1 INTRODUCTION

Brucellosis is a bacterial zoonosis caused by various Brucella species, which mainly infect cattle, goats, swine, sheep, and dogs. Although several species of Brucella have been identified, the common ones include Brucella melitensis, Brucella abortus, and Brucella suis.¹ B. melitensis primarily infects goats and sheep; thus humans get infected by drinking their unpasteurized milk.² Brucellosis should be suspected in patients presenting with undulant fever and a history of intake of unpasterurized goat or sheep milk. Brucella and dengue coinfection is quite common. A study showed that among 37 serologically confirmed dengue cases, 8 showed coinfection with brucellosis. This can be attributed to either coinfection or cross-reactivity.^{3, 4} The coexistence of both infections is epidemiologically plausible in areas where both are endemic. However, the connecting link for the coinfection can be goat milk, which is widely consumed during dengue epidemics.

2 CASE HISTORY AND EXAMINATION

A 30-year-old, female living in the countryside presented with a complaint of high-grade fever, headache, and myalgia for 5 days. There was no history of cough, vomiting, rashes, and abdominal pain. Her past medical history was not significant. There was a history of dengue infection in her husband requiring admission 1 week back. On examination, the patient was well-oriented but was ill-looking. Her vitals included a temperature of 100°F, heart rate of 106 beats per minute, blood pressure of 90/60 mm Hg, and saturation of 97% in room air. Her systemic examination was unremarkable.

3 METHODS

The case required an approach for acute febrile illness in a tropical country where the causes of fever include respiratory infection, malaria, kala-azar, leptospirosis, brucellosis, chikungunya, dengue fever, scrub typhus, and other unreported illnesses.

Complete blood count showed a hemoglobin of 11.6 g/dL, total leukocyte count of 2600 with lymphocytic predominance, and a platelet count of 68,000 per cu. mm. No parasites or atypical blood cells were seen in the peripheral blood smear. Coronavirus disease (COVID) antigen and scrub typhus IgM/IgG were negative. Dengue NS1 antigen was positive. The patient was admitted with antipyretics and intravenous fluids. Her ultrasound abdomen was normal. She tested negative for kala-azar, malaria, and leptospirosis. On the third day, the patient was afebrile and requested discharge. She was hence discharged on oral acetaminophen. Six days after the discharge, the patient returned to the hospital again and mentioned that she was having a persistent fever. On detailed history-taking, she mentioned that her family had been taking black goat milk as a measure to increase platelet count. Her history led to suspicion of Brucellosis. B. melitensis antigen was positive and B. abortus antigen was negative. The patient was readmitted and was treated with oral doxycycline and intravenous gentamicin for 7 days.

4 CONCLUSION AND RESULTS

The patient responded well to treatment and was afebrile in 2 days. She completed intravenous gentamicin for 7 days in hospital and was discharged on oral doxycycline for total 6 weeks duration. She had good recovery without relapse during follow-up for 6 months.

5 DISCUSSION

Brucellosis is a global reportable multisystem zoonotic disease transmitted from infected animals like swine, goats, and cattle to humans via animal products, meat, or inhalation of agents. B. melitensis is the worldwide most common bacterial agent causing brucellosis.⁵ It commonly affects goats. Dengue fever is a mosquito-borne disease presenting as breakbone fever, myalgia, and arthralgia similar to acute brucella infection.^3-5 The coexistence of both brucellosis and dengue fever can be a cross-reactivity in serologic tests or a coinfection. The incubation period of brucella infection ranges from 5 days to 6 months.⁶ The unshakable mythical practice of consumption of raw goat milk among people of dengue endemic areas for boosting the platelet count can be a connecting link for diagnosis of brucella infection during dengue epidemics as seen in our case. Acute brucella infection can be acquired in a few days after dengue fever in an individual who has consumed raw goat milk for dengue fever. It may be a routine practice to send tests for common tropical diseases in endemic areas. However, such a practice is bound to add financial burden to the patients and hospitals during an epidemic of a particular disease. A simple question regarding the consumption of goat milk while taking history can clinch the diagnosis without extra expenses as in our case.

As there is no definitive antiviral for the cure of dengue yet, the role of herbal remedies like papaya leaves, kiwi, dragon fruit, and neem are being studied for dengue treatment.⁷ Goat milk is also widely used in parts of India and Nepal as a measure to increase platelet count. Goat milk is considered as an important source of selenium.⁸ Selenium content is high in platelets and it is also thought to inhibit platelet aggregation.⁷ While the effectiveness of goat milk in increasing platelet count is yet unknown, the escalating rise in dengue cases and platelet crises has been taken advantage leading to quackeries. An Indian national daily reported that the goat milk which was initially sold at 30 rupees per liter now costs 200–300 rupees per liter at different places of India.⁹ Such a myth of goat milk as a platelet booster increases the consumption of unpasteurized milk during dengue outbreaks. Goat milk is thought to have greater calories and better digestibility as compared to cow and human milk. However, its iron content is variable.^{8, 10} The traditional strong belief in nutritional value of goat milk seems to play a major role in creating strong belief in the context of thrombocytopenia in dengue fever as well.

Acute brucella infection and dengue infection share common clinical features and are difficult to differentiate clinically. Careful history-taking regarding unpasteurized milk intake is important and raises suspicion of brucella in dengue-positive individuals not responding to treatment. The role of goat milk in increasing platelet count is not scientifically proven. While we cannot restrict the intake of goat milk, the milk must be properly boiled before use. Thus, history of unpasteurized goat milk consumption is an important clinical consideration in recurring fever after dengue infection to clinch the diagnosis of brucellosis, especially in the areas where goat milk is strongly regarded as a platelet booster.

AUTHOR CONTRIBUTIONS

Shambhu Khanal: Conceptualization; data curation; writing – original draft; writing – review and editing. Prativa Subedi: Conceptualization; data curation; writing – original draft; writing – review and editing. Sushmita Bhandari: Writing – review and editing.

FUNDING INFORMATION

No funding source for this work.

CONFLICT OF INTEREST STATEMENT

The authors declare that there is no conflict of interest regarding publication of this case report.

ETHICS STATEMENT

Need for ethical approval was waived. Consent from the patient deemed to be enough.

CONSENT

Written informed consent was obtained from the patient to publish this report in accordance with the journal's patient consent policy. A copy of the consent form will be available for review if asked by editor in chief of journal.