Comparative seropositivity against leptospirosis between rice cultivators and non rice cultivators

Leptospirosis is an important disease of all vertebrates including humans. infection and/or disease may be caused by any of the 250 pathogenic serovars of the species leptospira interrogans arranged into 24 serogroups. the spirochete survives and propagates in the neutral or alkaline water. the occupational groups like veterinarians,butchers,sewer workers,farmers working in the rice paddy fields,hunters,fishermen soldiers and all others working in water are at the highest risk in contracting the disease. the organism enters the body through mucous membranes and causes fever,septicemia,arthralgia,cataract and abortion. treatment can be possible by administring doxycycline 100mg twice daily for 7-10 days. vaccine is also available. the disease is prevalent worldwide and five important pathogenic serovars are comprising of l. canicola,l. grippotyphosa,l. hardjo,l. icterohaemorrhagiae and l. pomona. a study was undertaken to understand the status of serovars distribution in the rice field workers. for this purpose five rice growing districts,i.e; sheikhupura,gujranwala,narowal,okara & sahiwal were selected. from each district,25 rice field workers and 25 matched non-rice field workers were selected. after venipuncture 5 ml blood serum was collected and used for slide macro agglutination test (smat) against five important serovars of l. interrogans (as mentioned above). a seropositivity rate of 80%,92%,72%,88%,and 84% was observed in rice field farmers in the sheikhupura,gujranwala,narowal,okara & sahiwal districts respectively. in contrast to that a seropositivity rate in non-rice growing farmers of sheikhupura as 20%,gujranwala 44%,narowal 40%,okara 48% & sahiwal 60% was observed. the results revealed that cumulative infection rate/seropositivity rate was higher in the rice field paddy workers as compared to non-rice field paddy workers. it may be concluded that the contaminated water with leptospira was the main source of risk for all those exposed to water,mixed with the urine of rodents,domestic and/or wild animals.