When the available antivenom does not match the regional venom, clinical innovation becomes essential – Dr Surajit Giri
Snakebite remains an important public-health problem in Assam and Northeast India. One of the major challenges in this region is that the medically important snakes are different from the traditional “Big Four” for which Indian polyvalent antivenom is primarily produced.
The Indian polyvalent antivenom is directed against the venoms of Naja naja, Bungarus caeruleus, Daboia russelii and Echis carinatus.
However, these four species do not represent the major snakebite burden across most of Assam and the Northeast. Russell’s viper has been reported from parts of Assam, including areas such as Bongaigaon, Chirang and Tezpur, but many other parts of the region have a different venomous-snake profile.
The Northeast has a different snakebite problem.
Among the important venomous snakes encountered in Assam and the Northeast are:
* Naja kaouthia – monocled cobra
* Bungarus niger and Bungarus lividus – black kraits.
* Bungarus fasciatus – banded krait.
* Trimeresurus spp. – green pit vipers
* Rhabdophis spp. – keelbacks with medically important venom effects in some cases
In Upper Assam and several neighbouring northeastern states, pit-viper bites constitute an important clinical problem.
Districts and regions where pit vipers are frequently encountered include parts of Golaghat, Jorhat, Sivasagar, Dibrugarh, Tinsukia, Dhemaji, Lakhimpur, Karbi Anglong, Diphu, Dima Hasao and the Barak Valley, with similar clinical challenges reported from neighbouring north-eastern states.
The antivenom gap
At present, India does not have a routinely available, region-specific antivenom covering the important Trimeresurus pit-viper species encountered in the Northeast.
Historically, Indian polyvalent antivenom was sometimes administered to patients with pit viper envenoming. However, based on our clinical experience, the expected therapeutic response was not consistently observed, while some patients developed significant adverse reactions.
Therefore, since 2018, our team at Demow Rural Community Health Centre has adopted a different approach for clinically diagnosed pit viper envenoming rather than routinely administering the available Indian polyvalent antivenom.
This approach was developed through continuing clinical observation and venom-related scientific work, including collaboration with Tezpur University and Prof. Robin Doley.
More than 400 patients were treated without antivenom.
We have now managed 411 clinically diagnosed pit viper bite patients using this approach, without administering polyvalent antivenom.
Our management has focused on:
(i) intensive clinical observation, (ii) repeated monitoring of coagulation status, (iii) monitoring for progression of local swelling, (iv) early recognition of systemic complications, (v) pain management, (vi) magnesium sulphate and glycerine-based local dressing in appropriate cases, (vii) prolonged hospital observation until coagulation parameters recover, (viii) rapid intervention whenever systemic complications develop.
Pit-viper envenoming can produce severe local pain, progressive swelling and prolonged coagulopathy. The swelling may extend across several joints, while abnormalities of blood coagulation can persist for several days.
Patients may therefore remain at risk of serious bleeding and other systemic complications even when they initially appear clinically stable.
The key is not simply “no antivenom” — it is intensive monitoring.
Our message is not that pit viper patients require no treatment. It’s quite the opposite. The treatment is intensive observation and appropriate supportive management. A patient with significant pit viper envenoming should not simply be discharged because there is no locally appropriate antivenom.
In our experience, patients have required hospitalisation for approximately 5–7 days, sometimes longer, until clinical and coagulation parameters become reassuring.
The principle is: the absence of appropriate antivenom does not eliminate treatment options. It means careful diagnosis, prolonged observation, supportive treatment and readiness to manage complications.
Among the 411 pit-viper patients managed under this approach, we have not recorded a death. This represents our institutional clinical experience and should be interpreted in the context of patient selection, clinical protocols, monitoring capacity and the limitations of observational data.
The experience nevertheless raises an important public-health question: Do we need region-specific snakebite protocols for Northeast India?
The answer is clearly that the Northeast requires snakebite-management strategies that reflect its local snake species and local venom profiles.
A one-size-fits-all approach based exclusively on the traditional Indian “Big Four” does not adequately describe the snakebite epidemiology of the Northeast.
Our experience demonstrates the importance of:
Local epidemiology ? local venom research ? appropriate clinical protocols ? trained healthcare workers ? intensive monitoring ? better outcomes.
From Demow to a wider public-health model
The experience accumulated at Demow has contributed to the development of Assam-specific approaches to snakebite management.
Our clinical observations and related work have also been communicated through peer-reviewed scientific publications, while the Assam health system has incorporated region-specific recommendations into its snakebite-management framework.
The larger objective is not to promote one hospital or one individual protocol. It is to ensure that a patient bitten by a pit viper in a remote village of Northeast India receives scientifically informed, locally appropriate and timely treatment rather than an inappropriate reflex treatment or unnecessary referral.
If a person is bitten by a suspected pit viper: (i) do not panic, (ii) do not apply a tourniquet, (iii) do not cut or suck the wound, (iv) do not depend on traditional remedies, (v) reach a health facility as early as possible, and (vi) do not leave the hospital prematurely. The absence of a specific antivenom does not mean that nothing can be done. With appropriate monitoring and supportive management, serious complications can be detected early and treated.
Northeast India needs: (i) region-specific snakebite surveillance, (ii) venom-characterisation studies of local snake species, (iii) development of region-specific antivenoms, (iv) standardised pit-viper management protocols, (v) reliable coagulation testing at peripheral hospitals, (vi) Training of doctors and nurses in snakebite management, and (vii) research collaboration between medical institutions, universities and public-health authorities.
The experience of more than 400 pit-viper patients at Demow provides an important clinical dataset for further scientific evaluation. The snake may be regional, the venom may be regional, and therefore, the solution also needs to be regional.