Search

Objective: To develop a better understanding of mechanisms of seizures and long-term epileptogenesis using neurocysticercosis., Methods: A workshop was held bringing together experts in epilepsy and epileptogenesis and neurocysticercosis., Results: Human neurocysticercosis and parallel animal models offer a unique opportunity to understand basic mechanisms of seizures. Inflammatory responses to degenerating forms and later-stage calcified parasite granulomas are associated with seizures and epilepsy. Other mechanisms may also be involved in epileptogenesis., Significance: Naturally occurring brain infections with neurocysticercosis offer a unique opportunity to develop treatments for one of the world's most common causes of epilepsy and for the development of more general antiepileptogenic treatments. Key advantages stem from the time course in which an acute seizure heralds a start of the epileptogenic process, and radiographic changes of calcification and perilesional edema provide biomarkers of a chronic epileptic state., (Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.)

Background: The recent avian influenza epidemic in Asia and the H1N1 pandemic demonstrated that influenza A viruses pose a threat to global public health. The animal origins of the viruses confirmed the potential for interspecies transmission. Swine are hypothesized to be prime "mixing vessels" due to the dual receptivity of their trachea to human and avian strains. Additionally, avian and human influenza viruses have previously been isolated in swine. Therefore, understanding interspecies contact on smallholder swine farms and its potential role in the transmission of pathogens such as influenza virus is very important., Methods: This qualitative study aimed to determine swine-associated interspecies contacts in two coastal areas of Peru. Direct observations were conducted at both small-scale confined and low-investment swine farms (n = 36) and in open areas where swine freely range during the day (n = 4). Interviews were also conducted with key stakeholders in swine farming., Results: In both locations, the intermingling of swine and domestic birds was common. An unexpected contact with avian species was that swine were fed poultry mortality in 6/20 of the farms in Chancay. Human-swine contacts were common, with a higher frequency on the confined farms. Mixed farming of swine with chickens or ducks was observed in 36% of all farms. Human-avian interactions were less frequent overall. Use of adequate biosecurity and hygiene practices by farmers was suboptimal at both locations., Conclusions: Close human-animal interaction, frequent interspecies contacts and suboptimal biosecurity and hygiene practices pose significant risks of interspecies influenza virus transmission. Farmers in small-scale swine production systems constitute a high-risk population and need to be recognized as key in preventing interspecies pathogen transfer. A two-pronged prevention approach, which offers educational activities for swine farmers about sound hygiene and biosecurity practices and guidelines and education for poultry farmers about alternative approaches for processing poultry mortality, is recommended. Virological and serological surveillance for influenza viruses will also be critical for these human and animal populations.

Taeniasis diagnosis is an important step in the control and elimination of both cysticercosis and taeniasis. We report the development of 2 serological taeniasis diagnostic tests using recombinant antigens rES33 and rES38 expressed by baculovirus in insect cells in an EITB format. In laboratory testing with defined sera from nonendemic areas, rES33 has a sensitivity of 98% (n = 167) and a specificity of 99% (n = 310) (J index: 0.97); rES38 has a sensitivity of 99% (n = 146) and a specificity of 97% (n = 275) (J index: 0.96). Independent field testing in Peru showed 97% (n = 203) of the taeniasis sera were positive with rES33, and 100% of the nontaeniasis sera (n = 272) were negative with rES33; 98% (n = 198) of taeniasis sera were positive with rES38, and 91% (n = 274) of the nontaeniasis sera were negative with rES38. Among the Peruvian sera tested, 17 of 26 Peruvian Taenia saginata sera were false positive with rES38 test. Both tests were also examined with cysticercosis sera, with a positive rate ranging from 21% to 46%. rES33 and rES38 tests offer sensitive and specific diagnosis of taeniasis and easy sample collection through finger sticks that can be used in large-scale studies. They are currently being used in cysticercosis elimination programs in Peru.

