1.Why does a person not acquire immunity against Rabies natural infection,as it occurs in other viral infections?

     There is no viremia in rabies,which means that the rabies virus is not present in blood till the last stages and therefire a failure to provoke a humoral response.From the site of bite the virus enters a nerve and via axoplasm reaches  the central  nervous system(CNS).

     Only after travelling efferently from CS via mostly autonomic nerves to different organs,the antibody production starts.But by that time,the patients brain stem neuronal cells are destroyed and he dies in a day or two,either due to respiratory paralysisor due to cardiac arrest.

2.can rabies be transmitted from man to man?

     Theoretically ,Saliva of a hydrophobic patient is infectious and occasionally such transmission is reported.But the well-documented transmission is through corneal transplantation.Hence ,Confirmation of cause of death ,particularly in neurological cases is very importent before corneal transplantation.Besides it is also importent to avoid contact with saliva and other secretions of a rabies patient.

3.    Are there any survivors of Rabies hydrophobia?

      There are 3 recorded survivors of rabies, 2 from USA (1970 &1977) and 1 from Argentina (1972).All had received some mmunoprophylaxis and they recovered following intensive care.No specific drug / therapy is resposible for their recovery(Kalpan,et.al.).

         In India , 2 survivors are reported from AIIMS,Delhi (1988)but they are not well acclaimed due to the lack of laboratory evidence in Diagnosis.

4.Does kissing of a hydrophobia call for PET immunization?

     The saliva of a hydrophobia patient contains the rabies virus andis infective.If there is suspicion about contact with saliva of hydrophobia patient during kissing,the partner requires 5 doses of TCV or class.

      II scheduled of NTV if there are ulcers in the mouth of the contact person then even serum  or HRIG would be waranted.

5.Can rabies be transmitted through sexual intercourse?

      Rabies virus is present in the semen and to some extent in vaginal secretions.In some patients,priapism ,incresed sexual libido and indulgence is seen(both in men and women patients).Hence ,in the contact(exposed)person,5 doses of TCV as PET (or class II of NTV schedule)should be given. If there is double of class IIIexposure viz.abrasion on penis or in vagina then even serum or HRIG must also be given.

6.A pregnant woman develops hydropobia.What sould be done?

         In humans ,rabies virus is not known to cross the placental barrier and consequently the foetus is safe.Hence ,Hydrophobia pregnant woman should be clinically managed and if induction of labour/caesarian section is possible,the obstetrician shall di it with due"personal precautions" and immunoprophyaxis (3 doses of TCV usually or if any accidental negligible exposure / doubt 5 doses of any TCV).

         The new born has to bre given 5 doses of any TCV as PET or if the hydrophobic mother(who will invariably die) is poor then class I pET schedule of NTV should  be given.

7.What is the average incubation period?

        The average incubation period(i.e time from exposure to appearance of the first clinical signs)is considerd to be 20 to 90 days.

        The period of incubatio ,however may be much sorter (a few days) or,conversely,much longer,several months (or even more than a year).

8.What  are the contraindications for PET?

     Rabies is 100% fatal and hence there is no contraindication to PET.

9.Can a rabies vaccine be given to a pregnant woman?

     All rabies vaccines inculding Nerve Tissue vaccines are known to be safe duriong pregnancy.Besides pregnant woman with h/o animal bite are susceptible to rabies and should be given PET.Hence,following ARV administration ,MTP should not be done as a routine clinical practice.

10.Can a pregnant woman be given preexposure vaccination?Modern TCVs are considered generally safe during pregnancy (as of reports available till now)and n treatogencity or other adverse effects are reported during pregnancy.However ,Pregnanat woman whereever possible,should avoid animal bites and pre-exposure vaccination.If this is not possible,then they may be given pre-exposure immunization.

11.Can a lactating mother be given anti-rabies vaccine?

     All anti-rabies vaccines are inactivated vaccines and can safely be given to lactating mothers as it has no effect on the breast fed baby.

12.What is the crieteria for "Protection" after immunization?

      Rabies Neutralizing Antibody titre of >0.5 IU/ml . of serum is considered protective.Facilities of analysing antibody titres are available at select centres like CRI,Kasauli,Himachal Pradesh;Pasteur Institute,Cooner,Tamilnadu;NICD,Delhi,NIV,Pune;NIMHAS ,Bangalore & few other centres.