RESUMEN
The relationship between the level of antibodies in bulk tank milk (BTM) and the within-herd seroprevalence of Coxiella burnetii in cows was assessed. Blood from milking cows and BTM were sampled in 55 infected herds and tested using commercial enzyme-linked immunosorbent assay (ELISA) kits. The relationship between antibody levels and WHP, which was quantified using a general linear model, was only moderate (R(2)=0·15). Nevertheless, the lowest antibody level in BTM was associated with the lowest mean within-herd prevalence. The present finding indicates that ELISA applied to BTM could identify infected herds with quite low within-herd seroprevalence. For such herds, the vaccination of dairy cows as well as nulliparous heifers using a phase I vaccine could effectively prevent C. burnetii shedding.
Asunto(s)
Enfermedades de los Bovinos/epidemiología , Coxiella burnetii/aislamiento & purificación , Fiebre Q/veterinaria , Animales , Anticuerpos Antibacterianos/análisis , Anticuerpos Antibacterianos/sangre , Bovinos , Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/microbiología , Coxiella burnetii/inmunología , Industria Lechera , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Francia/epidemiología , Modelos Lineales , Leche/química , Leche/inmunología , Prevalencia , Fiebre Q/epidemiología , Fiebre Q/inmunología , Fiebre Q/microbiología , Estaciones del Año , Estudios SeroepidemiológicosRESUMEN
We described and quantified epidemiologic trends in dengue disease burden in 5 Asian countries (Indonesia, Thailand, Malaysia, Philippines, and Vietnam) and identified and estimated outbreaks impact over the last 3 decades. Dengue surveillance data from 1980 to 2010 were retrieved from DengueNet and from World Health Organization sources. Trends in incidence, mortality, and case fatality rate (CFR) were systematically analyzed using annual average percent change (AAPC), and the contribution of epidemic years identified over the observation period was quantified. Over the 30-year period, incidence increased in all countries (AAPC 1980-2010: 6.7% in Thailand, 10.4% in Vietnam, 12.0% in Indonesia, 18.1% in Malaysia, 24.4% in Philippines). Mortality also increased in Indonesia, Malaysia, and Philippines (AAPC: 6.8%, 7.0%, and 29.2%, respectively), but slightly decreased in Thailand and Vietnam (AAPC: -1.3% and -2.5%), and CFR decreased in all countries (AAPC: -4.2% to -8.3%). Epidemic years, despite representing less than a third of the observation period, contributed from 1 to 3 times more cases versus nonepidemic years. Implementation of more sensitive surveillance methods over the study period may have contributed to a reporting or ascertainment bias in some countries. Nonetheless, these data support the urgent need for novel, integrated, or otherwise effective dengue prevention and control tools and approaches.