Demographic, epidemiologic and clinical profile of snake bite cases, presented to Emergency Medicine department, Ahmedabad, Gujarat.

AIM: Snake bite is a common medical emergency faced mainly by the rural populations in tropical and subtropical countries with heavy rainfall and humid climate. Although India is a single largest contributor of snake bite cases, reporting is very poor. There is hardly any publication of the same from Gujarat state that is developing at a good pace. Hence, we aimed to study the snake bite cases with particular attention to demography, epidemiology, and clinical profile. SETTINGS AND
DESIGN: The present descriptive, observational study was carried out at the Emergency Medicine Department of a tertiary care center in Ahmedabad, Gujarat. This department is one if the firsts to get recognized by the Medical Council of India.
MATERIALS AND METHODS: This is a cross-sectional single-center study. Cases were entered into the prescribed form, and detailed information regarding demographic, epidemiologic, and clinical parameters was entered. STATISTICAL
METHOD: Data were analyzed using Epi2000. Means and frequencies for each variable were calculated.
RESULTS: Majority (67.4%) of the snake bite victims were in the age group between 15 and 45 years. Majority were male victims (74.2%). 71% victims of snake bite lived in rural areas. Farmers and laborers were the main victims. 61.2% incidents took place at night time or early morning (before 6 a.m.). 64% patients had bite mark on the lower limb. 40% victims had seen the snake. Eight patients had snake bite, but were asymptomatic. 52% had neuroparalytic manifestation, 34% were asymptomatic, and 9.6% had hemorrhagic manifestation. 14% cases received treatment within 1 h of the bite and 64.84% within 1-6 h after the bite. First aid given was in the form of application of tourniquet (16.2%), local application of lime, chillies, herbal medicine, etc., (1%). 2.20% cases were sensitive to anti-snake venom. Only three patients died.
CONCLUSION: In this region (Gujarat), neuroparalytic manifestation of snake bite is more prevalent. Cobra and krait are the commonest types of poisonous snakes. The time of seeking treatment has reduced because of awareness about snake bite treatment and better transport and ambulance facility. Mortality is very less in well-equipped hospitals due to early initiation of treatment with anti-snake venom.

INTRODUCTION

Snake bite is a common life-threatening condition in many tropical countries; farmers, hunters, and rice pickers are at particular risk and prompt medical treatment is vital.[1] In India, the most important species are cobras (Naja naja, N. oxiana, N. kaouthia), common krait (Bungarus caeruleus), Russell's viper (Daboia russelii), and E. carintus.[2]

India is the largest single contributor to the global tally of snake bite deaths, with the numbers ranging between 15,000 and 50,000 a year. Accurate statistics are not available and there is no standardized reporting of bites and identification of snakes.[3]

Many victims are treated by various kinds of traditional healers. Small surveys have suggested an annual death rate of 1/10,000 in the early 20th century and 3.1/100,000 in the 1950s.[4]

MATERIALS AND METHODS

The present descriptive, cross-sectional, observational study was carried out in Emergency Medicine Department, VS General Hospital, Smt. NHL Municipal Medical College, Ahmedabad, Gujarat. This is one of the first EM departments in India to be recognized by the Medical Council of India. This hospital receives patients from almost all regions of Gujarat.

Ethical committee approval was taken. After obtaining their consent, data were collected on pre-designed, pre-tested, and structured questionnaire by interviewing the study subjects who were hospitalized during the study period.

However, children were not included in the study as there is separate entry point for pediatrics department in this hospital.

Detailed information was collected regarding demographic and epidemiologic parameters such as age, sex, residence, occupation, site of bite and place of bite, type of snake, time interval between snake bite and receiving medical treatment (particularly ante-snake venom). Thorough clinical examination was carried out to identify the type of snake bite (vasculotoxic, neuroparalytic, and nonpoisonous).

Statistical analysis

Statistical tests were applied to calculate the frequencies and means of different variables studied. Epi2000 software was used for this analysis.

RESULTS

A total of 156 cases of snake bite were admitted in the hospital during the study period. Among them, 116 (74.2%) were males and 40 (25.8%) were females.

Majority (71%) of the victims were in the age group of 15-35 years [Figure 1]. Means of age group was 32 ± 5.4 years.

Figure 1

Age-wise distribution of snake bite victims

Majority of the cases (71%) were from rural area and only 29% were from urban area. Among the rural patients, 70.23% cases were bitten in the farms, followed by 24.86% in the houses.

Regarding the occupation of the study subjects, 53.40% cases were farm laborers, 17.80% were farmers, and 28.80% were having other occupations like government servants, housewives, students, etc.

The site of bite was on lower extremity for 62.27% cases, followed by 34.36% on upper extremity, 2.06% on head, neck, and face, and only 0.78% on the trunk [Table 1].

Table 1

Bite site in the affected victims

In the majority (54%) of cases, the timing of snake bite was night or early morning; however, in 32.3% cases, the snake bite took place at daytime [Figure 2].

Figure 2

Timing of snake bite

In 64.5% patients, either the victim or the bystander had seen the snake. As per their description and the photos or snakes that they had brought, the main types of snakes were either krait or viper. In 70% patients, bite mark was seen. Among these, 72% had two clear, distinct bite marks.

Regarding the clinical types, 51% were neuroparalytic snake bites, while 35.5% were asymptomatic. To our surprise, 1.2% had both neuroparalytic and hemorrhagic manifestations [Figure 3].