Cystic echinococcosis (CE) caused by the larval form of Echinococcus granulosus is a major public health problem in sheep-raising regions of the World. This study compared portable ultrasound with the enzyme-linked immunoelectrotransfer blot (EITB) assay as screening methods to estimate the prevalence of human CE in a remote village in the Peruvian Andes. Three hundred eighty-nine villagers were examined by portable ultrasound and blood samples were drawn by venipuncture. Sera were collected and tested for antibodies against CE using an EITB assay. Cystic lesions were classified based on their ultrasound morphologic characteristics. The prevalence of human CE using portable ultrasound and the EITB assay were 4.9% and 2.6%, respectively. Fifty-three percent of subjects with CE were EITB positive. Portable ultrasound was well received by the community, augmented CE detection and allowed a faster estimate of human infection than the EITB assay.

The pig is a vital link in the transmission cycle of Taenia solium, the cestode responsible for human-porcine cysticercosis. Infected pigs also represent an important source of economic loss to farmers in developing countries. Past efforts to find an adequate therapeutic regimen to treat this parasite disease in swine have failed because of low efficacy, high cost, side effects, or the need for multiple doses. In this randomized, no treatment-controlled study, the efficacy and safety of oxfendazole and praziquantel for the treatment of porcine cysticercosis were evaluated in 16 naturally infected pigs. Four groups of four pigs were treated with oxfendazole, praziquantel, oxfendazole plus praziquantel, or untreated. The pigs were humanely killed 12 weeks post-treatment, the number of cyst was counted, and parasite viability was assessed by cyst evagination. No detectable side effects were seen in any of the pigs. Praziquantel treatment alone appeared to reduce the number of cysts, but did not decrease the viability of the remaining parasites. Treatment with oxfendazole alone or oxfendazole plus praziquantel killed all of the parasites, and left only microcalcifications in the meat. Oxfendazole provides, for the first time, a practical, effective, inexpensive, and single-dose therapy for porcine cysticercosis.

The Gram-positive transposon Tn916 was introduced into two strains of Haemophilus paragallinarum by electroporation of the suicide plasmid pAM120 (pGL101::Tn916). Tetracycline resistant mutants of H. paragallinarum strains Tw-1 and 221 were recovered at frequencies of 2.1 x 10(-6) and 4.5 x 10(-7) per viable cell electroporated, respectively. Tn916 generates stable single insertions within different sites of the H. paragallinarum chromosome. One Tw-1::Tn916 mutant had the Tn916 insertion in the cryptic plasmid p250. This study indicates the potential use of Tn916 as a genetic tool for insertional mutagenesis of H. paragallinarum.

To determine the prevalence of cysticercosis in a rural area where the disease is endemic, the authors studied the seroepidemiology of human and porcine cysticercosis in a Peruvian jungle community (Maceda, Peru) in 1988 using an enzyme-linked immunoelectrotransfer blot (EITB) assay. Of the 371 sampled inhabitants, 30 (8%) were seropositive, most of whom were asymptomatic. After niclosamide therapy, four Taenia species worms were identified in the seropositive group, compared with one in the control group (p = 0.06). Pigs were frequently infected: 44 of 133 (33%) were found positive for Taenia by tongue examination and 57 of 133 (43%) were positive by EITB. In 69% of the sampled households that had pigs, there was at least one seropositive pig. The number of pigs diagnosed positive by the tongue examination was significantly greater in households that had latrines than in those that did not. Cysticercosis is a common but usually asymptomatic infection that affects both humans and pigs in the high jungle areas of Peru.

Patients with chronic spinal cord injury (SCI) and end-stage renal disease (ESRD) exhibit antithrombin III deficiency and several other coagulation abnormalities. In view of increasing recognition of protein C (PC) as an important, naturally occurring anticoagulant and fibrinolytic factor, we studied plasma PC in this population. PC antigen concentration and its anticoagulant activity were measured in nine SCI men with ESRD maintained on hemodialysis and in a control group of ten normal able-bodied men. The results showed a significant increase in PC anticoagulant activity in the SCI group. Consequently, the ratio of the PC activity to its concentration, which is a measure of the functional integrity of PC molecule, was markedly depressed. These findings are indicative of the presence of inactive or abnormal PC in SCI-ESRD patients and may suggest its in vivo activation. The combination of impaired PC activity shown in this study, with previously demonstrated antithrombin III deficiency and other coagulation abnormalities, is suggestive of a hypercoagulable state.