Etiological profile of fever cases admitted to a rural hospital - A 7 year study

Introduction

Acute febrile illness is defined as fever of duration less than 3 weeks and that which lacks an organ specific or localisable clinical feature.  A number of etiological agents like virus, bacteria, rickettsia, protozoa can cause AUF. The signs and symptoms are non specific and accurate diagnosis can be a challenge.The prevalence of local etiologies helps to analyse the differential diagnosis and guide the treatment. This uncertainity can lead to irrational use of antibiotics and anti malarial drugs. Since acute febrile illness can have overlapping aetiologies diagnosis and management of these cases can be a challenge. In tropical countries and endemic areas certain febrile cases can be diagnosed by simple rapid antigen testing some may require more sophisticated tests like polymerase chain reaction and ELISA. We study the common etiologies for acute febrile illness in the cases admitted to our rural hospital in this study, to give an insight in to the diseases endemic in this region so that the irrational use of drugs and diagnostic modalities can be prevented.

Materials and Methods

This study was undertaken in the rural hospital setting. It was a retrospective study wherein we analysed the case records of 2589 patients admitted to the hospital between January 2013- to December 2019. The cases with fever of > 101 degree Fahrenheit of less than 2 weeks duration were included in the study. A detailed history was taken including history of travel, drug abuse, sexual history and contact with animals. A detailed general physical and systemic examination was performed to look for any evidence of underlying etiological cause of fever. 6 th hourly temperature charts were maintained to look for pattern of the fever.

Results

The results were as follows. A total of 2589 cases of classical fever of unknown origin were observed in a 7 year period. There were 1786 males (69%) and 803 females (21%), with age ranging from 20 to 76 years.(Table 1) The mean duration of fever before hospitalization was 4 days. We observed that in our set up most of the cases of FUO were due to infectious diseases. Of the 2589 cases 64.73% were due to Dengue virus, 24.4% were of Plasmodium vivax aetiology. 4.17% were of plasmodium falciparum aetiology.In 3.01% both plasmodium falciparum and plasmodium vivax were positive.1.54% were due to hepatitis A, 1 % were due to leptospirosis, 0.03% were due to measles and 0.07% was due to tuberculosis.(Table 2) The incidence of Malaria in our study was less comparative to other studies conducted in India. The aetiological profile has changed from malaria being the most common cause of fever in the year 2013, 2014 to dengue fever from the year 2015 to 2019. Suggestive of change in the aetiology as dengue might now be endemic to this region surpassing malaria which was endemic earlier.

Discussion

Fever is one of the most important clinical signs. Fever of unknown origin (FUO) was first defined by Petersdorf and Beeson in 1961as a temperature above 38.3⁰C (101⁰F) on several occasions over a period of more than 3 weeks, for which no diagnosis has been reached despite 1 week of inpatient investigation1  Infection still remains the most common cause of FUO all over the world even though the demographics may vary from region to region. This was followed by connective tissue disorders (12%) and malignancies (12%).2 In the developing countries acute febrile illness is mostly due to infectious aetiology, either due to dengue or malaria .Investigation and treatment is then decided accordingly.

In India, although about 100 million individuals are investigated for malaria by microscopy every year, as per the official estimates only less than 2% of them are slidepositive. The annual slide positivity in malaria-endemic countries is estimated to be about 5% (6 million confirmed cases of 128 million individuals investigated in 43 countries).3, 4 A similar study in central India on Non malarial Acute Undifferentiated (NMAUF) cases revealed that about 39.9% patients with acute febrile illness received unnecessary treatment with antimalarial drugs.5 However our study indicates dengue as the most common cause for fever followed by malaria, hepatitis, leptospirosis and tuberculosis. No cases of scrub typhus were reported from our region. The regional prevalence of pathogens and their chances of exposure to the local people influence the disease pattern. Hence it is important to study the diseases endemic to the region to avoid unnecessary wasting of resources and finances by subjecting the patients to unnecessary laboratory investigations.

Conclusion

In our study dengue was the most common cause of acute febrile illness followed by malaria and hepatitis A. Other less common causes are leptospirosis, measles and tuberculosis.

Source of Funding

None.

Conflict of Interest

None.