Meriones libycus (Rodentia: Gerbillidae), a possible reservoir host of zoonotic cutaneous leishmaniasis in Riyadh province, Saudi Arabia

Geographic distribution of Meriones shawi and Psammomys obesus, the main reservoirs and Phlebotomus papatasi vector of zoonotic cutaneous leishmaniasis in Middle East and North Africa

Rodents play a significant role in the balance of a terrestrial ecosystem; they are considered prey for many predators like owls and snakes. However, they present a high risk to agriculture (damaging crops) and health. These rodents are the main reservoirs of some vector-borne diseases like leishmaniasis. Meriones shawi (MS) and Psammomys obesus (PO) are the primary Zoonotic cutaneous leishmaniasis (ZCL) reservoirs in the Middle East and North Africa (MENA). A review on the MS and PO at the MENA scale was explored. A database of about 1500 papers was used. 38 sites were investigated as foci for MS and 36 sites for PO, and 83 sites of Phlebotomus papatasi (Pp) in the studied region. An updated map at the regional scale and the trend of the reservoir distribution was carried out using a performing proper density analysis. In this paper, climatic conditions and habitat characteristics of these two reservoirs were reviewed. The association of rodent density with some climatic variables is another aspect explored in a case study from Tunisia in the period 2009–2015 using Pearson correlation. Lastly, the protection and control measures of the reservoir were analyzed. The high concentration of the MS, PO, and Pp can be used as an indicator to identify the high-risk area of leishmaniasis infection.

Demographical and population dynamics impact on public health of cutaneous Leishmaniasis in Al-Madinah Almonawra, Saudi Arabia

Background

A cross-sectional study conducted in Al-Madinah Almonawra in KSA held during the period from March 2014–March 2015.

Aim of the study

This study aimed at analyzing the effect of population dynamics on the current situation of cutaneous leishmaniasis in Al-Madinah Almonawarah area, a holy city that attracts millions of muslims annually.

Methodology

Epidemiological and clinical data were collected by especial questionnaire and laboratory specimens were collected using skin scraping and needle aspiration. Staining and direct microscopy were done. LST was conducted. Analysis was done using SPSS program.

Results

The study included 164 patients, all of them were men. Saudi nationality comprised around 20% of the study group, the majority were Egyptians, 26.2%, followed by Pakistani, 21.3%.

Conclusion

The presence of non-Saudi nationality as foreign workers, immigrants and refugees has worsened the current situation of the disease.

Old World cutaneous leishmaniasis treatment response varies depending on parasite species, geographical location and development of secondary infection

BACKGROUND

In the Kingdom of Saudi Arabia (KSA), Leishmania major and L. tropica are the main causative agents of Old World cutaneous leishmaniasis (CL). The national CL treatment regimen consists of topical 1% clotrimazole/2% fusidic acid cream followed by 1-2 courses of intralesional sodium stibogluconate (SSG); however, treatment efficacy is highly variable and the reasons for this are not well understood. In this study, we present a complete epidemiological map of CL and determined the efficacy of the standard CL treatment regime in several endemic regions of KSA.

RESULTS

Overall, three quarters of patients in all CL-endemic areas studied responded satisfactorily to the current treatment regime, with the remaining requiring only an extra course of SSG. The majority of unresponsive cases were infected with L. tropica. Furthermore, the development of secondary infections (SI) around or within the CL lesion significantly favoured the treatment response of L. major patients but had no effect on L. tropica cases.

CONCLUSIONS

The response of CL patients to a national treatment protocol appears to depend on several factors, including Leishmania parasite species, geographical location and occurrences of SI. Our findings suggest there is a need to implement alternative CL treatment protocols based on these parameters.

Leishmania majorinfection in the fat sand ratPsammomys obesusin Tunisia: interaction of host and parasite populations

