[Cryptosporidiosis in Senegalese children: prevalence study and use of ELISA serologic diagnosis]

This is a prospective, descriptive and analytic study conducted from July 2011 to September 2011 at the Children National Hospital Albert Royer of Dakar and at the Vélingara Health District. It was focused on children under 15 without reference to HIV status. For each child, a sample of stool was examined by the Ziehl-Neelsen modified staining and by ELISA using the "Cryptosporidium Antigen Detection Microwell ELISA kit" designed to detect Cryptosporidium spp antigens. The aim of our study was to determine the prevalence of cryptosporidiosis in rural and hospital areas and to measure the performance of the ELISA kit that we used. Out of the 375 stool examinations performed with the Ziehl-Neelsen modified staining, 17 had revealed the presence of Cryptosporidium spp (4.53%). The prevalence in rural areas was 2% while the hospital prevalence was 7.4%, of which 1.8% (1/57) were from urban areas and 9.8% (12/122) from suburban areas. No positive case was observed in children over 10 years. By ELISA, 23 positives cases were reported corresponding to a prevalence of 6.13% (1.8% in children living in urban areas, 13.1% in children from suburban areas and 3%living in rural areas).The correlation of this assay with the Ziehl-Neelsen modified staining, considered as the reference method, found that this assay had a sensitivity of 58.82% and a high specificity reaching 96.37%. The positive predictive value (PPV) was 43.4% while the negative predictive value was 98%. Cryptosporidiosis is a significant cause of parasitic infection among children in Senegal. Antigen detection of Cryptosporidium spp by ELISA in stool can be a complementary tool in the diagnosis of cryptosporidiosis.

[Familial congenital hypomagnesemia revealed by neonatal convulsions]

Congenital hypomagnesemia is a rare disease, with an impact on cognitive and neurological development. We report on three familial cases of congenital hypomagnesemia, two boys and one girl who belong to the same consanguineous family. They all presented neonatal seizures and a psychomotor developmental delay. Cerebral computed tomography showed cerebral atrophy and calcifications in one case and magnetic resonance imaging found predominant cerebellar atrophy in the two other cases. All three patients also had hypocalcemia, hyperphosphoremia, and hypomagnesemia. The parathyroid hormone blood level was low in two cases and normal in the third. One 7-month old patient died. The others received a supplementation of calcium and magnesium, which normalized calcemia, phosphatemia but not magnesemia, which remained low despite high doses. They have both developed cognitive and behavioral impairments.

Prevalence of molecular markers of drug resistance in an area of seasonal malaria chemoprevention in children in Senegal

Background

In sub-Saharan Africa, malaria is the leading cause of morbidity and mortality especially in children. In Senegal, seasonal malaria chemoprevention (SMC) previously referred to as intermittent preventive treatment in children (IPTc) is a new strategy for malaria control in areas of high seasonal transmission. An effectiveness study of SMC, using sulphadoxine-pyrimethamine (SP) plus amodiaquine (AQ), was conducted in central Senegal from 2008 to 2010 to obtain information about safety, feasibility of delivery, and cost effectiveness of SMC. Here are report the effect of SMC delivery on the prevalence of markers of resistance to SP and AQ.

Methods

This study was conducted in three health districts in Senegal with 54 health posts with a gradual introduction of SMC. Three administrations of the combination AQ + SP were made during the months of September, October and November of each year in children aged less than 10 years living in the area. Children were surveyed in December of each year and samples (filter paper and thick films) were made in 2008, 2009 and 2010. The prevalence of mutations in the pfdhfr, pfdhps, pfmdr1 and pfcrt genes was investigated by sequencing and RTPCR in samples positive by microscopy for Plasmodium falciparum.

Results

Mutations at codon 540 of pfdhps and codon 164 of pfdhfr were not detected in the study. Among children with parasitaemia at the end of the transmission seasons, the CVIET haplotypes of pfcrt and the 86Y polymorphism of pfmdr1 were more common among those that had received SMC, but the number of infections detected was very low and confidence intervals were wide. The overall prevalence of these mutations was lower in SMC areas than in control areas, reflecting the lower prevalence of parasitaemia in areas where SMC was delivered.

Conclusion

The sensitivity of P. falciparum to SMC drugs should be regularly monitored in areas deploying this intervention. Overall the prevalence of genotypes associated with resistance to either SP or AQ was lower in SMC areas due to the reduced number of parasitaemia individuals.

