ABSTRACT
Background: Human and animal trichinosis has been recorded in Chile since the late XIX century and is irregularly distributed along the country. From high rates of infection in the early 1900, the frequency of this parasitosis in man has progressively decreased. Aim: To describe and discuss the epidemiological situation of trichinosis in Chile during the decade 1991 - 2000. Material and methods: Human infection was assessed using annual incidence and lethality reports provided by the Ministry of Health, periodic photostrichinoscopies in corpses of non selected individuals autopsied at the Medico Legal Service and periodic national serologic surveys. The advise of one of the authors in an epidemic that occurred in 1999 in the VIII Region was also used. Animal infection was assessed using the annual prevalence of infection in pigs slaughtered in abattoirs, furnished by the Ministry of Health. Results: A total of 631 clinical cases with 4 deaths (0.6 percent) was recorded. A decline in the incidence, from 0.7 x 100,000 in 1991 to 0.2 x 100,000 in 2000 was recorded. The higher frequency of the parasitosis was observed in the Metropolitan, VI, VIII and X regions. Although human trichinosis has been observed in all seasons, its frequency increases in close relation with the higher pork consumption in cold seasons (45.8 percent in winter and 37.5 percent in spring). There has been a decrease of infection rates in pigs from 0.17 percento in 1991 to 0.04 percento in 1998 - 2000. Conclusions: The incidence and prevalence of trichinosis shows a constant decline in Chile. Considering the geographical characteristics of Chile, it is possible that an undetermined number of pigs are home reared and butchered without veterinary control, constituting an important source of human trichinosis
Subject(s)
Humans , Male , Adolescent , Adult , Female , Infant, Newborn , Infant , Child, Preschool , Middle Aged , Trichinellosis , Disease Outbreaks , Trichinella spiralis , Swine , Trichinellosis , Chile , Incidence , Prevalence , Residence Characteristics/statistics & numerical dataABSTRACT
El primer caso de síndrome pulmonar por hantavirus (SPH) registrado en Chile determinó la necesidad de desarrollar investigaciones en las poblaciones de roedores tendientes a identificar el reservorio de hantavirus en Chile, su distribución y hábitat, así como la distribución del hantavirus dentro de las poblaciones del reservorio. Entre 1996 y 1999 se desarrollaron estudios de reservorios desde la Región Metropolitana a la Región de Aysén. El aislamiento del virus variedad, Andes, a partir del Oligorizomys longicaudatus, permite afirmar que, al igual que en la zona sur de Argentina, éste es el reservorio de hantavirus en Chile. La especie Abrothrix longipilis también resulto positiva al aislamiento viral, por lo que estudios posteriores deberán determinar si éste es otro reservorio del virus en el país. Otras tres especies de roedores silvestres resultaron seropositivas al virus lo que se explicaría como una infección transitoria a partir del reservorio. Se pudo constatar la presencia del reservorio en todas las regiones muestreadas, aunque las densidades poblacionales de esta especie son mayores en la zona sur. Existe circulación de hantavirus en toda el área de distribución del reservorio
Subject(s)
Animals , Mice , Hantavirus Infections/epidemiology , Orthohantavirus/isolation & purification , Rodentia/virology , Chile/epidemiology , Disease Reservoirs/classification , Residence Characteristics , Ecosystem , Orthohantavirus/pathogenicityABSTRACT
Considerando el hábitat principal del reservorio y las vías de transmisión del SPH, las medidas de prevención deben estar orientadas a evitar el contacto de las personas con los roedores y sus excretas, especialmente en las áreas rurales