Focus: Zoonotic Disease: Zoonotic Ocular Onchocercosis by Onchocerca lupi

The parasitic filarioid Onchocerca lupi causes ocular disease characterized by conjunctivitis and nodular lesions. This nematode was first described in 1967 in a wolf from Georgia, and since then cases of infection from dogs and cats with ocular onchocercosis and sporadically from humans also with subcutaneous and cervical lesions caused by O. lupi have been reported from the Middle East, Europe, and North America. Due to its zoonotic potential, this parasitic infection has gained attention in the past 20 years. Phylogenetic studies have highlighted the recent divergence of O. lupi from other Onchocerca spp. and the importance of domestication in the evolutionary history of this worm. Moreover, the finding of an O. lupi genotype associated with subclinical and mild infection in the Iberian Peninsula, raises important questions about the pathogenicity of this presently enigmatic parasite.     

Risk factors for helminth infections in a rural and a peri-urban setting of the Dongting Lake area, People's Republic of China

Schistosomiasis japonica and soil-transmitted helminthiasis are endemic parasitic diseases in the People’s Republic of China (PR China). As very few studies have reported on the distribution and interaction of multiple species helminth infections, we carried out a comparative study of households in a rural village and a peri-urban setting in the Dongting Lake area of Hunan province in November and December 2006 to determine the extent of single and multiple species infections, the underlying risk factors for infection, and the relationships with clinical manifestations and self-reported morbidity. In each household, stool samples were collected and subjected to the Kato-Katz method for identifying Schistosoma japonicum, Ascaris lumbricoides, hookworm and Trichuris trichiura infections. Clinical examinations were performed and questionnaire surveys conducted at both household and individual subject levels. Complete parasitological, clinical and questionnaire data were obtained for 1,298 inhabitants of the two settings. The overall prevalences of single infections of S. japonicum, A. lumbricoides, hookworm and T. trichiura were 6.5%, 5.5%, 3.0% and 0.8%, respectively; the majority of the infections were of light intensity. We found significant negative associations between wealth and infections with S. japonicum and A. lumbricoides. Clinical manifestations of splenomegaly, hepatomegaly and anaemia were prevalent (9.0%, 3.7% and 10.9%, respectively), the latter two being significantly (P < 0.05) associated with schistosomiasis. Self-reported symptoms were more common among females but there was considerable under-reporting in both sexes when relying only on spontaneous recall. Our findings may guide the design and targeting of a more equitable, comprehensive and integrated parasitic disease control programme in Hunan province and in other areas of PR China.     

A Human Case of Hymenolepis diminuta in a Child from Eastern Sicily

We report a case of Hymenolepis diminuta infection in a 2-year-old child living in a suburban area of Catania, Italy. This case was initially referred to us as Dipylidium caninum infection, which was not cured after being treated twice with mebendazole. However, by analyzing the clinical presentation and stool samples we arrived to the diagnosis of H. diminuta infection. The case presented with atypical allergic manifestations which had never been reported as clinical features of symptomatic H. diminuta infection; remittent fever with abdominal pain, diffuse cutaneous itching, transient thoracic rash, and arthromyalgias. The patient was treated with a 7-day cycle of oral niclosamide, which proved to be safe and effective. This case report emphasizes that a correct parasitological diagnosis requires adequate district laboratories and trained personnel. In addition, we recommend the importance of reporting all H. diminuta infection cases, in order to improve knowledge on epidemiology, clinical presentation, and treatment protocols.     

Lutz's spontaneous sedimentation technique and the paleoparasitological analysis of sambaqui (shell mound) sediments

Parasite findings in sambaquis (shell mounds) are scarce. Although the 121 shell mound samples were previously analysed in our laboratory, we only recently obtained the first positive results. In the sambaqui of Guapi, Rio de Janeiro, Brazil, paleoparasitological analysis was performed on sediment samples collected from various archaeological layers, including the superficial layer as a control. Eggs of Acanthocephala, Ascaridoidea and Heterakoidea were found in the archaeological layers. We applied various techniques and concluded that Lutz''s spontaneous sedimentation technique is effective for concentrating parasite eggs in sambaqui soil for microscopic analysis.     

Joint modelling of repeated measurements and event time: Application to performance traits and survival of lambs bred in sub-humid tropics

We considered the analysis of a study for Dorper, Red Maasai and crossbred lambs born over a period of 6 years at the Diani Estate, Kenya. The study was designed to compare survival and performance traits of genotypes with differing susceptibilities to helminthiasis. The available data include information on time to death and repeated measurements of body weight, packed cell volume (PCV) and faecal egg count (FEC) of the animals. In the paper, we consider joint modelling of the survival time and the repeated measurements. Such an approach allows to account for the possible association between the survival and repeated measurement processes. The advantages and limitations of the joint modelling are discussed and illustrated using the Diani Estate study data.     