The causative agent of cutaneous leishmaniasis, Leishmania major, was studied in a Tunisian population of the fat sand rat, Psammomys obesus. Seasonal changes in the abundances of parasite and host were monitored in a longitudinal field survey lasting 21 months. Overall, 566 P. obesus, collected during 10 trapping sessions between May 1995 and January 1997, were examined. Analysis of prevalence, using logistic regression, revealed that extrinsic factors, such as season and climatic conditions, and intrinsic factors, such as host age, have a combined effect. Leishmania major showed a seasonal pattern, with most transmission occurring in late summer and in autumn, when prevalences were 7.5- and 6.6-fold higher, respectively, than in spring. Prevalence peaked, at 70%, in September 1995 and then decreased to 0% in June 1996. The same temporal fluctuation was observed during the second study year, albeit among prevalences that were relatively low because of unusually dry conditions. Prevalence was highly dependent on the age of the P. obesus, and season and age acted in synergy so that the rodents were highly infected in late summer and in autumn. Prevalence was not correlated with the relative density of the P. obesus and also appeared independent of gender. Although the ear lesions observed on 378 sand rats during a 1-year survey were closely associated with Leishmania infection, such lesions were not good predictors of infection, as 35% of the rodents found to be infected had no visible lesions on their ears. The prevalences of Leishmania infection observed in this study, among P. obesus living in monospecific colonies, were generally lower than those observed in other studies of P. obesus. It seems possible that P. obesus living in monospecific colonies could have a lesser role in propagating the parasite than those living in plurispecific colonies of rodents, and act as an 'epidemiological sink'.

Fluconazole for the treatment of cutaneous leishmaniasis caused by Leishmania major

BACKGROUND

Whereas certain oral antifungal azoles are well documented to have activity against leishmania, data on the efficacy of fluconazole for leishmaniasis are limited. We conducted a controlled trial in Saudi Arabia of fluconazole for the treatment of cutaneous leishmaniasis caused by Leishmania major.

METHODS

This randomized, double-blind, placebo-controlled trial assessed the efficacy of oral fluconazole, in a dose of 200 mg daily for six weeks, in the treatment of parasitologically confirmed cutaneous leishmaniasis. The primary outcome measure was the time to the complete healing of all lesions.

RESULTS

A total of 106 patients were assigned to receive fluconazole, and 103 patients were assigned to receive placebo. Follow-up data were available for 80 and 65 patients, respectively. At the three-month follow-up, healing of lesions was complete for 63 of the 80 patients in the fluconazole group (79 percent) and 22 of the 65 patients in the placebo group (34 percent; relative risk of complete healing, 2.33 [95 percent confidence interval, 1.63 to 3.33]). According to an intention-to-treat analysis, the rates of healing were 59 percent and 22 percent, respectively (relative risk, 2.76 [95 percent confidence interval, 1.84 to 4.12]). Sodium stibogluconate was offered to 11 patients in the fluconazole group who returned for follow-up (14 percent) and 33 of those in the placebo group (51 percent) in whom oral treatment was judged to have failed. According to a Kaplan-Meier analysis, the time to healing was shorter for the fluconazole group (median, 8.5 weeks, as compared with 11.2 weeks in the placebo group; P<0.001 by the log-rank test). Side effects were mild and similar in both groups.

CONCLUSIONS

A six-week course of oral fluconazole is a safe and useful treatment for cutaneous leishmaniasis caused by L. major.

Detection of antibodies to Leishmania donovani in animals in a kala-azar endemic region in eastern Sudan: a preliminary report

The prevalence of antibodies against Leishmania donovani in selected domestic and wild animal species in 2 villages in Sudan with active L. donovani transmission in humans was investigated. Screening of domestic animals (donkeys, cows, sheep, goats, camels and dogs) with the direct agglutination test (DAT) detected reaction rates above the cut-off titres in donkeys (68.7%), cows (21.4%) and goats (8.5%), and which were also found in wild rats (5.5%). Sera of sheep, camels and dogs had a weak agglutination reaction below the cut-off titre. Testing of the same sera by enzyme-linked immunosorbent assay (ELISA), against a lysate of L. donovani promastigotes, showed reaction rates above the cut-off optical density in cows (47.6%), goats (13.6%), and in rats (4.1%). No Leishmania parasite was isolated from spleen, liver, bone-marrow or spleen of Nile rats.

Meriones libycus and Rhombomys opimus (Rodentia: Gerbillidae) are the main reservoir hosts in a new focus of zoonotic cutaneous leishmaniasis in Iran

Following an epidemic of zoonotic cutaneous leishmaniasis (ZCL) around Badrood city, central Iran, Meriones libycus were found to be naturally infected with Leishmania major zymodeme MON-26 (= LON-1) in the villages of Matinabad and Fami, 12 km north-west of Badrood. This is the first isolation and characterization of L. major from M. libycus in Iran, in an area where ZCL has been present recently. M. libycus is probably the principal reservoir host in this area, but the main reservoir host further east is Rhombomys opimus. Parasites were not found in Hemiechinus auritis. The main, proven vector to humans and gerbils is Phlebotomus (Phlebotomus) papatasi. The close contact between vectors and reservoirs creates a very efficient cycle for the transmission of the disease.