Assessing the severity of malaria

UK malaria treatment guidelines 2016

1.Malaria is the tropical disease most commonly imported into the UK, with 1300-1800 cases reported each year, and 2-11 deaths. 2. Approximately three quarters of reported malaria cases in the UK are caused by Plasmodium falciparum, which is capable of invading a high proportion of red blood cells and rapidly leading to severe or life-threatening multi-organ disease. 3. Most non-falciparum malaria cases are caused by Plasmodium vivax; a few cases are caused by the other species of plasmodium: Plasmodium ovale, Plasmodium malariae or Plasmodium knowlesi. 4. Mixed infections with more than one species of parasite can occur; they commonly involve P. falciparum with the attendant risks of severe malaria. 5. There are no typical clinical features of malaria; even fever is not invariably present. Malaria in children (and sometimes in adults) may present with misleading symptoms such as gastrointestinal features, sore throat or lower respiratory complaints. 6. A diagnosis of malaria must always be sought in a feverish or sick child or adult who has visited malaria-endemic areas. Specific country information on malaria can be found at http://travelhealthpro.org.uk/. P. falciparum infection rarely presents more than six months after exposure but presentation of other species can occur more than a year after exposure. 7. Management of malaria depends on awareness of the diagnosis and on performing the correct diagnostic tests: the diagnosis cannot be excluded until more than one blood specimen has been examined. Other travel related infections, especially viral haemorrhagic fevers, should also be considered. 8. The optimum diagnostic procedure is examination of thick and thin blood films by an expert to detect and speciate the malarial parasites. P. falciparum and P. vivax (depending upon the product) malaria can be diagnosed almost as accurately using rapid diagnostic tests (RDTs) which detect plasmodial antigens. RDTs for other Plasmodium species are not as reliable. 9. Most patients treated for P. falciparum malaria should be admitted to hospital for at least 24 h as patients can deteriorate suddenly, especially early in the course of treatment. In specialised units seeing large numbers of patients, outpatient treatment may be considered if specific protocols for patient selection and follow up are in place. 10. Uncomplicated P. falciparum malaria should be treated with an artemisinin combination therapy (Grade 1A). Artemether-lumefantrine (Riamet(®)) is the drug of choice (Grade 2C) and dihydroartemisinin-piperaquine (Eurartesim(®)) is an alternative. Quinine or atovaquone-proguanil (Malarone(®)) can be used if an ACT is not available. Quinine is highly effective but poorly-tolerated in prolonged treatment and should be used in combination with an additional drug, usually oral doxycycline. 11. Severe falciparum malaria, or infections complicated by a relatively high parasite count (more than 2% of red blood cells parasitized) should be treated with intravenous therapy until the patient is well enough to continue with oral treatment. Severe malaria is a rare complication of P. vivax or P. knowlesi infection and also requires parenteral therapy. 12. The treatment of choice for severe or complicated malaria in adults and children is intravenous artesunate (Grade 1A). Intravenous artesunate is unlicensed in the EU but is available in many centres. The alternative is intravenous quinine, which should be started immediately if artesunate is not available (Grade 1A). Patients treated with intravenous quinine require careful monitoring for hypoglycemia. 13. Patients with severe or complicated malaria should be managed in a high-dependency or intensive care environment. They may require haemodynamic support and management of: acute respiratory distress syndrome, disseminated intravascular coagulation, acute kidney injury, seizures, and severe intercurrent infections including Gram-negative bacteraemia/septicaemia. 14. Children with severe malaria should also be treated with empirical broad spectrum antibiotics until bacterial infection can be excluded (Grade 1B). 15. Haemolysis occurs in approximately 10-15% patients following intravenous artesunate treatment. Haemoglobin concentrations should be checked approximately 14 days following treatment in those treated with IV artemisinins (Grade 2C). 16. Falciparum malaria in pregnancy is more likely to be complicated: the placenta contains high levels of parasites, stillbirth or early delivery may occur and diagnosis can be difficult if parasites are concentrated in the placenta and scanty in the blood. 17. Uncomplicated falciparum malaria in the second and third trimester of pregnancy should be treated with artemether-lumefantrine (Grade 2B). Uncomplicated falciparum malaria in the first trimester of pregnancy should usually be treated with quinine and clindamycin but specialist advice should be sought. Severe malaria in any trimester of pregnancy should be treated as for any other patient with artesunate preferred over quinine (Grade 1C). 18. Children with uncomplicated malaria should be treated with an ACT (artemether-lumefantrine or dihydroartemisinin-piperaquine) as first line treatment (Grade 1A). Quinine with doxycycline or clindamycin, or atovaquone-proguanil at appropriate doses for weight can also be used. Doxycycline should not be given to children under 12 years. 19. Either an oral ACT or chloroquine can be used for the treatment of non-falciparum malaria. An oral ACT is preferred for a mixed infection, if there is uncertainty about the infecting species, or for P. vivax infection from areas where chloroquine resistance is common (Grade 1B). 20. Dormant parasites (hypnozoites) persist in the liver after treatment of P. vivax or P. ovale infection: the only currently effective drug for eradication of hypnozoites is primaquine (1A). Primaquine is more effective at preventing relapse if taken at the same time as chloroquine (Grade 1C). 21. Primaquine should be avoided or given with caution under expert supervision in patients with Glucose-6-phosphate dehydrogenase deficiency (G6PD), in whom it may cause severe haemolysis. 22. Primaquine (for eradication of P. vivax or P. ovale hypnozoites) is contraindicated in pregnancy and when breastfeeding (until the G6PD status of child is known); after initial treatment for these infections a pregnant woman should take weekly chloroquine prophylaxis until after delivery or cessation of breastfeeding when hypnozoite eradication can be considered. 23. An acute attack of malaria does not confer protection from future attacks: individuals who have had malaria should take effective anti-mosquito precautions and chemoprophylaxis during future visits to endemic areas.

