The Database of European Forest Insect and Disease Disturbances: DEFID2.

Insect and disease outbreaks in forests are biotic disturbances that can profoundly alter ecosystem dynamics. In many parts of the world, these disturbance regimes are intensifying as the climate changes and shifts the distribution of species and biomes. As a result, key forest ecosystem services, such as carbon sequestration, regulation of water flows, wood production, protection of soils, and the conservation of biodiversity, could be increasingly compromised. Despite the relevance of these detrimental effects, there are currently no spatially detailed databases that record insect and disease disturbances on forests at the pan-European scale. Here, we present the new Database of European Forest Insect and Disease Disturbances (DEFID2). It comprises over 650,000 harmonized georeferenced records, mapped as polygons or points, of insects and disease disturbances that occurred between 1963 and 2021 in European forests. The records currently span eight different countries and were acquired through diverse methods (e.g., ground surveys, remote sensing techniques). The records in DEFID2 are described by a set of qualitative attributes, including severity and patterns of damage symptoms, agents, host tree species, climate-driven trigger factors, silvicultural practices, and eventual sanitary interventions. They are further complemented with a satellite-based quantitative characterization of the affected forest areas based on Landsat Normalized Burn Ratio time series, and damage metrics derived from them using the LandTrendr spectral-temporal segmentation algorithm (including onset, duration, magnitude, and rate of the disturbance), and possible interactions with windthrow and wildfire events. The DEFID2 database is a novel resource for many large-scale applications dealing with biotic disturbances. It offers a unique contribution to design networks of experiments, improve our understanding of ecological processes underlying biotic forest disturbances, monitor their dynamics, and enhance their representation in land-climate models. Further data sharing is encouraged to extend and improve the DEFID2 database continuously. The database is freely available at https://jeodpp.jrc.ec.europa.eu/ftp/jrc-opendata/FOREST/DISTURBANCES/DEFID2/.

Effectiveness of field-exposed attract-and-kill devices against the adults of Popillia japonica (Coleoptera: Scarabaeidae): a study on duration, form and storage.

BACKGROUND: The Japanese beetle Popillia japonica Newman is an insect pest native to Japan that has spread into North America, the Azores and, recently, into continental Europe. Here, we present a study assessing the effectiveness of a long-lasting insecticide-treated net (LLIN), assembled in semiochemical-baited attract-and-kill devices (A&Ks) as a low environmental impact means to control P. japonica in the field. We compared the attractiveness of three different forms of A&Ks that were left outdoors throughout the summer, and the residence time of P. japonica landing on them. Moreover, we performed a preliminary study testing the effectiveness of new LLINs after storage. Collected data also allowed us to investigate the beetles' diel flight patterns in relation to meteorological conditions. RESULTS: Killing effectiveness of the field-exposed A&Ks declined steadily over the flight season (from 100% to 37.5%) associated with a decrease in residues of α-cypermethrin, the active ingredient in the LLINs. The different A&K forms (pyramidal, octahedral and ellipsoidal) attracted similar numbers of beetles. Individual beetles' residence time ranged from 75 to 95 s and differed slightly between A&K forms. Effectiveness of LLINs decreased by ≈30% after 1 year storage. Based on numbers landing on A&Ks, the beetles' flight activity peaked about 14:30 h and was inversely correlated with relative humidity. CONCLUSION: This study indicates that semiochemical-baited A&Ks are effective for controlling P. japonica in the field. Because of active ingredient decay, the LLINs should be replaced after 30-40 days of field exposure to ensure that the A&Ks remain fully functional. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Genetic variability of Metarhizium isolates from the Ticino Valley Natural Park (Northern Italy) as a possible microbiological resource for the management of Popillia japonica.

