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Background: Fleas and ticks serve as vectors of multiple pathogens in the genera Rickettsia and Bartonellathat cause diseases in humans and other animals. Although human rickettsiosis and bartonellosis have been reported in all countries in Central America, limited research has been conducted to investigate the natural cycles of flea- and tick-borne rickettsiosis and bartonellosis, especially in Guatemala. Methods: We evaluated dog parasites as sentinels for zoonotic disease risk in rural Guatemala by sampling ticks and fleas from dogs, which were then identified and individually screened for Rickettsia and Bartonella. Results: A total of 77 households were surveyed and 80.52% of them had dogs. Overall, 133 dogs were examined for fleas and ticks, of which 68.42% had fleas and 35.34% had ticks. A total of 433 fleas and 181 ticks were collected from the infested dogs, with an additional 33 ticks collected from house walls. Three flea species were identified: Ctenocephalides felis (70%), Echidnophaga gallinacea(11.8%), and Pulex sp. (17.8%). Among the collected ticks, 97% were Rhipicephalus sanguineus with the rest being Amyblyomma cajennense, A. auricularium, and A. ovale. Rickettsia felis were detected in six C. felis, in one Pulex sp., and in two R. sanguineus, while Candidatus R. senegalensis was detected in one C. felis. Bartonella was detected only in fleas, including three Pulexsp. infected with B. vinsonii subsp. Berkhoffii, B. henselae, and Bartonella sp., respectively, and 11 C. felis infected with B. henselae. Conclusions: This study reports Candidatus R. senegalensis and B. vinsonii subsp. Berkhoffiiin Guatemala for the first time, and indicates the potential risk of human and dog exposure to Rickettsia and Bartonella species. These results show that dogs provide critical information relevant to managing human potential exposure to flea- and tick-borne pathogens in rural Guatemala.
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The global circulation of SARS-CoV-2 has been extensively documented, yet the dynamics within Central America, particularly Nicaragua, remain underexplored. This study characterizes the genomic diversity of SARS-CoV-2 in Nicaragua from March 2020 through December 2022, utilizing 1064 genomes obtained via next-generation sequencing. These sequences were selected nationwide and analyzed for variant classification, lineage predominance, and phylogenetic diversity. We employed both Illumina and Oxford Nanopore Technologies for all sequencing procedures. Results indicated a temporal and spatial shift in dominant lineages, initially from B.1 and A.2 in early 2020 to various Omicron subvariants towards the study's end. Significant lineage shifts correlated with changes in COVID-19 positivity rates, underscoring the epidemiological impact of variant dissemination. The comparative analysis with regional data underscored the low diversity of circulating lineages in Nicaragua and their delayed introduction compared to other countries in the Central American region. The study also linked specific viral mutations with hospitalization rates, emphasizing the clinical relevance of genomic surveillance. This research advances the understanding of SARS-CoV-2 evolution in Nicaragua and provide valuable information regarding its genetic diversity for public health officials in Central America. We highlight the critical role of ongoing genomic surveillance in identifying emergent lineages and informing public health strategies.
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Major dengue epidemics throughout Nicaragua's history have been dominated by 1 of 4 dengue virus serotypes (DENV-1-4). To examine serotypes during the dengue epidemic in Nicaragua in 2022, we performed real-time genomic surveillance in-country and documented cocirculation of all 4 serotypes. We observed a shift toward co-dominance of DENV-1 and DENV-4 over previously dominant DENV-2. By analyzing 135 new full-length DENV sequences, we found that introductions underlay the resurgence: DENV-1 clustered with viruses from Ecuador in 2014 rather than those previously seen in Nicaragua; DENV-3, which last circulated locally in 2014, grouped instead with Southeast Asia strains expanding into Florida and Cuba in 2022; and new DENV-4 strains clustered within a South America lineage spreading to Florida in 2022. In contrast, DENV-2 persisted from the formerly dominant Nicaragua clade. We posit that the resurgence emerged from travel after the COVID-19 pandemic and that the resultant intensifying hyperendemicity could affect future dengue immunity and severity.
