Malaria Cases in a Tertiary Hospital in Kuala Lumpur, Malaysia: A 16-Year (2005-2020) Retrospective Review

Abstract

While there has been a tremendous decline in malaria disease burden in the remote parts of Malaysia, little is known about malaria incidence in its urban localities. This study aimed to analyze trends of malaria cases in urban Kuala Lumpur, Malaysia. All suspected cases presented to a university hospital in Kuala Lumpur from January 2005 to December 2020 were examined by microscopy. Infection status was analyzed using descriptive statistics and curve estimation analysis. Of 3105 blood films examined, 92 (3%) were microscopically confirmed malaria cases. Plasmodium vivax infections accounted for the majority (36.9%) of all malaria cases. Nearly half (47.8%) of cases were found among foreign cases (p < 0.001). The majority of foreign cases were male (86.4%) and came from Southeast Asian countries (65.9%). The curve estimation analysis showed significant decreases in malaria cases due to P. vivax (R² = 0.598; p < 0.001) and Plasmodium falciparum (R² = 0.298, p = 0.029), but increases for Plasmodium knowlesi (R² = 0.325, p = 0.021) during the 16 years. This study showed that malaria incidence in urban Kuala Lumpur is low and has remained stable since 2005. However, P. knowlesi has played a significant role in the increase in overall malaria in the area, highlighting the importance of continued vigilance and improved surveillance.

Keywords: Malaysia; Plasmodium knowlesi; incidence; malaria; retrospective; trends.

Figure 1

Trend in malaria cases at University Hospital of the National University of Malaysia (UKM) from 2005 to 2020. Error bar represents 95% confidence interval (CI).

Figure 2

Curve estimation model for malaria cases by (a) nationality and (b) Plasmodium species. Solid lines show model predicted prevalence and broken lines are 95% confidence intervals (CI).