Why more research needs to be done on echinococcosis in Pakistan

ELISA based seroprevalence and risk factors for three zoonotic parasites (Toxoplasma gondii, Echinococcus granulosus and Trichinella spiralis) in humans in Khyber Pakhtunkhwa, Pakistan

Zoonotic parasitic infections can affect both animal and human health, while also having food safety and economic implications. These pathogens can also pose occupational risks for certain groups, including veterinary professionals, animal handlers, and butchers. This study was conducted in the district of Swabi located in the Khyber Pakhtunkhwa Province of northwestern Pakistan. Serum samples from 187 males 15 years of age and older representing four different exposure groups were tested for the presence of specific antibodies to Toxoplasma gondii, Echinococcus granulosus, and Trichinella spiralis antigen using an enzyme-linked immunosorbent assay (ELISA). The exposure groups were no current animal ownership, livestock ownership, dogs and/or cats in the household, and the occupation groups butchers, and veterinarians or para-veterinarians. Seropositivity for each parasite was evaluated by subgroup. Fisher's exact test was used to evaluate possible associations between seropositivity, and potential categorical variables obtained through administration of a questionnaire. Anti-Toxoplasma antibodies were detected in 55 (29.4 %) of the 187 samples. In addition, 26.8 % (47/175) of individuals with available samples had antibodies to E. granulosus, and a single (0.5 %; 1/187) individual had antibodies to T. spiralis. One individual was seropositive for all three parasites and 9 individuals were seropositive for two parasites. The only significant factor was that Echinococcus seropositivity was associated with age group (p = 0.023) among butchers. The knowledge obtained through this study will be informative for the implementation of prevention and control strategies against these parasites at a local scale.

China's prevention and control experience of echinococcosis: A 19-year retrospective

Echinococcosis poses a significant threat to public health. The Chinese government has implemented prevention and control measures to mitigate the impact of the disease. By analyzing data from the Chinese Center for Disease Control and Prevention and the State Council of the People's Republic of China, we found that implementation of these measures has reduced the infection rate by nearly 50% between 2004 to 2022 (from 0.3975 to 0.1944 per 100,000 person-years). Nonetheless, some regions still bear a significant disease burden, and lack of detailed information limites further evaluation of the effects on both alveolar and cystic echinococcosis. Our analysis supports the continuing implementation of these measures and suggests that enhanced wildlife management, case-based strategies, and surveillance systems will facilitate disease control.

Genetic diversity and haplotypes of Echinococcus granulosus isolated from cattle and buffaloes and first report of E. ortleppi (G5) in buffaloes in Pakistan based on mitochondrial cytochrome c oxidase subunit-1 gene (mt-CO1) markers

Cystic echinococcosis (CE) is a parasitic disease that is caused by larval stage of Echinococcus granulosus tapeworm, one of the most important and neglected zoonotic disease. Although the echinococcosis is endemic in the neighboring countries, information regarding circulating genotypes of E. granulosus sensu lato is scarce in Pakistan. Therefore, the main purpose of this report was to contribute in molecular epidemiology and to find genetic variation and haplotypes of E. granulosus s.l. in cattle and buffalo isolates. To identify species circulating in country, parasite samples were collected from different slaughterhouses and butcher shops of two major cities, Rawalpindi and Peshawar located in Punjab and Khyber Pakhtunkhwa (KP) provinces, Pakistan, respectively. A total of 100 CE cyst samples were investigated from buffalo (n = 61), and cattle (n = 39) hosts. After genomic DNA extraction from individual cyst materials, mt-CO1 (875 bp) gene was amplified by PCR. After that, PCR products were electrophoresed on the agarose gel then purified and sequenced using forward primer. The sequences were trimmed (779 bp), aligned and matched with NCBI published sequences. E. granulosus s.s. (G1, G3) (71.4%; n = 20/28) was confirmed as the dominant species in buffalo and cattle. E. ortleppi (G5) (28.6%; n = 8/28) was recorded for the first time in both buffalo and cattle isolates from Rawalpindi. E. granulosus s.l. haplotype network showed single predominant haplotype, which comprised 40% of population. Tajima's D and Fu's Fs were negative and significant for E. ortleppi (G5), suggesting population expansion in Pakistan. Therefore, more studies using isolates of E. granulosus s.l. from various locations and intermediate hosts across Pakistan will add new data on molecular epidemiology and genotyping for effective control strategies of CE in Pakistan.

