Epidemiology of Animal Bites and Stings in Khuzestan, Iran, 1997—2006

Journal of Infection and Public Health (2008) 1, 51—55

View metadata, citation and similar papers at core.ac.uk brought to you by CORE

provided by Elsevier - Publisher Connector

Epidemiology of animal bites and stings in Khuzestan, Iran, 1997—2006

Seyed Mohammad Alavi a,b,∗, Leila Alavi c

a Infectious Disease Ward, Razi Hospital, Joundishapour University of Medical Sciences, No. 52, West 11 Avenue, Kianabad, Ahvaz, Iran b Joundishapour Infectious Diseases and Tropical Medicine Research Center, Iran c Shahid Chamran University, Iran

Received 29 July 2008; accepted 18 August 2008

KEYWORDS Summary Dog bites; Objectives: To determine the incidence and characteristics of the injuries caused Scorpion stings; by animals among the population of Khuzestan region, Iran admitted to teaching Animal injuries; hospital emergency departments. Study: Retrospective study. Rabies Place and duration of study: From 1997 to 2006 in teaching hospitals in Ahvaz, Iran. Methodology: The medical records of 894 patients admitted to hospital with animal bites or stings were studied. Data including epidemiological aspects, clinical findings and outcomes of treatment were analyzed using descriptive statistics and the 2 test. Results: Of 894 patients 62.0% were male, and the median age of males and females was 24.4 years and 26.2 years, respectively. Dogs, scorpions, mice and snakes were the most commonly involved animal species, causing injuries with a frequency of 69%, 12.5%, 8.8% and 4.4%, respectively. Feet (58.1%) and hands (30.6%) were the most commonly affected body parts, followed by the face and other parts. Infec- tious complications were seen in 127 patients, among them 94 soft tissue infections (74.1%), 28 cases of sepsis (22.0%) and five of endocarditis (3.9%). Thirty-five cases (3.9%) died following animal bites and stings, among them 28 (80%) due to scorpion stings, four (11.4%) related to dogs and three (8.6%) from snake bites. No cases of rabies were observed in these patients. Conclusion: Animal bite is a major public health problem in Khuzestan, with a high frequency, a high percentage of hospitalization and considerable mortality. © 2008 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

∗ Corresponding author. Tel.: +98 611 3387724; fax: +98 9161184916. E-mail address: [email protected] (S.M. Alavi).

Introduction number of bites, previous vaccination against rabies and tetanus, symptoms, treatment and According to the WHO, 10 million people are bit- preventive measures carried out at the primary ten by animals around the world each year and health center, laboratory investigations, clinical are considered for prophylaxis and treatment for features, complications, disabilities, deaths and rabies, from which almost 50 000 people die annu- timescale of these events. Data were analyzed in ally. The highest rates of mortality and morbidity SPSS 11.5 (SPSS Inc., Chicago, IL, USA) by using in Asia are observed among developing countries descriptive statistics and the 2 test. [1—3]. Animal bites and stings are among the most common injuries, both in Iran and worldwide [4]. In countries that animals, and especially dogs, are Results kept in conditions of poor hygiene, dog bites are the most common animal bites and can result in com- During the period of study, 44 088 cases of animal plicated bacterial infection predominantly related bite were reported to KHC. The majority of the to the dog’s oral flora [5,6]. Bites and scratches bites were mild, and after receiving antivenom represent the most important public health issue (specific for scorpion or snake) and vaccination for related to dogs and cats because of the asso- rabies and tetanus patients were discharged. We ciated physical and psychological trauma, wound found 1872 medical files containing animal bites infection by different microorganisms, and the risk and stings, only 894 of which were usable for this of rabies transmission [5,7—11]. Cellulitis is the study. The rate of hospital admission for animal most common clinical feature, and rarely, sepsis, bites and stings was 4.2%. Of the 894 studied osteomyelitis and rabies may develop after bite patients 62.0% were male, and the median age of injury [5]. Vaccination against rabies before and males and females was 24.4 years and 26.2 years, after animal bite is the most effective measure respectively. The age and gender distributions of to prevent rabies [4,5]. Scorpion stings and snake patients with animal bites and stings are shown in bites are also serious and fatal animal exposures Table 1. Dog, scorpion, mouse and snake bites were in Iran, occuring with similar frequency and having the most common, with frequencies of 69%, 12.6%, similar health consequences [4,12,13]. Annually, 8.8% and 4.4%, respectively. Animal bites/stings 140 cases of animal bite per 100 000 population according to animal species and whether the are estimated to occur in Iran; more than 85% patient’s home was in a rural or urban area are of them are dog bites [4,3]. Khuzestan province shown in Table 2. Feet (58.1%) and hands (30.6%) is ranked ninth in the country in this respect. were the most commonly affected body parts, Due to the high frequency of animal bites/stings followed by face and other parts (Table 3). Scorpion (3000—6000 cases per year), the large number of stings were treated at the emergency department stray dogs, the high prevalence of scorpions and with specific antivenom against Hemiscorpius snakes in some areas of Khuzestan [14] and few epi- lepturus, the most fatal scorpion, after diagnosis demiological data about this major public health by a trained health care worker. Seventy-two problem, this study was performed to determine patients were diagnosed as having been stung by the incidence and characteristics of the injuries H. lepturus. Statistically significant difference caused by animals among the population of Khuzes- tan admitted to teaching hospital emergency departments. Table 1 Age and gender distribution of patients with animal bites and stings Bite/sting Materials and methods n (%) This was a retrospective descriptive study per- Gender Male 554 62.0 formed in Khuzestan province, south west Iran, Female 340 38.0 which has a population of 4 480 000. The medical Age ≤5 45 5.0 records of those who were bitten or stung by (years) 6—15 214 23.9 animals between 1997 and 2006 and admitted 16—25 251 28.1 to Khuzestan Health Center (KHC) or teaching 26—35 221 24.7 hospitals affiliated to Joundishapour University 36—65 135 15.1 of Medical Sciences (JUMS) were reviewed. Data ≥66 28 3.1 were collected on age, gender, residence (rural Total 894 100 or urban), type of animal, site of bite or sting, Epidemiology of animal bites and stings in Iran 53

