the region, in which echinococcosis is highly endemic. The three neighboring countries share strong cultural and socioeconomic ties. The present study aimed to provide a broad review of the status of cystic and alveolar echinococcosis, summarizing the current knowledge about geographical distribution, molecular epidemiology, and transmission dynamics of Echinococcus granulosus sensu lato and Echinococcus multilocularis in this region. Additionally, we aimed to understand disease burden and risk factors as basic requirements for establishing a surveillance system and planning prevention and control programs. A considerable body of information is available on different aspects of echinococcosis in this region; however, several information and research gaps need to be filled before planning control programs. None of the countries in the region have an elaborate echinococcosis control program. Effective control programs require multi/intersectoral coordination within a One Health approach with a long-term political and administrative commitment and enhanced international collaboration among the three countries.

Demographics of Cystic Echinococcosis Patients Treated Surgically in Lahore, Pakistan: A Single Centre Study from 2007 - 2018

Cystic echinococcosis (CE) is a zoonotic disease caused by the larval stage of Echinococcus granulosus tapeworms. These parasites have a worldwide geographic distribution and pose a serious threat to livestock industry as well as human health in the endemic areas. CE is widely distributed in Pakistan. However, very few reports are available related to the regional transmission of E. granulosus. A retrospective analysis was conducted of surgically confirmed CE patients who were treated at Shoukat Khanum Memorial Cancer Hospital and Research Centre in Lahore, Punjab Province, Pakistan from 2007 – 2018. In total, 536 CE patients were evaluated during the study period. Cases originated from the provinces of Khyber Pakhtunkhwa (n=336), Punjab (n=147), Baluchistan (n=18), Sindh (n=3), Islamabad (n=2), Gilgit Baltistan (n=1), and Azad Jammu and Kashmir (n=1). An additional 28 cases were from Afghanistan. The highest number of CE cases was reported in 2013 (n=90). Females made up a larger proportion of cases (n=310; 57.8 %) than males (n=226; 42.2 %). Most patients were members of the Pashtun (n=197; 36.7 %), Hindku (n=142; 26.5 %), and Punjabi (n=118; 22.0 %) ethnic groups. The largest number of cysts was obtained from the liver (137/536; 25.6 %). This study showed that CE is likely present throughout Pakistan. In order to control the disease, a comprehensive control program and regional surveillance are needed.

Investigation of Echinococcus multilocularis in foxes and dogs in Pakistan by detection of copro-DNA

Alveolar echinococcosis (AE) is a zoonosis caused by Echinococcus multilocularis, a heteroxenous parasite belonging to Cestoda class. AE is currently considered an important public health issue, but epidemiological and notably molecular data from several endemic countries, including Pakistan, are sparse. Here we report the first detection of Echinococcus multilocularis in wildlife from Pakistan after real-time PCR and sequencing confirmation in the faecal samples of three foxes from northern Kaghan and Siran regions. The occurrence is estimated at 4.4% (95% CI 0.9-12.4). In order to go further in the epidemiological investigations on E. multilocularis and due to the potential presence of other Echinococcus species, we suggest the need for further epidemiological surveys targeting E. multilocularis and E. granulosus sensu lato isolates from humans and intermediate hosts as well as definitive hosts from wildlife in Pakistan.

First report of Echinococcus canadensis (G6/G7) by sequence analysis from the Khyber Pakhtunkhwa province of Pakistan