Revealing novel cytb and nad5 genes-based population diversity and benzimidazole resistance in Echinococcus granulosus of bovine origin

Cystic echinococcosis (CE) is a neglected zoonotic disease caused by Echinococcus granulosus (sensu stricto). The parasite affects a wide range of livestock and wild animals. In this study, the population diversity of the Echinococcus species was investigated based on mitochondrial cytochrome b (cytb) and NADH dehydrogenase subunit 5 (nad5) genes. In addition to this, β-tubulin gene isoforms of Echinococcus granulosus were amplified to determine the resistance against benzimidazoles. For this purpose, 40 cyst samples from cattle (n = 20) and buffaloes (n = 20) were collected from the main abattoir of Sialkot. DNA extraction was performed using Qiagen Blood and Tissue Kits. Amplification was performed through PCR. Each amplicon was confirmed by GelRed™ stained agarose gel (2%). Samples were sequenced in a DNA analyzer and viewed for any misread nucleotide by using MEGA (v.11). Corrections in nucleotide sequence and multiple sequence alignment were made through the same software. NCBI-BLAST was used for sample specific sequences to identify them as belonging to a particular species. Diversity indices were estimated using DnaSP (v.6) while phylogenetic analysis was inferred using the Bayesian method using MrBayes (v.1.1). β-tubulin gene isoforms sequence analysis was performed to find out the candidate gene causing benzimidazole resistance. All 40 isolates were found positive for E. granulosus. BLAST-based searches of sequences of each isolate for each gene (nad5 and cytb) confirmed their maximum similarity with the G1 genotype. Overall, high haplotype diversity (Hd nad5 = 1.00; Hd cytb = 0.833) and low nucleotide diversity (π nad5 = 0.00560; π = cytb = 0.00763) was identified based on diversity indices. For both the genes, non-significant values of Tajima's D (nad5 = -0.81734; cytb = -0.80861) and Fu's Fs (nad5 = -1.012; cytb = 0.731) indicate recent population expansion. Bayesian phylogeny-based results of nad5 and cytb sequences confirmed their genotypic status as distinct from other Echinococcus species. This study shed light on the status of benzimidazole resistance in Echinococcus granulosus for the very first time from Pakistan. The findings of this study will significantly add in the information available on genetic diversity of Echinoccous granulosus based on cytb and nad5 genes sequences.

IEg67 kDa Bovine Hydatid Cyst Antigen: A Candidate for Developing Sero-Diagnostic Assays for Cystic Echinococcosis, a Disease of One Health Importance

Cystic echinococcosis (hydatidosis) is a world-wide zoonotic disease of mainly humans, livestock and dogs, caused by Echinococcus granulosus. The disease can negatively impact food production and animal welfare and causes socio-economic hardship. Here, we aimed to identify the local bovine hydatid cyst fluid (BHCF) antigen for developing a sero-diagnostic assay to be used for the pre-slaughter screening of food animals. In total, 264 bovines approved for slaughter in Pakistan were subjected to serum collection and post-mortem screening for hydatid cysts. These cysts were assessed microscopically to assess fertility and viability, and by PCR for molecular confirmation of species. A BHCF antigen was identified from positive sera via SDS-PAGE, confirmed by Western blot, and quantified via a bicinchoninic acid (BCA) assay. The quantified crude BHCF antigen (iEg67 kDa) was then used in ELISA screening to test all sera collected from known positive and negative animals based on hydatid cyst presence/absence. Of the 264 bovines examined, 38 (14.4%) showed hydatid cysts during post-mortem examination. All of these individuals, plus an additional 14 (total: 52; 19.6%) tested positive based on less time-consuming ELISA examination. Based on ELISA, occurrence in females (18.8%) was significantly higher than in males (9.2%) and was higher in cattle (19.5%) compared to buffalo (9.5%). The infection rate increased with age in both host species: cumulatively, 3.6% in animals aged 2-3 years, 14.6% in 4-5-year-olds and 25.6% in 6-7-year-olds. The occurrence of cysts in cattle was significantly higher in the lungs (14.1%) compared to their livers (5.5%), whereas the opposite was true in buffalo (6.6% livers, 2.9% lungs). For both host species, most cysts in the lungs were fertile (65%), while the majority in the liver were sterile (71.4%). We conclude that the identified iEg67 kDa antigen is a strong candidate for the development of a sero-diagnostic screening assay for the pre-slaughter diagnosis of hydatidosis.

