Molecular differentiation of Entamoeba spp. in a rural community of Loja province, South Ecuador.

Although previous epidemiological surveys in Ecuador indicate the presence of Entamoeba histolytica, prevalence data of this parasite remain scarce. Most of the studies were based on microscopic examination, which does not allow a morphological differentiation from the non-pathogenic Ent. dispar and Ent. moshkovskii. In the present study, 674 stool samples from a South Ecuadorian rural community were screened for Entamoeba spp. Subsequently, molecular identification was performed on 101 samples containing Ent. histolytica/Ent. dispar/Ent. moshkovskii cysts. The study indicated the absence of Ent. histolytica in this South Ecuadorian community and confirmed the difficulty of differentiating Entamoeba spp. based on morphological features.

Survey on porcine trichinellosis in Ecuador.

A survey on porcine trichinellosis was organised in Ecuador between 2000 and 2003. Blood samples were taken in slaughterhouses (study 1, n=2000; study 2, n=331) and in a remote village where pigs are free roaming (study 3, n=646) and examined by ELISA using excretory/secretory (E/S) antigens. Seven samples (0.35%) in study 1 and none of the samples of study 2 were serologically positive. Thirty-seven (5.72%) village pigs tested positive by E/S ELISA in study 3. Sero-positive results by the E/S ELISA in study 1 were confirmed by ELISA using beta-tyvelose antigen, and by immunoblot. Muscle samples taken from pigs slaughtered in the abattoir (study 2) and from animals that showed a positive serology in study 3 were examined by trichinoscopy and artificial digestion. These techniques failed to demonstrate the presence of muscle larvae. The results of this survey need confirmation, but suggest that Trichinella is present in Ecuador; however, prevalence and parasite burdens are likely to be very low. The likelihood of detecting trichinellosis are higher in traditional settings than in pigs raised on improved farms.

Assessing the burden of Taenia solium cysticercosis and echinococcosis.

This collection of articles provides an account of the papers delivered at the 19th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP)(held in New Orleans, LA, USA, from 10 to 14 August 2003) in a symposium session on assessing the burden of Taenia solium cysticercosis and echinococcosis organised and chaired by A. Lee Willingham III from the WHO/FAO Collaborating Center for Research and Training on Emerging and other Parasitic Zoonoses in Denmark and Peter M. Schantz from the Parasitic Diseases Division of the US Centers for Disease Control and Prevention, USA. The focus was on the persistence of the zoonotic parasitic diseases cysticercosis, caused by the pork tapeworm T. solium, and echinococcosis,caused by species of the tapeworm Echinococcus, and why these diseases are given very little attention on the national and international agendas in spite of the availability of tools to detect, treat,control and prevent them when it is quite clear in most instances that they are clearly associated with and help perpetuate poverty. A major reason for this is that in many endemic areas the presence and impact of these diseases are not known due to the lack of investigation and information thus policymakers are not aware of their burden and benefits of their control. Documentation is also needed to help increase awareness of the international community and hopefully result in financial and technical support being made available. Thus, burden assessments of cysticercosis and echinococcosis provide an essential evidence base for securing political will and financial and technical support as well as providing a basis for cost-benefit analysis of prevention and control efforts. In order to make an appropriate and full burden assessment one must consider the health, agricultural, social and other impacts of these parasitic zoonoses comprehensively. During the symposium presentations were given concerning current ongoing initiatives to assess the burden of cysticercosis and echinococcosis and examples of the impact of these diseases in both developing and developed countries were provided. In addition, cost factors related to vaccines for these cestode diseases were discussed and the possibilities for technical and financial support from multilateral agencies for assessments and interventions presented.

Taeniosis-cysticercosis in man and animals in the Sierra of Northern Ecuador.

Taenia solium is endemic in the Andean region of Ecuador. The recent rediscovery of Taenia saginata in humans urges to reconsider some assumptions in relation to the epidemiology of the taeniosis/cysticercosis complex in this country.Therefore, data were compiled on the infection of both tapeworms in man and animals in Pichincha and Imbabura provinces in the Andean region, north of Quito. On post mortem inspection 3 out of 806 (0.37%) carcasses had T. saginata metacestodes, however, 35 sera out of 869 (4.03%) showed circulating antigen in a monoclonal antibody-based sandwich ELISA (Ag-ELISA). Porcine cysticercosis was detected in 15 out of 2896 (0.52%) carcasses and 93 out of 1032 serum samples (9.01%) were positive in Ag-ELISA. In humans, 4.99% (215 out of 4306) cases of antigen positives were found, whereas coprological examination of 1935 stools resulted in 30 positive cases (1.55%). The limited number of adult tapeworms (29) that were collected does not allow firm conclusions on the proportion of each species, but in total 21 specimen were identified as T. saginata and 8 as T. solium. These data have been discussed in view of the epidemiology of human cysticercosis.