Human Toxocariasis in Portugal-An Overview of a Neglected Zoonosis over the Last Decade (2010-2020).

Toxocariasis is one of the most widespread and important zoonotic parasitic diseases, although neglected. Data regarding human Toxocara infection in Portugal are almost absent. This article gives an overview of the situation of toxocariasis in Portugal over the last decade based on casuistic data. A total of 846 serum samples from individuals suspected of toxocariasis, collected from 2010 to 2020, were analyzed at the Institute of Hygiene and Tropical Medicine. Sera were tested for IgG antibodies to Toxocara canis excreted-secreted larval antigens by enzyme-linked immunosorbent assay and counterimmunoelectrophoresis. Positivity was detected in 18.8% (159/846) [CI 95%: 16.3-21.6], with positives detected throughout continental Portugal. Overall, 59.7% of the positives were diagnosed in younger than 20 years (35.2% aged 0-9 years and 24.5% aged 10-19 years). Eosinophilia was the most frequent feature reported (27.7%). Pediatrics (41.5%) and Infectiology (25.8%) were the specialties with the highest number of positives. An average of 77 samples/year were received, recording a maximum positivity in 2012 (41.5%, n = 27/65) and a minimum in 2020 (6.4%, n = 3/47). These numbers may reflect the effectiveness of current preventive measures, highlighting the need to maintain public awareness to control this helminthozoonosis and promote a higher public health standard.

Plague: A Millenary Infectious Disease Reemerging in the XXI Century.

Plague, in the Middle Ages known as Black Death, continues to occur at permanent foci in many countries, in Africa, Asia, South America, and even the USA. During the last years outbreaks were reported from at least 3 geographical areas, in all cases after tens of years without reported cases. The recent human plague outbreaks in Libya and Algeria suggest that climatic and other environmental changes in Northern Africa may be favourable for Y. pestis epidemiologic cycle. If so, other Northern Africa countries with plague foci also may be at risk for outbreaks in the near future. It is important to remember that the danger of plague reoccurrence is not limited to the known natural foci, for example, those of Algeria, Angola, and Madagascar. In a general context, it is important that governments know the dangerous impact that this disease may have and that the health and medical community be familiar with the epidemiology, symptoms, treatment, and control of plague, so an appropriated and timely response can be delivered should the worst case happen. Plague can be used as a potential agent of bioterrorism. We have concluded that plague is without a doubt a reemerging infectious disease.

Onchocerciasis caused by Onchocerca lupi: an emerging zoonotic infection. Systematic review.

Globalization has increased circulation of people, their food, livestock and pets in the world, and changes in the environment, climate and human behaviour have led to the rapid expansion of emerging infections throughout the world. One of the reasons of a new pathogen affecting humans is the passage from an animal to a human being. Onchocerca (O.) lupi, a filarial worm first described in a wolf in 1967, is an emerging pathogen which has been incriminated as the etiological agent for 205 canine, 2 feline and 18 human infections in Europe, Tunisia, Turkey, Iran and the USA. Most frequent findings in animals and humans are monolateral or asymmetrical variably painful subconjunctival swellings and nodules containing immature or mature worms affecting the eye and/or adjacent tissues accompanied by conjunctival hyperemia. Occasionally, subcutaneous nodules and masses affecting the spinal cord have been observed in humans. Diagnosis of O. lupi is achieved by microscopy of excised adult female worms which exhibit a particular cuticular structure and molecular analysis. Treatment consists in worm removal accompanied by antihelminthic, antibiotic and anti-inflammatory therapy.

A case of imported neurocysticercosis in Portugal.

Neurocysticercosis (NCC) is the most common cause of acquired epilepsy in resource-poor countries. We report the case of a 24-year-old woman born and residing in Guinea-Bissau, who was transferred to Portugal two months after the onset of a possible meningitis (fever, headache, seizures, and coma) that did not respond to antibiotic treatment. The diagnosis of NCC was confirmed by MR imaging, which showed multiple lesions compatible with cysticercus, and by polymerase chain reaction (PCR) of the cerebrospinal fluid. After 28 days on albendazole and dexamethasone without improvement, she was started on praziquantel, which she completed in six weeks with progressive recovery.

Prostate adenocarcinoma associated with prostatic infection due to Schistosoma haematobium. Case report and systematic review.