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.

Assessment of risk, landscape epidemiology and management strategies to combat alveolar echinococcosis in the rural communities of Hunza, Pakistan

BACKGROUND

Human alveolar echinococcosis (AE) is a neglected zoonotic disease. Prevalence of AE in humans is reported in Pakistan as a result of poor economic and sanitary conditions, close proximity to wildlife and limited knowledge of AE. Studies on the prevalence and transmission of AE have been limited, especially for rural Pakistan. The study objectives were to identify knowledge, attitudes and practices relating to AE, to determine awareness of the disease, and to identify knowledge about possible risk factors of infections involving the landscape epidemiological attributes of rural villages in Hunza, one of the districts of Gilgit-Baltistan, a region of Pakistan that borders China.

METHODS

A community-based cross-sectional study was conducted among the general population of Hunza to establish the level of awareness, knowledge, attitudes, practices, landscape epidemiology, and disease management and control relating to AE in rural areas of Hunza. Data were collected by questionnaire.

RESULTS

A total of 387 questionnaires was received. Statistical analysis showed that the population's knowledge about the disease was poor. The attitudes and practices of the participants indicated that their risk of infection was low. Knowledge of landscape epidemiology of the disease was poor but knowledge about AE disease management was good. The attitudes of residents toward disease treatment and control strategies were positive, although the overall knowledge of participants about prevention of infection was poor.

CONCLUSION

Knowledge of AE is poor among the residents of Hunza, Pakistan. Our study demands continued and strengthened awareness of the changes to lifestyle and practices associated with AE, not only in the study locality but throughout other areas of Pakistan.

One Health Paradigm to Confront Zoonotic Health Threats: A Pakistan Prospective

The emergence and re-emergence of zoonotic diseases significantly impact human health, particularly those who live in impoverished areas and have close contact with domestic or wild animals. Nearly 75% of zoonotic diseases are transmitted directly from animals to humans or indirectly via vector/agent interactions between animals and humans. Growing populations, globalization, urbanization, and the interaction of the environment with humans and livestock all play roles in the emergence and spread of zoonotic diseases. "One Health" is a multidisciplinary concept aimed at improving human, animal, and environmental health, but this concept is not widely accepted in developing countries. In Pakistan, environmental, human, and animal health are severely affected due to a lack of sufficient resources. This review article provides an overview of the most common zoonotic diseases found in Pakistan and emphasizes the importance of the "One Health" concept in managing these diseases. Given the current situation, interdisciplinary research efforts are required to implement and sustain effective and long-term control measures in animal, human, and environmental health surveillance and accurate diagnostic methods.

A Retrospective Cohort Study on Human Cystic Echinococcosis in Khyber Pakhtunkhwa Province (Pakistan) Based on 16 Years of Hospital Discharge Records

Human cystic echinococcosis (CE) is a worldwide-distributed parasitic zoonotic disease, which represents a threat for both human and animals. The current study aimed at estimating the prevalence of human CE in Khyber Pakhtunkhwa (KPK) province of Pakistan. Clinical records from four major hospitals in this region were reviewed for CE human cases during the period of 2006-2021. Out of 251 (0.00071%) CE patients identified during the considered period, 142 (56.6%) were females, and 109 (43.4%) were males. The highest number of CE cases was recorded in the 21-30 (27.9%) age group, followed by 31-40 (23.1%) and 41-50 (16.3%). Most of the CE patients in KPK province were members of the Afghani ethnic group (17.1%); secondarily, they were Pakistani (6.4%), while for 76.5% ethnicity data were not available. The liver (41%) and the lungs (4.8%) were the most infected organs identified among CE patients in KPK province. The present study identified CE as a significant public health problem in KPK province, and the current findings demonstrated a constant endemicity of CE during the last 15 years. Further filed studies on the active search of CE carriers by means of ultrasound population-based surveys are needed to fill knowledge gaps on clinical and molecular epidemiology of human CE in Pakistan.

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.

