Feasibility and Effectiveness of Basic Lymphedema Management in Leogane, Haiti, an Area Endemic for Bancroftian Filariasis

Lymphatic filariasis is a parasitic disease that is spread by mosquitoes. In tropical countries where lymphatic filariasis occurs, approximately 14 million people suffer from chronic swelling of the leg, known as lymphedema. Repeated episodes of bacterial skin infection (acute attacks) cause lymphedema to progress to its disfiguring form, elephantiasis. To help achieve the goal of eliminating lymphatic filariasis globally, the World Health Organization recommends basic lymphedema management, which emphasizes hygiene, skin care, exercise, and leg elevation. Its effectiveness in reducing acute attack frequency, as well as the role of compressive bandaging, have not been adequately evaluated in filariasis-endemic areas. Between 1995 and 1998, we studied 175 people with lymphedema of the leg in Leogane, Haiti. During Phase I of the study, when compression bandaging was used to reduce leg volume, the average acute attack rate was 1.56 episodes per year; it was greater in people who were illiterate and those who used compression bandages. After March 1997, when hygiene and skin care were emphasized and bandaging discouraged, acute attack frequency significantly decreased to 0.48 episodes per year. This study highlights the effectiveness of hygiene and skin care, as well as limitations of compressive bandaging, in managing lymphedema in filariasis-endemic areas

Secondary mapping of lymphatic filariasis in Haiti-definition of transmission foci in low-prevalence settings.

To eliminate Lymphatic filariasis (LF) as a public health problem, the World Health Organization (WHO) recommends that any area with infection prevalence greater than or equal to 1% (denoted by presence of microfilaremia or antigenemia) should receive mass drug administration (MDA) of antifilarial drugs for at least five consecutive rounds. Areas of low-antigen prevalence (< 1%) are thought to pose little risk for continued transmission of LF. Five low-antigen prevalence communes in Haiti, characterized as part of a national survey, were further assessed for transmission in this study. An initial evaluation of schoolchildren was performed in each commune to identify antigen-positive children who served as index cases for subsequent community surveys conducted among households neighboring the index cases. Global positioning system (GPS) coordinates and immunochromatographic tests (ICT) for filarial antigenemia were collected on approximately 1,600 persons of all ages in the five communes. The relationship between antigen-positive cases in the community and distance from index cases was evaluated using multivariate regression techniques and analyses of spatial clustering. Community surveys demonstrated higher antigen prevalence in three of the five communes than was observed in the original mapping survey; autochthonous cases were found in the same three communes. Regression techniques identified a significantly increased likelihood of being antigen-positive when living within 20 meters of index cases when controlling for age, gender, and commune. Spatial clustering of antigen-positive cases was observed in some, but not all communes. Our results suggest that localized transmission was present even in low-prevalence settings and suggest that better surveillance methods may be needed to detect microfoci of LF transmission

Clustering of antigen positive households by commune using SatScan, version 9.1.1^*.

*<p>Moron was excluded from further analysis because it showed no positive results for antigen status.</p>**<p>p-value was determined using a chi square analysis.</p>***<p>The isotonic Bernoulli cluster analysis decreases the effect as distance from the center increases. This analysis is carried out in 3 steps with increasing radii.</p

Antigen positivity by distance from an index case in the community survey (n = 1290).

<p>Antigen positivity by distance from an index case in the community survey (n = 1290).</p

Maps of Hinche showing clusters of households around index cases.

<p>4a gives an overall view of the households sampled within Hinche. Households containing index cases are denoted by a star and distinguished by letters A–E, households containing a non-index ICT positive person are denoted by a red dot, and households containing no ICT positive persons are denoted by a green dot. 4b shows an example of the proximity to index cases and clustering of households. Letters B and C denote the individual index cases, whose houses are represented by a star. Concentric rings at specified distances indicate which distance from index case category each household falls within. Households denoted by the bright green dot indicate houses that were identified as part of the cluster around index C. There was no significant clustering of households containing ICT positives for index B. 4c. shows the absence of clustered household containing ICT positive persons in proximity to index D.</p

Characteristics of study population tested for filarial antigen status in the community survey^*.

*<p>Total n may differ depending on the number of persons responding to each variable.</p>**<p>p-value was determined using a chi square analysis.</p>***<p>p-value was determined using Fisher's exact methods.</p

Crude sensitivity analysis for influence of distance from index case (m) on antigen status (n = 1290).

*<p>p-value was determined using a chi square analysis.</p>**<p>p-value was determined using Fisher's exact methods.</p

Index and autochthonous index case selection criteria from school survey data 2001–2003.

<p>Index and autochthonous index case selection criteria from school survey data 2001–2003.</p