SARS-CoV-2 among inmates aged over 60 during a COVID-19 outbreak in a penitentiary complex in Brazil: Positive health outcomes despite high prevalence.

OBJECTIVES: To assess SARS-CoV-2 prevalence and health outcomes among inmates over 60 years during a COVID-19 outbreak in a major penitentiary complex in the Federal District, Brazil. METHODS: A mass test campaign was performed on May 13, 2020, using antibody-detection rapid tests for asymptomatic inmates and reverse transcriptase-polymerase chain reaction testing for those who were symptomatic. Those with negative results were retested on June 16. Inmates were interviewed to characterise background health conditions and the presence of symptoms. RESULTS: A total of 159 inmates were evaluated. In the first mass testing, 79.9% (127/159) of inmates had been infected, of whom 53.5% (68/127) reported symptoms. In the second testing round, 17 new cases were identified, increasing the total to 90.6% (144/159) of inmates with a positive result. Comorbidities were present in 67.3% of inmates; 2 hospitalisations and no COVID-related deaths were recorded. CONCLUSION: More than 90% of inmates aged >60 years were infected with SARS-CoV-2 during the outbreak. Periodic health monitoring, active case finding and early care for symptomatic patients contributed to positive post-infection outcomes. Such measures must be considered essential for the surveillance of COVID-19 in environments with limited capacity to promote social distance, such as penitentiary institutions.

COVID-19 Outbreak in a Large Penitentiary Complex, April-June 2020, Brazil.

An outbreak of coronavirus disease began in a large penitentiary complex in Brazil on April 1, 2020. By June 12, there were 1,057 confirmed cases among inmates and staff. Nine patients were hospitalized, and 3 died. Mean serial interval was ≈2.5 days; reproduction number range was 1.0-2.3.

Changes in the dynamics of dengue incidence in South and Central America are possibly due to cross-population immunity after Zika virus epidemics.

OBJECTIVE: We tested the hypothesis that Zika virus (ZIKV) immunity may protect against dengue virus (DENV) infection, disease severity or human amplification, based on analysis of epidemiological data from our long-term surveillance study (2009-2016) in the city of Salvador, Brazil, that indicated a substantial reduction in the frequency of laboratory-confirmed dengue cases following the Zika outbreak. To assess whether similar patterns were observed across the Americas, we did a broader explorative investigation of historical series (2004 to 2019) of suspected cases of dengue fever, covering 20 DENV-endemic South and Central American countries. METHODS: We used segmented linear regressions of single group interrupted time series (ITS) analysis to evaluate whether the Zika epidemic had a statistical effect on the trends of annual dengue incidence. RESULTS: We observed in our 16-year historical series that in all countries, the incidence of dengue exhibited periodic oscillations over time, with a general trend of statistically significant increase during the pre-Zika period overall and for 11 of the 20 countries. Following the peak of the first population exposure to ZIKV in the Americas, in 2016, the overall rate of reported dengue cases in 2017 and 2018 in the countries under study sharply dropped (P < 0.05) and was the lowest reported since 2005. Individually in each country, a statistically significant reduction in the annual dengue incidence beginning in 2016 or in 2017-2018 occurred in 13 of the 20 studied countries. However, in 2019, reports of suspected dengue cases increased across the Americas. In Brazil, Dominican Republic, Guatemala and Honduras, dengue incidence was >5 times higher in 2019 than in 2017 and 2018, and, in 2019, they had the greater dengue incidence than in all previous years throughout the historical series. CONCLUSIONS: The widespread decline in suspected dengue cases recorded in 2017 and 2018 lends further support to our previous epidemiological hypothesis of ZIKV-induced cross-species immunity to DENV. However, the cross-protection appears to be transient (around 2 years). Long-term, prospective follow-ups of dengue reports are needed to confirm (or refute) these findings, which could have significant public health implications, in particular regarding DENV vaccine development and application.

