Case Series of Melioidosis in a Tertiary Health Care Centre in Puducherry, India

Melioidosis, a potentially fatal disease caused by the bacterium Burkholderia pseudomallei continues to be neglected in the Indian Subcontinent despite bearing about 44% of the global burden. Diagnosis poses a significant challenge since the disease presents a wide range of symptoms and closely mimics tuberculosis and pneumonia both of which are endemic in India. Sophisticated diagnosis and treatment often become unaffordable for patients from rural or low-income backgrounds. We present five cases of melioidosis from a tertiary care hospital (Mahatma Gandhi Medical College and Research Institute ) in Pondicherry that exhibited predominantly high-grade fever, abdominal pain, and vomiting. Radiological imaging revealed abnormalities in the brain (1/5, 20%), lung (3/5, 60%), liver (2/5, 40%), spleen (2/5, 40%), kidney (2/5, 40%), and prostate gland (1/5, 20%). Burkholderia pseudomallei infection was confirmed through blood culture. Treatment with meropenem or ceftazidime was initiated immediately. Neuromelioidosis was confirmed in one patient. The clinical diagnoses for the remaining cases were as follows: septic shock, melioidosis with urosepsis, and refractory shock. Three patients required intensive care and of the five, one patient was discharged, one died, and three discontinued treatments against medical advice. In the case of the deceased patient, the clinical diagnosis encompassed refractory shock accompanied by lactic acidosis, melioidosis, and community-acquired pneumonia, which subsequently progressed to acute respiratory distress syndrome (ARDS). Notably, this patient presented with co-morbidities, notably type 2 diabetes mellitus. This exemplifies the difficulty faced by patients from low-income backgrounds which forces them to discontinue expensive treatment. The true burden of melioidosis in the Indian Subcontinent is uncertain as many cases remain undiagnosed. Unawareness of the disease, low index of suspicion among medical professionals, incorrect treatment, and discontinuation contribute to the disease burden. It is therefore imperative that melioidosis is brought to the attention of healthcare policymakers to determine the true burden of the disease by prioritizing nationwide surveillance and diagnosis.


INTRODUCTION
Melioidosis, also known as Whitmore's disease, is a potentially fatal infectious disease caused by the saprophytic environmental Gramnegative bacterium Burkholderia pseudomallei, resulting in about 89,000 deaths per year.Melioidosis is predominantly a tropical disease, with the Indian subcontinent bearing 44% of the global disease burden. 1 It is, however, classified as a rare disease because of its similarity to tuberculosis, diverse clinical symptoms, lack of awareness among clinicians, and dearth of proper testing facilities. 2 The pathogen infects both humans and animals through direct contact with contaminated soil and water and can be naturally acquired through skin abrasion, ingestion, or inhalation. 3nvironmental factors like tropical storms and rain, and specific occupations like rice farming, increases the chance of exposure. 4,5Diabetes mellitus is the major risk factor along with chronic kidney, pulmonary, and coronary diseases. 2The mean incubation period of B. pseudomallei in humans is nine days but can vary from days (acute) to years (chronic) depending on risk factors, inoculum size, route of entry, and the presence or absence of virulence factors. 6Acute melioidosis manifests as pneumonia, multiorgan abscesses, and fulminant septicemia, whereas the chronic infection presents as symptoms mimicking tuberculosis (TB) with or without bloody sputum and multiorgan abscesses with occasional neurological involvement. 2,7However, unlike TB, scarring and calcification of the lungs are rarely observed in chronic melioidosis.The latent form of the disease may lie dormant for years, sometimes decades, and may reactivate in an immunocompromised state or with comorbidities including diabetes, renal failure, and alcoholism. 8. pseudomallei can be detected in blood, throat and rectal swabs, sputum, and pus from abscesses but their presence in clinical samples is limited.Melioidosis can be confirmed by culturing biological specimens in selective media and antimicrobial activity assays.However, care must be taken not to misinterpret results as Pseudomonas, Burkholderia cepacia, or Bacillus species, infections. 7Under light microscopy, B. pseudomallei appear as safety-pin-shaped bacilli which can be confirmed by immunofluorescence microscopy.Although very specific, these methods are limited in sensitivity. 9Serological tests like hemagglutination and latex agglutination coupled with ELISA can be used to screen for suspected infection but one should be cautious to avoid false positives from B. thailandensis infection and take into account differences in antibody titers from geographic areas. 10olecular diagnosis with PCR using 16S rRNA or B. pseudomallei-specific probes can be confirmatory.However, logistics and the availability of sophisticated instruments in rural areas limit the use of advanced molecular methods.Radiological imaging reveals multifocal nodular lesions in the lungs under X-ray and chronic infection may present lesions that resemble tuberculosis.Abscesses in organs, especially the liver and spleen, appear as a honeycomb pattern in computerized tomography (CT) scan.In neuronal involvement, magnetic resonance imaging (MRI) scan of the brain often shows ring-enhancing lesions and hyperintense changes but must be distinguished from cystic tumors by using diffusion-weighted imaging. 11he treatment of melioidosis follows a two-step regimen -an intravenous intensive phase and an eradication phase.The intensive phase of therapy (10-14 days) employs antibiotics like ceftazidime and/or carbapenems.The eradication phase commences after clinical improvement from the intensive treatment and the choice of drugs is a combination of trimethoprim-sulfamethoxazole (TMP-SMX) or amoxicillin-clavulanic acid for 3-6 months. 12ndividuals with open skin wounds, diabetes mellitus, and chronic kidney disease should avoid contact with soil and water, especially in endemic areas.Wearing boots can prevent infection of the lower limbs and feet.Patients presenting symptoms should be diagnosed with a high level of suspicion.Awareness among clinicians and healthcare workers can aid in the early diagnosis of melioidosis.
This case study underlines the recent increase in melioidosis in India and highlights the broad spectrum of clinical symptoms presented to better equip healthcare workers in diagnosing the  disease in its earlier stages.The need for sustained treatment for better recovery and eradication of the pathogen is emphasized.

