RESUMEN
Human malaria is the most important vector-borne infectious disease in Iran. It remains focally endemic being restricted to almost 20 counties in three oriental provinces. As a result of control measures applied since 1988, these counties appear to be on the verge of eliminating malaria. Malaria elimination strategy has thus become the new goal in Iran. Malaria due to Plasmodium vivax, whose transmission is particularly hard to interrupt, accounts for nearly 90% of the cases. This study was thus undertaken to show malaria elimination trend from a hypo-endemic unstable active focus in southern Iran and to examine the role of prevailing climatic factors. This focus is now under elimination phase (Stratum III or annual parasitic index <1/1000 person/year). All malaria-positive cases were identified with active and passive procedures from 2003 to 2011. Although all ages were infected, more than half of the patients were in the higher than 20-year age group and a clear majority (77%) of them identified in the warmer months (May-October) of the year were positive with P. vivax parasites. The rate of falciparum to mixed infections was highest (1%) in the penultimate year. Case finding was negatively related to precipitation rate both annually and over the 9-year period and positively to ambient temperature in each year. Despite progress in the scale-up of its elimination, transmission of malaria remains active. This should be tackled by proactive case detection in specific hotspots of the study focus.
Asunto(s)
Clima , Control de Enfermedades Transmisibles/métodos , Erradicación de la Enfermedad , Enfermedades Endémicas , Malaria/epidemiología , Malaria/prevención & control , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Coinfección/epidemiología , Estudios Transversales , Femenino , Humanos , Lactante , Recién Nacido , Irán , Malaria/transmisión , Masculino , Persona de Mediana Edad , Plasmodium falciparum/aislamiento & purificación , Plasmodium vivax/aislamiento & purificación , Estaciones del Año , Adulto JovenRESUMEN
The toxicity of cypermethrin was determined in five different soft tick strains of Argas persicus Oken and Ornithodoros lahorensis Neuman by topical application method. The O. lahorensis Bij, O. lahorensis west O1, O. lahorensis Mesh, A. persicus Lor, A. persicus West Ap strains were collected from Bijar, Kurdistan province, Takab, Western Azerbaijan province, Meshkinshar, Ardebil province, Khoramabad, Lorestan province, Takab, Western Azerbaijan province of different areas of Islamic Republic of Iran, respectively during 2004 and 2005. In the topical application bioassay, the average LD50 of O. lahorensis Bij, West O1, Mesh and A. reflexus Lor and West AP strains were 0.03, 0.04, 1.7, 0.7 and 1.7 microg tick(-1), respectively and the steep slopes of dose-response curves indicated that the field population of these soft tick strains were homogenous in response to cypermethrin. Comparison of the resistance ratio of collected strains with susceptible strain showed a resistance ratio of 56.7 and 2.4-folds for cypermethrin in O. lahorensis Mesh and A. reflexus West Ap strains, whereas the O. lahorensis West O1 completely susceptible to cypermethrin.