INTRODUCTION
Mycetoma is a chronic granulomatous disease of the cutaneous and subcutaneous
tissue, which sometimes involves bones, muscle and neighboring organs.
The infection caused by actinomycetes or by true fungi. Clinically the
disease is characterized by indolent, deforming, swollen lesions and sinuses
involving cutaneous and subcutaneous tissue, fascia and bones that usually
occurring on foot or hand. For the first time Gill described the disease
in the Madura distinct of India in 1842. On the other hand in 1813, Pinoy
described the mycetoma produced by aerobic bacteria that belong to the
actinomycete group (Saag et al., 2000).
Generally this agent present in soil or on vegetable as saprophytes.
The disease usually occurs in journey prone part of body months or years
after the relevant trauma (Hay, 1996; Fahal and Hassan, 1992). At least
10 geophilic actinomycects are reported to cause actinomycetoma but many
more similar organisms are known without pathogenic significance (Ahmad
et al., 2003; Fletcher et al., 2001).
The single most common site of infection is foot and the symptoms generally
appear after a long incubation period (Maiti and Halder, 1998). The disease
advances slowly per months or years, typically with minimal pain. When
pain is experienced, it is usually due to secondary infections or bones
involvement. Although it is rarely fatal, mycetoma causes deformities
and potential disability at the advance stage (Saag et al., 2000;
Hay, 1996).
Generally in the regions where the disease is endemic, throng trees such as
acacia are abundant. The wounds caused by the thorns may facilitate the entry
of the soil-borne organisms, or the causative agents may grow saprophytically
on the thorns and enter the body as the thorn penetrates the tissue. Mycetoma
has been divided to two groups Eumycetoma and Actinomycetoma. Eumycetoma can
be produced by a variety of fungi such as, Acremonium sp., Fusarium
sp., Pseudoallescheria boydii, Exophiala jeanselmei, Madurellya
grisea, Madurella mycetomatis, however actinomycetoma are mainly
produced by bacteria of 4 genera Nocardia, Actinomadura, Streptomyces
and Actinomycete (Hay, 1996; Gumaa, 1994).
It should be mentioned that the geographic distribution of the pathogenic
agents determine by the annual rainfall, for example in North of Iran
with rainy and humid status, the prevalent agent is Actinomycectes and
Nocardia which leads to actinomycetoma, so in a retrospective study we
decided to determine the prevalence of mycetoma and its causative agents
in different parts of Iran (Zaini et al., 1999).
MATERIALS AND METHODS
The 62 cases of mycetoma which were clinically and microbiologically
confirmed mostly in Medical Mycology Department, School of Public Health,
Tehran University between 1972 that the first case of mycetoma has been
reported and 2005 were studied. The records included general information
such as date of diagnosis, age, sex, occupation, resident, initial site
of lesion and duration of the disease.
The diagnosis of all cases was established by microscopic findings and
culturing of the specimens included visible granules and discharge collections
that were processed in multiple sets in sabouraud,s dextrose agar media
with and without chloromphenicol and Brain Heart Infusion agar at 37 °C
incubation. At last isolates were identified by studying colony morphology,
fungal morphology and their conidiogenesis and Actinomycetes were
diagnosed by use of casein, xanthine tyrosine and urea tests.
The initial sites of lesions were classified into two parts; pedal parts
included sole, ankle, leg, knee and toe and the extra pedal areas included
arm, fore arm, elbow, palm, finger, wrist and buttock. According to nature
of job cases were divided to farmer, other manual and sedentary workers.
The injuries were classified in five categories that pointed injuries
such as pricking that had special importance in the epidemiology of mycetoma
and the other included cuts, operated injuries, scratch and war injuries.
RESULTS
According to this study among 62 cases of mycetoma 20 cases (30.65%)
were Eumycetoma and 42 cases (69.35%) were Actinomycetoma. The distribution
of causal agents was as follows: Pseudoallescheria boydii, (n =
8), Madurella mycetomatis (n = 2), Aspergillus flavus (n
= 1), Aspergillus fumigatus (n = 1), Exophiala jeanselmei
(n = 1), Fusarium spp. (n = 1), Pcilomyces spp. (n = 1)
and unidentified eumycetoma agents (n = 5).
Actinomadura madurae (n = 11), Nocardia asteroids (n =
9), N. caviae (N. otitidiscaviarum) (n = 6), N. brasiliensis
(n = 1), Nocardia spp. (n = 5), Actionmyces Israeli (n
= 1), Streptomyces somaliensis (n = 1), S. spp. (n = 1)
and unidentified actinomycetoma agents (n = 7).
In this survey the earliest age of onset was 18 and the latest 65. The
most prevalence of disease was seen in 41-50 age groups with 15(24.2%)
frequency. It should be mentioned that among the cases, 41(64.5%) were
male and 21(35.5%) were female with a risk about 2:1. Involvement of men
is more common because of their job and outdoor activity, but there wasn’t
a significant differences between sex groups (p > 0.05). More information
about distribution of mycetoma base on age was shown in Table
1.
| Table 1: |
Incidence of mycetoma in relation to age and sex |
 |
| Table 2: |
Risk factor-related differences of mycetoma incidences in
pedal and extra pedal parts of the body |
 |
Localization of the infection based on site of lesion were; pedal (n=49) included
sole (n = 34), ankle (n = 5), leg (n = 5), knee (n = 3) and toe (n = 2). Extra
pedal (n = 13) included palm (n = 3), wrist (n = 3), buttock (n = 2), arm (n
= 2), fore arm (n = 1), elbow (n = 1) and finger (n = 1).
