Ophthalmomyiasis Externa and Importance of Risk Factors, Clinical Manifestations, and Diagnosis: Review of the Medical Literature.

OBJECTIVE: This review aims to describe and compare the risk factors, clinical course, diagnosis, and parasitologic features of external ophthalmomyiasis. We also discuss the different preventive measures and the effect of global warming in a large case series reported from January 2000 to December 2022. METHODS: We perform a literature review of reported cases of external ophthalmomyiasis to determine the clinical characteristics, therapeutic management, and information on the organisms that most commonly cause external ophthalmomyiasis. RESULTS: A total of 312 cases of external ophthalmomyiasis were recorded. The most common causative organism was Oestrus ovis (Linnaeus) (Diptera: Oestridae), accounting for 72.1% of cases, followed by Dermatobia hominis (Linnaeus Jr. in Pallas, 1781) (Diptera: Oestridae) at 5.4%, Lucilia sericata (Meigen) (Diptera: Calliphoridae) at 0.96%, and Chrysomyia bezziana (Villeneuve) (Diptera: Calliphoridae) at 0.96%. Before experiencing symptoms, 43.6% of cases reported having direct contact with flies or being hit in the eye, 33% reported no associated risk factors, 9.3% reported living with sheep and goats, and 7.7% reported a history of foreign objects entering the eye. The most common symptoms for those affected by O. ovis were sudden onset, including a foreign body sensation and movement, redness, tearing, itching, swelling, irritation, photophobia, burning, and ocular secretion. In cases caused by D. hominis, symptoms included eyelid edema, pain, redness, itching, movement within the lesion, ocular irritation, and discharge. Regarding occupational or recreational activity, agriculture, and livestock had the highest incidence, followed by trades and technical activities, being a student, and having traveled to an endemic region for work or recreation. CONCLUSION: Patients with red eyes may suffer from external ophthalmomyiasis, which requires a thorough examination to diagnose and treat it early. Moreover, as the temperature increases due to climate change, it is essential to consider how this will affect the spread of different pathogens.

Entomological Survey and Leishmania (Leishmania) mexicana Prevalence in Sand Fly Species during an Outbreak of Cutaneous Leishmaniasis in Quintana Roo State, Mexico.

(1) Background: Localized cutaneous leishmaniasis is a neglected vector-borne disease that has become a serious public health problem in the Yucatan Peninsula. Although more than 60% of cases originate from the state of Quintana Roo, it is one of the least explored areas in terms of incriminating vectors of the Leishmania parasite. Additionally, cases of leishmaniasis have increased substantially in that region in recent years. For this reason, we explored and provided primary evidence of Leishmania DNA in sand fly species from four localities during outbreaks of leishmaniasis in Quintana Roo. We also contributed information on the regional genetic diversity of Leishmania parasites. (2) Methods: Sand flies were collected during several periods from November 2022 to April 2023 using Mosquito Light Circle and Shannon traps, as well as an active entomological search in refuges. For Leishmania detection, we amplified a fragment of 300-350 bp of the internal transcribed spacer subunit 1 (ITS-1). (3) Results: Of the 242 females collected, we detected Leishmania DNA in 25 specimens represented by Bichromomyia olmeca (1), Psathyromyia shannoni (17), Lutzomyia cruciata (4), Psathyromyia undulata (2), and Dampfomyia deleoni (1). The detection of Leishmania in these last two species represents new records for the Yucatan Peninsula and for Mexico. Leishmania (Leishmania) mexicana was the only species detected in the Phlebotominae species, with prevalence values that ranked between 7.41% and 33.33% from specimens collected in the sylvatic areas of Cozumel Island and Petcacab. (4) Conclusions: This study provides the first evidence of infection of Da. deleoni and Pa. undulata by L. (L.) Mexicana. In addition, the presence of three dominant haplotypes in all the evaluated localities was evidenced using the analysis of genetic diversity, and the locality of Petcacab was the one with the circulation of two new haplotypes not previously described in Mexico or neighboring countries. These results highlight the importance of intensive epidemiological surveillance due to the dynamics of transmission of Leishmania between different species.

A new genus and species of gall midge (Diptera: Cecidomyiidae: Cecidomyiidi) with notes on adult cecidomyiid mouthparts and their terminology.

