Zoophilic feeding behaviour of phlebotomine sand flies in the endemic areas of cutaneous leishmaniasis of Sindh Province, Pakistan

Leishmania (Leishmania) major has been identified as the major causative agent of cutaneous leishmaniasis in Sindh Province of southern Pakistan. To make a rational approach for understanding the pathogen transmission cycles, the sand fly species and their natural blood meals in the endemic areas were examined. Total DNA was individually extracted from sand flies collected in four villages in Sindh Province. PCR-RFLP (restriction fragment length polymorphism) and sequence analysis of the 18S ribosomal RNA gene revealed that female sand flies identified were Sergentomyia clydei/Sergentomyia ghesquierei/Sergentomyia magna (68.6%), Sergentomyia dubia (17.1%), Phlebotomus papatasi (7.4%), Phlebotomus alexandri-like sand flies (3.4%) and Sergentomyia dentata (3.4%). PCR amplification of leishmanial kinetoplast DNA did not result in positive signals, suggesting that all 175 tested female sand flies were not infected with leishmanial parasites or contained undetectable levels of leishmanial DNA. Amplification and sequencing of the vertebrate cytochrome b gene in 28 blood-fed sand flies revealed that P. papatasi fed on cattle and wild rat whereas P. alexandri-like specimens fed on human, cattle, goat and dog. Although Sergentomyia sand flies are generally known to feed on cold-blooded animals, S. clydei, S. dubia and S. ghesquierei preferred humans, cattle, goat, sheep, buffalo, dog, donkey, wild rat and Indian gerbil. The epidemiological significance of the zoophilic feeding on various host species by Phlebotomus and Sergentomyia sand flies in Pakistan is further required to study for better understanding the zoonotic transmission of sand-fly-borne pathogens and for appropriate management of the vectors.     

Taeniasis among Refugees Living on Thailand–Myanmar Border, 2012

We tested refugee camp residents on the Thailand–Myanmar border for Taenia solium infection. Taeniasis prevalence was consistent with that for other disease-endemic regions, but seropositivity indicating T. solium taeniasis was rare. Seropositivity indicating cysticercosis was 5.5% in humans, and 3.2% in pigs. Corralling pigs and providing latrines may control transmission of these tapeworms within this camp.     

Premalignant lesions of cholangiocarcinoma: characteristics on ultrasonography and MRI

Background and objective

Cholangiocarcinoma (CCA) is an aggressive malignancy with high prevalence rate in Asia. The CCA premalignant lesions, including Biliary intraepithelial neoplasia (Bil-IN) and Intraductal papillary neoplasm of biliary tract (IPNB), share a common carcinogenesis; however, on imaging, patterns of presentation are different. Patterns and imaging characteristics on ultrasonography (US) and Magnetic resonance imaging (MRI) of both Bil-IN and IPNB are reported herein.

Methods

In this retrospective study of imaging findings in premalignant CCA, pathology-proven cases of Bil-IN and IPNB at Chulabhorn Hospital were analyzed. Demographics, locations of lesions, imaging characteristics of both Bil-IN and IPNB were assessed, compared, and described.

Results

Twenty-one premalignant lesions, 13 Bil-INs and 8 IPNBs, from 18 patients were included. Both Bil-IN and IPNB lesions were found more commonly at the right than left intrahepatic ducts (66.7% vs. 33.3%), and had more peripheral than central locations (85.7% vs. 14.3%). On US, Bil-IN commonly presented as focal bile duct dilatation (76.9%), whereas IPNB was more variable with hyperechoic nodules (37.5%), focal bile duct dilatation (37.5%), and diffuse bile duct dilatation with intraductal nodules (25%). On MRI, focal bile duct dilatation and nonfunctioning bile excretion are the most sensitive findings with sensitivities in the range of 84.6% to 100%. The presence of intraductal nodules and connection to the biliary system are findings that were significantly different between IPNB and Bil-IN, 62.5% versus 7.7% (p = 0.014) and 75% versus 15.4% (p = 0.018), respectively.

Conclusions

Premalignant lesions of CCA, including Bil-IN and IPNB, have different imaging presentations. Knowledge of imaging presentations may improve early detection and increase confidence in diagnosis.