PT  - JOURNAL ARTICLE
AU  - Dajem, Saad M. Bin
TI  - Molecular investigation of mixed malaria infections in Southwest Saudi Arabia
AID  - 10.15537/smj.2015.2.10874
DP  - 2015 Jan 01
TA  - Saudi Medical Journal
PG  - 248--251
VI  - 36
IP  - 2
4099  - http://smj.org.sa/content/36/2/248.short
4100  - http://smj.org.sa/content/36/2/248.full
SO  - Saudi Med J2015 Jan 01; 36
AB  - Objective: To investigate the incidence of mixed-species (MS) malaria infection, and compare the results with microscopically confirmed cases of malaria.Methods: During 2010, blood spots collected from 371 clinically suspected cases of malaria were microscopically examined in a cross-sectional study. The DNA was extracted from the samples, and a nested polymerase chain reaction (PCR) was performed. The results obtained by the 2 methods were compared.Results: From the microscopic analysis it was determined that 369 samples (99.5%) were positive for Plasmodium falciparum (P. falciparum) and 2 were Plasmodium vivax (P. vivax) mono-infections. There were no mixed malaria infections. The PCR analysis, however, showed that in 7 cases (1.9%) the infection was caused by MS malaria comprising of P. falciparum and P. vivax, 2 of these representing the cases that were microscopically diagnosed as P. vivax mono-infections. All cases were negative for Plasmodium malariae, Plasmodium ovale, and Plasmodium knowlesi.Conclusion: Mixed malaria infections are currently overlooked when using microscopy. The PCR assays are essential complementary techniques that should be used with microscopic examination of blood smears.