First insights into the genetic diversity and origin of Leishmania infantum in Mont Rolland (Thiès region, Senegal)

New Microsatellite Markers for Genetic Studies on Sergentomyia schwetzi (Diptera: Psychodidae): A Suspected Vector of Leishmania infantum (Trypanosomatida: Trypanosomatidae) in the Canine Leishmaniasis Focus of Mont-Rolland, Senegal

Visceral leishmaniasis is not endemic in West Africa, but prevalence of canine leishmaniasis and seroprevalence of Leishmania infantum infection in humans are high in the Mont Rolland community (Thiès region, Senegal). Previous studies in this area showed that Sergentomyia schwetzi could be the potential vector of Le. infantum. To precisely describe the biology and population structure of this potential vector, we identified eight novel microsatellite loci to characterize Se. schwetzi populations. We tested these loci in Se. schwetzi populations from five locations at Mont Rolland (Thiès, Senegal). All the loci were polymorphic, with a mean of 17.25 alleles (observed heterozygosity: 0.455). We did not detect any evidence of scoring errors due to stuttering and large allele dropout. Moreover, several of these loci were also amplified in six other sand fly species (Sergentomyia magna, Sergentomyia dubia, Sergentomyia minuta, Phlebotomus duboscqi, Phlebotomus perniciosus, and Phlebotomus ariasi). These preliminary results demonstrate the utility of these microsatellite markers for Se. schwetzi (and for the other sand fly species) population genetic studies.

Visceral Leishmaniasis in West Africa: Clinical Characteristics, Vectors, and Reservoirs

Visceral leishmaniasis (VL) is the most serious form of human leishmaniasis. VL is understudied in West Africa. The increasing number of patients at-risk, including persons living with HIV and other chronic immunosuppressive diseases, and likely underreporting of VL related to diagnostic challenges advocate for review of existing data to understand VL regional epidemiology. Our review aims to describe the clinical characteristics and epidemiology of Human VL (HVL) in West Africa. We conducted a literature search to identify peer-reviewed articles and grey literature sources using the search terms “Visceral leishmaniasis West Africa”, “Leishmania donovani West Africa”; and “Leishmania infantum West Africa”. Thirty published articles report HVL from seven countries, including The Gambia, Niger, Nigeria, Ivory Coast, Togo, Burkina Faso, and Guinea Bissau. Three countries report cases of Canine Visceral Leishmaniasis (CVL), including The Gambia, Senegal, and Burkina Faso. Niger, Nigeria, and Ivory Coast report the greatest number of HVL cases. As VL is present in West Africa, active surveillance, increased diagnostic capacity, and studies of vectors and reservoirs are essential to better understand VL epidemiology in the region.

A rapid high-resolution melting method for differentiation of Leishmania species targeting lack gene

OBJECTIVES

The aim of this research is to verify that if lack gene can be used for differentiation of Leishmania under HRM assay.

METHODS

Two specific primers were designed targeting polymorphic sites on the lack gene sequence. DNA from promastigotes of six species of Leishmania based on reference strains were tested following a HRM protocol. We also tested ten Chinese isolates in blind to validate our method.

RESULTS

Combined with amplicon of the two primers, the six reference strains can be easily discriminated without the effect of initial concentration of DNA templates. Ten Chinese isolates detected by our HRM method resulted in full accord with the standard identification results in previous study.

CONCLUSION

HRM is a rapid and reproducible method to discriminate different Leishmania species and lack gene is a potential novel biological characteristic for easy differentiation of Leishmania isolates in China.

Noma in an HIV infected patient in Guinea-Bissau: a case report

BACKGROUND

Noma is a multifactorial and multibacterial opportunistic infection that initially causes necrotic gingivitis but rapidly spreads to the nearby orofacial tissue resulting in sloughing and severe deformation of the facial structures. The majority of cases are seen in young children under the age of 6 years. Noma is strongly associated with poverty, malnutrition and immunosuppression, and is often preceded by severe systemic infections such as measles and malaria. Only few cases of noma infection in adults have been described.

CASE REPORT

We present here a case report with a 32-year-old Guinean woman who was diagnosed with noma infection and on that occasion discovered that she was HIV-1 seropositive. After treatment with amoxicillin/clavulanic acid and metronidazole for her noma infection the woman was transferred to the national hospital where antiretroviral treatment was initiated.

CONCLUSION

Noma is an opportunistic infection and immunodeficiencies such as HIV should always be suspected when presenting in an adult patient.