Phiri, K. S. | bioRxiv Science

bioRxiv2021

Identifying Plasmodium falciparum transmission patterns through parasite prevalence and entomological inoculation rate

Monitoring malaria transmission is a critical component of efforts to achieve targets for elimination and eradication. Two commonly monitored metrics of transmission intensity are parasite prevalence (PR) and the entomological inoculation rate (EIR). Using geostatistical methods, we investigate the relationship between Plasmodium falciparum PR and EIR using data collected over 38 months in a rural area of Malawi. Our results indicate that hotspots identified through the EIR and PR partly overlapped during high transmission seasons but not during low transmission seasons. The estimated relationship showed a one-month delayed effect of EIR on PR such that at low transmission levels increases in EIR are associated with rapid rise in PR, but at high transmission levels, decreases in EIR do not translate into notable reductions in PR. Our study emphasises the need for integrated malaria control strategies that combines vector and human host managements monitored by both entomological and parasitaemia indices.

physiology↗

bioRxiv2019

Severe anaemia complicating HIV in Malawi; multiple co-existing aetiologies are associated with high mortality.

BackgroundSevere anaemia is a major cause of morbidity and mortality in HIV-infected adults living in resource-limited countries. Comprehensive data on the aetiology is lacking and needed to improve outcomes.\n\nMethodsHIV-infected adults with severe (haemoglobin [≤]70g/l) or very severe anaemia (haemoglobin [≤]50 g/l) were recruited at Queen Elizabeth Central Hospital, Blantyre, Malawi. Fifteen potential causes of severe anaemia of anaemia and associations with anaemia severity and mortality were explored.\n\nResults199 patients were enrolled: 42.2% had very severe anaemia and 45.7% were on ART. Over two potential causes for anaemia were present in 94% of the patients; including iron deficiency (55.3%), underweight (BMI<20: 49.7%), TB-infection (41.2%) and unsuppressed HIV-infection (viral load >1000 copies/ml) (73.9%). EBV/CMV co-infection (16.5%) was associated with very severe anaemia (OR 2.8 95% CI 1.1-6.9). Overall mortality was high (53%; 100/199) with a median time to death of 16 days. Death was associated with folate deficiency (HR 2.2; 95% CI 1.2-3.8) and end stage renal disease (HR 3.2; 95% CI 1.6-6.2).\n\nConclusionMortality among severely anaemic HIV-infected adults is strikingly high. Clinicians must be aware of the urgent need for a multifactorial approach, including starting or optimising HIV treatment; considering TB treatment, nutritional support and attention to potential renal impairment.

immunology↗