Dirofilaria immitis infestation in imported police (K-9) dogs in Iraq: clinicopathological and molecular investigations study / Infecção por Dirofilaria immitis em cães policiais importados no Iraque: estudo clínico-patológico e de investigações moleculares

Dirofilaria immitis, the cause of heartworm infestation (HWI) or dirofilariasis, affects members of the Canidae and remains a worldwide clinical problem. In Iraq, dirofilariasis was believed absent until 2009, when the Karbala Governorate was reported as an endemic area for canine dirofilariasis. Consequently, this study intended to investigate the occurrence of Dirofilaria immitis in police dogs in one police academy in Iraq and to study the gross and histopathological changes in 5 dead dogs, as well as to identify the species of the causative parasite using PCR technique. Thirty-nine police dogs, aged between 6 months and 12 years were included in this study. For the microfilariae investigation, 5 ml blood samples were collected from all dogs in EDTA tubes and examined by Knott's method. The systemic necropsy performed in five dead dogs showed severe clinical signs of dirofilariasis and tissue specimens were sent for routine histopathological processing. For the molecular analysis, adult worms of the detected Dirofilaria spp. were used for DNA extraction and amplification of the cox1 gene. Fifteen of 39 (38.46%) dogs were diagnosed with moderate to severe microfilariasis. The dead dogs revealed typical severe clinical signs of dirofilariasis. Moreover, typical gross and histopathological changes were also seen, accompanied by generalized thromboembolic lesions, suggesting the occurrence of the caval syndrome. The PCR investigation confirmed that D. immitis was the species present in Iraq. In conclusion, this study establishes that Iraq is a newly reported endemic area for dirofilariasis. Moreover, the infestation occurring in these cases most probably happened inside Iraq. The authors recommend doing further epidemiological studies concerning the occurrence of D. immitis in local dogs as well as in the imported dogs in all Iraqi governorates to better understand the epidemiological map of this disease and to introduce an active treatment and preventive program. Awareness and education regarding this disease should be provided to the veterinarians, dog guiders and people in direct contact with dogs, as this disease is one of the important zoonotic diseases.(AU)

A Dirofilaria immitis, causadora da infestação pelo verme do coração (IVC) ou dirofilariose afeta os membros da família Canidae e ainda é um problema clínico mundial. Até o ano de 2009, acreditava-se que o Iraque fosse livre da dirofilariose, porém nessa ocasião a governadoria de Kerbala foi relatada como uma área endêmica de dirofilariose. Assim, o presente trabalho foi realizado para investigar a ocorrência da Dirofilaria immitis em cães policiais em uma academia de polícia do Iraque, estudar as alterações macroscópicas e histopatológicas em cinco cães mortos, bem como, identificar as espécies do parasita causador com o emprego da técnida de PCR. Trinta e nove cães policiais com 6 meses a 12 anos de idade foram incluídos no estudo. Amostras de sangue de cinco mililitros foram colhidas por animal, em tubos com EDTA e foram examinadas pelo método de Knott. A necropsia sistêmica foi realizada em cinco cães que haviam apresentado sinais clínicos severos de dirofilariose e espécimens dos seus tecidos foram enviados para o processamento histopatológico de rotina. Para a análise molecular dos vermes adultos de Dirofilaria spp, foi empregada a extração do DNA e a amplificação do gene cox1. Quinze de 39(38,46%) cães foram diagnosticados com uma microfilariase variável de moderada para severa. As alterações macroscópicas e histopatológicas foram acompanhadas por lesões generalizadas tromboembólicas sugestivas da ocorrência da síndrome da veia cava. A investigação de PCR confirmou que a D.immitisera a espécie presente no Iraque. A conclusão do estudo estabeleceu que o Iraque deve passar a ser considerado como uma nova área endêmica da dirofilariose. Além da infestação registrada nos casos descritos é provável que ela também esteja presente em outras regiões do Iraque. Os autores recomendam a realização de estudos epidemiológicos para investigar a ocorrência de D.immitis tanto nos cães locais bem como em cães importados em todas as governadorias do Iraque, para ser construído o mapa epidemiológico da distribuição da doença e implantadas as ações de tratamento e de um progrma preventivo. Ações de educação em saúde sobre a doença deverão ser dirigidas para os veterinários, tratadores de cães e para pessoas em geral que tenham contato com os cães, pois esta doença é uma importante zoonose.(AU)

Prediction of villages at risk for filariasis transmission in the nile delta using remote sensing and geographic information system technologies

Remote sensing and geographic information system [GIS] technologies were used to discriminate between 130 villages in the Nile Delta, at high and low risk for filariasis, as defined by microfilarial prevalence. Landsat Thematic Mapper [TM] data were digitally processed to generate a map of land-cover as well as spectral indices such as NDVI and moisture index. A Tasseled Cap transformation was also carried out on the TM data which produced 3 more indices [brightness, greenness and wetness]. GIS functions were used to extract information on land-cover and spectral indices within 1 km buffers around the study villages. The relationship between satellite data and prevalence was investigated using discriminant analysis. The analysis indicated that the most important landscape elements associated with prevalence were water and marginal vegetation, while wetness and moisture index were the most important indices. Discriminant functions generated for these variables were able to predict correctly 80% and 74% of high and low prevalence villages, respectively, with an overall accuracy of 77%. The present approach provided a promising tool for regional filariasis surveillance and helps direct control efforts

