Helminth infection is highly prevalent in indigenous chickens reared in semi-scavenging/ scavenging systems in Bangladesh. Here, we estimated the prevalence of gizzard worm infection in indigenous chickens, the detection of the worm-induced pathologies, the development of ex vivo cultural protocol, and anthelmintic efficacy. We randomly collected and examined 390 chickens and isolated worms from the gizzard and proventriculus. The isolated worms were identified as Cheilospirura hamulosa Diesing, 1861. The overall prevalence of C. hamulosa was 33.1% (129 out of 390). Prevalence of the worm was almost similar in both sexes but significantly (p <0.05) higher in adult chickens (44.3%) and in the summer season (47.1%). In heavy infections, C. hamulosa destroyed the muscular layer of the gizzard. The presence of brown necrotic tissues and curd-like caseous materials was detected in the affected gizzards. In severe cases, the horny lining of the gizzard was inflamed, necrotized and marked by multiple holes and brick-red colored spots. Liquefied, fetid materials oozed out from the muscular layer in extensive cases. Histopathological examination showed marked infiltrations of eosinophils. In serum-supplemented M199 and DMEM, adult C. hamulosa survived well and reproduced. Levamisole (LEV) and ivermectin (IVM) efficiently killed the worm. However, albendazole (ABZ), mebendazole (MBZ) and piperazine (PPZ) did not kill the worms. Our results suggest that C. hamulosa is highly prevalent in semi-scavenging chickens in Bangladesh. LEV and IVM can be used to treat and control the infection in chickens.

The impact of macroparasites on their hosts is proportional to the number of parasites per host, or parasite abundance. Abundance values are count data, i.e. integers ranging from 0 to some maximum number, depending on the host–parasite system. When using parasite abundance as a predictor in statistical analysis, a common approach is to bin values, i.e. group hosts into infection categories based on abundance, and test for differences in some response variable (e.g. a host trait) among these categories. There are well-documented pitfalls associated with this approach. Here, I use a literature review to show that binning abundance values for analysis has been used in one-third of studies published in parasitological journals over the past 15 years, and half of the studies in ecological and behavioural journals, often without any justification. Binning abundance data into arbitrary categories has been much more common among studies using experimental infections than among those using naturally infected hosts. I then use simulated data to demonstrate that true and significant relationships between parasite abundance and host traits can be missed when abundance values are binned for analysis, and vice versa that when there is no underlying relationship between abundance and host traits, analysis of binned data can create a spurious one. This holds regardless of the prevalence of infection or the level of parasite aggregation in a host sample. These findings argue strongly for the practice of binning abundance data as a predictor variable to be abandoned in favour of more appropriate analytical approaches.

Anaplasmosis is a significant tick-borne disease (TBDs) caused by Anaplasma that affecting ruminant health and production worldwide. This study aimed to identify Anaplasma spp. infection using molecular as a fast diagnostic tool, perform a phylogenetic analysis and evaluate associated risk factors for combating Anaplasma spp. infection in small-scale livestock farms in Thailand. Total 963 blood samples from ruminants were collected from 125 farms across 4 regions of Thailand. Molecular diagnosis of Anaplasma spp. targeted the msp4 gene using conventional polymerase chain reaction (PCR) was performed and reported to the farmers within 14 days. Positive PCR products were purified, sequenced, and analysed the phylogenetic. Associated risk factor evaluations were conducted using R software. The overall prevalence of Anaplasma spp. infection in ruminants was 26.90%. The highest prevalence was observed in bullfighting cattle (47.06%), followed by beef cattle (35.75%), dairy cattle (21.73%), and goats (6.67%), with no infection in buffalo. Regionally, the Northern region had the highest prevalence (49.01%), followed by the Southern (25.88%), Central (22.01%), and Northeastern (13.81%) regions. Anaplasma spp. was commonly detected in Phrae, Chiang Rai, and Tak provinces. Sequencing confirmed A. marginale 99.64% to 99.76% identity to sequences in GenBank. Risk factors associated with A. marginale infection were history of TBDs on farm, animal illnesses, responsible person for treatment, and improper faeces removal practices. This study revealed a moderate to high Anaplasma infection across four regions. These findings underscore the need for enhanced tick control measures on farms, should be strictly implemented and promoted to reduce disease prevalence.

It is often postulated that natural systems are expected to suffer an increasing risk of infectious disease outbreaks as climate change accelerates. In the northern Argentine Sea, the rise of ocean temperature has produced a tropicalization of demersal megafauna since 2013. This rapidly warming hotspot provides an excellent model to test whether fish parasites have increased, declined, or remained stable in the region. Cardiocephaloides physalis a parasite of penguins Spheniscus magellanicus as adult and suspected to parasitize anchovies Engraulis anchoita as larvae is here used to compare their occurrence and abundance between samples composed by 1752 fish of variable age caught at different latitudes during 1993–1995 and 2022 and between 20 juvenile birds and literature data. In the present work, the identity of metacercariae as C. physalis is confirmed genetically, as well as a net decline of population parameters of the parasite to its effective disappearance in anchovies from northern areas and to extremely low levels in fish from southern regions and penguins. After analysing possible causes for such changes in a scenario of rapid regional tropicalization, a direct effect of increasing temperature on parasites arose as the main causal candidate for the observed decline in their populations over the last decades. Beyond the biological and ecological consequences of global change on them, parasites offer excellent systems for measuring and monitoring such effects. The almost local extinction of C. physalis in a marine hotspot of global warming seems to be one of the first examples of such processes.

