Global goat! Is the expanding goat population an important reservoir of Cryptosporidium?

Goats are a primary or additional income source for many families in resource-poor areas. Although often considered inferior to other livestock, the resilience of goats and their ability to thrive in a range of environments means that that they are of particular value. Furthermore, goats emit less methane than other livestock species. In these same areas, it is well-documented that cryptosporidiosis has a substantial impact on infant morbidity and mortality, as well as reducing child growth and development. As Cryptosporidium also causes diarrheal disease in goats, the question arises whether goats may represent a reservoir of infection to humans. Epidemiological studies regarding the potential for transmission of Cryptosporidium between goats and humans have largely concluded that Cryptosporidium species infecting goats are not zoonotic. However, these studies are mostly from developed countries, where goat husbandry is smaller, management routines differ greatly from those of developing countries, contact between goats and their owners is more limited, and cryptosporidiosis has less impact on human health. In this article, background information on goat husbandry in different countries is provided, along with information on Cryptosporidium prevalence among goats, at both the species and sub-species levels, and the potential for zoonotic transmission. The intention is to indicate data gaps that should be filled and to increase awareness of the role of goats as providers for low-income families, often living in areas where cryptosporidiosis is endemic and where appropriate baseline interventions could have a positive impact, regardless of species of goat or parasite.publishedVersio

Goats in the city: prevalence of Giardia duodenalis and Cryptosporidium spp. in extensively reared goats in northern India

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Intestinal protozoan parasites in Northern India : investigations on transmission routes

Cryptosporidium and Giardia are protozoan parasites that have been confirmed as major causes of diarrhoea, particularly in children. They represent a significant, but often neglected, threat to public health, and particularly so in developing countries. They are able to cause widespread human and animal disease, and both protozoa contain species that are able to infect a wide range of host species, and are well-suited to cross the human ↔ animal boundaries. The robust transmission stages of both parasites, along with their high excretion rates and low infective dose, means that they can be transmitted through contamination of drinking water and fresh produce, as well as directly. Despite these facts, there are fewer reports on occurrences and outbreaks of cryptosporidiosis and giardiasis in developing countries, where there is no surveillance of contamination of the water supply, the fresh produce chain is not properly monitored, and animals roam with less restriction than in developed countries making the human ↔ animal boundaries fade. The reasons for this are many, and probably include diagnostic difficulties, lack of reporting, and an absence of investigation; it is unlikely to reflect that these infections occur more frequently in developed countries. This thesis consists of an experimental part and a survey part. The experimental part has a focus on affordable health, where expensive standard methods were modified and made accessible as cheaper options for analysis of fresh produce and drinking water for contamination with Cryptosporidium and Giardia. Also, the survival of infective stages of Giardia and Cryptosporidium on experimentally contaminated fresh produce was assessed; Giardia cysts were less capable of survival when stored at room temperature than refrigerated, whereas Cryptosporidium oocysts survived well both when refrigerated and at room temperature. This may partly explain the few documented foodborne outbreaks of giardiasis.Giardia og Cryptosporidium er parasittiske protozoer som har etablert seg som en av hovedårsakene til diarè hos mennesker, og da spesielt hos barn i utviklingsland. Der representerer de en signifikant, men ofte neglisjert, trussel for folkehelsen. De kan også forårsake utbredt sykdom hos dyr, og er velegnet til å krysse smittebarrierer mellom arter. På grunn av deres robuste overføringsstadier, høye ekskresjonsrate og lave infeksjonsdose, er disse parasittene svært effektive smittespredere og de kan overføres via kontaminerte drikkevannskilder og ferske råvarer, i tillegg til direkte smitte. Til tross for av at dette har vært lenge kjent, så er det færre rapporter om forekomster og utbrudd av kryptosporidiose og giardiose i utviklingsland, hvor hverken vannforsyning eller ferskvarekjeden overvåkes i samme grad som i utviklede land. I tillegg kan ofte dyr streife med mindre begrensninger enn i utviklede land, noe som resulterer i at smittebarrierene mellom mennesker og dyr blir mindre robuste. Årsakene til dette er mange og sammensatte, og sannsynligvis inkluderer de mangel på ressurser og utstyr til å utføre diagnostikk, manglende rapportering og mangel på overvåkning. I denne doktorgraden presenterer jeg en eksperimentell del og en deskriptiv del. Den eksperimentelle delen fokuserer på utvikling av rimeligere diagnostiske metoder, der kostbare standardiserte metoder ble modifisert og gjort tilgjengelige som billigere alternativer for analyse av ferske råvarer og drikkevann for påvisning av kontaminering med Cryptosporidium og Giardia. Overlevelsen av infektive stadier av Giardia og Cryptosporidium på eksperimentelt kontaminerte ferske råvarer ble også evaluert; Giardia-cyster hadde lavere viabilitet når de ble lagret ved romtemperatur enn kjølt, mens Cryptosporidiumoocystene overlevde både når de var kjølt og ved romtemperatur. Dette kan delvis forklare de få dokumenterte matbårne utbruddene av giardiose.submittedVersio

