Mohamed Mahmoud El Alem

Background: The Hepatitis B virus (HBV) vaccine is used worldwide as an efficient tool to prevent the occurrence of chronic HBV infection and the subsequent liver disease. However, despite decades of vaccination campaigns, millions of new infections are still reported every year. Here, we aimed to assess the nationwide HBV vaccination coverage in Mauritania as well as the presence of protective levels of the antibodies against HBV surface antigen (HBsAb) following vaccination in a sample of children immunized as infants. Methods: To evaluate the frequency of fully vaccinated and seroprotected children in Mauritania, a prospective serological study was conducted in the capital. First, we evaluated the pediatric HBV vaccine coverage in Mauritania between 2015 and 2020. Then, we examined the level of antibodies against HBV surface antigen (HBsAb) in 185 fully vaccinated children (aged 9 months to 12 years) by ELISA using the VIDAS hepatitis panel for Minividas (Biomerieux). These vaccinated children were sampled in 2014 or 2021. Results: In Mauritania, between 2016 and 2019, more than 85% of children received the complete HBV vaccine regimen. While 93% of immunized children between 0 and 23 months displayed HBsAb titer >10 IU/L, the frequency of children with similar titers decreased to 63, 58 and 29% in children aged between 24–47, 48–59 and 60–144 months, respectively. Conclusions: A marked reduction in the frequency of HBsAb titer was observed with time, indicating that HBsAb titer usefulness as marker of protection is short lived and prompting the need for more accurate biomarkers predictive of long-term protection.

Introduction: In Africa, the first case of COVID-19 was reported in February 2020. Mauritania’s first case was confirmed in March 2020. Methodology: We provide an update of the COVID-19 epidemic in Mauritania as of December 2020, and describe the country’s Health System Response. Results: In total, 133,749 diagnostic tests were performed, 14,364 (10.7%) were positive (309 cases/100,000 inhabitants). Case fatality rate was 2.4%. The 20-39 year-olds (41%) and males (59.1%) were most commonly affected. Comorbidities among fatal cases included cardiovascular diseases (44.8%) and diabetes (37.1%). Clinical symptoms included fever (57%), cough (52%), running nose (47%) and headache (26%). After the first case, prevention measures were progressively tightened, and quarantine implemented for all suspected cases. Schools and universities were closed, and flights to Mauritania suspended. Restaurants and cafeterias were closed, and night curfews installed. Friday prayers were suspended nationwide, and movements between regions restricted. These measures helped to contain the spread of SARS-CoV-2 during the first pandemic wave, which peaked in June 2020 with low rates. However, the number of daily cases reached high levels in December 2020, during the second wave (40.1% of all cases and 48.9% of deaths). During the first wave, there were 38 ICU beds nationwide, but the ICU’s capacity increased in short time. Conclusions: Mauritania has passed through the first pandemic wave with relatively low case fatality rates, currently being at the end of the second wave. As the country’s health system is very vulnerable, there is a need for strict public health measures during epidemics.

In Morocco, Leishmania infantum species is the main causative agents of visceral leishmaniasis (VL). However, cutaneous leishmaniasis (CL) due to L. infantum has been reported sporadically. Moreover, the recent geographical expansion of L. infantum in the Mediterranean subregion leads us to suggest whether the nonsporadic cases of CL due to this species are present. In this context, this review is written to establish a retrospective study of cutaneous and visceral leishmaniasis in northern Morocco between 1997 and 2018 and also to conduct a molecular study to identify the circulating species responsible for the recent cases of leishmaniases in this region. Data concerning leishmaniases cases were collected from the Epidemiology and Disease Control Directorate from 1997 to 2018. Human samples obtained from peripheral laboratories were examined using PCR-ITS1 method. The ITS1 products were subjected to digestion with the restriction endonuclease Mn1-I. Between 1997 and 2018, a total of 1,255 cases of cutaneous and visceral leishmaniasis were recorded in Tangier-Tetouan-Al Hoceima Region, i.e., 1.56% of the reported cases in Morocco (1,255/80,299). Concerning the geographical study covering the period 2007-2018, 79.5% (105/132) of the sectors were affected by leishmaniases. The molecular results showed that Humans were found to be infected with the L. infantum species with a high infection rate compared to L. tropica infection. Moreover, molecular characterization using ITS1 PCR-RFLP showed that the density of L. infantum was significantly higher (n = 68/81; 84%) than that of L. tropica (n = 13/81; 16%) (P-value 9.894e-10). While regarding visceral leishmaniasis, L. infantum was the only species responsible of this form. These findings of this study showed the emergence of L. infantum in Morocco and suggest that this species might be more prevalent than previously thought. Furthermore, the molecular determination of L. infantum will be helpful for control strategies by taking into consideration the reservoir of this species.