Severe falciparum malaria in iran: a very rare case from an endemic region

Introduction:

Malaria is a protozoal disease, transmitted to humans by female Anopheles mosquito bite. Plasmodium falciparum, compared to other kinds of Plasmodium, causes more severe malaria and is associated with a higher mortality rate. Annually, one to three million deaths occur due to malaria, especially by P. falciparum.

Case Presentation:

In this report, we introduce an Iranian patient suffering from P. falciparum. Peripheral blood smear for malaria parasites showed severe infection of P. falciparum, with 75 to 85 percent of red blood cells containing one to five parasites per cell. However, the patient revealed a fast response to treatment and a good prognosis, suggesting a high level of relative immunity in the patient. To confirm this hypothesis, we conducted a comparative study by comparing the rate of clinical response to treatment as well as the level of prognosis of our patient with similar patients from different regions around the world. These included some malaria cases (caused by P. falciparum) chosen from endemic and nonendemic regions, such as Africa, South Europe and Canada.

Discussion:

The findings revealed that generally, patients from endemic regions significantly show a greater response to treatment and also a better prognosis in comparison to the patients from nonendemic regions. These differences can plausibly be attributed to a high level of relative immunity in endemic regions. Consequently, we would strongly support the hypothesis that response to treatment and prognosis of malaria is a matter of patients’ living environment circumstances. In other words, people who live in endemic regions acquire a high relative immunity leading to a greater response to treatment and a better prognosis.

Malaria: an update for physicians

Malaria remains the most important parasitic infection in humans. There have been significant advances in the treatment of both nonsevere and severe malaria with the advent of artemisinin combination therapies and parenteral artesunate, but the optimum supportive management of severe malaria is unclear. A broadly acceptable therapy for the prevention of relapses in Plasmodium vivax infection has not been discovered. Globally, the priority remains to prevent infection in the vulnerable, to move toward elimination where feasible, and to ensure that effective treatment is available to all. In developed settings, prevention of infection and its early recognition are crucial.

Critical care aspects of malaria

Malaria remains a major health problem in much of Asia and Africa. A steady number of cases of imported malaria are also seen in many countries of the developed world. Plasmodium falciparum malaria and to some extent malaria caused by other species of Plasmodium can lead to many complications such as acute respiratory distress syndrome (ARDS), cerebral malaria, acute renal failure, severe anemia, thrombocytopenia, and bleeding complications. About 10% of patients with severe malaria die, usually as a result of multiorgan dysfunction. Critical care physicians should be aware of the complications and management of severe malaria. There has been significant progress in the understanding of pathogenesis of severe malaria over the last decade. Effective management of severe malaria includes early suspicion, prompt diagnosis, early institution of appropriate antimalarial chemotherapy, and supportive care, preferably in an intensive care unit. In this article, we review the different manifestations of severe malaria as relevant to critical care physicians and discuss the principles of laboratory diagnosis and management.