Prevalence and Molecular Characterization of Cystic Echinococcosis in Livestock Population of the Malakand Division, Khyber Pakhtunkhwa, Pakistan

Cystic echinococcosis (CE) is a neglected zoonotic disease prevalent in Pakistan, but the genetic diversity of the cestode is largely unexplored in the country. This study investigated the molecular epidemiology of CE infecting the livestock population of the Malakand division, Khyber Pakhtunkhwa, Pakistan. A total of 1,200 livestock, including buffaloes, cattle, goats, and sheep, were examined for echinococcosis from November 2017-2018 at different slaughterhouses in the Malakand division. Hydatid cysts were collected from different organs, and hydatid cyst fluid (HCF) was examined microscopically and used for DNA extraction. The LSU (rrnl) and NAD1 genes were amplified and sequenced. The overall prevalence of CE was 17% (204/1,200), including cows (21.7%), buffaloes (17.4%), goats (10%), and sheep (9.6%). The infection was relatively more prevalent among males (17%) than females (16.9%) and animals of older age (>5 years) (p = 0.710). Liver (63.2%) and lungs (25%) were more affected as compared to kidneys (6.8%) and heart (4.9%). HCF analysis indicated that 52.0% of the cysts were sterile and (48.0%) were fertile. Sequencing and phylogenetic analyses confirmed 80.0% of the isolates as Echinococcus granulosus sensu stricto (G1-G3) in all animal species, while Echinococcus equinus (G4) and Echinococcus ortleppi (G5) were present in buffaloes. The present study concluded that CE is prevalent in the livestock population of Malakand. Besides E. granulosus s. s. (G1-G3), E. ortleppi genotype (G5) and E. equinus (G4) in livestock were also reported.

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.

Community Based Assessment of Behavior and Awareness of Risk Factors of Cystic Echinococcosis in Major Cities of Pakistan: A One Health Perspective

Background: The parasitic disease, cystic echinococcosis (CE), is a serious health problem in Pakistan. Risk of disease transmission is increased by economic and political instability, poor living conditions, and limited awareness of hygienic practices. The current study aimed to investigate the community perception and awareness regarding the risk factors of CE in Pakistan, from a One Health perspective. Methods: We conducted a community-based survey involving 454 participants in the major cities of Pakistan. Quantitative data based on knowledge, attitude, and practices (KAP), the One Health concept, risk factors, and community perception of CE among the general population of the major cities of Pakistan were collected. The questions included those related to knowledge, attitude, practices, One Health concept, risk factors, and community perception. The Chi-squared test was applied to determine the associations regarding KAPs across socio-demographic parameters. Results: KAPs had no significant associations with sociodemographic aspects such as age, sex, religion, ethnicity, education, marital status, occupation, or financial status of the participants. The findings indicated a lack of awareness about CE among the participants. Respondents were unaware of the risk factors and the One Health concept of CE. However, the community attitude and perception were positive toward the control of CE. Conclusion: Illiteracy, deficient sanitation systems and lack of awareness are the contributing factors to CE in Pakistan. It is necessary to make the community aware regarding CE and its importance. Increasing this awareness represents an important step toward the eradication and control of CE.

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.

Occurrence of Massively Enlarged Multiple Hydatid Cysts in the Lung and Liver of a Pediatric Patient in Pakistan

The article's abstract is not available.

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.

Management Outcome in Simple and Complex Hydatid Cysts of Lung

Introduction: Hydatid cyst (HC) of lung is a frequently encountered entity in Pakistan. The clinical and radiological manifestations of HC in lung depend on the integrity of the cyst. Patients may remain asymptomatic for years in cases of simple HC or may present with a wide variety of complications when it ruptures. The aim of this study was to compare management outcomes in simple and complex HCs.

Methods: This prospective, observational study was conducted from February 2019 until May 2020. Patients were divided into two groups: simple HC (Group A) and complex HC (Group B). Preoperative complications, surgical procedures, postoperative complications, duration of hospital stay, duration of chest tube placement and need for readmission were noted and compared between the two groups. All data was processed through the Statistical Package for the Social Sciences (SPSS) Statistics version 22 (IBM Corp., Armonk, NY).

Results: Sixty-two patients were included out of which Group A had 28 (45.2%) patients and Group B had 34 (54.8%) patients. There were 39 (62.9%) males and 23 (37.1%) females. The mean age was 31.11 ± 11.02 years. Preoperative complications in Group B included empyema seen in 10 (28.5%) patients, rupture of cyst into bronchus in 8 (23.5%), biliopleural fistula in 4 (11.7%), hydropneumothorax in 2 (5.8%), bronchopleural fistula in 1 (2.9%), airway compromise in 1 (2.9%) and pneumonia in 1 (2.9%) patient. Group B required longer days of chest tube placement, longer intensive care unit stay and longer hospital stay (p<0.001). The frequency of postoperative intervention was more in group B (p<0.05), therefore requiring readmission.

