Plasmodium ovale infection in Sri Lanka: distant exposure and incidental detection of hyperparasitemia: a case report

BACKGROUND

Plasmodium ovale malaria, which was previously endemic to tropical Africa and the Southwest Pacific islands is now being reported from parts of Asia. In Sri Lanka, the indigenous transmission of malaria has not been documented since October 2012. Since then, there have been several imported cases of malaria, including P. ovale, which have been detected sporadically. The reporting case of P. ovale was imported and detected incidentally in 2021, with several atypical presentations.

CASE PRESENTATION

A 40-year-old Sri Lankan medical doctor developed continuous fever with chills, rigors, and dysuria a day following removal of a large lipoma at the root of the neck under general anaesthesia. When the fever has been responding to antibiotics, on the 4th postoperative day a mild thrombocytopenia on complete blood count was detected. A blood smear which was done on the 5th postoperative day incidentally found a malaria parasite and confirmed as Plasmodium ovale with a density of 6535 parasites/microliter on the same day. He never had malaria in the past, but he had worked in South Sudan 1 year ago and visited India six months ago. On the 6th postoperative day, he was treated with chloroquine, and hyperparasitemia reduced rapidly by the next day. As the fever recurred with clinical deterioration, he was treated with different antibiotics. During the course of the illness, he did not develop pallor, or icterus except for a palpable soft spleen. The parasite count was zero on the 9th postoperative day and his fever subsided on the next day. Further, he was treated with primaquine to prevent future relapse and transmission.

CONCLUSION

A long incubation period, incidental detection of P ovale in a blood smear, and hyperparasitaemia are the atypical presentations of this case. Postoperative bacterial infection and stress may have reactivated the dormant malaria (hyponozoites) in this patient with an unusual picture. Coinfection of malaria with bacterial sepsis is a challenge in the management of the patient. As the Anopheles mosquito vector exists in Sri Lanka, the risk of indigenous transmission is high from such imported cases of P. ovale.

Study protocol: characterising the clinical, epidemiological and aetiological aspects of leptospirosis in Sri Lanka: a hospital based clinico-epidemiological study

INTRODUCTION

Sri Lanka has one of the highest incidences of leptospirosis worldwide. We hypothesised that different geographical locations and patient context will have a distinct molecular epidemiology of leptospirosis, based on microgeographical characteristics related to regiona-specific Leptospira predominance. Our objective is to characterise the clinical, epidemiological and molecular aspects of leptospirosis in Sri Lanka to understand disease progression, risk factors and obtain isolates of Leptospira.

METHODS AND ANALYSIS

We designed a multicentre prospective study in Sri Lanka to recruit undifferentiated febrile patients and conduct follow-ups during hospital stays. Patients will be recruited from outpatient departments and medical wards. This study will be conducted at two main sites (Anuradhapura and Peradeniya) and several additional sites (Awissawella, Ratnapura and Polonnaruwa). Blood and urine will be collected from patients on the day of admission to the ward or presentation to the outpatient department. Bedside inoculation of 2-4 drops of venous blood will be performed with Ellinghausen-McCullough-Johnson-Harris (EMJH) semisolid media supplemented with antibiotics. Regionally optimised microscopic agglutination test, culture and qPCR-evidence will be performed to confirm the presence of Leptospira in blood which in turn will confirm the presence of disease. Whole genome sequencing will be carried out for all isolates recovered from patients. Multilocus sequence typing (MLST) will be used for the genotyping of new isolates. Sri Lankan isolates will be identified using three published MLST schemes for Leptospira.

ETHICS AND DISSEMINATION

Ethical clearance for the study was obtained from Ethics Review Committees (ERC), Medicine and Allied Sciences (FMAS), Rajarata University of Sri Lanka (RUSL) and University of Peradeniya. All genomic data generated through this project will be available at GenBank. Anonymised data will be deposited at the ERC, FMAS, RUSL.