Selective ambulatory management of Plasmodium falciparum malaria in paediatric refugees

BACKGROUND

Plasmodium falciparum (Pf) malaria is a leading cause of childhood mortality and morbidity. In developed countries, it is widely recommended that even patients with uncomplicated Pf malaria are hospitalised for at least 24 h, whereas ambulatory treatment is usual for uncomplicated infections in developing countries. This observational study assessed the safety of selective admission of paediatric refugees with Pf malaria in Australia.

METHODS

Data were collected on African humanitarian refugee children (<16 years of age) presenting with malaria between February 2005 and April 2006. Children were treated as outpatients if they fulfilled specific criteria devised to maximise the safety of outpatient management of this potentially life-threatening condition.

RESULTS

Ninety paediatric refugees were infected with P falciparum, of whom 56 were treated as outpatients. Of the 34 children admitted to hospital, four had parasite loads > or =4%. Most children were treated with oral atovaquone-proguanil. Eighty eight patients attended follow-up; all were compliant and none reported side-effects. One infant failed treatment and was subsequently readmitted; he did not meet criteria for severe malaria on either occasion and had been initially treated as an inpatient.

CONCLUSIONS

Using this protocol, outpatient management of refugee children with Pf malaria appears safe, with minimal complication and treatment failure rates. This approach has rationalised management of paediatric malaria in this carefully selected population and substantially reduced utilisation of hospital resources.

Laboratory indicators of the diagnosis and course of imported malaria

When travellers return from malaria-endemic areas and present to hospital with fever, microscopy of blood smears remains the leading method to verify a suspected diagnosis of malaria. Additional laboratory abnormalities may, however, also be indicative of acute malaria infection. We monitored prospectively a group of patients with imported Plasmodium falciparum (n=28) or P. vivax/P. ovale (n=12) infection, respectively, and assessed haemoglobin, leucocytes, thrombocytes, C-reactive protein, coagulation factor II-VII-X, lactate dehydrogenase and bilirubin during 7 d of admission and weekly until d 28. For comparison, admission values of a group of febrile patients with suspected malaria, but with negative blood slides, were also assessed (n=66). The thrombocyte, leucocyte counts and coagulation factor II-VII-X were significantly lower in the malaria group compared to the non-malaria group, whereas the C-reactive protein, lactate dehydrogenase and bilirubin were significantly higher in the malaria group. The differences were particularly strong with falciparum malaria. By contrast, haemoglobin levels were not affected. In conclusion, our study emphasizes the role of a few commonly analysed laboratory parameters, in particular thrombocyte counts, in guiding the clinician managing a returning traveller with fever.

Selective ambulatory management of imported falciparum malaria: a 5-year prospective study

The ambulatory management of imported Plasmodium falciparum malaria is controversial because criteria for safe selection of patients are imprecise. The aim of the present study was to investigate the evolution and outcome of patients diagnosed with Plasmodium falciparum malaria at a Belgian referral institute in order to assess the safety of the institute's current selective ambulatory management protocol. From 2000 to 2005, all patients diagnosed with P. falciparum infection at the Institute of Tropical Medicine and the University Hospital of Antwerp were enrolled prospectively. Ambulatory treatment was offered to nonvomiting patients if they exhibited none of the 2000 World Health Organization criteria of severity and had parasitemia below 1% at the initial assessment. The treatment of choice was quinine (plus doxycycline or clindamycin) for inpatients and atovaquone-proguanil for outpatients. P. falciparum malaria was diagnosed in 387 patients, of whom 246 (64%) were Western travelers or expatriates and 117 (30%) were already on antimalarial therapy. At diagnosis, 60 (15%) patients had severe malaria. Vital organ dysfunction was initially seen in 34 and developed later in five others. Five patients died. Of the 327 patients initially assessed as having uncomplicated malaria, 113 (35%) were admitted immediately; of these, 4 developed parasitemia >/=5% at a later stage but without any clinical consequence. None of the 214 individuals initially treated as outpatients experienced any malaria-related complications, including 10 who were admitted later. Vital organ dysfunction was observed in only 2 of the 214 patients with initial parasitemia <1% who had not taken antimalarial agents (both patients had impaired consciousness at presentation). Ambulatory treatment is safe in treatment-naive malaria patients with parasitemia <1% who do not vomit and who do not exhibit any criteria of severe malaria.