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COVID-19 , Vírus da Dengue , Dengue , Filogenia , SARS-CoV-2 , Sorogrupo , Vírus da Dengue/genética , Vírus da Dengue/classificação , Nicarágua/epidemiologia , Humanos , Dengue/epidemiologia , Dengue/virologia , COVID-19/epidemiologia , COVID-19/virologia , SARS-CoV-2/genética , PandemiasRESUMO
Aedes mosquitoes, as vectors of medically important arthropod-borne viruses (arboviruses), constitute a major public health threat that requires entomological and epidemiological surveillance to guide vector control programs to prevent and reduce disease transmission. In this study, we present the collaborative effort of one year of mosquito-based arbovirus surveillance in two geographically distinct regions of Latin America (Nicaragua and Ecuador). Adult female mosquitoes were collected using backpack aspirators in over 2,800 randomly selected households (Nicaragua, Ecuador) and 100 key sites (Nicaragua) from eight distinct communities (Nicaragua: 2, Ecuador: 6). A total of 1,358 mosquito female pools were processed for RNA extraction and viral RNA detection using real-time RT-PCR. Ten positive dengue virus (DENV) pools were detected (3 in Nicaragua and 7 in Ecuador), all of which were found during the rainy season and matched the serotypes found in humans (Nicaragua: DENV-1 and DENV-4; Ecuador: DENV-2). Infection rates ranged from 1.13 to 23.13, with the Nicaraguan communities having the lowest infection rates. Our results demonstrate the feasibility of detecting DENV-infected Aedes mosquitoes in low-resource settings and underscore the need for targeted mosquito arbovirus sampling and testing, providing valuable insights for future surveillance programs in the Latin American region.
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BACKGROUND: Dengue virus, a major global health threat, consists of four serotypes (DENV1-4) that cause a range of clinical manifestations from mild to severe and potentially fatal disease. METHODS: This study, based on 19 years of data from the Pediatric Dengue Cohort Study and Pediatric Dengue Hospital-based Study in Managua, Nicaragua, investigates the relationship of serotype and immune status with dengue severity. Dengue cases were confirmed by molecular, serological, and/or virological methods, and sudy participants 6 months to 17 years old were followed during their hospital stay or as ambulatory patients. RESULTS: We enrolled a total of 15,266 participants, of whom 3,227 (21%) were positive for DENV infection. Of 2,630 cases with serotype result by RT-PCR, 557 corresponded to DENV1, 992 to DENV2, 759 to DENV3 and 322 to DENV4. Severe disease was more prevalent among secondary DENV2 and DENV4 cases, while similar disease severity was observed in both primary and secondary DENV1 and DENV3 cases. According to the 1997 World Health Organization (WHO) severity classification, both DENV2 and DENV3 caused a higher proportion of severe disease compared to other serotypes, whereas DENV3 caused the greatest percentage of severity according to the WHO-2009 classification. DENV2 was associated with increased odds of pleural effusion and low platelet count, while DENV3 was associated with both hypotensive and compensated shock. CONCLUSIONS: These findings demonstrate differences in dengue severity by serotype and immune status and emphasize the critical need for a dengue vaccine with balanced effectiveness against all four serotypes, particularly as existing vaccines show variable efficacy by serotype and serostatus.
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Community engagement strategies provide tools for sustainable vector-borne disease control. A previous cluster randomized control trial engaged nine intervention communities in seven participatory activities to promote management of the domestic and peri-domestic environment to reduce risk factors for vector-borne Chagas disease. This study aims to assess the adoption of this innovative community-based strategy, which included chickens' management, indoor cleaning practices, and domestic rodent infestation control, using concepts from the Diffusion of Innovations Theory. We used questionnaires and semi-structured interviews to understand perceptions of knowledge gained, intervention adoption level, innovation attributes, and limiting or facilitating factors for adoption. The analysis process focused on five innovation attributes proposed by the Diffusion of Innovations Theory: relative advantage, compatibility, complexity, trialability, and observability. Rodent management was highly adopted by participants, as it had a relative advantage regarding the use of poison and was compatible with local practices. The higher complexity was reduced by offering several types of trapping systems and having practical workshops allowed trialability. Observability was limited because the traps were indoors, but information and traps were shared with neighbors. Chicken management was not as widely adopted due to the higher complexity of the method, and lower compatibility with local practices. Using the concepts proposed by the Diffusion of Innovations Theory helped us to identify the enablers and constraints in the implementation of the Chagas vector control strategy. Based on this experience, community engagement and intersectoral collaboration improve the acceptance and adoption of novel and integrated strategies to improve the prevention and control of neglected diseases.
