Malaria | Figure 1

Malaria

You can view up to 4 cases without signing up. What is the latest that you have seen malaria present? Have a previously healthy patient with fever, shaking chills, and fatigue for weeks. History of travel to Africa over 6 months ago, used malaria prophylaxis. Physical exam unremarkable other than he appears ill. Lab work shows a worsening hemolytic anemia. Imaging shows hepatosplenomegaly. Peripheral smear pending. Literature I've read says malaria typically becomes symptomatic within a month, but may be delayed with prophylaxis. How delayed are we talking? Six months seems like a very long time.

Update 1

Negative for G6PD deficiency. ID workup negative. Heme/onc workup negative. Spent 2 weeks inpatient and was discharged after anemia improved. No definitive cause was found during his hospital stay.

More about this case

Unresolved

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Clinical Update: Tafenoquine Approved for Malaria Prophylaxis and Treatment.

The US Food and Drug Administration (FDA) has approved the drug tafenoquine for 2 indications:

  1. Prophylaxis of malaria
  2. Radical cure of Plasmodium vivax malaria
    Tafenoquine is an 8-aminoquinoline antimalarial drug related to primaquine. As with primaquine, tafenoquine can cause severe hemolytic anemia in people with G6PD deficiency. Therefore, physicians must perform quantitative G6PD testing before prescribing tafenoquine. Tafenoquine use in people with G6PD deficiency or unknown G6PD status is contraindicated. The long terminal half-life of tafenoquine (approximately 16 days) offers potential advantages in less frequent dosing for prophylaxis and a single-dose course for treatment.

Severe Falciparum Malaria

This child in Sub-Saharan Africa has severe falciparum malaria, presenting with drowsiness, signs of shock, high-grade fever, and splenomegaly. This image shows palmar pallor, a sign of significant anemia. A combination of conjunctival and palmar pallor in children with malaria can indicate the need for transfusion in cases where access to laboratory testing is not available.

Outbreak Report: Wenceslau Guimarães, Bahia State, Brazil

A malaria outbreak has been reported in the town of Wenceslau Guimarães in Bahia State, Brazil. Antimalarial medication is now recommended for travelers to this area. CDC has received reports of an outbreak of P. vivax malaria in Wenceslau Guimarães. The Brazilian Ministry of Health and the public health authorities are continuing to monitor and respond to this outbreak.

Background: Insecticide Resistance

Background
Bed nets treated with pyrethroid insecticides are an effective way to reduce malaria transmission and have been deployed across Africa. However, mosquitoes that spread malaria are now developing resistance to this type of insecticide. One way to overcome this resistance is to add another chemical ‐ piperonyl butoxide (PBO) ‐ to the net. PBO is not an insecticide, but it blocks the substance (an enzyme) inside the mosquito that stops pyrethroids from working.

What is the aim of this review?
The aim of this Cochrane Review was to find out if pyrethroid‐PBO nets provide additional protection against malaria when compared to standard pyrethroid‐only nets.

Key messages
Pyrethroid‐PBO nets were more effective than standard pyrethroid‐only nets in killing mosquitoes and preventing blood feeding in areas where mosquito populations are very resistant to pyrethroid insecticides (high‐certainty evidence). Pyrethroid‐PBO nets reduced the number of malaria infections in areas of high pyrethroid resistance (moderate‐certainty evidence), although further studies are needed to measure clinical outcomes for the full lifetime of the net.

What was studied in the review?
We included 16 trials conducted between 2010 and 2020 that compared standard pyrethroid nets to pyrethroid‐PBO nets. These consisted of 10 experimental hut trials that measured the impact of pyrethroid‐PBO nets on a wild population of mosquitoes, four village trials, and two cRCTs. For both cRCT trials, we examined whether pyrethroid‐PBO nets reduced the number of malaria infections.

What are the main results of the review?
When mosquitoes show high levels of resistance to pyrethroids, pyrethroid‐PBO nets perform better than standard pyrethroid‐only nets for killing mosquitoes and preventing them from blood feeding. Two trials found that fewer people were infected with malaria when the population used pyrethroid‐PBO nets than when standard pyrethroid‐only nets were used.

How up‐to‐date is this review?
We searched for all studies and trials that had been published up to 25 September 2020.