Many specialists in tropical medicine consider that patients with imported malaria, at least those with Plasmodium falciparum malaria, should be admitted to hospital, as complications can develop quickly.1 In Switzerland, patients with malaria who lack signs of severe disease are treated as outpatients, because empirical observations of patients with imported malaria show that death is usually due to a delay in diagnosis rather than complications during treatment.2 We conducted a prospective study in the outpatient clinic of a university hospital to assess the safety of treating imported malaria in an ambulatory setting.
Participants, methods, and results
We conducted our study from January 1990 to July 2000. At study entry we used predefined clinical and laboratory criteria (table) to determine if patients with malaria required admission to hospital. If no criteria were met, ambulatory treatment was considered appropriate. Patients received the first dose of drugs under supervision and were kept under surveillance for one hour before being sent home with instructions. Follow up was at the attending doctor's discretion: clinical and parasitological assessments were performed daily until symptoms resolved and one blood slide was clear of parasites.
Overall, 165 (17%) of 958 patients with fever were positive for parasites; 113 (69%) had P falciparum. Seventy one (43%) of the 165 were first generation immigrants and none was white; and 135 (82%) had travelled to Africa. Median age was 33.7 (range 16-76) years, and median time from onset of symptoms to consultation was four days. Seventy seven (47%) patients had a parasitaemia of 0.1% or less and 10 (6%) of 2% or more.
We admitted 36 (22%) patients immediately; 33 had at least one of the predefined criteria for admission (23 had more than one), and 31 had P falciparum. Seven patients met one criterion but were not admitted, six because the doctor did not comply with the recommendations; one patient refused (this patient had a parasitaemia of 4.5% and recovered uneventfully).
We followed up 129 (78%) patients as outpatients (82 with P falciparum); 88 (68%) were treated with mefloquine alone or in combination with sulfadoxine and pyrimethamine. Six of the 129 patients were admitted during treatment. Two patients with P falciparum returned before the scheduled follow up because of dizziness, probably related to an adverse drug event. Two patients with P falciparum were observed for 40 and 60 hours, respectively, because their fever had persisted. One patient with P ovale was admitted after 24 hours because of a change in general condition and vomiting. None of these five patients received second line antimalarial treatment. The sixth patient was admitted after 48 hours with slight cough and difficulty breathing and needed assisted ventilation three days after admission. All patients recovered uneventfully.
Comment
Ambulatory management of imported malaria seems to be safe, provided that criteria for severity are considered. Previous studies on imported malaria were conducted in specialised tropical centres, where patients tend to present late with disease and thus have a high risk of complications.3 Our study was conducted prospectively in a setting comparable to primary care. Only 5% of patients were admitted during treatment, and none died. The inclusion of 43% of migrants with some immunity did not bias towards a favourable outcome because their clinical presentation and rate of primary admission were similar to those found for naive travellers.3
Our sample size may not have had enough power to detect a small increase in case fatality rate. However, outpatient management of uncomplicated malaria is standard care in Switzerland, and a review of all reported deaths25 in the past 10 years showed that none could be attributed to the acceleration of malaria that had been judged sufficiently mild to be treated outside hospital.
Conditions favouring a good outcome in our setting included a clinic that was open all hours, specialist supervision, and easy accessibility because of short distances to travel. Mefloquine is not standard treatment internationally, although alternative drugs such as atovaquone with proguanil or artemether with lumefantrine may help to manage uncomplicated malaria in an ambulatory setting.4
Table.
Predefined clinical and laboratory criteria for admission of patients with malaria to hospital and number of patients primarily admitted to hospital with the condition
| Criteria | No (%) of patients (n=36) |
|---|---|
| Clinical | |
| Poor general condition | 23 (64) |
| Repeated vomiting | 9 (25) |
| Temperature >40°C | 9 (25) |
| Hypotension | 4 (11) |
| Any neurological problem | 5 (14) |
| Any respiratory problem | 0 |
| Any bleeding sign | 0 |
| Jaundice | 5 (14) |
| Failure with previous antimalarial treatment | 0 |
| Poor compliance | 0 |
| Alone at home | 0 |
| Pregnancy | 0 |
| Laboratory | |
| Parasitaemia >2% | 8 (22) |
| Platelets <20 g/l | 6 (17) |
| Haemoglobin <80 g/dl | 0 |
| Creatinine >250 μmol/ml | 0 |
| Glycaemia <3.9 mmol/l | 0 |
Footnotes
Funding: None.
Competing interests: None declared.
References
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