Persistent renal replacement requirement following fulminant psittacosis infection in pregnancy

Abstract

Chlamydia psittaci is a zoonotic bacterial infection that most commonly causes mild flu-like symptoms in humans. However, in pregnancy, it can present as fulminant psittacosis associated with systemic illness, disseminated intravascular coagulation, renal and hepatic failure. We describe a case of a veterinary nurse in her 30s who presented at 32 weeks’ gestation with rapidly progressive multiorgan failure, with positive, C. psittaci serology. Further history revealed that she had delivered a number of dead lambs in the preceding weeks to her illness, highlighting the importance of a thorough social history. C. psittaci should be suspected in the differential as a causative organism for severe pneumonia with multiorgan failure particularly in pregnant women with animal or bird contacts.

Background

Exposure to zoonotic infection in pregnancy can have severe consequences. Chlamydia psittaci is a zoonotic infection that should be part of the differential diagnosis in pregnant women exposed to livestock and in whom a severe pneumonia manifests. Sometimes these cases require repeat testing as initial results can be inconclusive. Early and aggressive antimicrobial treatment of suspected C. psittaci is needed to reduce the risk of maternal and fetal morbidity and mortality. Multidisciplinary involvement between obstetricians, intensive care specialists, microbiologists and infectious disease specialists, renal physicians and neonatologists were paramount in the management of this case. This case highlights the necessity to take a thorough clinical history including occupational history in presentations of severe multiple organ failure and also presents a rare care of persistent renal impairment post C. psittaci infection.

Case presentation

A gravida 3, parity 2 pregnant woman in her 30s with previous uncomplicated pregnancies and no significant medical history was admitted to hospital at 31+4 weeks gestation after a 4-day history of headache, fever and mild shortness of breath. She worked as a veterinary nurse and owned livestock in a smallholding. On admission, she had a sinus tachycardia of 140 beats/min, blood pressure was 115/65 mm Hg and she was tachypnoeic with a respiratory rate of 28 breaths/min. She initially had no oxygen requirement. Mild bibasal crepitations were heard on auscultation.

She was treated for chest sepsis with broad-spectrum antibiotics and intravenous fluids. Cardiotocography (CTG) at the time was reassuring so she was admitted to a high dependency unit for monitoring. Blood tests on admission showed a pancytopenia with high C reactive protein and deranged liver function tests (table 1). Initial imaging included a chest radiograph, which showed some bilateral interstitial shadowing. Arterial blood gas showed a raised lactate (10 mmol/L) and a severe metabolic acidosis.

Table 1.

Blood results during admission

Blood results	Reference	Day 1	Day 2	Post partum	Day 3	RRT started	Day 4	Day 5	Day 7	Day 10
Hb g/L	>105 (second and third trimester)	100	84		72		82	74	81	64
Platelets × 109/L	150–400	75	19		12		6	14	23	76
WCC × 109 /L	6–16	3.8	1.2		3.5		4.1	8.8	10.0	8.7
Lymphocyte count × 109 /L	1–4	0.1	0.1		0.5		0.7	1.4	1.9	2.3
Serum creatinine μmol/L	< 75	64	128		262		211	190	216	272
Serum ALT IUL	6–32	100			137		137	162	102	44
Total bilirubin μmol/L	< 22	47	80		106		95	77	23	26
Serum albumin g/L	28–37	34	24		29		29	30	28	33
Serum CRP mg/L	< 5	220	232		280		217	121	191	126
Serum PCT μg/L	< 0.5				21.85			13.97	6.13	2.02
Serum LDH IU/L	140–280	327
Haptoglobin g/L	0.3–2.0	1.11

ALT, alanine transaminase; CRP, C reactive protein; Hb, haemoglobin; LDH, lactate dehydrogenase; PCT, procalcitonin; RRT, renal replacement therapy; WCC, white cell count.

Within 24 hours, she developed significant oxygen requirement and a marked lactic acidosis with subsequent pathological CTG. She required intubation and ventilation and was taken for an emergency caesarean section. The baby was born alive but unwell and transferred to neonatal intensive care. There was no significant blood loss intraoperatively; however, a platelet transfusion was required. A subsequent CT thorax (figure 1) showed extensive consolidation in the lower lobes of both lungs with small adjacent pleural effusions.

Figure 1.

CT chest.

Post partum, she became anuric with significant acute kidney injury and went on to require continuous renal replacement therapy (RRT) (table 1). She was persistently anaemic and pancytopenic. She required inotropic support with a norepinephrine infusion (initially at 10mls/hour) and fluid boluses for hypotension which was weaned during the admission. Given her presentation of anaemia and thrombocytopenia, differential diagnoses included thrombotic thrombocytopenia purpura, haemolysis, elevated liver enzymes and low platelet (syndrome), microangiopathic haemolytic anaemia, haemophagocytic lymphohistiocytosis and disseminated intravascular coagulopathy. All screens were negative, with a normal fibrinogen and her ADAMS-13 protein returned back within normal limits. Haemolysis screen was negative with only mildly elevated LDH, normal haptoglobin and no evidence of haemolysis on the blood film (table 1). She did not have notable proteinuria or haematuria on urine dipstick.

On further questioning, it was reported that she had delivered a number of dead lambs in the preceding weeks to her illness. Extensive testing ensued looking for the pathogen responsible for her illness. Serum cultures were positive for C. psittaci on the second sample.

Treatment

Prior to getting positive serology, she was treated with broad-spectrum antibiotic therapy initially with piperacillin-tazobactam, clarithromycin, ceftriaxone and doxycycline for 72 hours to cover for possible zoonotic infection, which was then switched under microbiology advice to meropenem and ciprofloxacin, where she received an 8-day course.