Camillemyia prominens Gagné, gen. n. et sp. n., (Diptera: Cecidomyiidae; Cecidomyiinae) is described for a gall midge from Mexico with an extremely elongate neck and proboscis. The external and internal basic composition of the proboscis of Cecidomyiidae, as exemplified by Cecidomyia resinicola Osten Sacken, is reviewed to help understand the structural changes found in Cam. prominens as compared to those of Contarinia prolixa Gagné & Byers, another species with spectacularly modified mouthparts.

Phylogenetic relations among Mexican phlebotomine sand flies (Diptera: Psychodidae) and their divergence time estimation.

Phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae) have biological relevance as vectors of several pathogens. To ensure periodic entomological monitoring it is necessary to have efficient and accurate tools for an adequate taxonomic identification. There are only few studies on phylogenetic analyses of phlebotomine sand flies from Neotropics, based mostly on morphological and/or molecular data, which makes the delimitation of intra- and interspecific variability of species challenging. Here we generated new molecular information on sand fly species distributed in endemic areas of leishmaniasis in Mexico, using mitochondrial and ribosomal genes, and incorporating morphological information available. Specifically, we established their phylogenetic relationships, and estimated their divergence time. Our study provides molecular information for 15 phlebotomine sand fly species from different areas of Mexico, contributing to the genetic inventory and phylogenetic relations among Neotropical species of the subfamily Phlebotominae. Mitochondrial genes proved to be suitable markers for the molecular identification of phlebotomine sand flies. However, the incorporation of additional nuclear gene information could increase the significance of phylogenetic inferences. We also provided evidence about a possible divergence time of phlebotomine sand fly species, supporting their presumable origin in the Cretaceous period.

Shedding light on the controversial taxonomic status of Culicoides jamaicensis and Culicoides paolae (Diptera: Ceratopogonidae): an overseas trip among continents.

Culicoides biting midges (Diptera: Ceratopogonidae) are small bloodsucking flies that act as vectors for various pathogens of medical and veterinary importance. This study aimed to examine, using a comprehensive approach, the controversial taxonomic status of 2 Culicoides species that are currently distributed in the Neotropical (Culicoides jamaicensis Edwards) and Palearctic (Culicoides paolae Boorman) areas and possess unique and distinctive features. Previous investigations based on morphological analysis have suggested that these 2 species may be synonyms. Our work updated the current geographical distribution of both species and analyzed new specimens from different geographic origins, together with publicly available sequences. We used 2 universal genetic markers (COI and 28S) to test this hypothesis. Our study reveals evidence that C. paolae and C. jamaicensis belong to the same species due to the following statements: (i) similar morphological features; (ii) low interspecific genetic variation; (iii) association with a single genetic cluster; (iv) inclusion within the subgenus Drymodesmyia, which has only been recorded in the New World; and (v) occurrence in habitats with moderate temperatures. We recommend that European and African specimens of C. paolae be considered from now on as C. jamaicensis. Our comprehensive approach shed new light on the taxonomic status of these 2 Culicoides species and has implications for future studies on their biology and ecology.

Triatoma yelapensis sp. nov. (Hemiptera: Reduviidae) from Mexico, with a Key of Triatoma Species Recorded in Mexico.

Thirty-four species of Triatominae (Hemiptera, Reduviidae) are recorded in Mexico, Triatoma Laporte, 1832 the most speciose genus in this country. Here, we describe Triatoma yelapensis sp. nov. from the Pacific coast of Jalisco (Mexico). The most similar species to T. yelapensis sp. nov. is T. recurva (Stål, 1868), but they differ in head longitude, the proportion of labial segments, coloration pattern of corium and connexivum, spiracles location, and male genitalia. To provide statistical support for the morphological distinctiveness of the new species, we performed a geometric morphometric analysis of T. yelapensis sp. nov., T. dimidiata s.s. (Latreille, 1811), T. gerstaeckeri (Stål, 1859), and T. recurva (Stål, 1868), considering head morphology. We also provide an updated key of the genus Triatoma for species recorded in Mexico.

