Disease Description (Causes and Symptoms)
- Definition: Melioidosis is an infectious disease caused by the gram-negative bacillus Burkholderia pseudomallei. It infects humans and animals through environmental media such as soil and groundwater.
- Causes and pathophysiology: The bacterium enters the body through damaged skin (contact or penetration), inhalation (contaminated dust/aerosols), or ingestion. Because it can survive and multiply intracellularly, it may cause local abscess formation, hematogenous spread, and, in severe cases, sepsis and multiorgan damage. The incubation period varies from several days to several years.
- Main symptoms: Fever, chills, cough, difficulty breathing, and hemoptysis (when the lungs are involved), abscesses (in the skin, liver, spleen, etc.), general fatigue, muscle aches, headache, and symptoms of sepsis (low blood pressure, impaired consciousness), among others. It may present in a chronic or localized form and can be fatal in cases of severe pneumonia or sepsis (the case-fatality rate is high in severe cases).
Treatment Methods and Precautions
- Initial (intensive) treatment: In cases of severe or hematogenous infection, hospitalization and intravenous antibiotics are required. Standard medications (options) are as follows.
- Ceftazidime IV or a carbapenem (meropenem or imipenem) — recommended for severe cases/sepsis.
- The treatment duration varies according to the clinical presentation and severity, but is usually at least 10–14 days (extended in severe cases).
- Eradication treatment (oral maintenance therapy): Long-term oral treatment is required after intravenous therapy to prevent recurrence.
- Trimethoprim–sulfamethoxazole (TMP–SMX) is the standard, usually administered for 3–6 months.
- Doxycycline may be added or substituted when necessary (depending on the case, resistance, and tolerability).
- Surgical treatment: Drainage or excision may be necessary for localized or visceral abscesses.
- Supportive treatment: Intensive care for severe complications such as shock and respiratory failure (including fluids, vasopressors, and mechanical ventilation).
- Preventive vaccine: There is currently no commercially available preventive vaccine.
- Precautions (regarding treatment and self-care):
- Adhering to the treatment duration is important for preventing recurrence (the likelihood of recurrence is high with incomplete treatment).
- TMP–SMX requires caution or is contraindicated in cases of drug allergy, pregnancy (especially the first trimester), and severe renal impairment — clinical consultation is necessary.
- Patients with diabetes, chronic kidney disease, chronic lung disease, or immunosuppression have a higher risk of infection and severe disease and require early diagnosis and treatment.
- Difficulty breathing, persistent high fever, changes in consciousness, marked hypotension, severe hemoptysis, and similar symptoms require emergency treatment.
Checklist Before an Outpatient Visit (Preparation and Example Questions)
- Items/information to prepare:
- A record of when recent symptoms began and how they have progressed (fever, cough, difficulty breathing, presence of wounds or abscesses, etc.)
- Travel history (recent or past: endemic areas such as Southeast Asia, northern Australia, and Central and South America), and exposure history (mud, stagnant water, agricultural activities, exposure while barefoot, etc.)
- A list of underlying conditions (diabetes, kidney disease, chronic lung disease, immunosuppressive treatment, etc.)
- A list of current medications (including antibiotics and immunosuppressants)
- Previous test results (blood tests, chest X-ray/CT, culture specimen results, etc.)
- Examples of important information to tell the doctor in advance at the outpatient visit: the timing of and activities during recent overseas travel (rice paddies and fields, activities after flooding, etc.), whether there were any wounds, whether there are existing chronic diseases, and current medications
General Example Questions to Ask the Doctor
- What are the expected side effects of this medication (or treatment), and how should they be managed?
- How long will the treatment take, and what symptoms should prompt me to come to the hospital immediately during treatment?
- What is the risk of recurrence, and what lifestyle practices can reduce the risk of recurrence?
- I am pregnant or breastfeeding, or I have kidney disease. How will this affect the treatment plan?
Examples of Disease-Specific Questions
- I was exposed to soil and water in a region I recently visited (e.g., Southeast Asia/northern Australia). What tests (which specimens and what types of tests) would you recommend to determine whether I am infected?
- I have been diagnosed with pneumonia. If melioidosis is suspected, what are the criteria for selecting initial antibiotics and deciding whether hospitalization is necessary?
If you need further assistance, please provide your recent test results (cultures, imaging, blood tests, etc.), and we will organize more specific consultation questions and preparation requirements.