Leptospirosis is a globally important, zoonotic bacterial disease with an estimated 1.03 million cases and 58,900 deaths annually, with tropical regions incurring the highest burdens.[[1]] Humans are infected from contact with animal urine or from contaminated water; contact with rodents and floodwater are recognised risk factors globally.[[2]] Patients with acute leptospirosis episodes (ALEs) have diverse symptoms, ranging from undifferentiated fever to fatal disease.[[3]] The clinical presentation is nonspecific, so diagnosis relies on attending clinicians being aware that leptospirosis could be a differential diagnosis followed by laboratory confirmation. Beyond the severe acute illness there are reports of post-leptospirosis symptoms (PLS) including malaise, fatigue and myalgia in the Netherlands;[[4]] uveitis in South India;[[5]] and chronic kidney disease and depression in patient cohorts in Taiwan.[[6,7]] In these studies, post-leptospirosis was variably defined from as little as 2 months after the acute episode up to 24 months. Goris et al. reported the duration of symptoms as 24 months or longer for 21% (12/57) of patients. The mechanisms underlying PLS may include persistent infection with Leptospira,[[8]] post-infective fatigue syndrome[[9]] or autoimmune conditions.[[10]] Current reports on long COVID bring the importance of documenting the long-term sequelae of infectious diseases in greater focus.[[11]] Choutka et al., in their 2022 review, coined the phrase post-acute infection syndromes (PAISs) to encompass viral, bacterial and protozoal infections where there is an unexplained failure to recover from the acute infection.[[12]] These authors recognise the overlap of the clinical features of PAISs with myalgic encephalomyelitis/chronic fatigue syndrome, suggesting a common etiopathogenesis.

Leptospirosis is also prevalent in countries with pastoral livestock industries like Aotearoa New Zealand (Aotearoa), as livestock contact is a recognised risk factor. Men working in agricultural industries, including meat workers and farm workers, are most reported as cases.[[13]] Serological diagnosis has been considered a gold standard [[14]] and predominates, however, PCR diagnosis is playing an increasing role. Serovars Hardjo-bovis, Ballum (both Leptospira borgpetersenii) and serovar Pomona (Leptospira interrogans) are most reported in Aotearoa. These reflect the restricted number of pathogenic Leptospira serovars known to be endemic in Aotearoa, all of which have arrived with domestic and wild mammals imported from the early 1800s.[[15]]

Leptospirosis is included in the list of occupational diseases recognised by the Accident Compensation Corporation (ACC), a Crown entity that administers a no-fault insurance scheme for injury by accident. People who develop leptospirosis resulting from their employment are eligible for cover, provided they satisfy the statutory and clinical criteria set by ACC. Over half of notified leptospirosis cases in Aotearoa are hospitalised[[16]] and approximately one quarter of these are admitted to intensive care.[[17]] The estimated annual cost of ALEs in Aotearoa is $4.42 million USD (95% PI 2.04–8.62) due to absence from work and disease treatment,[[18]] but this does not address the estimated 15-fold under-reporting of cases or the ongoing effects of PLS. While there is a paucity of documented information about PLS in Aotearoa and it is poorly recognised by ACC, there is high awareness of PLS in rural communities.

Our research programme in leptospirosis over the last 15 years has led to informal discussions with patients, physicians and workers and has identified two syndromes in approximately 30% of ALE patients: 1) “those who never came right”, who suffer fatigue, poor concentration and general malaise since their ALE, and 2) a headache/fever/myalgia triad that is intermittent for a variable period post-ALE. A 2009 case series reviewed 12 cases of chronic fatigue syndrome with a direct temporal link to a previous ALE contracted in Australasia. The 10 men and 2 women were meat processors (n=9) and farm workers (n=3), and the duration of their fatigue ranged from 6 months to 6 years at the time of last follow-up.[[19]] Three quarters of these (9/12) were 41 years of age or younger at the time of their ALE. All suffered disruption to their personal lives and work because of leptospirosis and its sequelae.

