A nocturnal Lymphatic Filariasis study

This blog was prepared by HKI Field Intern and Guest Blogger, Justin Graves. Justin spent six months working with HKI’s Neglected Tropical Diseases (NTD) team in Guinea and is currently an MPH Candidate at Columbia University.

When searching for a practicum site, I was keen to pursue fieldwork as I lacked experience in this area of public health. The projects at HKI Guinea presented a chance to gain skills working in the field by applying concepts and theories.

After 4 months of paperwork during the peak of Guinea’s rainy season, the first fieldwork activity presented itself and with it an opportunity to work with the infectious disease team on lymphatic filariasis (LF) research. To put the disease in perspective,  the World Health Organization (WHO) considers LF to be a leading cause of long-term and permanent disability, and tackling the disease is critical to promote health in Asia and Africa. The LF situation in Guinea presents a major burden across the country. Recent mapping studies have established that approximately 4.5 million people are at risk for this debilitating disease. That is almost half of Guinea’s total population, which is estimated somewhere between 10 and 11 million people.

Commonly known as elephantiasis, LF causes severe health issues. While not considered a fatal disease, symptoms include damage to lymph nodes, to lymphatic vessels, and to the kidneys. If left untreated, chronic tissue swelling leads to elephantiasis (skin and tissue thickening) of the legs and genitals. With a weakened immune system also comes an increased risk of bacterial infection.

Many contract LF during childhood but don’t show symptoms until after adolescence. Disease progression evolves with aging and irreversible damage occurs once the disease fully manifests itself during adulthood. Pain and temporary disability lead to permanent disability and disfigurement and LF causes social stigma and a loss of wage-earning capability that is closely associated with poverty.

On a positive note, LF is highly treatable if cases are identified at early stages. It is also preventable if transmission rates are broken. The WHO has advised a 65% minimum effective coverage rate of mass drug administration with preventative medicines. To determine which communities are eligible for treatment, blood samples must be taken from community members between 10pm and 2am due to the fact that the parasitic worms that cause LF circulate at night.  The blood samples are screened for microscopic parasites that indicate LF infection. This test is referred to as a microfilaraemiae study.

To prepare for the mass drug distribution scheduled in early 2013, microfilaraemiae studies are needed to provide baseline data from which to evaluate the impact of MDA campaigns and gauge community health improvement. For this purpose, two teams of entomologists, microbiologists, epidemiologists, and doctors were assembled from HKI and the Ministry of Health. Enter one enthusiastic intern. The mission of my team was to evaluate microfilaraemiae in remote villages, located in Upper Guinea and the Forest Region. After two days of postponing our departure, I was ecstatic to finally be on the road.

Our drive to the first village showcased spectacular landscapes; the region is known for diverse environments and rapid changes in climate. The dense assortment of palm trees and lush vegetation gave way to low-lying arid grasslands and sparsely scattered woodland plains. As the environment changed so did the colors – the rolling green hills flowed into the golden yellow fields of the interior of the country. The air was drier than on the coast and the horizon sharper. As we approached our destination, the road changed as well. The land cruiser and pick-up truck convoy slowly navigated their way around pot-holed and eroded concrete roads that lead to dirt trails carving through the grasslands. The personnel and equipment finally arrived at our first site, and we dusted off that night before contacting the local authorities.

The sampling process is a wonderful confirmation that the enormous amount of preparation and efforts sensitizing the community was worth the sweat. Numbers transform into faces, statistics turn into village communities, and the people you set out to impact cease being stuck in reports. Ghosts approach on footpaths from the grasslands, their dark silhouettes becoming distinguishable as men, women, and children. Theory instantly becomes reality and families stare at you from across a table, their faces lit by a 60-watt bulb. Handshakes and registration by census questionnaires are done over the rumble of a power generator, and participants are then asked to move to a sampling table. To collect the data, we prick participants’ index fingers with a sterile needle from which three blood films are spread onto labeled microscope slides. As the night progresses, crowds gather around the work tables and people assemble to watch LF documentaries displayed by a projector. After what seems like less than an hour, four have already passed, the people have gone, and it is two in the morning.

A few days later and with more than 300 participants sampled, our convoy left Upper Guinea and followed the southeast curve of the country’s crescent shape, heading towards the Forest Region. This is an area that was ravaged by the wars of Sierra Leone and Liberia, the conflicts spilling over the border and displacing many refugees who sought shelter in the forests of Guinea.

The landscape changed again as we drove into the forest towards the next village, located 100km south at the border of Sierra Leone and Liberia. The flat grasslands quickly gave way to the evergreen forests of trees and palms, standing tall and densely covering steep hills. Passing rice fields and plantations of rubber, coffee and cocoa trees, the road became treacherous as we plunged into the heart of the forest. Those 100km took 12 hours to complete as the traveling conditions deteriorated and the humidity level rose. The path sometimes disappearing entirely, we frequently had to scout the way and dig out the vehicles that had sunk into the soft red clay, loosened by the violent forest storms. That night we finally arrived famished and filthy from the journey, and were able to eat and rest for a few hours before starting our first night of sample collection.

After two weeks of work we had driven 1,947km to sample more than 600 people. Our mobile lab worked anywhere — at a local hospital, in a guesthouse, in villages where we slept. The work was exhilarating and finding positive cases brought mixed feelings – that of excitement at finding microfilaria, but also of sadness in remembering the faces of those infected with LF. It is comforting to know that our work signals the beginning of treatment for the entire health district. The village life was a wonderfully invigorating experience and a poignant reminder that the statistics we read are not just numbers.

African proverb of the month: “From above the duck appears calm but it swims frenetically beneath the surface.”


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Categories: Africa, Preventing Blindness

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