INTRODUCCIÓN
El dengue es una enfermedad febril que afecta a la región de las Américas. En Honduras, en los últimos cinco años se han declarado dos emergencias sanitarias por esta enfermedad, relacionadas con condiciones socioeconómicas y climáticas que facilitan la transmisión del virus. Por ello, se necesitan estrategias innovadoras e integrales para prevenirlo. El World Mosquito Program desarrolló un método basado en la introducción de la bacteria Wolbachia en poblaciones de mosquitos Ae. aegypti. Wolbachia actúa reduciendo la capacidad de Ae. aegypti para transmitir arbovirus a través de la restricción de la infección y replicación viral en los tejidos del mosquito. Médicos Sin Fronteras realizó la implementación del método, con especial énfasis en la aceptación y participación comunitaria, como parte integral del control vectorial y prevención de dengue en la comunidad de El Manchén, Tegucigalpa, Honduras.
OBJETIVOS
Los objetivos del estudio fueron evaluar la introgresión de Wolbachia en poblaciones locales de mosquitos Ae. aegypti en la zona de intervención, el impacto asociado en la incidencia de dengue, y la aceptación y participación comunitaria en la implementación del método Wolbachia.
METODOLOGÍA
Adoptando un enfoque de pacientes y población como socios (PPP), Médicos sin Fronteras colaboró con 51 voluntarios comunitarios para implementar el método Wolbachia en El Manchén, Tegucigalpa. En conjunto, los motoristas de MSF y los voluntarios comunitarios liberaron 8.3 millones de mosquitos desde agosto 2023 a febrero 2024 (26 semanas). La introgresión fue evaluada capturando zancudos de 49 puntos aleatorios en la comunidad, los cuales después fueron examinados para detectar las proteínas de superficie de Wolbachia, con la técnica de reacción en cadena de la polimerasa por el Laboratorio de Investigaciones en Microbiología de la Universidad Nacional Autónoma de Honduras. Las evaluaciones se realizaron quincenalmente durante el periodo de liberación, y trimestralmente después de terminar con las liberaciones. Para entender la perspectiva de la comunidad, se realizó una encuesta preliberaciones y post-liberaciones que evaluó aspectos socioeconómicos, conocimientos y aceptación sobre el método. Además, se realizaron 13 grupos de discusión focales con 161 miembros de la población. Los resultados de los procedimientos de recolección cualitativos fueron analizados en NVIVO siguiendo ejes temáticos relacionados con los factores que median la aceptabilidad y la experiencia de los habitantes con la implementación de la estrategia.
RESULTADOS
Se observó una tendencia creciente en la prevalencia de mosquitos Ae. aegypti portadores de Wolbachia. Los resultados preliminares durante las liberaciones muestran porcentajes progresivos de infección de Wolbachia: 16.3%, 30.52%, 62.45%, 72.53%, hasta febrero 2024 con 82.79%. Posterior a las liberaciones, se documentó una reducción inicial y esperada (65.18% en abril 2024 y 57.55% en junio 2024), seguido por un crecimiento en septiembre 2024 a 85.27%. Las encuestas de aceptabilidad, entrevistas, y grupos focales demostraron una alta aceptabilidad de Wolbachia. Ambos antes y después de la intervención, >90% de encuestados estuvieron de acuerdo con las liberaciones implementadas por MSF y la secretaria de Salud. Un aumento en las picaduras fue el comentario negativo más común. En los grupos focales las principales preocupaciones fueron el aumento de mosquitos o de casos de dengue por las liberaciones de mosquitos, además de la inocuidad de Wolbachia. Sin embargo, los habitantes de El Manchén señalaron una perspectiva positiva de la estrategia para el control vectorial. Desafíos de implementación incluyeron el escepticismo de la comunidad, la inseguridad, y factores ambientales que afectaron los huevos. Beneficios indirectos del trabajo conjunto con la comunidad incluyen 25 iniciativas nuevas de la comunidad para el control de vectores, a partir de la adopción del enfoque PPP y apoyo por MSF.
CONCLUSIONES Y RECOMENDACIONES
Los resultados sugieren que la implementación de la Wolbachia contra el dengue sea factible y aceptable en Tegucigalpa, Honduras, con el apoyo de la comunidad para la implementación de la estrategia. El establecimiento aparente de Wolbachia sugiere que pueda tener un impacto positivo en la incidencia de dengue. Se continuará monitoreando el establecimiento y las tasas de incidencia de arbovirus a través de un análisis de series temporales interrumpidas con datos históricos y prevalencias actuales de dengue. Se sugiere mantener mecanismos de prevención de arbovirus integrales.
The 2014 West Africa Ebola outbreak underlined inadequacies of current personal protective equipment (PPE), such as being uncomfortable and hot, causing excessive sweating and rapid exhaustion, and limiting interactions between health workers and patients. The smartPPE development project responded to the urgent need for a more comfortable, simpler, and sustainable PPE solution for filovirus-outbreak front-line workers. A one- piece, reusable smartPPE with ventilation system was developed to address these challenges. We assessed ease-of-use, comfort, functionality, and perceived doffing-safety of the smartPPE prototype compared with currently used PPE (current-PPE) under simulated field conditions.
METHODS
In June 2023, we conducted a mixed-methods crossover usability study in a controlled high-heat/high-humidity indoor site in Brindisi, Italy. Ten test users (three female, seven with filovirus-front-line experience) assessed smartPPE and current- PPE in four guided sessions covering donning, (emergency) doffing, clinical tasks, and heavy physical WATSAN activities. User feedback was collected through structured questionnaires. Temperature, humidity, session duration, and vital signs were measured, and perceived exertion was assessed using Borg- scores (scale 6–20).