The natural occurrence of entomopathogenic fungi (EPF) was investigated along the Ticino River (Ticino River Natural Park, Novara Province, Piedmont, Italy), at the center of the area of the first settlement of the invasive alien pest Popillia japonica. Using Zimmermann's "Galleria bait method", EPF were successfully isolated from 83 out of 155 soil samples from different habitats (perennial, cultivated, or uncultivated meadows, woodlands, and riverbanks). Sequencing of the 5' end of the Translation Elongation Factor 1 alfa (5'-TEF) region allowed the assignment of 94% of the isolates to Metarhizium spp., while 8% and 7% were assigned to Beauveria spp. and Paecilomyces spp., respectively. Four Metarhizium species were identified: Metarhizium robertsii was the most common one (61.5% of the isolates), followed by M. brunneum (24.4%), M. lepidiotae (9%), and M. guizhouense (5.1%). Microsatellite marker analysis of the Metarhizium isolates revealed the presence of 27 different genotypes, i.e., 10 genotypes among M. robertsii, 8 among M. brunneum, 5 among M. lepidiotae, and 4 among M. guizhouense. Metarhizium brunneum appeared to be associated with woodlands and more acid soils, while the other species showed no clear association with a particular habitat. Laboratory virulence tests against P. japonica 3rd instar larvae allowed the identification of one M. robertsii isolate that showed efficacy as high as 80.3%. The importance of this kind of study in the frame of eco-friendly microbiological control is discussed.

Popillia japonica - Italian outbreak management.

Popillia japonica, a priority pest for the EU, was first detected in Northern Italy in 2014. Since its discovery, the outbreak extended over an area of more than 16,000 square kilometers in Northern Italy and Southern Switzerland. In this review, we summarize the state-of-the-art of research conducted in Italy on both the spreading capacity and control measures of P. japonica. Chemical, physical, and biological control measures deployed since its detection are presented, by highlighting their strengths and weaknesses. An in-depth study of the ecosystems invaded by P. japonica disclosed the presence and pathogenicity of natural strains of entomopathogenic fungi and nematodes, some of which have shown to be particularly aggressive towards the larvae of this pest under laboratory conditions. The Plant Health authorities of the Lombardy and Piedmont regions, with the support of several research institutions, played a crucial role in the initial eradication attempt and subsequently in containing the spread of P. japonica. Control measures were performed in the infested area to suppress adult populations of P. japonica by installing several traps (e.g., for mass trapping, for auto-dissemination of the fungus Metarhizium anisopliae, and "attract & kill"). For larval control, the infested fields were treated with commercial strains of the entomopathogenic fungus M. anisopliae and nematode Heterorhabditis bacteriophora. Future studies will aim at integrating phenological and spread models developed with the most effective control measures, within an ecologically sustainable approach.

Assessing the Distribution of Exotic Egg Parasitoids of Halyomorpha halys in Europe with a Large-Scale Monitoring Program.

The brown marmorated stink bug Halyomorpha halys is an invasive agricultural pest with a worldwide distribution. Classical biological control has been identified as the most promising method to reduce the populations of H. halys. Adventive populations of two candidates for releases, Trissolcus japonicus and Trissolcus mitsukurii, have recently been detected in Europe. To assess their distribution and abundance, a large-scale survey was performed. From May to September 2019, a wide area covering northern Italy and parts of Switzerland was surveyed, highlighting the expanding distribution of both Tr. japonicus and Tr. mitsukurii. Within four years after their first detection in Europe, both species have rapidly spread into all types of habitats where H. halys is present, showing a wide distribution and continuous expansion. Both exotic Trissolcus showed high levels of parasitism rate towards H. halys, while parasitization of non-target species was a rare event. The generalist Anastatus bifasciatus was the predominant native parasitoid of H. halys, while the emergence of native scelionids from H. halys eggs was rarely observed. The presence of the hyperparasitoid Acroclisoides sinicus was also recorded. This study provided fundamental data that supported the development of the first inoculative release program of Tr. japonicus in Europe.

Rearing Trissolcus japonicus and Trissolcus mitsukurii for Biological Control of Halyomorpha halys.

Halyomorpha halys is a severe agricultural pest of Asian origin that has invaded many countries throughout the world. Pesticides are currently the favored control methods, but as a consequence of their frequent use, often disrupt Integrated Pest Management. Biological control with egg parasitoids is seen as the most promising control method over the long-term. Knowledge of the reproductive biology under laboratory conditions of the most effective candidates (Trissolcus japonicus and Trissolcus mitsukurii) for optimizing production for field releases is strongly needed. Rearing of these egg parasitoids was tested by offering three different host supply regimes using new emerged females and aged, host-deprived females in different combinations. Results showed a mean progeny per female ranging from 80 to 85 specimens for T. japonicus and from 63 to 83 for T. mitsukurii. Sex ratios were strongly female biased in all combinations and emergence rates exceeded 94% overall. Cumulative curves showed that longer parasitization periods beyond 10-14 days (under the adopted rearing regimes) will not lead to a significantly increase in progeny production. However, ageing females accumulate eggs in their ovaries that can be quickly laid if a sufficient number of host eggs are supplied, thus optimizing host resources. Our data showed that offering H. halys egg masses to host-deprived female Trissolcus once a week for three weeks allowed its eggs to accumulate in the ovary, providing the greatest number of offspring within a three week span.