Figure 3

Clinical presentation of the snake bite victims

Majority (65.4%) had developed symptoms within 1 h of the snake bite; however, few (3.8%) developed symptoms as late as 12 h.

Majority of the cases (84.84%) reached the health care unit within 1-6 h, among which 16.07% reached within 1 h of the bite [Figure 4], 42.3% got treatment between 1 and 3 h, and 30.6% in 4-6 h time span. Among the late presentations, 6.20% visited the health care unit within 6-12 h, 4.13% within 12-24 h, and 7.49% visited more than 24 h after the bite.

Figure 4

Time gap in receiving definite treatment

First aid given was in the form of application of tourniquet (16.2%), local application of lime, chillies, herbal medicine, etc., (6.5%). 2.20% cases were sensitive to anti-snake venom (ASV). Only three patients died, of whom two presented very late with neuroparalytic manifestations. Two victims had dual presentation.

DISCUSSION

In the present study, the incidence of snake bite was found to be 86% in the age group of 15-45 years, which is the active age group involved in various outdoor activities, and so, is more prone for snake bites. Similar findings were observed in other studies.[12]

Male (74.2%) victims were more in number than female victims. The reason for this is males are more involved in outdoor activities compared to females. Male predominance in cases of snake bites was also observed in other studies.[34]

71% victims of snake bite were from rural areas. Farmers and laborers were the main victims. This is because still the farmers and migrant laborers are not using good protective shoes, etc., for their safety. Also, still in India, the contractors are not providing good-quality shoes, etc., for workers’ safety. 64% patients had bite mark on the lower limb.

Apart from farm bites, other incidents took place in the house, reflecting people still having the habit of sleeping out of the house and poor housing (Kachcha Makan) conditions.

55.8% incidents took place at night time or early morning (before 6 a.m.). This reflects the people in rural areas still sleeping at night out of the house and not taking care of their protection. Similar residential differences in snake bite cases were also observed by other authors.[345]

40% victims had seen the snake. Regarding clinical presentation, 52% were having neuroparalytic manifestations, 34% were asymptomatic, and 9.6% were having hemorrhagic manifestations. This reflects that many victims get panicked and are brought in ED even though they do not have poisonous manifestation. This also reflects increased awareness about the snake bite mortality among the general population.

14% cases received treatment within 1 h of the bite and 64.84% within 1-6 h after the bite. Few workers have observed that 85.0% patients were admitted to the hospital within 24 h after the snake bite, and of these, 7.4% were admitted within 1 h.[5] Others,[6] however, have reported that 78.0% cases were admitted within 24 h after the bite and only 6.6% cases were admitted within the first hour. This reflects the fact that persons in rural areas are also aware about the snake bite and early treatment. Good transport and ambulance services may also be the factors.

37.72% cases reached the hospital without any first aid treatment. Among those who received first aid treatment, maximum followed application of tourniquet proximal to the site of bite (16.2%) and local application of lime, chilies, herbal medicine, etc., (6.5%). No incidences of sucking or local incisions were there. Same form of first aid treatment was observed by other authors.[456]

In this study, nonpoisonous snake bite cases formed 31.78%. Highest nonpoisonous snake bite cases were observed by Bhardwaj and Sokhey[7] in 1998 (90.5%), followed by Bakshi[1] in 1999 (61.59%), Bawaskar and Bawaskar[8] in 2002 (49.5%), and Saini[9] et al. in 1984 (41.5%). Kulkarni and Anees (1994)[6] and Hansdak[10] et al. (1998) reported 24.3% and 19.0% nonpoisonous snake bite cases, respectively. In other studies, nonpoisonous snake bites were reported to be between 19.0% and 90.5%.[1678910] This variation in nonpoisonous snake bite cases may be due to variation in the geographic distribution of poisonous and nonpoisonous snakes in various parts of the country.[1112]

In the present study, only 6.20% cases were sensitive to ASV. Those who were sensitive to ASV were treated with steroids, anti-histamine, and other supportive measures. In different studies, the range of hypersensitivity to ASV was from as low as 1.3% to as high as 52.0%.[610]

No allergic reaction to repeated ASV injections was reported by Nigam et al. (1974).[13] The probable reason for this may be administration of corticosteroids to 14 patients of cobra and viper bite out of 22 poisonous snake bite cases by the author.

Only three patients died. The overall mortality rate in the present study was 1.68%. This is much lower than that reported in other studies.[6910] This may be because of increased awareness among the general population, better and early transport, early administration of ASV, better ventilator care, etc., However, the mortality rate after snake bite depends upon various factors like type of snake bite, amount of venom injected, site of bite (serious if bitten on the trunk or head, neck, and face), species and size of the snakes, the extent of its anger or fear, the presence of bacteria in the mouth of the snake or on the skin of the victim. It also depends on exertion, i.e., running immediately after the bite, age, size, and health of the patient.

CONCLUSION

In this region (Gujarat, India), neuroparalytic manifestation of snake bite is more prevalent and cobra and krait are the commonest types of poisonous snake bites. The time of seeking treatment has reduced because of awareness about snake bite treatment and better transport facility. Mortality is very less in well-equipped hospitals due to early initiation of treatment with ASV. Hypersensitivity to ASV can be better managed by intravenous steroid and anti-histaminic medications.