Sami K. Abdel-Hafez

Genetic polymorphisms of Echinococcus granulosus sensu stricto in the Middle East

Echinococcus granulosus sensu stricto is a cosmopolitan parasite causing cystic echinococcosis in humans and livestock. Recent molecular phylogeographic studies suggested the rapid dispersal of the parasite by the anthropogenic movement of domestic animal hosts. In the present study, genetic polymorphism of E. granulosus s. s. in the Middle East, where the domestication started, was investigated to validate the dispersal history of the parasite. Thirty-five and 26 hydatid cysts were collected from Iran and Jordan, respectively, and mitochondrial cytochrome c oxidase subunit I (cox1) gene was sequenced. Chinese and Peruvian specimens were also analyzed for comparison. Haplotype network analysis demonstrated the existence of a common haplotype EG01 in all populations. Although EG01 and its one-step neighbors were the majority in all regions, most of the neighboring haplotypes were unique in each locality. Haplotype diversity was high but nucleotide diversity was low in Iran, Jordan and China. Both diversities were lowest and only a few haplotypes were found in Peru. Neutrality indices were significantly negative in Iran, Jordan and China, and positive but not significant in Peru. Pairwise fixation index was significant for all pairwise comparisons, indicating genetic differentiation among populations. These results suggest a evolutionary history of E. granulosus s. s. in which a genetic subgroup including EG01 was selected at the dawn of domestication, and then it was rapidly dispersed worldwide through the diffusion of stock raising. To approach the origin of the ancestral strain, extensive sampling is needed in many endemic regions. To evaluate the hypothetical evolutionary scenario, further study is needed to analyze specimens from diverse host species in wider regions.

Further studies on prevalence of hydatidosis in slaughtered animals from North Jordan

Examination of 471 sheep, 118 goats, 157 cattle and 56 camels slaughtered in abattoirs in North Jordan was carried out during March–May 1984. Drought conditions that prevailed during the preceding winter led to slaughtering old female sheep (≥4 years) due to scarcity of food, which allowed us to analyse the prevalence of hydatidosis in various age groups of sheep. An overall infection rate of 27.8, 1.7, 5.8 and 10.7 percent was found in sheep, goats, cattle and camels, respectively. The infection rate was as low as 1.5 percent in male and 1.9 percent in female sheep under 2 years of age. However, the rate of hydatid infection increased with age and reached as high as 63.7 percent in ewes 4 years of age and older. The percentage of animals with fertile cysts was also highest in sheep (68.7 percent of infected animals) and increased with age reaching 100 percent in ewes which were 10 years of age or older. Analysis of all cysts recovered from the livers and lungs of infected ewes from various age groups revealed a sharp increase in the mean total number of cysts in age groups over 8 years of age. The fertility rate of the cysts in the liver was significantly greater in ewes 6 years old or more (64.8–78.6 percent) than in younger age groups (8.7–46.2 percent). In the lung, the fertility rate increased progressively with age reaching as high as 97.9 percent in ewes 10 years old or more. These findings of high infection and fertility rates of hydatid disease in sheep, particularly of older age groups, prompt plans for further epidemiological studies and control programmes.

Serodiagnosis and seroepidemiology of human unilocular hydatidosis in Jordan

A total of 2182 serum samples from 38 patients with surgically confirmed unilocular hydatidosis, 19 clinically assessed patients, 15 patients with parasitic infections other than hydatidosis, 104 hospital outpatients, and 2006 normal Jordanians were serodiagnosed for the presence of IgG antibodies against hydatid fluid, circulating immune complexes (CIC), and/or hydatid circulating antigen (CA). Anti-hydatid IgG antibodies were detected in the sera of 77.4% of patients with hydatid discase and persiste for very long periods postsurgery. As many as 54.1% of patients with hydatidosis had positive levels of CIC, and 16.1% had circulating antigen in their sera. The search for circulating antigen and CIC decreased the number of false-negative hydatid cases from seven to three, and the combined sensitivity of the assays thus increased from 77.4% to 90.3%. Using the immunoblot technique, 16- and <14.4-kDaEchinococcus granulosus-specific bands were detected in sera from 54.1% and 61.5% of patients with hydatid disease who were tested before and after surgery, respectively. The seropositivity rate for anti-hydatid IgG antibodies was 2.4% for the general Jordanian population and 5.8% for hospital outpatients.

