Toxocariasis: a silent threat with a progressive public health impact

Background: Toxocariasis is a neglected parasitic zoonosis that afflicts millions of the pediatric and adolescent populations worldwide, especially in impoverished communities. This disease is caused by infection with the larvae of Toxocara canis and T. cati, the most ubiquitous intestinal nematode parasite in dogs and cats, respectively. In this article, recent advances in the epidemiology, clinical presentation, diagnosis and pharmacotherapies that have been used in the treatment of toxocariasis are reviewed. Main text: Over the past two decades, we have come far in our understanding of the biology and epidemiology of toxocariasis. However, lack of laboratory infrastructure in some countries, lack of uniform case definitions and limited surveillance infrastructure are some of the challenges that hindered the estimation of global disease burden. Toxocariasis encompasses four clinical forms: visceral, ocular, covert and neural. Incorrect or misdiagnosis of any of these disabling conditions can result in severe health consequences and considerable medical care spending. Fortunately, multiple diagnostic modalities are available, which if effectively used together with the administration of appropriate pharmacologic therapies, can minimize any unnecessary patient morbidity. Conclusions: Although progress has been made in the management of toxocariasis patients, there remains much work to be done. Implementation of new technologies and better understanding of the pathogenesis of toxocariasis can identify new diagnostic biomarkers, which may help in increasing diagnostic accuracy. Also, further clinical research breakthroughs are needed to develop better ways to effectively control and prevent this serious disease

The Mitochondrial Genome of Toxocara canis

Toxocara canis (Ascaridida: Nematoda), which parasitizes (at the adult stage) the small intestine of canids, can be transmitted to a range of other mammals, including humans, and can cause the disease toxocariasis. Despite its significance as a pathogen, the genetics, epidemiology and biology of this parasite remain poorly understood. In addition, the zoonotic potential of related species of Toxocara, such as T. cati and T. malaysiensis, is not well known. Mitochondrial DNA is known to provide genetic markers for investigations in these areas, but complete mitochondrial genomic data have been lacking for T. canis and its congeners. In the present study, the mitochondrial genome of T. canis was amplified by long-range polymerase chain reaction (long PCR) and sequenced using a primer-walking strategy. This circular mitochondrial genome was 14162 bp and contained 12 protein-coding, 22 transfer RNA, and 2 ribosomal RNA genes consistent for secernentean nematodes, including Ascaris suum and Anisakis simplex (Ascaridida). The mitochondrial genome of T. canis provides genetic markers for studies into the systematics, population genetics and epidemiology of this zoonotic parasite and its congeners. Such markers can now be used in prospecting for cryptic species and for exploring host specificity and zoonotic potential, thus underpinning the prevention and control of toxocariasis in humans and other hosts

Zanieczyszczenie gleby jajami Toxocora spp. na terenie Krakowa i pobliskich wsi

The distribution of Toxocara spp. eggs was studied in the Kraków city and nearby villages Grodkowice and Łążkowice. In Kraków out of 80 samples surveyed 30% were positive and the mean egg density was 3.7 eggs/100g soil. Court-yards and squares in the centre of the city were the most heavily contaminated areas (58% samples positive). In two nearby villages Toxocara spp. eggs were present in 16% samples examined and the mean egg density was 0.8 eggs/100g soil. Almost 90% of Toxocara spp. eggs recovered were infective. At least 80% of the eggs were classified as T. cati by egg's morfology

Biologiczne skażenie gleby na terenach popowodziowych we Wrocławiu

The distribution of geohelminth eggs on the appertment backyards of Wrocław city after flood disaster was studied. Out of 100 soil samples examined 17% were positive. Toxocara spp.eggs were present in 6% samples examined, Aacaris spp. in 2% and other eggs (Capilaria sp. and Trichuris vulpis) in 9% samples examined. Soil contamination of Wrocław area was much less than in other cities of Poland and Europe. The prevalence of geohelminth eggs on flooded areas was very similar to that on the not-flooded areas although the number of eggs recovered was twice as high on flooded areas

Wplyw czynnikow biotycznych na jaja Ascaris spp.

There are many organisms that influence development and survival of eggs of Ascaris sp. Fungi, Acari, Collembola and bacteria are the most important among them. They participate mainly in autodehelminthisation processes of environment