Conclusion: Surgery has favorable outcomes in the management of HC of lung. Complications associated with complex HC not only requires preoperative intervention like chest tubes but can also lead to life-threatening complications. There is also a frequent need for additional procedures during surgery in cases with complex HC along with greater risk of postoperative complications. All these are associated with prolonged hospital stay, readmissions and greater morbidity. Hence, early diagnosis and referral is needed to avoid these preventable complications associated with cyst rupture.

Cystic Echinococcosis in Pakistan: A Review of Reported Cases, Diagnosis, and Management

Cystic echinococcosis (CE) is a zoonotic disease that occurs in humans and ungulates due to infection with the larval stage of the taeniid cestode Echinococcus granulosus sensu lato. It has been estimated that approximately one million people are infected annually, resulting in US$3 billion in human and livestock-associated direct and indirect losses per year. CE is a serious public health concern in many parts of the world, including Pakistan. This review discusses the causative agent as well as the epidemiology, diagnosis, and treatment of CE 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.

Echinococcus granulosus (sensu stricto) (G1, G3) and E. ortleppi (G5) in Pakistan: phylogeny, genetic diversity and population structural analysis based on mitochondrial DNA

Background

Cystic echinococcosis (CE) is a serious tapeworm infection caused by Echinococcus granulosus (sensu lato) which infects a wide range of animals and humans worldwide. Despite the millions of livestock heads reared in Pakistan, only a few reports on CE prevalence and even fewer on the genetic diversity are available for the country. Meanwhile, the available reports on the genetic diversity are predominantly based on short sequences of the cox1 gene.

Methods

To close this knowledge gap, this study was designed to investigate the genetic diversity and population structure of Echinococcus spp. in Pakistan using the complete mitochondrial cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes.

Results

Based on BLAST searches of the generated cox1 and nad1 gene sequences from a total of 60 hydatid cysts collected from cattle (n = 40) and buffalo (n = 20), 52 isolates were identified as E. granulosus (s.s.) (G1, G3) and 8 as E. ortleppi (G5). The detection of the G5 genotype represents the first in Pakistan. The phylogeny inferred by the Bayesian method using nucleotide sequences of cox1-nad1 further confirmed their identity. The diversity indices indicated a high haplotype diversity and a low nucleotide diversity. The negative values of Tajima’s D and Fu’s Fs test demonstrated deviation from neutrality suggesting a recent population expansion.

Conclusions

To the best of our knowledge, this report described the genetic variation of E. granulosus population for the first time in Pakistan using the complete cox1 and nad1 mitochondrial genes and confirms E. ortleppi as one of the causative agents of CE among livestock in Pakistan. While this report will contribute to baseline information for CE control, more studies considering species diversity and distribution in different hosts across unstudied regions of Pakistan are highly needed.

Human cystic echinococcosis in southwest Iran: a 15-year retrospective epidemiological study of hospitalized cases

Background

Cystic echinococcosis (CE) is considered as a neglected disease with significant mortality and morbidity in most of the developing countries. The current study aimed to retrospectively assess the demographic and epidemiologic features of human CE surgical cases in a 15-year period in Fars province, southwestern Iran.

Methods

A 15-year (2004–2018) retrospective study was conducted to find out the epidemiological and clinical picture of CE in patients who undergone surgeries for CE in two main hospitals in Fars Province, southwestern Iran. Hospital records were reviewed, and data were retrieved from each CE patient’s record.

Results

A total of 501 CE surgical cases were recorded during a 15-year period, corresponding to an average annual incidence of 33.4 and a surgical incidence rate of 0.74/100,000 population. Of these, 242 (48.6%) were male, and 256 (52.4%) were female. Patients’ age ranged from 2 to 96 years, with a mean age of 34.92 (± 19.87) years. A significantly higher rate of CE cases was noted in subject’s ≥ 50 years of age. The highest frequency of cases (62:12.5%) was recorded in the year 2017. The most commonly involved organs were liver (339 cases; 57.8%) and lung (279 cases; 47.6%). Concurrent involvement of two organs was seen in 58 (9.9%) cases of both lung and liver, 10 (1.6%) cases of lung and other locations (but not liver), and 23 (3.9%) cases of liver and other locations (but not lung). Reoperation was noted in 67 (13.4%) of the cases. The size of the lung hydatid cyst varied, ranging between 2 and 24 cm (mean = 7.33, SD = 3.737). The size of liver hydatid cysts ranged from 1 to 26 cm (mean 9.04, SD = 4.275).

