Vimal Raj, R., K. Vinod Kumar, AP Sugunan, K ...

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Leptospira interrogans. 9. Icterohaemorrhagiae Lai Like. AF 61. Leptospira interrogans. 10. Louisiana. Louisiana. LSU 1945. Leptospira noguchii. 11.
Vimal Raj, R., K. Vinod Kumar, A.P. Sugunan, K. Natarajaseenivasan and P. Vijayachari, 2017. Homologous microscopic agglutinating antibodies after natural infection with leptospires - results from a long term follow up of a cohort living in an endemic area. Pathogens and global health, 111(5): 265-269. Supplementary document Table S1. Panel of leptospiral serovars used in MAT S.No

Serogroup

Serovar

Strain

Genomospecies

Reference strains 1

Australis

Australis

Ballico

Leptospira interrogans

2

Autumnalis

Bangkinang

Bangkinang I

Leptospira interrogans

3

Canicola

Canicola

HondUterecht IV

Leptospira interrogans

4

Djasiman

Djasiman

Djasiman

Leptospira interrogans

5

Grippotyphosa

Grippotyphosa

Moskva V

Leptospira interrogans

6

Grippotyphosa

Grippotyphosa

CH 31

Leptospira interrogans

7

Hebdomadis

Hebdomadis

Hebdomadis

Leptospira interrogans

8

Icterohaemorrhagiae

Icterohaemorrhagiae

RGA

Leptospira interrogans

9

Icterohaemorrhagiae

Lai Like

AF 61

Leptospira interrogans

10

Louisiana

Louisiana

LSU 1945

Leptospira noguchii

11

Pyrogenes

Robinsoni

Robinson

Leptospira interrogans

12

Pomona

Pomona

Pomona

Leptospira interrogans

13

Sejroe

Hardjo

Hardjoprajitno

Leptospira interrogans

14

Javanica

Poi

Poi

Leptospira borgpetersenii

15

Bataviae

Bataviae

Swart

Leptospira interrogans

16

Cynopteri

Cynopteri

3522C

Leptospira kirschneri

17

Tarassovi

Rama

316

Leptospira santarosai

18

Mini

Mini

Sari

Leptospira borgpetersenii

19

Sarmin

Sarmin

Sarmin

Leptospira weilii

Strains recovered from patients 1

Grippotyphosa

Ratnapura

FIS01a

Leptospira interrogans

2

Grippotyphosa

Ratnapura

FIS03a

Leptospira kirschneri

Ratnapura

FIS04

a

Leptospira kirschneri

FIS05

a

Leptospira interrogans

a

Leptospira kirschneri

3 4

Grippotyphosa Grippotyphosa

Valbuzzi

5

Grippotyphosa

Ratnapura

FIS09

6

Grippotyphosa

Ratnapura

FIS10a

Leptospira kirschneri

Ratnapura

FIS11

a

Leptospira kirschneri

a

Leptospira interrogans

7

Grippotyphosa

8

Hebdomadis

Hebdomadis

FIS12

9

Hebdomadis

Hebdomadis

MG 54

Leptospira interrogans

10

Hebdomadis

Hebdomadis

MG 66

Leptospira interrogans

11

Icterohaemorrhagiae

Copenhageni

FIS02a

Leptospira interrogans

12

Pomona

Pomona

MG 39

Leptospira interrogans

13

Pomona

Pomona

MG 90

Leptospira interrogans

a

Leptospira interrogans

15

Sejroe

Saxkoebing

FIS02

Microscopic Agglutination test The cases of leptospirosis detected in this study either by blood culture or by MAT were infected with 10 serovars of Leptospira belonging to seven serogroups. The concurrent circulation of Leptospira strains of such diverse serogroups and serovars in a relatively small community living in limited geographical area shows how essential is it for a vaccine to have the ability to elicit cross-protection against multiple serovars. Among the cohort of 14 culture positive cases, the maximum heterologous titres were at much lower levels (peak median titre 1 in 160) and lasted for a much shorter period (median survival 6 months) than the homologous titres (peak median titre of 1 in 480 and median survival of 9 months). This low level of cross-reactivity of the antibodies across serogroups of Leptospira is a known phenomenon and is the basis of including representative strains of multiple serogroups in the panel of antigens for MAT. This also indicates that the cross-protection offered by agglutinating antibodies is unlikely to extend beyond the infecting strain’s serogroup. New infections Out of the 231 patients in whom leptospirosis was ruled out and recovered, 114 individuals who volunteered and enrolled for the long-term follow up study were screened for a period of four years. Twenty two of these 114 patients developed acute febrile illness fulfilling the case definition of probable leptospirosis and a diagnosis of leptospirosis was confirmed in six patients. The intervals between the beginning of follow up and occurrence of the six events of infection among this cohort of 114 individuals occurred were 4, 9, 13, 13, 23 and 27 months. The cumulative incidence of leptospiral infection among this cohort of 114 individuals during the four year period of follow up was 5.26% and the incidence density was 1.32/100 person-years. The confirmation of diagnosis in the above patients was based on serology, using MAT on paired samples and/or isolation of Leptospira by blood culture. Out of these six confirmed cases, isolation was successful in one patient and the isolate was identified as belonging to serovar Valbuzzi of serogroup Grippotyphosa. In the remaining five patients the confirmation of diagnosis was based on serology. IgM antibodies were detected in all the 6 patients. Microscopic agglutinating antibodies were detected at the highest titre against serovar Grippotyphosa (Strain Moskva V) in 3 patients and against serovars Australis (strain Ballico) and serovar Icterohaemmorrhagia (strain RGA) in one patient each. Reinfection The individual initially infected with serovar Pomona, of the serogroup Pomona (confirmation was based on isolation and identification) was found to have re-infection due to serovar Ratnapura, of the serogroup Grippotyphosa (confirmation was based on paired MAT). Initial MAT showed fourfold rise in titre and the reactive serovar was

Grippotyphosa. Subsequent MAT was performed for seven serovars viz. Grippotyphosa, Ratnapura, Valbuzzi, Muelleri, Canalzonae, Huanuco and Vanderhoedeni under the serogroup Grippotyphosa as antigens and the highest titre of 1 in 1280 was observed against serovar Ratnapura, indicating that the infection probably was due to serovar Ratnapura of serogroup Grippotyphosa.