Parasitic contamination of fresh vegetables sold in open markets: a public health threat / Contaminação parasítica de vegetais frescos vendidos em mercados abertos: uma ameaça para a saúde pública

Vegetables eating raw are a leading source of transmission of infective forms of pathogenic internal parasites among human beings. This research was conducted from April to October, 2017 to assess the parasitic contamination of vegetables sold at main vegetable markets in districts Lower Dir and Peshawar, Pakistan. Eight hundred specimens of different vegetables were purchased and soaked in physiological saline solution, shaken with a mechanical shaker for 20 minutes and processed by sedimentation concentration method. Results revealed that only 19.7% (n=158/800) of the vegetables were found to be contaminated with single or multiple parasite species. Ascaris lumbricoides (the large round worm) 12.3% (n=99/800) was the most commonly detected pathogen and Taenia saginata (the beef tapeworm) 1.62% (n=13/800) was the least frequently detected one. Interestingly, significant p value (p>0.05 at 95%CI) between the number of examined and contaminated for all the variables studied including education status of the vendors, markets location, type of vegetables, means of display, washed before display, washing source of water and market type. The findings of this study evidenced that consumption of raw vegetables possesses great risk of getting parasitic infections in Lower Dir and Peshawar districts, Pakistan. Instructing the sellers and the public about parasitic disease transfer and their hygiene can reduce the infection rate of parasites of human origin.

Os vegetais crus são a principal fonte de transmissão de formas infecciosas de parasitas internos patogênicos entre os seres humanos. Esta pesquisa foi realizada de abril a outubro de 2017 para avaliar a contaminação parasitária de vegetais vendidos nos principais mercados de vegetais nos distritos de Lower Dir e Peshawar, Paquistão. Oitocentos exemplares de diferentes vegetais foram adquiridos e embebidos em solução salina fisiológica, agitados em agitador mecânico por 20 minutos e processados pelo método de concentração por sedimentação. Os resultados revelaram que apenas 19,7% (n = 158/800) das hortaliças estavam contaminadas com uma ou várias espécies de parasitas. Ascaris lumbricoides (o verme redondo grande) 12,3% (n = 99/800) foi o patógeno mais comumente detectado e Taenia saginata (a tênia da carne) 1,62% (n = 13/800) foi o menos freqüentemente detectado. Curiosamente, valor de p significativo (p> 0,05 em IC de 95%) entre o número de examinados e contaminados para todas as variáveis estudadas incluindo escolaridade dos vendedores, localização dos mercados, tipo de vegetais, meios de exposição, lavado antes da exposição, fonte de lavagem de água e tipo de mercado. Os resultados deste estudo evidenciaram que o consumo de vegetais crus possui grande risco de contrair infecções parasitárias nos distritos de Lower Dir e Peshawar, no Paquistão. Instruir os vendedores e o público sobre a transferência de doenças parasitárias e sua higiene pode reduzir a taxa de infecção de parasitas de origem humana.

Identification of risk areas and practices for Taenia saginata taeniosis/cysticercosis in Ethiopia: a systematic review and meta-analysis.

BACKGROUND: Bovine cysticercosis (BCC) is an infection of cattle with the metacestode stage of Taenia saginata, the beef tapeworm, which causes taeniosis in humans. BCC is responsible for considerable economic losses in the meat sector worldwide. This systematic review and meta-analysis summarizes the prevalence, risk factors and treatment efforts made so far on T. saginata infections in Ethiopia, providing a detailed analysis of different factors influencing the varying prevalence estimates in Ethiopia to gain more insight into the occurrence and risk factors of T. saginata taeniosis and cysticercosis to date. METHODS: A systematic review and meta-analysis was conducted on data collected from published and grey literature accessed through an electronic database and manual search. RESULTS: The literature search resulted in 776 outputs of which 132 conformed to the predefined criteria. The average zonal prevalence of meat inspection-based BCC ranged from 2% in Buno-Bedele to 24.6% in Sidama zone. The pooled prevalence of BCC was influenced by the number of muscle/organs inspected, ranging from 3.4% (95% CI: 1.7-5.1%) using fewer predilection sites to 19.4% (95% CI: 13.3-25.4%) using inspection of a maximum number of predilection sites. None of the tested variables were significantly associated with BCC. Questionnaire-based taeniosis ranged between 19.0% in Halaba special woreda to 70.0% in Gedeo zone and stool test-based taeniosis varied from 0.6% in central Tigray to 10.7% in Gurage zone. Questionnaire-based prevalence of taeniosis was higher in people with a frequent raw beef consumption habit (pooled OR, pOR: 10.5, 95% CI: 6.0-17.9), adults (pOR: 2.5, 95% CI: 1.7-3.6), men (pOR: 2.8, 95% CI: 2.1-3.6), and Christians (pOR: 2.0, 95% CI: 1.4-2.8) compared to less frequent raw beef consumers, younger people, women and Muslims, respectively. CONCLUSIONS: This review revealed a widespread but variable occurrence of BCC and taeniosis in Ethiopian regions and zones, urging for harmonized and enhanced detection for improved control of the parasite. Accurate prevalence estimates using more sensitive tests, detailed risk factor analysis, as well as data on financial losses are needed to develop effective control strategies for the Ethiopian epidemiologic condition.

In vitro model of postoncosphere development, and in vivo infection abilities of Taenia solium and Taenia saginata.

