Common to Latin America, Caribbean and Sub Saharan Africa, the colloquially
named 'jigger flea' is known to cause significant debilitation in areas of
deprived resources and infrastructure. Tungiasis, a neglected ectoparasitic
disease, arises when the female jigger flea, Tunga penetrans, burrows into the
epidermis of its host.
The jigger flea is the smallest known flea,
measuring under 1mm in length (Feldmeier et al., 2004, p. 279). Having entered
its host (both humans and domesticated animals), the gravid female flea
undergoes substantial growth, growing to around 2000 times its size in six days
(Figure 1).Embedded with its hindquarters at the surface of the skin, the flea
is evident as a distinct, characteristic lesion on the skin; a globular white
mass with a black dot at its centre (Joseph et al., 2006, p. 971). This slight
perforation of the skin not only allows for the flea to respire, but also for
the discharge of newly made eggs. Within a week, up to 200 eggs are deposited
onto the ground. These eggs then hatch into Tunga penetrans larvae which feed on
organic detritus and develop, via a pupal stage, into a fully grown jigger flea.
Re-infestation occurs and the cycle is complete (Gordon, 1941, p. 48).
Writing in 1525, Gonzalez Fernandez de Oviedo y Valdes is thought to be the
first to document the flea in South America. It is believed the jigger flea
eventually left the confines of the Americas amongst the sand ballast of the
Thomas Mitchell, a ship travelling from Brazil to Angola in 1872 (Gordon, 1941,
p. 47). From here, the flea infiltrated Western Africa and then into the heart
of the continent leading to its widespread presence in Sub-Saharan Africa today
(Joseph et al., 2006, p. 971).
Despite its notoriety, the jigger flea is not regarded as a serious threat to
health (Ugbomoiko, Ofoezie, Heukelbach, 2007, p. 476). Unfortunately this is a
common misconception. Tungiasis results in significant morbidity, manifesting
itself in a number of symptoms such as severe local inflammation,
auto-amputation of digits, deformation and loss of nails, formation of fissures
and ulcers, gangrene and walking difficulties. Secondary infection also poses
considerable risk; many lacking immunisation are vulnerable to tetanus
(Clostridium tetani), often proving fatal. Complaints of insomnia are also not
uncommon due to the intolerable itchiness of the infestation (Muehlen, Feldmeier,
Wilcke, Winter, Heukelbach, 2006, p. 372).
To evaluate the scale of this neglected problem, the study aimed to ascertain
the prevalence of tungiasis in a number of rural settings in the North West
Province of Cameroon. Through a comprehensive, locally administered
questionnaire, we also aimed to identify any risk factors or preventive measures
and assess their impact on this well known, but poorly handled health problem.
Figure 1: Life cycle of Tunga penetrans. (Gordon,
1941, p. 47; Nagy et al., 2007, p. S237)
Materials and Methods
Study Area and Population
This cross sectional study was carried out among townships within the Ndu
subdivision of the Northwest Province of Cameroon, an anglophone region lying
300km from the capital city, Yaounde, and 100 km north of Bamenda (see Figure
2). The population of the Ndu subdivision is 86,322 inhabitants. Agriculture is
the most common occupation and the area is renowned for its large tea
In the rural outskirts of the subdivision, houses are found on large compounds,
which are governed by traditionally elected chiefs or 'Fons'. In general, the
buildings have a very basic structure with dusty, mud floors, no running water
or electricity. Trying to compare
home insurance quotes for buildings like this
is practically impossible. To understand the living conditions better, a
questionnaire regarding each compound was completed. On average, there were 7 people living in
each household, often consisting of three or more familial generations.
Figure 2: Study area
Study Design and Data Collection
This part of Cameroon lies about 800 km north of the equator and experiences
annual dry and wet seasons. This study was conducted for 45 days in July and
August 2008, which fall in the middle of the wet season.
During this time, a total of 1,151 people (occupying a representative sample of
50 randomly selected compounds) were interviewed using a pretested, locally
approved questionnaire and clinically examined for the presence of Tunga
Prior to obtaining any results, a preparatory phase was carried out, in which
draft questionnaires were piloted and all aspects of the study were discussed
and explained at meetings with the Fons of each village. At an individual level,
the study was explained and oral consent was obtained before any data collection
proceeded. Participation in the study was completely voluntary and anonymous.
