Sero-survey of IMA- Branch Saharanpur -September-2020

 Sero-survey of IMA- Branch Saharanpur -September-2020

Project Coordinator –Dr Ravikant Nirankari (M.D.)

Email-ravi_nir@yahoo.co.in 

Project Advisor - Dr Rajnish Dahuja (M.D.) 

Dr.Subhash Sehgal (M.S.)

Dr.Kaleem Ahmad (M.D.)

 

COVID-19 Pandemic is spreading very rapidly all over the world. Now we are getting many asymptomatic patients also. To restrict the spread of infection vaccine and herd immunity is the hope for all. Herd immunity can be achieved when a certain percentage of population in defined area become infected or get vaccinated for that disease. Many institutes have conducted the sero survey in different parts of worlds to know to sero-conversion rate in population. CDC, ICMR have already conducted this kind of survey. 

Sero survey of Indian medical association branch Saharanpur was conducted in first half of September 2020. Sample were collected between 1st of September 2020 to 18th of September 2020.Purpose of this sero-survey was to detect the sero-conversion in health care workers of Saharanpur district. This was purely voluntarily act and all the participants participated by their own. ICMR permitted and adviced for sero survey for patients who were immune compromised and ailing from other disease. Individual in containment zone ,Essential service providers like police and Health care workers, migrants, prisoners and people living in compact slums should be involed in sero survey to know the spread of infection and sero conversion in these groups of people.

This Survey was a semi sponsored event of IMA as a 50 percent subsidy was given to all participants from social welfare funds of IMA for payments to Lab. Survey was conducted with the help of  private sector lab(Pathkind Lab) and all the blood sample were sent to Gurugram based center from where reports were collected by email.

The quantitatative test for IgG level we used in this survey is  Diasorin SARS Cov-2 S1/S2 IgG test to detect specific antibody to SARS COV-2 by indirect chemiluminiscence immunoassay. The specific recombinant S1 and S2 antigen were used along with mouse monoclonal antibody to human igG linked to isoimmune derivatives. Antibody typically appears after 2 week of infection. This test have a sensitivity of 97.4 percent and specificity of 98.9 percent.

Criteria of inclusion in sero-survey-Following groups of participants were included in this study with prior consent and and all the participants were asymptomatic at the time of blood sample collection.

1-Doctors (private as well as govt sector)

2-Non medico family members of doctors

3-Hopsital / clinic staffs 

We analyzed all the results in 5 major categories

1-Doctors

2-Non medical family members

3-Hospital/clinic staff

4-Total number of HCW

5-Negative Vs equivocal results

                       

                           TABLE:1-POSITIVE RESULTS AMONG DOCTORS

NUMBER OF DOCTORS NEGATIVE POSITIVE PERCENTAGE OF POSITIVE

180

161

19

10.5 %

       TABLE:2- POSITIVE RESULTS AMONG DOCTOR’S FAMILY MEMBERS

NON MEDICO FAMILY MEMBERS

NEGATIVE POSITIVE PERCENTAGE OF POSITIVE

              62

50  

12

19.3 %

  

             TABLE:3- POSITIVE RESULTS AMONG  CLINICAL STAFF

TOTAL NUMBER OF CLINICAL STAFF  

NEGATIVE

POSITIVE

PERCENTAGE OF POSITIVE

89

86

3

3.3 %

                                   

TABLE-4 TOTAL POSITIVE RESLUTS IN ALL PARTICIPANTS (HCW)

Total number of participants(HCW) Negative Positive Percentage of positive

331

297

34

10.27 %

TABLE:5- TOTAL  NEGATIVE Vs EQUIVOCAL REULTS

TOTAL NUMBER OF PARTICIPANTS TOTAL  NEGATIVE

(INCLUDING EQUIVOCAL RESULTS) EQUIVOCAL

RESULTS PERCENTAGE OF EQUIVOCAL/NEGATIVE RESULTS PERCENTAGE OF EQUIVOCAL/TOTAL RESULTS

331

297

78

26.2%

23.5%

Discussion of Results:-

FROM TABLE:1- Total 180 doctors participated in sero survey and out of them 19 came positive for IgG. This is 10.5 percent of total. Large number of participants had a report of equivocal value that can become positive after a period of time. If we add that value in the positive results and repeat all equivocal sample after 15 days then this percentage may go more than double of current value.

FROM TABLE:2- In this group total 62 family members of different doctors  gave their blood sample and out of them 19 family members were positive for IgG . Most of them are those famiies where doctor is also positive for IgG. This is very important to say here that family members of doctors are at great risk of exposure because of working doctors.

FROM TABLE:3-   In this group we analysed the blood reports of hospital/clinic staff of doctors who are working there and doing works as ward boy, OPD attendants,pharmacist, nursing staff and sweepers etc. Total 89 participants from different hospitals were involeved in surey and out of them only 3 participants came positive for IgG .That is only 3.3 percent of total clinical staff members.

FROM TABLE:4- Total number of participants from Saharanpur health care workers (HCW)  group and their family members who participated in sero survey were 331 out of them total 34 participants came positive for IgG test. This is 10.27 percent of total participants.

INTERPRETATIONS OF RESULTS:- According to CDC most of the sero survey conducted so far gave a positive result between 5% to 10% only. Result of  this sero survey of IMA Saharanpur city also came near to that value.

In India ICMR has conducted sero surevy in many metro cities of india and there has been a high value of positive results. When we see the results of total participants its only 10.27 percents which is very far from the level we need for herd immunity. This low level of positive results may be due to small sample size and many reports were in equivocal value that can become positive if we repeat the test after certain period of time.

Overall this result reflects that there is very high chance of asymptomatic  sero conversion in health care workers because of their contact with COVID-19 patients .When we compare different groups of people we see a different result ,around 20 percent family members are IgG positive for COVID-19 who participated in this survey. Here all doctors need to be careful and aware not to transmit this infection to their families.  

  Now come to the hospital and clinic staff members, very surprisingly we got only 3.3 percent participants positive for IgG test that is even very less than the percentage of positive doctors which is 10.5 percent. First reason may be small sample size if we include more participants this percentage can go high .Second reason can be a result of good IPC training given to all clinic and hospital staff to prevent the infection and this is good indication for all the doctors that their staff is very well trained and all are following the IPC rules to prevent the spread of infections.

Conclusion:-  This kind of survey in asymptomatic population reflects the level of seroconversion  in general and specific population groups  Although positive IgG test for COVID-19 is not a certainty for becoming immune to reinfection and still need more research work in this field as many case of reinfection have been reported in many parts of the world but number of that cases is very very low as compared to actual number of patients in the world. There can be multiple factor behind the reinfection like age , comorbidities and many more factors can play a role that need more research works.

                                                                                      

                                 (SPECIAL NOTE- Thank you all the participants and IMA Sre to give me this opportunity for this study.)

                                                                                                                           Dr.Ravikant Nirankari (M.D.)- Author of the article