Snakebite: Epidemiology, Prevention, Clinical Presentation and Management
2000; King Faisal Specialist Hospital and Research Centre; Volume: 20; Issue: 1 Linguagem: Inglês
10.5144/0256-4947.2000.66
ISSN0975-4466
Autores Tópico(s)Rabies epidemiology and control
ResumoBrief ReportsSnakebite: Epidemiology, Prevention, Clinical Presentation and Management Hisham M. MahabaMD Hisham M. Mahaba Address reprint requests and correspondence to Dr. Mahaba: Department of Community Medicine, Faculty of Medicine, Ain Shams University, Cairo, Egypt. From the Research Department, Directorate of Health Affairs, Hail, Saudi Arabia Search for more papers by this author Published Online:1 Jan 2000https://doi.org/10.5144/0256-4947.2000.66SectionsPDF ToolsAdd to favoritesDownload citationTrack citations ShareShare onFacebookTwitterLinked InRedditEmail AboutIntroductionExposure to a variety of venomous animals, including snakes and scorpions, represents an environmental health risk in Saudi Arabia. High incidence rates have been reported in Hail region during the last few years.1,2 Apart from a few case reports,3–8 there are no published data on the epidemiology of snakebite or the clinical effects of envenomation in Saudi Arabia. Fifty-one species of snakes have been identified in the Arabian Peninsula9 and nine are known to be poisonous in inland Saudi Arabia, including species such as Naja Haje arabicus, Walterinnesia aegyptia, Bitis arietans, Echis carinatus, Echis coloratus, Cerastes cerastes gasparetti and Atractaspis microlepidota.10,11 The aim of this report was to study the epidemiology, clinical presentation and management of snakebite in the Hail region and to evaluate the role of health education in their prevention.PATIENTS AND METHODSSurveillance of all cases of snakebite was carried out between June 1996 and June 1998. Specially designed reports on snakebite were completed by doctors at all hospitals and primary health care centers (PHCCs), and sent to the Research Department, Directorate of Health Affairs, at Hail region for analysis. The reporting of cases of snakebite was not a voluntary process and was continuously checked as a part of the supervision of different activities at these centers by their supervisors. Data obtained included personal details, clinical presentation, details of the snakebite, identification of the type of snake in terms of color, length, shape of bite, etc., and management of the bite.12Health education programs for the prevention of snakebites were planned by the Research Department and implemented by all PHCCs and hospitals in the region. The message included methods of avoiding snakebites (e.g., avoiding walking barefooted, especially at night, avoiding sleeping outdoors, keeping the environment free of waste products, and the use of light when walking in the desert at night), as well as the use of first-aid measures. The messengers included PHC staff, doctors, nurses, health inspectors and hospital staff managing cases of snakebite. The media included direct face-to-face education through lectures, patient education by medical staff and indirect methods, using specially designed posters and leaflets distributed to all health facilities in the Hail region. The target population included all patients attending PHCCs and hospitals in the region, especially cases of snakebite. The program was conducted between June 1997 and June 1998. Demographic data were obtained from the Statistical Annual Report of PHC Administration in Hail Region, Saudi Arabia.13,14 Analysis of the data was carried out using the computer program SPSS for Windows.RESULTSA total of 70 cases of snakebite were reported during the study period. Fifty-two cases were reported during the first year of the study, between June 1996 and June 1997. They included two cases in which the victims were found dead in the desert, with snakebites being diagnosed as the cause of death by a forensic medicine consultant.Table 1 describes the incidence of snakebite in the Hail region before and during the health education program. The incidence rate declined significantly, from 18 to 6 per hundred thousand population, after the implementation of the program (χ2=18.31, P<0.0001). The decline was statistically significant in all groups except for children (0-15 years). Non-Saudis had a significantly higher incidence of snakebite than Saudis, and males had higher incidence rates than females (χ2=18.32, P<0.003). The incidence of snakebite increased with age, and the decline in incidence rates after the health education program was marked among adults. Rural population (outside Hail city) had significantly higher incidence rates than the urban population (inside the main city). This was true for both before (χ2=24.0, P<0.000) and after the program (χ2=14.25, P<0.0001).Table 1. Incidence rates (per 100,000 population) of snakebites in Hail region during the studied period.Table 1. Incidence rates (per 100,000 population) of snakebites in Hail region during the studied period.The peak incidence of snakebite occurred during the summer months (Table 2), and was especially high during June and July. The lower limb was the most common site of bite (66 cases, 94.3%), and they occurred mostly at night (43 cases, 63.2%). Walking barefooted or wearing slippers, and incompletely covering the feet at night were the most common predisposing factors for snakebite (66 cases, 94.3%). Most cases (60, 85%) suffered outdoor bites. The offending snake was killed and available in 16 cases (22.8%), and these snakes included Cerastes cerastes gasparetti (7), Echis coloratus (4), Malpolon moilensis (4), and Walterinnesia aegyptia (1). In the remaining 54 cases, the type of snake was not identified (Table 2).Table 2. Conditions related to snakebites in Hail regions.Table 2. Conditions related to snakebites in Hail regions.The manifestations of snakebite included local pain in 68 cases (97.1%), restlessness in 15 cases (21.4%), hypertension in 7 cases (10%), pallor in 7 cases (10%), and fever in 2 cases (2.9%). Local examination of the wounds revealed swelling in 30 cases (42.8%), hematoma in 15 cases (21.4%) and gangrene in only one case (1.4%).The interval