Table 2 Animal bites and stings according to animal species and patient’s residence Animal Total Rural area Urban area P-value n (%) n (%) n (%) Dog 617 (69.0) 494 (79.4) 123 (45.2) <0.001 Cow 11 (1.2) 9 (1.4) 2 (0.7) 0.30 Donkey 8 (0.9) 8 (1.3) 0 (0) 0.053 Mouse 79 (8.8) 7 (1.1) 72 (26.5) <0.001 Cat 28 (3.1) 14 (2.3) 14 (5.1) 0.021 Scorpion 112 (12.5) 60 (9.6) 52 (19.1) 0.001 Snake 39 (4.4) 30 (4.8) 9 (3.3) 0.20 Total 894 (100) 622 (100) 272 (100)

Table 3 Body part affected according to main animal species Animal Face Hand Foot Other parts Total n (%) n (%) n (%) n (%) Dog 31 (5.0) 185 (30.0) 370 (60.0) 31 (5.0) 617 Cat 5 (17.9) 12 (42.9) 9 (32.1) 2 (7.1) 28 Mouse 15 (19.0) 36 (45.6) 23 (29.1) 5 (6.3) 79 Scorpion 2 (1.8) 28 (25.0) 73 (65.2) 9 (8.0) 112 Snake 0 (0) 11 (28.2) 28 (71.8) 0 (0) 39 Other animal 0 (0) 2 (10.5) 16 (84.2) 1 (5.3) 19 Total 53 (5.9) 274 (30.6) 519 (58.1) 48 (5.4) 894 in the number of animal bites between the rural Discussion and urban populations (Table 2) were observed: (dogs, 79.4% vs. 45.2%, respectively, mice, 1.2% vs. Our study showed that 4.2% of animal bites and 26.5%, respectively and scorpions, 9.6% vs. 19.2%, stings were treated at health centers or hospitals respectively). Cows and snakes had similar bite fre- in the region of study. This finding is consistent quencies in rural and urban populations (Table 2). with previous reports that the majority of animal Dogs, scorpions and snakes frequently affected the bites result in mild injuries that patients do not foot with a rate of 60—70%, whereas cats and mice seek medical help for [6,15—17]. In this study chil- affected the hand with a frequency of 40—45% dren and young adults were affected more than (Table 3). Multiple bites and injuries were observed other age groups and men were affected more than to be caused by cats and dogs with frequency women, with a male to female ratio of 1.63:1. of 20% and 8%, respectively. Hospital medical This finding is in agreement with Nogalski et al. records showed that 127 patients had infectious [6], Weis et al. [11], Hon et al. [12], Matteucci complications such as soft tissue infection [94 et al. [18] and Shetty et al. [19]. O’Neil et al. (74.1%)], sepsis [28 (22.0%)] and endocarditis [5 [17] and Mac Bean et al. [7] explained that female (3.9%)]. All patients with mammal bites were vac- adults were more likely than male adults to be cinated against rabies and treated with anti-rabies attacked by cats. The present study showed that immunoglobulin and there were no cases of rabies dog bites constitute about 70% of all animal bites among these patients. Thirty-five patients (3.9%) that affect people, around 12% are scorpion stings died of animal bites and stings, among them 28 and nearly 9% are mouse bites, while the remain- (80%) due to scorpion sting, four (11.4%) related ing 9% are caused by other animals such as cats to dog bite or injury and three (8.6%) from snake and snakes. MacBean et al., Hon et al., Weiss et bite. Ten patients were left with a disability: al., Nogalski et al., Shetty et al., Dao et al., and two requiring chronic hemodialysis following Ndon et al. reported that dogs (80%), cats (10%) scorpion stings and eight with leg paralysis after and horses (10%) were the most common animals dog injuries. The death rate among patients with injuring humans [6,7,11,12,16,19,20]. These differ- scorpion sting was 25%, mostly due to H. lepturus ences may be due to variation in the behaviors, (94.3%). occupations and belief of people living in different 54 S.M. Alavi, L. Alavi socioeconomic and epidemiological situations. The were all age groups. The first limitations was the present study revealed that most dog bites occurred small number of those with serious injuries requir- in rural areas, whereas those bitten by mice, cats ing hospitalization, suggesting that these results do and scorpions were predominantly in urban areas. not reflect the full extent of the problem. Another Cattle injuries and snake bites were similar in both limitation is that the results of treatment were areas. Nogalski et al. reported that the threat of estimated at the time of discharge, but patients animal attack is similar in urban and rural areas were not followed up, so these results may have [6]. MacBean et al. explained that in Australia, most some inaccuracies. injuries by animals occurred in the home and were caused by pet dogs and cats. These differences may be related