Primer registro de un caso de loxoscelismo cutáneo ocasionado por mordedura de araña violinista (Loxosceles yucatana) en Yucatán, México / First record of a case of cutaneous loxoscelism caused by violin spider (Loxosceles yucatana) bite in Yucatan, Mexico

El loxoscelismo es ocasionado cuando el veneno dermonecrótico producido por las arañas del género Loxosceles, conocidas como «arañas violinistas», ingresa al organismo de una persona a través de su mordida. En México ocurre un subregistro de los casos de loxoscelismo por la ausencia de pruebas de laboratorio para su diagnóstico y la dificultad del cuadro clínico. El objetivo de este trabajo es describir un caso de loxoscelismo cutáneo ocasionado por mordedura de Loxosceles yucatana en un residente de Yucatán, México. El loxoscelismo cutáneo es el tipo más frecuente y menos severo. El presente caso se diagnosticó por medio de la sintomatología registrada en la historia clínica, la lesión inicial y la identificación de arañas L. yucatana. Este trabajo representa la primera descripción de un caso de loxoscelismo cutáneo con resolución favorable en Yucatán.

Loxoscelism occurs when the dermonecrotic venom produced by spiders of the genus Loxosceles, known as "violin spiders," enters a person's organism through their bite. In Mexico there is an underreporting of loxoscelism cases due to the absence of laboratory tests for its diagnosis and the complexity of the clinical picture. The aim of this paper is to describe a case of cutaneous loxoscelism caused by the bite of Loxosceles yucatana in a resident of Yucatan, Mexico. Cutaneous loxoscelism is the most frequent and less severe type. This case was diagnosed by means of the symptomatology registered in the medical records, the initial lesion, and the identification of L. yucatana spiders. This study represents the first description of a case of cutaneous loxoscelism with favorable outcome in Yucatan.

Detection of Wolbachia and Leishmania DNA in sand flies (Diptera: Psychodidae, Phlebotominae) from a focus of cutaneous leishmaniasis in Tabasco, Mexico.

Phlebotomine sand flies are the main vectors of Leishmania genus species worldwide; therefore, the detection of some reproductive parasites, such as Wolbachia, has been considered a possible strategy for biological control. In Mexico, leishmaniasis cases have been recorded in 25 states, yet only two sand fly species have been related to Wolbachia spp. Although the state of Tabasco has a high number of leishmaniasis cases, only few studies have been done on sand fly species. The aim of this study was to analyze the diversity of sand fly species and to detect Wolbachia spp. and/or Leishmania spp. in the captured specimens. Sand flies were collected at the locality of Huimango, Tabasco, Mexico, during October 2019, using nine light traps (CDC) and two Shannon traps per night. The specimens were identified and females were analyzed by PCR for the DNA detection for pathogens. A total of 193 sand fly specimens belonging to five species were morphologically identified. Pintomyia ovallesi was the most abundant species (76.84%), followed by Micropygomyia cayennensis (6.40%). Furthermore, first records of four sand fly species were established for the state of Tabasco, thereby increasing the species richness in the state from four to eight. We observed a natural infection rate of 9.7% (10/103) for Leishmania and 0.91% (1/103) for Wolbachia. The importance of conducting entomological surveys in endemic areas of leishmaniasis in Mexico is highlighted, to determine whether other sand fly species may be potential vectors of Leishmania spp., and if some Wolbachia strains could be relevant for the control of leishmaniasis.

First record of a case of cutaneous loxoscelism caused by violin spider (Loxosceles yucatana) bite in Yucatan, Mexico. / Primer registro de un caso de loxoscelismo cutáneo ocasionado por mordedura de araña violinista (Loxosceles yucatana) en Yucatán, México.

Loxoscelism occurs when the dermonecrotic venom produced by spiders of the genus Loxosceles, known as "violin spiders," enters a person's organism through their bite. In Mexico there is an underreporting of loxoscelism cases due to the absence of laboratory tests for its diagnosis and the complexity of the clinical picture. The aim of this paper is to describe a case of cutaneous loxoscelism caused by the bite of Loxosceles yucatana in a resident of Yucatan, Mexico. Cutaneous loxoscelism is the most frequent and less severe type. This case was diagnosed by means of the symptomatology registered in the medical records, the initial lesion, and the identification of L. yucatana spiders. This study represents the first description of a case of cutaneous loxoscelism with favorable outcome in Yucatan.