Conclusion

The findings of the current study demonstrated a nearly constant prevalence of CE during the last 15 years in southern Iran. Further studies are needed to find out the reasons behind the recurrence of the disease, which is substantial, in surgically-treated patients.

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.

Spread of Cystic Echinococcosis in Pakistan Due to Stray Dogs and Livestock Slaughtering Habits: Research Priorities and Public Health Importance

Background: Cystic echinococcosis (CE) is a global zoonotic parasitic disease caused by the larval stage of Echinococcus granulosus and it has been reported from both livestock and humans in Pakistan. The definitive host of E. granulosus is the dog, and the large number of stray dogs in Pakistan contributes to the spread of CE. However, there is little information between stray dogs and CE relation in the country. Methods: During the study, total 123 butcher's shops and abattoirs were included for collection of data relating to the hydatid cyst prevalence in slaughtered animals (sheep, goat, cattle, and buffaloes). The number of animals slaughtered in each butcher's shop during sampling period was also recorded, and the association of the shop environment with dogs was inspected. Results: Data was collected for CE from 123 butcher's shops in Rawalpindi and Islamabad, Pakistan. The slaughtering rate the in the butcher's shops was 2-10 animals/day including sheep/goat/cattle and buffaloes. The overall prevalence of CE in all examined animals was 2.77%. In buffaloes the higher prevalence was recorded as compared to other hosts. The findings showed that lung and liver were most affected organs and majority (59%) of the cysts were fertile in infected animals. The presence of a large number of stray dogs were an important factor in the spread of CE. They were rarely vaccinated, have easy access to infected offal at slaughtering site and had insufficient or inappropriate anthelmintic treatment. Conclusions: The most pressing need is to raise public awareness of this huge problem by considering CE a major ailment and promoting the collection and mapping of epidemiological data. Efficient CE control is required, especially treating dogs with antiparasitic drugs, for which government support and affiliation with the veterinary sector is essential.

Cystic echinococcosis: a 10-year experience from a middle-income country

Cystic echinococcosis (CE), or hydatid disease, is a neglected tropical disease (NTD) afflicting one million people globally. This study aims to elucidate the presentation, treatment and outcomes of the disease in Pakistan. A review of charts of 225 patients (median age = 42.3 years) with CE admitted at Aga Khan Hospital, Karachi during 2007-2017, was carried out. Abdominal pain was present in 34.7% followed by fever in 26.2%. There were 142 (63.1%) cases of hepatic cysts and 55 (24.4%) of pulmonary hydatid cysts. Combined surgical and medical therapy was given to 130 (57.8%) patients. Surgery only was performed in 23 (10.2%) patients, medical therapy only was given to 35 (15.6%) patients, and puncture, aspiration, injection and reaspiration (PAIR) with medical therapy was given to 15 (6.7%) patients. Recurrence occurred in 14 (6.2%) patients and mortality in 7 (3.1%) patients. Owing to its non-specific presentation, a high index of suspicion is required to diagnose and treat CE in a timely manner.

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.

The Maverick Disease: Cystic Echinococcosis in Unusual Locations: A Ten Year Experience from an Endemic Region

