Cross-Reactivity of Filariais ICT Cards in Areas of Contrasting Endemicity of Loa loa and Mansonella perstans in Cameroon: Implications for Shrinking of the Lymphatic Filariasis Map in the Central African Region

Background Immunochromatographic card test (ICT) is a tool to map the distribution of Wuchereria bancrofti. In areas highly endemic for loaisis in DRC and Cameroon, a relationship has been envisaged between high L. loa microfilaria (Mf) loads and ICT positivity. However, similar associations have not been demonstrated from other areas with contrasting levels of L. loa endemicity. This study investigated the cross-reactivity of ICT when mapping lymphatic filariasis (LF) in areas with contrasting endemicity levels of loiasis and mansonellosis in Cameroon

Detecting and staging podoconiosis cases in North West Cameroon: positive predictive value of clinical screening of patients by community health workers and researchers

Background The suitability of using clinical assessment to identify patients with podoconiosis in endemic communities has previously been demonstrated. In this study, we explored the feasibility and accuracy of using Community Health Implementers (CHIs) for the large scale clinical screening of the population for podoconiosis in North-west Cameroon. Methods Before a regional podoconiosis mapping, 193 CHIs and 50 health personnel selected from 6 health districts were trained in the clinical diagnosis of the disease. After training, CHIs undertook community screening for podoconiosis patients under health personnel supervision. Identified cases were later re-examined by a research team with experience in the clinical identification of podoconiosis. Results Cases were identified by CHIs with an overall positive predictive value (PPV) of 48.5% [34.1–70%]. They were more accurate in detecting advanced stages of the disease compared to early stages; OR 2.07, 95% CI = 1.15–3.73, p = 0.015 for all advanced stages). Accuracy of detecting cases showed statistically significant differences among health districts (χ2 = 25.30, p = 0.0001). Conclusion Podoconiosis being a stigmatized disease, the use of CHIs who are familiar to the community appears appropriate for identifying cases through clinical diagnosis. However, to improve their effectiveness and accuracy, more training, supervision and support are required. More emphasis must be given in identifying early clinical stages and in health districts with relatively lower PPVs

Logistic regression analysis of ICT results according to <i>L</i>. <i>loa</i> load among the Mf carriers.

<p>Numbers in brackets are percentages.</p><p>Logistic regression analysis of ICT results according to <i>L</i>. <i>loa</i> load among the Mf carriers.</p

Correlation between ICT positivity rate and <i>L</i>. <i>loa</i> Mf prevalence.

<p>Correlation between ICT positivity rate and <i>L</i>. <i>loa</i> Mf prevalence.</p

Infection profile of ICT positives cases with respect to <i>L</i>. <i>loa</i> and <i>M</i>. <i>perstans</i> infection status using day blood.

<p>Infection profile of ICT positives cases with respect to <i>L</i>. <i>loa</i> and <i>M</i>. <i>perstans</i> infection status using day blood.</p

Percentage of positive results using ICT card according to the <i>L</i>. <i>loa</i> load of microfilariae.

<p>R = 0.438; p < 0.001</p><p>Percentage of positive results using ICT card according to the <i>L</i>. <i>loa</i> load of microfilariae.</p

Map of the study area.

<p>Map of the study area.</p

Gender and age-related prevalence of ICT test card, lymphoedema and diurnal microfilaraemia (TBF).

<p>No <i>W</i>. <i>bancrofti</i> Mf were found in ICT positive and lymphoedema cases.</p><p>Gender and age-related prevalence of ICT test card, lymphoedema and diurnal microfilaraemia (TBF).</p

Infection profile of lymphoedema cases with respect to <i>L</i>. <i>loa</i> and <i>M</i>. <i>perstans</i> infection status using day blood.

<p>Infection profile of lymphoedema cases with respect to <i>L</i>. <i>loa</i> and <i>M</i>. <i>perstans</i> infection status using day blood.</p

Age distribution of the study population.

<p>Age distribution of the study population.</p