Imported malaria into Australia: surveillance insights and opportunities

BACKGROUND

Malaria continues to pose a significant burden in endemic countries, many of which lack access to molecular surveillance. Insights from malaria cases in travellers returning to non-endemic areas can provide valuable data to inform endemic country programmes. To evaluate the potential for novel global insights into malaria, we examined epidemiological and molecular data from imported malaria cases to Australia.

METHODS

We analysed malaria cases reported in Australia from 2012 to 2022 using National Notifiable Disease Surveillance System data. Molecular data on imported malaria cases were obtained from literature searches.

RESULTS

Between 2012 and 2022, 3204 malaria cases were reported in Australia. Most cases (69%) were male and 44% occurred in young adults aged 20-39 years. Incidence rates initially declined between 2012 and 2015, then increased until 2019. During 2012-2019, the incidence in travellers ranged from 1.34 to 7.71 per 100 000 trips. Cases were primarily acquired in Sub-Saharan Africa (n = 1433; 45%), Oceania (n = 569; 18%) and Southern and Central Asia (n = 367; 12%). The most common countries of acquisition were Papua New Guinea (n = 474) and India (n = 277). Plasmodium falciparum accounted for 58% (1871/3204) of cases and was predominantly acquired in Sub-Saharan Africa, and Plasmodium vivax accounted for 32% (1016/3204), predominantly from Oceania and Asia. Molecular studies of imported malaria cases to Australia identified genetic mutations and deletions associated with drug resistance and false-negative rapid diagnostic test results, and led to the establishment of reference genomes for P. vivax and Plasmodium malariae.

CONCLUSIONS

Our analysis highlights the continuing burden of imported malaria into Australia. Molecular studies have offered valuable insights into drug resistance and diagnostic limitations, and established reference genomes. Integrating molecular data into national surveillance systems could provide important infectious disease intelligence to optimize treatment guidelines for returning travellers and support endemic country surveillance programmes.

Thrombocytosis and Transaminitis in Infants Born to Women With Inflammatory Bowel Disease Is Associated With Exposure to Maternal Inflammation In Utero

BACKGROUND

Despite reassuring clinical safety data, thrombocytosis, anemia, lymphopenia, and liver function derangements have been observed in infants born to women with inflammatory bowel disease (IBD) treated with thiopurines and biologics. We aimed to define the prevalence, course, associations, and clinical impact of hematological and biochemical abnormalities in such infants.

METHODS

This multicenter prospective cohort study assessed clinical, hematologic, and biochemical outcomes of infants exposed to thiopurines or biologics in utero for management of maternal IBD. Liver transaminases, full blood examination, and infant thiopurine metabolites (where exposed) were taken at delivery and 6 weeks of age. Abnormal results were repeated until normalization. Infants were followed clinically by a pediatric gastroenterologist up to 2 years of age.

RESULTS

A total of 130 infants were included. Thrombocytosis and elevated alanine transaminase (ALT) were seen in over half of infants up to 6 months of age with no significant clinical impact. Elevated ALT was associated with increasing maternal C-reactive protein in second trimester, while thrombocytosis was associated with increasing maternal C-reactive protein and fecal calprotectin in third trimester. Preceding infection and vaccination were associated with an increased risk of elevated alkaline phosphatase at 3 months. In those exposed to thiopurines, increasing maternal 6-methylmercaptopurine at delivery was associated with increased ALT to 6 months.

CONCLUSIONS

Infants born to women with IBD commonly developed thrombocytosis, elevated alkaline phosphatase, and elevated ALT. These findings were associated with exposure to maternal inflammation, elevated 6-methylmercaptopurine at delivery, and infant vaccinations and infections, and had minimal clinical consequence.

Predicting Bilateral Subtypes of Primary Aldosteronism Without Adrenal Vein Sampling: A Systematic Review and Meta-analysis

CONTEXT

Primary aldosteronism (PA) is the most common endocrine cause of hypertension. The final diagnostic step involves subtyping, using adrenal vein sampling (AVS), to determine if PA is unilateral or bilateral. The complete PA diagnostic process is time and resource intensive, which can impact rates of diagnosis and treatment. Previous studies have developed tools to predict bilateral PA before AVS.

OBJECTIVE

Evaluate the sensitivity and specificity of published tools that aim to identify bilateral subtypes of PA.

METHODS

Medline and Embase databases were searched to identify published models that sought to subtype PA, and algorithms to predict bilateral PA are reported. Meta-analysis and meta-regression were then performed.

RESULTS

There were 35 studies included, evaluating 55 unique algorithms to predict bilateral PA. The algorithms were grouped into 6 categories: those combining biochemical, radiological, and demographic characteristics (A); confirmatory testing alone or combined with biochemical, radiological, and demographic characteristics (B); biochemistry results alone (C); adrenocorticotropic hormone stimulation testing (D); anatomical imaging (E); and functional imaging (F). Across the identified algorithms, sensitivity and specificity ranged from 5% to 100% and 36% to 100%, respectively. Meta-analysis of 30 unique predictive tools from 32 studies showed that the group A algorithms had the highest specificity for predicting bilateral PA, while group F had the highest sensitivity.

