Toxoplasmosis is a cosmopolitan zoonosis that particularly threatens pregnant women, their fetuses and immunocompromised individuals. Among people living with HIV, Toxoplasma gondii may invade the central nervous system, producing neuropathological effects associated with mental and psychiatric disorders. We assessed the seroprevalence of anti-T. gondii IgG in HIV-infected and HIV-uninfected residents of Iquitos, Peru, and evaluated an in-house ELISA based on total lysate antigen (TLA) and recombinant GRA1 (rGRA1), with ELISA-TLA compared against a commercial kit. In this observational cross-sectional study, 151 participants were enrolled: 92 HIV-positive and 59 HIV-negative. ELISA-TLA showed a seroprevalence of 88.08% (133/151), reaching 91.30% (84/92) in the HIV-positive group and 83.05% (49/59) in the HIV-negative group. ELISA-rGRA1 showed a similar epidemiological pattern but lower overall seroprevalence, 81.46% (123/151), with 84.78% (78/92) in HIV-positive and 74.58% (44/59) in HIV-negative participants. Taken together, both TLA and rGRA1-based ELISAs showed similar epidemiological patterns, supporting the consistency of the serological findings. These results also indicate very high exposure to T. gondii in Iquitos, particularly among HIV-positive individuals, in whom prior exposure is clinically relevant because of the risk of reactivation under immunosuppression. Serological screening and preventive counseling may therefore be warranted in high-burden Amazonian communities.

IntroductionThis study investigates the occurrence of Leptospira spp., Toxoplasma gondii, and respiratory viruses in invasive black rats (Rattus rattus) from Punta San Juan (PSJ), a coastal protected area in southern Peru. Rodents can harbor zoonotic pathogens at the wildlife–human interface, posing ecological and public health risks.MethodsFifty-three rats were trapped inside and outside PSJ in June 2025 from two contrasting zones: inside PSJ (n = 29), corresponding to the protected coastal habitat within the reserve, and outside PSJ (n = 24), including adjacent urban and human-impacted coastal areas. Serum, blood, and tissues were analyzed for T. gondii using Western blot and quantitative PCR. Leptospira spp. detection was performed by real-time PCR targeting the lipL32 gene in blood samples. Respiratory viruses, including influenza A and B, were screened using the Illumina Respiratory Virus Panel through next-generation sequencing (NGS) technology in respiratory tract and lung swabs.ResultsOne adult female (1/49, 2.0%) captured inside PSJ was seropositive for T. gondii, but all PCR tests were negative in blood and tissues. Leptospira spp. DNA was detected in 18/53 rats (34.0%), with higher frequency outside the reserve (54.2%) than inside (17.2%) (p = 0.008). No amplifications were obtained for respiratory viruses.DiscussionThe higher Leptospira frequency outside PSJ suggests that human-associated environments increase infection risk in the study area. In contrast, evidence for other zoonotic pathogens was limited, with only a single serological detection of T. gondii and no respiratory viruses identified. Although these findings are restricted to a local context, they highlight Leptospira spp. as the primary zoonotic pathogen detected and support the need for broader surveillance to better assess the epidemiological role of invasive rodents in coastal protected areas.

The environmental spread of antibiotic-resistant bacteria is a growing global health concern, particularly in low- and middle-income countries where limited wastewater treatment infrastructure may facilitate the dissemination of multidrug-resistant (MDR) organisms. Escherichia coli and Klebsiella spp. are clinically significant MDR pathogens commonly associated with healthcare-associated infections and known to carry diverse antimicrobial resistance genes (ARGs). In this study, we conducted genomic and phenotypic analyses of E. coli and Klebsiella spp. isolated from hospital wastewater and paediatric patient samples at a tertiary hospital in Lima, Peru, between 2017 and 2019. A total of 157 isolates were collected (E. coli, n=113; Klebsiella spp., n=44). Whole-genome sequencing was performed to identify ARGs and assess sequence types (STs). MDR phenotypes were more prevalent among wastewater isolates (73.5%) compared to clinical isolates (56.8%, P=0.014), while extended-spectrum β-lactamase production was more frequent in clinical isolates (52.9 % vs. 13.9 %, P<0.001). Carbapenemase-producing isolates were found only in wastewater, whereas colistin resistance was restricted to a subset of clinical E. coli isolates from urine. Genomic analysis revealed greater sequence type diversity among wastewater isolates, including high-risk STs such as ST10, ST131 and ST405. The Shannon diversity index was higher for wastewater-derived isolates (H=3.45) compared to clinical isolates (H=2.95), indicating a more heterogeneous resistance reservoir. In total, 1,302 resistance gene hits were identified, with clinical isolates carrying significantly more ARGs per genome than wastewater isolates. A small number of shared STs were detected in both sources, suggesting possible overlap in bacterial populations. Our findings highlight the potential role of hospital wastewater as a reservoir of antimicrobial resistance and support the value of integrating environmental and clinical genomic surveillance. Wastewater-based monitoring may inform infection control efforts and guide interventions to curb the spread of AMR within healthcare settings and their surrounding environments.