Characterizing parasitic nematode faunas in faeces and soil using DNA metabarcoding

Background Gastrointestinal parasitic nematodes can impact fecundity, development, behaviour, and survival in wild vertebrate populations. Conventional monitoring of gastrointestinal parasitic nematodes in wild populations involves morphological identification of eggs, larvae, and adults from faeces or intestinal samples. Adult worms are typically required for species-level identification, meaning intestinal material from dead animals is needed to characterize the nematode community with high taxonomic resolution. DNA metabarcoding of environmental samples is increasingly used for time- and cost-effective, high-throughput biodiversity monitoring of small-bodied organisms, including parasite communities. Here, we evaluate the potential of DNA metabarcoding of faeces and soil samples for non-invasive monitoring of gastrointestinal parasitic nematode communities in a wild ruminant population. Methods Faeces and intestines were collected from a population of wild reindeer, and soil was collected both from areas showing signs of animal congregation, as well as areas with no signs of animal activity. Gastrointestinal parasitic nematode faunas were characterized using traditional morphological methods that involve flotation and sedimentation steps to concentrate nematode biomass, as well as using DNA metabarcoding. DNA metabarcoding was conducted on bulk samples, in addition to samples having undergone sedimentation and flotation treatments. Results DNA metabarcoding and morphological approaches were largely congruent, recovering similar nematode faunas from all samples. However, metabarcoding provided higher-resolution taxonomic data than morphological identification in both faeces and soil samples. Although concentration of nematode biomass by sedimentation or flotation prior to DNA metabarcoding reduced non-target amplification and increased the diversity of sequence variants recovered from each sample, the pretreatments did not improve species detection rates in soil and faeces samples. Conclusions DNA metabarcoding of bulk faeces samples is a non-invasive, time- and cost-effective method for assessing parasitic nematode populations that provides data with comparable taxonomic resolution to morphological methods that depend on parasitological investigations of dead animals. The successful detection of parasitic gastrointestinal nematodes from soils demonstrates the utility of this approach for mapping distribution and occurrences of the free-living stages of gastrointestinal parasitic nematodes

Parasite contamination of berries: Risk, occurrence, and approaches for mitigation

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Occurrence of faecal endoparasites in reindeer (Rangifer tarandus) in two grazing areas in northern Norway

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Goats in the city: prevalence of Giardia duodenalis and Cryptosporidium spp. in extensively reared goats in northern India

Abstract Background Various characteristics of goats mean they are highly suitable livestock for backyard rearing by people with limited resources. They are a popular livestock choice in India, where they are often kept to supplement an already scarce income. In these settings, hygiene and sanitation standards tend to be low, and weakens the interface between humans and animals, thus reducing the barrier between them and thereby increasing the likelihood that zoonotic and anthroponotic infections will occur. Results This study reports an investigation of the occurrence of Cryptosporidium spp. and Giardia duodenalis in goats being reared in different settings in urban and peri-urban areas in northern India, and addressed the zoonotic potential of these important protozoan parasites shed from goats living close to humans. The overall prevalence of G. duodenalis was 33.8 and 0.5% for Cryptosporidium spp.; the relatively low prevalence of cryptosporidiosis may reflect that most samples were derived from adult animals. The prevalence of G. duodenalis excretion was found to be similar to that reported in other studies. However, although other studies have reported a predominance of non-zoonotic Assemblage E in goats, in this study potentially zoonotic Assemblages predominated [Assemblage A (36%) and Assemblage B (32%)]. Conclusions The results of this study indicate that in this area where goats and humans are living in close proximity, there may be sharing of intestinal parasites, which can be detrimental for both host species

Correction to: Goats in the city: prevalence of Giardia duodenalis and Cryptosporidium spp. in extensively reared goats in northern India

In the original publication of this article [1] the supplementary file was missing two primers for the PCR reaction and the PCR conditions of Giardia and Cryptosporidium. In this correction article the updated additional file (Additional file 1) is available, in which the two primers are included