Panoramic Record of Rat-tailed Maggot Incidence and its Burden on the African Community

By Fidelis Achenjang*, Vincent Fondong*, Anthony Asong* & John Mbizoh* 

Introduction:

Africa remains a hotbed of some exotic diseases that have caught the attention of many and thus have been researched and reported through practices and concerns of ‘tropical medicine’ in Africa: check Syphilis in Colonial Africa… the Social Construction of an Epidemic or Health & Hegemony in Colonial Africa (Vaughan, 1991). These diseases include the sexually transmitted HIV-AIDS, sickle cell disorder, malaria, tuberculosis and sleeping sickness or the ‘tsetse fly-disease’. One debilitating illness that seems to be rampant in Africa but less reported is a kind of myiasis caused by the rat-tailed maggots (RTMs) known under various names/translations as asticot à queue-de-rat (French);  Ratte-Geschwanzte Maden (German); Larvae Unite Ratto (Italian); Gusanos Atados Rata (Spanish) and Rat Van de Steel Verwijderde Maden (Dutch). 

Myiasis and RTM as Causal Agents

Myiasis is an illness caused by the invasion of animal skin and tissue by live micro-organisms. The rudimentary nature of public health infrastructure in most of Africa in terms of research and diagnostic facilities and the skeptical attitude of medics makes it difficult for sufficient information to be available about myiasis or RTMs. As a result, stakeholders find it hard if not impossible to document and report disease burden estimates arising from the activity of rat-tailed maggots in the continent.

Getting the public involved in the health care system based on public evaluations, examinations and experiences is an excellent initiative that can transform the current politics of caring (healthcare system) into one that actually works for enclave and resourced-poor areas of Africa. Most of the areas are densely populated communities in a rural setting having just a handful of functional health centers, hospitals and a strong cultural belief; thus making the road to health success pretty worrisome.

 Looking back at a public health timeline in Africa we find a horizon littered by many milestones marking how far we have come. This paper attempts to sensitize public awareness on a menace that might well have found a home in sub Saharan Africa which might just as well bring us to one such milestone given our interest in, present knowledge of and provisional data on, intestinal myiasis caused by RTMs (www.maggotresource.com)

Documenting diseases, give rise to a publication, expected to be a product that stays around for a long time. Thus it could constitute a reliable informative resource for our healthcare system comprising data, healthcare trends and a sensible approach on how to live life without being miserable. A key component of the United Nations Development Program, UNDP country-level measure of social welfare termed Human Development Index, HDI, is health inequality with data usually retrieved from the World Health Organization’s Mortality Database.

 For the first time we provide a panoramic report on myiasis in Africa, a complicated disease condition caused by RTM gastro-intestinal infestation. It is a not-so-silent killer, more common and more devastating than most people and health care workers know and believe. In most of Africa, it is generally referred to as caterpillar especially when its victims are children. The terminology is however a misnomer because biologists know maggots represent (house)fly larvae and caterpillars refer to moth or butterfly larvae! Also, biologists distinguish simple (egg => nymph => adult) and complete (egg => larvae => pupae => adult) metamorphosis judging from the number of stages and the fact that the worm-like larvae can live in a different environment and constitute the main pest.

 Sometime about mid 2006, South Africans were seized by fear of a RTM plague when news reports claimed an assortment of Cape Town citizens found huge numbers of RTM popping out of basins, toilets and water taps all across the city in a random fashion (Reuters, 2006). This report was however challenged by findings of the Ministry and Department of Water Affairs & Forestry, DWAF. In a media release, DWAF wrote that of the handful of houses that actually had cases of maggots, ‘no evidence could be found that these creatures actually came from a tap’. Besides, DWAF insisted, a small filter designed to take out foreign material in water meters was found to be perfectly clean upon inspection whereas had the RTM story been accurate, it should have been clogged with worms and maggots. Also DWAF noted that initial tests found that their drinking water was never contaminated with organic matter, which matter was critical for the existence of the alleged maggots.  DWAF further concluded that, whereas RTM live in water where anaerobic conditions exist and organic matter is in abundance; the alleged maggots could not be found in treated water of a municipal distribution system. On the other hand, DWAF agreed that some other areas where these rat-tailed maggots thrive included debris and equipment behind walls, open septic tanks, unkempt yards and stagnant waters (Media Release, 2006).