Interviews were carried out with all those participating in the study. To help
identify potential risk factors for tungiasis, a questionnaire was administered
to evaluate demographic, educational and behavioral variables, as well as any
existing preconceptions or understanding. Parents or guardians were responsible
for answering the questionnaire for any children who were themselves unable to
Every participant was then clinically examined. Although ectopic lesions have
been reported (Heukelbach et al., 2002, p. 215), only the hands and feet were
examined in order to respect individual privacy. The following diagnostic
criteria were considered to be indicative of tungiasis: a circular, white lesion
with a central black dot (4-10mm diameter); a black thickening surrounded by
necrotic tissue; and partially or totally removed fleas leaving a
characteristic, exposed sore in the skin (Ugbomoiko et al., 2007, p. 476). The
number and location of lesions were recorded. In particularly severe cases, a
trainee nurse removed the embedded fleas, administered first aid to prevent
secondary infection and also referred the patient to their nearest medical
centre for tetanus vaccination. A detailed history was taken in these cases in
an effort to identify possible causes of such heavy infestations.
Following submission of an account of its ethical implications, this study was
approved by the Ethics Committee of the Royal Geographical Society. Whilst in
Cameroon, we organised formal meetings and discussed the study at length with
the Fon of each village. The study was explained fully and approved by all nine
local authorities. All individuals remained anonymous and gave oral consent (a
parent or legal guardian consented for children). Assurance was also provided
that results would be confidential.
Written data were entered into the Epi Info software package (version 6.04d;
Center for Disease Control and Prevention, Atlanta, USA), and double-checked
against the original questionnaires. The data were exported to Microsoft Excel
2008 Version 12.0 for analysis.
Fisher’s exact test was applied to determine the significance of difference of
relative frequencies. Use of median and interquartile range data indicated where
results were not normally distributed.
In all, 1,151 individuals from 50 compounds in nine villages were surveyed. Of
these individuals 567 (49%) were male and 584 (51%) were female. In total, 610
were infested with Tunga penetrans, resulting in a point prevalence of 53% (95%
confidence interval, 50%-56%), although 65% had experienced the flea in the past
month. 336 males (59%) and 274 females (47%) were infested, indicating a
significant difference in prevalence between the two sexes (P=0.004).
The median age of interviewees was 13 years (interquartile range 9-33.5 years).
Interestingly, the distribution by age followed a characteristic curve (see
Figure 3). Generally speaking, the young were worst affected. Prevalence dropped
in adults and then increased slightly in the older population (Table 1).
All affected individuals had
lesions on the feet, most of which presented in the periungual region. Across
the whole study, a total of 3103 parasitic lesions were recorded, 2991 (96%) of
which presented on the feet and 112 (4%) on the hands, resulting in a mean
parasite intensity of 5.1 and a median parasite intensity of 2 (interquartile
range 2-5). Males showed a much higher parasite load (median of 3, interquartile
range 1-7 lesions, mean 6.7) than females (median of 2, interquartile range 1-2,
mean 3.1). The maximum number of fleas on an individual was 102 (see Case
Study), and the highest number of parasites experienced at one time was, on
Of those people infested with
Tunga penetrans, 415 (68%) suffered from light infestations (1-4
parasites), 132 (22%) from moderate infestations (5-12) and 63 (10%) from heavy
Prevalence (%) (95% conf. limits)
Infestation appeared to be more
common in those who did not consider tungiasis a disease, but the sample was too
small to be significant (p=0.35). Prevalence in the illiterate (59%) was greater
than in the literate (50%) (p=0.05). Believing not to be a disease, does not
increase the risk of infection (p=0.34).
The most common treatment method,
used by 98% of the interviewees, was physical removal of the flea with a
sharpened stick (augering). 59% would not consider visiting a medical centre to
obtain treatment for tungiasis.
Tunga penetrans has
many common name synonyms, which provides a good indication of its
internationally widespread prevalence (Sachse, Guldbakke, Khachemoune, 2007, p.
11). Given this, epidemiological data for tungiasis in Africa are sparse. A
recent urban study in Cameroon found a high prevalence of tungiasis in the dry
season (49%). In this study, however, inspections were conducted by school
children on one another, resulting in severe intra-observer bias (Njeumi et al.,
2002, p. 178). In our study, the same two members of the team carried out the
macroscopic inspections to avoid this bias. Our study is the first comprehensive
study on tungiasis and the associated morbidity in a representative sample of
has been demonstrated that tungiasis is endemic to this region of Cameroon, and
impacts heavily on the rural and agricultural communities around the town of Ndu.
The parasite inhibits progress and development in the poverty stricken; farmers
and other breadwinners find it more difficult to work and are held back by the
associated morbidity, such as difficulty in walking, persistent itching and
insomnia. From our sample, 16% found the ectoparasitosis “very debilitating”,
and 65% found it “quite debilitating”. Even after physical removal of the flea,
pain is felt for an average of 3.1 days, nevertheless 59% of the study
population appeared to accept tungiasis as part of everyday life and did not
consider visiting a medical centre for treatment to be worthwhile.