Spatial analysis of lymphatic filariasis distribution in the nile delta in relation to some environmental variables using geographic information system technology

Geographic information system [GIS] was used to analyze the spatial distribution of filariasis in the Nile Delta. The study involved 201 villages belonging to Giza, Qalyoubia, Monoufia, Gharbia, and Daqahlia governorates. Villages with similar microfilarial [mf] prevalence rates were observed to cluster within 1-2 km distance, then clustering started to decrease significantly with distance up to 5 km [Pearson correlation coefficient = -0.98]. The likelihood of negative and high prevalence villages being contiguous was very low [1.8%, n = 612 village-pairs] indicating homogeneity in disease processes within the defined spatial scales. Of the villages located within 2 km from the main Nile branches [n = 46], 95% exhibited low prevalence. In addition, the spatial pattern of mf prevalence was shown to be negatively associated with annual rainfall and relative humidity, while it was positively associated with annual daily temperature. Average mf prevalence in warmer, relatively drier areas receiving 25 mm of rain was significantly higher [3.9%] than that in less warmer but more humid areas receiving 50 mm of rain [1.6%] [P <0.0001]. Based on the results of the present study, GIS was used to generate a filariasis risk map that could be used by health authorities to efficiently direct surveillance and control efforts. This investigation identified some of the factors underlying filariasis spatial pattern, quantified clustering and demonstrated the potential of GIS application in vector-borne disease epidemiology

Effect of two single doses of ivermectin in treatment of asymptomatic bancroftian filariasis in two villages in the Nile delta, Egypt

To evaluate the efficacy and longitudinal effect of two single [100 mug/kg] doses of ivermectin, 3 months apart, 240 asymptomatic male subjects from 2 endemic Egyptian villages were enrolled in a one- year double-blind study. Subjects aged 15 - 55 years were randomly assigned to placebo [40] or ivermectin [200]. Microfilaria [MF] density in 1 ml blood was measured by membrane filtration before and every 3 months after treatment. Initial mean MF density was 462 [range 14 - 2869/ml]. Clinical examination performed daily for 3 days after each treatment revealed brief, mild side effects [fever, headache, weakness, nausea, and epigastric pain] with no adverse physical or laboratory findings. Three months after initial dose, 31% of MF counts had completely cleared, in the remaining, mean MF density was 11.0 [2.4% of pretreatment level]. At 3, 6 and 9 months after the second Dose, there was complete MF clearance in 60%, 45% and 47%. In those who still infected, MF densities were 1.7, 4.6 and 6.1% of the pretreatment level. Therefore, treatment with 2 doses of ivermectin reduced microfilaremia, without inducing severe side effects. Prolonged suppression of microfilaremia may indicate an effect of ivermectin on the adult worms and may reduce the potential for MF acquisition by mosquitos, reducing transmission of lymphatic filariasis. It was concluded that ivermectin is a useful drug for public health measure, including asymptomatic filariasis patients

Study of filariasis in Qualioubia governorate, Egypt

Seven hundred and fifty individuals were chosen randomly from five centers known to be endemic for filariasis in Qualubiya Governorate. These were Benha, Tokh, Qalyub, EI Khanka and Shebin EI-Kanater centers. Case sheet was designed to cover personal, present and past histories for filariasis. Thorough clinical examination was performed. Blood samples [taken at 10 p.m. -2 a.m.] were examined by wet preparation and counting chamber techinque. Microfilariae were detected in 68 cases [9.07%]. There was no statistical significance between positive cases as regards sex [p > 0.05] but there was high significance as regards age [p < 0.01]. The range of density of microfilariae in 1 ml venous blood was 10.7 - 34.18 [mean 22.5 /ml] and in 5 ml 47-176 [mean 111.5/5ml]. Fifty four cases [7.2%] showed clinical manifestations for filariasis [11 microfilaraemic and 43 amicrofilaraemic] in the form of limb itching, limb swelling, elephantiasis in one or more limb, hydrocele and chyluria. There was positive correlation between percentage of clinical cases and microfilaraemia [P<0.05] and no correlation between it and density of micro filariae [P<0.05]

Survival and infectivity of Brugia malayi microfilariae after cryopreservation.

Methods were studied for the cryopreservation of microfilariae of periodic Brugia malayi. RPMI-1640 tissue culture medium containing 6% dimethyl sulfoxide (DMSO) and 15% newborn calf serum was used as cryoprotectant. Samples were frozen slowly in the vapor phase of liquid nitrogen prior to emersion in liquid nitrogen (-196 degrees C). The freezing rate was -0.5 to -1.0 degrees C per minute, microfilariae remained viable for as long as, 212 and 375 days, survival rates were 94 to 98% and they were infective to Aedes togoi mosquitos. The infective larvae (L3) were obtained for 10-11 days after feeding at 28 degrees C room-temperature and the infection rate of L3 in test mosquitos was 22.4-30.6%. All DMSO should be removed from the freezing medium to restore microfilariae activity after freezing.