Toxoplasma gondii infection can pose a significant health risk, particularly among immunocompromised individuals, such as people living with HIV (PLHIV). This study aimed to evaluate the seroprevalence of T. gondii and associated factors among PLHIV and individuals who are HIV negative in two distinct regions of Peru: Iquitos and Lima. We conducted a cross-sectional study, enrolling 281 participants (100 PLHIV and 181 HIV- negative participants). An in-house ELISA was used to detect IgG antibodies against T. gondii after ensuring that its performance was comparable with the commercially available Vircell ELISA kit. Our in-house ELISA demonstrated high reliability, with a positive agreement of 98.3% and a negative agreement of 100% with the Vircell ELISA kit. The overall seroprevalence of T. gondii was 62.3%, with significantly higher rates observed in Iquitos (88.0%) than in Lima (29.3%). People living with HIV showed a notably higher prevalence ratio (PR) for T. gondii seropositivity in both cities, with PRs of 1.18 (95% CI, 1.07-1.29) in Iquitos and 2.29 (95% CI, 1.30-4.05) in Lima. This study highlights the significant regional disparities in T. gondii seroprevalence between Iquitos and Lima, which may be driven by environmental and socioeconomic factors. Our findings underscore the need for region-specific public health interventions to mitigate the impact of T. gondii infections in PLHIV in Peru. Enhanced public health strategies, including improved access to clean water and sanitation in high-risk areas like Iquitos, may be important to reduce the burden of T. gondii and prevent severe complications in vulnerable populations.

Toxoplasma gondii is a ubiquitous zoonotic protozoan parasite that infects a wide variety range of warm-blooded animals. This study describes the epidemiological scenario of T. gondii in an indigenous community that relies on subsistence hunting in a well-conserved and isolated area of the Peruvian Amazon. The high seropositivity against T. gondii in humans (83.3% IgG and 6.1% IgM), wild mammals (30.45%, 17 species), peri-domestic rodents (10.0% Rattus sp.), and domestic animals (94.1% dogs and 100% cats) indicates the existence of a sylvatic cycle in the community under study. Individual age was found to be positively associated with IgG detection against T. gondii but not with IgM. It is estimated that each family consumed 5.67 infected animals per year with terrestrial species having higher infective rates than arboreal species. The main risk factors included improper handling and cooking of wild meat, poor hygiene practices, and feeding uncooked offal to domestic animals. This scenario results in a continuous process of infection and reinfection within the indigenous community with cats, dogs, and peri-domestic animals becoming infected through the ingestion of infected raw viscera. Our results emphasize the need to promote safe food handling practices and disposal of waste materials from hunted animals in such communities.

Children living in low-resource settings are frequently gut-colonized with multidrug-resistant bacteria. We explored whether breastfeeding may protect against children's incident gut colonization with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) and Klebsiella, Enterobacter, or Citrobacter spp. (ESBL-KEC). We screened 937 monthly stool samples collected from 112 children aged 1-16 months during a 2016-19 prospective cohort study of enteric infections in peri-urban Lima. We used 52,816 daily surveys to examine how exposures to breastfeeding in the 30 days prior to a stool sample were associated with children's risks of incident gut-colonization, controlling for antibiotic use and other covariates. We sequenced 78 ESBL-Ec from 47 children to explore their diversity. Gut-colonization with ESBL-Ec was increasingly prevalent as children aged, approaching 75% by 16 months, while ESBL-KEC prevalence fluctuated between 18% and 36%. Through 6 months of age, exclusively providing human milk in the 30 days prior to a stool sample did not reduce children's risk of incident gut-colonization with ESBL-Ec or ESBL-KEC. From 6 to 16 months of age, every 3 additional days of breastfeeding in the prior 30 days was associated with 6% lower risk of incident ESBL-Ec gut-colonization (95% CI: 0.90, 0.98, p = .003). No effects were observed on incident ESBL-KEC colonization. We detected highly diverse ESBL-Ec among children and few differences between children who were predominantly breastfed (mean age: 4.1 months) versus older children (10.8 months). Continued breastfeeding after 6 months conferred protection against children's incident gut colonization with ESBL-Ec in this setting. Policies supporting continued breastfeeding should be considered in efforts to combat antibiotic resistance.

