INTRODUCTIONChloroquine, in combination with primaquine, is used as the firstline treatment for uncomplicated P. vivax malaria in Thailand. In view of the declining efficacy of chloroquine in many P. vivax endemic areas, the possibility of emergence of chloroquine- resistant P. vivax in Thailand is a concern. The aim of this study was to assess the trends in therapeutic efficacy of chloroquine and primaquine for the treatment of uncomplicated P. vivax malaria and to assess the utility of parasite clearance times as a measure of efficacy.

MATERIALS AND METHODSThis study consisted of: 1) review of medical records of patients who were hospitalised for a period during their treatment for uncomplicated P. vivax malaria at the Hospital for Tropical Diseases, Bangkok, Thailand between 2004 and 2013. Treatment consisted of chloroquine (1500 mg base administered over 3 days) or chloroquine (as before) plus primaquine (15 to 30 mg base/daily for 14 days from day 2); and 2) systematic review of the literature in English to assess current standards in the reporting of parasite clearance times.

RESULTSThe 28-day cure rate was 99.1%. The range of median parasite clearance time over the 10-year period was 46 to 59 hours, and there was statistical evidence for an increasing trend in parasite clearance times between 2009 and 2013. Heterogeneity was noted among previous chloroquine efficacy studies in the measurement and reporting of parasite clearance.

CONCLUSIONThe treatment of P. vivax infection with a combination of chloroquine and primaquine has remained efficacious in Thailand. Increasing rates of parasite clearance in a population over time may be a useful early warning mechanism for the emergence of chloroquine resistance. The utility of monitoring time-trends in parasite clearance to detect resistance may be enhanced if parasite clearance measurements are standardised.

Antimalarials ; therapeutic use ; Chloroquine ; therapeutic use ; Drug Resistance, Microbial ; Drug Therapy, Combination ; Humans ; Malaria, Vivax ; drug therapy ; Plasmodium vivax ; Primaquine ; therapeutic use ; Thailand ; Time Factors ; Treatment Outcome

No abstract available.
Adult ; Anti-Bacterial Agents/therapeutic use ; Antimalarials/therapeutic use ; Clindamycin/therapeutic use ; Female ; Humans ; Malaria, Vivax/*diagnosis/drug therapy/parasitology ; Neutrophils/*parasitology ; Plasmodium vivax/growth & development/*isolation & purification ; Pregnancy ; Quinine/therapeutic use ; Trophozoites/cytology

Although it is not certain when malaria began to appear in Korea, malaria is believed to have been an endemic disease from ancient times. It was Dr. H. N. Allen (1858-1932) who made the first description and diagnosis of malaria in terms of Western medicine. In his first year report (1885) of Korean Government Hospital he mentioned malaria as the most prevalent disease. Very effective anti-malarial drug quinine was imported and it made great contribution in treating malaria. After Japan had annexed Korea in 1910, policies for public health system were fundamentally revised. Japan assumed control of Korean medical institutions and built high-quality Western hospitals for the health care of Japanese residents. The infectious diseases which were under special surveillance were cholera, typhoid fever, dysentery, typhus, scarlet fever, smallpox, and paratyphoid fever. Among chronic infectious diseases tuberculosis and leprosy were those under special control. Malaria, however, was not one of these specially controlled infectious diseases although it was widely spread throughout the peninsula. But serious studies on malaria were carried out by Japanese medical scientists. In particular, a Japanese parasitologist Kobayasi Harujiro(1884-1969) carried out extensive studies on human parasites, including malaria, in Korea. According to his study, most of the malaria in Korea turned out to be tertian fever. In spite of its high prevalence, malaria did not draw much attention from the colonial authorities and no serious measure was taken since tertian fever is a mild form of malaria caused by Plasmodium vivax and is not so much fatal as tropical malaria caused by P. falciparum. And tertian malaria was easily controlled by taking quinine. Although the majority of malaria in Korea was tertian fever, other types were not absent. Quartan fever was not rarely reported in 1930s. The attitude of colonial authorities toward malaria in Korea was contrasted with that in Taiwan. After Japan had set out to colonize Taiwan as a result of Sino-Japanese war, malaria in Taiwan was a big obstacle to the colonization process. Therefore, a lot of medical scientists were asked to engage the malaria research in order to handle health problems in colonized countries caused by malaria. Unlike the situation in Taiwan, malaria in Korea did not cause a serious health problem as in Taiwan. However, its risk was not negligible. In 1933 there were almost 130,000 malaria patients in Korea and 1,800 patients among them died of malaria. The Japanese Government General took measures to control malaria especially during the 1930s and the number of patients decreased. However, as Japan engaged in the World War II, the general hygienic state of the society worsened and the number of malarial patients increased. The worsened situation remains the same after Liberation (1945) and during the Korean war (1950-53).
Colonialism/history ; History, 19th Century ; History, 20th Century ; Humans ; Korea ; Malaria/diagnosis/drug therapy/*history ; Malaria, Vivax/diagnosis/drug therapy/history ; Microscopy, Polarization ; Plasmodium malariae/isolation & purification ; Plasmodium ovale/isolation & purification ; Plasmodium vivax/isolation & purification ; Quinine/history/therapeutic use