Case Presentation
Within a five-month period from October 2021 to February 2022, a tertiary healthcare center in Puducherry, South India, treated five cases of melioidosis, predominantly affecting men (Table 1).Three had a history of type II diabetes mellitus (T2DM), and one suffered from chronic kidney disease.Chief complaints included high-grade fever, abdominal pain, and vomiting.Case 1 presented with blurring of vision and ear pain, alongside complaints of giddiness and headache.Case 2 experienced recent trauma while playing kabaddi, and Case 4 underwent incision and drainage of an arm abscess.All patients tested negative for COVID-19.Routine blood analysis revealed elevated white blood cell counts in three patients (Case 1, 2 and 3), thrombocytopenia (Case 2 and 3) in two, and urinary tract infections in two (Case 1 and 4).Radiological tests indicated lung ground glass opacities and hepatosplenomegaly in three patients, with hypodense lesions in the liver and spleen in one patient.One patient exhibited a cyst in the urinary bladder with prostatomegaly (Case 4).Case 3's brain MRI revealed an inflammatory granuloma with increased perilesional white matter edema, and a CT scan showed ill-defined hypodense lesions in various brain regions.A lumbar puncture of Case 3 indicated 430 cells/cu.mm(lymphocytes 80%, neutrophils 20%), suggesting CNS inflammation.Blood culture and antibiotic sensitivity tests (Table 2) confirmed B. pseudomallei infection in all five patients.Initially, broad-spectrum antibiotics were administered based on the initial diagnosis and symptoms.However, once B. pseudomallei infection was confirmed, all five patients were switched to intravenous meropenem (1-2 g) or ceftazidime (1 g) (i.v.) or a combination thereof within a week of their hospital admission.During the treatment course, Case 2, exhibiting asymptomatic and hemodynamically stable conditions, was discharged.Conversely, Cases 1 and 4, advised to continue medical treatment, opted for discharge against medical advice, citing logistical reasons.For Cases 3 and 5, the severity warranted intensive care, leading to admission to the intensive care unit (ICU).Unfortunately, Case 5 faced a fatal outcome during the intensive treatment phase.
Although, B. pseudomallei acute pulmonary infection was detected within 3 days of hospital admission and promptly started on i.v.meropenem, the patient developed sudden cardiac arrest on the 7th day preceded by bradycardia and could not be revived.This brings the mortality rate to 20% in the study, assuming the three patients who withdrew from treatment survived.

