Plasmodium cynomolgi Co-infections among Symptomatic Malaria Patients, Thailand

Chaturong Putaporntip,Napaporn Kuamsab,Sunee Seethamchai,Surasuk Yanmanee,Urassaya Pattanawong,Somchai Jongwutiwes

doi:10.3201/eid2702.191660

Abstract

Among 1,180 symptomatic malaria patients, 9 (0.76%) infected with Plasmodium cynomolgi were co-infected with P. vivax (n = 7), P. falciparum (n = 1), or P. vivax and P. knowlesi (n = 1). Patients were from Tak, Chanthaburi, Ubon Ratchathani, Yala, and Narathiwat Provinces, suggesting P. cynomolgi is widespread in this country.

Highlights

Plasmodium cynomolgi, a simian malaria parasite, possesses biological and genetic characteristics akin to those of the most widespread human malaria parasite, P. vivax
In total, P. knowlesi was detected in 18 patients, of which 10 cases were newly identified from Ubon Ratchathani Province, which borders Cambodia and Laos
DNA from 10 P. knowlesi isolates from Ubon Ratchathani Province and the 9 P. cynomolgi isolates were subject to nested PCR amplification spanning a 1,318bp region of mitochondrially encoded cytochrome c oxidase I

Summary

Tak Ubon Ratchathani Chanthaburi Yala Narathiwat cases cases

DNA from 10 P. knowlesi isolates from Ubon Ratchathani Province and the 9 P. cynomolgi isolates were subject to nested PCR amplification spanning a 1,318bp region of mitochondrially encoded cytochrome c oxidase I (mtCOX1). Direct sequencing of the purified PCR-amplified template was successfully performed from all 10 P. knowlesi and from 6 P. cynomolgi isolates. The remaining 3 P. cynomolgi isolates could not be further amplified due to inadequate DNA in the samples. All mtCOX1 sequences of P. knowlesi from Ubon Ratchathani Province were different from one another and distinct from those from the previous case of natural human infection in Thailand All 6 amplified P. cynomolgi isolates contained different sequences belonging to 2 clades. All but 1 P. cynomolgi infection occurred in male patients (age 15–53 years, median 32 years). The parasite density of P. cynomolgi could not be determined from blood smears because of morphologic resemblance to P. vivax; an isolate co-infected with P. falciparum (YL3634) had very low parasitemia. Of 8 patients with P. cynomolgi co-infection, 6 had parasitemia

Conclusions

Findings

Monkey in Microscopy