Thrombotic microangiopathy and acute kidney injury in hump-nosed viper (Hypnale species) envenoming: a descriptive study in Sri Lanka

Hump-nosed viper (Hypnale species) bites are common in Sri Lanka and a proportion of these bites lead to coagulation abnormalities and acute kidney injury (AKI). We observed thrombotic microangiopathy (TMA) among some of these patients, but its contribution to severity of AKI and other morbidities remains unknown. Thus, we report a case series of TMA following hump-nosed viper bite addressing the complications and renal out comes in Sri Lanka. This was a prospective observational study carried out at the nephrology unit, Kandy in Sri Lanka from October 2010 to October 2011 and included 11 patients with AKI following hump-nosed viper bites. All eleven cases needed renal replacement therapy (RRT) with intermittent haemodialysis for a period of 1-5 weeks. Of them, 7 patients developed TMA with evidence of microangiopathic haemolytic anaemia (MAHA), thrombocytopenia and severe anaemia needing multiple blood transfusions. They needed longer duration of RRT (range 2-5 weeks); 2 patients developed chronic kidney disease and two died during acute stage. Autopsy study found thrombosis of micro-vessels. Thrombotic microangiopathy could be a causative pathology of AKI in hump-nosed viper bite carrying poor outcome.

Parallels between Russell's viper (Daboia russelii) and hump-nosed viper (Hypnale species) bites in the central hills of Sri Lanka amidst the heavy burden of unidentified snake bites

OBJECTIVE

To describe the epidemiology of snake bite in the region and attempt to compare proven Russell's viper with hump-nosed viper bites.

METHODS

All snake bite admissions to the Toxicology Unit of Teaching Hospital Peradeniya over three year from 2006 were included.

RESULTS

Of the 776 snakebites, 665(86%) were unidentified and non-envenomed. Hump-nosed viper and Russell's viper accounted for 55(7%) and 40(5%) bites respectively, of them, incriminated snakes were found in 36(65%) and 19(48%) cases. The cobra bites-5, krait bites-0. The median ages: Russell's viper bites-41(range 16-66), hump-nosed viper bites-42(range 15-75). The gender incidence, time of bite (>58% daytime) were similar. In hump-nosed viper bite; upper limb involved in 13(36%), happened at home garden in 22(61%), none in paddy fields. In Russell's viper bite; 6(33%) occurred in paddy fields. Dry bites were similar at 5%. In hump-nosed viper bite: local effects 94%, coagulopathy 3%, acute renal failure 3% and one patient died. In Russell's viper bite; local effects 84%, coagulopathy 53%, neurotoxicity 21%. Abdominal pain occurred only in Russell's viper bites 10(53%).

CONCLUSIONS

Overwhelming numbers of unidentified, non-envenomed snakebites are common in the central hills. Some distinctive differences were observed between Russell's viper and hump-nosed viper bites.

Cardiac involvement in dengue virus infections during the 2004/2005 dengue fever season in Sri Lanka

Sri Lanka experienced a dramatic increase in dengue cases (15,400) in the 2004 - 2005 season. We carried out a prospective study to investigate cardiac involvement in dengue virus infected patients during the 2004 - 2005 season in Peradeniya, Central Province, Sri Lanka. Cardiac involvement was defined as elevated levels of myoglobin, creatine kinase-muscle brain-type, N-terminal pro-brain natriuretic peptide, heart-type fatty acid-binding protein and troponin T. Twenty-five percent of dengue virus infected patients had one or more of the above tests with abnormal results.

Root Surface Caries in Older Individuals from Sri Lanka

The aim of the present study was to assess the prevalence and factors associated with root surface caries in older individuals from Sri Lanka. A total of 600 urban subjects aged 60 years and above was selected using a two-stage cluster sampling combined with probability-proportionate-to-size technique. The data were collected by means of an interviewer-administered questionnaire and an oral examination. The mean number of teeth present was 13.4 +/- 8.7. The prevalence of root surface caries was 89.7%. The mean number of root surfaces with decay or fillings and the mean root caries index (RCI) per subject were 3.8 and 25.0%, respectively. In both arches, the molars were the most affected by root caries. A multiple logistic regression analysis showed that betel chewing (OR = 0.36; 95% CI 0.20, 0.65), being >80 years of age (OR = 0.24; CI 0.09, 0.57), number of retained teeth (OR = 0.88; CI 0.83, 0.93) and number of root surfaces with recession (OR = 1.03; CI 1.01, 1.07) were significantly associated with the presence of root surface caries. In conclusion, it was evident from the study that the prevalence of root surface caries was high in this group of older individuals. Chewing betel, age, number of retained teeth and the number of root surfaces with recession emerged as significant predictors of root caries.