Chikungunya: important lessons from the Jamaican experience / Chikungunya: enseñanzas importantes de la experiencia jamaiquina

ABSTRACT Objectives To describe the clinical presentation of chikungunya virus (CHIKV) illness in adults during the 2014 outbreak in Jamaica and to determine the predictive value of the case definition. Methods A cross-sectional study was conducted using clinical data from suspected cases of CHIKV that were reported to the Ministry of Health in April - December 2014. In addition, charts were reviewed of all individuals over 15 years of age with suspected CHIKV based on a diagnosis of CHIKV or "acute viral illness" that presented to four major health centers in Jamaica during the week prior to and the peak week of the epidemic. Data abstracted from these charts using a modified CHIKV Case Investigation Form included demographics, clinical findings, and laboratory tests. Results In 2014, the Ministry of Health of Jamaica received 4 447 notifications of CHIKV infection. PCR testing was conducted on 137 suspected CHIKV cases (56 men and 81 women; median age 28 years) and was positive for 89 (65%) persons. In all, 205 health charts were identified that met the selection criteria (51 men and 154 women, median age 43 years). The most commonly reported symptoms were arthralgia (86%) and fever (76%). Of those who met the epidemiologic case definition for CHIKV as defined by the Pan American Health Organization, only 34% had this diagnosis recorded. Acute viral illness was the most frequently recorded diagnosis (n = 79; 58%). Conclusions Broader case definitions for acute CHIKV illness may be needed to identify suspected cases during an outbreak. Standardized data collection forms and validation of case definitions may be useful for future outbreaks.

RESUMEN Objetivo Describir el cuadro clínico de la infección por el virus del chikungunya (CHIKV) en los adultos durante el brote del 2014 en Jamaica y determinar el valor predictivo de la definición de caso. Métodos Se realizó un estudio transversal con los datos clínicos de los presuntos casos de CHIKV que se notificaron al Ministerio de Salud entre abril y diciembre del 2014. Además, se examinaron las historias clínicas de todos los mayores de 15 años con presunto cuadro de CHIKV, es decir con diagnóstico de CHIKV o de "virosis aguda", que acudieron a cuatro grandes centros de salud de Jamaica durante la semana de máxima incidencia de la epidemia y la semana anterior. De las historias se extrajo, mediante un formulario modificado para el estudio de casos de CHIKV, la siguiente información: datos demográficos, resultados clínicos y análisis de laboratorio. Resultados En el 2014, el Ministerio de Salud de Jamaica recibió 4 447 notificaciones de infección por el CHIKV. Se realizó la RCP de 137 presuntos casos de CHIKV (56 varones y 81 mujeres; mediana de edad de 28 años), que dio positivo en 89 personas (el 65%). En total, se encontraron 205 historias clínicas que reunían los criterios de selección (51 varones y 154 mujeres; mediana de edad de 43 años). Los síntomas comunicados con mayor frecuencia fueron las artralgias (86%) y la fiebre (76%). De los que se ajustaron a la definición epidemiológica de caso de CHIKV de la Organización Panamericana de la Salud, solo en el 34% se había registrado ese diagnóstico. La virosis aguda fue el diagnóstico registrado con mayor frecuencia (n = 79; 58%). Conclusiones Es posible que se necesiten definiciones de caso más amplias para la infección aguda por CHIKV a fin de identificar los casos sospechosos durante un brote. Los formularios estandarizados para la recopilación de datos y la validación de las definiciones quizá resulten útiles para otros brotes en el futuro.

Magnitude, Distribution, and Estimated Level of Underreporting of Acute Gastroenteritis in Jamaica.

Jamaica is the third largest island in the Caribbean. The epidemiology of acute gastroenteritis (AGE) is important to Jamaica, particularly in the areas of health, tourism, and because of the potential impact on the local workforce and the economy. Data collected by the National Surveillance Unit on the prevalence of AGE transmitted by food are not accurate. To determine the true magnitude, risk factors, and the extent of underreporting of AGE in Jamaica, we conducted a cross-sectional, population-based retrospective survey during the periods of 21 February–7 March and 14-27 June 2009, corresponding to high- and low-AGE season respectively. Of the total 1,920 persons selected randomly by a multistage cluster-sampling process, 1,264 responded (response rate 65.8%). Trained interviewers administered a standardized, validated questionnaire during face-to-face interviews. The overall prevalence of self-reported AGE was 4.0% (95% CI 2.9-5.1) at a rate of 0.5 episodes/per person-year. The highest monthly prevalence of AGE (14.6%) was found among the 1-4 year(s) age-group and the lowest (2.1%) among the 25-44 years age-group. Of the 18 cases (36%) who sought medical care, 11% were hospitalized, 33% were treated with antibiotics, and 66.7% received oral rehydration fluids. Only 2 cases who sought medical care reportedly submitted stool specimens. The mean duration of diarrhoea was 3.1 days, which resulted in a mean loss of 4 productive days, with over half of the cases requiring someone to care for them. The burden of syndromic AGE for 2009 was extrapolated to be 122,711 cases, showing an underreporting factor of 58.9. For every laboratory-confirmed AGE case, it was estimated that 383 more cases were occurring in the population. This research confirms that the prevalence of AGE is underreported in Jamaica and not being adequately detected by the current surveillance system. The components of the integrated surveillance system for AGE in Jamaica, particularly the laboratory aspect, need to be strengthened.