UK malaria treatment guidelines

Malaria is the tropical disease most commonly imported into the UK, with 1500-2000 cases reported each year, and 10-20 deaths. Approximately three-quarters of reported malaria cases in the UK are caused by Plasmodium falciparum, which is capable of invading a high proportion of red blood cells and rapidly leading to severe or life-threatening multi-organ disease. Most non-falciparum malaria cases are caused by Plasmodium vivax; a few cases are caused by the other two species of Plasmodium: Plasmodium ovale or Plasmodium malariae. Mixed infections with more than 1 species of parasite can occur; they commonly involve P. falciparum with the attendant risks of severe malaria. Management of malaria depends on awareness of the diagnosis and on performing the correct diagnostic tests: the diagnosis cannot be excluded until 3 blood specimens have been examined by an experienced microscopist. There are no typical clinical features of malaria, even fever is not invariably present. The optimum diagnostic procedure is examination of thick and thin blood films by an expert to detect and speciate the malarial parasites; P. falciparum malaria can be diagnosed almost as accurately using rapid diagnostic tests (RDTs) which detect plasmodial antigens or enzymes, although RDTs for other Plasmodium species are not as reliable. The treatment of choice for non-falciparum malaria is a 3-day course of oral chloroquine, to which only a limited proportion of P. vivax strains have gained resistance. Dormant parasites (hypnozoites) persist in the liver after treatment of P. vivax or P. ovale infection: the only currently effective drug for eradication of hypnozoites is primaquine. This must be avoided or given with caution under expert supervision in patients with glucose-6-phosphate dehydrogenase deficiency (G6PD), in whom it may cause severe haemolysis. Uncomplicated P. falciparum malaria can be treated orally with quinine, atovaquone plus proguanil (Malarone) or co-artemether (Riamet); quinine is highly effective but poorly tolerated in prolonged dosage and is always supplemented by additional treatment, usually with oral doxycycline. ALL patients treated for P. falciparum malaria should be admitted to hospital for at least 24 h, since patients can deteriorate suddenly, especially early in the course of treatment. Severe falciparum malaria, or infections complicated by a relatively high parasite count (more than 2% of red blood cells parasitized), should be treated with intravenous therapy until the patient is well enough to continue with oral treatment. In the UK, the treatment of choice for severe or complicated malaria is currently an infusion of intravenous quinine. This may exacerbate hypoglycaemia that can occur in malaria; patients treated with intravenous quinine therefore require careful monitoring. Intravenous artesunate reduces high parasite loads more rapidly than quinine and is more effective in treating severe malaria in selected situations. It can also be used in patients with contra-indications to quinine. Intravenous artesunate is unlicensed in the EU. Assistance in obtaining artesunate may be sought from specialist tropical medicine centres, on consultation, for named patients. Patients with severe or complicated malaria should be managed in a high dependency or intensive care environment. They may require haemodynamic support and management of acute respiratory distress syndrome, disseminated intravascular coagulation, renal impairment/failure, seizures, and severe intercurrent infections including gram-negative bacteraemia/septicaemia. Falciparum malaria in pregnancy is more likely to be severe and complicated: the placenta contains high levels of parasites. Stillbirth or early delivery may occur and diagnosis can be difficult if parasites are concentrated in the placenta and scanty in the blood. The treatment of choice for falciparum malaria in pregnancy is quinine; doxycycline is contraindicated in pregnancy but clindamycin can be substituted for it, and is equally effective. Primaquine (for eradication of P. vivax or P. ovale hypnozoites) is contraindicated in pregnancy; after treatment for these infections a pregnant woman should take weekly chloroquine prophylaxis until after delivery when hypnozoite eradication can be considered. Children are over-represented in the incidence of malaria in the UK, probably because completely susceptible UK-born children accompany their overseas-born parents on visits to family and friends in endemic areas. Malaria in children (and sometimes in adults) may present with misleading symptoms such as gastrointestinal features, sore throat or lower respiratory complaints; the diagnosis must always be sought in a feverish or very sick child who has visited malaria-endemic areas. Children can be treated with most of the antimalarial regimens which are effective in adults, with appropriate dosage adjustment. Doxycycline plus quinine should not be given to children under 12 years as doxycycline is contraindicated in this age group, but clindamycin can be substituted for doxycycline, and pyrimethamine-sulfadoxine (Fansidar) may also be an effective substitute. An acute attack of malaria does not confer protection from future attacks: individuals who have had malaria should take effective anti-mosquito precautions and chemoprophylaxis during future visits to endemic areas.

