Epidemiology and evolution of Zika virus in Minas Gerais, Southeast Brazil.

Autochthonous Zika virus (ZIKV) transmission in Brazil was first identified in April 2015 in Brazil, with the first ZIKV-associated microcephaly cases detected in October 2015. Despite efforts on understanding ZIKV transmission in Brazil, little is known about the virus epidemiology and genetic diversity in Minas Gerais (MG), the second most populous state in the country. We report molecular and genomic findings from the main public health laboratory in MG. Until January 2020, 26,817 ZIKV suspected infections and 86 congenital syndrome cases were reported in MG state. We tested 8552 ZIKV and microcephaly suspected cases. Ten genomes were generated on-site directly from clinical samples. A total of 1723 confirmed cases were detected in Minas Gerais, with two main epidemic waves; the first and larger epidemic wave peaked in March 2016, with the second smaller wave that peaked in March 2017. Dated molecular clock analysis revealed that multiple introductions occurred in Minas Gerais between 2014 and 2015, suggesting that the virus was circulating unnoticed for at least 16 months before the first confirmed laboratory case that we retrospectively identified in December 2015. Our findings highlight the importance of continued genomic surveillance strategies combined with traditional epidemiology to assist public health laboratories in monitoring and understanding the diversity of circulating arboviruses, which might help attenuate the public health impact of infectious diseases.

Biodistribution study and identification of inflammatory sites using nanocapsules labeled with (99m)Tc-HMPAO.

PURPOSE: To evaluate the ability of polymeric nanocapsules (NCs) radiolabeled with technetium-99m D,L-hexamethylpropyleneamine oxime (Tc-HMPAO) to identify inflammatory process in an experimental model. METHODS: NCs were prepared by interfacial deposition of preformed biodegradable polymer [poly (D,L-lactic acid) (PLA) and PLA-PEG (polyethyleneglycol)] followed by a solvent displacement. The size and homogeneity, and zeta potential of the NC preparations were determined in a Zetasizer by photon correlation spectroscopy and laser Doppler anemometry, respectively. The NCs radiolabeled with Tc-HMPAO were administered intravenously to Wistar male rats bearing a focal inflammation induced by subplantar injection of carrageenan in the right foot. At preestablished time intervals, the animals were anesthetized, tissues were removed and radioactivity was determined using an automatic scintillation apparatus. RESULTS: The average diameter calculated by photon correlation spectroscopy varied from 216 to 323 nm. The biodistribution studies showed a greater uptake of the PEG surface-modified Tc-HMPAO-NC by the inflamed paws when compared with the respective controls. There was no significant difference in the uptake of conventional Tc-HMPAO-NC and of free Tc-HMPAO by inflamed and control paws. These results indicate that the PLA-PEG Tc-NC showed a higher uptake in inflammation compared with free complex and may be useful as a radiotracer to identify these foci.

Biodistribution study and identification of inflammation sites using 99mTc-labelled stealth pH-sensitive liposomes.

PURPOSE: To investigate the biodistribution and the ability of stealth pH-sensitive liposomes radiolabelled with 99mTc to identify inflammatory regions in a rat focal inflammation model. METHODS: Preformed glutathione-containing stealth pH-sensitive liposomes were labelled with 99mTc-hexamethylpropylene amine oxime (99mTc-HMPAO). The 99mTc-HMPAO radiolabelled stealth pH-sensitive liposomes (99mTc-SpHL) were administered intravenously in Wistar male rats with inflammation induced by injection subplantar of carrageenan in the right foot. At pre-established time intervals the animals were anaesthetized and tissues were removed and analysed for 99mTc content using an automatic scintillation apparatus. Scintigraphic imaging was also performed after 2, 4 and 8 h of intravenous injection of 99mTc-SpHL. RESULTS: The 99mTc-SpHL was significantly taken up by the spleen (19.21+/-2.98%ID/g at 30 min post-injection). Low radioactivity levels were found in the liver, lungs, and kidney. Moreover, the 99mTc-SpHL uptake was significantly higher in the inflamed foot when compared to the respective control (0.386+/-0.059 and 0.215+/-0.018%ID/g at 2 h post-injection, respectively). As early as 30 min after administration of 99mTc-SpHL, the focus of inflammation could be visualized scintigraphically. The value of the inflammatory and non-inflammatory site radioactivity counting ratio was greater than 5. CONCLUSION: This result indicates that the 99mTc-SpHL presents a high tropism for inflammatory regions and may be useful as a radiopharmaceutical to identify these foci.