to many factors, such as the high Conflict of interest number of stray dogs in rural areas of the region of our study, the high number of mice in sewage There is no conflict of interest. canals and entering homes in urban areas of our region, the high number of pet dogs and cats in industrial countries, and differences in occupation, Acknowledgments behaviors and socioeconomics around the world. In our study, the majority of infectious complications The authors wish to thank the chief and personnel were seen in dog and snake bites. This finding is of Joundishapour Infectious Diseases and Tropical confirmed by the data from the literatures [5].Two Medicine Research Center for supporting this study. main factors are responsible for this observation. We also acknowledge Dr Kamali, the chief of the The first is the bacterial flora of dog and snake zoonosis department of KHC, and health students saliva, which infects human tissue, and the second Mr. Savari and Mr. Haghjoo for their kind assistance factor is the trauma caused by powerful dog’s jaws, in data collection. which results in tissue ischemia in the region of the bite. In addition, the cytotoxic effects of snake toxin predispose the affected tissue to infection References [5,6]. In our study, the mortality rate in hospitalized [1] WHO. The work of WHO in the eastern Mediterranean patients was 3.9%, with scorpion stings accounting region. Annual report of the regional director, Alexandria: of 80% of deaths. Nogalski et al. found that the World Health Organization Regional Office for the Eastern mortality rate in hospitalized patients was 5.88%, Mediterranean; 2003. mostly due to serious injuries caused by large ani- [2] WHO. Strategies for the control and elimination of rabies mals such as horses, cows and pigs. Weiss reported in Asia. Geneva: WHO; 2001. [3] Fayaz A. The diseases with vector or reservoir: rabies. In: a mortality rate among hospitalized animal bite Azizi F,Hatami H, Janghorbani M, editors. Epidemiology and patients of 1.6 per 1000. These differences may control of prevalent diseases in Iran. 2nd ed. Tehran, Iran: be due to: (1) the presence of potentially lethal Nashre eshtiagh; 2004. p. 542—57. scorpion species such as H. lepturus in the area, [4] Tabatabaei SM, Zahraei M, Ahmadnia H, Ghotbi M, Rahimi F. (2) severe and serious injuries to the head, face Principles of disease prevention and surveillance. 2nd ed. Tehran: Roohghalam; 2006. and abdomen caused by horses and cows, (3) the [5] Goldstein JC Bites. In: Mandel GI, Bonnet JE, Dolin R, edi- medical facilities and best management of injured tors. Principles and practice of infectious diseases. 6th ed. patients in the emergency departments of industri- New York: Churchill Livingstone; 2005. p. 2552—7. alized countries. In the present study we observed [6] Nogalski A, Jankiewicz L, Cwk G, Karski J, Matuszewski no case of rabies or tetanus. The threat posed by L. Animal related injuries treated at the Department of Trauma and Emergency Medicine, Medical University of rabies is increasing in Iran due to the high num- Lublin. Ann Agric Environ Med 2007;14:57—61. ber of stray dogs and cases of dog bite in humans [7] MacBean CE, Taylor DM, Ashby K. Animal and human bite [3]. Dao et al. reported 10 cases of human rabies injuries in Victoria 1998—2004. Med J Aust 2007;186:38—40. in their retrospective study [20] covering a four- [8] Healey D. Fatal dog bites in New Zealand. N Z Med J year period (2000—2003). Surprisingly however, no 2007;120:1259—65. [9] Casterodale L. Hospitalizations resulting from dog bite cases of human rabies were observed in our study. injuries. Alaska, 1991—2002. Int J Circumpolar Health This may be because of increasing public aware- 2007;66:320—7. ness and the upgrading of health and treatment [10] Day H, Roesler JS, Kinde M. Hospital treated dog bites in centers, all of which in the region of study pro- Minnesota 1998—2005. Minn Med 2007;90:43—5. vide post-exposure anti-rabies treatment including [11] Weis HB, Friedman DI, Coben JH. Incidence of dog bite injuries treated in emergency departments. JAMA vaccination, immunoglobulin and wound washing. 1998;279:51—3. The strength of our study was that all cities and [12] Hon KL, Fu CC, Chor CM, Tang PS, Leung TF, Man CY, et al. villages in the region of study were included, as Issues associated with dog bite injuries in children and ado- Epidemiology of animal bites and stings in Iran 55

