Clinical features of vivax malaria

Case reports: pernicious complications of benign tertian malaria

We describe 2 patients with complications of Plasmodium vivax malaria. Both patients developed marked intravascular haemolysis and haemoglobinuria despite normal levels of glucose-6-phosphate dehydrogenase activity in blood. One required mechanical ventilation because of life-threatening hypoxia due to acute respiratory distress syndrome.

Retinal haemorrhage in vivax malaria

Retinal haemorrhage is often observed in patients with Plasmodium falciparum, especially when combined with cerebral malaria. However, few cases of retinopathy have been reported in P. vivax malaria. Benign tertian malaria has re-emerged among soldiers in the South Korean demilitarized zone since 1993. We report an indigenous case of retinal haemorrhage caused by P. vivax and review the relevant literature.

Idiopathic thrombocytopenic purpura due to vivax malaria in the Brazilian Amazon

We describe a rare case of idiopathic thrombocytopenic purpura (ITP) triggered by Plasmodium vivax infection. The patient developed thrombocytopenia and bleeding associated with three episodes of malaria, and became dependent on corticosteroid therapy. The mechanisms by which this parasite evokes thrombocytopenia remain obscure.

Clinical features of Plasmodium vivax malaria

BACKGROUND

Since its reemergence in 1993, a number of cases of Plasmodium vivax malaria have been reported in Korea. We analyzed the cases of malaria patients living in Chuncheon and its neighboring communities, to characterize its clinical manifestations and laboratory findings, and to identify any differences between our clinical findings and those of previous studies.

METHODS

We reviewed the clinical records of cases that were confirmed as malaria by peripheral blood smear at Chuncheon Sacred Heart Hospital from July 1998 to September 2001.

RESULTS

Forty-four cases were included in the study. All patients were infected with Plasmodium vivax, and presented with high fever; however, tertian fever developed in only 15 patients (35.7%). A number of cases showed various symptoms, which included headache, abdominal pain, nausea and vomiting. Of the 44 cases identified, 41 (93.2%) developed malaria between June and September. Thrombocytopenia was a prominent finding in 75% of the cases at diagnosis, but resolved during or after therapy. Other laboratory abnormalities such as, anemia, elevated transamines, coagulopathies, and elevated lactose dehydrogenase (LDH) were also noted. Cerebrospinal fluid (CSF) studies were performed in five cases, one of which showed pleocytosis in the CSF.

CONCLUSION

We noted only 15 patients (35.7%) with tertian fever; the other patients showed variable fever patterns. Thrombocytopenia was the most prominent laboratory finding. Therefore, we suggest that malaria should be included in the differential diagnosis of febrile diseases with an onset between June to and September, regardless of the pattern of the fever.

Serum cytokine profiles in patients with Plasmodium vivax malaria: a comparison between those who presented with and without thrombocytopenia

One of the peculiar features of Plasmodium vivax malaria in South Korea is the surprisingly high frequency of thrombocytopenia. The mechanism by which this malaria-related thrombocytopenia develops and its role in the pathology and progress of human infection with P. vivax have not yet been completely understood. In the present study, the serum cytokine profiles of cases of P. vivax malaria who presented with thrombocytopenia were compared with those of similar cases who did not have thrombocytopenia at presentation. The subjects were the 94 consecutive cases of P. vivax malaria who presented at five hospitals in South Korea (all near the Demilitarized Zone) between May 2000 and October 2002, 47 of whom had thrombocytopenia at presentation. When mean values and (S.E.) were compared, the thrombocytopenic patients were found not only to be generally older than the non-thrombocytopenic [25.3 (1.1) v. 21.3 (0.18) years; P < 0.001] but also to have presented with higher serum concentrations of aspartate aminotransferase [77.6 (16.6) v. 32.3 (7.4) U/litre; P < 0.0001], alanine aminotransferase [96.7 (19.0) v. 44.7 (12.0) U/litre; P = 0.0001], interleukin-1 [49.9 (7.4) v. 23.7 (5.1) pg/ml; P < 0.001], interleukin-6 [174.9 (26.4) v. 57.3 (14.6) pg/ml; P = 0.001], interleukin-10 [308.2 (39.6) v. 137.9 (23.1) pg/ml; P < 0.002] and transforming growth factor-beta [1134.3 (387.5) v. 416.6 (183.8) pg/ml; P < 0.0001], and higher levels of parasitaemia [4345.7 (966.6) v. 1443.8 (222.7) parasites/microl; P = 0.03). The non-thrombocytopenic patients, however, had relatively high total leucocyte counts [5.8 (0.24) v. 5.4 (0.66) leucocytes/nl; P = 0.03]. The thrombocytopenia associated with P. vivax malaria in South Korea therefore appears to be associated with elevated serum concentrations of both pro- and anti-inflammatory cytokines. To define the role of each cytokine in the development of thrombocytopenia during the course of acute P. vivax malaria, further prospective studies are needed.

Assessment of travellers who return home ill

Every year, millions of people travel abroad, exposing themselves to various diseases. Advice on risk avoidance and on self-medication is not always successful; sometimes travellers return home ill or become unwell soon afterwards. There are many possible causes for such illnesses, and physicians should try to establish whether the disease is specifically associated with the recent journey. The approach to assessment of the ill traveller should make use not only of signs and symptoms, but also of geography and epidemiology. Travellers with fever need immediate attention to rule out serious and potentially life-threatening conditions. Faced with a difficult diagnosis, physicians should consult with experts in tropical and travel medicine.