between the accident and seeking medical advice was less than one hour in 42 cases (60.0%). A total of 56 cases (80%) were hospitalized. Antivenin was the main line of treatment. It was given in 67 cases (95.8%). Skin testing prior to injection of antivenin was positive in four cases (5.8%). Other drugs used included steroids, analgesics and antitetanic serum.The case fatality rate was 2.9% of cases per two years (Table 3). Unfortunately, investigations were available for only some of the hospitalized patients. As shown in Table 4, leukocytosis and slight prolongation in prothrombin time and mild elevation in blood urea nitrogen were the most common abnormalities found.Table 3. Clinical presentation, antivenin treatment and prognosis of snakebites in Hail region.Table 3. Clinical presentation, antivenin treatment and prognosis of snakebites in Hail region.Table 4. Hematological investigations for cases of snakebite in Hail region.Table 4. Hematological investigations for cases of snakebite in Hail region.DISCUSSIONThe sociocultural behavior and geographical features of Saudi Arabia expose its inhabitants to the risk of contact with a variety of venomous animals. Although modern means of transportation have contributed to the decrease of such contact, the risk is still present. Only a few studies have described the incidence rates of venomous bites in Saudi Arabia, and the size of the problem is still not fully appreciated.12Recent studies have shown a high incidence of scorpion bites in the Hail region.1,2 This incidence (about 1% per year) was much higher than the incidence of snakebite found in this study. However, the case fatality rate was much higher for snakebites than for scorpion stings (2.9% vs. 0.04%).The higher incidence of snakebite among non-Saudis may be due to the occupational exposure of migrant foreign workers such as shepherds and farmers, and the higher rates in males can be explained by their increased outdoor exposure. The peak incidence of snakebite in the summer months is explained by the hybernation of snakes during winter.14 The risk of snakebite increased with age, possibly due to the greater outdoor exposure of adults.Incidence rates for snakebite declined after the health education program, indicating the possibility of avoiding snakebite simply by wearing shoes and not walking barefooted. The decline in incidence rates was significant in all groups studied except for those below 15 years of age. This may be due to the fact that this age group was not involved in the health education program, since they receive care through the school health services.Snakebites affected mainly the lower limbs (94.3%). This supports the feasibility of preventing bites by not walking about barefooted. Most of the bites occurred during the night (63.2%), reflecting the nocturnal activity of snakes.The venom of poisonous snakes may be predominantly neurotoxic (coral snake) or cytolitic (pit viper). Neurotoxins cause respiratory paralysis. Cytolitic venom causes tissue destruction by digestion and hemorrhage due to hemolysis and destruction of the endothelial lining of the blood vessels. The manifestations of cytolitic envenomation, e.g., rattlesnake venom, are local pain, redness, swelling and extravasation of blood. Perioral tingling, metallic taste, nausea and vomiting, hypotension and coagulopathy may also occur. Neurotoxic envenomation may cause ptosis, dysphagia, diplopia and respiratory arrest.15The most commonly identified snakes were Cerastes cerastes gasparetti (7, or 10%) and Echis coloratus (4, or 5.7%). In addition to examination of wounds, clinical manifestations (swelling, hematoma, bleeding) and investigations (prolonged prothrombin time, thrombocytopenia and reduced hemoglobin), we suggest that these two snakes are the most important toxic (cytolitic) snakes identified in this study. Walterinnesia aegyptia, which is mainly neurotoxic,14 was encountered in only one case. Other bites are caused mainly by the less toxic snake Malpolon moilensis and other non-toxic snakes.The interval between the accident and seeking medical advice was less than one hour in 42 cases (60%), indicating the need for more health education and stressing the importance of seeking earlier medical advice.Antivenin was the main line of treatment in cases of snakebite. The high percentage of positive skin tests stresses the importance of this test prior to the intravenous injection of the antivenin.Health education in PHCCs was shown to be useful in the prevention of snakebite. Education of schoolchildren is to be included in future health education programs for prevention of venomous bites and stings.ARTICLE REFERENCES:1. Mahaba HM, El Sayed. "Scorpion sting: is it a health problem in Saudi Arabia? Evaluation of management of 820 cases" . Saudi Med J. 1996; 17:315–21. Google Scholar2. 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Saudi Med J. 1993; 14:196–202. Google Scholar9. Gasperetti J. "Snakes in Arabia" . J Saudi Nat Hist Soc. 1977; 19:3–16. Google Scholar10. Gasperetti J. "Snakes of Arabia" . Fauna of Saudi Arabia. 1988; 1:9. Google Scholar11. Al-Sadoon MK. "Survey of the reptilian fauna of the Kingdom of Saudi Arabia" . J King Saud Univ Sc. 1989; 1:53–69. Google Scholar12. Mohamed KS, Soud AE. Poisonous snakes in the Kingdom of Saudi Arabia: types, breeding sites and prevention against their toxins. 2nd edition. Saudi Arabia: King Saud University, Faculty of Science, 1992:22. Google Scholar13. Statistical Annual Reports. Directorate of Health Affairs, PHC administration, 1416:15–16. Google Scholar14. Statistical Annual Reports. Directorate of Health Affairs, PHC administration, 1417:30–1. Google Scholar15. Olson KR. Poisoning: snake bites. In: Lawrence MT, Stephen J, Papadakis MA, editors. Current medical diagnosis and treatment. 35th edition. USA: Appleton & Lange, 1996:1413–4. Google Scholar Previous article Next article FiguresReferencesRelatedDetails Volume 20, Issue 1January 2000 Metrics History Received11 May 1999Accepted25 September 1999Published online1 January 2000 InformationCopyright © 2000, Annals of Saudi MedicinePDF download
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