ABSTRACT
Descrevem-se 24 surtos de tristeza parasitária bovina no sertão paraibano, sendo 18 de anaplasmose por Anaplasma margimale, dois de babesiose por Babesia bigemina, dois por Babesia não identificada e dois por infecção mista de A. marginale e Babesia sp. Os surtos ocorreram entre agosto de 2007 a outubro de 2009, porém, com uma concentração dos surtos no final do período chuvoso e início do período seco de cada ano, sendo 22 em animais adultos e dois em bezerros de aproximadamente 11 meses. Dois surtos ocorreram em bovinos da raça Nelore, um em animais da raça Gir e os 21 restantes ocorreram em animais das raças Holandês, Pardo Suiço e mestiços das mesmas com zebuínos. Conclui-se que no sertão da Paraíba há áreas de instabilidade enzoótica, ocorrendo surtos de tristeza no final da época de chuvas, principalmente nas áreas de planaltos e serras da região da Borborema e em áreas úmidas como a Bacia do Rio do Peixe, Rio Piranhas e Rio Espinharas em que há a formação de microclimas favoráveis à sobrevivência do carrapato.
Twenty four outbreaks of cattle tick fever are reported in the semiarid region of Paraiba known as Sertão. Eighteen outbreaks were caused by Anaplasma. marginale, two by Babesia bigemina, and two by mixed infection of A. marginale and Babesia sp. In other two outbreaks of babesiosis the species of Babesia was not identified. Outbreaks occurred from August 2007 to October 2009, however with a concentration of the outbreaks at the end of the rainy period and beginning of the dry period in each year. Twenty two outbreaks affected adult cattle and two affected calves approximately 11 months-old. Three outbreaks affected Bos taurus indicus cattle, of the Nelore and Gir breeds. In 21 outbreaks Holstein, Brown Swiss and crossbred of these breeds with Bos taurus indicus cattle were affected. It is concluded that in the sertão of Paraíba there are areas of enzootic instability for cattle tick fever occurring outbreaks at the end of the rainy season, mainly in hilly areas of the Borborema region, and in wet areas of some river basins, including Rio do Peixe, Rio Piranhas and Rio Espinharas.
Subject(s)
Animals , Cattle/classification , Parasites/parasitology , Anaplasma marginale/pathogenicity , Babesia/microbiologyABSTRACT
Anaplasmosis belongs to the complex of several tick-borne diseases and can cause diseases in the livestock with high economical losses. Cattle that recover from acute infection become carriers and the parasite can persist most probably for the lifetime in the blood. The aim of the present study was the determination of the persistently infected cattle in a region of Iran with the previous history of acute anaplasmosis. One hundred and fifty blood samples and corresponding blood smears of cattle without any signs of diseases were prepared from a region in Isfahan/ Iran with the previous history of acute anaplasmosis from March 2007 to July 2007 for cross sectional study of carriers of Anaplasma. The blood smears were first screened by Giemsa staining, the extracted DNA from blood cells were analyzed by Anaplasma marginale specific nested PCR, and PCR-RFLP using primers derived from 16S rRNA gene and restriction endonuclease Bst 1107 I. Anaplasma like structures could be identified in the limited amount of erythrocytes of 75 blood smears. In these samples, the percentage of erythrocytes harboring Anaplasma like structures varied from 10[-3]% to 10[-2]%. Nested-PCR and PCR-RFLP analysis showed 58 A. marginale positive cases within 75 Anaplasma suspected blood samples. In 150 total blood samples, 50% were A. marinale positive. Our results revealed that the traditional Giemsa staining method is not applicable for the determination of the persistently infected cattle. In addition, the results showed that the carrier animals must be widespread in the Anaplasma endemic areas in Iran