Anisakis pegreffii Larvae in Sphyraena viridensis and Description of Granulomatous Lesions

The aim of the present study was to describe gastric granuloma caused by Anisakis pegreffii in Sphyraena viridensis caught in the central Mediterranean Sea. Sixty-eight S. viridensis specimens were collected from different fish markets on the east coast of Sicily. Coelomic organs were observed both macroscopically and with the aid of stereomicroscope. Parasite specimens and lesioned tissues were collected for identification, histological and molecular analyses. Twelve specimens (p = 17.6%) were positive for the presence of nematode larvae, morphologically identified as larvae of Anisakis sp., with values of mean abundance and mean intensity of 0.9 and 4.8, respectively. One large female specimen showed massive parasite infection associated with nodular lesions of the gastric wall. By histology, several nematode larvae encysted through the gastric wall were found. The parasite bodies were surrounded by a granulomatous reaction made up of macrophages, epithelioid cells, some lymphocytes and an external connective sheet. Molecular analysis of 18S rRNA and cox2 genes from Anisakis sp. collected larvae, identified them as A. pegreffii. The lesions here described, though macroscopically superimposable on human eosinophilic granuloma, microscopically showed significant differences in the inflammatory cells involved and in the type of immune reaction.

Infection of Mammary Glands of Small Mammals in Eastern North America by Helminths

To determine whether small mammals living in natural settings harbor helminth infections in their mammary glands, we conducted a survey of helminths infecting rodents and soricimorphs in three widespread locations in the eastern United States: states of New York, Tennessee, and Georgia. We examined all the primary organs in all hosts, and identified all helminths. We also excised the complete mammary glands within their subcutaneous fat pads, then stained and mounted each whole mammary gland set for microscopical examination. A total of 53 individual hosts were examined, including 32 Peromyscus spp., 11 Mus musculus, 5 Sigmodon hispidus, 4 Clethrionomys gapperi, and 1 Blarina carolinensis. Helminths collected included Heligmosomoides sp., Hymenolepisdiminuta, Hymenolepis nana, Pterygodermatites peromysci, Schistosomatium douthitti, Syphacia obvelata, Syphacia sigmodontis, and Trichostrongylus sigmodontis. Four S. hispidus were infected by T. sigmodontis in the small intestine; in all four, we also found nematode larvae in lactiferous duct lumen and lactogenic tissue of the mammary glands. We were unable to identify the species of nematode larvae, but the co-occurrence with T. sigmodontis in all cases may suggest an association. Future studies should seek to identify such larvae using molecular and other methods, and to determine the role of these mammary nematode larvae in the life cycle of the identified species. No other host species harbored helminths in the mammary glands. Overall, our results suggest that mammary infections in wild small mammals are not common, but warrant inclusion in future surveys.

A case report of asymptomatic cutaneous larva migrans

<p>Cutaneous larvae migrans or creeping eruption is a serpiginous cutaneous eruption caused by the accidental penetration and migration of animal hookworm (nematode) larvae through the epidermis and subcutaneous tissue. The infection occurs most frequently in warmer climates and is associated with pruritus and burning sensation<span style="text-decoration: line-through;">s</span>. We report a case of 48 years old farmer with vesicular lesion on left ankle progressing into a serpiginous track on the skin surface without any characteristic symptoms. Treatment with oral and topical drugs led to successful resolution of lesions within 10 days.</p>

Anisakid and Raphidascaridid parasites in Trachurus trachurus: infection drivers and possible effects on the host’s condition

This study investigated the distribution of nematode larvae of Anisakidae and Raphidascarididae (genera Anisakis and Hysterothylacium) in Trachurus trachurus (Linnaeus, 1758) in the Ligurian and central-northern Tyrrhenian Seas. The relationship between the number of parasites and the length and weight parameters of the fish was assessed, and the possible effect of the parasites on the condition factor was evaluated. A total of 190 T. trachurus specimens were collected in July 2019. Parasites were found in 70 individuals. A total of 161 visible larvae were collected in the viscera. Morphological analysis revealed the presence of Anisakis spp. in 55 fish and Hysterothylacium spp. in 15 fish, while 5 fish showed coinfection with both genera. The specimens subjected to PCR (n = 67) showed that 85% of the Anisakis larvae analyzed belonged to the species A. pegreffii, while the remaining 15% belonged to hybrids of A. pegreffii-A. simplex (s.s.). A total of 58% (n = 7) of the Hysterothylacium larvae analyzed belonged to the species H. fabri, while 42% belonged to the species H. aduncum. Our results support the hypothesis that infection with these parasites does not affect the condition of the fish host analyzed, and that body size and depth are major drivers in determining infection levels with Anisakid and Raphidascaridid nematodes.