The distribution of prevalence by age followed a characteristic curve. It is
perhaps not surprising that the recorded prevalence in children was greater than
in adults since many aspects of the culture, traditions and way of life in this
region place children more at risk. If worn at all, footwear seldom covers the
entire foot; open shoes such as sandals and flip-flops, or indeed damaged shoes,
are the most common footwear. Children are often left to play in the dry, sandy
courtyard, where villagers walk through and spread the eggs of the flea (Muehlen
et al., 2006, p. 378). In addition, children work on the farm from a young age
(the youngest farmer was 9 years old) adding even greater exposure. Adults
become more proficient at detecting and eliminating a gravid female flea as they
gain experience. That is, until they are hindered by the poor eyesight and
reduced flexibility associated with old age. These factors offer an explanation
for the S-shaped age-prevalence curve.
As the flea cannot jump very
high, the host’s skin must be brought close to the ground in order to facilitate
access (Heukelbach, De Oliviera, Hesse, Feldmeier, 2001, p. 268). Therefore, the
majority of lesions occurred on the feet, and to a lesser degree on the hands.
Ectopic occurrences are significantly associated with the number of lesions, and
have been observed most commonly on the elbows, thighs and gluteal region (Heukelbach
et al., 2002, p. 215). Just 4% of the sample population reported having
experienced the flea elsewhere than the hands and feet, and only one person
reported experiencing the flea on their buttocks (see Case Study).
significant difference in prevalence was observed between the sexes, much like a
study in Trinidad (Chadee, 1998, p. 110). This finding, however, has not been
consistent among all studies and appears to vary from one population to another.
Research in Nigeria and Brazil found no statistically significant difference
between the sexes (Ugbomoiko et al., 2007, p. 477; Muehlen et al., 2007, p. 451;
Ugbomoiko, Ariza, Ofoezie, Heukelbach, 2008, p. 4), while De Carvalho et al.
observed a greater prevalence in females than in males (De Carvalho et al.,
2003, p. 34). These data differences are likely to be related to exposure and
environmental factors, rather than differences in susceptibility.
study in North-east Brazil indicated large seasonal variation in prevalence of
Tunga penetrans, which was greatest at the peak of the dry season (Heukelbach et
al., 2005, p. 146). 66% of those questioned said that jigger flea infestation
peaked in the dry season, and most of them (51%) placed this peak in middle of
Our study has shown that tungiasis in Cameroon is a problem stretching beyond
mere nuisance or irritation; it is associated with severe morbidity and is an
issue which needs to be addressed. Health officials, medical doctors, churches,
schools, chiefs and the sufferers themselves must all become involved if we are
to tackle this disease. Numerous other studies have emphasized the need to keep
animals, such as pigs and dogs, from domestic settings by containing them within
an appropriate enclosure.
once the true burden of a disease is known can control measures be properly
implemented. The aim now is to pioneer a low-cost poster-based education
campaign portraying simple interventions to reduce the prevalence and impact of
Tunga penetrans. Recent studies in neighbouring Nigeria (Ugbomoiko et al., 2007,
p. 3) as well as in Brazil (Muehlen et al., 2006, p. 373) found a similar high
prevalence of tungiasis (43% and 51% respectively), and the main associated risk
factors were used in the design of our poster. Based on anecdotal evidence, our
findings and the other studies, the four predominant methods for reducing
tungiasis are (Joseph et al., 2006, p. 970; Njeumi et al., 2002, p. 180):
Wearing closed shoes
Keeping animals contained
Watering the floors within
Maintaining good personal
These improvements will provide an
effective approach, not only to prevent tungiasis, but also other diseases
associated with poverty (Ugbomoiko et al., 2007, p. 479). More
drastic interventions have been shown to improve the lives of tungiasis
sufferers, such as concrete floors (Muehlen et al., 2006, p. 375;
Ugbomoiko et al., 2007, p. 5),
administering antibiotics, providing shoes (Joseph
et al., 2006, p. 970)
and also applying insecticide spray (Pilger
et al., 2008, p. 2).
Anecdotal evidence suggests that in rural villages like these, new shoes are
traditionally only worn on special occasions. Providing shoes therefore would
only be successful as an intervention if the shoes were worn regularly and not
solely reserved for such occasions.
Tungiasis has been shown to be a
problem for poor rural populations in numerous developing countries in South
America, the Caribbean and Sub-Saharan Africa. Despite its associated morbidity
and the growing awareness of the disease, however, tungiasis is not recognised
on a local or international level as a serious health issue. Educating people
about the risk factors and potential causes is paramount in addressing the
problem. Raising awareness through a well structured poster campaign will help
reduce the impact of this flea on exposed communities.