An earlier study was undertaken using semi-structured interviews and inductive analyses to explore the consequences for 10 New Zealand workers who had occupationally acquired leptospirosis.[[20]] These comprised nine men and one woman working in meat processing (n=8), farming (n=1) and truck driving (n=1) with 30% (3/10) under 40 years of age. Although PLS was not a focus of this work, ongoing fatigue was reported by all participants. Most reported at least one of the following long-term symptoms (up to 8 years post-ALE): migraines, irritability, depression, kidney problems, backache and sensitivity to light. Both immediate and longer term social (strained relationships), economic (lost income) and psychological consequences (fear of returning to work) were reported.

Globally, there is little information about the persistence of leptospirosis symptoms and whether some serovars are more likely to result in PLS. In Aotearoa, PLS is currently poorly, or not at all, recognised by ACC, thus documentation of patient experience with PLS will raise awareness of the condition and may also identify opportunities to improve systems and quality of care.[[21]] The aim of this pilot study was to perform an exploratory qualitative study with participants who were suffering from PLS to document their experiences.

Methods

Seven people who had previously been in contact with the first author to discuss their persistent symptoms of leptospirosis and who had expressly said that they would like to tell their stories were eligible to participate in this study. They were telephoned in late 2015 and were asked if they were willing to be involved in the study. Each participant who agreed to further contact was mailed or emailed a consent form, information sheet and an introductory questionnaire capturing demographic information, details of their leptospirosis infection or infections and their persistent leptospirosis. The introductory questionnaire was used to guide the subsequent semi-structured interview; it also specifically asked if the patients were aware of their serology (MAT titre) results. This is a paired blood test for leptospirosis, for which a diagnostic for confirmed leptospirosis is ≥400 or a four-fold rise in titre.[[22]] MAT results also give evidence of the likely infecting serovar. Serovar information has not been gathered in the context of persistent symptoms of leptospirosis in New Zealand previously.

Semi-structured interviews were conducted face-to-face by S.M.  in locations chosen by the participants. For three of the interviews, a study supervisor accompanied the interviewer but was not involved in the actual interview process. Questionnaire development was led by a clinical psychologist (J.L.)  who had experience counselling people with chronic conditions. The questionnaire and the structure of the interview were piloted on two individuals; the first being an employee at Massey University who had been diagnosed with leptospirosis at least 20 years ago and was suffering persistent symptoms. The second was an experienced farm animal veterinarian with good knowledge of the disease in animals and people.

All participants were offered the opportunity to have a support person with them for the interview, and a follow-up visit with their general practitioner was offered if they wished to know more about their condition or required further support after the interview. Interviews were recorded and a descriptive approach was used to analyse transcripts. Specifically, summative content analysis[[23]] was performed by two researchers (S.M. and J.W .) examining the text looking for recurring themes. Quotes from participants were included to support researcher inferences and provide evidence for the basis of the themes distilled from the interviews.

Prior to undertaking this research, the project was evaluated by peer review and judged to be low risk. Consequently, it has not been reviewed by one of the University’s Human Ethics Committees. The project was recorded on the Low-Risk Database, which is reported in the Annual Report of the Massey University Human Ethics Committees.

Results

All seven men who were approached initially agreed to be involved, although one of the participants withdrew from the study prior to the interviews commencing. During January 2016, the remaining six participants were interviewed either at their homes (n=4, Northland, Manawatū-Whanganui, Hawke’s Bay), a café (n=1, Hawke’s Bay) or at Massey University (n=1).

The participants were all male and ranged in age from 41 to 61 years old (Table 1). Five participants were in a long-term relationship and were interviewed with their partners. The other participant was interviewed on his own. Three of the participants had dependent children at home. One was in the same occupation as when first diagnosed with leptospirosis, two were currently unable to work and were at home full time and the other three were employed in part-time work. Four of the participants were hospitalised when they were initially diagnosed with leptospirosis. Laboratory test results for two of the participants (1 and 3) were viewed by the researchers. Participants reported infection with serovars Hardjo-bovis (n=3), Pomona (n=2) and one each of Copenhageni and Ballum.

View Table 1.

Individual participant summaries

Participant 1

This farmer was married with two young children when he was first ill with leptospirosis in 2011. Reported symptoms were fever and chills, headache, myalgia and extreme lethargy. He believed that he was developing “the flu” and spent 2 days in bed before seeing his local general practitioner. The following day, he presented at the local hospital where he was admitted due to dehydration. He was treated with fluids and intravenous antibiotics. Although his initial screening test for leptospirosis was negative, he was treated empirically for leptospirosis and medical records showed a second serum sample collected 2 weeks later had a MAT titre for Hardjo-bovis of 800. He reported being unable to work for the next 4 years due to fatigue, recurrent headaches, photophobia and myalgia (particularly in the legs and feet). He also reported mood swings. He was interviewed with his wife at Massey University, Palmerston North.