CONCLUSIONS

Despite the variability in published predictive algorithms, they are likely important for decision-making regarding the value of AVS. Prospective validation may enable medical treatment upfront for people with a high likelihood of bilateral PA without the need for an invasive and resource-intensive test.

Effect of gene variants on opioid dose, pain and adverse effect outcomes in advanced cancer: an explorative study

Aim: Associations between gene variants and opioid net effect are unclear. We conducted an exploratory pharmacogenetic analysis of 35 gene variants and opioid response in advanced cancer. Patients & methods: This multi-center prospective cohort study included clinical data, questionnaires (pain and adverse effects) and DNA (blood). Negative binomial regression and logistic regression were used. Results: Within 54 participants, eight statistically significant associations (p = 0.002-0.038) were observed between gene variants and opioid dose, pain scores or adverse effects, the majority being within the neuroimmune TLR4 pathway (IL1B [rs1143634], IL2 [rs2069762], IL6 [rs1800795], BDNF [rs6265]) and ARRB2 pathway (ARRB2 [rs3786047], DRD2 [rs6275]). Conclusion: Neuroimmune pathway genes may contribute to differences in opioid response in cancer and may be included in future similar studies.

Financial toxicity experienced by rural Australian families with chronic kidney disease

AIM

Chronic kidney disease (CKD) and its treatment places a financial burden on healthcare systems and households worldwide, yet little is known of its financial impact, on those who reside in rural settings. We aimed to quantify the financial impacts and out-of-pocket expenditure experienced by adult rural patients with CKD in Australia.

METHODS

A web based structured survey was completed between November 2020 and January 2021. English speaking participants over 18 years of age, diagnosed with CKD stages 3-5, those receiving dialysis or with a kidney transplant, who lived in a rural location in Australia.

RESULTS

In total 77 (69% completion rate) participated. The mean out of pocket expenses were 5056 AUD annually (excluding private health insurance costs), 78% of households experienced financial hardship with 54% classified as experiencing financial catastrophe (out-of-pocket expenditure greater than 10% of household income). Mean distances to access health services for all rural and remote classifications was greater than 50 kilometres for specialist nephrology services and greater than 300 kilometres for transplanting centres. Relocation for a period greater than 3 months to access care was experienced by 24% of participants.

CONCLUSION

Rural households experience considerable financial hardship due to out-of-pocket costs in accessing treatment for CKD and other health-related care, raising concerns about equity in Australia, a high-income country with universal healthcare.

Contemporary updates on ventricular arrhythmias: from mechanisms to management

Ventricular arrhythmias (VAs) are a group of heart rhythm disorders that can be life-threatening and cause significant morbidity. VA in the presence of structural heart disease (SHD) has distinct prognostic implications and requires a comprehensive and multifaceted approach for investigation and management. Early specialist referral should be considered for all patients with VA. Particular urgency is recommended in patients with syncope, nonsustained/sustained VA on Holter monitor and SHD on cardiac imaging because of the heightened risk of sudden cardiac death. Comprehensive phenotyping is recommended for most patients with VA, encompassing noninvasive cardiac functional testing, multimodality imaging and genetic testing in select circumstances. Management of idiopathic VA is guided heavily by symptom burden and the presence of ventricular systolic impairment. In SHD, guideline-directed heart failure therapy and device implantation are critical considerations. Whilst commonly used and well-established, antiarrhythmic drugs can be hampered by toxicity and failure of adequate arrhythmia control. Catheter ablation is increasingly being considered a feasible first-line alternative to medical therapy, where outcomes are influenced by disease aetiology and scar burden in SHD. Catheter ablation is associated with reduced arrhythmia recurrence and burden and improved quality of life at follow-up.

Estimating mean population salt intake in Fiji and Samoa using spot urine samples

BACKGROUND

There is an increasing interest in finding less costly and burdensome alternatives to measuring population-level salt intake than 24-h urine collection, such as spot urine samples. However, little is known about their usefulness in developing countries like Fiji and Samoa. The purpose of this study was to evaluate the capacity of spot urine samples to estimate mean population salt intake in Fiji and Samoa.

METHODS

The study involved secondary analyses of urine data from cross-sectional surveys conducted in Fiji and Samoa between 2012 and 2016. Mean salt intake was estimated from spot urine samples using six equations, and compared with the measured salt intake from 24-h urine samples. Differences and agreement between the two methods were examined through paired samples t-test, intraclass correlation coefficient analysis, and Bland-Altman plots and analyses.

RESULTS

A total of 414 participants from Fiji and 725 participants from Samoa were included. Unweighted mean salt intake based on 24-h urine collection was 10.58 g/day (95% CI 9.95 to 11.22) in Fiji and 7.09 g/day (95% CI 6.83 to 7.36) in Samoa. In both samples, the INTERSALT equation with potassium produced the closest salt intake estimate to the 24-h urine (difference of - 0.92 g/day, 95% CI - 1.67 to - 0.18 in the Fiji sample and + 1.53 g/day, 95% CI 1.28 to 1.77 in the Samoa sample). The presence of proportional bias was evident for all equations except for the Kawasaki equation.

CONCLUSION

These data suggest that additional studies where both 24-h urine and spot urine samples are collected are needed to further assess whether methods based on spot urine samples can be confidently used to estimate mean population salt intake in Fiji and Samoa.