RESULTS
Median temperature and humidity were higher inside current- PPE than inside smartPPE (difference: 2.3°C [IQR 1.8–3.0] and 12.6 percentage points [8.8–19.6], respectively). Users endured heavy work sessions for significantly longer in smartPPE than in current-PPE (80.0 min [IQR 75–84] vs 49.5 min [45–56]). Median increases in body temperature (1.1°C [IQR 0.7–1.6] vs 0.7°C [0.3–0.9]; p<0.001) and respiratory rate (3.5 rpm [1–5] vs 1.5 rpm [0–3]; p=0.034), and reductions in O2 saturation (–2% [–5 to –1] vs –1.5% [–3 to 0]; p=0.027) were higher with current-PPE than with smartPPE. Peripheral vision was similarly rated, but hearing was compromised with smartPPE at ≥5 m. Median exertion- scores were lower for smartPPE (clinical tasks 8.5 [IQR 7–11] vs 15.5 [14–16] p<0.01; heavy physical activities 14 [13–17] vs 18 [17–20] p=0.035). All users preferred smartPPE for overall and thermal comfort, breathing, and doffing-safety; nine (90%) favoured it for non-verbal communication, eight (80%) for vision or longer-interval heavy WATSAN activities, six (60%) for longer- interval patient care, six (60%) for short-term clinical activities, and six (60%) for emergency doffing. Reported concerns were airflow obstruction while bending, hearing difficulties attributed to ventilation noise, and adjustments for headgear, ventilation, and suit fitting.
CONCLUSION
Test users confirmed the usability of smartPPE and favoured it, especially for doffing-safety, longer-interval clinical or physical work, and improved non-verbal interactions, whereas hearing was challenged by the ventilation. Adjustments are currently underway before design freeze. Stakeholder commitment will be crucial to ensure production at scale.
The risk of cholera outbreaks spreading rapidly and extensively is substantial. Case-area targeted interventions (CATI) are based on the premise that early detection can trigger a rapid, localised response in the high-risk radius around case-households to reduce transmission sufficiently to extinguish the outbreak or reduce its spread, as opposed to relying on resource-intensive mass interventions. Current evidence supports intervention in a high-risk spatiotemporal zone of up to 200 m around case- households for 5 days after case presentation. Médecins Sans Frontières (MSF) started delivering CATI to people living within these high-risk rings during outbreaks in the Democratic Republic of the Congo in April 2022. We present the results of a prospective observational study designed to evaluate the CATI strategy, measuring effectiveness, feasibility, timeliness, and resource requirements, and we extract operational learnings.
METHODS
Between April 2022 and April 2023, MSF delivered the holistic CATI package in five cholera-affected regions. The package incorporated key interventions combining household-level water, sanitation, and hygiene measures, health promotion, antibiotic chemoprophylaxis, and single-dose oral cholera vaccination (OCV). We conducted a survey in each ring roughly 3 weeks after the intervention to estimate coverage and uptake of the different components. We measured effectiveness by comparing cholera incidence in the first 30 days between rings with different delays from primary case presentation to CATI implementation, using a Bayesian regression model and adjusting for covariates such as population density, age, and access to water and sanitation.
RESULTS
During the study, four MSF operational sections implemented 118 CATI rings in five sites. The median number of households per ring was 70, the median OCV coverage was 85%, and the median time from presentation of the primary case to CATI implementation and to vaccination was 2 days and 3 days, respectively. These characteristics varied widely across sites and between rings. No secondary cases were observed in 81 (78%) of 104 rings included in the analysis, and we noted a (non- significant) decreasing trend in the number of secondary cases with decreasing delay to CATI implementation, e.g. 1.3 cases [95% CrI 0.01–4.9] for CATI implementation starting within 5 days from primary case presentation, and 0.5 cases [0.03–2.0] for CATI starting within 2 days.
CONCLUSION
Our results show that rapid implementation of CATI with vaccination is feasible in complex contexts. The number of secondary cases was low when CATI was implemented promptly. This highly targeted approach may be an effective strategy to quickly protect people most at risk and is resource- efficient if implemented early to extinguish localised outbreaks before they require mass interventions.
Ebola viruses (EBOVs) are primarily transmitted by contact with infected body fluids. Ebola treatment centers (ETCs) contain areas that are exposed to body fluids through the care of patients suspected or confirmed to have EBOV disease. There are limited data documenting which areas/fomites within ETCs pose a risk for potential transmission. This study conducted environmental surveillance in 2 ETCs in Freetown, Sierra Leone, during the 2014–2016 West African Ebola outbreak.
METHODS
ETCs were surveyed over a 3-week period. Sites to be swabbed were identified with input from field personnel. Swab samples were collected and tested for the presence of EBOV RNA. Ebola-positive body fluid-impregnated cotton pads were serially sampled.
RESULTS
General areas of both ETCs were negative for EBOV RNA. The immediate vicinity of patients was the area most likely to be positive for EBOV RNA. Personal protective equipment became positive during patient care, but chlorine solution washes rendered them negative.
CONCLUSIONS
Personal protective equipment and patient environs do become positive for EBOV RNA, but careful attention to decontamination seems to remove it. EBOV RNA was not detected in general ward spaces. Careful attention to decontamination protocols seems to be important in minimizing the presence of EBOV RNA within ETC wards.