This study was supported by the
David Cross Award of the Royal Geographical Society (with IBG). We would like to
thank the following people for their invaluable assistance: Charlotte Collins,
Brenda Cross, Hans Dobson, Robert Lasenby, Graham Matthews, Emmanuel Ngungoh,
Oscar Swift, Jane Zuckerman. We are also grateful to the kind people of the Ndu
subdivision who were so willing to welcome and embrace the purpose of this
1. Chadee, D.D. (1998). Tungiasis among five communities in south-western
Trinidad, West Indies. Annals of Tropical Medicine and Parasitology. 92 (1),
2. De Carvalho, R.W., De Almeida, A.B., Barbosa-Silva, S.C, Amorim, M, Ribeiro,
P.C., Serra-Freire, N.M. (2003). The Patterns of Tungiasis in Araruama Township,
State of Rio de Janeiro, Brazil. Mem Inst Oswaldo Cruz. 98 (1), 31-36.
3. Feldmeier, H., Eisele, M., Van Marck, E., Mehlhorn, H., Ribeiro, R.,
Heukelbach, J. (2004). Investigations on the biology, epidemiology, pathology
and control of Tunga penetrans in Brazil: IV. Clinical and histopathology.
Parasitol Res. 94, 275–282.
4. Franck, S., Feldmeier H., Heukelbach, J. (2003). Tungiasis: more than an
exotic nuisance. Travel Medicine and Infectious Disease. 1, 159-166.
5. Gordon, R.M. (1941). The Jigger Flea. The Lancet. 2, 47-49.
6. Heukelbach, J., De Oliviera F.A.S., Hesse, G., Feldmeier, H. (2001).
Tungiasis: a neglected health problem of poor communities. Travel Medicine and
International Health. 6 (4), 267-272.
7. Heukelbach, J., Wilcke, T., Eisele, M., Feldmeier, H. (2002). Ectopic
Localisation of Tungiasis. Am. J. Trop. Med. Hyg. 67 (2), 214-216
8. Heukelbach, J., Wilcke, T., Harms, G., Feldmeier, H. (2005). Seasonal
Variation of Tungaisis in an Endemic Community. Am. J. Trop. Med. Hyg. 72 (2),
9. Joseph, J.K., Bazile, J., Mutter, J., Shin, S., Ruddle, A., Ivers, L., Lyon,
E., Famer, P. (2006). Tungiasis in rural Haiti: a community-based response.
Transactions of the Royal Society of Tropical Medicine and Hygiene. 100,
10. Muehlen, M., Feldmeier, H., Wilcke, T., Winter, B,. Heukelback, J. (2006).
Identifying risk factors for tungiasis and heavy infestation in a resource-poor
community in northeast Brazil. Transactions of the Royal Society of Tropical
Medicine and Hygiene. 100, 371-380.
11. Muehlen, M., Heukelbach, J., Wilcke, T., Winter, B., Mehlhorn, H., Feldmeier,
H. (2003). Investigations on the biology, epidemiology, pathology and control of
Tunga penetrans in Brazil: II. Prevalence, parasite load and topographic
distribution of lesions in the population of a traditional ﬁshing village.
Parasitol Res. 90, 449-455.
12. Nagy N., Abari E., D’Haese J., Calheiros C., Heukelbach J., Mencke N.,
Feldmeier H., Mehlhorn H. (2007). Investigations on the life cycle and
morphology of Tunga penetrans in Brazil. Parasitol Res. 101, S233–S242.
13. Njeumi F., Nsangou C., Ndjend A.G., Koga, Ostanello, F., Pampiglione, S.
(2002). Tunga penetrans au Cameroun. Revue M√ƒ¬©d V√ƒ¬©t. 153 (3) 176–180.
14. Pilger, D., Schwalfenberg, S., Heukelbach, J., Witt, L., Mencke, N., Khakban,
A., Feldmeier, H. (2008). Controlling Tungiasis in an Impoverished Community: An
Intervention Study PLoS Negl Trop Dis. 2 (10), e324.
15. Sachse, M.M., Guldbakke, K.K., Khachemoune, A. (2007). Tunga penetrans: a
stowaway from around the world. JEADV. 21, 11-16.
16. Ugbomoiko, U.S., Ariza, L., Ofoezie, I.E., Heukelbach, J. (2007). Risk
Factors for Tungiasis in Nigeria: Identification of Targets for Effective
Intervention. PLoS Negl Trop Dis. 1 (3), e87.
17. Ugbomoiko, U.S., Ofoezie, I.E., Heukelbach, J. (2007). Tungiasis: high
prevalence, parasite load, and morbidity in a rural community in Lagos State,
Nigeria. International Journal of Dermatology. 46, 475-481.