lescents assessed at the emergency department. Pediatr [16] Ndon JA, Jack GV, Wehrenberg WB. Incidence of dog bites Emerg Care 2007;23:445—9. in Milwaukse, Wis. Wis Med J 1996;95:237—41. [13] Pipelzadeh MH, Jalali A, Taraz M, Pourabas R, Zaremi- [17] O’Neil ME, Mack KA, Gilchrist J. Epidemiology of non- rakabadi A. An epidemiological and clinical study on canine bite and sting injuries treated in USA emergency scorpionism by the Iranian scorpion Hemiscorpius lepturus. department, 2001—2004. Public Health Rep 2007;122: Toxicon 2007;50:984—92. 764—75. [14] Khuzestan Health Center. Annual Report on Health Activi- [18] Matteucci MJ, Hannum JE, Niffenbergh RH, Clark RF. Pedi- ties. JUMS 2000:169—73. atric sex group differences in location of snake bite injuries [15] Hashemi SA, Esfandiari B, Fayaz A, Behzadi HN, Kavoosi requiring antivenom therapy. J Med Toxicol 2007;3:103—6 S, Ziapour SP, et al. Investigation on animal and human Erratum in: J Med Toxicol 2007;3:145—8. rabies in cases from Mazaindran and Golestan provinces [19] Shetty RA, Chaturvedi S, Singh Z. Proﬁle of animal bite cases referred to the Amol Research Center, Northern Iran in in Pune. J Commun Dis 2005;37:66—72. 2003—2005, The Internet Journal of Microbiology 2007;4. [20] Dao S, Abdillahi AM, Bougoudog F, Toure K, Simbe C. http://www.ispub.com/ostia/index.php?xmlFilePath= Epidemiological aspects of human and animal rabies in journals/ijmb/vol4n1/rabies.xml [accessed 16 September the urban area of Bamaka Mali. Bull Soc Pathol Exot 2008]. 2006;99:183—6.

Available online at www.sciencedirect.com