Cases and distribution of visceral leishmaniasis in western São Paulo: A neglected disease in this region of Brazil

Diagnosis of visceral leishmaniasis in Ceará state, Brazil: A flow analysis of cases between 2007 and 2021

OBJECTIVES

To analyse the flow of cases of visceral leishmaniasis (VL) in the state of Ceará, Brazil, between 2007 and 2021.

METHODS

An ecological study was conducted using a spatial approach of newly confirmed cases of VL recorded in the Notifiable Diseases Information System. We identified individuals whose municipality of diagnosis differed from that of their residence. Flow maps, constructed using Tabwin 32 and ArcMap 9.2, allowed for the identification of the volume of traffic between the municipality of residence and that of initial care.

RESULTS

There were 6775 confirmed VL cases. As a flow indicator, 178 counties had at least one resident diagnosed in another municipality in Ceará, with 2491 VL cases and an average trip of 79 km. The largest hub for receiving cases for diagnosis was the capital Fortaleza (1478 patients from 129 other municipalities), followed by Sobral, located in the northwestern region of Ceará (599 from 55 municipalities), and Barbalha, in the southern region (171 from 29 municipalities). In this southern region, 25 municipalities moved 55 people for treatment to Juazeiro do Norte and 11 municipalities moved 39 patients to Crato. A total of 255 patients with VL from 11 municipalities in other Brazilian states, mainly from the Northeast and North, were observed and notified in health services in Ceará.

CONCLUSIONS

The major centres of VL diagnosis outside residence were in the cities of Fortaleza, Sobral, Barbalha, Juazeiro do Norte and Crato. There was also an outflow of cases from other municipalities located in the northeastern and northern regions of Brazil. The flows were more intense during the first triennium of the analysis and milder from 2019 to 2021. Understanding the diagnostic flow of VL helps in decision making and the development of public policies to improve the lives of the population.

Clinical evolution of equine leishmaniasis with self-limiting cutaneous disease caused by Leishmania infantum in northeastern Brazil: A case report

Leishmania infantum infections have long been described in humans and dogs worldwide, but characterization of equine cases remains scarce. We describe the clinical evolution of a natural L. infantum infection to contribute to the diagnostic knowledge and epidemiology of equine leishmaniasis (EL). An auction-acquired four-year-old Mangalarga Marchador mare from Pernambuco state, presented a few subcutaneous nodules on the head and neck upon arrival at the purchaser's stud at Bahia state, in November of 2019. They progressed to multiple ulcerated and non-ulcerated nodules and spread to both right limbs in seven weeks. Hematology revealed anemia, lymphocytosis, monocytosis, and elevated plasma fibrinogen. Histopathology of the biopsied nodules identified a granulomatous dermatitis with macrophages containing Leishmania amastigotes. PCR detected Leishmania in skin lesions, but not in blood or spleen aspirate samples; ITS1 PCR-RFLP and DNA sequencing confirmed L. infantum species. A topical antiseptic and insect-repellent therapy and a monthly follow-up were established. All lesions improved progressively, without specific anti-Leishmania treatment, and 14 months later there was a consistent resolution. This first description of EL by L. infantum in an endemic area is relevant to emphasize the need for epidemiological studies, and to enhance clinicians' awareness for differential diagnosis.

Spatio-temporal relative risks and priority areas for visceral leishmaniasis control in Brazil, between 2001 and 2020