OBJECTIVES.:To evaluate the variation of hematological profiles of patients infected with uncomplicated Plasmodium vivax (Pv) and P. falciparum (Pf) malaria before, during and after treatment in a population of the Loreto region. MATERIALS AND METHODS.:This study was conducted between 2010 and 2012, in Zungarococha (Iquitos). The 425 participants had three visits (visit 1-day 0-before treatment, visit 2-day 7-during treatment, visit 3-day 28-after treatment), complete blood count, microscopic and molecular diagnosis (PCR). RESULTS.:At the first visit, 93 (21.9%) participants were found positive for Pv and 34 (8.0%) for Pf. All positives showed a reduction in hematocrit, white blood cell count (WBC), ablated and segmented neutrophils, eosinophils and platelets (p<0.001) compared to the negative group. A higher percentage of ablated neutrophils was found in Pf and segmented neutrophils in Pv compared to the negative group. Variations in hematological profiles were observed after treatment for both species; ablated neutrophils decreased, platelets increased, eosinophils increased at day 7 and declined at day 28, hematocrit and segmented neutrophils decreased at day 7 and normalized at day 28. Interspecies differences over time showed a bigger daily decrease in ablated neutrophils in Pv-infected when compared to Pf. CONCLUSIONS.:The hematological profile in uncomplicated malaria-positive patients varies over time during and after treatment. These are indicators of disease progression and help in the therapeutic surveillance of Plasmodium-infected patients.

Congenital transmission of Trypanosoma cruzi is an important source of new Chagas infections worldwide. The mechanisms of congenital transmission remain poorly understood, but there is evidence that parasite factors are involved. Investigating changes in parasite strain diversity during transmission could provide insight into the parasite factors that influence the process. Here we use amplicon sequencing of a single copy T. cruzi gene to evaluate the diversity of infection in clinical samples from Chagas positive mothers and their infected infants. Several infants and mothers were infected with multiple parasite strains, mostly of the same TcV lineage, and parasite strain diversity was higher in infants than mothers. Two parasite haplotypes were detected exclusively in infant samples, while one haplotype was never found in infants. Together, these data suggest multiple parasites initiate a congenital infection and that parasite factors influence the probability of vertical transmission.

Background:Neurological opportunistic infections cause significant morbidity and mortality in people with human immunodeficiency virus (HIV) but are difficult to diagnose. Methods:One hundred forty people with HIV with acute neurological symptoms from Iquitos, Peru, were evaluated for cerebral toxoplasmosis with quantitative polymerase chain reaction (qPCR) of cerebrospinal fluid (CSF) and for cryptococcal meningitis with cryptococcal antigen test (CrAg) in serum or CSF. Differences between groups were assessed with standard statistical methods. A subset of samples was evaluated by metagenomic next-generation sequencing (mNGS) of CSF to compare standard diagnostics and identify additional diagnoses. Results:Twenty-seven participants were diagnosed with cerebral toxoplasmosis by qPCR and 13 with cryptococcal meningitis by CrAg. Compared to participants without cerebral toxoplasmosis, abnormal Glasgow Coma Scale score (P = .05), unilateral focal motor signs (P = .01), positive Babinski reflex (P = .01), and multiple lesions on head computed tomography (CT) (P = .002) were associated with cerebral toxoplasmosis. Photophobia (P = .03) and absence of lesions on head CT (P = .02) were associated with cryptococcal meningitis. mNGS of 42 samples identified 8 cases of cerebral toxoplasmosis, 7 cases of cryptococcal meningitis, 5 possible cases of tuberculous meningitis, and incidental detections of hepatitis B virus (n = 1) and pegivirus (n = 1). mNGS had a positive percentage agreement of 71% and a negative percentage agreement of 91% with qPCR for T gondii. mNGS had a sensitivity of 78% and specificity of 100% for Cryptococcus diagnosis. Conclusions:An infection was diagnosed by any method in only 34% of participants, demonstrating the challenges of diagnosing neurological opportunistic infections in this population and highlighting the need for broader, more sensitive diagnostic tests for central nervous system infections.