Evaluation of Indigenous Entomopathogenic Nematodes as Potential Biocontrol Agents against Popillia japonica (Coleoptera: Scarabaeidae) in Northern Italy.

The natural presence of entomopathogenic nematodes (EPNs) has been investigated in the Piedmont region (Northern Italy) in areas infested by the Japanese beetle Popillia japonica. Thirty-nine out of 155 soil samples (25.2%) were positive for EPNs. Most of the samples contained only steinermatids (92.3%), 5.1% contained heterorhabditids, and one sample (2.6%) contained both genera. All the recovered isolates were identified at species level both morphologically and molecularly. Steinernema carpocapsae was the most abundant and it was mainly distributed in open habitats, such as perennial meadows, uncultivated soils, and cropland, characterized by sandy loam soil texture and acidic pH. Steinernema feltiae has been found associated mainly with closed habitats such as coniferous and deciduous woodland, characterized by sandy loam-texture and extremely acidic soil. The three isolates of Heterorhabditis bacteriophora were collected only in open habitats (perennial meadows and uncultivated fields) characterized by strongly acidic soils with sandy loam texture. The virulence of all EPN natural strains was evaluated by laboratory assays against P. japonica third-instar larvae collected during two different periods of the year (spring, autumn). The results showed that larval mortality was higher for pre-wintering larvae than post-wintering ones. The five more promising EPN isolates were tested in the semi-field assay in which H. bacteriophora natural strains have been shown to be more efficient in controlling P. japonica grubs. All of these results are finally discussed considering the use of these natural EPNs as biological control agents against P. japonica, within an eco-friendly perspective of management.

Scent of Jasmine Attracts Alien Invaders and Records on Citizen Science Platforms: Multiple Introductions of the Invasive Lacebug Corythauma ayyari (Drake, 1933) (Heteroptera: Tingidae) in Italy and the Mediterranean Basin.

The jasmine lacebug Corythauma ayyari is a pest of cultivated and ornamental plants mainly associated to Jasminum spp. This invasive insect is native to Asia, and it has been recently introduced in several countries, mainly within the Mediterranean basin. Here, we updated the known distribution of this species, including five new Italian regions (Liguria, Tuscany, Latium, Apulia, and Calabria); Salamis Island in Greece, and the Occitanie region in France. Citizen-science data have significantly contributed to the knowledge on species distribution, and the online platform for sharing biodiversity information can represent an effective tool for the early detection. Molecular analyses revealed that the specimens collected in Peninsular Italy and Sicily belong to a unique clade, suggesting the possibility of a single introduction, whereas those from Menton (France) and Calabria (Southern Italy) are separated from the others and probably originate from separated introductions.

First report of Bursaphelenchus fungivorus (Nematoda: Aphelenchida) in Italy and an overview of nematodes associated with Crocus sativus L.

Saffron is one of the most precious spices in the world. It is derived from the dried stigmas of the Crocus sativus L. flowers. This plant is triploid sterile and propagated by corms. As a subterranean organ, the corm can come into contact with different nematodes. In this contribution Bursaphelenchus fungivorus was reported for the first time in Italy. It was found associated with C. sativus corms and characterized based on morphological and morphometrical characteristics for this species. The identification was confirmed using molecular analyses. Moreover, a review of nematodes associated with C. sativus worldwide is also provided.Saffron is one of the most precious spices in the world. It is derived from the dried stigmas of the Crocus sativus L. flowers. This plant is triploid sterile and propagated by corms. As a subterranean organ, the corm can come into contact with different nematodes. In this contribution Bursaphelenchus fungivorus was reported for the first time in Italy. It was found associated with C. sativus corms and characterized based on morphological and morphometrical characteristics for this species. The identification was confirmed using molecular analyses. Moreover, a review of nematodes associated with C. sativus worldwide is also provided.

Hepatitis B screening in an argentine ED: Increasing vaccination in a resource-limited setting.