 What Are Rat-tailed Maggots:

Rat-tailed maggots (RTMs) are generally fish (worm)-like creamy larval stages of certain insect families like the pine saw and drone flies (Whish-Wilson, 2000). Additionally lacking a distinct head, they present cylindrical bodies about 2.5 cm or an inch long, with a non retractable siphon-like tail of variable length, which may be used for a breathing tube (stigmata). These maggots predominantly live in wet situations, frequently in liquid manures, drainage ditches, sewage piles but also in other stagnant and polluted water environment (afo’o). Their adult fly stages resemble the honey-bee in action and appearance but have only a pair of wings. They are different from tumbu fly larvae that cause furuncular myiasis of the breast (BioMed Central, 2004) 

The larva or maggot generally moves or creeps from wet to drier habitats to pupate and subsequently metamorphose into the adult fly after adequately feeding on the abundant bacteria in the putrid pools. It is during such periods that the maggots may become a public nuisance, crawling into walk ways, buildings and finding access into feed troughs, drinking water, palm juice and exposed food. Subsequently these RTMs may find themselves deep in the gastrointestinal tract by ingestion of contaminated food or drink, where they feed on host’s tissue, body fluids and ingested food, while co-harboring as obligate parasites that cannot develop any further in their evolutionary cycle. The eggs, although very rarely seen, have been described as elongate-oval and usually less than 1 mm long; found in liquid manure intended for use around edible plants, as in a garden. The adult flies or RTMs occur throughout much of the world (Hira, 1977; Whish-Wilson, 2000), especially where there is active livestock (cattle, sheep, goat) production.  Their distribution has been reported in India, North America, Central Europe, New Zealand, Australia and now Africa. Inter- and transnational travel is partly responsible for the world wide distribution of the various forms of infections. We can suppose or conjecture that RTMs are transmitted through passengers’ foodstuff and their contaminated luggage as viable eggs or actual larval forms.

Real Threat or Cry for Attention:

Living with gastric myiasis can be stressful enough for patients of all age groups and socio-economic positions, firstly because of the difficulty and inaccuracy of orthodox medical diagnosis and because the disease may cause complications that make life nerve-racking due to possible myiasis neuropathy (nerve disorder). Thus good education about the disease can help patients and caregivers cope with the challenges and difficult situation, contribute to minimizing or diminishing suffering and encourage diagnosis and healing without preconceptions.

The empiricism, curiosity and interests of early tropical medicine depicted through assorted photographs, diary entries etc. catalogues ‘tropical horrors’ or exotic disease cases on Africans for future study, understanding and classification on the basis of the trio – agent, host and environment or climate, diet, housing, geography, customs or traditions. The seemingly opposing forces, culture or African traditional practices and nature or disease pathogen; in our opinion have slowed the acceptance of rat-tailed maggot incidence as causal factors in (myiasis) disease. Additionally, Africans hitherto regarded as a reservoir of disease, now considered tamed, there is hardly an aggressive need to “prevent the spread of disease”. Of course, this notion is blatantly wrong, because for all we know, transnational travel today and the world as a global village both lend credence to the fact that we are all in the boat together. There can be no meaning to such slogans like ‘health for all by 2010’ if steps to ‘prevent the spread of disease’ are underestimated.

As we explain in this paper, gastric myiasis can be responsible for severe abdominal discomfort. The enemy, RTM, hidden in the victim’s gut, and therefore unable to continue its natural metamorphosis cycle, cannot develop into the adult fly. From this invasive endoparasitic lodge, it is capable of eluding orthodox medical detection, diagnosis and treatment. To this end, gastric myiasis generally considered as exceptional (Abkari et al., 1998) and its agents, the RTM, remain a public health issue even if the zoonosis is not recognized as a classified reportable public health disease.

The critical concern whether RTM or their adult fly forms constitute disease vectors or agents in animals cannot be adequately addressed presently because the “fly” life cycle remains fluid, unusual, little studied and understood. Some believe rat-tailed maggots are very rarely pests and do not pose a threat to man or livestock. We disagree seriously with this assertion given the many cases and consequences of enteric pseudomyiasis and intestinal infestation by rat-tailed larvae documented (Stiles et al., 1953; Achenjang et al., 2003).

There is a report of a 13-year-old boy from West Bengal's Burdwan district who had fully grown flies, as medics described the parasites, emerging out of his genitals for more than a fortnight (penile myiasis?). Following a cystoscopy to clear the boy's urinary tract, a couple more flies still oozed out of his penis. This is a rare and bizarre case of myiasis where whole flies emerge out of a human body. It is sad that when the boy, who initially felt pain in his abdomen for a couple of weeks, told his parents he saw flies intermittently coming out of his penis, the parents did not believe him. Later his skeptical medics and parents were stunned as they evaluated and treated the rare case (IANS, 2003). 