Schistosomiasis affects more than 240 million people worldwide, an infection which may cause urogenital manifestations including, among others, squamous bladder cancer and prostate involvement. We describe the first case of a prostate adenocarcinoma associated with prostatic Schistosoma haematobium infection occurring in Angola. Prostate carcinoma was suspected because of high levels of prostate-specific antigen. This observation prompted us to review the literature on schistosomiaisis with respect to genital pathology and prostate cancer. Described genital manifestations in men include funiculitis, epididymitis, granulomata of the seminal vesicles, testicular masses, and prostate lesions which may cause haematospermia and infertility. In contrast to bladder cancer, only 12 reports including the present case on 17 cases on prostate carcinoma associated with schistosomiasis have been published worldwide. The rarity of reports on prostate carcinoma associated with schistosomiasis is partly due to diagnostic constraints, and its incidence is underestimated. However, in emerging countries, the incidence of prostate cancer appears to increase mainly as a result of urbanization and improved access to health care where schistosomiasis prevalence is decreasing.

[Schistosomiasis and acute appendicitis]. / Schistosomose e apendicite aguda.

Acute appendicitis associated to Schistosoma haematobium and S. mansoni infection has been found in patients submitted to urgent appendectomy at the Hospital Américo Boavida in Luanda. Due to the high prevalence and morbidity caused by schistosomiasis (or bilharziasis) in the country, we suspect that the involvement of Schistosoma infection on appendicular pathology could be very frequent, in particular for those individuals more exposed to the parasite transmission. We report two clinical cases of acute appendicitis whose surgical specimens of the appendix revealed S. haematobium and S. mansoni eggs in histological samples. The reported patients live in endemic areas and have been exposed to schistosome during childhood, which may explain the infection's chronicity. Information of these clinical cases could be relevant, particularly for surgery specialists and clinical pathologists, due to the possibility of finding more patients with concurrent appendicitis and schistosomiasis.

A ocorrência de casos de apendicite aguda causada por Schistosoma haematobium e S. mansoni é uma situação clínica que tem vindo a ser observada em doentes submetidos a apendicectomia na urgência do Hospital Américo Boavida em Luanda. Atendendo à prevalência e morbilidade da schistosomose (ou bilharziose) no país, admitimos que esta infeção parasitária seja um fator causal muito frequente de apendicite, particularmente nas populações mais expostas à transmissão. Descrevemos dois casos de apendicite aguda associada à presença de ovos destas espécies de Schistosoma atingindo a mucosa do apêndice visíveis por histologia, em doentes naturais de zonas endémicas de Angola, com exposição precoce aos parasitas, o que justifica a cronicidade da infeção. Consideramos que a divulgação destes casos será particularmente relevante para as equipas de cirurgia geral e de anatomopatologia, atendendo à necessidade de execução sistemática de exames histológicos em todas as peças operatórias relacionadas.

Echinococcus granulosus in Portugal: the first report of the G7 genotype in cattle.

Although cystic echinococcosis (CE) has been a recognized public health problem in Portugal, molecular data regarding the types and prevalence of infecting strains of its etiological agent (Echinococcus granulosus) are still scarce. Over the last years we have been evaluating the prevalence of CE in the country, and in this report we determined the parasite genotypes infecting sheep, goats, cattle and human in Portugal, based on 209 hydatid cysts recovered from liver (n=96), lung (n=95), pancreas (n=17) and kidney (n=1) samples obtained between 2008 and 2011. Protoscoleces or germinal layers were collected from individual cysts, DNA was extracted, and a part of the mitochondrial DNA encoding the cytochrome c oxidase subunit 1 was amplified by PCR. Overall, the results confirm the overall dominance of the G1-G3 cluster of strains, which are particularly prevalent in southern Portugal in livestock ruminants. Unexpectedly, one parasite sequence with cattle origin was found to correspond to E. granulosus G7 genotype (also known as E. intermedius), here reported for the first time in bovine, in Portugal.

Apparent dominance of the G1-G3 genetic cluster of Echinococcus granulosus strains in the central inland region of Portugal.

Infection by the larval stage of the cestode Echinococcus granulosus causes a disease known as cystic echinococcosis or hydatidosis, which is one of the most widespread zoonotic infections of veterinary and medical importance. Numerous studies have shown that E. granulosus exists as a complex of strains differing in a wide variety of criteria. Ten distinct genotypes (G1-G10) have been identified with a potential impact on the pathology, epidemiology and the effect of the measures implemented for the control of hydatidosis. Our main objective was to carry out a preliminary analysis of the genotypes of E. granulosus circulating in the central inland region of Portugal. Parasite samples (hydatid cysts, n=27) were isolated from the liver and lung of sheep and cattle. The DNA extracted from protoscoleces isolated from the fertile cysts served as a template for the PCR amplification of the part of the mitochondrial cytochrome c oxidase subunit 1 (cox1), ATP synthase F0 subunit 6 (atp6) as well as the large (rrnL/16S) and small (rrnS/12S) ribosomal RNA genes. Similarity searches with homologous sequences in the databanks indicated a very high similarity with references assigned to the G1, G3 and/or G1-G3 complex of Echinococcus strains. Phylogenetic analysis (Bayesian approach) supported these observations, and confirmed the assignment of all the analyzed sequences to the G1-G3 genetic cluster.