BACKGROUND: There is limited data regarding the use of emergency departments (EDs) for infectious disease screening and vaccination in resource-limited regions. In these settings, EDs are often the only contact that patients have with the healthcare system, turning an ED visit into an opportune time to deliver preventative health services. METHODS: In this pilot study, patients that met inclusion criteria were prospectively tested for hepatitis B surface antigen test (HBsAg). Previously unvaccinated patients who tested negative for HBsAg were offered HBV vaccination. The study setting was a public infectious disease hospital in Cordoba, Argentina. The primary outcomes were new HBV diagnoses, as well as vaccination completion between screening modalities (Point-of-Care-Testing-POCT vs. laboratory testing) and same vs. different day vaccination. RESULTS: We screened 100 patients for HBV (75 POCT & 25 laboratory). The median age of participants was 35 years (IQR 24-52) and 55% were male. No patients tested positive for HBsAg. All patients who completed first dose vaccination were initially screened with the POCT. No patients screened with laboratory testing returned for vaccination. Patients who were scheduled for vaccination the same day were more likely to complete vaccination compared to those scheduled for another day (75% vs. 14%, p < .001). CONCLUSION: Our study supports the use of HBV POCTs in the ED in conjunction with vaccination of HBV-negative individuals. In regions with low HBV endemicity, direct vaccination without HBsAg testing may be more cost effective. We believe that this acute-care screening model is applicable to other resource-limited settings.

Assessment of color response and activity rhythms of the invasive black planthopper Ricania speculum (Walker, 1851) using sticky traps.

To be effective, management strategies of invasive alien species cannot ignore their spatiotemporal behavior particularly those exerting serious damages to human activities. The black planthopper Ricania speculum is an Asian insect that has been reported as an alien invasive species in Italy, where it threatens local plant diversity, including important crops. In our work, we analyzed the activity rhythms of this species through circular statistics and the efficiency of chromotropic traps to capture adult individuals. Captures were carried out in central Italy, where the black planthopper is showing a remarkable range expansion, after its first discovery in 2009. We observed that the species was mainly crepuscular, with a high intersexual activity overlap. Activity rhythms changed between July-August and September-October, with changing heliophany, but peaked at sunset and were the lowest in the second half of the night and early morning. The insects were mostly caught by green traps, particularly in September, which is the period of egg-laying inside the leaves; conversely, orange ones were avoided, and yellow ones captured proportionally to their local availability. Strategies for controlling this species should consider concentrating trapping effort during the activity peak, using green sticky traps to enhance the capture success of each trap, with the lowest impact over non-target species.

Developmental stages and gut microenvironments influence gut microbiota dynamics in the invasive beetle Popillia japonica Newman (Coleoptera: Scarabaeidae).

Popillia japonica Newman (Coleoptera: Scarabaeidae) is a highly polyphagous invasive beetle originating from Japan. This insect is highly resilient and able to rapidly adapt to new vegetation. Insect-associated microorganisms can play important roles in insect physiology, helping their hosts to adapt to changing conditions and potentially contributing to an insect's invasive potential. Such symbiotic bacteria can be part of a core microbiota that is stably transmitted throughout the host's life cycle or selectively recruited from the environment at each developmental stage. The aim of this study was to investigate the origin, stability and turnover of the bacterial communities associated with an invasive population of P. japonica from Italy. Our results demonstrate that soil microbes represent an important source of gut bacteria for P. japonica larvae, but as the insect develops, its gut microbiota richness and diversity decreased substantially, paralleled by changes in community composition. Notably, only 16.75% of the soil bacteria present in larvae are maintained until the adult stage. We further identified the micro-environments of different gut sections as an important factor shaping microbiota composition in this species, likely due to differences in pH, oxygen availability and redox potential. In addition, P. japonica also harboured a stable bacterial community across all developmental stages, consisting of taxa well known for the degradation of plant material, namely the families Ruminococcacae, Christensenellaceae and Lachnospiraceae. Interestingly, the family Christensenallaceae had so far been observed exclusively in humans. However, the Christensenellaceae operational taxonomic units found in P. japonica belong to different taxonomic clades within this family.

Evaluation of Scorpion Envenomation by Tityus trivittatus in Adults: An Analysis of Variables Related to Severity of Clinical Presentation.