Biological control of nematodes by nematode-trapping fungi Duddingtonia flagrans in naturally infected sheep in southern Brazil

The aim of this study was to evaluate the anti-helminthic effect of a commercial formulation Bioverm® (Duddingtonia flagrans) in 28 sheep naturally infected with gastrointestinal nematodes. Animals were classified into two groups: G1 (n=14) treated with nematophagous fungi and G2 (n=14) untreated control. The efficacy of the anti-helminthic drug was assessed based on the egg count per gram of feces (EPG) of strongyles, larval culture, hemogram, leukogram, plasma protein levels, mucosal coloration using the FAMACHA© method, animals body weight, and evaluating the ocular mucosa for the FAMACHA© anemia guide were performed at days 0, 30, 60, 90, 120, 150, and 180. Additionally, the nematode larvae were quantified in the dry matter of the pastures of both groups. Results showed that the EPG was significantly decreased in animals receiving nematophagous fungi from D30 until the experiment end. The most common nematode genus was Haemonchus (63%), followed by Cooperia (23%) and Trichostrongylus (15%). Based on the fecal egg count reduction test (FECRT), treated animals showed a reduction of fecal egg count of 58.9%, 8.6, 92.8%, 96.4%, and 96.2%, at D30, D60, D90, D120, and D180, respectively. The absolute values of red blood cells and leukocytes were significantly increased at D60 and D90, respectively, in the treated animals. A significant weight gain was observed in the treated ewes at the end of the experiment; however, there was no correlation between the EPGs values and hematocrit with the FAMACHA© degrees of animals in both experimental groups. The mean EPG of both groups and the number of infectious larvae in the pastures were not directly proportional. In conclusion, nematophagous fungi contributed to decreased parasitic load in sheep, and consequently, improve animal performance; they can be a suitable alternative to reduce problems associated with nematode infections.

High prevalence and intensity of fish nematodes with zoonotic potential in the Brazilian Amazon, including a brief reflection on the absence of human infections

This study aimed to characterize the prevalence, mean abundance, and mean intensity of potential fish-borne zoonotic nematode larvae infecting the predator fish Hoplias aff. malabaricus from the Tapajós River, in the municipality of Santarém, in the Brazilian Amazon. After capture, the specimens of H. aff. malabaricus were analyzed for infection by Contracaecum sp. and Eustrongylides sp. third-stage larvae, and the prevalence, mean abundance, and mean intensity were calculated. A literature search was carried out to clarify the relationship between these indicators and eventual human cases of infection in the Amazon region. Third-stage larvae of nematodes of the Contracaecum and Eustrongylides genera were found in the specimens of H. aff. malabaricus sampled from the Tapajós River. The prevalence of Contracaecum larvae was 100%, while its mean abundance and mean intensity were both 54.8 larvae/fish. The prevalence of Eustrongylides larvae was 62.9%, and its mean abundance and mean intensity were 1.8 and 2.8 larvae/fish, respectively. Despite the high prevalence and intensity values, there are no cases of human infection by these nematode larvae in the Brazilian Amazon reported. The absence of human infections by these nematode larvae in the Brazilian Amazon despite the high prevalence/intensity of Contracaecum and Eustrongylides larvae and the high consumption of fish in the region, is most probably due to the fact that the local populations do not eat raw or undercooked fish. However, it is noteworthy that the absence of zoonotic cases in the region is based only on the examination of the available published papers. A better knowledge of the situation would require surveying hospitals and clinics, and data from the region’s medical treatment facilities. However, the authors consider that cases of human infection, if any, are extremely rare, mainly due to the eating habits of the local population. KEY WORDS: Amazon basin; freshwater fish; public health; parasitic infection; zoonosis.

Lymphatic filariasis: a snap shot of a neglected tropical disease

Lymphatic filariasis (LF) is a leading cause of disability worldwide and one of the most crippling and stigmatizing tropical diseases. LF transmission is widespread throughout regions of West Africa, coastal and south-eastern Africa, East and South-east Asia, South western India, Western Pacific and parts of South and Central America. The disease manifests as disfiguring pathology caused by microfilariae larvae damage to lymph vessels and nodes. LF is spread by mosquitoes that have been infected with filarial nematode larvae and about a billion people in 52 countries are thought to be at risk of contracting the disease on a global scale. Complex immune responses to filaria and their endosymbionts cause the pathologies associated with lymphatic filariasis. Several studies show that non-climatic factors that may be responsible for LF transmission at the micro level include environmental, social, economic, and demographic factors. Currently, the infection is controlled by mass drug administration regimens, vector control strategies and management of morbidities. This review discusses the ecological drivers of lymphatic filariasis transmissions in endemic hotspots.