Taenia solium is known to cause human cysticercosis while T. saginata does not. Comparative in vitro and in vivo studies on the oncosphere and the postoncospheral (PO) forms of T. solium and T. saginata may help to elucidate why cysticercosis can occur from one and not the other. The aim of this study was to use in vitro culture assays and in vivo models to study the differences in the development of the T. solium and T. saginata oncosphere. Furthermore, this study aimed to evaluate the expression of cytokines and metalloproteinases (MMPs) in human peripheral blood mononuclear cells (PBMCs), which were stimulated by these oncospheres and PO antigens. T. solium and T. saginata activated oncospheres (AO) were cultured in INT-407 and HCT-8 intestinal cells for 180 days. The T. solium began to die while the T. saginata grew for 180 days and developed to cysticerci in INT-407 cells. Rats were inoculated intracranially with AO and PO forms of either T. saginata or T. solium. Rats infected with T. solium AO and PO forms developed neurocysticercosis (NCC), while those infected with the T. saginata did not. Human PMBCs were stimulated with antigens of AO and PO forms of both species, and the production of cytokines and metalloproteinases (MMPs) was measured. The T. solium AO antigen stimulated a higher production of IL-4, IL-5, IL-13, IFN-γ, and IL-2 cytokines compared to T. saginata AO. In the PO form, the T. saginata PO antigen increased the production of IL-4, IL-5, IL-13, IFN-γ, IL-1ß, IL-6, IL-10, TNF-α and IL-12 cytokines compared to T. solium, suggesting that this global immune response stimulated by different forms could permit survival or destruction of the parasite depending of their life-cycle stage. Regarding MMPs, T. solium AO antigen stimulated a higher production of MMP-9 compared to T. saginata AO antigen, which may be responsible for altering the permeability of intestinal cells and facilitating breakdown of the blood-brain barrier during the process of invasion of host tissue.

A co-infection case report of Taenia saginata in a patient with subclinical clonorchiasis confirmed by the combination of diagnostic tools.

BACKGROUND: Clonorchiasis is the common parasitic infection in the general population of the Republic of Korea, however, taeniasis is scarcely reported recently. Here, we describe a case of co-infection with the cestode T. saginata in a patient with subclinical clonorchiasis diagnosed by a combination of diagnostic tools in Korea. CASE PRESENTATION: A 56-year-old man visited the hospital having passed proglottids in his stool for the past two months and brought a stool sample with segments to our hospital. He had no abdominal symptoms, such as nausea, vomiting, abdominal pain, diarrhea, or constipation. He used to consume raw beef and fish frequently. We could not find evidence of gravid proglottids which contain fully developed uteri filled with ova or branched uterine structures, within the submitted sample. To identify the tapeworm species, we carried out molecular analyses on the proglottids. The cox1 and ef1a sequences had a 100% match with those of T. saginata and differed from the sequences of the other Taenia species. Upon examination of stool samples fixed by formalin-ether concentration method, no Taenia species ova were observed in 10 slides. Instead, C. sinensis ova were observed, despite the level of IgG specific to C. sinensis being within the normal range. The patient was treated with praziquantel (25 mg/kg, three times a day) for 3 days, and subsequently C. sinensis ova were not found in his stool. CONCLUSION: Our case indicates that a combination of morphological, serological, and molecular diagnostic tools should be used for the accurate diagnosis of subclinical parasitic infections.

Taenia saginata a rare cause of acute cholangitis: a case report.

Parasitic infestations of the galdbladder and biliary tract are quite rare. Taenia saginata is an intestinal helmint and patients harbouring adult T.saginata tapeworms are mostly asymptomatic and discharge only fecal proglottids. In some cases there might be nonspecific symptoms like vomiting, nausea, epigastric pain, diarrhea and weight loss. Tenia saginata is a also rare cause of ileus, pancreatitis, cholecystitis and cholangitis. We report a case of acute cholangitis caused by T. saginata presenting with fever, nausea, vomiting, jaundice and right upper quadrant pain. Although parasites are not an uncommon cause of cholangitis especially in diseaseendemic areas like the Far East, this is not true for T. saginata causing acute cholangitis.

Development of Taenia saginata asiatica metacestodes in SCID mice and its infectivity in human and alternative definitive hosts.

Development of Taenia saginata asiatica metacestodes in SCID mice, and its infectivity in humans, golden hamsters, and Mongolian gerbils as alternative definitive hosts, were investigated. Cysticerci were recovered from SCID mice that were subcutaneously injected with hatched oncospheres of T. s. asiatica. The morphological changes of metacestodes were observed. The recovered cysticerci were fed to gerbils, hamsters and humans, to check for their infectivity. Tapeworms were recovered from gerbils and hamsters fed with 20 to 45 week-old cysticerci, and proglottids excretions were observed in human volunteers fed with 45 week-old cysticerci. However, no tapeworms were recovered from gerbils fed with 10 week-old cysticerci. Our results suggest that T. s. asiatica oncospheres needed more than 20 weeks to develop to maturity in SCID mice to be infective to both their natural and alternative definitive hosts.

Jejunal perforation caused by morphologically abnormal Taenia saginata saginata infection.

We report a case of jejunal perforation caused by infection with taeniid tapeworm possessing unusual morphology that has not been previously described. Among five cestodes recovered during operation, one exhibited a bifurcation at the posterior end and the other harbored a lateral branching of immature segments from the main strobila. By sequence analysis of the mitochondrial cytochrome c oxidase I gene and the 28S rRNA gene has confirmed them to be Taenia saginata saginata.