We present four cases of male genital schistosomiasis (MGS) within children and adolescents opportunistically encountered as part of a wider screening programme for imported schistosomiasis in Germany and community outreach screening in Mali. Such genital manifestations in young children and adolescents are often overlooked but can include hydrocele, hypogonadism, varicocele, cutaneous granulomata on the penis and scrotum, echogenic spots in the prostate and the epididymis, alongside testicular masses. Though these cases appear sporadic, from our scoping literature review, they draw fresh attention on MGS in young children and highlight wider confusion with other congenital, neoplastic and infectious disease. These might include an insufficient closure of the tunica vaginalis, malignancies or lymphatic filariasis. Frequently haematuria is not present. One typical sign indicating MGS in adults, i.e. haematospermia is not present before puberty. Another reason of missing MGS cases may be that screening with scrotal or transabdominal ultrasonography are not easily accepted unless the reason for it is not extensively explained beforehand and that transabdominal ultrasonography is less sensitive for revealing prostatic lesions than transrectal ultrasonography.

The presence of parasites can elicit host responses even in the absence of infection. These risk-induced trait responses include altered host behaviours, morphology, and/or physiology, which can trade off with other fitness-related traits. Studies of predator-induced non-consumptive effects (NCEs) have demonstrated that exposure at one life stage can lead to NCEs in the next stage, but no studies to date have examined such an effect of parasite exposure. Numerous NCEs have been demonstrated in larval, pupal and adult stages of Drosophila nigrospiracula exposed to ectoparasitic mites (Macrocheles subbadius). Here we experimentally investigated whether parasite-induced NCEs carry over into subsequent developmental stages (i.e. interstadial effects). We tested the prediction that when flies are exposed to mites during the larval and pupal stages, the subsequent adult stage will exhibit decreased body mass, fecundity and longevity. However, we did not detect downstream effects of parasite exposure on adult body mass, fecundity or longevity. The probability of survival and lifetime fecundity were comparable for previously exposed and unexposed groups. We suggest that when parasite exposure is confined to one developmental stage, and the risk of infection is removed in the subsequent stage, the long-term effects of parasite exposure dissipate. The potential to recover from the interim costs of parasite exposure may provide an added benefit to host dispersal.

The objective of this study was to assess the potential role of aquatic biofilms as natural reservoirs for Blastocystis. For this purpose, surface water (n = 4) and biofilm samples (n = 8) were collected from a stream nearby an urban area characterized by limited sanitation infrastructure and a high prevalence of Blastocystis in humans. Blastocystis cysts were detected in three of the four water samples and seven of the eight biofilm samples using fluorescence microscopy. Furthermore, viable cysts were identified exclusively in biofilm samples (five of the eight), while no live cysts were detected in water samples. These findings indicate that aquatic biofilms provide a habitat where Blastocystis cysts can adhere and remain viable, potentially contributing to their environmental accumulation. In addition, molecular characterization of the five isolates identified subtypes ST8 (allele 21) and ST3 (allele 36). This study is the first to report the detection and identification of viable Blastocystis subtypes in aquatic biofilms. The analysis of biofilms by fluorescence microscopy, as demonstrated here, offers a promising approach for monitoring Blastocystis and could serve as an alternative to traditional water sampling methods.

Aplectana membranosa is a cosmocercid nematode that shows affinity with various amphibian and reptile hosts, being considered a generalist species. To date, no studies have investigated the influence of host and locality in the morphological variation of this species. Thus, we analysed morphological and morphometric characters of 260 specimens of A. membranosa collected from 9 host species and 7 different localities. To complement the metric studies, we conducted phylogenetic analyses using the ribosomal genes 28S and internal transcript spacer 1 (ITS1) to determine the phylogenetic position of the species and its divergence. In the present study, it was possible to observe the cloacal papillae pattern of the species through scanning electron microscopy, and we found no morphological variation in the specimens of A. membranosa from various hosts in different localities in Brazil. The study showed low variation in all data. However, despite the low variation, we found that external environmental conditions, such as climate and latitude, influence its variation. Molecular analyses highlighted that the separation of Cosmocercidae members may be related to geographic distribution and population genetic divergence. Thus, the results illustrated in this study reiterate the importance of using integrative data to better elucidate the family’s taxonomic and evolutionary history.

Birds possess the most diverse assemblage of haemosporidian parasites, although the true diversity is unknown due to high genetic diversity and insufficient sampling across all avian clades. Waterfowl (Order Anseriformes) are an ideal group to discover hidden parasite diversity and examine the role of host ecology in parasite transmission. Waterfowl contain 2 distinct feeding guilds, dabbling and diving, which differ in niche utilization that likely alters vector encounter rates and haemosporidian parasite risk. To determine the role of feeding guild in haemosporidian parasitism we analysed 223 blood samples collected by hunters from the upper Midwest of the United States from 2017 to 2019. Fifty-four individuals were infected by haemosporidian parasites (24·2% prevalence). Infection prevalence differed significantly between dabbling (34·9%, n = 109) and diving (14·0%, n = 114) ducks. Feeding guild was the only host trait that could predict haemosporidian infection risk, with a significantly higher risk in dabbling ducks. Twenty-four haemosporidian lineages were identified, with 9 identified for the first time. Thirteen lineages were found only in dabbling ducks, 5 only in diving ducks and 6 in both feeding guilds. Community analysis showed that each feeding guild harboured a unique parasite community. There was no phylogenetic signal of feeding guild within a phylogenetic reconstruction of North American waterfowl haemosporidian lineages. Our results demonstrate that waterfowl contain a diverse and distinct community of haemosporidian parasites. The unique composition of each feeding guild determines not only haemosporidian infection risk but also community structure. This is the first report of such an impact for waterfowl feeding guilds.