Methods: The clinical information of the patient was collected. Microscopy of blood smear was conducted after Giemsa staining. Genomic DNA was extracted from blood, and PCR was conducted to amplify rDNA. The PCR products were sequenced and analyzed with BLAST
Results: The patient returned from a one-week tour in a tropical rain forest in Malaysia. The first disease attack occurred in Guangzhou on Oct. 16, 2014, with fever, shivering and sweating. The patient was initially diagnosed as malaria and hospitalized on Oct. 26, 2014. Microscopic observation revealed typical forms of P. knowlesi in blood smear. The red blood cells became enlarged, with big trophozoites appearing as a ring with dual cores and dark brown malaria pigment. The trophozoites were slightly bigger and thicker than P. falciparum. The schizont had 6-8 merozoites, with obvious brown malaria pigment. PCR resulted in a specific band of 1 099 bp. BLAST analysis showed that the sequence of the PCR product was 99% homologous to P. knowlesi (acession No. AM910985.1, L07560.1 and AY580317.1). The patient was diagnosed as P. knowlesi infection, and was then given an 8-day treatment with chloroquine and primaquine, together with dihydroartemisinin piperaquine phosphate tablet. The patient was discharged after recovery on Oct. 28, 2014.
Conclusion: According to the clinical symptoms, epidemiological history and laboratory test, the patient has been confirmed as P. knowlesi infection. It may also be the first active case of knowlesi malaria reported in China.
Materials and Methods: This study was conducted using the livers of 18 mice fixed in 10% neutral-buffered formalin. A completely randomized design with a unidirectional pattern comprising six treatments was used in this study, with each treatment consisting of three replications. Treatment 0 was the negative control group infected with P. berghei, treatment 1 was the positive control group infected with P. berghei followed by chloroquine administration at a dose of 5 mg/kg BW, and treatments 2, 3, 4, and 5 were groups infected with P. berghei and administered Malacca leaf ethanolic extracts at doses of 100, 300, 600, and 1200 mg/kg BW, respectively. The extracts were administered orally using a gastric tube for 4 consecutive days. Mice were sacrificed on the 7th day and livers were collected for histopathological examination.
Results: Histopathological examination of the livers of mice infected with P. berghei demonstrated the presence of hemosiderin, hydropic degeneration, fat degeneration, necrosis, and megalocytosis. However, all these histopathological changes were reduced in the livers of P. berghei-infected mice treated with various doses of Malacca leaf ethanolic extract. The differences between the treatments were found be statistically significant (p<0.05).
Conclusion: Ethanolic extract of Malacca leaves has the potential to protect against liver damage in mice infected with P. berghei. The dose of 600 mg/kg BW was found to be the most effective compared with the doses of 100, 300, and 1200 mg/kg BW.