Plasmodium vivax is the most prevalent cause of human malaria in the world and can lead to severe disease with high potential for relapse. Its genetic and geographic diversities make it challenging to control. P. vivax is understudied and to achieve control of malaria in endemic areas, a rapid, accurate, and simple diagnostic tool is necessary. In this pilot study, we found that a colorimetric system using AuNPs and MSP10 DNA detection in urine can provide fast, easy, and inexpensive identification of P. vivax. The test exhibited promising sensitivity (84%), high specificity (97%), and only mild cross-reactivity with P. falciparum (21%). It is simple to use, with a visible color change that negates the need for a spectrometer, making it suitable for use in austere conditions. Using urine eliminates the need for finger-prick, increasing both the safety profile and patient acceptance of this model. To control malaria, there is an urgent need for applying innovative diagnostics and new technologies. Nanoparticles can augment detection of malaria at lower parasite levels while providing fast and simple methodology. Novel use of MSP10 and gold nanoparticles to identify Plasmodium vivax’s DNA in urine can be utilized as screening tool with global application potentials. The proposed test could impact the control of the most common species of malaria in low resource settings as it could present a simple, fast, cheap and easy to interpret test. Furthermore, utilizing urine instead of blood eliminates the need for finger-prick which would increase safety profile and likely increase participation rate in mass screening programs.

It has been suggested that pets play a critical role in the maintenance of methicillin‐resistant (MR) and multidrug‐resistant (MDR) Staphylococcus spp. in the household. We examined risk factors for carriage of antimicrobial‐resistant coagulase‐positive staphylococci, with particular attention to Staphylococcus aureus and Staphylococcus pseudintermedius isolated from pets living in households of people diagnosed with methicillin‐resistant S. aureus (MRSA) skin or soft‐tissue infection. We analyzed data collected cross‐sectionally from a study conducted in 2012 that evaluated the transmission of MRSA and other staphylococci from humans, their pets and the environment (Pets and Environmental Transmission of Staphylococci [PETS] study). We used unadjusted and adjusted stratified logistic regression analyses with household‐clustered standard errors to evaluate the association between demographic, healthcare‐related, contact‐related and environmental risk factors and MDR Staphylococcus spp. isolated from dogs and cats. Staphylococcal isolates obtained from dogs (n = 63) and cats (n = 47) were included in these analyses. The use of oral or injectable antimicrobials by the pets during the prior year was the main risk factor of interest. Based on our results, 50% (12/24) of S. aureus, 3.3% (1/30) of S. pseudintermedius and 25% (14/56) of other coagulase‐positive staphylococci (CPS) were determined to be MDR. S. aureus isolates were more likely to be MDR compared with S. pseudintermedius. We did not find a significant statistical association between the use of oral or injectable antimicrobials in the prior year and the presence of MDR bacteria. The results suggest that drivers of antimicrobial resistance in household staphylococci may vary by bacterial species, which could have implications for one health intervention strategies for staphylococci and inform the investigation of other reverse zoonoses, such as COVID‐19.

Quantitative polymerase chain reaction (qPCR) for Toxoplasma gondii multicopy genes has emerged as a promising strategy for sensitive detection of parasite DNA. qPCR can be performed from blood samples, which are minimally invasive to collect. However, there is no consensus about what type of blood specimen yields the best sensitivity. The development of a novel protocol for qPCR detection of T. gondii using blood clot, involving an appropriate DNA extraction method and the use of an internal amplification control to monitor the reaction is presented in the current study. Assays directed to the B1 and REP529 genes were performed in spiked specimens of whole blood, guanidine–ethylenediaminetetraacetic acid blood, and clot. The clot-based qPCR was shown to be more sensitive when compared with other types of specimens, detecting five and 0.05 T. gondii genomes, using B1 and REP529 targets, respectively. Finally, a comparative analysis with samples from HIV patients with clinical suspicion of toxoplasmosis was performed, demonstrating the detection of four positive suspected cases with clots compared with only one using guanidine–ethylenediaminetetraacetic acid blood. The high analytical sensitivity and the cost-effective advantages offered by clot supports this methodology as a good laboratory tool to monitor parasite burden.

SARS-CoV-2 can infect a variety of wild and domestic animals worldwide. Of these, domestic cats are highly susceptible species and potential viral reservoirs. As such, it is important to investigate disease exposure in areas with active community transmission and high disease prevalence. In this report we demonstrate the presence of serum neutralizing antibodies against the receptor binding-domain (RBD) of the SARS-CoV-2 in cats whose owners had been infected with SARS-CoV-2 in Lima, Peru, using a commercial competitive ELISA SARS-CoV-2 Surrogate Virus Neutralization Test. Out of 41 samples, 17.1% (7/41) and 31.7% (13/41) were positive, using the cut-off inhibition value of 30% and 20%, respectively. Not all cats living in a single house had detectable neutralizing antibodies showing that heterogenous exposure and immune among cohabiting animals. This is the first report of SARS-COV-2 exposure of domestic cats in Lima, Peru. Further studies are required to ascertain the prevalence of SARS-COV-2 exposure among domestic cats of Lima, Peru.

Rickettsiae are a family of ectoparasite-borne bacteria that can produce high morbidity and mortality among humans. There are scarce data on rickettsial ecology in rural areas of the Peruvian Amazon basin, where seroprevalence has not been determined, and the identities of animals acting as reservoirs of these bacteria are not known. We conducted a cross-sectional study in Zungarococha (between 2019 and 2021), a rural community located approximately 20 km away from Iquitos city. Blood samples were collected from humans (175), dogs (123), and cats (12). Blood samples and tissues were collected from black rats (84). Finally, we collected fleas from dogs and cats (222), ticks from dogs (91), and mites from black rats (32). Blood samples from humans, dogs, cats, and black rats were analyzed by indirect immunofluorescence assays (IFA) to detect IgG antibodies against rickettsias. We screened ectoparasites and black rat tissues by real-time-PCR (qPCR). Positive ectoparasites were further assessed by PCR and DNA amplicon sequencing. Non-parametric tests were used to evaluate factors associated with being seropositive among human adults. IgG seroprevalences were 38.3 %, 58.5 %, 16.7 % and 48.1 % among humans, dogs, cats, and rats, respectively. Among humans, only male gender was statistically associated with having IgG antibodies against Rickettsia spp. (p-value=0.049, chi-square test). Different ectoparasites were identified, including Ctenocephalides felis from cats and dogs, Rhipicephalus sanguineus s.l. from dogs, and Laelaps nuttalli from black rats. Rhipicephalus sanguineus s.l. (2/91 ticks) and Ct. felis (53/56 fleas and 55/55 flea pools) were qPCR-positive for Rickettsia spp. Recovered genetic material from 53 Ct. felis was sequenced and all were identified as Rickettsia asembonensis. All tissue samples from black rats were negative by qPCR. Humans, dogs, cats, and black rats are exposed to spotted fever group rickettsiae in rural areas surrounding Iquitos. As reported in urban areas, R. asembonensis is the main Rickettsia species circulating in rural areas surrounding Iquitos and Ct. felis appears to be the main vector.