Tuberculosis remains one of the leading causes of death worldwide, especially in low- and middle-income countries. Tuberculosis treatment and control efforts are hindered by the difficulty in making the diagnosis, as currently available diagnostic tests are too slow, too expensive, or not sufficiently sensitive. Recombinase polymerase amplification (RPA) is a novel technique that allows for the amplification of DNA rapidly, at constant temperature, and with minimal expense. We calculated and compared the limit of detection, sensitivity, and specificity of two RPA-based assays for the diagnosis of pulmonary tuberculosis, using two sets of published primers. We also calculated and compared the assays’ limits of detection and compared their performance using two different DNA extraction methods prior to amplification (a commercially available DNA extraction kit vs. the chelex method). The RPA-lateral flow assay had a limit of detection of 5 fg/μL of DNA, a sensitivity of 53.2%, and a specificity of 93.3%, while the real time-RPA assay had a limit of detection of 25 fg/μL of DNA, a sensitivity of 85.1%, and a specificity of 93.3%. There was no difference in assay performance when DNA extraction was carried out using the commercial kit vs. the chelex method. The real-time RPA assay has adequate sensitivity and specificity for the diagnosis of pulmonary tuberculosis and could be a viable diagnostic tool in resource-limited settings, but the lateral flow assay did not perform as well, perhaps due to the fact we used stored sputum specimens from a biorepository. More work is needed to optimize the RPA-lateral flow assay, to get a more accurate estimate of its specificity and sensitivity using prospectively collected specimens, and to develop both assays into point-of-care tests that can be easily deployed in the field.

Poultry farming represents Peru's primary food animal production industry, where antimicrobial growth promoters are still commonly used, exerting selective pressure on intestinal microbial populations. Consumption and direct animal-to-human transmission have been reported, and farmworkers are at high risk of colonization with resistant bacteria. We conducted a cross-sectional survey among 54 farmworkers to understand their current antimicrobial resistance (AMR) awareness in Ica, Peru. To gain insight into the potential work-related risk of exposure to bacteria, we also measured the AMR rates in Escherichia coli isolated among 50 broiler chickens. Farmworkers were unaware of antimicrobial resistance (31.5%) or antibiotic resistance (16.7%) terms. Almost two-thirds (61%) consumed antibiotics during the previous month, and only 42.6% received a prescription from a healthcare professional. A total of 107 E. coli chicken isolates were obtained, showing a high frequency of multidrug-resistant (89.7%) and extended-spectrum beta-lactamase (ESBL) production (71.9%). Among ESBL-producer isolates, 84.4% carried the blaCTX-M gene. Results identified gaps in knowledge that reflect the need for interventions to increase antimicrobial awareness among poultry farmworkers. The high AMR rates among E. coli isolates highlight the need to reduce antimicrobial use in poultry farms. Our findings reveal a critical need for effective policy development and antimicrobial stewardship interventions in poultry production in Ica, Peru.

Objetivos. Evaluar la variación de los perfiles hematológicos antes, durante y después del tratamiento de pacientes infectados con malaria no complicada por Plasmodium vivax (Pv) y P. falciparum (Pf) en una población de la región Loreto. Materiales y métodos. El estudio se realizó entre 2010 y 2012, en Zungarococha (Iquitos). Los 425 participantes tuvieron tres visitas (visita 1-día 0-antes del tratamiento, visita 2-día 7-durante tratamiento, visita 3-día 28-después del tratamiento), hemograma completo, diagnóstico microscópico y molecular (PCR). Resultados. En la primera visita, se encontraron 93 (21,9%) positivos a Pv y 34 (8,0%) a Pf. Todos los positivos mostraron una reducción en los indicadores hematológicos de hematocrito, recuento de glóbulos blancos (RGB), neutrófilos abastonados y segmentados, eosinófilos y plaquetas (p<0.001) en comparación con el grupo negativo. Se encontró un porcentaje mayor de neutrófilos abastonados en Pf y de neutrófilos segmentados en Pv comparado al grupo negativo. Se observó variaciones en los perfiles hematológicos después del tratamiento para ambas especies, los neutrófilos abastonados disminuyeron, las plaquetas aumentaron, los eosinófilos se incrementaron al día 7 y decaen el día 28, el hematocrito y los neutrófilos segmentados disminuyeron al día 7 y se normalizaron el día 28. Las diferencias entre especies en el tiempo mostraron una disminución diaria de neutrófilos abastonados en infectados con Pv que en Pf. Conclusiones. El perfil hematológico en pacientes positivos a malaria no complicada varía en el tiempo durante y después del tratamiento. Estos son indicadores de la progresión de la enfermedad y ayudan en la vigilancia terapéutica de pacientes infectados con Plasmodium.

Chagas disease, caused by Trypanosoma cruzi, can reactivate and cause severe acute disease in immunocompromised patients such as those infected with human immunodeficiency virus (HIV). We conducted amplicon deep sequencing of a 327-bp fragment of the tcscd5 gene using an Ion Torrent PGM directly from clinical samples from HIV patients with high parasitemia. We describe the within-host diversity, both characterizing the discrete typing unit of the infections and confirming the presence of multistrain infections, directly from clinical samples. This method can rapidly provide information on the genetic diversity of T. cruzi infection, which can have direct impacts on clinical disease.