Lian Huat Tan

Hemophagocytosis in dengue: Comprehensive report of six cases

Hemophagocytic syndrome is a potentially fatal disorder. It is being increasingly reported but remained under-recognized in dengue. Most reported cases were in association with plasma leakage and shock but multi-organ impairment was also observed. We describe the time-lines of 6 cases of confirmed dengue with varying severities of hemophagocytosis. All had persistent fever, cytopenia and elevated transaminases with markedly elevated ferritin levels during and beyond the plasma leakage phase. Acute renal failure and central nervous system manifestation were observed in two patients. Morphological hemophagocytosis was demonstrated in three patients. All survivors showed clinical and biochemical resolution of hemophagocytosis indicating its transient nature. Persistence of fever and cytopenia together with multi-organ dysfunction, out of proportion to and beyond the plasma leakage phase should prompt clinicians to consider this phenomenon.

Acute respiratory distress syndrome and acute renal failure from Plasmodium ovale infection with fatal outcome

BackgroundPlasmodium ovale is one of the causative agents of human malaria. Plasmodium ovale infection has long been thought to be non-fatal. Due to its lower morbidity, P. ovale receives little attention in malaria research.MethodsTwo Malaysians went to Nigeria for two weeks. After returning to Malaysia, they fell sick and were admitted to different hospitals. Plasmodium ovale parasites were identified from blood smears of these patients. The species identification was further confirmed with nested PCR. One of them was successfully treated with no incident of relapse within 12-month medical follow-up. The other patient came down with malaria-induced respiratory complication during the course of treatment. Although parasites were cleared off the circulation, the patient’s condition worsened. He succumbed to multiple complications including acute respiratory distress syndrome and acute renal failure.ResultsSequencing of the malaria parasite DNA from both cases, followed by multiple sequence alignment and phylogenetic tree construction suggested that the causative agent for both malaria cases was P. ovale curtisi.DiscussionIn this report, the differences between both cases were discussed, and the potential capability of P. ovale in causing severe complications and death as seen in this case report was highlighted.ConclusionPlasmodium ovale is potentially capable of causing severe complications, if not death. Complete travel and clinical history of malaria patient are vital for successful diagnoses and treatment. Monitoring of respiratory and renal function of malaria patients, regardless of the species of malaria parasites involved is crucial during the course of hospital admission.

Plasmodium knowlesi Reinfection in Human

To the Editor: In 2004, a large number of patients infected with Plasmodium knowlesi (simian malarial species) were reported in Sarawak, Malaysia (1). P. knowlesi infection was also reported in Peninsular Malaysia (2). Here we report a case of human P. knowlesi reinfection. Phylogenetic sequence analysis shows that the first and second infections were caused by different strains of P. knowlesi.

Tuberculin skin testing among healthcare workers in the University of Malaya Medical Centre, Kuala Lumpur, Malaysia.

OBJECTIVES To determine the occupational risk of Mycobacterium tuberculosis infection among healthcare workers (HCWs) and to examine the utility of tuberculin skin testing in a developing country with a high prevalence of bacille Calmette-Guerin vaccination. DESIGN Tuberculin skin test (TST) survey. SETTING A tertiary-care referral center and a teaching hospital in Kuala Lumpur, Malaysia. PARTICIPANTS HCWs from medical, surgical, and orthopedic wards. INTERVENTION Tuberculin purified protein derivative RT-23 (State Serum Institute, Copenhagen, Denmark) was used for the TST (Mantoux method). RESULTS One hundred thirty-seven (52.1%) and 69 (26.2%) of the HCWs tested had indurations of 10 mm or greater and 15 mm or greater, respectively. Medical ward HCWs were at significantly higher risk of a positive TST reaction than were surgical or orthopedic ward HCWs (odds ratio, 2.18; 95% confidence interval, 1.33 to 3.57; P = .002 for TST positivity at 10 mm or greater) (odds ratio, 2.61; 95% confidence interval, 1.44 to 4.70; P = .002 for TST positivity at 15 mm or greater). A previous TST was a significant risk factor for a positive TST reaction at either 10 mm or greater or 15 mm or greater, but a duration of employment of more than 1 year and being a nurse were only significantly associated with a positive TST reaction at a cut-off point of 15 mm or greater. CONCLUSIONS HCWs at the University of Malaya Medical Centre had an increased risk for M. tuberculosis infection that was significantly associated with the level of occupational tuberculosis exposure. A TST cut-off point of 15 mm or greater may correlate better with M. tuberculosis infection than a cut-off point of 10 mm or greater in settings with a high prevalence of bacille Calmette-Guerin vaccination.

Diagnosis of an imported Plasmodium ovale wallikeri infection in Malaysia

Plasmodium ovale is rare and not exactly known to be autochthonous in Malaysia. There are two distinct forms of the parasite, namely P. ovale curtisi (classic form) and P. ovale wallikeri (variant form). Here, the first sequence confirmed case of an imported P. ovale wallikeri infection in Malaysia is presented. Microscopy found Plasmodium parasites with morphology similar to P. ovale or Plasmodium vivax in the blood films. Further confirmation using polymerase chain reaction (PCR) targeting the small-subunit rRNA gene of the parasite was unsuccessful. Genus-specific PCR was then performed and the product was sequenced and analysed. Sequence analyses confirmed the aetiological agent as P. ovale wallikeri. New species-specific primers (rOVA1v and rOVA2v) were employed and P. ovale wallikeri was finally confirmed. The findings highlight the need to look out for imported malaria infections in Malaysia and the importance of a constantly updated and validated diagnostic technique.