Background Cystic echinococcosis (CE) is a neglected tropical disease which affects more than 1 million people globally, causing a loss of 1-3 million disability-adjusted life years (DALYs) and a financial burden of US$ 3 billion annually.The two most commonly involved organs are the liver and the lungs with involvement in 75% and 5 -15% of cases respectively. The rest of the body can be involved in up to 10% of cases. In this study, we aim to explore the presentation, treatment and outcomes of CE in unusual locations. Methods Retrospective review of charts of 225 patients of CE admitted at Aga Khan Hospital, Karachi from 2007-2017 was done. Demographic information, date of admission, clinical presentation, laboratory and radiological findings, histopathology reports (where applicable), treatment course and outcomes were noted. Results CE occurred in the liver in 146 (64.9%) patients, in the lungs in 55 (24.4%) patients and in unusual locations in 24 (10.7%) patients. Primary involvement of unusual locations was seen in 22 (91.7%) cases. Amongst the 24 patients with disease in unusual locations, 13 (54.2%) were males and 11 (45.8%) were females and the median age of these patients was 43 years. Fever and dyspnea were the most common presenting complains, occurring in 5 (20.8%) patients each followed by epigastric abdominal pain and weight loss occurring in 3(12.5%) patients each. Spleen was the most common unusual location for CE with four cases (16.7%) of splenic involvement occurring, followed by cardiac, spinal and mediastinal involvement occurring in three (12.5%) patients each. Other unusual locations included the abdominal cavity, bones, breast, kidney, seminal vesicle, brain, adrenal glands and the inguinal region. The treatment courses employed were a) medical, consisting of oral albendazole use(400 mg twice daily), b) surgical c) combined (medical plus surgical) therapy. Combined surgical and medical therapy, was the most common modality employed, with it being given to 14 (58.3%) patients. Surgery only was performed in 5 (20.8%) patients while medical therapy only to 3 (12.5%) patients. Resolution of the disease was seen in 19 (79.2%) patients on follow up imaging. Recurrence occurred in 4 (16.7%) and mortality in 1 patient. Two patients (8.3%) were lost to follow up. Conclusions CE can be challenging to diagnose especially when it occurs in unusual locations. CE must be included in the differential diagnosis of a cystic lesion in any organ of the body, especially in endemic areas, to ensure timely diagnosis and treatment, to prevent morbidity and mortality associated with chronicity of the disease.

A Retrospective Analysis on the Cystic Echinococcosis Cases Occured in Northeastern Punjab Province, Pakistan

A retrospective study was performed to report the case occurrence of cystic echinococcosis (CE) in three hospitals of north-eastern region in Punjab Province, Pakistan. We reviewed retrospectively the clinical records of patients in 4 hospitals which were diagnosed with CE during 2012-2017. A total of 198 cases, 82 (41.4%) male and 116 (58.6%) females were detected as CE. The most Highest incidence was revealed in.... 21-30 years-old group (24.2%) followed by 41-50 (22.7%), 31-40 (16.2%), 11-20 (13.6%), 51-60 (8.1%), below 10 (5.5%), over 71 (5.1%) and 61-70 year-old group (4.5%). CE was detected in various organs of infected individuals. However, most of CE cases were detected in the liver (47.4%) and lung (18.6%). The present study indicated that CE is more or less prevalent in surveyed areas and one of the most important public health problems in Punjab Province, Pakistan.

Knowledge, attitudes and practices related to cystic echinococcosis endemicity in Pakistan

BACKGROUND

Cystic echinococcosis (CE) is a human and animal health problem in many endemic areas worldwide. It is considered a neglected zoonotic disease caused by the larval form (hydatid cyst) of Echinococcus spp. tapeworm. There are limited studies on echinococcosis in Pakistan.

METHODS

A cross-sectional survey was conducted to find out recent knowledge, attitudes and practices on the occurrence of cystic echinococcosis in butchers and dog owners in both urban and rural areas of Rawalpindi/Islamabad regions, Pakistan. The quantitative data was collected in the form of questionnaires to investigate the knowledge and awareness of CE among community members and their routine practices that  were behind the factors involved in hydatid cyst infection. The practices and infrastructure of abattoirs/butcher shops and their role in transmission of cystic echinococcosis were also evaluated in the present study.

RESULTS

The participants involved in the study were dog owners and people who kept animals. A total of 400 people were interviewed and 289 questionnaires were received. The results showed that only 4.1% of people have heard about the disease, and 58.1% were closely associated with dogs. Sixty-three percent of dogs in study area were consuming uncooked organs (e.g. liver, lung, etc.) of slaughtered animals, while 100% of dogs at butcher shops were consuming uncooked organs. Home slaughtering was common in 20.06%. Among butchers, 32.3% had heard about zoonoses and 7.61% knew about CE. The statistical analysis showed that there was highly significant difference (P < 0.05) among most of the practices that were associated with the prevalence of CE.

CONCLUSIONS

It  was concluded from the present study that, the knowledge and awareness of CE among people of Rawalpindi/Islamabad were low. Because of dogs and poor knowledge of CE among community members and butchers, the transmission of echinococcosis is facilitated. Therefore, there is urgent need to strengthen awareness and health education among people, as well as proper practices related to the CE not only in the study area, but also in other areas of Pakistan.