Clinical features of malaria diagnosed in endemic area near Thailand-Lao border, Buntharik district, Ubon Ratchathani province, Thailand

Abstract

In 2014, the largest number of malaria cases was reported in Ubon Ratchathani province, especially in Buntharik district which is situated along the Thai-Lao border. This study was carried out to develop clinical criteria as guidelines to diagnose malaria in the endemic areas along the Thai-Lao border, Buntharik district, Ubon Ratchathani province and to investigate malaria infections in Buntharik district, Ubon Ratchathani province by using a microscopic method in routine settings and a nested PCR method. The results showed that of the 90 voluntary patients, the microscopic method identified 45 cases as infected with malaria parasites while the nested PCR method detected malaria parasites in 47 cases. The two additionally diagnosed cases were observed to be infected with P. vivax, whose parasite numbers in blood were lower than 50 cells/µL, thereby decreasing a tendency for malaria detection through microscopic technique. It was also found that two cases had a mixed-species infection of P. vivax and P. falciparum. It can be seen that the microscopy diagnosis, despite being a gold-standard method, has still suffered from such aforementioned limitations. Therefore, a molecular biological method has played a crucial role in detecting malaria parasites, given its higher sensitivity and specificity. In addition, the results revealed a correlation between clinical symptoms and endemic areas. The voluntary patients with fever, headache, and chill who reported visiting Chong Ta-Au Border Checkpoint were 9-10 times more likely to have malaria infections than other people. These data indicate that doctors must be alerted to performing the diagnosis of malaria in the endemic areas.  Although malaria cannot be microscopically diagnosed, re-examination and surveillance can increase a chance of malaria detections.