El loxoscelismo es ocasionado cuando el veneno dermonecrótico producido por las arañas del género Loxosceles, conocidas como «arañas violinistas¼, ingresa al organismo de una persona a través de su mordida. En México ocurre un subregistro de los casos de loxoscelismo por la ausencia de pruebas de laboratorio para su diagnóstico y la dificultad del cuadro clínico. El objetivo de este trabajo es describir un caso de loxoscelismo cutáneo ocasionado por mordedura de Loxosceles yucatana en un residente de Yucatán, México. El loxoscelismo cutáneo es el tipo más frecuente y menos severo. El presente caso se diagnosticó por medio de la sintomatología registrada en la historia clínica, la lesión inicial y la identificación de arañas L. yucatana. Este trabajo representa la primera descripción de un caso de loxoscelismo cutáneo con resolución favorable en Yucatán.

A new species of Dixella, the first Mexican record of Dixella shannoni, and a summary of dixid records from Mexico (Diptera: Dixidae).

We describe a new species of the genus Dixella Dyar Shannon of Mexico. Specimens were collected in Lagunas de Santo Domingo, Municipality of Huatusco, Veracruz, a small vegetation-lined lake within an increasingly relictual mountain cloud forest. This species is most closely related to Dixella cumbrica Peters Cook, 1966, based upon the shape of the apical lobe of the gonocoxite and flattened gonostylus. Also, we include the first record of Dixella shannoni (Lane, 1942), in Mexico, based upon specimens collected in Santiago Yaveo, Oaxaca. Additionally, we present a list of all localities in which dixids have been collected in Mexico.

Rhipicephalus sanguineus Complex in the Americas: Systematic, Genetic Diversity, and Geographic Insights.

The Rhipicephalus sanguineus group encompasses at least 12 validated species of Palearctic and Afrotropical hard ticks, which are relevant in veterinary medicine and public health. The taxonomy of R. sanguineus s.s., has been particularly intensely debated, due to its wide geographic distribution, morphological variants, parasite-host associations, and its capacity and vectorial competence for the transmission of several pathogens. By sequencing mitochondrial markers, it was possible to identify the existence of multiple lineages, among which the Tropical and the Temperate lineages stand out, particularly in America. However, the northern limit between these lineages is not clear due to the lack of extensive sampling across Mexico. For this reason, the aim of the present study was to determine the genetic diversity and structure of the R. sanguineus group in Mexico and to compare it with the populations reported in the Americas, in order to propose the northern limit of the R. sanguineus Tropical lineage and the potential regions of sympatry with R. sanguineus s.s. The findings of this study now confirm the presence of R. sanguineus s.s. in Mexico, showing a subtle genetic structure and high genetic diversity throughout its distribution in the Americas. In contrast, the Tropical lineage seems to be genetically less diverse in its overall distribution in the Americas. The genetic diversity of these two independent lineages could have important epidemiological implications in the transmission of tick pathogens.

A new species of predaceous midge in the genus Stilobezzia Kieffer from Mexico (Diptera: Ceratopogonidae).

The predaceous midges (Diptera: Ceratopogonidae; tribe Ceratopogonini) in the genera Schizonyxhelea Clastrier Stilobezzia Kieffer in Mexico were recently addressed by Huerta Grogan (2017) who described one new species in each of these genera. A re-examination of specimens in the Colección de Artrópodos con Importancia Medica (CAIM), from the states of Morelos and Yucatan, revealed an undescribed species that was previously identified as Stilobezzia (Stilobezzia) femoralis Lane Forattini from Yucatan by Huerta (2002) and Huerta Grogan (2017). Herein, we describe and illustrate this species from the states of Morelos Yucatan, Mexico, as Stilobezzia (Stilobezzia) tobiasi Huerta Grogan n. sp.

Back from the past: Molecular and morphological support for Simulium mutucuna Nunes de Mello & Vieira da Silva, 1974 (Diptera: Simuliidae) as a valid species.

Simulium mutucuna, a species described based on a single female from Roraima state, was previously synonymized with Simulium paynei and currently is considered a synonym of Simulium rubrithorax. In the present paper we present morphological and molecular evidence supporting the validity of S. mutucuna based on analysis of specimens from Brazil, Venezuela and Mexico. We redescribe the female and describe, for the first time, the male, pupa and larva of S. mutucuna and discuss the morphological differences between this species and the others that are already considered as its senior synonyms. Currently, the distribution of S. mutucuna is restricted to Roraima state. The distribution record for S. rubrithorax in Brazil's North region needs to be removed, since the previous records were based on occurrence of S. mutucuna. Finally, we present new evidence of cryptic diversity in the S. paynei complex based on molecular information.

