Clinical and epidemiological aspects of scorpionism in the interior of the state of Bahia, Brazil: retrospective epidemiological study

ABSTRACT BACKGROUND: Scorpion accidents have gained great visibility around the world because of the high frequency and severity with which they occur, and have become a global medical-sanitary problem. OBJECTIVE: The aim of this study was to describe the sociodemographic, clinical and epidemiological profile of scorpionism in the municipality of Jequié, Bahia, Brazil, from 2007 to 2015. DESIGN AND SETTING: Retrospective epidemiological study in the municipality of Jequié, Bahia, Brazil. METHODS: This study was based on data collected from the epidemiological investigation notification forms of the injury information system. RESULTS: There was an increase in the coefficient of incidence of scorpion accidents in Jequié from 23.4/100,000 in 2007 to 413.6/100,000 in 2015. There were 3565 cases: 54.9% were female, 58.8% were aged 20-59 years, 63.5% had brown skin color and 48.6% had incomplete primary education. Most accidents occurred in urban areas (93.1%). Homes were the main place of occurrence (84.5%) and upper limbs were the commonest sting sites (53.0%). Regarding clinical aspects, 66.4% of the cases received hospital assistance within one hour after the bite, 84.1% presented mild severity, 97.1% had local manifestations and 10.2% had systemic symptoms. Serum therapy was administered in 17.3% of the cases, and 99.9% evolved to cure. CONCLUSION: There was an increase in the incidence of scorpion accidents in the municipality, which demonstrates the need for investment in actions that reduce the morbidity and mortality caused by these accidents, such as educational campaigns and improvements in socioeconomic and health conditions.


INTRODUCTION
Accidents caused by venomous animals have undeniable importance within public health.
Among these accidents, those caused by scorpions are gaining great visibility around the world, due to the high frequency and severity with which they occur, and have become a global medical-sanitary problem. 1 Every year, an estimated 1.5 million cases and an estimated 2,600 deaths due to scorpionism occur worldwide. 2 In Brazil, between 2000 and 2012, there was an increase of 323% in the incidence rate and 475% in mortality due to scorpion accidents, with an average of 19.6 accidents and 0.030 deaths per 100,000 inhabitants. 3 In Brazil, wide territorial distribution of occurrences has been observed, with emphasis on the northeastern region, which has the highest rates of incidence and mortality. The state of Bahia accounts for more than 30% of the notifications in this region and has the highest average annual mortality rates in this country. 4,5 Most scorpion species have specific habitat and microhabitat requirements, along with predictable ecological and biogeographic patterns. However, some species have high ecological plasticity and irregular distribution, which favors their occupation of environments that have been disturbed or modified by man. These species find shelter and food near and/or inside human dwellings. 6 In view of this, and since scorpionism is also a social problem, investigation of this phenomenon at the microregional and local levels becomes important, especially through the use of techniques that can identify areas and social groups of greater risk. A further justification for conducting such investigations is the current lack of studies showing the aspects of scorpion accidents in small urban centers, where these events are quite frequent and access to health services is limited.

METHODS
This was a retrospective epidemiological study on scorpion accidents reported in the municipality of Jequié, Bahia, Brazil.
The study population was composed of all of the cases of accidents involving scorpion stings that were reported at the Prado Valadares General Hospital (PVGH) between 2007 and 2015.
This hospital was chosen as the data-gathering site because it is the only serum dispensing unit in Jequié and is therefore the reference point for hospital care in cases of scorpionism in this municipality.
The data were collected directly from the epidemiological investigation sheets of the notifiable health hazard information system The victims ( Table 1) were predominantly female (54.9%), aged between 20 and 59 years (58.8%), of brown skin color (63.5%), with incomplete primary education (48.6%) and living in the urban area (94.8%). In relation to occupation, 29.0% were minors or only students.
Accidents occurred more frequently in the urban area (93.1%), and the victim's home was the main place of occurrence (84.5%).
Regarding the location of the bite, the upper limbs were the body segments most affected, accounting for 53.0% ( Table 2). Tables 2 and 3 The time that elapsed between being bitten and receiving hospital care was mostly less than one hour (66.4%). Most of the cases (84.1%) were classified as mild, while 2.0% presented a severe clinical picture. Serum therapy was administered in 17.3% of the cases, and 99.9% evolved to cure.