INTRODUCTION: In Argentina, the scorpion species Tityus trivittatus has been the species most commonly associated with serious injury and death. METHODS: We performed a retrospective study of cases of T trivittatus envenomation that presented to the emergency department at an infectious disease hospital in Cordoba, Argentina, between December 2014 and February 2015. All cases were taxonomically confirmed using criteria established in the Argentine Ministry of Health national guidelines. The primary outcome was classification of clinical presentation (mild/moderate/severe). Classification of clinical presentation was performed in a post hoc fashion using the national guidelines and compared to the classification of clinical presentation given to patients at the time of diagnosis in the emergency department. RESULTS: We included 450 individuals with T trivittatus envenomation. The median age of was 36 y (interquartile range 25-52), and 57% were female. In the emergency department, only 5 patients (<1%) were diagnosed as moderate cases and received antivenom; all other cases were diagnosed as mild. Conversely, in our post hoc classification of clinical presentations, 280 patients had mild presentations, 170 had moderate presentations, and no patients had severe presentations. In our cohort, there were no deaths, no inpatient hospital admissions, and no requirements for continuous cardiac monitoring. We found that age >50 y, (odds ratio [OR] 2.5, P<0.001), time from sting to presentation >120 min (OR 2.6, P=0.02), and pre-existing hypertension (OR=3.9, P<0.001) were all independently associated with worse post hoc classification severity. CONCLUSIONS: Our study exposed factors associated with moderate presentations of scorpion envenomation and proposes the option of conservative treatment for affected adults.

Long-lasting insecticide-treated nets: A new integrated pest management approach for Popillia japonica (Coleoptera: Scarabaeidae).

The Japanese beetle Popillia japonica Newman is a US and EU quarantine insect pest that has recently invaded northern Italy. Its ability to rapidly spread in new areas makes this insect a threat to agriculture. In the last decades, several trials on biological control of the Japanese beetle by entomopathogenic nematodes and fungi have been carried out with variable efficacy. However, the necessity of an integrated pest management approach to improve control has arisen. Long-lasting insecticide-treated nets (LLINs) have been used to control other agricultural pests with an attract-and-kill strategy. Here, we present results from laboratory evaluation of 2 LLINs, Storanet® (BASF™) and ZeroFly® (Vestergaard™), against P. japonica adults. Both were effective in killing the beetles; however, some differences emerged if different exposure times were compared: ZeroFly® always gave 100% mortality in tests from 5-s to 30-min exposure; Storanet® showed 100% mortality only with 30-min exposure and going down to 89%-99% mortality for 5-s to 15-min exposure. A description of the paralysis process occurring at 5-s exposure is given. Possible field application of LLINs within programs of integrated pest management is discussed. Integr Environ Assess Manag 2019;15:259-265. © 2018 SETAC.

Detección de trastornos neurocognitivos en pacientes infectados por HIV mediante pruebas rápidas de cribado / Detection of neurocognitive disorders in patients infected by Human Immunodeficiency Virus through fast screening tests

Introducción: Los trastornos neurocognitivos asociados con el HIV (HAND, por sus siglas en inglés) son altamente prevalentes entre las personas que viven con el virus. Existen tres categorías: demencia asociada a HIV, deterioro neurocognitivo leve y trastorno cognitivo asintomático. Diferentes pruebas de cribado son utilizadas para detectarlos: HIV Dementia Scale (HDS), International Dementia Scale (IHDS) y Mini Mental Test (MMSE). Objetivo: Identificar mediante tres pruebas la presencia de trastornos cognitivos en pacientes infectados con HIV y su relación con diferentes factores de riesgo.Métodos: Estudio prospectivo analítico. Criterios de exclusión: neuroinfecciones, patologías psiquiátricas, uso de drogas de abuso, alcoholismo, TCE y antecedentes de neurocirugía. Resultados: Se incluyeron 51 pacientes entre 18 y 67 años. La prevalencia de HAND fue 25,5%. Presentaban deterioro neurocognitivo: el 66% HDS, 14% IHDS y 29% MMSE; y demencia el 73% HDS, 29% IHDS y 7% MMSE. Se encontró asociación entre HAND y diferentes factores de riego, como edad, desnutrición, nivel instructivo bajo, ≥ tiempo desde el diagnóstico de la infección, bajo recuento de LTCD4+, carga viral detectable y tiempo de inicio de TARV. El 100% de los pacientes tenía al menos un antirretroviral con alta penetración de la barrera hematoencefálica.Conclusiones: Los diferentes grados de deterioro neurocognitivo variaron según la prueba utilizada. Todos los pacientes tratados tenían en su esquema al menos un antirretroviral que atraviesa la barrera hematoencefálica. Factores de riesgo como edad, bajo nivel educativo, bajo peso, carga viral detectable, menor recuento de LTCD4 y tiempo de inicio TARV se asociaron a diferentes grados de deterioro neurocognitivo

