David Moran

The New World screwworm, Cochliomyia hominivorax (Diptera: Calliphoridae), is an obligate parasitic fly that causes severe myiasis in livestock, wildlife, and humans, generating substantial economic and public health impacts. Following its historical eradication from North and Central America through sterile insect technique (SIT) programs, recent outbreaks in Central America and southern Mexico indicate ongoing biological reinvasion. We evaluated current and future environmental suitability for C. hominivorax using ecological niche modeling (Maximum Entropy [MaxEnt]) calibrated with 1,972 occurrence records derived from 10,204 outbreak reports across Mexico and Central America. Models were developed using WorldClim bioclimatic variables under current climatic conditions (1970–2000) and future climate scenarios (Shared Socioeconomic Pathways [SSPs]: SSP1-2.6 and SSP5-8.5 for 2050). Suitable environments currently encompass most of Central America and 27 of 32 Mexican states, with highest suitability concentrated in southeastern Mexico. Future projections indicated expansion and intensification of highly suitable areas, particularly in the Yucatán Peninsula, Chiapas, and Tabasco. Spatial analysis of 238 human myiasis cases reported in Mexico during 2025–2026 revealed significant aggregation within highly suitable areas predicted by the models (χ2 = 179.3, P < 0.001). These findings suggest that environmental suitability is spatially associated with the current reemergence of C. hominivorax and may facilitate further expansion under climate change. Our results highlight the need for strengthened surveillance, regional biosecurity strategies, and coordinated One Health interventions to prevent large-scale reinfestation across Mesoamerica.

Rhipicephalus microplus is a globally significant one-host tick that primarily infests cattle. In the Neotropics, this species has been reported on various wild mammals—such as cervids, tapirs, rodents, bats, carnivores and primates—as well as occasionally from humans. Here we report a rare case of R. microplus infestation in a rescued black howler (Alouatta pigra) from Melchor de Mencos, Petén, Guatemala. This tick-host association, documented at the ARCAS Wildlife Rescue Centre, highlights the expanding host range of R. microplus and emphasises the importance of continued surveillance regarding its health consequences in wildlife, zoonotic potential, and host adaptability.

Wild aquatic birds are considered the natural hosts of 16 HA (H1–H16) and 9 NA (N1–N9) subtypes of influenza A viruses (FLUAV) found in different combinations. H14 FLUAVs are rarely detected in nature. Since 2011, H14 FLUAVs have been consistently detected in Guatemala, leading to the largest collection of this subtype from a single country. All H14 FLUAVs in Guatemala were detected from blue-winged teal samples. In this report, 17 new full-length H14 FLUAV genome sequences detected from 2014 until 2019 were analyzed and compared to all published H14 sequences, including Guatemala, North America, and Eurasia. The H14 FLUAVs identified in Guatemala were mostly associated with the N3 subtype (n = 25), whereas the rest were paired with either N4 (n = 7), N5 (n = 4), N6 (n = 1), and two mixed infections (N3/N5 n = 2, and N2/N3 n = 1). H14 FLUAVs in Guatemala belong to a distinct H14 lineage in the Americas that is evolving independently from the Eurasian H14 lineage. Of note, the ORF of the H14 HA segments showed three distinct motifs at the cleavage site, two of these containing arginine instead of lysine in the first and fourth positions, not previously described in other countries. The effects of these mutations on virus replication, virulence, and/or transmission remain unknown and warrant further studies.

Guatemala has held dog rabies mass vaccination campaigns countrywide since 1984, yet the virus remains endemic. To eliminate dog-mediated human rabies, dog vaccination coverage must reach at least 70%. The Guatemala rabies program uses a 5:1 human:dog ratio (HDR) to estimate the vaccination coverage; however, this method may not accurately reflect the heterogeneity of dog ownership practices in Guatemalan communities. We conducted 16 field-based dog population estimates in urban, semi-urban and rural areas of Guatemala to determine HDR and evaluate the standard 5:1. Our study-derived HDR estimates varied from 1.7–11.4:1 (average 4.0:1), being higher in densely populated sites and lowest in rural communities. The community-to-community heterogeneity observed in dog populations could explain the persistence of rabies in certain communities. To date, this is the most extensive dog-population evaluation conducted in Guatemala, and can be used to inform future rabies vaccination campaigns needed to meet the global 2030 rabies elimination targets.

As countries with endemic canine rabies progress towards elimination by 2030, it will become necessary to employ techniques to help plan, monitor, and confirm canine rabies elimination. Sequencing can provide critical information to inform control and vaccination strategies by identifying genetically distinct virus variants that may have different host reservoir species or geographic distributions. However, many rabies testing laboratories lack the resources or expertise for sequencing, especially in remote or rural areas where human rabies deaths are highest. We developed a low-cost, high throughput rabies virus sequencing method using the Oxford Nanopore MinION portable sequencer. A total of 259 sequences were generated from diverse rabies virus isolates in public health laboratories lacking rabies virus sequencing capacity in Guatemala, India, Kenya, and Vietnam. Phylogenetic analysis provided valuable insight into rabies virus diversity and distribution in these countries and identified a new rabies virus lineage in Kenya, the first published canine rabies virus sequence from Guatemala, evidence of rabies spread across an international border in Vietnam, and importation of a rabid dog into a state working to become rabies-free in India. Taken together, our evaluation highlights the MinION’s potential for low-cost, high volume sequencing of pathogens in locations with limited resources.

Rabies is a fatal encephalitis caused by rabies virus, of the genus Lyssavirus. The principal reservoir for rabies in Latin America is the common vampire bat (Desmodus rotundus), which feeds routinely on the blood of cattle, and when livestock are scarce, may prey on other mammals, including humans. Although rabies is endemic in common vampire bat populations in Guatemala, there is limited research on the extent of exposure to bats among human populations living near bat refuges. A random sample of 270 of 473 households (57%) in two communities located within 2 Km of a known bat roost was selected and one adult from each household was interviewed. Exposure to bats (bites, scratches or bare skin contact) was reported by 96 (6%) of the 1,721 residents among the selected households. Of those exposed, 40% received rabies post-exposure prophylaxis. Four percent of household respondents reported that they would seek rabies post exposure prophylaxis if they were bitten by a bat. These findings demonstrate that exposure to bats in communities near bat roosts is common but recognition of the potential for rabies transmission from bats is low. There is a need for educational outreach to raise awareness of bat-associated rabies, prevent exposures to bats and ensure appropriate health-seeking behaviours for bat-inflicted wounds, particularly among communities living near bat roosts in Guatemala.