Participant 2

This participant reported fatigue, weight loss, back pain, myalgia (mainly in the legs) and proteinuria when first ill. He reported being treated with antibiotics for 9 months and not being hospitalised. In addition to the initial presentation, the patient reported further episodes of acute clinical disease in 2007 and 2010. The medical records for this patient were not available but he recalls testing in 2010 showed evidence of previous infection with Copenhageni and Hardjo-bovis. This patient reported that his situation over many years had been depressing and that he also suffered mood swings. The interview occurred at his home.

Participant 3

Acute leptospirosis symptoms were fever, vomiting, and back and loin pain for this participant. He was married with several dependent children when first ill. He was hospitalised where he was confirmed to be infected with Pomona (MAT titre 400). During his 9 days in hospital, he was diagnosed with hypotension, impaired renal function, pulmonary oedema and coagulopathy. At the time of interview, he had been unwell for 12 months with severe fatigue. He was one of three workers hospitalised in an outbreak of leptospirosis on a dairy farm in early 2015.[[24]] Cattle and pigs on the farm had serological evidence of recent infection with both Pomona and Hardjo-bovis, however, there was no evidence of clinical disease among the animals.[[25]] Ongoing symptoms included severe lethargy, headaches and visual disturbances. This participant had been unable to work since the initial illness. He was interviewed at home with his wife.

Participant 4

When first ill this participant’s symptoms were fatigue, tremors and photophobia. He spent 6 nights in hospital, 4 of them in intensive care. At discharge he was still suffering from impaired renal and hepatic function. He was confirmed to be suffering from leptospirosis due to Ballum 8 weeks after discharge. However, the medical records for this patient were not available. He had not been able to return to work and still suffered from fatigue and headaches. He reported needing to sleep for about 16 hours per day, and that he had no strength or stamina. The interview was at home with his wife.

Participant 5

This participant was working at a sheep slaughter plant when he first became ill with fever, vomiting, lower back pain and severe headaches. Although leptospirosis was suspected at the time, it was not confirmed. He was hospitalised and then transferred to a tertiary hospital for dialysis. He was in hospital for about 3 weeks in total, and unable to work for at least 2 months. His persistent symptoms consisted of severe headaches. In 2010, he became ill again with similar symptoms to the 1986 episode, including severe headaches, generalised muscle pain, fatigue and fever. Dilated cardiomyopathy was diagnosed in 2015, reportedly due to a “virus” that damaged the heart over a period. He is now unable to work in a physically demanding environment and is employed in office work. The medical records for this patient were not available. He was interviewed at a café in his hometown with his wife.

This patient’s father-in-law, daughter-in-law and several friends had also contracted leptospirosis through occupational exposure.

Participant 6

This worker first became ill while working in a deer slaughter plant. He reported extreme fatigue, fever, polyuria, photophobia, hyperacusis and tremors, and was noted by workmates to be jaundiced. This episode of disease was eventually confirmed by serology to be due to Hardjo-bovis. The medical records for this patient were not available. This patient was not hospitalised and was not treated with antibiotics for this episode of disease. He had a recurrence of acute disease in 2010, which was due to Pomona. After the initial episode of disease, he reported suffering symptoms for more than 10 years, which consisted of headaches (reported to be like migraines and occurring several times per month), photophobia, fatigue, myalgia (legs and back) and diarrhoea. He was interviewed at home with his wife.

Summative content analysis

The following themes were distilled from the interviews with the participants (and their partners in some instances).

These were hard-working men severely affected by the acute disease

All participants were working in physically demanding occupations prior to contracting leptospirosis. Their healthy lives, hard work and engagement with their communities were a source of pride and happiness.

It was full on, but I was loving it at that stage. You know I was pretty busy, with what I was doing, sports, different community things I was involved in. – 2

Participants reported classic symptoms of acute leptospirosis, especially rigours, myalgia, fever and extreme exhaustion. The sudden onset of symptoms was frightening to participants and their partners. Often men continued to work while feeling unwell.