DISCUSSION
The present study reports five cases of melioidosis within a span of five months, describing the symptoms, diagnosis, treatment, and outcome at a teaching hospital in South India.Of the five patients, one patient (Case 2) was discharged after significant improvement.One patient (Case 5) died despite correct treatment 13 within 48 hr of hospital admission.Three withdrew from treatment against medical advice and their outcome is not known.This highlights a mounting problem in the treatment of melioidosis and probably reflects the high mortality rate due to this disease in India.All the B. pseudomallei isolates displayed susceptibility to the antibiotics when assessed using the MIC method (Table 2).Melioidosis is acquired generally from the environment and individuals exposed to contaminated soil and water are the most common victims.These often include people from low-income backgrounds especially daily laborers and farmers who often find it difficult to afford expensive medical treatment and hence discontinue medical advice.Since most primary and secondary healthcare centers including government hospitals are not sufficiently equipped to diagnose the disease, the true incidence of the disease may be an underestimate.Owing to diverse clinical presentations, diagnosis is surprisingly challenging, especially for rural health centers that lack awareness about the disease and proper infrastructure.Symptoms of melioidosis mimic other tropical diseases for which India is endemic and this exacerbates the issue further as the principal suspicion points to diseases like tuberculosis or pneumonia.
There has been a steady increase in melioidosis cases in India with a large number of reports from the southern parts of the country. 14,15The recent decade has witnessed an alarming rise in the number of cases with the highest of nearly 600 cases being reported last year. 8Whether this increase reflects a recent surge in incidence or diagnostic improvements, is unknown.However, there remains a significant lack of awareness and suspicion among clinicians and healthcare workers which often leads to misdiagnosis and incorrect treatment.Although a large number of scientific publications report the increase in melioidosis incidence in India, a national surveillance study to evaluate the exact number of cases and encourage the government to include melioidosis in health policies is largely lacking.A large-scale seroepidemiological study conducted in India reported a 29% seropositivity among adults in the Udupi district of Karnataka.Interestingly, however, seropositivity was similar in both farmers and non-farmers.Other factors like gender, socio-demographic status, occupation, and environmental factors were not correlated with seropositivity.However, it was also noted that the discrepancy in seropositivity rates and disease development may be dependent on the level of inoculum exposure.Also, high seropositivity does not necessarily mean a high incidence rate of melioidosis.A high antibody titer in some could also result from exposure to the closely related but non-virulent pathogen, B. thailandensis, that naturally inhabits soil. 16n the Indian Subcontinent, about 80% of melioidosis cases are diabetics.[17][18][19] Immunocompromised patients and those with chronic kidney disease (CKD) are more susceptible to the disease.20 Our study also indicates that diabetics and patients with CKD have a stronger predisposition to melioidosis. This ds in the differential diagnosis and patients presenting with high-grade fever, abdominal pain, vomiting, pneumonia, skin infections, and abscess with co-morbidities like type 2 diabetes mellitus (T2DM), CKD, liver disease, blood disorders, and cancer should be diagnosed with a high degree of suspicion keeping melioidosis in mind.In addition to the acute and chronic forms of melioidosis, B. pseudomallei can remain latent in its dormant state for many years.The major proportion of the bacteria may be neutralized by the host immune response in immunocompetent individuals or be eradicated incompletely by broad-spectrum antibiotics at sub-optimal doses.This paves the way for the recurrence of infection even after several years. 8 n a resource-limited country like India, especially the rural areas, diagnosing melioidosis which mimics other diseases, is a challenge.Awareness among clinicians and a strong suspicion can act as a primary diagnostic checkpoint enabling early transfer to higher centers of care thereby preventing misdiagnosis and incorrect treatment.Microbial culture analysis remains the gold standard for B. pseudomallei identification.However, it is often time-consuming and requires selective media like Ashdown agar that rural laboratories hardly have any access to.Sophisticated techniques like mass spectrometry, PCR, and sequencing may also be used to identify B. pseudomallei infection and genetic variants if any.These techniques are also, however, restricted to higher research centers and medical laboratories.Successful treatment requires prolonged administration of expensive antibiotics that have proven effective even in deep-seated infections.Patients from rural or low-income strata of society can seldom afford such treatments and often discontinue resulting in relapse.21,22

CONCLUSION
Melioidosis remains to be a neglected disease in India and is not under the purview of the Integrated Disease Surveillance Program (IDSP) run by the Indian National Center for Disease Control (NCDC) despite a higher predicted number of global deaths than dengue and leptospirosis which are among the top 12 priority diseases of IDSP.Melioidosis, therefore, warrants more critical attention from the health ministry and can only be achieved through a consorted approach by researchers and medical professionals to pool their resources and present the true nature of the disease in India.The recent surge in melioidosis cases in India has prompted active initiatives by institutes like Kasturba Medical College, Manipal, India, leading to the inception of the Indian Melioidosis Research Forum (IMRF).IMRF aims to rope in regional health centers and network with centers in other South as well as South East Asian countries to monitor and enhance communication about the disease to assess the true burden of the disease and bring it under the attention of policymakers.

Table 1 .
Underlying conditions, clinical manifestations, and outcomes of patients with melioidosis Patie Age/ Sex Clinical