Toxocara canis: potential activity of natural products against second-stage larvae in vitro and in vivo.

The anthelmintic activity of extracts from Chenopodiumambrosioides, Pycnanthusangolensis and Nutridesintox was in vitro and in vivo investigated, against Toxocaracanis larvae. The in vitro assays results showed that the aqueous extract of Nutridesintox was the most effective, followed by C. ambrosioides extracts, hexane, dichloromethane and the infusion. P. angolensis extracts showed a lower anthelmintic activity compared to the other natural products. For the in vivo assays, Nutridesintox, the hexane extract and the infusion of C. ambrosioides were administered orally to T. canis-infected mice, in single doses, during three consecutive days. The efficacy was evaluated on the 17th day post-infection, not only by counting T. canis larvae in the tissues but also by ELISA detection of IgM and IgG antibodies and histological analysis of liver and lungs. The different treatments did not reduce the larvae burden and had no influence on the antibodies dynamic. Interestingly, a reduction on the inflammatory infiltrates was observed in the liver and lung sections of the group treated with the hexane extract of C. ambrosioides. In conclusion, the hexane extract of C. ambrosioides is of further research interest, as it showed an anthelmintic activity in vitro and a reduction on the inflammatory reaction produced by the infection of T. canis larvae in vivo.

Since phenothiazines alter antibiotic susceptibility of microorganisms by inhibiting efflux pumps, are these agents useful for evaluating similar pumps in phenothiazine-sensitive parasites?

Phenothiazines have activity against Schistosoma mansoni, Trypanosoma brucei, Trypanasoma gambiensi, Molinema dessetae, Leishmania spp., Plasmodium falciparum and free-living protozoa. These organisms and other parasitic infections are prevalent in HIV-infected humans. These infections are becoming more frequently resistant to commonly employed antibiotics, and due to the absence of economic motivation, new and effective compounds against these infections are not anticipated in the near future. Resistance of prokaryotes and eukaryotes to antibiotics is now known to be also due to the presence of efflux pumps that extrude the antibiotic prior to the agent reaching its target. Because phenothiazines are known to inhibit some efflux pumps and therefore alter the susceptibility of the organism to an antibiotic to which it is resistant, and also because of the sensitivity of the above parasites to phenothiazines, efflux pumps may play a role in emerging antibiotic resistance of these organisms. Furthermore, their prevalence is known to be greatest in areas that have high rates of HIV infection; therefore, it would be necessary that these agents should receive close scrutiny. This review concerns the attributes afforded by phenothiazines related to their effective activity against a wide range of parasites. Because these agents are inexpensive and many are no longer protected by patent, they may be exploited as anti-parasitic agents in the poorer areas of the world.

Carpobrotus edulis methanol extract inhibits the MDR efflux pumps, enhances killing of phagocytosed S. aureus and promotes immune modulation.

Although alkaloids from the family Aizoaceae have anticancer activity, species of this family have received little attention. Because these alkaloids also exhibit properties normally associated with compounds that have activity at the level of the plasma membrane, a methanol extract of Carpobrotus edulis, a common plant found along the Portuguese coast, was studied for properties normally associated with plasma membrane active compounds. The results of this study show that the extract is non-toxic at concentrations that inhibit a verapamil sensitive efflux pump of L5178 mouse T cell lymphoma cell line thereby rendering these multi-drug resistant cells susceptible to anticancer drugs. These non-toxic concentrations also prime THP-1 human monocyte-derived macrophages to kill ingested Staphylococcus aureus and to promote the release of lymphokines associated with cellular immune functions. The extract also induces the proliferation of THP-1 cells within 1 day of exposure to quantities normally associated with phytohaemagglutinin. The potential role of the compound(s) isolated from this plant in cancer biology is intriguing and is currently under investigation. It is supposed that the resistance modifier and immunomodulatory effect of this plant extract can be exploited in the experimental chemotherapy of cancer and bacterial or viral infections.