Febre maculosa no município de Pedreira, SP, Brasil. Inquérito sorológico

Urbanization of Brazilian spotted fever in a municipality of the southeastern region: epidemiology and spatial distribution

INTRODUCTION

Brazilian spotted fever is an emerging zoonosis notified mainly in the Southeast of Brazil, especially due to its high level of lethality.

OBJECTIVE

To analyze the epidemiological and spatial pattern of the disease in the municipality of Valinhos (106,793 inhabitants), São Paulo, Southeastern region of Brazil, in the period between 2001 and 2012.

METHODS

All laboratory-confirmed cases with likely site of infection in the city (n = 49) notified in the Brazilian Case Registry Database were studied. Sites were geocoded using the cartographic base of the city and Google Earth (geographic coordinates) with correction according to the Brazilian Geodetic System. We used the Kernel estimator to analyze the density of the cases on the map. Land cover and distance to basins of all cases were analyzed. Information about tick species and primary hosts were obtained from reports of the Superintendence of Control of Endemic Diseases.

RESULTS

Seasonality of the disease was observed with the highest incidence from June to November, and in 2005 and 2011. The most affected groups were men (79.6%) aged 20-49 years old (49%). Lethality was found to be 42.9%. Maps showed the progressive registration of cases in the urban area. Capybaras were reported as the main primary host, and Amblyomma cajennense was identified in probable sites of infection during field investigation. The likely sites of infection were mostly located near basins, dirty pastures, and bordering woods.

CONCLUSIONS

The transmission pattern of Brazilian spotted fever in Valinhos is similar to that in other cities in the region, where capybara is the main primary host and an amplifier of R. rickettsii. Over the years, a higher occurrence of cases has been identified in the urban area of the city.

Brazilian Spotted Fever with an Approach in Veterinary Medicine and One Health Perspective

There is increasing interaction between man and pathogens transmitted by arthropods, especially by ticks. It is on this background that a holistic approach stands out, for the sake of Public Health. Brazilian Spotted Fever is an endemic disease at the country's southeast, with Amblyomma sculptum as its major contributor, followed by A. aureolatum and potentially Rhipicephalus sanguineus. Dogs have been considered sentinels, and in some areas the disease in dogs can precede human disease. Considering the importance of this disease for human health, the serological evidence in dogs, and the transmission of ticks between dogs and their owners, this review aimed to elucidate the importance of the epidemiological investigation, the diagnosis in dogs, and the role of veterinarians in Public Health to control vector-borne zoonotic diseases. We encourage veterinarians to include this rickettsial infection in the diagnosis of febrile diseases of common occurrence in dogs.

Antibodies to Rickettsia rickettsii, Rickettsia typhi, Coxiella burnetii, Bartonella henselae, Bartonella quintana, and Ehrlichia chaffeensis among healthy population in Minas Gerais, Brazil

Rickettsial diseases except those belonging to spotted fever group rickettsioses are poorly studied in South America particularly in Brazil where few epidemiological reports have been published. We describe a serosurvey for Rickettsia rickettsii, R. typhi, Coxiella burnetii, Bartonella henselae, B. quintana, and Ehrlichia chaffeensis in 437 healthy people from a Brazilian rural community. The serum samples were tested by indirected micro-immunoflourescence technique and a cutoff titer of 1:64 was used. The seroprevalence rates for R. rickettsii, R. typhi, C. burnetii, B. henselae, B. quintana, and E. chaffeensis were respectively 1.6% (7 samples); 1.1% (5 samples); 3.9% (17 samples); 13.7% (60 samples); 12.8% (56 samples), and 10.5% (46 samples). Frequent multiple/cross-reactivity was observed in this study. Age over 40 years old, urban profession, and rural residence were significantly associated with some but not all infections rate. Low seropositivity rates for R. rickettsii, R. typhi, and C. burnetii contrasted with higher rates of seropositivity for B. quintana, B. henselae, and E. chaffeensis. These results show that all tested rickettsial species or antigenically closely related possible exist in this particular region.

[Spotted fever in Campinas region, State of São Paulo, Brazil]

Brazilian spotted fever was detected for the first time in the State of S o Paulo in 1929. However, there is no systematic reporting of the disease in the State. In 1985, three cases of the disease occurred in the municipality of Pedreira, located in the Campinas Region, belonging to the 5th Administrative Region, in the Northeast part of the State, including 88 municipalities. An investigation was conducted at the time, but the lack of case registry limited its scope. The present study was undertaken with the aim of recovering the history of the disease in the Region. Data recovered from several public health services for 1985-2000 were used to analyze incidence patterns. It was observed that the transmission area expanded and the number of suspected cases increased, especially after 1996, when mandatory reporting was established. Deaths due to spotted fever were observed in most of the years under study. The study concluded that spotted fever incidence is increasing in the Campinas Region. Complementary bio-ecological studies are currently under way to better understand the epidemiology of this disease, recognized worldwide as an emerging public health problem.

[Isolation of Rickettsia in vero cell culture]

The diagnosis of spotted fever is based on characteristic signs and symptoms but requires laboratorial confirmation because of the possible differential diagnosis from other diseases like leptospirosis, enterovirus, meningococcemia and typhoid fever. Laboratorial confirmation may be done by detection of specific antibodies which is possible only 5-10 days after the onset of the symptoms or by the isolation of Rickettsiae from blood and/or skin biopsy and from ticks collected in the patient or in the animal reservoir. The isolation of Rickettsiae from blood or skin biopsy results in an early diagnosis of spotted fever since in the rickettsiemic phase of the disease there is no detectable level of antibodies in the serum. With the purpose of facilitating the diagnosis of Spotted Fever we have standardized the isolation of Rickettsiae in cell culture by a method that is less time consuming and that reduces the biological risks than isolation in guinea pigs. Vero cell cultures were inoculated with the Sheyla Smith strain of Rickettsia rickettsii provided by CDC (Atlanta-USA). The identification was performed by indirect immunofluorescence technique. The presence of green fluorescent organisms characterized the growth of the agent. Ulterior confirmation of the methodology was done by isolation of the spotted fever agent from skin biopsy of a patient from an endemic area and from Amblyomma ticks that are the reservoir and vector of the Brazilian spotted fever.