The disease progresses rapidly after seeing a doctor due to fever and muscle pain. How is it diagnosed?

Yimaitong compiles and organizes, please do not reprint without authorization.

Case data: The patient is a 59-year-old male.

Mainly due to fever and muscle pain (mainly lower limbs and waist) aggravated in 5 days with vomiting and abdomen is not suitable for emergency treatment.

The patient suffered from high blood pressure in the past and had moderate alcohol consumption.

The patient has no recent travel or animal contact history living in urban areas, and he has been to rural areas near his place of residence.

The vital signs and physical examination were normal on admission.

Blood tests showed anemia (hemoglobin 11.
9 g/dl), elevated levels of inflammatory markers (WBC 10300 /L, C-reactive protein 37.
7 mg/dL), thrombocytopenia (PLT 56000/L), and acute kidney injury (creatinine 2.
39 mg/dl), increased creatine kinase (CK 288 U/L) suggests rhabdomyolysis, hepatolysis and cholestasis (transaminase: TGO 291 UI/L, TGP 99 UI/L, glutamyl transpeptidase [GGT] 101 UI/L, total bilirubin 1.
46mg/dl), lactic acid level increased (3.
24 mmol/L).

Urinalysis revealed proteinuria (150 mg/d) and hematuria.

Ultrasonography of the kidneys was normal.

The patient is suspected of sepsis with multiple organ dysfunction.
Blood is collected for culture and serological examination of bacteria and viruses, and fluid therapy is initiated to improve lactic acid levels and rhabdomyolysis.

However, the patient's condition deteriorated rapidly and was transferred to the intensive care unit (ICU) for invasive ventilation, vasopressin support, and continuous renal replacement therapy.

Based on the patient's flu-like symptoms and laboratory test results, suspected zoonotic disease, began to use doxycycline and meropenem for empiric antibiotic therapy.

Blood culture and serological examination of bacteria and viruses, enzyme-linked immunosorbent assay (ELISA) Leptospira-specific IgM was negative.

The PCR test for leptospirosis was positive, and the diagnosis was finally confirmed.

The patient received doxycycline treatment for 8 days and was discharged from the hospital on the 14th after clinical improvement.
There was no sequelae.

Analysis and discussion Leptospirosis is abbreviated as Leptospirosis, which is an acute animal-derived disease caused by pathogenic Leptospira.
It has a variety of pathogenic types and serotypes.
Indirect contact is the main reason for most sporadic cases.

The typical manifestations of leptospirosis are three symptoms (fever, muscle aches, fatigue) and three signs (conjunctival hyperemia, gastrocnemius tenderness, and lymphadenopathy).

Most symptoms can appear within 5-14 days after exposure, and clinical diseases can also suddenly onset after an incubation period of 2-30 days.

The symptoms of leptospirosis can be divided into two stages.
The initial stage (acute phase/sepsis) starts quickly and lasts for 5-7 days.
The main manifestations are non-specific symptoms similar to mild flu (fever, myalgia, headache) , And then showed a relatively asymptomatic state.

The second stage is the appearance of antibodies in the serum.
Leptospira can be excreted in the urine (immune stage).
Most complications occur at this stage (the second week of illness).

Leptospirosis is prevalent all over the world.
Due to the continuous changes of the climate environment, population migration and other reasons, the incidence rate is low, and clinical misdiagnosis is extremely easy.

Clinical diagnosis not only needs to be based on epidemiological exposure, but also based on clinical manifestations consistent with the disease.

A complete medical history and physical examination are the key to an accurate diagnosis of the disease, combined with the results of non-specific laboratory tests, such as leukocytosis, thrombocytopenia, rhabdomyolysis, renal failure, hepatolysis and cholestasis with hyperbilirubinemia , Such as the performance of this patient, can only suggest leptospirosis but cannot be diagnosed.

Although IgM ELISA is usually used as a standard serological test, a negative result in highly suspicious patients should not exclude the possibility of diagnosis, because antibodies only appear during the immune phase.

In addition, antibody positivity can last for months or even years, and PCR testing can confirm the diagnosis in the early stages of the disease before the antibody titer reaches a detectable level.

PCR detection is a rapid, sensitive and specific detection method that can be clearly diagnosed in the acute phase of the disease.

The initial management of patients with severe clinical leptospirosis includes active intravenous fluids to improve dehydration and shock.

In the case of moderate to high clinical suspicion but lack of a clear laboratory diagnosis, empirical treatment can be initiated.

Doxycycline is effective for eliminating leptospiraemia and treating bacteria-carrying state.

The prognosis of leptospirosis mainly depends on the involved organs, the pathogenic serotype, and the characteristics of individual patients and comorbidities.

The mortality rate of critically ill patients ranges from 5% to 15%, increasing when treatment is not started within 2-3 days of onset.

The mortality rate of patients with severe pulmonary hemorrhage can exceed 50%, so early diagnosis and appropriate treatment are essential to improve the prognosis of patients.

References: 1.
Brito Monteiro M, Egídio de Sousa I, Piteira M, et al.
(April 05, 2021) Leptospirosis, a Re-emerging Threat.
Cureus 13(4): e14295.
2.
Lin Hairong, Chen Fenglin.
Chigger Leptospirosis complicated with 1 case.
Infectious disease information.
2021.
34(1): 87-89.
3.
Chen Wei, Zeng Yanping, Ma Weixing.
A case of pulmonary hemorrhage induced by Leptospirosis Herxian reaction.
Modern Practical Medicine.
2020.
32(3) :418-420.