He said to me “Well my muscles are sore, so sore”, and I thought it must be from bringing all the hay in, so normal. And pretty much 24 hours from then, on the Thursday, I was in town, and there was this funny message on the phone, get home quick, help! So I came home and found him passed out on the lawn, totally incoherent. – Partner of 3

It started with the chill in my back. And that must’ve been 2 to 3 hours before knock off. So I thought I would just hang in there, and do my evening shift clean up at the end of the day, and then I would sort it out when I got home. I just made it to the end of my shift, cleaning, and the pain was intensifying in my lower back. When I got home it came on over 5 or 6 hours, before I hit rock bottom. Yeah, massive headaches, migraines. And it felt like I had the flu, but about 10 times worse. – 5

Yes it happened at work, my mate said to me, I had really yellow eyes, I had no energy, and it just got worse. I finished the day out, but, um, over the next few days, it was really downhill. I was sweating and shaking, I had no balance, yeah, I was in a bad way. Any light, noises, loud noises, light specially, couldn’t tolerate it. – 6

Participants and their partners felt that medical staff who attended them during their acute episode had poor awareness, recognition and knowledge of leptospirosis

Participants reported that they were dismissed as having “the flu” or a virus. They had to suggest leptospirosis as a possible diagnosis to medical staff and they had to argue for a blood test or antibiotic treatment.

We went to the doctor and got a blood test done. And we had to argue that, for lepto, didn’t we? – 1

And the doctor we saw, she said he has a virus, he must toughen up. – Partner of 3

And I said, was it lepto... And he said, what’s lepto? And that’s when you think, oh shit. – 4

Post-leptospirosis symptoms were severely debilitating

Participants were exhausted, lost weight and they had aching muscles, brain fog and mood swings. Uncertainty about when or if they would recover fully, a sense of frustration and loss of self were apparent.

I get really achy legs. If my legs are too achy and sore, that’s an early sign. I got sore eyes from bright light … for the first 2 months out of hospital, even wore sunglasses around the house. I couldn’t stand any bright light. It drove me nuts. –1

Well by that stage I was just so exhausted and buggered. For that first probably 12 months, I was just a write off. – 1

Mood swings and depressions, mood swings are, that’s actually a really hard one... I mean, you do get pissed off. That level of frustration is so high. Or are you that pissed off that you can’t do anything? It is frustration, I think frustration is probably a symptom that needs to be clearly put in there. – 2

I have brain issues, from ongoing effects, especially when I get tired, it shuts down ... fuzzy thinking, fuzzy eyes, need to sit down, time for a break. You have no strength, and no stamina. You try to avoid walking every step, but then, after two months, you virtually have to train yourself to walk again. There was no way I could run, I was still falling over. Lepto eats you, and continues to eat you, until you have got nothing left. – 4

Even kind of now, I get really bad migraines, hey, really shocking migraines. I’ve got to go into a dark room for these headaches. I call them the dark room headaches. Probably about three times a month. The headaches are severe, very severe. – 6

Participants and their partners felt that the medical staff were poorly aware of PLS

This ranged from not believing that the patients were genuinely unwell or required any specific treatment, to a delay in requesting diagnostic tests or prescribing antibiotics, to not considering leptospirosis as a differential diagnosis.

Then one of the doctors said, these results on my blood screening were coming down and it was all in my head. – 1

[After an MRI] everything was perfect, and the other tests were perfect, walking okay etc. It was this neurologist at the private hospital that we saw, he said it was all in his head, just a waste of time. – Partner of 3

One time he had antibiotics, the other not, the first time he had nothing. I just had to look after him at home. – Partner of 6

Participants’ lifestyles and relationships were detrimentally affected by PLS

Participants reported the loss of careers and the ability to enjoy sport, they were short-tempered with their children and their partners had to pick up the farm work. Important relationships were affected, and participants recognised the stress that family members felt.

