Sero-Prevalence and Risk Factors for Leptospirosis in Abattoir Workers in New Zealand

Abstract

Leptospirosis is an important occupational disease in New Zealand. The objectives of this study were to determine risk factors for sero-prevalence of leptospiral antibodies in abattoir workers. Sera were collected from 567 abattoir workers and tested by microscopic agglutination for Leptospira interrogans sv. Pomona and Leptospira borgpetersenii sv. Hardjobovis. Association between prevalence and risk factors were determined by species specific multivariable analysis. Eleven percent of workers had antibodies against Hardjobovis or/and Pomona. Workers from the four sheep abattoirs had an average sero-prevalence of 10%–31%, from the two deer abattoirs 17%–19% and the two beef abattoirs 5%. The strongest risk factor for sero-positivity in sheep and deer abattoirs was work position. In sheep abattoirs, prevalence was highest at stunning and hide removal, followed by removal of the bladder and kidneys. Wearing personal protective equipment such as gloves and facemasks did not appear to protect against infection. Home slaughtering, farming or hunting were not significantly associated with sero-prevalence. There is substantial risk of exposure to leptospires in sheep and deer abattoirs in New Zealand and a persisting, but lower risk, in beef abattoirs. Interventions, such as animal vaccination, appear necessary to control leptospirosis as an occupational disease in New Zealand.

Risk factors for new infection withLeptospirain meat workers in New Zealand

“…The higher risk of infection in workers at the beginning of the slaughter board and the gradual reduction along the slaughter line in sheep abattoirs is consistent with the seroprevalence data from this study described by Dreyfus et al 18 and with a study conducted 2 years earlier in one of the sheep abattoirs of the current study 19. Contact with contaminated droplets following urination due to stunning is thought to be a pathway for infection of workers at the head of the slaughter-board.…”

“…These findings were confirmed in the study on seroprevalence and risk factors by Dreyfus et al ,18 but contrast the findings of Heuer et al ,19 where home slaughtering was found to be a risk factor for seroprevalence.…”

“…The study population was recruited from a target population (the total number of workers who were asked to participate) of n=1747 (sheep), n=112 (deer) and n=814 (beef)18 and comprised all workers who were sampled at least twice. Some workers (n=57, 9.6%) in abattoir ‘sheep 1’ were sampled over two study periods, hence their infection rates were measured twice (up to four blood samples per participant).…”

Knowledge, Attitude and Practices towards Leptospirosis among Lakeshore Communities of Calamba and Los Baños, Laguna, Philippines

“…Agricultural workers engaged in crop farming, fish culture, and livestock raising and slaughtering are among the groups at high risk of acquiring leptospirosis because their work entails close contact with infected animals or urine-contaminated water and soil [13][14][15][16][17][18]. Moreover, agricultural workers typically lack awareness and basic knowledge of leptospirosis, hence making them more vulnerable to infection [19].…”

The impact of Livestock Manure Control Policy on human leptospirosis in Republic of Korea using interrupted time series analysis

“…Occupational exposure is also a significant risk factor in many countries and is particularly associated with agriculture and animal production (68% of total reported cases in South Korea, and 56·8% in Malaysia) [7][8][9][10][11]. In the Republic of Korea, rodents have been shown to be one of the major carriers of leptospirosis around swine farms; a survey in rodents conducted in 2008 found that 63·7% of rodents were infected [12,13].…”