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.