Indian Journal of Critical Care Medicine
Volume 25 | Issue Suppl 2 | Year 2021

Laboratory Diagnosis of Tropical Infections

Shaoli Basu1, Anjali Shetty2

1,2Department of Microbiology, PD Hinduja Hospital, Mumbai, Maharashtra, India

Corresponding Author: Anjali Shetty, Department of Microbiology, PD Hinduja Hospital, Mumbai, Maharashtra, India, Phone: +91 9870111210, e-mail:

How to cite this article: Basu S, Shetty A. Laboratory Diagnosis of Tropical Infections. Indian J Crit Care Med 2021;25(Suppl 2):S122–S126.

Source of support: Nil

Conflict of interest: None


Highlights: (1) Blood culture is the gold standard for the diagnosis of bacterial infections. (2) Bone marrow culture is more sensitive than blood culture even in patients with enteric fever receiving antibiotics. (3) Microscopic agglutination test is considered the gold standard for diagnosing leptospirosis; however, now IgM ELISA and polymerase chain reaction (PCR) are more frequently used for diagnosis. (4) Tuberculosis is diagnosed with the help of nucleic acid amplification tests like Xpert MTB/RIF Ultra which also detects rifampicin resistance. Other tests include microscopy, Lowenstein–Jensen and mycobacteria growth indicator tube culture, line probe assay. (5) Tropical rickettsial infections are diagnosed by serological reactions (Weil–Felix, ELISA for antibodies) and PCR. (6) For Brucellosis culture from blood, bone marrow or tissue specimens remain the mainstay in diagnosis. (7) Dengue, Zika, Crimean–Congo hemorrhagic fever, Ebola, hantavirus, rabies are diagnosed with reverse transcriptase-polymerase chain reaction. Serological tests like IgM ELISA or paired sera samples for IgG are also used for diagnosis.

Keywords: Brucellosis, Dengue, Ebola, Enteric fever, Leptospirosis, Rickettsial diseases, Tropical infections, Tuberculosis.


Tropical infections are those which are prevalent in tropical and subtropical regions. “Ending the neglect to attain Sustainable Development Goals: a road map for neglected tropical diseases 2021–2030”—a 10 years plan was formally launched by WHO in January 2021.1





Early diagnosis has an impact on patient management. Our diagnostic armamentarium is increasing and we are moving from complex time-consuming tests to rapid diagnostics. However, we need more reliable point-of-care tests for prompt diagnosis and management of tropical infections.


Shaoli Basu

Anjali Shetty


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