Following the introduction of Anguillicola crassus into Lake Balaton, by 1991 the entire eel population became infected. At the same time, marked differences existed in the prevalence and intensity of infection between different areas of the lake. The highest prevalence values occurred in the eastern basin less densely populated with eels, while in the western basin a large proportion of the fish were free of infection. Helminth-free status accompanied by thickening of the swimbladder wall developed after intensive infections. In 1991, eel mortality could be observed only in the western basin. In 1992, the number of eels with swimbladders having a thickened wall but not containing helminths increased also in the central and eastern areas of the lake. Parallel to this, a mortality less expressed than the one in 1991 occurred in the central part of the lake. By 1993, a host-parasite equilibrium had become established in Lake Balaton.
Tsetse flies are well-known vectors of trypanosomes pathogenic for humans and livestock. For these strictly blood-feeding viviparous flies, the host blood should be the only source of nutrients and liquids, as well as any exogenous microorganisms colonising their intestine. Here we describe the unexpected finding of several monoxenous trypanosomatids in their gut. In a total of 564 individually examined Glossina (Austenia) tabaniformis (Westwood) (436 specimens) and Glossina (Nemorhina) fuscipes fuscipes (Newstead) (128 specimens) captured in the Dzanga-Sangha Protected Areas, Central African Republic, 24 (4.3%) individuals were infected with monoxenous trypanosomatids belonging to the genera Crithidia Léger, 1902; Kentomonas Votýpka, Yurchenko, Kostygov et Lukeš, 2014; Novymonas Kostygov et Yurchenko, 2020; Obscuromonas Votýpka et Lukeš, 2021; and Wallacemonas Kostygov et Yurchenko, 2014. Moreover, additional 20 (3.5%) inspected tsetse flies harboured free-living bodonids affiliated with the genera Dimastigella Sandon, 1928; Neobodo Vickerman, 2004; Parabodo Skuja, 1939; and Rhynchomonas Klebs, 1892. In the context of the recently described feeding behaviour of these dipterans, we propose that they become infected while taking sugar meals and water, providing indirect evidence that blood is not their only source of food and liquids.
Liver pathologies and infection with Toxoplasma gondii (Nicolle et Manceaux, 1908) are widespread among HIV-infected patients. However, a possible contribution of toxoplasmosis to the development of various forms of liver diseases in HIV-infected individuals has not yet been determined. This research is a retrospective cohort study. Medical cards of 907 HIV-positive patients, including 119 individuals who died, were studied. The patients were divided into two groups: 531 patients were seropositive to T. gondii and 376 seronegative. General liver pathology was more widespread among patients seropositive to T. gondii than in seronegative patients (63.1 ± 2.1% and 51.9 ± 2.6%, respectively, p < 0.001). The association of seropositive to T. gondii with general liver pathology is weak both in the whole cohort (Pearson's contingency coefficient C = 0.112), and among the deceased patients (C = 0.228). and Chronic HBV-HCV coinfection was more common in the seropositive than in seronegative individuals as it was found both in entire cohorts (26.0 ± 1.9% and 18.6 ± 2.0%, respectively, p = 0.010) and in died patients (31.0 ± 5.5% and 14.6 ± 5.1%, respectively, p = 0.041). Toxoplasma gondii had a weak role in distributing of HBV-HCV coinfection between cohorts (C = 0.187). In both cohorts in patients with chronic hepatitis, regardless of its etiology, there was no significant difference in alanine transaminase activity (ALT). Cirrhosis of the liver occurred 4.5 times more often in deceased seropositive patients than in the entire seropositive cohort (23.9 ± 5.1 and 5.3 ± 2.0, respectively, p = 0.0006) whereas it no significantly increased in seronegative cohort (10.4 ± 4.4 against 4.8 ± 1.1, p > 0.05). In them T. gondii is weakly involved in cirrhosis formation (C = 0.168). Thus, in HIV-infected patients, T. gondii is a weak nonspecific adjunct that supports chronic liver inflammation and progression of cirrhosis, regardless of etiology, but does not influence the degree of hepatitis activity. The increased prevalence of HBV-HCV coinfection in patients seropositive for T. gondii may be related to their risk factor behaviour associated with uncontrolled blood contacts.
One of four Hoplobatrachus occipitalis (Günther, 1859) frogs received from Niger, West Africa was heavily infected with Lankesterella blood and pre-erythrocytic stages. Infected blood and tissues from this frog were force-fed to the remaining three frogs. Two survived to necropsy on days 14 and 27 post-feeding and were found to be infected with gamogonic and oogonic stages, respectively. The source of infection is inconclusive, as a natural origin cannot be excluded. Microgamont, macrogamont, oocyst and sporozoite structure and fine structure are described and found to conform in general, but not in detail, to previous descriptions. Gamonts and oocysts occurred predominantly in the liver and spleen. Walled sporulating oocysts were situated within macrophage centres. Oocysts yielded a progeny of 32 sporozoites. Pre-erythrocytic sporozoites developed within expanded inclusions, within their host cell, from which they massively invaded the liver and spleen, and to a lesser extent the lungs and kidneys. Sporozoites occurred in a parasitophorous vacuole in the erythrocytes. Conspecificity with Lankesterella dicroglossi Paperna et Ogara, 1996 reported from the same host species in Kenya remains uncertain due to several structural and developmental differences.