Selection of antimalarial drug resistance after intermittent preventive treatment of infants and children (IPTi/c) in Senegal

Our study investigated the possible impact of SP-IPT given to infants and children on the prevalence of SP-resistant haplotypes in the Plasmodium falciparum genes Pfdhfr and Pfdhps, comparing sites with and without IPTi/c. P. falciparum positive samples (N = 352) collected from children < 5 years were analyzed to determine the prevalence of SP resistance-related haplotypes by nested PCR followed by sequence-specific oligonucleotide probe-enzyme-linked immunosorbent assay. The prevalence of the Pfdhfr triple mutant haplotype (CIRN) increased in both groups, but only significantly in the IPTi/c group from 41% to 65% in 2011 (P = 0.005). Conversely, the Pfdhps 437G mutation decreased in both groups from 44.6% to 28.6% (P = 0.07) and from 66.7% to 47.5% (P = 0.02) between 2010 and 2011 in the control and the IPTi/c groups, respectively. A weak trend for decreasing prevalence of quadruple mutants (triple Pfdhfr + Pfdhps 437G) was noted in both groups (P = 0.15 and P = 0.34). During the two cross-sectional surveys some significant changes were observed in the SP resistance-related genes.

Efficacy and tolerability of a new formulation of artesunate-mefloquine for the treatment of uncomplicated malaria in adult in Senegal: open randomized trial

Background

Prompt treatment of malaria attacks with arteminisin-based combination therapy (ACT) is an essential tool for malaria control. A new co-blister tablet of artesunate-mefloquine (AM) with 25 mg/kg mefloquine has been developed for the management of uncomplicated malaria attacks. This non-inferiority randomized trial, was conducted to evaluate the efficacy and safety of the new formulation of AM in comparison to artemether-lumefantrine (AL) for the treatment of acute uncomplicated Plasmodium falciparum malaria in adults in Senegal.

Methods

The study was carried out from September to December 2010 in two health centres in Senegal. The study end points included (i) PCR corrected adequate clinical and parasitological response (ACPR) at day 28, (ii) ACPR at days 42 and 63, (iii) parasites and fever clearance time, (iv) incidence of adverse events and patients biological profile at day 7 using the WHO 2003 protocol for anti-malarial drug evaluation.

Results

Overall, 310 patients were randomized to receive either AM (n = 157) or AL (n = 153). PCR corrected ACPR at day 28 was at 95.5% in the AM arm while that in the AL arm was at 96.7% (p = 0.83). Therapeutic efficacy was at 98.5% in the AM arm versus 98.2% in the AL group at day 42 (p = 1). At day 63, ACPR in the AM and AL arms was at 98.2% and 97.7%, respectively (p = 0.32). The two treatments were well tolerated with similar biological profile at day 7. However, dizziness was more frequent in the AM arm.

Conclusion

Artesunate-mefloquine (25 mg/Kg mefloquine) is efficacious and well-tolerated for the treatment of uncomplicated P. falciparum malaria in adult patients.

The association between malaria parasitaemia, erythrocyte polymorphisms, malnutrition and anaemia in children less than 10 years in Senegal: a case control study

Background

Malaria and anaemia (Haemoglobin <11 g/dl) remain frequent in tropical regions and are closely associated. Although anaemia aetiologies are known to be multi-factorial, most studies in malaria endemic areas have been confined to analysis of possible associations between anaemia and individual factors such as malaria. A case control study involving children aged from 1 to 10 years was conducted to assess some assumed contributors to anaemia in the area of Bonconto Health post in Senegal.

Methods

Study participants were randomly selected from a list of children who participated in a survey in December 2010. Children aged from 1 to 10 years with haemoglobin level below 11 g/dl represented cases (anaemic children). Control participants were eligible if of same age group and their haemoglobin level was >= 11 g/dl. For each participant, a physical examination was done and anthropometric data collected prior to a biological assessment which included: malaria parasitaemia infection, intestinal worm carriage, G6PD deficiency, sickle cell disorders, and alpha-talassaemia.