The single most common site of infection is foot but generally hand and other
limbs can infected. In our study the most infected limb is foot specially palm
with 54.4% of infected areas and other area with less frequency such as fore
arm, elbow and finger. The incidence of mycetoma in pedal was almost fore times
higher than that of extra pedal areas (p = 0.01). This might be the result of
high occupational risk of trauma and soil contact especially in agricultural
workers.
The result shows that farmers with 28 (45.2%) are at greater occupation
risk of mycetoma. The difference (p < 0.01) between farmers with other
occupation might be the result of their occupational in farm that they
have a high risk for prinking injuries by thorns and plants. The more
information were shown in Table 2 include etiology agent,
job and anatomical site of lesion.
A history of previous injury was noticed in more than 50% (n = 35) of
them, in some barefoot walking in soil and farm was frequent and in some
others there was no history of proven trauma. Prinking injuries (n = 29)
comprised of puncture with a thorn, wooden spicule, plant fiber or needle.
The incidence of mycetoma associated with pricking was significantly higher
(p < 0.01). Other injuries included war injuries (n = 2), cut (n =
1), operated injury (n = 1) and scratch (n = 1). Granules were detected
in 53 cases and most of them were white in color and soft. In 12 cases
direct examination has been negative but the agents were isolated in culture.
In two cases partially acid-fast branching filaments were seen in stain
and branching filaments in the KOH preparations, but results of culture
were negative and suspected to be due to Nocardia species. In one
case any granule was not seen neither macroscopically nor in histological
sections, but Gram positive, acid-fast branching filament was observed
in pus smear, nor in culture Nocardia asteroides was isolated.
DISCUSSION
We were retrospectively compared the overall prevalence of mycetoma and
its infective agent in Iran during 33 past years. In our study we have
considered not only the age, sex and job but also the site of infection.
We studied 62 cases of mycetoma retrospectively since 1972 to 2005 in
Iran. Among 62 cases 42 (30.65%) was actinomycotic mycetoma and 20 (69.35%)
were related to eumycotic mycetoma, therefore according to our findings
actinomycetoma is significantly more prevalent in Iran (p < 0.05) which
is also detected in the most reports and the ratio of actinomycetoma to
eumycetoma is 3:1 (Dieng et al., 2005; Daoud et al., 2005).
Most of present cases have belonged to rainy and humid status in north
of Iran. Dieng et al. (2003) reported 130 cases of mycetoma in
Senegal from 1983 to 2000. Among their study they found that the geographical
distribution of pathogenic agents was determined by the annual rainfall.
Mycetoma is endemic around the tropic of cancer, 15 ° Souths and 30
° North of the equator, in tropical, subtropical and temperate regions.
Mexico, Venezuela, India, Pakistan, Senegal and Somalia have the highest
incidence of disease wide. The United States, Asia and other Latin American
countries have reported cases less frequently (Saag et al., 2000;
Hay, 1996). Generally environmental condition such as the temperature
and humidity of the area must be suitable for the growth of the pathogenic
organisms in the soil (Saag et al., 2000). Agents which caused
mycetoma are present in soil or on vegetable as saprophytes (Saag et
al., 2000; Hay, 1996).
In present study the most prevalent infective agent is Actinomadura
madurae (n = 11) that is like as the reports from Tunisia, Algeria
and Morocco (Daoud et al., 2005). Some investigators determined
the etiologic agents of mycetoma in Iran (Zaini et al., 1999; Hashemi
and Gramishoar, 2001). The results of their survey provided information
for the first time on the prevalence of etiologic agents of mycetoma in
the soil and plants of Iran. They found that especially north of Iran
based on rainy and humid condition actinomycetoma is more common.
In this disease age has been considered as an important factor but in
our study there wasn’t significant differences between age groups (p >
0.05) and the peak age for infection was between 40 and 50 years old.
This matches with data from medical literature setting the age of onset
as being the active period of life about 40 years old (Daoud et al.,
2005; Dieng et al., 2005, 2003; Khatri et al., 2002).
It should be mentioned that among the 62 cases which reported 41 cases
(64.5%) were male and 21 cases (33.9%) were female. Involvement of men
is more common and it is related to their job and their activity which
is out door, but there wasn’t a significant difference between sex groups.
We have tested our data and found that there is no correlation (Spearman
correlation) between sex groups (p > 0.05) that is similar to Daoud
et al. (2005). Maiti et al. (2002) investigations about
mycetoma in exposed and no exposed parts of body show that the (male/female)
cases rations of two parts of body is also different (Maiti and Haldar,
1998).
We have considered that occupational risk in our groups and our results
show that farmers are at greater occupation risk of mycetoma. Among the
cases 45.2% was farmers we can interpret these data because they have
a high risk of injuries that permit infection with saprophytic agents.
It should be considered that the trauma is not the only factor for the
outcome of the disease but also the viability of the organism and local
wound conditions can also modify the outcome (Maiti and Haldar, 1998).
Epidemiological information generated from retrospective analysis of
212 mycetoma cases attending Calcutta school of tropical medicine during
1986 to 1997 revealed that mycetoma which occurred on covered parts of
body significantly differed from mycetoma occurring on exposed parts (Maiti
and Haldar , 1998; Maiti et al., 2002).
In present study the most common area for infection was pedal mycetoma
because it has the most contact with thorns and plants in out door due
to some habits such as barefoot walking or agricultural activity. Fungal
and bacterial agents are saprophytes in soil or plants and the inoculation
of the agent is generally was done by soiled tools (Hashemi and Gramishoar,
2001; Akhtar ands Latief, 1999).
Finally it should be mentioned that mycetoma are rare in Iran and only
appear sporadically. Since the first Iranian case reported in 1972, only
62 cases were reported up to 2005 almost 2 cases per year.
Subscribe Today