Cystic echinococcosis (CE) is a zoonotic parasitic disease that can result in human and animal health problems globally. Although the disease is known to be endemic in Asia and the Middle East, there are few epidemiological studies on CE in Pakistan. The purpose of the present study was to identify the Echinococcus granulosus sensu lato species and genotypes contributing to human CE cases in the Khyber Pakhtunkhwa (KPK) province of Pakistan. A total of fifty-six formalin fixed paraffin embedded (FFPE) CE cyst samples of human origin were collected from the Pathology Department, Rehman Medical Institute (RMI), KPK for the years 2012-2017. Cyst samples came from the liver (26/56; 46.4%), lungs (3/56; 5.3%), spleen (3/56; 5.3%), pelvis (1/56; 1.8%), breast (1/56; 1.8%), and thigh (1/56; 1.8%). The organ location for 21 of the cysts was not recorded. World Health Organization-Informal Working Group on Echinococcosis (WHO-IWGE) ultrasound-based cyst staging was available for 17 of the 26 (65.4%) hepatic cysts. Five of these cysts (29.4%) were CE3 (transitional), nine (52.9%) were CE4 (inactive), and three (17.6%) were CE5 (inactive). Most of the cysts were obtained from CE patients that were ethnically Afghan Pashtuns (44/56; 78.6%), while 12.5% (7/56) were from patients that were Pakistani Pashtuns. The majority (41/56; 73.2%) of patients reported having close interactions with dogs. Using 12SrRNA primers, 33 cyst samples were identified as being caused by E. granulosus sensu stricto (s.s.). Mitochondrially encoded cytochrome C oxidase 1 (mt-CO1) was evaluated for the remaining 23 samples. PCR product was obtained from six of these 23 samples. Of these six samples, one was identified as Echinococcus canadensis (G6/7). Haplotype analysis showed high haplotype and low nucleotide diversity for the mt-CO1 gene. There were 26 polymorphic sites for the mt-CO1 sequence, of which 65.3% (17/26) were parsimony informative. The E. canadensis mt-CO1 haplotype network consisted of 11 haplotypes, with a main central haplotype. In conclusion, it appears that E. granulosus s.s. and E. canadensis (G6/7) are circulating in the northwestern region of Pakistan. Further molecular epidemiological studies are needed to explore the local genetic diversity of the parasite.

Cystic echinococcosis in the Eastern Mediterranean region: Neglected and prevailing!

Cystic echinococcosis (CE) is distributed worldwide, extending from China to the Middle East and from Mediterranean countries to the sub-Saharan Africa and South America. According to WHO, one million people around the world are suffering from CE with an estimated burden of 183,573 DALYs. The annual monetary burden of the disease due to treatment costs and CE-related livestock losses has been estimated at US$ 3 billion. CE is endemic in all countries within the WHO Eastern Mediterranean Regional Office (EMRO). The region, which includes most of the Middle East and North Africa, is one of the most ancient foci of the domestic cycle of CE and is recognized as one of the major hotspots of CE. There are 22 countries in the EMRO, where about 688 million people are living at risk of CE. In many EMRO countries, little is known about CE epidemiology and transmission. WHO included echinococcosis in a list of 17 neglected tropical diseases (NTDs) and 12 neglected zoonotic diseases (NZDs). Accordingly, different regional offices of WHO organized several initiatives for CE control and prevention. WHO’s Western Pacific regional office considered echinococcosis as one of the region’s major health topics, and several preventive measures have been implemented in the American region with the support of Pan American Health Organization (PAHO) in Argentina, Peru, Uruguay, and Chile. Although CE is endemic in all 22 EMRO countries, surprisingly, CE is absent from the health topics list of diseases and conditions in this region. Therefore, CE clearly requires further attention in the WHO EMRO agenda, and the need for elaboration of specific measures for CE control is becoming apparent in EMRO countries, where substantial collaborations among the member states and WHO EMRO is of paramount importance. Major topics of collaborative activities include training programs and health communication on different aspects of CE control, analysis of CE burden, national and international surveillance and disease registry systems, technical support to promote epidemiological studies for collecting baseline data, cost–benefit analysis of control interventions, and intersectoral cooperation among the agriculture, veterinary, medical, and health sectors.

Surgically confirmed cases of cystic echinococcosis from Baluchistan Province, Pakistan for the years 2011-2018

INTRODUCTION

Cystic echinococcosis (CE) is a parasitic zoonotic disease caused by the larval stage of Echinococcus granulosus tapeworms. It has a worldwide geographic distribution and can threaten the livestock industry and human health in endemic areas, including Pakistan. CE prevalence is high in Pakistan due to lack of local knowledge about disease transmission and a lack of control measures. The Pakistan province of Baluchistan shares a border with Iran and Afghanistan and is largely agricultural. However, little is known about E. granulosus transmission in this region.

METHODS

Information on surgically confirmed cases of CE in Baluchistan Province was obtained through evaluation of paraffin fixed cyst samples and patient records obtained from three local hospitals for the years 2011-2018.