Visceral leishmaniasis (VL) is a pressing public health problem in Brazil. The proper implementation of disease control programs in priority areas is a challenge for healthcare managers. The present study aimed to analyze the spatio-temporal distribution and identify high risk areas of VL occurrence in the Brazilian territory. We analyzed data regarding new cases with confirmed diagnosis of VL in Brazilian municipalities, from 2001 to 2020, extracted from the Brazilian Information System for Notifiable Diseases. The Local Index of Spatial Autocorrelation (LISA) was used to identify contiguous areas with high incidence rates in different periods of the temporal series. Clusters of high spatio-temporal risk were identified using the scan statistics. The accumulated incidence rate in the analyzed period was 33.53 cases per 100,000 inhabitants. The number of municipalities that reported cases showed an upward trend from 2001 onward, although there was a decrease in 2019 and 2020. According to LISA, the number of municipalities considered a priority increased in Brazil and in most states. Priority municipalities were predominantly concentrated in the states of Tocantins, Maranhão, Piauí, and Mato Grosso do Sul, in addition to more specific areas of Pará, Ceará, Piauí, Alagoas, Pernambuco, Bahia, São Paulo, Minas Gerais, and Roraima. The spatio-temporal clusters of high-risk areas varied throughout the time series and were relatively higher in the North and Northeast regions. Recent high-risk areas were found in Roraima and municipalities in northeastern states. VL expanded territorially in Brazil in the 21st century. However, there is still a considerable spatial concentration of cases. The areas identified in the present study should be prioritized for disease control actions.

Vaccination with Formulation of Nanoparticles Loaded with Leishmania amazonensis Antigens Confers Protection against Experimental Visceral Leishmaniasis in Hamster

Visceral leishmaniasis (VL) is a fatal disease caused by the protozoa Leishmania infantum for which dogs are the main reservoirs. A vaccine against canine visceral leishmaniasis (CVL) could be an important tool in the control of human and CVL by reducing the infection pressure of L. infantum. Despite the CVL vaccine available on the market, the Brazilian Ministry of Health did not implement the use of it in their control programs. In this sense, there is an urgent need to develop more efficient vaccines. In this study, the association between two polymeric nanoformulations, (poly (D, L-lactic) acid (PLA) polymer) loading Leishmania amazonensis antigens, was evaluated as a potential immunobiological agent against VL using golden hamsters as an experimental model. The results indicated that no significant adverse reactions were observed in animals vaccinated with LAPSmP. LAPSmP presented similar levels of total anti-Leishmania IgG as compared to LAPSmG. The LAPSmP and LAPSmG groups showed an intense reduction in liver and spleen parasitic load by qPCR. The LAPSmP and LAPSmG vaccines showed exceptional results, indicating that they may be promising candidates as a VL vaccine.

Double Trouble: Dengue Followed by COVID-19 Infection Acquired in Two Different Regions: A Doctor's Case Report and Spatial Distribution of Cases in Presidente Prudente, São Paulo, Brazil

Co-epidemics of COVID-19 and dengue in dengue-endemic countries represent a serious public health concern. In Brazil, São Paulo state ranks first for cases and deaths from COVID-19, and dengue is endemic in most regions of the country. In 2020, an outbreak of dengue occurred in western São Paulo. We determined the spatiotemporal distribution of dengue in the context of COVID-19 cases in Presidente Prudente, a mid-sized city in western São Paulo. To illustrate the burden of both infections, a case report of a doctor and his family, infected with dengue and COVID-19, is presented. There were three clusters of dengue and COVID-19 in the periphery. A dengue cluster was found in a region where there were no corresponding COVID-19 cases. Meanwhile, there were COVID-19 clusters where dengue activity was lower. In 2020, the COVID-19 epidemic emerged when dengue reached its seasonal peak, resulting in a simultaneous outbreak of both diseases. Lower rates of dengue were found in the city compared with 2019, and the fear of patients with mild dengue symptoms about remaining in hospital and acquiring COVID-19 infection may be the main cause. Simultaneous spatial clusters of dengue and COVID-19 in environmentally and socioeconomically vulnerable areas can guide public health authorities in intensive interventions to improve clinical diagnosis, epidemiological surveillance, and management of both diseases. The patient and his family were first infected with dengue and he then carried COVID-19 to his family, reinforcing the risk of health care workers spreading the virus to the community. We highlight the epidemiological significance of presenting a case report and spatial analysis of COVID-19 in the same study in the context of a dengue outbreak.