Prevalence of intestinal helminths of dogs and foxes from Jordan

Abstract Necropsy of 340 stray and semi-stray dogs (Canis familiaris) and nine red foxes (Vulpes vulpes) from Jordan revealed that 239 dogs (70.3%) and all foxes were infected with at least one intestinal helminth species. No trematodes were found in the intestine of these hosts. The overall infection rates with cestodes, nematodes and acanthocephalans in dogs were 66.8%, 4.4% and 2.9%, respectively. The following cestodes were identified: Echinococcus granulosus (9.4%), Taenia pisiformis (11.8%), T. hydatigena (7.4%), T. ovis (4.4%), T. multiceps (3.8%), T. taeniaeformis (2.9%), Dipylidium caninum (19.4%), Joyeuxiella (3.2%), Diplopylidium (2.4%), and Mesocestoides (0.9%). Other intestinal worms in dogs were Toxascaris (2.6%), Toxocara canis (1.2%), and Protospirura (0.6%) nematodes, and gigantorhynchiid acanthocephalans (2.9%). Intestinal helminths found in foxes included cestodes (D. caninum, Joyeuxiella, Diplopylidium, Mesocestoides), nematodes (Protospirura, Uncinaria stenocephala and Oxynema) and an acanthocephalan (Macracanthorhynchus). In both hosts, most helminths were recovered from the second intestinal segment of four equally divided segments.

Human cystic echinococcosis in the West Bank of Palestine: surgical incidence and seroepidemiological study

Abstract. The surgical incidence of cystic echinococcosis (CE) due to Echinococcus granulosus was investigated in hospitals of the West Bank, Palestinian Authority between January 1990 and December 1997. Serum samples from school-children in Yata town, which showed the highest surgical incidence, were tested for anti-hydatid antibodies. A total of 390 surgically confirmed cases were recorded throughout the 8-year period, with an overall mean annual surgical incidence (MASI) of 3.1 per 100,000. A high MASI of 4.9, 5.0 and 5.1 per 100,000 was found in Hebron, Jericho and Bethlehem Governorates, respectively. Yata town, Hebron governorate, showed the highest MASI, at 16.8 per 100,000. The highest incidence was found in age groups 11–20 and 21–30 years, at 27.4% and 21.5% of the total number of cases. While there was no significant gender difference in the number of cases in the age groups of 20 years or less, the male to female case ratio was 1:3.2–4.1 in the older age groups. The liver was the most common site of hydatid cysts in 69.9% of cases. Lung cysts were predominant in younger age groups (20 years or less). The seropositivity for CE in the school-children of Yata was 2.4% and 2.1% using enzyme-linked immunosorbent assay and the indirect haemagglutination test, respectively. CE is a significant endemic disease throughout the West Bank. The disease is acquired early in life and is more prevalent among females than males. Behaviour and life-style favour the spread of the disease.

Retrospective surgical incidence and case distribution of cystic echinococcosis in Jordan between 1994 and 2000.

A retrospective follow-up study on the surgical incidence of cystic echinococcosis (CE) was carried out in major governmental, military and private hospitals throughout Jordan between 1994 and 2000. A total of 472 cases were recorded over the 7-year period and an overall mean annual surgical incidence (MASI) of 2.3 per 100,000 inhabitants was estimated. The highest number of surgical cases was recorded in hospitals of the middle region of the country. The highest MASI (3.6 per 100,000) was found in the southern region while the lowest (1.4 per 100,000) was in the northern region of the country. Taking into consideration the population size and the origin of surgically confirmed cases of each region, a relative surgical index (RSI) was calculated at which the highest (RSI=3.4) was among cases originated from the southern region and the lowest (RSI=0.7) was among those originated from the middle region of Jordan. The northern region and desert areas (badia) showed comparable RSI at 1.0 and 1.1, respectively. Males younger than 15 years of age showed significantly higher surgical incidence than females of comparable age at a ratio of 1.6:1, whereas the number of female cases of different age groups over 15 years of age was consistently higher than that of males at a ratio of 1.25-2.5:1.0. The liver was the primary site of cyst development in 69.4% of the cases and the lung involvement accounted for 13.3% of the cases. Diagnosis of CE in Jordan relies mostly on imaging methods with serological techniques being rarely used for diagnosis. The frequency of CE recurrence was 27.5% of the cases, which may be attributed to the low use of chemotherapeutic antihelminthics among surgically treated cases.