As the last part of a program to survey the extent of malaria transmission in the Papua New Guinea highlands, a series of rapid malaria surveys were conducted in 2003-2004 and 2005 in different parts of Southern Highlands Province. Malaria was found to be highly endemic in Lake Kutubu (prevalence rate (PR): 17-33%), moderate to highly endemic in Erave (PR: 10-31%) and moderately endemic in low-lying parts (< 1500 m) of Poroma and Kagua (PR: 12-17%), but was rare or absent elsewhere. A reported malaria epidemic prior to the 2004 surveys could be confirmed for the Poroma (PR: 26%) but not for the lower Kagua area. In Kutubu/Erave Plasmodium falciparum was the most common cause of infection (42%), followed by P. vivax (39%) and P. malariae (16%). In other areas most infections were due to P. vivax (63%). Most infections were of low density (72% < 500/ microl) and not associated with febrile illness. Overall, malaria was only a significant source of febrile illness when prevalence rates rose above 10%, or in epidemics. However, concurrent parasitaemia led to a significant reduction in haemoglobin (Hb) level (1.2 g/dl, CI95: [1.1-1.4.], p < 0.001) and population mean Hb levels were strongly correlated with overall prevalence of malarial infections (r = -0.79, p < 0.001). Based on the survey results, areas of different malaria epidemiology are delineated and options for control in each area are discussed.
Adolescent ; Adult ; Antimalarials/therapeutic use ; Child ; Child, Preschool ; Endemic Diseases ; *Epidemics ; Female ; Geography, Medical ; Humans ; Malaria/drug therapy/*epidemiology/prevention & control ; Malaria, Falciparum/drug therapy/epidemiology/prevention & control ; Malaria, Vivax/drug therapy/epidemiology/prevention & control ; Male ; Mosquito Nets/utilization ; Papua New Guinea/epidemiology ; Prevalence ; Young Adult

Malarial infection is one of the most important tropical diseases, but also increasing in the temperate regions. Severe malaria with organ dysfunction is commonly associated with Plasmodium falciparum, but rarely with Plasmodium vivax. Malarial hepatitis is also unusual in P. falciparum and very rare in P. vivax. Only 3 cases of malarial hepatitis caused by P. vivax have been reported in the world. Because the presence of hepatitis in malaria indicates a more severe illness with higher incidence of other complications and poor prognosis, malarial patients should be meticulously monitored for hepatic dysfunction with or without jaundice. We report here a case of malarial hepatitis caused by P. vivax that was presented by fever, general ache, nausea, fatigue, and significant elevation of aminotransferase and bilirubin.
Abdomen/ultrasonography ; Antimalarials/therapeutic use ; Erythrocytes/immunology/parasitology ; Fatigue/etiology ; Hepatitis/*diagnosis/etiology/ultrasonography ; Humans ; Malaria, Vivax/complications/*diagnosis/drug therapy ; Male ; Mefloquine/therapeutic use ; Nausea/etiology ; Plasmodium vivax/isolation & purification ; Primaquine/therapeutic use ; Young Adult

The annual incidence of Plasmodium vivax malaria that reemerged in the Republic of Korea (ROK) in 1993 increased annually, reaching 4,142 cases in 2000, decreased to 864 cases in 2004, and once again increased to reach more than 2,000 cases by 2007. Early after reemergence, more than two-thirds of the total annual cases were reported among military personnel. However, subsequently, the proportion of civilian cases increased consistently, reaching over 60% in 2006. P. vivax malaria has mainly occurred in the areas adjacent to the Demilitarized Zone, which strongly suggests that malaria situation in ROK has been directly influenced by infected mosquitoes originating from the Democratic People's Republic of Korea (DPRK). Besides the direct influence from DPRK, local transmission within ROK was also likely. P. vivax malaria in ROK exhibited a typical unstable pattern with a unimodal peak from June through September. Chemoprophylaxis with hydroxychloroquine (HCQ) and primaquine, which was expanded from approximately 16,000 soldiers in 1997 to 200,000 soldiers in 2005, contributed to the reduction in number of cases among military personnel. However, the efficacy of the mass chemoprophylaxis has been hampered by poor compliance. Since 2000, many prophylactic failure cases due to resistance to the HCQ prophylactic regimen have been reported and 2 cases of chloroquine (CQ)-resistant P. vivax were reported, representing the first-known cases of CQ-resistant P. vivax from a temperate region of Asia. Continuous surveillance and monitoring are warranted to prevent further expansion of CQ-resistant P. vivax in ROK.
Antimalarials/administration & dosage ; Chemoprevention ; *Disease Outbreaks ; Drug Resistance ; Humans ; Malaria, Vivax/drug therapy/*epidemiology/parasitology/prevention & control ; Military Personnel ; Plasmodium vivax/drug effects/*physiology ; Republic of Korea/epidemiology