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Galinhas , Colaboração Intersetorial , Animais , Humanos , Conhecimento , Doenças Negligenciadas , Fatores de RiscoRESUMO
Mosquitoes and the diseases they transmit continue to place millions of people at risk of infection around the world. Novel methods of vector control are being developed to provide public health officials with the necessary tools to prevent disease transmission and reduce local mosquito populations. However, these methods will require public acceptance for a sustainable approach and evaluations at local settings. We present our efforts in community engagement carried out in colonias of the Lower Rio Grande Valley in south Texas for mosquito surveillance, control, and ecological projects. Along the US-Mexico border the term colonia refers to impoverished communities that are usually inhabited by families of Hispanic heritage. The different engagements were carried out from September 2016 to February 2019; during this time, we had three distinct phases for community engagement. In Phase 1 we show the initial approach to the colonias in which we assessed security and willingness to participate; in Phase 2 we carried out the first recruitment procedure involving community meetings and house-to-house recruitment; and in Phase 3 we conducted a modified recruitment procedure based on community members' input. Our findings show that incorporating community members in the development of communication materials and following their suggestions for engagement allowed us to generate culturally sensitive recruitment materials and to better understand the social relationships and power dynamics within these communities. We were able to effectively reach a larger portion of the community and decrease the dropout rate of participants. Progress gained with building trust in the communities allowed us to convey participant risks and benefits of collaborating with our research projects. Community engagement should be viewed as a key component of any local vector control program as well as for any scientific research project related to vector control. Even in the face of budgetary constraints, small efforts in community engagement go a long way.
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Hispânico ou Latino , Controle de Mosquitos , Animais , Humanos , México , Texas/epidemiologiaRESUMO
Las heridas crónicas de origen traumático, con exposición de tejidos, requieren de un desbridamiento adecuado, lavado y una pronta cubierta para evitar la infección y la desecación. A veces, incluso deben ser ampliadas para realizar un adecuado desbridamiento quirúrgico; por lo que, al intentar una cobertura completa, el resultado es una herida a tensión, que se complica con inflamación, infección y la dehiscencia que se acentúa aún más si está en una zona de flexión, como la rodilla. Se presenta el caso de una paciente de 28 años, que acudió a emergencias con un antecedente de herida traumática en la rodilla derecha, signos de retraso de la cicatrización, tejido de granulación friable, exposición de la rótula, abundante secreción serosa y dolor al movimiento con rango limitado. Se la trató en un solo tiempo quirúrgico con desbridamiento, irrigación y cobertura completa de la herida mediante la técnica de "pie-crusting". Nivel de Evidencia: IV
Chronic wounds of traumatic origin, with tissue exposure, require adequate debridement, lavage and prompt coverage to prevent infection and desiccation. Wounds may even require to be enlarged in order to perform an adequate surgical debridement. Enlarged wound attempts to perform a complete coverage may result in tension wound closures, which are complicated by inflammation, infection, and dehiscence and aggravated when located on flexure areas, such as on the knee. We report the case of a 28-year female patient, who presented to the Emergency Department with a history of traumatic wound in the right knee and signs of delayed healing, friable granulation tissue, exposed patella, increased serous drainage, and painful limited range of motion. She underwent a single surgical time procedure with debridement, irrigation, and complete coverage of the wound with the help of the pie-crusting technique. Level of Evidence: IV
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Adulto , Desbridamento , Técnicas de Fechamento de Ferimentos , Ferida Cirúrgica , Articulação do JoelhoRESUMO