Highlights of human toxocariasis

Human toxocariasis is a helminthozoonosis due to the migration of Toxocara species larvae through human organism. Humans become infected by ingesting either embryonated eggs from soil (geophagia, pica), dirty hands or raw vegetables, or larvae from undercooked giblets. The diagnosis relies upon sensitive immunological methods (ELISA or western-blot) which use Toxocara excretory-secretory antigens. Seroprevalence is high in developed countries, especially in rural areas, and also in some tropical islands. The clinical spectrum of the disease comprises four syndromes, namely visceral larva migrans, ocular larva migrans, and the more recently recognized "common" (in adults) and "covert" (in children) pictures. Therapy of ocular toxocariasis is primarily based upon corticosteroids use, when visceral larva migrans and few cases of common or covert toxocariasis can be treated by anthelmintics whose the most efficient appeared to be diethylcarbamazine. When diagnosed, all of these syndromes require thorough prevention of recontamination (especially by deworming pets) and sanitary education.     

The relative contribution of co-infection to focal infection risk in children

Co-infection is ubiquitous in people in the developing world but little is known regarding the potential for one parasite to act as a risk factor for another. Using generalized linear mixed modelling approaches applied to data from school-aged children from Zanzibar, Tanzania, we determined the strength of association between four focal infections (i.e. Ascaris lumbricoides, Trichuris trichiura, hookworm and self-reported fever, the latter used as a proxy for viral, bacterial or protozoal infections) and the prevalence or intensity of each of the helminth infections. We compared these potential co-infections with additional risk factors, specifically, host sex and age, socioeconomic status and physical environment, and determined what the relative contribution of each risk factor was. We found that the risk of infection with all four focal infections was strongly associated with at least one other infection, and that this was frequently dependent on the intensity of that other infection. In comparison, no other incorporated risk factor was associated with all focal infections. Successful control of infectious diseases requires identification of infection risk factors. This study demonstrates that co-infection is likely to be one of these principal risk factors and should therefore be given greater consideration when designing disease-control strategies. Future work should also incorporate other potential risk factors, including host genetics which were not available in this study and, ideally, assess the risks via experimental manipulation.     

Developmental stage‐dependent influence of environmental factors on growth of rural Sundanese children in West Java,Indonesia

This study investigated the growth trajectories and the relative relevance levels of nutrition, disease, and hormonal status at various developmental stages among children in adverse environments to provide population‐based empirical evidence for the life history theory. Three years of longitudinal anthropometric data in 1‐year intervals were obtained from 418 boys and girls aged 0 to 12 years at recruitment. Following the final measurement, the main survey, which included blood and feces sampling, 3‐h interval food consumption recall surveys for energy and nutrient intakes and anthropometry, was performed. Blood and feces were used for detecting, respectively, anemia and hormonal (IGF‐I and IGFBP‐3) levels as well as intestinal helminthiasis (Ascaris, Trichuris, and hookworm). The major findings of this study are summarized as follows: 1) the growth velocity of the subject children lagged behind international standards during childhood and juvenility but caught up during early adolescence; 2) diseases, both intestinal helminths and anemia, had significant effects on growth in childhood but not at older ages; and 3) hormonal status significantly affected growth in the children, with its highest significance in early adolescence. A larger growth than international standards in early adolescence likely follows programmed hormonal mechanisms after the onset of puberty. The onset of puberty might be associated with adequate amounts of nutrient intake and be mediated by hormonal function, because the IGF‐IZ score was significantly correlated with energy and protein intakes at the transitional period from juvenility to adolescence, when puberty occurs. Am J Phys Anthropol 157:94–106, 2015. © 2015 Wiley Periodicals, Inc.     

Transmission of Toxocara canis via ingestion of raw cow liver: a cross-sectional study in healthy adults

The aim of this study is to ascertain the relationship between ingestion of raw cow liver and Toxocara canis infection. A total of 150 apparently healthy adults were divided into 2 groups; 1 group consisted of 86 adults with positive results of Toxocara ELISA, and the other group of 64 adults with negative results. One researcher collected the history of ingestion of raw cow liver within 1 year and recent history of keeping dogs. Among 86 seropositive adults for T. canis, 68 (79.1%) had a recent history of ingestion of raw cow liver. Multivariate statistical analysis showed that a recent ingestion of raw cow liver and keeping dogs were related to an increased risk of toxocariasis (odds ratios, 4.4 and 3.7; and 95% confidence intervals, 1.9-10.2 and 1.2-11.6, respectively). A recent history of ingestion of raw cow liver and keeping dogs was significantly associated with toxocariasis.