DISCUSSION
Over the period analyzed, there was an alarming increase in the coefficient of incidence of scorpion accidents in the municipality of Jequié (23.4/100.000 to 413.6/100.000). This was higher than the increase that has been estimated for all of Brazil: between 2001 and 2012, the accident rate went from 10.5/100,000 to 32.3/100,000. 4 The coefficient for Jequié also differs from what has been found in other municipalities in this country, such as in Campina Grande,  8 where there were declines in the coefficient, from 132.0/100,000 to 108.0/100,000 and from 28.6/100,000 to 24.3/100,000, respectively.
It should be noted that in the present study, the growth shown may reflect not only the increase in the number of cases, but also improvements in the notification process. The coefficient increased in 2009, when the Hospital Epidemiology Center of the PVGH was implemented. Through this, compulsory notifications of diseases and health hazards began to be carried out in a judicious manner. In addition, increased awareness within the population regarding the emergency nature of these accidents may have given rise to greater demand for healthcare services, and thus may have increased the numbers of notifications.
Regarding the monthly distribution, it was observed that the accidents did not present seasonal behavior, and a certain degree   where scorpion accidents have been reported to be more frequent in the hotter and rainier periods of the year.
The process of urbanization has been reported to be a factor contributing towards scorpionism. This was also observed in the present study, since 94.8% of the accidents occurred in urban zones, as seen in other studies conducted in different regions of Brazil 7,12 and in Sudan. 13 The urbanization of scorpionism has been explained as being due to disordered urban growth, the inadequacies of infrastructure and the environmental imbalance. 14 Uncontrolled increases in the urban population lead to occupation of irregular areas, with severe infrastructure problems such as lack of basic sanitation and poor housing conditions. These are factors that favor availability of shelter and proliferation of these animals. 15 In addition, the ease of adaptation of scorpions to changes in the environment, in combination with difficulties in implementing preventive programs within the population, boost the risks of occurrence of such accidents. 16 The higher frequency of accidents suffered by females corroborates other surveys conducted in Brazil l7,12,17 and in other countries. 10,18 The fact that the highest frequency of accidents was at home (85.5%), together with the high proportion of cases  in which the victim's occupation related to domestic activities, provides emphasis in explaining why the proportion of women affected was greater. Females in this setting might have greater exposure related to domestic activities, such as cleaning of places that often serve as shelter for scorpions, such as sinks, bathroom drains, clothing and shoes. 7 Nevertheless, other studies have pointed out higher occurrence of male scorpionism. 9 Activities performed outside the home, especially those relating to construction and agriculture, have been reported to be related to scorpion accidents. 16 The high proportion of the scorpion bite victims of the present study that were classified as having the sociodemographic characteristic of low schooling corroborates the findings of a previous study on venomous animal poisoning in Brazil. 4 That study showed that there were negative correlations between scorpionism and literacy and the Human Development Index (HDI). These findings contribute towards the hypothesis that socially and economically disadvantaged populations present greater vulnerability to scorpion accidents, 3 considering that schooling contributes towards better socioeconomic conditions.
The location of the bite has been reported to be one of the factors that influence the severity of cases, such that the closer it is to vital organs, the greater the complications and possibilities of side effects will be. 19 In the present study, it was found that the upper limbs were the body segments most affected, similar to what was found in other studies. 9,12,18 This result shows that scorpion bites usually occur while household chores are being done, 8,12 or when the victims are putting on their clothes or shoes, 12 or while working in environments that are considered to provide suitable shelters for these animals, without using personal protective equipment (PPE) such as gloves and boots.
Another matter that deserves attention is early treatment for injured people. If it is necessary to apply therapeutic serum, this should be administered as soon as possible, so that the venom is immediately neutralized. In the present study, the largest proportion of the victims were hospitalized less than one hour after the sting, similar to what was observed in studies conducted in northeastern Brazil, 7 the state of Ceará 12 and the city of Belo Horizonte. 8 From the point of view of epidemiological surveillance, this finding may mean that there were improvements to access to information concerning the need for urgent medical services in cases of scorpion stings. 8 The findings from the present study indicate that the healthcare service in this region is providing relatively good medical care for the victims of scorpionism.
Furthermore, the fact that attendance was provided quickly may explain why a greater proportion of the cases were classi-  However, despite such limitations, the SINAN system of the Brazilian Ministry of Health was seen to be an important tool for conducting epidemiological studies, given that it is the official database for registering diseases and health hazards in Brazil.

CONCLUSION
This study showed that the coefficient of incidence of scorpion accidents in the municipality of Jequié has increased. The clinical and epidemiological profile of the scorpionism cases in this study corroborates what has been found in other surveys in Brazil and in other countries, i.e. predominance of scorpionism in urban areas, among the economically active age group with low schooling levels. The importance of early hospital care for better evolution of cases was also observed.
These findings indicate that multidisciplinary actions involving different healthcare sectors, environmental management and the population itself are essential for reducing morbidity and mortality due to scorpionism. Among such actions, the most important of these are investment in educational campaigns, improvements in socioeconomic and health conditions, and improvements in the hospital care provided for bite victims, so as to ensure immediate care.