Serological evidence for potential yellow fever virus infection in non-human primates, southeastern Mexico.

BACKGROUND: Arthropod-borne flaviviruses like dengue virus (DENV) and yellow fever virus (YFV) are major human pathogens. In Latin America, YFV is maintained in sylvatic cycles involving non-human primates (NHP) and forest-dwelling mosquitos. YFV supposedly does not circulate north of Panama. METHODS: We conducted a serologic study for flaviviruses and other emerging viruses in NHP from southeastern Mexico. A total of thirty sera of black-handed spider monkeys (Ateles geoffroyi, n = 25), black howler monkeys (Alouatta pigra, n = 3), and mantled howler monkeys (Al. palliata, n = 2) sampled in 2012 and 2018 were screened by an indirect immunofluorescence assay (IFA) to detected IgG antibodies against DENV, YFV, Zika virus (ZIKV), West Nile virus (WNV), Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus, Middle East respiratory syndrome coronavirus, and Zaire Ebola virus, and confirmed by plaque reduction neutralization tests (PRNT90) representing all mosquito-borne flavivirus serocomplexes circulating in the Americas. RESULTS: A total of 16 sera (53.3%; 95% CI, 34.3-71.7) showed IFA reactivity to at least one tested flavivirus with end-point titers ranging from 1:100 to 1:1000. No serum reacted with other viruses. Monotypic and high mean PRNT90 endpoint YFV titers of 1:246 were found in 3 black-handed spider monkey sera (10.0%; 95% CI, 2.1-26.5) sampled in 2018 in Tabasco, compared to all other flaviviruses tested. Monotypic endpoint PRNT90 titers of 1:28 for Ilheus virus and 1:22 for WNV in serum of black howler monkeys sampled in 2018 in Tabasco suggested additional flavivirus exposure. CONCLUSIONS: Our findings may suggest unnoticed YFV circulation. Intensification of YFV surveillance in NHP and vectors is warranted in Mexico and potentially other areas considered free of yellow fever.

Experimental infection of Artibeus lituratus bats and no detection of Zika virus in neotropical bats from French Guiana, Peru, and Costa Rica suggests a limited role of bats in Zika transmission.

Bats are important natural reservoir hosts of a diverse range of viruses that can be transmitted to humans and have been suggested to play an important role in the Zika virus (ZIKV) transmission cycle. However, the exact role of these animals as reservoirs for flaviviruses is still controversial. To further expand our understanding of the role of bats in the ZIKV transmission cycle in Latin America, we carried out an experimental infection in wild-caught Artibeus lituratus bats and sampled several free-living neotropical bats across three countries of the region. Experimental ZIKV infection was performed in wild-caught adult bats (4 females and 5 males). The most relevant findings were hemorrhages in the bladder, stomach and patagium. Significant histological findings included inflammatory infiltrate consisting of a predominance of neutrophils and lymphocytes, in addition to degeneration in the reproductive tract of males and females. This suggests that bat reproduction might be at some level affected by ZIKV. Leukopenia was also observed in some inoculated animals. Hemorrhages, genital alterations, and leukopenia are suggested to be caused by ZIKV; however, since these were wild-caught bats, we cannot exclude other agents. Detection of ZIKV by qPCR was observed at low concentrations in only two urine samples in two inoculated animals. All other animals and tissues tested were negative. Finally, no virus-neutralizing antibodies were found in any animal. To determine ZIKV infection in nature, the blood of a total of 2056 bats was sampled for ZIKV detection by qPCR. Most of the sampled individuals belonged to the genus Pteronotus sp. (23%), followed by the species Carollia sp. (17%), Anoura sp. (14%), and Molossus sp. (13.7%). No sample of any tested species was positive for ZIKV by qPCR. These results together suggest that bats are not efficient amplifiers or reservoirs of ZIKV and may not have an important role in ZIKV transmission dynamics.

Rabies virus in white-nosed coatis (Nasua narica) in Mexico: what do we know so far?