CONTEXTE: Nous avons émis l'hypothèse que l'immunité contre le virus Zika (ZIKV) pourrait protéger contre l'infection par le virus de la dengue (DENV), la sévérité de la maladie ou l'amplification humaine, sur la base de l'analyse des données épidémiologiques de notre étude de surveillance à long terme (2009-2016) dans la ville de Salvador, au Brésil, qui a indiqué une réduction substantielle de la fréquence des cas de dengue confirmés en laboratoire à la suite de l'épidémie de Zika. MÉTHODES: Pour évaluer si des tendances similaires ont été observées dans les Amériques, nous avons mené une enquête exploratoire plus large sur des séries historiques (2004 à 2019) de cas suspects de dengue, couvrant 20 pays d'Amérique du Sud et d'Amérique centrale endémiques pour DENV. Nous avons utilisé des régressions linéaires segmentées de l'analyse des séries chronologiques interrompues pour un seul groupe pour évaluer si l'épidémie de Zika avait un effet statistique sur les tendances de l'incidence annuelle de la dengue. RÉSULTATS: Nous avons observé dans notre série historique de 16 ans que dans tous les pays, l'incidence de la dengue présentait des oscillations périodiques au fil du temps, avec une tendance générale à une augmentation statistiquement significative pendant la période pré-Zika en général et pour 11 des 20 pays. Après le pic de la première exposition de la population au ZIKV dans les Amériques en 2016, le taux global des cas de dengue rapportés en 2017 et 2018 dans les pays étudiés a fortement diminué (p <0,05) et était le plus bas depuis 2005. Individuellement dans chaque pays, une réduction statistiquement significative de l'incidence annuelle de la dengue à partir de 2016 ou en 2017-2018 s'est produite dans 13 des 20 pays étudiés. Cependant, en 2019, les reports de cas suspects de dengue ont augmenté dans les Amériques. Dans des pays comme le Brésil, la République Dominicaine, le Guatemala et le Honduras, l'incidence de la dengue était >5 fois plus élevée en 2019 qu'en 2017 et 2018, et, en 2019, l'incidence de la dengue était plus élevée qu'au cours de toutes les années précédentes de la série historique. CONCLUSIONS: Le déclin généralisé des cas suspects de dengue enregistrés en 2017 et 2018 vient étayer notre hypothèse épidémiologique précédente de l'immunité inter-espèces induite par le ZIKV contre le DENV. Cependant, la protection croisée semble être transitoire (environ 2 ans). Des suivis prospectifs à long terme des reports sur la dengue sont nécessaires pour confirmer (ou réfuter) ces résultats, qui pourraient avoir des implications importantes pour la santé publique, en particulier en ce qui concerne le développement et l'application d'un vaccin DENV.

Avaliação da infectividade parasitária a Lutzomyia longipalpis por xenodiagnóstico em cães tratados para leishmaniose visceral naturalmente adquirida / Evaluation of parasite infectivity for Lutzomyia longipalpis by xenodiagnosis in dogs treated for natural visceral leishmaniasis

O efeito de um protocolo quimioterápico multidrogas contra a leishmaniose visceral (LV) canina, sobre a capacidade de transmissão de Leishmania infantum ao vetor, foi analisado por meio de xenodiagnóstico. Trinta e cinco cães naturalmente infectados foram avaliados antes e durante o tratamento com a combinação de metronidazol, cetoconazol e alopurinol a cada três meses por até um ano. Em cada avaliação, os cães foram individualmente submetidos ao xenodiagnóstico e quantificação da carga parasitária por PCR quantitativa. O tratamento foi eficaz em bloquear a transmissibilidade parasitária do cão para o flebotomíneo (p= 0,011) nos cães avaliados. Houve significante correlação entre recuperação clínica e infectividade: cães com melhora clínica mais evidente apresentaram menores chances de transferir L. infantum ao Lutzomyia longipalpis via xenodiagnóstico (r=0,528, p= 0,002). Esses resultados demonstram que o tratamento canino com o protocolo proposto pode representar uma alternativa ao sacrifício de cães no Brasil como medida de controle da doença, uma vez que as drogas utilizadas não são aplicadas ao tratamento da LV humana em áreas endêmicas.(AU)

The outcome of a multidrug chemotherapeutic protocol against canine visceral leishmaniasis (VL) has been evaluated for its effect on dogs' capacity of transferring Leishmania infantum to sand flies by xenodiagnosis. Thirty-five naturally infected dogs were examined before and during treatment with a combination of metronidazole, ketoconazole, and allopurinol, at every three months up to one year. For each evaluation, treated dogs were individually submitted to xenodiagnosis and quantitative PCR to quantify parasite load in sand flies. The treatment was effective in blocking parasite transmission from host to sand flies (p=0.011) in the assessed dogs. There was a significant correlation between clinical improvement and sand fly infectivity: dogs that achieved better clinical conditions showed a lower chance of L. infantum transference to vector by xenodiagnosis (r=0.528, p=0.002). These results demonstrate that the treatment of dogs with the proposed protocol may represent an alternative to dog culling in Brazil for disease control, since these drugs are not used for treating human VL in endemic areas.(AU)

Temporal distribution of positive results of tests for detecting Leishmania infection in stray dogs of an endemic area of visceral leishmaniasis in the Brazilian tropics: a 13 years survey and association with human disease.

Human visceral leishmaniasis occurs in periodic waves in endemic areas of Brazil. In this study we followed the prevalence of human visceral leishmaniasis and of Leishmania infantum infection in stray dogs of an endemic area of visceral leishmaniasis at periods of time between 1997 and 2010. Prevalence of human visceral leishmaniasis had two peaks (40 cases) in 1997 and 2006 with sharp declines to 2 cases in 2001 and to 5 cases in 2008. Similar fluctuations were also observed in the occurrence of positive spleen culture and anti-Leishmania serology in dogs, although the proportion of dogs with active spleen parasitism remained relatively high even in the periods of low prevalence of human disease. These observations support the notion that stray dogs may constitute a renewable source of parasites, capable of sustaining the persistence of the infection in urban areas, even in periods of low transmission by phlebotomines.