Asian Tiger Mosquito in Yucatan Peninsula: First Record of Aedes (Stegomyia) albopictus (Diptera: Culicidae) in Campeche, Mexico.

This report describes the presence of Aedes albopictus Skuse (Diptera: Culicidae) in Yucatan Peninsula and represents the first record of the Asian tiger invasive mosquito in Campeche State, southeastern Mexico. We collected specimens using 11,326 ovitraps put into houses of urban and rural areas, as part of the entomological surveillance by the local Ministry of Health from January 2019 to February 2020. We found Ae. albopictus in five of the 12 municipalities of Campeche (San Francisco de Campeche, Tenabo, Hecelchakán, Calkíni and Escárcega). We record 68 positive ovitraps and 226 Ae. albopictus larvae. This finding increases the number of mosquito species recorded in Campeche, Mexico, and possibly the potential for 22 arbovirus transmission.

A new species of Setostylus Matile and new records of Setostylus bellulus (Williston) (Diptera: Keroplatidae).

Setostylus xoxo spec. nov., is described and illustrated from Morelos, Mexico and southern Arizona, USA and is compared with similar Neotropical congeners. Additionally, the first records of Setostylus bellulus (Williston) are provided from Guatemala and Costa Rica and an updated key to the New World species of Setostylus is presented.

Nosocomial Myiasis Caused by Lucilia sericata (Diptera: Calliphoridae) in a Pediatric Patient in Mexico.

Prevention of nosocomial myiasis, or hospital-acquired larvae infestation, should be an essential part of all hospital infection control programs. However, little is known about nosocomial myiasis, despite the extensive medical and psychological effects it has on patients and their families and the negative effects it has on hospitals' reputation and finances. This report describes a case of nosocomial myiasis of a 13-year-old boy who was admitted to a pediatric intensive care unit for congestive heart failure, anemia, uremic encephalopathy, hypertension, and severe respiratory distress. Ten days after admission, the pediatrician and the nurse perceived an increase in the volume of the gingival mucosa of the upper buccal vestibule and the presence of fly larvae. The maggots were sent to the Instituto de Diagnostico y Referencia Epidemiologicos for identification and were found to be Lucilia sericata larvae. This report highlights the need to educate medical and paramedical personnel, as well as creation and implement protocols in hospitals to avoid nosocomial myiasis and improvement of general sanitation.

Olbiogaster Osten Sacken (Diptera: Anisopodidae) from Mexico, with the description of three new species.

Three new species of the genus Olbiogaster Osten Sacken-Olbiogaster halffteri sp. nov., Olbiogaster nuxco sp. nov. and Olbiogaster puuc sp. nov.-are described and illustrated from Mexico, based on adult males and females collected in the states of Guerrero, Puebla and Yucatan. Comments for the species known from Mexico and key are provided.

Psectrosciara Kieffer in Mexico (Diptera: Scatopsidae): two new species and additional records for the genus.

Two new species of Psectrosciara Kieffer from Mexico-Psectrosciara ahuatla sp. nov. and Psectrosciara otumba sp. nov., both belonging to the scatopsiformis-group, are described and illustrated based on males and females collected in Neotropical (Acapulco and Nuxco in the State of Guerrero) and Nearctic (Coyotepec, in the State of Mexico) areas in Mexico. We have a new record of Psectrosciara serrata Cook from Jalisco (in the Biological Station of Chamela) and females from different parts of Mexico. A key for the species of Psectrosciara from Mexico is presented.

A new species and the first record of the genus Micrapemon Edwards (Diptera: Keroplatidae) from Mexico.

The first record of the genus Micrapemon Edwards from Mexico is presented, with the description and illustration of a new species, Micrapemon maya spec. nov., based on adult males collected with Malaise traps from Yucatan (natural reserves of Ria Celestun and Ria Lagartos). The new species from Mexico is compared with the two previously known species from the Neotropical region, Micrapemon majusculum (Edwards) and Micrapemon parvum (Williston). A key is included to the species of the genus.