Killer cell immunoglobulin-like receptors (KIR) form a group of regulatory molecules that specifically recognise human leukocyte antigen (HLA) class I molecules, modulating the cytolytic activity of natural killer cells. The purpose of this study was to investigate the influence of KIR genes and their class I HLA ligands in susceptibility to dengue fever in a population from southern Brazil through a case-control study. One hundred four subjects with confirmed diagnoses of dengue participated in this study, along with a control group of 172 individuals from the same geographic area. HLA and KIR genotyping was performed by polymerase chain reaction with sequence-specific oligonucleotide probes (PCR-SSOP) and with sequence-specific primer (PCR-SSP) techniques, respectively. Data analysis showed significant differences for the KIR2DS1 (54.8% vs 40.7%, P = 0.03), KIR2DS5 (50.0% vs 36.0%, P = 0.03) and KIR2DL5 (76.0% vs 56.4%, P = 0.001) genes. With regard to KIR-ligand pairs, positive associations with dengue were observed in KIR3DS1-Bw4 (45.2% vs 29.7%, P = 0.01), KIR3DL1-Bw4 (80.7% vs 65.1%, P < 0.001), KIR2DL1-C2 (75.0% vs 62.2%, P = 0.03) and KIR2DS1-C2 (40.4% vs 25.6%, P = 0.01) interactions, and a negative association in KIR2DL3-C1/C1 (18.2% vs 33.1%, P = 0.01). Furthermore, the analysis of KIR haplogroups showed a possible protective factor against dengue fever in individuals with the AA genotype. Taken together, these results suggest the existence of genetic predisposition to dengue fever in the population from southern Brazil.

INTRODUCTION: Leptospirosis is a zoonotic disease, the primary hosts of which are wild, synanthropic, and household animals. Humans behave as terminal and accidental hosts. The prevalence of leptospirosis depends on carrier animals that disseminate the agent, on the environmental survival of this agent, and on the contact of susceptible individuals. Each serovar has one or more hosts with different adaptation levels. The focuses of leptospirosis are infected, sick, and asymptomatic animals, which are considered to be sources of environmental infection. This study aimed to determine the risk areas for leptospiral infection in stray dogs and patients diagnosed with leptospirosis from 2006 to 2008 in Maringá, State of Paraná, Brazil. METHODS: Three hundred and thirty-five stray dogs and 25 patients were studied. Serum from both animals and patients was examined by the microscopic serum agglutination test to study anti-leptospiral antibodies. To determine the risk areas and the spatial distribution of the disease, thematic maps were designed. RESULTS: Forty-one (12.2%) dogs positive for one or more leptospire serovars were observed, the most frequent serovars being Pyrogenes (43.9%), Canícola (21.9%), and Copennhageni (19.5%). Among the humans, 2 (8%) were positive for serovars Pyrogenes and Hardjo Prajitno and for Pyrogenes and Cynopteri. CONCLUSIONS: Spatial analysis showed that the risk for dogs and humans in the City of Maringá to become infected with leptospires exists in both the central and the peripheral areas, a fact that reinforces the relevance of this study and of continuous epidemiological and environmental surveillance actions to control the disease in animals and in humans.

This research explores the relationship between COVID-19 and social vulnerability on an intra-urban scale. For this, two composite indicators of social vulnerability have been constructed. The composite indicator constructed by the Benefit-of-the-Doubt considers spatial heterogeneity. It weakly captures the conceptually most significant individual indicator of social vulnerability ( R =-0.39), as it overestimates the above-average performance sub-indicators. The composite indicator constructed by the Principal Component Analysis considers that the sub-indicators have the same weights in different census tracts, resulting in a highly consistent composite indicator as a multidimensional phenomenon concept ( R =-0.93). These findings allow reaching four conclusions. First, the direction and strength of correlations associated with COVID-19 are sensitive to the method employed to construct the composite indicator and not just the geographic scale and space. Second, Medium and High social vulnerability census tracts concentrate 97% of the population but only 93% of COVID-19 cases and deaths. Third, people living in census tracts of None and Low social vulnerability are 3.87 and 2.13 times more likely to be infected or die from COVID-19. Fourth, policies to combat COVID-19 in the study area should prioritize older populations regardless of their social conditions.

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Viral hepatitis is a major public health problem in Brazil and worldwide. We retrospectively analyzed 338 cases of hepatitis A, B and C in Maringá, Paraná State from 2007 through 2010. The hepatitis A virus was present in 5.6% of the cases, hepatitis B in 44.7% and hepatitis C in 49.7%. Most of the patients affected were male (55.3%), white (79.6%) and had some primary education (42.9%). Of the 338 cases analyzed, 13.0% had comorbidities. The cases were concentrated in large-population census zones, but it was concluded that the spatial distribution of viral hepatitis in Maringá occurred randomly rather than show any regular pattern.