Rabies is a neglected disease that affects all mammals. To determine the appropriate sanitary measures, the schedule of preventive medicine campaigns requires the proper identification of the variants of the virus circulating in the outbreaks, the species involved, and the interspecific and intraspecific virus movements. Urban rabies has been eradicated in developed countries and is being eradicated in some developing countries. In Europe and North America, oral vaccination programs for wildlife have been successful, whereas in Latin America, Asia, and Africa, rabies remains a public health problem due to the habitation of a wide variety of wild animal species that can act as rabies virus reservoirs in their environment. After obtaining recognition from the WHO/PAHO as the first country to eliminate human rabies transmitted by dogs, Mexico faces a new challenge: the control of rabies transmitted by wildlife to humans and domestic animals. In recent years, rabies outbreaks in the white-nosed coati (Nasua narica) have been detected, and it is suspected that the species plays a significant role in maintaining the wild cycle of rabies in the southeast of Mexico. In this study, we discussed cases of rabies in white-nosed coatis that were diagnosed at InDRE (in English: Institute of Epidemiological Diagnosis and Reference; in Spanish: Instituto de Diagnostico y Referencia Epidemiologicos) from 1993 to 2022. This study aimed to determine whether white-nosed coatis might be an emergent rabies reservoir in the country. A total of 13 samples were registered in the database from the Rabies laboratories of Estado de Mexico (n = 1), Jalisco (n = 1), Quintana Roo (n = 5), Sonora (n = 1), and Yucatan (n = 5). Samples from 1993 to 2002 from Estado de Mexico, Jalisco, and Sonora were not characterized because we no longer had any samples available. Nine samples were antigenically and genetically characterized. To date, coatis have not been considered important vectors of the rabies virus. The results from our research indicate that the surveillance of the rabies virus in coatis should be relevant to prevent human cases transmitted by this species.

Rabies Virus Variants Detected from Cougar (Puma concolor) in Mexico 2000-2021.

In 2019, the World Health Organization (WHO) and the Pan-American Health Organization (PAHO) recognized Mexico as a country free of human rabies transmitted by dogs. Nevertheless, the sylvatic cycle remains as a public health concern in the country. Although cougars (Puma concolor) are not reservoirs of any rabies virus variant (RVV), these felines could act as vectors at the top of the food chain, and their relationships with other organisms must be considered important for the regulatory effect on their prey's populations. In this study, genetic and antigenic characterization was performed on all cougar rabies cases diagnosed at the Rabies Laboratory Network of the Ministry of Health (RLNMH) in Mexico from 2000 to 2021. Samples from other species, a skunk, a horse (Equus caballus) (attacked by a cougar), and a gray fox (Urocyon cineroargenteus), were included as reference. Rabies cases in cougars were restricted to two Northern states of Mexico (Sonora and Chihuahua). Five out of six samples of cougars were RVV7 (Arizona gray fox RVV) and one from Sonora was RVV1. Interestingly, there is no evidence of RVV1 in dogs in the Northern states since the 1990s but skunk species now harbor this RVV1 in this region of the country.

Natural co-infection of divergent hepatitis B and C virus homologues in carnivores.

In humans, co-infection of hepatitis B and C viruses (HBV, HCV) is common and aggravates disease outcome. Infection-mediated disease aggravation is poorly understood, partly due to lack of suitable animal models. Carnivores are understudied for hepatitis virus homologues. We investigated Mexican carnivores (ringtails, Bassariscus astutus) for HBV and HCV homologues. Three out of eight animals were infected with a divergent HBV termed ringtail HBV (RtHBV) at high viral loads of 5 × 109 -1.4 × 1010 copies/ml serum. Two of the RtHBV-infected animals were co-infected with a divergent hepacivirus termed ringtail hepacivirus (RtHV) at 4 × 106 -7.5 × 107 copies/ml in strain-specific qRT-PCR assays. Immunofluorescence assays relying on HBV core and RtHV NS3/4a proteins indicated that none of the animals had detectable hepadnavirus core-specific antibodies, whereas one RtHV-infected animal had concomitant RtHV-specific antibodies at 1:800 end-point titre. RtHBV and RtHV complete genomes showed typical HBV and HCV structure and length. All RtHBV genomes were identical, whereas RtHV genomes showed four amino acid substitutions located predominantly in the E1/E2-encoding genomic regions. Both RtHBV (>28% genomic nucleotide sequence distance) and RtHV (>30% partial NS3/NS5B amino acid sequence distance) formed new species within their virus families. Evolutionary analyses showed that RtHBV grouped with HBV homologues from different laurasiatherian hosts (carnivores, bats, and ungulates), whereas RtHV grouped predominantly with rodent-borne viruses. Ancestral state reconstructions showed that RtHV, but not RtHBV, likely emerged via a non-recent host switch involving rodent-borne hepacivirus ancestors. Conserved hepatitis virus infection patterns in naturally infected ringtails indicate that carnivores may be promising animal models to understand HBV/HCV co-infection.

