Introduction

The increase in malaria incidence worldwide is due, in large part, to the development and spread of drug-resistant malaria parasites. Resistance has emerged to virtually all classes of antimalarials, although at very different rates. For the oldest antimalarials [quinine (Q) and artemisinin derivatives], resistance has been slow to develop and treatment failure with these drugs is not an operational problem in most malaria-endemic areas. Until recently, there was no confirmed artemisinin resistance; however, Kyle[1] and Peters[2] recently generated a stable isolate of artemisinin-resistant Plasmodium falciparum malaria. Although resistance to artemisinin has not yet been reported in natural infections, the use of this drug and its derivatives is associated with a high rate of recrudescence after monotherapy; therefore it must be used in combination with longer-lasting antimalarials.1-3-1

For newer synthetic antimalarials, resistance has developed much faster, sometimes at an alarming rate. Chloroquine (CQ) was long considered the prophylactic and therapeutic agent of choice for P. falciparum. Chloroquine-resistant (CQR) falciparum malaria first emerged in Southeast Asia and South America over half a century ago, and subsequently spread to almost all malaria-endemic areas except Central America, above the Panama Canal, Haiti, and parts of China and the Middle East.[4] CQ resistance occurs both in P. falciparum and Plasmodium vivax, but the former accounts for most of the global disease burden. CQR P. vivax malaria is mostly concentrated in Oceania (Papua New Guinea, Vanuatu, and Indonesia) but has also been confirmed in South America.[4-7] As of yet, no confirmed resistance has been documented for Plasmodium malariae or Plasmodium ovale.

The advent of CQ resistance led to the development of other synthetic antimalarials including sulfadoxine pyri-methamine (SP), mefloquine (MQ), halofantrine, and atovaquone (ATQ)-proguanil (MalaroneTM). SP is still used as first-line therapy for treatment of falciparum malaria in much of sub-Saharan Africa and South America, despite evidence for escalating resistance in these regions.[7] MQ is now commonly used in many regions of Southeast Asia, Africa, and South America, and remains an efficacious antimalarial in most endemic regions on the borders of Thailand, with Myanmar and Cambodia where multidrug-resistant falciparum malaria has been the norm since the late 1980s.[4] ATQ-proguanil is the latest antimalarial to be approved for the treatment of falciparum malaria in many western countries. Although presently very efficacious for the treatment of P. falciparum in all endemic regions including areas of multidrug resistance, ATQ-proguanil resistance has now been documented in a limited number of cases, primarily travelers returning from Africa.[8,9]

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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