Rabies threat again alarms Kerala - Mathrubhumi English

Unexpected deaths of three children due to rabies within two weeks have rocked Kerala. When Alappuzha native Nirmal Rajesh (14) and a tribal girl Archa (17) died without getting timely treatment and vaccination, seven-year-old Anand succumbed to the infection even after being inoculated by three shots of rabies vaccine. The bites of the rabid dog in high risk areas, including face, scalp and upper lip were reported as the cause of death in Anand's case. 

With the surging menace of stray dogs and the reports of deaths due to rabies, people have to be more vigilant about the infection and the vaccination procedures. 

Dr Sruthi Haridas, consultant physician at PVS Hospital in Kozhikode, elaborated on the rising concerns of rabies infection and vaccination proceedings to Mathrubhumi.com

In which circumstances does rabies affect a person and become fatal even after receiving vaccines ?

There are occasional human rabies cases reported despite vaccination after exposure, due to various factors related to negligence and individual health status. Most cases have been reported due to delayed vaccination, or non-use of rabies immunoglobulin in category III (severe) exposure, or incomplete course of vaccination. Some cases are related to immunocompromised status such as HIV/AIDS, cirrhosis or use of chloroquine, steroids or anti-cancer drugs. Unexplained failure in cases where everything was apparently done correctly have also been documented.

What are the post exposure recommendations for rabies? 

Touching, feeding or licking on intact skin of the suspected rabid animal will result in no exposure of rabies and these types of contacts are enlisted as 'Category I' according to the guidelines of World Health Organisation.  

Category II includes nibbling of uncovered skin, minor scratches or abrasions without bleeding. For such exposures, immediate vaccination and local treatment of wounds have to be administered. 

Single or multiple transdermal bites or scratches, contamination of mucous membrane or broken skin with saliva from animal licks and exposures due to direct contact with bats are considered as severe exposures in category III which need immediate vaccination and administration of rabies immunoglobulin along with local treatment of wounds. 

Which are the major rabies vaccines used in India?

Modern anti-rabies vaccines currently available in India are the human diploid cell vaccine (HDCV – Rabivax), purified Vero cell rabies vaccine (PVRV – Verorab, Aventis Pasteur, Abhayrab, Indirab), purified chick-embryo cell vaccine (PCECV - Vaxirab N, Rabipur) and purified duck embryo vaccine (PDEV- Vaxirab). PDEV is not in commercial production these days. There is no major difference among the three products ( HDCV, PCECV, PVRV) available commercially. PVRV and PCECV are the most commonly used in India and these vaccines have replaced HDCV since they are less expensive and are as safe and effective.

Rabies vaccine is usually administered via intramuscular (IM) or intradermal (ID) route. Since the cost of PVRV and PCECV is still too high for many developing countries like India, given the amount of post exposure vaccination that is needed, the World Health Organization (WHO) strongly advocates the use of intradermal regimes. 

A systematic review of vaccine potency has shown that current vaccines, when administered by the intradermal route for either pre or post exposure treatment, have efficacy equivalent to or higher than that of the same vaccine administered by intramuscular route. Rabies antigen inoculated into the dermis of the skin helps to trigger a high immune response as the antigen presenting cells in the skin are more effective than the ones in muscle. 

The best treatment of rabies include: the combined administration of rabies immunoglobulin (RIG) if indicated, along with a course of anti-rabies vaccine and local treatment of the wound. The anti-rabies serum/Rabies Immunoglobulin (RIG) provides passive immunity in the form of ready-made anti-rabies antibodies, before it is physiologically possible for the victim to begin producing his/her own antibodies following anti-rabies vaccination. So RIG must be administered to all Category III animal bites (severe exposure - single or multiple transdermal wound etc), all wild animal bites and class II bites ( minor scratches or abrasions without bleeding) in immunocompromised individuals. However, rabies immune globulins are in short supply. In India alone, it is estimated that, only 2 percent of patients whose wounds require the rabies immune globulin receives appropriate post-exposure treatment. Due to global shortages of rabies immunoglobulin and the expense of production, alternate means to prevent disease are being sought.