Outcome and follow-up

Her pneumonia resolved with antibiotics, and she was extubated after 7 days. The thrombocytopaenia resolved but she remained persistently anaemic. She continued to be anuric, requiring RRT and was transferred to the renal unit to continue haemodialysis. She continues dialysis at 16 months after her initial presentation. She has completed a process of preparation for kidney transplantation and is now active on the national deceased donor transplant list. Her baby has been discharged from the neonatal intensive care and remains well. Serum titres of C. psittaci resolved with antibiotic treatment.

Discussion

This case describes a rare complication of fulminant gestational psittacosis resulting in the need for long-term RRT. Psittacosis is caused by the organism C. psittaci and is a cause of community acquired pneumonia and rarely extrapulmonary organ failure. Traditionally, it has been largely linked to avian zoonotic transmission; however, studies have shown a link with non-avian animals.^{1 2} Human-to-human transmission has been described^{3 4} but is rare. It is suspected that our patient contracted the infection through contact with stillborn farm animals. C. psittaci is a known cause of fetal loss in ewes, with cases of zoonotic transmission reported during lambing period.⁵ Typically, humans become infected through aerosol inhalation when exposed to infected species, often presenting with features of a flu-like illness with headache, myalgia and rigours.^{6 7} However, on occasion, it can take a more fulminant course⁸ with reports of respiratory illness requiring mechanical ventilation,^{9 10} hepatic injury¹¹ and acute renal failure¹² as observed in our case. Treatment includes the early administration of antibiotics, of which doxycycline is first line.¹³ Psittacosis is now rarely fatal with early administration of antibiotics, but mortality is 15%–20% without their use.¹⁴

Gestational psittacosis describes multiorgan failure (predominantly pulmonary and hepatic) with coagulopathy, associated with fetal loss, largely reported due to close contact exposure of pregnant women to with infected products of conception.¹⁵ A recent retrospective study analysed 23 published case reports of gestational psittacosis.¹⁶ Most cases occurred in the third trimester of pregnancy, and unlike psittacosis affecting the non-pregnant population, a majority (17/23) of cases were associated with sheep rather than avian sources. There was a high fetal mortality rate (19/23) in documented cases, with no cases of successful fetal carriage to term. Improvement in maternal condition was seen post delivery of the placenta in most cases supporting the suggestion that the placenta acts as a sanctuary site¹⁷ meaning antibiotics may be ineffective without placental delivery and therefore early obstetrics involvement is important in these cases. Close contact between pregnant women with infected animals, notably sheep and goats during birthing season, should be avoided.¹⁸

Of published case reports, there are no documented cases of gestational psittacosis requiring RRT, despite over half of cases having evidence of renal impairment.¹⁶ There have been several cases describing renal failure requiring RRT in the non-pregnant population. In surviving patients, restoration of renal function is commonly seen, and this is the first case that we know of, which describes long-term loss of renal function with ongoing dialysis dependence. A range of different aetiologies have been suggested to be associated with this observed renal impairment though there is limited histological evidence. Two cases of Psittacosis have been described with oliguric renal failure requiring peritoneal dialysis and intensive care support. In both, acute tubular necrosis of the kidneys was found on postmortem examination.¹⁹ Fulminant psittacosis complicated by acute renal failure requiring haemofiltration for 28 days with resolution after this period has also been described.²⁰ In cases where renal biopsy has been performed, histology has shown tubular interstitial nephritis²¹ and acute glomerulonephritis.^{12 22}

As the most likely aetiologies of kidney injury are driven by sepsis which had resolved, and as the patient’s preference was to avoid further invasive procedures, histology to confirm the cause of renal injury was not available. Given the thrombocytopenia observed, thrombotic microangiopathy might be a differential; however, we did not see any evidence of red cell fragmentation on blood film which is one of the hallmark features.²³ Further differential diagnoses for the acute kidney injury included acute tubular necrosis, hypoperfusion injury, C. psittaci-associated glomerulonephritis and tubulointerstitial nephritis.

Patient’s perspective.

‘I don’t really remember too much leading up to my stay in ICU, after I came out of my coma and the drugs started to wear off, I was very weak and confused. The whole ICU team were amazing the nurses helped me wash, brush my hair and were never far away and were happy to do and help me with everything. I really liked the memory boards which reminded me of things I liked, the nurses wrote the day on them and what the weather was like etc, my husband brought pictures in of the family which was good to see. The doctors were amazing too, explaining my treatment and plan and everyone looked after my husband too. I remember meeting my gorgeous little boy several times in ICU before being moved to the renal unit. I’m currently doing twice a week dialysis which is becoming part of our normal daily life routine. I’m on the donor list and we are going to look at live donors as well. I’m doing so much better getting stronger and enjoying life, we are off to conquer Mount Snowdon in May fingers crossed I will make the top (it’s been a goal since coming out of hospital)! Also, my baby boy is just fabulous, fit, and healthy and adored by his big sisters and the family.

Learning points.

• Detailed clinical history, with a focused social history, is required for acute presentations with respiratory illness.

• Fulminant psittacosis is a rare cause of severe multiorgan failure. Renal failure is often limiting but may require renal replacement therapy and long-term dialysis dependence.

• Gestational psittacosis carries an increased risk of a fulminant course which can be life threatening and is associated with high fetal loss. Unlike in the non-pregnant population, it may more commonly be associated with a non-avian source and therefore pregnant women should avoid close contact with birthing farm animals notably sheep and goats.

Ethics statements

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