Humans Living with Illegals & The Multiple Hats of Myiasis:

 The broad range invasion of animal skin and soft tissue by life microbes, including intestinal parasitism or fly larvae on humans, is not a strange scientific phenomenon. It is described as myiasis (Hira, 1977; Aguilera et al., 1999;  Mutaj,  2000) and occurs more frequently in the form of ecto-parasitism in sheep, goats, cattle, cats & dogs  affecting economic, health & reproductive performance & leading to great losses in meat, hide & milk production as well as quality (Mario et al., 1993, Pruett,  1999).  

Normal ecto-parasitic infestation of animals (including rodents and human hosts) is usually determined by visual or self-examination by patients and caregivers. Examples of such broad range infestation include body, head, clothes, pubic or crab lice; ticks; mites; midges; sand fleas or jiggers. This very familiar form referred to as ecto-parasitism, may involve the illegal attached pathogens, burrowing into the skin of the soles of feet, toenails or fingernails and causing itchy lumps, scabies or swellings and variable irritations and discharge of exudates. As an aside, those who attended school in dust-laden regions of Africa, will greatly appreciate and understand ecto-parasitism per se and the resultant zoonotic diseases in some cases (agwo’o lelo’o).

In a further classification, other exotic forms of myiasis are determined according to the location of the fly maggot or larvae. Notably, myiasis in the form of dermal or cutaneous infection by fly maggots have been reported and described around various anatomical cavities or body areas like the eye (orbital myiasis), ear (auricular myiasis), genitals (vaginal-myiasis), mouth (oral myiasis), nose (nasal myiasis), anus (rectal myiasis), breast (furuncular myiasis), penis (penile myiasis), cheeks, buttocks, forearms and legs. Parasites that succeed in penetrating further through some cavities may cause the rare exotic and novel urinary tract and gastro-intestinal myiasis reported sporadically from different countries and briefly mentioned in some medical and parasitological textbooks (Stiles et al., 1953; Aguilera A. et al., 1999; Cheng C. T., 1973). The clinical picture usually depends on the maggot species, site of infestation and the severity of infestation. Control of the pests requires fundamental insecticidal chemicals and hygiene practices. These topics and more will be discussed in a subsequent paper.

Making Sense of Gastric Food-borne Myiasis:

Knowledge of the incidence, prevalence and distribution of the new face of human gastro-intestinal myiasis caused by “imprisoned yet free” rat-tailed larvae is abysmal. As stated earlier on, we conjecture or presume that direct human ingestion of the eggs or other immature stages like the larvae, through contaminated drinks or foodstuffs would be the source of intestinal myiasis (Chigusa, 2000; North, 1987; Achenjang et al., 2003). Using the services of the United States Department of Agriculture, USDA, we have identified two species of RTMs in Cameroon, collected from polluted habitats and marshy areas, specifically from rotten or decaying banana stems and raffia palm trees/trunks and later grown in the laboratory to adult flies. It should be recalled that, because of the dearth of scientific literature on RTM, many synonyms and nicknames like critter, tubifera, bugs, long tailed mouse, sheep or wool maggot, sewage fly larvae or new world bot fly are used interchangeably in reference to rat-tailed maggots, RTM. 

Capsule Endoscopy, Better than a Palliative Answer:

The precise location of endoparasitic RTMs in humans/animals is not clear principally because their mode of transmission remains also fluid. However we believe they may be found in the intestines or better still, at the opposite ends (stomach and rectum) of the digestive tract.  Cases are known of expulsion of RTM less frequently through vomits, and more frequently through excrement after administration of a traditional enema concoction. Thus harbored RTM may easily be revealed through colonoscopy and upper gastrointestinal endoscopy. There is no literature report as yet for this revelatory means.  If the RTM are found in the greater part of the small intestines (ileum), then visualizing them in that area so as to enable appropriate diagnosis is difficult. Additionally, x-rays may not be informative and exploratory surgery may not be advisable.

 We are convinced; the new diagnostic tool that has been described and termed (video) capsule endoscopy may fill the revelatory gap (Sidhu G. et al., 2006). In this case, following a 2-hour fast the patient is given a “special pill” that carries a sophisticated disposable digital camera that can produce thousands of high resolution images as the capsule pill travels through the digestive tract. The images subsequently captured are instantly relayed through sensors, recorders and subsequently downloaded into a computer and transformed into a digital movie for expert medical appreciation. The capsule is passed out in the stool following the 8-10 hour examination.

 
We believe, eventually, molecular biology tools will be used to study the taxonomy, phylogenesis, identification, immuno-diagnosis and vaccination/control strategies for RTM. It would be possible to also study the surface features of various RTM types to obtain useful taxonomic information using scanning electron microscopy (SEM). The prohibitive costs of both techniques are certainly slowing their arrival and use in all of Africa.