Monoclonal antibodies (mAbs) capable of neutralizing a diverse range of rabies isolates could offer a solution to address the cost, supply and safety issues. Rabishield is a first-of-its-kind rabies human monoclonal antibody in the world, licensed in India in 2017. It is more potent and therefore requires a lower dose than current rabies immune globulins and it is much more cost effective. Twinrab, which is a combination of two murine mAbs, has been recently licensed. 

Are they cent percent efficient ?

All modern anti-rabies vaccines are highly potent, effective, safer to use and provide immunity for a longer period of time.

How much will the rabies vaccine cost in the state? 

Rabies vaccines are distributed free of charge in the hospitals and clinics run by the government. In private institutions, varied prices ranging from Rs 350 to Rs 400  are charged for a dose according to different manufacturers. For instance, the Rabivax of Serum Institute costs Rs 358 here. 

Please elaborate on the vaccination procedure?

In case of the treatment intended to prevent getting rabies, especially in high risk individuals such as children and animal handlers, one dose vaccination has to be taken each on day 0, day 7, and day 21 or 28 (total 3 visits and 3 doses). Main advantage is that it simplifies post exposure management. There is no need for RIG/mAb following subsequent severe exposure. 

Treatment after being bitten by animal include: 

• Standard Intramuscular anti-rabies vaccine schedule

One dose of vaccine is administered intramuscularly on days 0, 3, 7, 14 and 28 [single site injection/ total 5 visits required]. Injections must be given in the upper arm or, in small children, into the thigh muscle. Vaccines should never be administered into the buttocks, where absorption is low due to the presence of fat tissue. 

• Intradermal anti-rabies vaccine schedule

One dose each is given at two sites, on both arms on day 0, day 3, day 7 and day 28 [ two site injections / total 4 visits required]. Though several vaccination schedules are there, the above are the commonly practiced ones.

• Rabies immunoglobulin 

RIG, if indicated, should be administered immediately or within 24 hours of animal bite along with the first dose of vaccine. If the vaccine alone was started, then it can be given till 7 days after starting the first dose of vaccine. It can be administered even a week or more later if the person has not received any vaccine. As per the latest WHO guidelines, skin testing prior to rabies immunoglobulin is not recommended. As much as possible should be infiltrated around the wound and below it. 

Any rabies vaccine given on the buttock region is considered invalid. With the same dose, the vaccine is safe to be used in infants, in women during pregnancy and lactation.

From a medical perspective, is there any solution to ward off stray dog menace?

The stray dog population in India is increasing day by day. Regrettably, 30%–60% of the dog-bite victims are children under the age of 15 and people of poor socioeconomic status. Children are more often affected as the small stature of the child makes them more vulnerable to be bitten on face and neck. Also, children tend to report less to parents fearing injection. Thus small bites and licks may go unnoticed and untreated leading to fatal disease.

• First and foremost step to be taken to ward off stray dog menace is nothing but 'environmental cleanliness'. Street dogs would not be able to maintain their population density unless food and shelter are provided by man, with or without intent. With development of cities, managing the solid waste has become a great challenge and the centralised facilities more often fail in delivering the expected level of service. Thus, unmanaged leftovers aid the proliferation of stray dogs.
• Control of stray dog population by the animal birth control method has little or no impact on population densities according to the study by R. Chandran (2016), unless it is accompanied with a group of actions such as reducing the carrying capacity of the habitat (by excluding sources of food, shelter, and human acceptance). 

  

  Sterilization surgery | Photo: Mathrubhumi

   
• There is also a need for creating awareness among dog owners regarding periodic vaccination of their pets against rabies and other zoonotic diseases.
• Providing regular vaccination for stray dogs during animal birth control operations for both male and female dogs as a continuous programme involving voluntary organisations, shelter/rehabilitation/treatment to prevent mass appearance of dogs.
• In addition, there should be collaborative planning of medical, veterinary and environmental specialists to sort out this menace.

The effort initiated by the Government of India in rolling out the National Rabies Control Programme is a timely move for effecting rabies control. A multifaceted approach for human rabies eradication for implementing the preventive measures is necessary to achieve the World Health Organisation goal of reducing the number of cases of dog-mediated human rabies to zero by the year 2030.