Work just stopped. It wrecked my career, it changed it—it stopped what we were doing, put it on hold. [Wife] went back to work full time. I looked after the kids. – 1

Given my time again, heaven forbid, the wrap-around thing would need to include support for the people supporting the patient … okay, you’ve got lepto, yes some antibiotics, go away but I want to see your family tomorrow, I want them in one room, I want to talk to them. The patient is fine, they’ve just got lepto. But you’ve got a wife thinking where’s the next paycheque coming from, the kids are thinking Dad is not much fun anymore, the volume goes up and up and up, and no one is listening. And the whole thing can become actually, turn to shit, pretty quickly. – 2

And I can’t do half the things I used to do with the kids. That’s the worst thing about it. And I get very short fused, when I start going down. The kids just vanish, because I lose it. – 3

He does lose his rag a lot quicker than he used to—still does, I don’t think that will change. – Partner of 4

I used to love golf. I still have not been able to achieve an 18-hole round, it was 2 years before I could swing the club. Oh, you would come to grips with it, but reluctantly you did accept. So I would go out, with intentions of going to have a game of golf, but after two holes I would be exhausted. – 4

Participants felt their employers and ACC were dismissive of PLS

Employers did not engage with the issue, or they tried to shift the blame to the employee. Sick leave entitlements were insufficient. Participants faced multiple barriers to a positive ACC experience: delay, lack of consistency, requirements to work very short hours and feeling that they were being labelled as a “bludger”.

ACC were just absolutely hopeless. I think I ended up with about 13 different case managers. I’d go there, and then get sent here, then make calls, and then I’d say I’m buggered and just go home, and sleep for a couple of days. I had to go to work 1 hour a day, and they were going to get me back into work. But it was like, who wants to hire someone for 1 hour a day, and I was going to travel for that, and to drive, I had to drive half an hour to get to work for 1 hour a day. And if I was tired and couldn’t do it, the driving was bloody hard on me. – 1

And I rang his employer and told them that he wasn’t well and they suspect it is lepto. And he said he shears sheep and does some home kill, that’s where he got it from, not from our cows. And then the third worker got it, three of them from the same farm. – Partner of 3

They wanted me back at work straight away. And then I went downhill again. They were only going to pay me a week sick leave and I had been there 3 years without a day’s leave! Then they said OK, maybe you can have 3 weeks’ sick leave—after all I had done for them! And then they put the screws on me to say, well ... they avoid me in town ... they want to hide it all under the carpet. – 3

It took 13 weeks for ACC to sort out our payments. Family of four, it was tough. – 3

I realised we may be entitled to ACC. So I rang ACC, they explained it to me, and they said they can’t initiate it. It has to go through your doctor. So we went to the doctor, and the reaction was less than desirable. Basically saying you are a bludger, you know, that kind of feedback we got. It was just like, then he went on his computer and said oh, there is something there for that. But we already had that first impression that we were bludgers for ACC support. – 4

Participants had valuable experiences to share

Participants advised others to protect themselves from risk such as making sure the livestock they were working with were vaccinated. They emphasised recognising the symptoms, acting quickly and resting well as part of the path to recovery.

Tell them not to work on an unvaccinated dairy farm. That information needs to be put out to workers. It’s not worth it, it’s 4 years and I’m just starting to get back into work. The boss doesn’t care, the boss just gets someone else in. You worked well, and then you got crook. You are just a number. I don’t mean that negatively, but that’s just the way it is. – 1

My biggest thing, and I tell other farming families, all of a sudden you’re feeling crook, stinking headaches and you can’t stand the light: lepto, get the drugs. That’s the one thing that annoys me, that I didn’t do something sooner. – 1

I would tell them to get it sorted, get antibiotics, take it easy, and fluids. – 6

Participants had some positive experiences due to PLS

Participants reported rising to a challenge, growth in confidence, time with family and embracing different community roles as a counterpoint to feelings of resignation and needing to keep going. Among meat industry employees there was a sense of improvement in relation to how the workplace responded to leptospirosis over time.

On the positives, I’m on the school board now, and I’m up at the school, because I was at home a lot, I ended up joining a few committees, and chairman of another outfit. I get to spend a lot more time with the kids, I’m a lot more involved with the community, and I’m a lot more confident, I am more confident at big gatherings to say something. – 1

What has kept me going … [silence] I think it’s psychological in the terms of, well, I want to get well. And there’s always going to be a tomorrow, and tomorrow might be the day that I get well. There is that aspect to it. It’s almost become a little personal thing, a challenge. – 2

I live for my kids, my family, our kids, I just wish I could do more with them. I suppose one way I’ve been able to spend a couple of hours at school with them, helping the school, helping the kids at school for a couple of hours. – 3

It’s different now, [at meat works company] now we have glasses, goggles, smock, everything, helmets, visors. It’s pretty good now. – 6

Discussion

This small pilot study has identified that leptospirosis contracted in the workplace can have severe long-term consequences for patients, their families and their communities. Patients and their partners felt unheard by medical staff, employers and compensation authorities. Our findings in relation to leptospirosis add support to previous work performed in Aotearoa[[19,20]] and in the Netherlands,[[4]] where it was identified that symptoms can persist long after the acute episode and these are associated with significant disruption to personal and work lives.

