Malaria Prevalence in a Low Transmission Area, Jazan District of Southwestern Saudi Arabia

Abstract

Detailed description of malaria in low transmission areas is crucial for elimination. The current study aimed to provide a comprehensive description for malaria transmission in Jazan, a low transmission district, southwestern Saudi Arabia. Patients at a tertiary care hospital were recruited in our study between August 2016 and September 2018. Malaria diagnosis was performed through a species-specific nested polymerase chain reaction (nested PCR), microscopy and Paramax-3TM rapid detection test (RDT). Malaria was detected in 30 patients by the PCR, with point prevalence of 10.9%. Of these malaria infections, 80% was imported, 26.6% was asymptomatic and 23.3% was sub-microscopic. Malaria was reported throughout the year, with February/March and September/October peaks. Infection was significantly more in males than in females (P=0.01). Likewise, infections were detected more in febrile than in non-febrile patients (P=0.01). Adult aged 15-24 years, fever and travel were identified as high-risk factors. Malaria was primarily attributed to Plasmodium falciparum mono-infections, followed by P. vivax mono-infections and lastly to falciparum/vivax mixed infections accounting 76.6%, 16.6%, and 6.6% of PCR-confirmed malaria cases, respectively. The nested PCR was superior to the smear microscopy (sensitivity 76.6%; specificity 100%) and the RDT (sensitivity 83.3%, specificity 94.2%). The overall percent agreement between microscopy and the RDT was 92.7% (kappa=0.63). High proportion of imported malaria including sub-microscopic and sub-patent cases were described. We suggest that incorporation of molecular tool into the conventional malaria diagnosis is beneficial in Jazan district.

Keywords: Malaria diagnosis; Paramax-3TM; Saudi Arabia; nested PCR; sub-microscopic/asymptomatic infections.

Fig. 1

Map of Saudi Arabia showing the district of Jazan.

Fig. 2

Characteristics of the species distribution 30 malaria cases (A). (B) Proportions of imported and indigenous malaria in Jazan, 2016–2018. (C) Source countries/regions of imported malaria. (D) Age distribution of seven sub-microscopic malaria cases.

Fig. 3

Month-wise distribution of the reported malaria cases in Jazan, 2016–2018.

Fig. 4

A flowchart diagram shows results of three tests used for detection and characterization of the malaria cases in this study. RDT (Paramax-3^TM rapid detection test), LM (light microscopy) and PCR (nested PCR). ^a1 P. falciparum, 1 P. vivax and 1 mixed infections. ^b2 P. falciparum infections. ^c10 P. falciparum and 4 P. vivax. ^d2 P. falciparum and 2 P. vivax. ^e18 P. falciparum, 2 P. vivax and 1 as mixed infection.