Introduction

Leishmaniasis is endemic in 88 countries through out Africa, Asia, Europe, and North and South America. There are estimated 12 million cases world wide, with 1.5-2 million new cases each year (WHO, 2006). The parasite enters the human host with the bite of the sand fly and is pulled into macrophages by ingestion. Leishmania parasites are able to survive in acidic environment of the lysosome and become amastigote forms which cause disease in humans and affects cellular immunity (Talari, 2006). Parasite begins as an erythromatous papule at the site of sand fly bite on exposed parts of the body. Cutaneous leishmaniasis (CL) is still considered an important health problem in many parts of the world, especially the Mediterranean region, and almost all countries of the Middle East, including Iran (Talari, 2006; Momeni, 1994). In Iran the prevalence of disease is high in some provinces, including Isfahan (Salimi, 2000), Shiraz (Moaadab et al., 1993), Khorasan (Javadian et al., 1967), Khouzestan and Kerman (Nadim, 1971).

Although this disease dose not cause mortality, but a prolonged period of lesions, great expense of treatment , and side effects of available drugs, it has created many problems (Momeni, 1994; Talari, 2006). Diagnosis of CL is important for initiating appropriate clinical management and treatment of this disease. Microscopy may be the simplest method of achieving but diagnosis by cultivation has advantages. This study was performed in order to the abundance and characteristics of cutaneous leishmaniasis in patients referring to the Department of Parasitology, Pasteur Institute of Iran (IPI) during 2003-2006.

Material and methods

Patients and samples

Direct smear

Culture method

Results

The results indicated the amastigotes in skin smears and the frequency of CL in 322 patients was 45.3% (146 positive cases). Infections with CL were observed in 57.7% (83) males and 43.1% (63) females. Although, the highest rates (%28.8) of infection were recoded in both genders in 21-30 years age group, the lowest rates (8.9%) were observed in the age group of >50 years (Fig. 1).

Figure 1

Figure 1: Frequency of cutaneous leishmaniasis by age and gender

Single lesions were observed in 45% of patients, appearing a round popular plaque with a diameter of 4-80 mm. In addition, double lesions were shown in only 23% of patients, however 32% represented multiple lesions between 3-7 (Fig. 2)

Figure 2

Figure 2: Percentage frequency of CL lesions in patients

Detailed location of lesions was shown in Table 1. Hand and arm was the most commonly affected sites (48.6%).

Figure 3

Table 1: Lesions location of CL in patients referred to IPI

All samples were scraped and aspirated from the edges of skin lesions and cultured in liquid phase of NNN media. After regular examination of the overlay, 146 isolates were grown in the culture media (Fig. 3).

Figure 4

Figure 3: Frequency of cutaneous leishmaniasis according to methods of diagnosis

Residence, workplace, travel history of patients were important data for determining the location where the infections might have taken place. The highest infection rate (19.9 %) was recorded in patients who are traveling or living in Isfahan and Kashan .Lowest rate (3.4 %) was recorded in patients living in Ghom, Fars, and Khouzestan provinces (Table 2).

Figure 5

Table 2: Frequency of CL by place of residence and travel history

Leishmania parasite was isolated from the unhealed lesions of a woman who had lesion in her face within period of about 2.5 years. She lived in Sabzevar (Khorasan province), where the CL is endemic (Fig. 4).

Figure 6

Figure 4: Unhealed CL lesion from a patient from Khorasan

Discussion

In this study frequency of cutaneous leishmaniasis was 45.3 % by culture method. Depending on the findings of this research, the highest rate of CL frequency was among the 21-30 years old age group (28.8 %) and the least rate (8.9 %) was in the age group of more than 50 years old. There is an agreement between our findings about the high rate of infection in patients who traveling to the rural areas of Isfahan and Kashan with the previous reports. The disease is reported to be endemic for many years in Isfahan and. Kashan (Talari, 2006)

In this study the location of lesions were on the hands and arm (48.6 %), face (27.3 %), legs (22.6 %) and other parts of the body (1.37 %). Because the phlebotomies attack the exposed area of the body to suck the blood, the lesions mostly appears in the hands, face and legs and upper parts of the body, which may be due to the outdoor sleeping on the terraces or yards without using bed net during summer.

In conclusion, the results indicated that although CL is endemic in many parts of Iran, and the frequency of non leishmanial skin lesions is high, and because of misdiagnosing CL lesions, performed parasitological smear isn't an adequate method and must used parallel with culture and other techniques. A timely and definitive diagnosis of CL is important for initiation appropriate clinical management and treatment of this disease. Microscopy may be the simplest method of achieving these, but undiagnosed cases associated with this method show its inadequate sensitivity.

Correspondence to

Dr. H. Nahrevanian, Department of Parasitology, Pasteur Institute of Iran, Pasteur Avenue, Tehran 1316943551, Iran Tel / Fax: +98-21-66968855, E-mail: mobcghn@yahoo.co.uk