[Malaria]

Imported malaria is an important problem in non-endemic areas because of increasing numbers of travelers, overseas workers and immigrants. Since the presentation of malaria is vague and nonspecific, the diagnosis should be considered in any appropriately symptomatic patient with a history of travel to a malaria-endemic area. If the diagnosis is not made in about one day, the disease can have a fatal outcome. Microscopy of thick and thin blood smears remains the standard laboratory method, although also polymerase chain reaction has become an important diagnostic and research technique in malaria. The main classes of drugs used are the quinoline-related compounds (chloroquine, mefloquine, primaquine), atovaquon/proguanil and the artemisinin derivatives. Management of severe and complicated malaria requires special attention: patients have to be admitted to an intensive care unit, supportive measures must be initiated, and parenteral treatment with quinine should be started as quickly as possible.

Paediatric malaria: What do paediatricians need to know?

Although malaria is principally a disease of the tropical and subtropical regions of the world, it is an important disease to be familiar with for both local and global reasons. It remains to be one of the most important infectious diseases of the world, particularly in sub-Saharan Africa, killing more than one million people - mostly children - every year. In Canada, at least 350 to 1100 imported cases are reported annually, 25% of which are in the paediatric age group, as a result of both travel and migration. Because malaria is a potentially severe and sometimes fatal disease that is unfamiliar to many paediatricians in Canada, it is important that clinicians become familiar with its clinical presentation; understand when it should be suspected; and have an approach to prompt diagnosis, appropriate treatment and effective prevention methods.

Evaluation of plasma lactate as a parameter for disease severity on admission in travelers with Plasmodium falciparum malaria

BACKGROUND

Rapid immunochromatographic dipstick assays are used increasingly in many tropical and Western countries as a tool to diagnose Plasmodium falciparum malaria. However, these tests do not provide any information about the severity of the infection. We evaluated the usefulness of plasma lactate as a parameter for disease severity on admission in imported P. falciparum malaria.

METHODS

In a cohort of 61 nonimmune travelers with imported P. falciparum malaria, plasma lactate levels on admission were related to the severity of the infection. Results from 12 of 61 patients fulfilled the criteria of severe malaria.

RESULTS

Logistic regression analysis showed that a plasma lactate level above the upper range of normal was associated with an odds ratio of 31 (95% CI 6-164) for severe malaria. As a continuous variable, a 1 mmol/L increase in plasma lactate level was associated with an odds ratio of 12 (95% CI 3-50) for severe malaria. The sensitivity of an increased plasma lactate level on admission for severe malaria was 67% with a specificity of 94%.

CONCLUSIONS

A timely determination of plasma lactate on admission may be helpful in the assessment of disease severity in travelers with imported P. falciparum malaria. An increased plasma lactate level should raise suspicion of a severe P. falciparum malaria infection, in particular when concomitant infections are not considered likely.

Management of severe malaria: interventions and controversies

This article emphasizes that for many controversial reasons, severe malaria in travelers differs from that seen in endemic areas. There is no controversy, however, that malaria in individuals living in endemic areas should retain research priority. Some of the questions raised might never be amenable to randomized controlled trials, either because of ethical or logistical restraints. A possibly indulgent wish list of outcome (mortality) studies using currently known treatment modalities, however, includes the loading dose of quinine, vigorous fluid replacement, ET, the artemisinins, mannitol, and N-acetylcysteine in the treatment of severe malaria. There may clearly be many more. The treatment of severe malaria remains a challenge to those with an interest in managing life-threatening disease with complex and fascinating pathophysiology. As challenging as the studies listed previously may seem, however, priority must inevitably be given to research on how one can prevent and treat mild disease in the first place.