Participants experienced dramatic change in their lifestyles with only two of six returning to their pre-leptospirosis careers. While most workers who experience work-related illness or injury successfully reintegrate into the workforce,[[26]] our participants experienced complex employment patterns after their leptospirosis diagnosis and two were not working at the time of their interview. Workers in primary industries consider themselves staunch and stoic[[27]] and particularly within the farming community of Aotearoa the dominant stereotype is to be independent and self-sufficient.[[28]] That these men had little previous experience of illness and were working within the agricultural sector may have exacerbated feelings of anger and frustration at the disease, themselves and sometimes their families.[[29]]

Globally the burden and impact of work-related diseases and injuries are severely under-estimated[[30]] and specifically work-related chronic diseases have challenges associated with their recognition. Our participants felt their illness was inadequately recognised, investigated and treated and as a result felt dismissed by medical staff. This occurred when they sought help with both acute and persistent leptospirosis. Inadequate investigation may stem from a lack of recognition of leptospirosis by the attending medical practitioner. Awareness of leptospirosis in Aotearoa medical communities was identified as an issue in the results of analysis of semi-structured interviews with nine key influencers from agricultural industries.[[31]] Often participants or their partners needed to suggest leptospirosis as a differential diagnosis and then also suggest that a test needed to be performed. Inadequate investigation due to a lack of commonly agreed diagnostic terminology is a key factor in the poor recognition of chronic work-associated disease.[[32]]

Difficulties with investigating acute leptospirosis are further compounded by limitations in current testing protocols that make diagnosis difficult, even when leptospirosis is suspected and appropriate diagnostic samples are taken. A 2014 study identified that about a quarter of farm workers and meat workers presenting to general practice with flu-like symptoms will have leptospirosis, but even when the disease is suspected, they will not be diagnosed unless appropriately tested.[[33]] Reliance on paired blood sampling means that a large proportion of cases (84%) are not followed up and the diagnosis is never confirmed, nor included in surveillance notifications[[34]] We recommend ordering multiple laboratory tests during the acute episode to increase the likelihood of making a diagnosis. If acute leptospirosis is not diagnosed, or diagnosis is delayed, this potentially puts other workers in the same contaminated working environment at risk. It is possible to mitigate the risk of others contracting leptospirosis by taking swift corrective action, such as reducing contact with animal urine, increasing hygiene measures and treating infected animals with antibiotics.[[24]] Equally concerningly, and more so for the patient, if an initial diagnosis is not made there will be no medical record to link to subsequent symptoms.

Although participants reported having to ask for antibiotics, sometimes repeatedly, we have found that antibiotics are almost always prescribed when leptospirosis is suspected in Aotearoa. Thirty-nine of 41 patients suspected of leptospirosis were prescribed antibiotics in a 2014 study,[[33]] and antibiotics are recommended clinical management for leptospirosis globally.[[3]] Thus, not being prescribed antibiotics is likely to be largely due to a clinician’s lack of awareness of the disease rather than unwillingness to prescribe antibiotics for suspected leptospirosis. A key unknown is whether the timing of antibiotic treatment influences subsequent PLS. While current guidelines of not prescribing antibiotics when viral infections are suspected are useful in the toolbox of approaches to prevent antibiotic resistance,[[35]] it is also important to consider the impact of that guideline when bacterial disease is challenging to diagnose. We recommend that the current practice of treating on suspicion of leptospirosis continues.

In general, the impact of chronic disease on the families of patients is also often unrecognised.[[36]] Participants’ partners had major life changes including having to start work, moving to full-time work or taking up more responsibilities on the farm. In a mixed-methods research project involving case studies of injured or ill employees, the “hidden” costs borne by family and friends of the employees were discussed.[[37]] These included loss of closeness between partners and between parents and children, and spouses changing their work patterns. Being aware of and mitigating the effects of PLS on patients’ families will support patient recovery. Participants reported excellent family support and shared positive experiences including spending time with family, being more active in the community and facing the challenge of recovery.