Public Veterinary Medicine: Public Health Rabies virus variants identified in Nuevo Leon State, Mexico, from 2008 to 2015.

OBJECTIVE: To identify rabies virus variants (RVVs) isolated from bats and terrestrial mammals in Nuevo Leon between 2008 and 2015 and Coahuila in 2006. SAMPLE: RVVs isolated from 15 bats and terrestrial mammals in Nuevo Leon and from a cow (Bos taurus) in Coahuila, along with 46 reference rabies virus sequences. PROCEDURES: Antigenic characterization of the 16 isolates was performed with an indirect fluorescent antibody technique. Genomic sequencing of the nucleoprotein gene in the 16 isolates was performed with a reverse transcription PCR assay. Phylogenetic reconstruction of the 62 sequences was performed by means of Bayesian inference. RESULTS: 9 isolates from bats and 1 isolate from a domestic cat that became infected as a result of contact with a Mexican free-tailed bat all clustered in the lineage associated with Lasiurus spp in the Americas or the lineage associated with Tadarida brasiliensis mexicana. An isolate from a domestic dog was identified as a variant associated with the dog-coyote lineage. The RVV isolated from a fox clustered in an Arizona fox lineage. The 3 RVVs from skunks (Mephitis macroura) were placed in a lineage with variants isolated from spotted skunks (Spilogale putorius). The RVV isolated from the cow was clustered in a lineage associated with foxes in Texas and separate from the lineage for the fox from Nuevo Leon. CONCLUSIONS AND CLINICAL RELEVANCE: Results reinforced the need for Mexico to implement rabies surveillance and monitoring programs for bats and wild-living terrestrial carnivores.

Transmisión vertical del virus de la rabia cría-madre, fenómeno que podría mantener al virus en especies reservorios de vida silvestre.

INTRODUCTION: The biological test established by the World Health Organization to isolate and amplify the rabies virus consists in inoculating lactating mice by intracranial route and detecting rabies signs for 21 days. OBJECTIVE: To verify viral transmission in mothers of rabies virus-inoculated lactating mice. METHOD: Twenty-seven Mexican rabies virus isolates were inoculated by intracranial route in lactating mice, which were observed for 21 days. The mothers were observed for 60 days. The diagnosis was established by immunofluorescence in brain tissue. The virus was characterized by sequencing and with monoclonal antibodies. RESULTS: All litters showed rabies at between 7 and 15 days post-inoculation (p. i.). Three of the 27 females (11 %) had developed rabies at days 33, 37 and 39 p. i. of their litters. Viral characterization showed that the mothers were infected with the same variant of their offspring, two of them stemming from hematophagous bat and one from dog. The liters that transmitted rabies to their mothers were nine individuals. CONCLUSIONS: In nature, the rabies virus could be preserved by transmission from neonates (more susceptible to contracting and amplifying the rabies virus) to their mothers.