Results

Three hundred and fifty two children < 10 years of age were enrolled (176 case and 176 controls). In a logistic regression analysis, anaemia was significantly associated with malaria parasitaemia (aOR=5.23, 95%CI[1.1-28.48]), sickle cell disorders (aOR=2.89, 95%CI[1,32-6.34]), alpha-thalassemia (aOR=1.82, 95%CI[1.2-3.35]), stunting (aOR=3.37, 95%CI[1.93-5.88], age ranged from 2 to 4 years (aOR=0.13, 95%CI[0.05-0.31]) and age > 5 years (aOR=0.03, 95%CI[0.01-0.08]). Stratified by age group, anaemia was significantly associated with stunting in children less than 5 years (aOR=3.1 95%CI[1.4 – 6.8]), with, sickle cell disorders (aOR=3.5 95%CI [1.4 – 9.0]), alpha-thalassemia (or=2.4 95%CI[1.1–5.3]) and stunting (aOR=3.6 95%CI [1.6–8.2]) for children above 5 years. No association was found between G6PD deficiency, intestinal worm carriage and children’s gender.

Conclusion

Malaria parasitaemia, stunting and haemoglobin genetic disorders represented the major causes of anaemia among study participants. Anaemia control in this area could be achieved by developing integrated interventions targeting both malaria and malnutrition.

Assessment of the molecular marker of Plasmodium falciparum chloroquine resistance (Pfcrt) in Senegal after several years of chloroquine withdrawal

As a result of widespread antimalarial drug resistance, all African countries with endemic malaria have, in recent years, changed their malaria treatment policy. In Senegal, the health authorities changed from chloroquine (CQ) to a combination of sulfadoxine-pyrimethamine (SP) plus amodiaquine (AQ) in 2003. Since 2006, the artemisinin combination therapies (ACTs) artemether-lumefantrine (AL) and artesunate plus amodiaquine (AS/AQ) were adopted for uncomplicated malaria treatment. After several years of CQ withdrawal, the current study wished to determine the level of CQ resistance at the molecular level in selected sites in Senegal, because the scientific community is interested in using CQ again. Finger prick blood samples were collected from Plasmodium falciparum-positive children below the age of 10 years (N = 474) during cross-sectional surveys conducted in two study sites in Senegal with different malaria transmission levels. One site is in central Senegal, and the other site is in the southern part of the country. All samples were analyzed for single nucleotide polymorphisms (SNPs) in the P. falciparum CQ resistance transporter gene (Pfcrt; codons 72-76) using polymerase chain reaction (PCR) sequence-specific oligonucleotide probe (SSOP) enzyme-linked immunosorbent assay (ELISA) and real-time PCR methods. In total, the 72- to 76-codon region of Pfcrt was amplified in 449 blood samples (94.7%; 285 and 164 samples from the central and southern sites of Senegal, respectively). In both study areas, the prevalence of the Pfcrt wild-type single CVMNK haplotype was very high; in central Senegal, the prevalence was 70.5% in 2009 and 74.8% in 2010, and in southern Senegal, the prevalence was 65.4% in 2010 and 71.0% in 2011. Comparing data with older studies in Senegal, a sharp decline in the mutant type Pfcrt prevalence is evident: from 65%, 64%, and 59.5% in samples collected from various sites in 2000, 2001, and 2004 to approximately 30% in our study. A similar decrease in mutant type prevalence is noted in other neighboring countries. With the continued development of increased CQ susceptibility in many African countries, it may be possible to reintroduce CQ in the near future in a drug combination; it could possibly be given to non-vulnerable groups, but it demands close monitoring of possible reemergence of CQ resistance development.

[Biomedical waste management in five hospitals in Dakar, Senegal]