RESULTS

A total of 22 paraffin fixed samples were collected during the study period. The majority of cysts were obtained from the liver (9/22; 40.9%), with anatomical location not available for two of the cysts. Demographic information was available for 18 cases. Females made up 61.1% (11/18) of the cases. The largest numbers of cases were found in the 31-40 years age group (5/18; 22.7%).

DISCUSSION

This study shows that Echinococcus spp. parasites are circulating in the study area. In order to control the disease, a comprehensive regional surveillance and control program is needed.

Molecular characterization of human Echinococcus isolates and the first report of E. canadensis (G6/G7) and E. multilocularis from the Punjab Province of Pakistan using sequence analysis

BACKGROUND

Echinococcosis is a zoonotic parasitic disease causing serious health problems in both humans and animals in different endemic regions across the world. There are two different forms of human echinococcosis: Cystic Echinococcosis (CE) and Alveolar Echinococcosis (AE). CE is caused by the larval stage of Echinococcus granulosus sensu lato and AE by the larval stage of Echinococcus multilocularis. Geographically, CE is universally distributed, while AE is prevalent in the northern hemisphere. Although the disease is endemic in neighboring countries (China, Iran and India) of Pakistan, there are limited reports from that country. Besides, there are no comprehensive data on the genotyping of Echinococcus species in humans based on sequence analysis. This study aimed to detect the presence of human CE and to identify Echinococcus spp. in human isolates through genetic characterization of hydatid cysts in the Punjab Province of Pakistan.

METHODS

Genetic analysis was performed on 38 human hydatid cyst samples collected from patients with echinococcosis using mitochondrial cytochrome c oxidase subunit 1 (cox1), cytochrome b (cytb) and NADH subunit 1 (nad1). Patient data including age, epidemiological history, sex, and location were obtained from hospital records.

RESULTS

According to the sequence analysis we detected E. granulosus sensu stricto (n = 35), E. canadensis (G6/G7) (n = 2), and E. multilocularis (n = 1). Thus, the majority of the patients (92.1%, 35/38) were infected with E. granulosus s.s. This is the first molecular confirmation of E. canadensis (G6/G7) and E. multilocularis in human subjects from Pakistan.

CONCLUSIONS

These findings suggested that E. granulosus s.s. is the dominant species in humans in Pakistan. In addition, E. canadensis (G6/G7) and E. multilocularis are circulating in the country. Further studies are required to explore the genetic diversity in both humans and livestock.

Retrospective Study of Cystic Echinococcosis (CE) Based on Hospital Record from Five Major Metropolitan Cities of Pakistan

BACKGROUND

Human cystic echinococcosis (CE) is an important zoonotic parasitic disease. It is one of the NTDs having strong roots in Pakistan. There are limited studies on the prevalence of CE in Pakistan.

METHOD

A retrospective study was conducted to determine the geographical distribution of human CE in Punjab (Lahore, Multan, and Faisalabad) and Sindh (Karachi and Hyderabad) provinces of Pakistan. Clinical records of infected patients from nine major hospitals were retrieved from 2008 to 2018.

RESULTS

A total of 188 surgically confirmed cases were included from selected hospitals during the study period, which showed the annual frequency of 18.8 cases/year. The number of reported cases was higher in Sindh province (67.55%) compared to Punjab (32.45%). Total number of CE cases/city was higher in Karachi (47.34%) compared to Hyderabad city (20.21%), while in Punjab province, this frequency was higher in Lahore (25%) followed by Multan (5.32%) and Faisalabad (2.13%). Out of total 188 patients, 73 (38.83%) were males and 115 (61.7%) were females. In surveyed hospitals, high burden of infection was reported in young adults (21-30 years; 29.79%) followed by 21.81% and 17.02% in 31-40 and 41-50 age groups, respectively. Data retrieved from the hospital record of diagnosed cases of CE showed liver (36.17%, n = 68) as the most affected organ followed by lungs (26.06%, n = 49). In this survey, some unusual sites of cyst formation were also observed.

CONCLUSION

Current study is a step forward towards filling the gap of knowledge for prevalence and regional distribution of hydatidosis in Pakistan reporting the CE cases in humans for the first time in Multan and Faisalabad.