INTRODUCCIÓN: La prueba biológica establecida por la Organización Mundial de la Salud para aislar y amplificar el virus de la rabia consiste en inocular vía intracraneal ratones lactantes para detectar signos de rabia en un periodo de 21 días. OBJETIVO: Constatar el contagio viral en las madres de ratones lactantes inoculados con virus de la rabia. MÉTODO: Veintisiete aislados mexicanos de virus de la rabia se inocularon vía intracraneal en ratones lactantes, los cuales fueron observados por 21 días y sus madres, por 60 días. El diagnóstico se llevó a cabo mediante inmunofluorescencia en cerebro. El virus se caracterizó por secuenciación y anticuerpos monoclonales. RESULTADOS: Todas las camadas presentaron rabia entre siete y 15 días posinoculación (p. i.); tres de las 27 hembras (11 %), a los días 33, 37 y 39 p. i. de sus crías. La caracterización viral mostró que las madres se infectaron con la misma variante de sus crías, dos procedían de murciélago hematófago y una de perro. Las camadas que trasmitieron rabia a sus madres fueron nueve individuos. CONCLUSIONES: En la naturaleza, el virus de la rabia podría preservarse mediante la transmisión de los neonatos (más susceptibles de contraer y amplificar el virus) a sus madres.

Transmisión vertical del virus de la rabia cría-madre, fenómeno que podría mantener al virus en especies reservorios de vida silvestre / Vertical transmission of the rabies virus from calf to mother, a phenomenon that could maintain the virus in reservoir species of wildlife

Resumen Introducción: La prueba biológica establecida por la Organización Mundial de la Salud para aislar y amplificar el virus de la rabia consiste en inocular vía intracraneal ratones lactantes para detectar signos de rabia en un periodo de 21 días. Objetivo: Constatar el contagio viral en las madres de ratones lactantes inoculados con virus de la rabia. Método: Veintisiete aislados mexicanos de virus de la rabia se inocularon vía intracraneal en ratones lactantes, los cuales fueron observados por 21 días y sus madres, por 60 días. El diagnóstico se llevó a cabo mediante inmunofluorescencia en cerebro. El virus se caracterizó por secuenciación y anticuerpos monoclonales. Resultados: Todas las camadas presentaron rabia entre siete y 15 días posinoculación (p. i.); tres de las 27 hembras (11 %), a los días 33, 37 y 39 p. i. de sus crías. La caracterización viral mostró que las madres se infectaron con la misma variante de sus crías, dos procedían de murciélago hematófago y una de perro. Las camadas que trasmitieron rabia a sus madres fueron nueve individuos. Conclusiones: En la naturaleza, el virus de la rabia podría preservarse mediante la transmisión de los neonatos (más susceptibles de contraer y amplificar el virus) a sus madres.

Abstract Introduction: The biological test established by the World Health Organization to isolate and amplify the rabies virus consists in inoculating lactating mice by intracranial route and detecting rabies signs for 21 days. Objective: To verify viral transmission in mothers of rabies virus-inoculated lactating mice. Method: Twenty-seven Mexican rabies virus isolates were inoculated by intracranial route in lactating mice, which were observed for 21 days. The mothers were observed for 60 days. The diagnosis was established by immunofluorescence in brain tissue. The virus was characterized by sequencing and with monoclonal antibodies. Results: All litters showed rabies at between 7 and 15 days post-inoculation (p. i.). Three of the 27 females (11 %) had developed rabies at days 33, 37 and 39 p. i. of their litters. Viral characterization showed that the mothers were infected with the same variant of their offspring, two of them stemming from hematophagous bat and one from dog. The liters that transmitted rabies to their mothers were nine individuals. Conclusions: In nature, the rabies virus could be preserved by transmission from neonates (more susceptible to contracting and amplifying the rabies virus) to their mothers.

Redescription of Periglischrus herrerai (Acari: Spinturnicidae) Associated to Desmodus rotundus (Chiroptera: Phyllostomidae: Desmodontinae), With a Description of Adult Female Heteromorphism and an Analysis of its Variability Throughout the Neotropics.

A redescription, with a discussion of new features and illustrations, for all life stages is presented for the parasitic mite Periglischrus herrerai Machado-Allison associated with the common vampire bat Desmodus rotundus (Geoffoy), including a description of the heteromorphic female and the first description of its female deutonymph. In addition, the morphological variation of P. herrerai is evaluated by morphometric analysis of the adults, concluding that there is an evident geographic variation throughout the neotropics. This study was possible by using type material of P. herrerai from the Machado-Allison collection, and voucher specimens from other collections, and specimens from an extensive surveying of hematophagous bats in some localities of the Pacific and Atlantic versants, and central Mexico.