Exposure to deltamethrin affects development of Plasmodium falciparum inside wild pyrethroid resistant Anopheles gambiae s.s. mosquitoes in Uganda.

BACKGROUND: Pyrethroid resistance in African vector mosquitoes is a threat to malaria control. Resistant mosquitoes can survive insecticide doses that would normally be lethal. We studied effects of such doses on Plasmodium falciparum development inside kdr-resistant Anopheles gambiae s.s. in Uganda. METHODS: We collected An. gambiae s.s. homozygous for kdr-L1014S mutation, fed them on blood samples from 42 P. falciparum-infected local patients, then exposed them either to nets treated with sub-lethal doses of deltamethrin or to untreated nets. After seven days, we dissected 692 mosquitoes and examined their midguts for oocysts. Prevalence (proportion infected) and intensity of infection (number of oocysts per infected mosquito) were recorded for each group. RESULTS: Both prevalence and intensity of infection were significantly reduced in deltamethrin-exposed mosquitoes, compared to those exposed to untreated nets. With low doses (2.5-5.0 mg/m(2)), prevalence was reduced by 59% (95% CI = 22%-78%) and intensity by 41% (95% CI = 25%-54%). With high doses (10-16.7 mg/m(2)), prevalence was reduced by 80% (95% CI = 67%-88 %) and intensity by 34 % (95 % CI = 20%-46%). CONCLUSIONS: We showed that, with locally-sampled parasites and mosquitoes, doses of pyrethroids that are sub-lethal for resistant mosquitoes can interfere with parasite development inside mosquitoes. This mechanism could enable pyrethroid-treated nets to prevent malaria transmission despite increasing vector resistance

Community dialogues for child health: results from a qualitative process evaluation in three countries

Background: Across the developing world, countries are increasingly adopting the integrated community case management of childhood illnesses (iCCM) strategy in efforts to reduce child mortality. This intervention\u2019s effectiveness is dependent on community adoption and changes in care-seeking practices. We assessed the implementation process of a theory-driven community dialogue (CD) intervention specifically designed to strengthen the support and uptake of the newly introduced iCCM services and related behaviours in three African countries. Methods: A qualitative process evaluation methodology was chosen and used secondary project data and primary data collected in two districts of each of the three countries, in purposefully sampled communities. The final data set included 67 focus group discussions and 57 key informant interviews, totalling 642 respondents, including caregivers, CD facilitators community leaders, and trainers. Thematic analysis of the data followed the \u2018Framework Approach\u2019 utilising both a deduction and induction process. Results: Results show that CDs contribute to triggering community uptake of and support for iCCM services through filling health information gaps and building cooperation within communities. We found it to be an effective approach for addressing social norms around child care practices. This approach was embraced by communities for its flexibility and value in planning individual and collective change. Conclusions: Regular CDs can contribute to the formation of new habits, particularly in relation to seeking timely care in case of child sickness. This study also confirms the value of process evaluation to unwrap the mechanisms of community mobilisation approaches in context and provides key insights for improving the CD approach

Current malaria infection, previous malaria exposure, and clinical profiles and outcomes of COVID-19 in a setting of high malaria transmission: an exploratory cohort study in Uganda

Background: The potential effects of SARS-CoV-2 and Plasmodium falciparum co-infection on host susceptibility and pathogenesis remain unknown. We aimed to establish the prevalence of malaria and describe the clinical characteristics of SARS-CoV-2 and P falciparum co-infection in a high-burden malaria setting. Methods: This was an exploratory prospective, cohort study of patients with COVID-19 who were admitted to hospital in Uganda. Patients of all ages with a PCR-confirmed diagnosis of SARS-CoV-2 infection who had provided informed consent or assent were consecutively enrolled from treatment centres in eight hospitals across the country and followed up until discharge or death. Clinical assessments and blood sampling were done at admission for all patients. Malaria diagnosis in all patients was done by rapid diagnostic tests, microscopy, and molecular methods. Previous P falciparum exposure was determined with serological responses to a panel of P falciparum antigens assessed using a multiplex bead assay. Additional evaluations included complete blood count, markers of inflammation, and serum biochemistries. The main outcome was overall prevalence of malaria infection and malaria prevalence by age (including age categories of 0–20 years, 21–40 years, 41–60 years, and >60 years). The frequency of symptoms was compared between patients with COVID-19 with P falciparum infection versus those without P falciparum infection. The frequency of comorbidities and COVID-19 clinical severity and outcomes was compared between patients with low previous exposure to P falciparum versus those with high previous exposure to P falciparum. The effect of previous exposure to P falciparum on COVID-19 clinical severity and outcomes was also assessed among patients with and those without comorbidities. Findings: Of 600 people with PCR-confirmed SARS-CoV-2 infection enrolled from April 15, to Oct 30, 2020, 597 (>99%) had complete information and were included in our analyses. The majority (502 [84%] of 597) were male individuals with a median age of 36 years (IQR 28–47). Overall prevalence of P falciparum infection was 12% (95% CI 9·4–14·6; 70 of 597 participants), with highest prevalence in the age groups of 0–20 years (22%, 8·7–44·8; five of 23 patients) and older than 60 years (20%, 10·2–34·1; nine of 46 patients). Confusion (four [6%] of 70 patients vs eight [2%] of 527 patients; p=0·040) and vomiting (four [6%] of 70 patients vs five [1%] of 527 patients; p=0·014] were more frequent among patients with P falciparum infection than those without. Patients with low versus those with high previous P falciparum exposure had a increased frequency of severe or critical COVID-19 clinical presentation (16 [30%] of 53 patients vs three [5%] of 56 patients; p=0·0010) and a higher burden of comorbidities, including diabetes (12 [23%] of 53 patients vs two [4%] of 56 patients; p=0·0010) and heart disease (seven [13%] of 53 patients vs zero [0%] of 56 patients; p=0·0030). Among patients with no comorbidities, those with low previous P falciparum exposure still had a higher proportion of cases of severe or critical COVID-19 than did those with high P falciparum exposure (six [18%] of 33 patients vs one [2%] of 49 patients; p=0·015). Multivariate analysis showed higher odds of unfavourable outcomes in patients who were older than 60 years (adjusted OR 8·7, 95% CI 1·0–75·5; p=0·049). Interpretation: Although patients with COVID-19 with P falciparum co-infection had a higher frequency of confusion and vomiting, co-infection did not seem deleterious. The association between low previous malaria exposure and severe or critical COVID-19 and other adverse outcomes will require further study. These preliminary descriptive observations highlight the importance of understanding the potential clinical and therapeutic implications of overlapping co-infections. Funding: Malaria Consortium (USA)

MOESM1 of What drives the consistent use of long-lasting insecticidal nets over time? A multi-method qualitative study in mid-western Uganda

Additional file 1. Full transcripts of the three stories selected as part of the study’s MSC analysis component

Pioneer RDT comms data file

Main data file for Pioneer study and associated manuscript focused on how patients and health workers interact around malaria rapid diagnostic testing and how the tests are experienced by patients in practice (located western Uganda). The file contains full indexed dataset from patient interviews as well as full observation data

Data from: How do patients and health workers interact around malaria rapid diagnostic testing, and how are the tests experienced by patients in practice? A qualitative study in western Uganda

Main data file for Pioneer study and associated manuscript focused on how patients and health workers interact around malaria rapid diagnostic testing and how the tests are experienced by patients in practice (located western Uganda). The file contains full indexed dataset from patient interviews as well as full observation data

Demographic characteristics of observed patients.

<p>Demographic characteristics of observed patients.</p