Background: HIV-associated neurocognitive disorders (HAND) arehighly prevalent among people living with the virus. There are 3 clinical categories; dementia associated with HIV, mild neurocognitive disorder and asymptomatic neurocognitive disorder. Fast screening tests are used to detect them, such as HIV Dementia Scale (HDS), International HIV Dementia Scale (IHDS) and Mini-mental test (MMSE). The objective of this research was identified through 3 fast screening tests the presence of neurocognitive impairment in patients infected by HIV and his relationship with different risks factors. Methods: Prospective, analytical research.Exclusion criteria: patients with neuroinfections, psychiatric disorders, use of drugs, alcoholism, traumatic brain injury and history of neurosurgery.Results: 51 patients were includedbetween 18 and 67 years old. The prevalence of HAND was 25,5%. 66% HDS, 14% IHDS and 29% MMSE presented neurocognitive impairment; and 73% HDS, 29% IHDS and 7% MMSE exhibited dementia. Significant association was found between HAND and different risk factors like, age, underweight, low educational level, less time since HIV diagnosis, low LTCD4+ count, detectable viral load and time since TARV was initiated. Besides 100% of patients had almost one antiretroviral drug with high penetration through the blood brain barrier.Conclusions: Different levels of neurocognitive disorders varied according to the screening test used. Although all patients treated, had a least one antiretroviral drug which cross the blood brain barrier in their scheme, risk factors such asage, low educational level, underweight, detectable viral load and low LTCD4 level and less time since diagnosis of the infection were associated with different level of neurocognitive disorders.

Hexamermis popilliae n. sp. (Nematoda: Mermithidae) parasitizing the Japanese beetle Popillia japonica Newman (Coleoptera: Scarabaeidae) in Italy.

A new species of mermithid nematode, Hexamermis popilliae n. sp. (Nematoda: Mermithidae) is described from the Japanese beetle Popillia japonica Newman in Italy, an area of new introduction for this invasive pest. The combination of the following characters separates H. popilliae from other members of the genus Hexamermis Steiner, 1924: adult head obtuse; amphidial pouches slightly posterior to lateral head papillae in female but adjacent to lateral head papillae in males; amphidial openings large, well developed; amphidial pouches elliptical in females and oblong in males; cuticular vulvar cone well developed, vulvar lips greatly reduced or lacking, vagina curved at tip where meeting uteri, without reverse bend (not S-shaped), spicules slightly curved, with a slight bend in the basal portion, approximately equal to body width at cloaca. This is the first record of a species of Hexamermis parasitizing the Japanese beetle Popillia japonica. The only previous mention of mermithid nematodes from P. japonica was an undescribed species of Psammomermis in North America. Hexamermis popilliae will be evaluated as a potential biological control agent in an integrated control program of the Japanese beetle in Italy.

Increased Hepatitis E Virus Seroprevalence Correlates with Lower CD4+ Cell Counts in HIV-Infected Persons in Argentina.

Hepatitis E virus (HEV) is a single-stranded RNA virus that can cause hepatitis in an epidemic fashion. HEV usually causes asymptomatic or limited acute infections in immunocompetent individuals, whereas in immunosuppressed individuals such as transplant recipients, HEV can cause chronic infections. The risks and outcomes of HEV co-infection in patients infected with human immunodeficiency virus (HIV) are poorly characterized. We used a third generation immunoassay to measure serum IgG antibodies specific for HEV in 204 HIV-infected individuals from Argentina and a control group of 433 HIV-negative individuals. We found 15 of 204 (7.3%, 95%CI 3.74-10.96%) individuals in the HIV-positive group to have positive HEV IgG levels suggestive of previous infection, compared to 19 of 433 (4.4%, 95% CI 2.5-6.3%) individuals in the HIV-negative control group (p = 0.12). Among HIV-positive individuals, those with HEV seropositivity had lower CD4 counts compared to those that were HEV seronegative (average CD4 count of 234 vs 422 mm3, p = 0.01), indicating that patients with lower CD4 counts were more likely to be HEV IgG positive. Moreover, HEV seropositivity in patients with CD4 counts <200 mm3 was 16%, compared to 4.5% in those with CD4 counts >200 mm3 (p = 0.012). We found a positive PCR result for HEV in one individual. Our study found that increased seroprevalence of HEV IgG correlated with lower CD4 counts in HIV-infected patients in Argentina.