INTRODUCTION: Chagas disease, a neglected tropical disease that affects millions of Latin Americans, has been effectively controlled in Guatemala after multiple rounds of indoor residual insecticide spraying (IRS). However, a few foci remain with persistent Triatoma dimidiata infestation. One such area is the municipality of Comapa, Department of Jutiapa, in the southeastern region of Guatemala, where control interventions appear less effective. We carried out three cross sectional entomological and serological surveys in Comapa to evaluate a decade of vector control activities. Baseline serological (1999) and entomological (2001-2) surveys were followed by three rounds of insecticide applications (2003-2005) and intermittent focal spraying of infested houses, until approximately 2012. Household inspections to determine entomological indices and construction materials were conducted in 2001, 2007 and 2011. Seroprevalence surveys were conducted in school-age children in 1999, 2007 and 2015, and in women of child bearing age (15-44 years) only in 2015. After multiple rounds of indoor residual sprayings (IRS), the infestation index decreased significantly from 39% (2001-2) to 27% (2011). Household construction materials alone predicted <10% of infested houses. Chagas seroprevalence in Comapa declined in school-aged children by 10-fold, from 10% (1999) to 1% (2015). However, seroprevalence in women of child bearing age remains >10%. CONCLUSION: After a decade of vector control activities in Comapa, there is evidence of significantly reduced transmission. However, the continued risk for vector-borne and congenital transmission pose a threat to the 2022 Chagas disease elimination goal. Systematic integrated vector control and improved Chagas disease screening and treatment programs for congenital and vector-borne disease are needed to reach the elimination goal in regions with persistent vector infestation.
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Doença de Chagas/prevenção & controle , Controle de Insetos/métodos , Insetos Vetores/fisiologia , Triatoma/fisiologia , Adolescente , Adulto , Animais , Doença de Chagas/epidemiologia , Doença de Chagas/transmissão , Doença de Chagas/virologia , Feminino , Guatemala/epidemiologia , Humanos , Insetos Vetores/efeitos dos fármacos , Insetos Vetores/virologia , Inseticidas/farmacologia , Masculino , Triatoma/efeitos dos fármacos , Triatoma/virologia , Adulto JovemRESUMO
Parasites transmitted by insects must adapt to their vectors and reservoirs. Chagas disease, an American zoonosis caused by Trypanosoma cruzi, is transmitted by several species of triatomines. In Central America, Triatoma dimidiata is a widely dispersed vector found in sylvatic and domestic habitats, with distinct populations across the endemic region of Guatemala. Our aim was to test the strength of association between vector and parasite genetic divergence in domestic environments. Microsatellite (MS) loci were used to characterize parasites isolated from T. dimidiata (n=112) collected in domestic environments. Moderate genetic differentiation was observed between parasites north and south of the Motagua Valley, an ancient biogeographic barrier (FST 0.138, p=0.009). Slightly reduced genotypic diversity and increased heterozygosity in the north (Allelic richness (Ar)=1.00-6.05, FIS -0.03) compared to the south (Ar=1.47-6.30, FIS 0.022) suggest either a selective or demographic process during parasite dispersal. Based on parasite genotypes and geographic distribution, 15 vector specimens and their parasite isolates were selected for mitochondrial co-diversification analysis. Genetic variability and phylogenetic congruence were determined with mitochondrial DNA sequences (10 parasite maxicircle gene fragments and triatomine ND4+CYT b). A Mantel test as well as phylogenetic, network and principal coordinates analyses supported at least three T. dimidiata haplogroups separated by geographic distance across the Motagua Valley. Maxicircle sequences showed low T. cruzi genetic variability (π nucleotide diversity 0.00098) with no evidence of co-diversification with the vector, having multiple host switches across the valley. Sylvatic Didelphis marsupialis captured across the Motagua Valley were found to be infected with T. cruzi strains sharing MS genotypes with parasites isolated from domiciliated triatomines. The current parasite distribution in domestic environments can be explained by multiple parasite-host switches between vector populations and selection or bottleneck processes across the Motagua Valley, with a possible role for didelphids in domestic transmission.