Cutaneous leishmaniasis (CL) is widely distributed in Morocco where its geographical range and incidence are related to environmental factors. This study aimed to examine the impact of several factors on the distribution of CL in Boulemane Province, which is characterized by several microclimates, and to identify the Leishmania species circulating in these areas. Ordinary least squares regression (OLSR) analysis was performed to study the impact of poverty, vulnerability, population density, urbanization and bioclimatic factors on the distribution of CL in this province. Molecular characterization of parasites was performed using a previously described PCR-RFLP method targeting the ITS1 of ribosomal DNA of Leishmania. A total of 1009 cases were declared in Boulemane Province between the years 2000 and 2015 with incidences fluctuating over the years (P = 0.007). Analyzing geographical maps of the study region identified four unique microclimate areas; sub-humid, semi-arid, arid and Saharan. The geographical distribution and molecular identification of species shows that the Saharan microclimate, characterized by the presence of Leishmania major was the most affected (47.78%) followed by semi-arid area where Leishmania tropica was identified in three districts. Among several environmental factors included in the study, poverty had the greatest influence on the spatial extension of the disease in this province. The incidence of CL in Boulemane Province varies between microclimate areas, and environmental factors partly explain this variation. However, the existence of CL in the most affected districts is mainly related to poverty, population movement and human behavior. To our knowledge, this the first study utilizing molecular techniques to confirm L. tropica and L. major as the causative agents of CL in Boulemane Province. Our findings indicate that the spatial and temporal distribution of CL in Boulemane Province is strongly related to poverty and population movement.

Leishmaniasis is considered among the main endemic diseases in Morocco. However, further knowledge about epidemiological aspects of this disease is needed in several provinces to plan control and preventive strategies to tackle the disease. The present study aims to determine the epidemiological aspect of cutaneous and visceral leishmaniasis in Taza Province from 2007–2014 and to identify the circulating species in this province. The temporal study from 2007 to 2014 showed that the number of cutaneous leishmaniasis cases increased since 2010. During the period of study, most leishmaniasis cases were detected in both urban and rural areas with 34% of cases detected in two urban localities, Bab Zitouna and Bab tété with 297 and 106 cases, respectively. The molecular study of cutaneous leishmaniasis showed the presence of non-sporadic Leishmania infantum and Leishmania tropica in this province. Regarding visceral leishmaniasis, Leishmania infantum is the species that has been identified. The epidemio-molecular study of leishmaniasis in Taza Province showed the coexistence of two species of Leishmania in the same foci. They also indicated that CL due to Leishmania infantum is more prevalent than reported in the literature. These results will be helpful for the implementation of control strategies by targeting dogs that constitute a reservoir of Leishmania infantum.

In Errachidia province, the incidence of cutaneous leishmaniasis (CL) has increased over the past decade and it was higher in 2010 (860.34 per 100,000 inhabitants), with 3445 cases. The number of cases declined sharply and decreased from 3445 cases in 2010 to 8 cases in 2014 following the control action plan interventions. The total of patients was diagnosed only on clinical basis and the lesions were considered caused byL. major. The epidemiological study was conducted between 2001 and 2014 and the molecular detection of CL was studied to identify the circulating parasite species in this province by using the ITS1-PCR-RFLP methods. In 2010, the molecular identification of 11 samples revealed the presence ofL. majorin the most affected circles: Goulmima, Er-Rissani, and Errachidia. In 2014 the molecular characterization of 7 among 8 cases reported in this year showed the presence ofL. tropicain Errachidia circle. This is the first molecular identification ofL. tropicain Errachidia province. The detection of this species after the intensified control measures strategies suggests that it was probably dissipated through the dominance ofL. major.