Dataless Reminiscences On Rat-tailed Maggot Infestation in Cameroon:

Incidentally, maggot specimens collected in Cameroon from the gastro-intestinal tract (GIT) of children and teenagers remain unidentified because of the lack of their adult forms. The maggots recovered from the feces of patients who had a long history of stomach pains, we recall, were obtained by involuntary expulsion upon administration of traditional enema concoction. The patients frequently complained of abdominal pains and displayed various symptoms such as nausea, vomiting, diarrhea and loss of appetite. Symptoms of RTM gastro-intestinal infestation have to date, not been diagnosed by orthodox medicine; even then RTM disease patients have frequently been treated at clinics and hospitals, following presumptive laboratory diagnosis for ameba infestation and sometimes typhoid fever.  Although most patients we know lived in a rural environment, there was not much gleaned from either the medical records or the patients to suggest that they had a low standard of hygiene. 

 The interrelation of age, body region, and sex with RTM infestation is still to be studied. On the other hand, the constraint and burden on the education of the diseased children and teenagers seemed to be very clear (Achenjang et al., 2003. Once again, inequalities in education constitute another of three key components of the UNDP Human Development Index, HDI.  

Gastrointestinal myiasis appears to recur, is severe in some individuals although benign and/or symptom less in others. The precise role of the larvae, the nature of its life cycle and other factors like enzyme levels secreted remain to be elucidated. We think the trapped intestinal RTM obtain nourishment from the exudates they induce internally. Thus we can safely suspect RTMs may find application in their use in biotherapy or wound and skeletal debridement thanks to the levels and nature of their protein exudates. Over the centuries, live maggots have been used therapeutically to clean and manage wounds/sores and to eat up tissue/flesh to expose skulls and bones for identification and museum display. It would not be surprising if sterile RTMs eventually replace ordinary fly maggots and leeches as medicinal organisms of choice in combating bad odor, pain and more.

 Given the cumbersome nature and complications in the control of human gastric-myiasis, a health education strategy is urgently needed to enlighten different communities about the existence, mode of acquisition and transmission of RTMs. Although not obviously linked to environmental sanitation, such a health education strategy would call for improved personal hygiene and watering of school classrooms and surroundings; prompt disposal of any pet and animal wastes and less (human) fraternization with pets or domestic animals. Also recommended would be conditions that discourage an enabling environment for the growth, oviposition and invasion of human skin by the maggots through exposure of tender skin areas and extra care adopted to not leave exposed foodstuffs unattended, washing fruits and vegetables prior to consumption and not sleeping outdoors during the daytime when the adult flies are most active and likely to oviposit in body orifices, exposed wounds and to exposed foodstuffs like vegetables and fruits.

A preliminary survey of key tribes  and ethnic groups in the Northwest, Southwest, Littoral, Centre and West Provinces, revealed that RTM are well known only to Lebialem (nweh), Ndian (bafaw) and Menoua (bamileke) divisions.  Does this imply that gastric myiasis will be endemic only to these areas that constitute regions where palm oil is processed?  The absence of RTM presence and knowledge in the grassfields of Bamenda, among the bakwerris and in hot and humid banyang land is mind boggling.  There are no published reports of RTM in Cameroon. However, many world-wide reports of intestinal myiasis due to ordinary fly and RTM exist (Mutaj, R. et al. 2000; Whish-Wilson, P. B. 2000; Aguilera A. et al.,1999;  Hira P. R. 1977).

 Take-home Message:

Although the biggest killers of the beleaguered people of Africa, are malaria, diarrhea, sleeping sickness (agwo’o lelo’o), malnutrition, respiratory infections (tuberculosis), and AIDS/HIV, the unusual presence of intestinal myiasis in thousands children/teenagers and counting, including some cases in adults continues to baffle experts in parasitology and medicine. The African geography and environment are hostile enough. Their combination with political prostitution, economic decline, poverty, hunger, obscure and neglected diseases is rarely seen in one place at one time elsewhere in the world. May the gods of Africa listen to the pleas and cries of her children!!!

We need to continue making para-clinical examinations and collecting epidemiologic data, assessing beliefs and attitudes of the population towards the disease and searching for therapeutic solutions.  We can expect that negotiation of translocal knowledge and health development would be a panacea for containing this exotic, unpleasant and stubborn affliction/infestation in Africa. 

References:

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*  www.maggotresource.com  is an evolving compendium-database-portal cum resource on the world of rat-tailed maggots and other larval infestation/diversity. The editors gladly request and look forward to, your contributions, suggestions, comments, novel materials and resources via email at rattailedlarvae@maggotresource.com or pav87central@yahoo.com