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Leptospirosis An Occupational Disease Massey University Leptospirosis Research Group 6 March 2017
Leptospirosis An Occupational Disease
Massey University Leptospirosis Research Group
6 March 2017
Leptospirosis A global disease, a local phenomenon
Jackie Benschop and the Massey University Leptospirosis Research Group
6 March 2017
LEPTOSPIROSIS – An Occupational Disease
Sources: Albert Ko (Brazil), Milan Gautam (Nepal), Manawatu Standard, Eric Bertherat (India), Gauthier Dobigny (Niger)
Fig 2. Estimated annual morbidity of leptospirosis by country or territory.
Costa F, Hagan JE, Calcagno J, Kane M, Torgerson P, et al. (2015) Global Morbidity and Mortality of Leptospirosis: A Systematic Review. PLoS Negl Trop Dis 9(9): e0003898. doi:10.1371/journal.pntd.0003898 http://journals.plos.org/plosntds/article?id=info:doi/10.1371/journal.pntd.0003898
Annual disease incidence is represented as an exponential colour gradient from white (0-3), yellow , orange to red (over 100),
cases per 100 000 population.
Lepto is a disease of mainly poor and neglected communities
Mortality up to 10% Difficult to diagnose
Clinically Laboratory
Most fever was thought to be malaria
Source: Silais Chinandega, Nicaragua
A local phenomenon (NZ) Highly prevalent: cattle, sheep, deer (and mice)
Animal vaccination: a cornerstone for the prevention of human disease (this afternoon ….)
Human infection Exposure with no obvious disease
Mild to severe ‘flu Abattoir workers and farmers ~80%
Source: Marie Moinet, Shaan Mocke, RWNZ
“I had been fencing. In my joints, I felt sore and hot. I’ve got man flu coming on or something. That was at 4 o’clock. By 6 o’clock I was just lying on the bed, shaking and out-of-control. It absolutely flattened me.”
Persistent symptoms ~1 in 3 notified cases: fatigue, headaches, muscle pain,
sweats (6months + from acute episode) “And even now, if I go do something I get really exhausted, get a big sweat up and get puffed, the next day, couple of days, will be crap.”
Source: Goris et al, 2013, PLoS ONE; Shaan Mocke 2016
Occupation Seroprevalence#
(%) Risk Factors
Abattoir workers 10.9 (62/567) Worker position*
Farmers
6.6 (12/178) ^
Deer (wild and farmed), birthing assistance, flat terrain
Veterinarians 5.1 (14/277) Home slaughter (cattle and pigs) Mixed practice
Vet Students 0 (0/302) NA
#MAT titre cut-point ≥ 48 to Hardjobovis and /or Pomona (abattoir workers) and /or Ballum, Copenhageni , Tarassovi (other occupations) *common risk factor for sheep (n=4), beef(n=2) and deer(n=2) plants ^from 128 farms
Sanhueza et al. Zoonoses and Public Health 2016, Epi. and Inf. 2015; Dreyfus et al. Int. J. Environ. Res. Public Health 2014, Epi.and Inf. 2015; Fang et al. NZ Veterinary Journal 2012.
“Exposure ” in NZ workers
NZ long term trend in notified cases
0
100
200
300
400
500
600
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
Num
ber o
f not
ified
case
s
Year
In 2015 • Estimated burden (agricultural
and health) ~ NZ$ 24 m annually (Sanhueza J. PhD)
• 1.4 cases per 100,000 people. Moderate incidence for Asia/Pacific region (Victoriano et al, BMC Inf Dis, 2009)
Data Source: ESR
Data Source: ESR
0
10
20
30
40
50
60
70
80
90
95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15Year
Hardjo*
Ballum
Tarassovi
Pomona
NZ notified cases by serovar
Har/Pom reducing Bal/Tar steady (Increased use of PCR)
NZ 2015 notified cases
Source: ESR 2016
63 notified cases 60 lab confirmed 44 hospitalized Diagnosis 9 confirmed by PCR alone Increasing/Regional 36 farmer/ farm workers 9 meat processing 5 occupations with animal contact
Drilling down on occupation
Source: Cowie and Bell, NZMJ, 2012
Detailed occupational information is valuable
Increased cases Northland 2016
Data supplied by Dr Virginia McLaughlin, NDHB
2016 2015
Northland Leptospirosis Notifications, 1 Jan – 31 Dec, 2016
Serovars and Exposures
Source: Dr Virginia McLaughlin, NDHB
Notification Number Serovar Animal exposure Serology 14 Ballum
Pomona Tarassovi Ballum Tarassovi Ballum Ballum Ballum/Hardjo Ballum/Hardjo Ballum Tarassovi Ballum Ballum Tarassovi
Forest – ? possum/rats Dairy – herd was unimmunised (but also history of pigs previously on farm) Dairy - ?some new herd cattle unimmunised ? (non-farmer, lives rural – goats, cats, dogs on property) Dairy cattle - also wild pigs, ducks, dogs Retired - ? mice Possum – also pigs Possum – also deer Mice - ?rats ? (non- farmer lives rural) Beef cattle, horses, pigs, possums Rats ?Rats/mice Cattle (also rats in sheds)
Urine Pcr only 1 Unknown Rats Total 15
Detailed exposure information is valuable but people often have multiple exposures. Serovar information remains important but lepto DNA from sources and human cases will add to our understanding of where infection is coming from.
Wagenaar et al., 2013, Clinical Infectious Diseases
Knowing which sources and pathways are contributing the most to the disease burden allows targeting of intervention strategies.
Leptospirosis: a global disease, a local phenomenon
Complex: species, hosts and environments differ and change
Al McCone, NZ WorkSafe agriculture programme manager:
“vaccinate your animals, control rodents, practice good personal hygiene, use protective equipment, and get help early if you feel unwell”
We need to continue to work together