Biomedical waste is currently a real health and environmental concern. In this regard, a study was conducted in 5 hospitals in Dakar to review their management of biomedical waste and to formulate recommendations. This is a descriptive cross-sectional study conducted from 1 April to 31 July 2010 in five major hospitals of Dakar. A questionnaire administered to hospital managers, heads of departments, residents and heads of hospital hygiene departments as well as interviews conducted with healthcare personnel and operators of waste incinerators made it possible to assess mechanisms and knowledge on biomedical waste management. Content analysis of interviews, observations and a data sheet allowed processing the data thus gathered. Of the 150 questionnaires distributed, 98 responses were obtained representing a response rate of 65.3%. An interview was conducted with 75 employees directly involved in the management of biomedical waste and observations were made on biomedical waste management in 86 hospital services. Sharps as well as blood and liquid waste were found in all services except in pharmacies, pharmaceutical waste in 66 services, infectious waste in 49 services and anatomical waste in 11 services. Sorting of biomedical waste was ill-adapted in 53.5% (N = 46) of services and the use of the colour-coding system effective in 31.4% (N = 27) of services. Containers for the safe disposal of sharps were available in 82.5% (N = 71) of services and were effectively utilized in 51.1% (N = 44) of these services. In most services, an illadapted packaging was observed with the use of plastic bottles and bins for waste collection and overfilled containers. With the exception of Hôpital Principal, the main storage area was in open air, unsecured, with biomedical waste littered on the floor and often mixed with waste similar to household refuse. The transfer of biomedical waste to the main storage area was done using trolleys or carts in 67.4% (N = 58) of services and wheelbarrows in 33.7% (N = 29). Biomedical waste was disposed of in old incinerators or in artisanal ovens with a great deal of smoke emanating from these. Working conditions were deemed poor by 81.3% (N = 61) of employees interviewed and personal protection equipment was available in 45.3% (N = 39) of services. Knowledge about biomedical waste management was deemed satisfactory by 62.6% (N = 47) of interviewees and 80% (N = 60) were aware of the health risks related to biomedical waste. The poor management of biomedical waste is a reality in hospital facilities in Dakar. This can be addressed by increasing the awareness of managers for an effective application of the legislation, implementing realistic management programmes and providing the appropriate on-the-job training to staff members.

[Management of neurological emergencies in developing country: example of Senegal]

Senegal, like many African countries is facing the so-called demographic and epidemiological transition leading to the development of neurological diseases. These diseases dominated by stroke and status epilepticus are public health priorities with a high prevalence, high lethality and high cost of care. These diseases are managed at the department of neurology, Fann Teaching Hospital, Dakar-Senegal (the only one) with a 65 beds capacity. Unfortunately, access care to the clinic is lately associated with human and material resource scarcity. To improve the management of patients at the clinic, it is important to increase resources (human and material), sensitize the population on early access to health services and prevention of risk factors.

Impact of combining intermittent preventive treatment with home management of malaria in children less than 10 years in a rural area of Senegal: a cluster randomized trial

BACKGROUND

Current malaria control strategies recommend (i) early case detection using rapid diagnostic tests (RDT) and treatment with artemisinin combination therapy (ACT), (ii) pre-referral rectal artesunate, (iii) intermittent preventive treatment and (iv) impregnated bed nets. However, these individual malaria control interventions provide only partial protection in most epidemiological situations. Therefore, there is a need to investigate the potential benefits of integrating several malaria interventions to reduce malaria prevalence and morbidity.

METHODS

A randomized controlled trial was carried out to assess the impact of combining seasonal intermittent preventive treatment in children (IPTc) with home-based management of malaria (HMM) by community health workers (CHWs) in Senegal. Eight CHWs in eight villages covered by the Bonconto health post, (South Eastern part of Senegal) were trained to diagnose malaria using RDT, provide prompt treatment with artemether-lumefantrine for uncomplicated malaria cases and pre-referral rectal artesunate for complicated malaria occurring in children under 10 years. Four CHWs were randomized to also administer monthly IPTc as single dose of sulphadoxine-pyrimethamine (SP) plus three doses of amodiaquine (AQ) in the malaria transmission season, October and November 2010. Primary end point was incidence of single episode of malaria attacks over 8 weeks of follow up. Secondary end points included prevalence of malaria parasitaemia, and prevalence of anaemia at the end of the transmission season. Primary analysis was by intention to treat. The study protocol was approved by the Senegalese National Ethical Committee (approval 0027/MSP/DS/CNRS, 18/03/2010).

RESULTS

A total of 1,000 children were enrolled. The incidence of malaria episodes was 7.1/100 child months at risk [95% CI (3.7-13.7)] in communities with IPTc + HMM compared to 35.6/100 child months at risk [95% CI (26.7-47.4)] in communities with only HMM (aOR = 0.20; 95% CI 0.09-0.41; p = 0.04). At the end of the transmission season, malaria parasitaemia prevalence was lower in communities with IPTc + HMM (2.05% versus 4.6% p = 0.03). Adjusted for age groups, sex, Plasmodium falciparum carriage and prevalence of malnutrition, IPTc + HMM showed a significant protective effect against anaemia (aOR = 0.59; 95% CI 0.42-0.82; p = 0.02).

CONCLUSION

Combining IPTc and HMM can provide significant additional benefit in preventing clinical episodes of malaria as well as anaemia among children in Senegal.