Chloroquine remains the drug of choice for the treatment of vivax malaria in Thailand. Mixed infections of falciparum and vivax malaria are also common in South-East Asia. Laboratory confirmation of malaria species is not generally available. This study aimed to find alternative regimens for treating both malaria species by using falciparum antimalarial drugs. From June 2004 to May 2005, 98 patients with Plasmodium vivax were randomly treated with either artemether-lumefantrine (n = 47) or chloroquine (n = 51). Both treatments were followed by 15 mg of primaquine over 14 days. Adverse events and clinical and parasitological outcomes were recorded and revealed similar in both groups. The cure rate was 97.4% for the artemether-lumefantrine treated group and 100% for the chloroquine treated group. We concluded that the combination of artemether-lumefantrine and primaquine was well tolerated, as effective as chloroquine and primaquine, and can be an alternative regimen for treatment of vivax malaria especially in the event that a mixed infection of falciparum and vivax malaria could not be ruled out.
Adolescent ; Aged ; Animals ; Antimalarials/adverse effects/*therapeutic use ; Artemisinins/adverse effects/*therapeutic use ; Chloroquine/adverse effects/*therapeutic use ; Drug Therapy, Combination ; Ethanolamines/adverse effects/*therapeutic use ; Female ; Fluorenes/adverse effects/*therapeutic use ; Humans ; Malaria, Vivax/*drug therapy ; Male ; Middle Aged ; Parasitemia ; Plasmodium vivax/drug effects ; Primaquine/therapeutic use ; Thailand ; Treatment Outcome

Splenic infarction is a rare complication in malaria cases, and is caused primarily by Plasmodium falciparum. Recently in South Korea, only P. vivax has prevailed since 1993. Although the probability that symptomatic splenic infarction may occur in vivax malaria cases is considered relatively high, there have never been any case reports describing the occurrence of symptomatic splenic infarction in cases of vivax malaria. A 34-year-old man presented with fever that had persisted for 5 days. P. vivax infection was verified using a peripheral blood smear, and chloroquine was utilized to treat the fever successfully. Six days later, the patient developed pain in the left upper abdomen, which was diagnosed as splenic infarction by computed tomography.
Adult ; Animals ; Humans ; Malaria, Vivax/blood/*complications/drug therapy ; Male ; Plasmodium vivax/*isolation & purification ; Primaquine/therapeutic use ; Splenic Infarction/blood/*parasitology

Splenic infarction is a rare complication in malaria cases, and is caused primarily by Plasmodium falciparum. Recently in South Korea, only P. vivax has prevailed since 1993. Although the probability that symptomatic splenic infarction may occur in vivax malaria cases is considered relatively high, there have never been any case reports describing the occurrence of symptomatic splenic infarction in cases of vivax malaria. A 34-year-old man presented with fever that had persisted for 5 days. P. vivax infection was verified using a peripheral blood smear, and chloroquine was utilized to treat the fever successfully. Six days later, the patient developed pain in the left upper abdomen, which was diagnosed as splenic infarction by computed tomography.
Adult ; Animals ; Humans ; Malaria, Vivax/blood/*complications/drug therapy ; Male ; Plasmodium vivax/*isolation & purification ; Primaquine/therapeutic use ; Splenic Infarction/blood/*parasitology

We conducted a study to compare the safety and tolerability of anti-relapse drugs elubaquine and primaquine against Plasmodium vivax malaria. After standard therapy with chloroquine, 30 mg/kg given over 3 days, 141 patients with P. vivax infection were randomized to receive primaquine or elubaquine. The 2 treatment regimens were primaquine 30 mg once daily for 7 days (group A, n = 71), and elubaquine 25 mg once daily for 7 days (group B, n = 70). All patients cleared parasitemia within 7 days after chloroquine treatment. Among patients treated with primaquine, one patient relapsed on day 26; no relapse occurred with elubaquine treatement. Both drugs were well tolerated. Adverse effects occurred only in patients with G6PD deficiency who were treated with primaquine (group A, n = 4), whose mean hematocrit fell significantly on days 7, 8 and 9 (P = 0.015, 0.027, and 0.048, respectively). No significant change in hematocrit was observed in patients with G6PD deficiency who were treated with elubaquine (group B, n = 3) or in patients with normal G6PD. In conclusion, elubaquine, as anti-relapse therapy for P. vivax malaria, was as safe and well tolerated as primaquine and did not cause clinically significant hemolysis.
Thailand ; Prospective Studies ; Primaquine/adverse effects/*analogs & derivatives/therapeutic use ; *Plasmodium vivax ; Middle Aged ; Male ; Malaria, Vivax/*drug therapy ; Humans ; Female ; Chloroquine/therapeutic use ; Antimalarials/*adverse effects/therapeutic use ; Animals ; Adult ; Adolescent