Participants’ experiences with ACC were poor. A qualitative review into the cover decisions for work-related leptospirosis claims in Aotearoa identified that the crucial decisions affecting the claim outcomes were made by treatment providers and insurance claim assessors largely outside of the patient’s purview.[[38]] Each claim is assessed against two main requirements: having a confirmed diagnosis and having an appropriate exposure. While the criteria for the exposure are set in legislation, the diagnostic criteria may vary depending on factors like physician experience, laboratory test preference, and patient and employer compliance. A 2009 report analysing concepts of work-related harm found that the key to improving diagnoses was establishing systems to ensure that ACC claims are investigated by people with the appropriate expertise, as well as improving the occupational medicine training of general practitioners.[[32]]

The serovars reported by our study participants broadly reflect the general distribution of serovars in leptospirosis patients over the period these participants first became ill with leptospirosis.[[13,39]] A Dutch survey based on active case-finding reported an association between infecting serovar and likelihood of PLS, however, the time after the acute episode was shorter than in our study (2 months) and the infecting serovars in Dutch patients were not an exact match for those in patients from Aotearoa.[[4]] If infection with a particular serovar was a flag for persistence this could inform clinical decision making e.g., in managing patient expectations for recovery and in providing a broad support package of care around these patients. We recommend further investigations into this association.

Participants attributed their ongoing symptoms to their earlier diagnoses of leptospirosis, in some cases decades ago. However, how much of the ongoing expression is due to a constellation of predisposing, precipitating and perpetuating biopsychosocial factors, rather than a direct medical cause needs to be considered.[[40]] This enters an area of interface between medicine, psychiatry and psychology and includes the need to consider somatic symptoms and related disorders (DSM 5). In these conditions, symptoms typically persist after the normal expected trajectory of recovery from disease or injury and are medically unexplained. This area is poorly understood and the subject of ongoing research. Further, our participants “self-recruited” by reaching out to the lead author because of her research portfolio. They were seeking understanding and wanted to tell their stories and to be heard—and their stories relied on self-report and memory. While this bias needs to be considered, our findings are supported by international work and by interim findings from a current Aotearoa leptospirosis case control and case series study.[[41]] In this study 96 patients diagnosed with leptospirosis from September 2019 until December 2021 were enrolled. To date, one half (42/81) of these remained fatigued at least 9 months after disease onset and 20% had persistence of myalgia or headache. Twenty-five reported new symptoms they felt were due to their leptospirosis. These included urinary, renal and neurological concerns. All 13 participants who had a detailed semi-structured interview commented on their long duration of illness.

A further limitation we have considered is that the symptoms reported (exhaustion, weight loss, myalgia, brain fog and mood swings) occur in the general population. We have used data from the 2015–2016 New Zealand Health Survey to make a comparison.[[42]] Although we cannot perfectly match the symptoms and acknowledging our sample size (n=6) is small, we are confident that among the study population their symptoms occur more commonly than in the general population. For example, most adults completing the NZHS rate their own (88%) health as good, very good or excellent.

Another potential limitation of our study is that initial putative infecting serovar information was sighted by the researcher for only two of six patients and that there were no clinical notes sought. Further, we did look for biological markers of persistent infection or auto-immunity. However, as our aim was to perform an exploratory qualitative study to document patients’ experiences of PLS, we were not attempting to link experience with any documented clinical information.

Future research avenues include completing the initial follow-up for all of our current 96-patient cohort and continuing their follow-up for at least 5 years. This will elucidate the duration, severity and impact of PLS for the first time. Gaps in knowledge and awareness of leptospirosis were identified in this pilot study and future work to understand these gaps and to further knowledge and awareness is important. This includes disseminating the results of this study beyond traditional medical outlets to health psychologists, workplace insurers, occupational physicians and rural support groups.

Conclusion

Leptospirosis may have severe long-term consequences for patients, their families and their communities. We recommend that knowledge and awareness gaps in diagnosing the acute disease are addressed and that questions around aetiology, pathophysiology, biopsychosocial factors and burden be the topics of future research.