The Effect of Single or Repeated Home Visits on the Hanging and Use of Insecticide-Treated Mosquito Nets following a Mass Distribution Campaign - A Cluster Randomized, Controlled Trial

<div><p>Background</p><p>Study objective was to evaluate the effectiveness of commonly used post-campaign hang-up visits on the hanging and use of campaign nets.</p><p>Methods</p><p>A cluster-randomized trial was carried out in Uganda following an ITN distribution campaign. Five clusters (parishes, consisting of ∼11 villages each) were randomly selected for each of the three study arms with between 7,534 and 9,401 households per arm. Arm 1 received one hang-up visit, while Arm 2 received two visits by volunteers four and seven months after the campaign. Visits consisted of assistance hanging the net and education on net use. The control arm was only exposed to messages during the campaign itself. Three cross-sectional surveys with a two-stage cluster sampling design, representative of the study populations, were carried out to capture the two key outcome variables of net hanging and ITN use. Sample size was calculated to detect at least a 15 percentage-points change in net use, and was 1811 at endline. The analysis used an intention-to-treat approach.</p><p>Findings</p><p>Both hanging and use of ITN increased during follow-up in a similar way in all three study arms. The proportion of the population using an ITN the previous night was 64.0% (95% CI 60.8, 67.2), for one additional visit, 68.2% (63.8, 72.2) for two visits and 64.0% (59.4, 68.5) for the control. The proportion of households with all campaign nets hanging increased from 55.7% to 72.5% at endline (p<0.0005 for trend), with no difference between study arms. Financial cost per household visited was estimated as USD 2.33 for the first visit and USD 2.24 for the second.</p><p>Conclusions</p><p>Behavior change communication provided during the campaign or through other channels was sufficient to induce high levels of net hanging and use and additional “hang-up” activities were not cost-effective.</p></div

Household characteristics and ITN ownership.

<p>HH = household.</p><p>Household characteristics and ITN ownership.</p

Reasons for non-use of ITN: final evaluation at survey 3 (N = 1391).

<p>Reasons for non-use of ITN: final evaluation at survey 3 (N = 1391).</p

Recall of hang-up visit intervention.

<p>Based on self-reporting by respondent (survey) and records from the intervention implementing agency.</p><p>Recall of hang-up visit intervention.</p

Difference of differences for ITN use by <i>de facto</i> population, adjusting for study design.

<p>Difference of differences for ITN use by <i>de facto</i> population, adjusting for study design.</p

Map of Uganda with Kamuli District (2010 borders) and study clusters (parishes).

<p>Numbers represent the five geographical strata; orange: study arm 1; yellow: study arm 2; green study arm 3. Shaded areas were excluded from selection (details see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0119078#sec006" target="_blank">methods</a> section)</p

Proportion of households with any campaign nets that had all of their nets hanging on the day of the survey (OR = crude Odds Ratio).

<p>Proportion of households with any campaign nets that had all of their nets hanging on the day of the survey (OR = crude Odds Ratio).</p

Use gap defined as population with access to an ITN but not using an ITN by survey and study arm.

<p>Error bars represent 95% confidence intervals.</p

Proportion of the <i>de facto</i> population using an ITN the previous night (OR = crude Odds Ratio).

<p>Proportion of the <i>de facto</i> population using an ITN the previous night (OR = crude Odds Ratio).</p

Novel Cross-Border Approaches to Optimise Identification of Asymptomatic and Artemisinin-Resistant Plasmodium Infection in Mobile Populations Crossing Cambodian Borders

<div><p>Background</p><p>Human population movement across country borders presents a real challenge for malaria control and elimination efforts in Cambodia and its neighbouring countries. To quantify <i>Plasmodium</i> infection among the border-crossing population, including asymptomatic and artemisinin resistant (AR) parasites, three official border crossing points, one from each of Cambodia's borders with Thailand, Laos and Vietnam, were selected for sampling.</p><p>Methods and Findings</p><p>A total of 3206 participants (of 4110 approached) were recruited as they crossed the border, tested for malaria and interviewed. By real-time polymerase chain reaction (RT-PCR), 5.4% of all screened individuals were found to harbour <i>Plasmodium</i> parasites. The proportion was highest at the Laos border (11.5%). Overall there were 97 <i>P</i>. <i>vivax</i> (55.7%), 55 <i>P</i>. <i>falciparum</i> (31.6%), two <i>P</i>. <i>malariae</i> (1.1%) and 20 mixed infections (11.5%). Of identified infections, only 20% were febrile at the time of screening. Of the 24 <i>P</i>. <i>falciparum</i> samples where a further PCR was possible to assess AR, 15 (62.5%) had mutations in the K13 propeller domain gene, all from participants at the Laos border point. Malaria rapid diagnostic test (RDT) pLDH/HRP-2 identified a positivity rate of 3.2% overall and sensitivity compared to RT-PCR was very low (43.1%). Main individual risk factors for infection included sex, fever, being a forest-goer, poor knowledge of malaria prevention methods and previous malaria infection. Occupation, day of the week and time of crossing (morning vs. afternoon) also appeared to play an important role in predicting positive cases.</p><p>Conclusions</p><p>This study offers a novel approach to identify asymptomatic infections and monitor AR parasite flow among mobile and migrant populations crossing the borders. Similar screening activities are recommended to identify other hot borders and characterise potential hot spots of AR. Targeted “customised” interventions and surveillance activities should be implemented in these sites to accelerate elimination efforts in the region.</p></div