Correction: Yuhana et al. Rickettsial infections are neglected causes of acute febrile illness in Teluk Intan, Peninsular Malaysia. Trop. Med. Infect. Dis. 2022, 7, 77

The authors wish to make the following correction to this paper [...]

The threat of artemisinin resistant malaria in Southeast Asia.

Fifty years ago it was becoming clear that the enormous global effort to eradicate malaria had failed. There were also an increasing number of worrying reports that the wonder drug chloroquine was not working as it should against falciparum malaria in parts of South-East Asia and South America. Chloroquine resistance spread slowly at first, but by 1979 it had reached the Eastern coastline of Africa, and by 1992 it had crossed the entire continent. Chloroquine could no longer be relied upon to treat malaria, and its preventive efficacy was also in decline. Chloroquine was replaced eventually by sulfadoxine-pyrimethamine as first-line treatment, but this fell rapidly to resistance in many places. Later it was shown by analysis of the sequences flanking the mutant resistance genes (Pfcrt and Pfdhfr respectively) that the parasites causing illness and death in Africa had their genetic origins close to the Thailand-Cambodia border [1, 2]. In 1984 mefloquine was introduced as first-line treatment for falciparum malaria in Thailand, but resistance soon followed. The prospect of truly untreatable malaria loomed. The region was saved qinghaosu (artemisinin), a Chinese traditional remedy that has since become the cornerstone of recommended antimalarial treatments [3]. In the treatment of severe malaria parenteral artesunate was shown to reduce mortality substantially and so has become the treatment of choice. Artemisinin-combination therapies (ACTs) are now the first-line treatment for uncomplicated P. falciparum malaria throughout the tropical world, and they are increasingly recommended for vivax malaria [3]. But the history of antimalarial resistance emergence and spread is beginning to repeat itself

The threat of antimalarial drug resistance

The battle between man and malaria has continued for thousands of years. Antimalarial drugs are essential weapons to fight the disease, but their efficacy is threatened by drug resistance which continues to emerge creating a major obstacle to malaria control and jeopardizing renewed hopes for elimination. As 2016 is the first year under WHO Global Technical Strategy for Malaria 2016–2030, it is a good time to ponder the progress of both sides and plan for the future

The threat of antimalarial drug resistance

The battle between man and malaria has continued for thousands of years. Antimalarial drugs are essential weapons to fight the disease, but their efficacy is threatened by drug resistance which continues to emerge creating a major obstacle to malaria control and jeopardizing renewed hopes for elimination. As 2016 is the first year under WHO Global Technical Strategy for Malaria 2016–2030, it is a good time to ponder the progress of both sides and plan for the future

Advances and roadblocks in the treatment of malaria

The deployment of artesunate for severe malaria and the artemisinin combination therapies (ACTs) for uncomplicated malaria has been a major advance in antimalarial therapeutics. These drugs have reduced treated mortality, accelerated recovery and reduced treatment failure rates and transmission from the treated infection. Artemisinin derivatives remain highly effective against falciparum malaria in most malaria endemic areas, but significant resistance has emerged in the Greater Mekong subregion of Southeast Asia. Resistance to artemisinins was followed by resistance to the ACT partner drugs, and fit multidrug resistant parasite lineages have now spread widely across the region. ACTs remain highly effective against P. vivax and the other malaria species. Recent studies have shown that radical curative regimens of primaquine (to prevent relapse) can be shortened to 7 days, and that the newly introduced single dose tafenoquine is an alternative, although the currently recommended dose is insufficient in Southeast Asia and Oceania. Targeted malaria elimination using focal mass treatments with dihydroartemisinin‐piperaquine have proved safe and effective malaria elimination accelerators, but progress overall towards malaria elimination is slow. Indeed since 2015 overall malaria case numbers globally have risen. As new drugs will not become widely available in the near future, active measures to preserve the current antimalarials should be given the highest priority

The threat of artemisinin resistant malaria in Southeast Asia.

Fifty years ago it was becoming clear that the enormous global effort to eradicate malaria had failed. There were also an increasing number of worrying reports that the wonder drug chloroquine was not working as it should against falciparum malaria in parts of South-East Asia and South America. Chloroquine resistance spread slowly at first, but by 1979 it had reached the Eastern coastline of Africa, and by 1992 it had crossed the entire continent. Chloroquine could no longer be relied upon to treat malaria, and its preventive efficacy was also in decline. Chloroquine was replaced eventually by sulfadoxine-pyrimethamine as first-line treatment, but this fell rapidly to resistance in many places. Later it was shown by analysis of the sequences flanking the mutant resistance genes (Pfcrt and Pfdhfr respectively) that the parasites causing illness and death in Africa had their genetic origins close to the Thailand-Cambodia border [1, 2]. In 1984 mefloquine was introduced as first-line treatment for falciparum malaria in Thailand, but resistance soon followed. The prospect of truly untreatable malaria loomed. The region was saved qinghaosu (artemisinin), a Chinese traditional remedy that has since become the cornerstone of recommended antimalarial treatments [3]. In the treatment of severe malaria parenteral artesunate was shown to reduce mortality substantially and so has become the treatment of choice. Artemisinin-combination therapies (ACTs) are now the first-line treatment for uncomplicated P. falciparum malaria throughout the tropical world, and they are increasingly recommended for vivax malaria [3]. But the history of antimalarial resistance emergence and spread is beginning to repeat itself

Rickettsiosis in Southeast Asia: Summary for international travellers during the COVID-19 pandemic

Rickettsiosis is an important cause of febrile illness among travellers visiting Southeast Asia (SEA). The true incidence of rickettsiosis is underestimated; however, murine typhus and scrub typhus are widely distributed across SEA. Among travellers visiting SEA, scrub typhus was mostly reported from Thailand, whereas murine typhus was frequently found in Indonesia. Although most cases are self-limited or present with mild symptoms, a few cases with severe clinical manifestations have been reported. Doxycycline remains the key treatment of rickettsiosis. Some travellers, such as backpackers, trekkers, or cave explorers, are at a higher risk for rickettsiosis than others. Therefore, in resource-limited conditions, empirical treatment should be considered in these travellers. The coronavirus disease 2019 (COVID-19) pandemic has contributed to difficulty in the diagnosis of rickettsiosis because of the clinical similarities between these diseases. In addition, physical distancing mandated by COVID-19 management guidelines limits accurate physical examination, resulting in misdiagnosis and delayed treatment of rickettsiosis. This review summarises the characteristics of murine typhus and scrub typhus, describes travel-associated rickettsiosis, and discusses the impact of the COVID-19 pandemic on rickettsiosi