Classification, follow-up and recurrence of hepatic cystic echinococcosis using ultrasound images

Ultrasound image and morphological structure of hepatic cystic echinococcosis (CE) were analysed in 277 human cases (385 hepatic hydatid cysts). These included 65 CE cases from community surveys carried out between 1995 and 2000 in 3 countries (China, Mongolia and Jordan) and 212 cases from a clinical hospital survey from Xinjiang, China. A new simplified WHO ultrasound classification for human CE was assessed, and considered useful. It is proposed that type, size and number in particular need to be included in the ultrasound classification of hepatic CE. For comparative purposes 6 categories of type were classified in the study as Type 0 to Type 5 (T0-T5): T0, univesicular without pathognomonic signs; T1, univesicular with pathognomonic signs; T2, cysts with sagging or floating laminated membrane; T3, cysts containing daughter cysts; T4, solid mass or mixed cysts; and T5, cysts with partial or full calcifications. This differs from the WHO classification wherein Type T3 cysts (daughter cysts present) are considered a pathological stage to occur in general prior to the sagging or floating membrane (T2) stage. Recurrent hydatid cysts in the liver were also studied based on morphological structures observed directly from surgical intervention. Case follow-up over 1-5 years since endocystectomy in the community surveys indicated 10% (2/10) recurrence of cysts in the residual surgical cavity. Recurrent CE included 2 (2/4) cases after percutaneous treatment.

The seroprevalences of cystic echinococcosis, and the associated risk factors, in rural- agricultural, bedouin and semi-bedouin communities in Jordan

Abstract An ELISA was used to determine the seroprevalence of cystic echinococcosis (CE), caused by Echinococcus granulosus, in representatives of the rural–agricultural, semi-bedouin and bedouin communities of Jordan. The knowledge, attitudes and practices (KAP) pertaining to the transmission of CE in such communities were also investigated. In the ELISA, serum samples from 2388 subjects were tested for IgG antibodies reacting with antigens in crude sheep hydatid fluid (CSHF). The rural–agricultural subjects were significantly more likely to be seropositive (11.4%) than the semi-bedouin (5.0%) or bedouin (3.7%), but male and female subjects were equally likely to be seropositive. Among the rural–agricultural and semi-bedouin subjects, those aged 11–20 years were most likely to be seropositive. Among the bedouin subjects, however, seroprevalence was highest for those aged 31–40 years. When the distribution of 59 seropositive subjects detected within 36 rural–agricultural households was investigated, 12 (33.3%) of the households were each found to have at least two seropositive members. Immunoblotting indicated that 27.1% of the seropositive rural–agricultural subjects showed immunoreactivity to at least one of the CSHF antigen-B components (of 8–12, 16 and 24 kDa). The living conditions, practices and lifestyles of the rural–agricultural, semi-bedouin and bedouin communities favour the spread of CE in Jordan and warrant an effective programme for the control of the disease.

A new focus of cutaneous leishmaniasis caused by Leishmania tropica in northern Jordan

An endemic focus of cutaneous leishmaniasis caused by Leishmania tropica was identified in the district of Bani Kinana, northern Jordan. Fifty-five autochthonous cases were detected from February to September 1994 in a population of about 50,000. Most cases (74.5%) were from the villages of Malka and Um-Quais. The lesions were typically small, dry and mostly located on the face and extremities. Multiple lesions were common. Incidence was higher in females than in males and familial clustering of cases was observed in houses on the outskirts of villages. A leishmanin survey showed a 23.3% positivity rate in the populations of Malka and Um-Quais. The rate of positivity was low in the younger age groups and increased with age. There was some evidence that the disease is a zoonosis in this focus.

Spleen hydatidosis in sheep from North Jordan

A total of 380 ewes of different age groups were inspected for spleen hydatidosis during the summer of 1985. Of these, 7.6% had cysts in the spleen. There was an increase in the prevalence of the disease with increasing age of the animal, reaching 11.8% in greater than or equal to 8-year-old ewes. Out of all the animals with spleen hydatidosis, 61.5% were found to have fertile cysts and, when classified, 46.7% were found to be fertile with a mean total number of protoscolices of 13.4 x 10(3) per cyst. The majority of the protoscolices were found to be viable (74%). Spleen hydatidosis which is mainly solitary seems to be secondary to the involvement of the liver or the liver and lung simultaneously. The importance of these aspects of spleen hydatidosis are discussed.