The arch of the great saphenous vein: anatomical bases for failures and recurrences after surgical treatment of varices in the pelvic limb. About 54 dissections

The arch of the great saphenous vein presents numerous tributaries. Misappreciation of their anatomical variations might cause recurrence after surgical treatment of varices. We dissected 54 inguino-femoral regions of fresh, black African corpses. Our purpose was to study the anatomical variations in the vein confluents of the arch of the great saphenous vein; its positions in relation to the external pudendal artery; establish palpable anatomical markers for its surgical approach. The conventional type in a ‘vein star’ shape was not the most frequent. Upper or abdominal common vein produced through the merging of superficial veins of the anterior abdominal wall and genital or internal common vein were more frequent. An anterior saphenous vein was found in 23 cases. The external pudendal artery crossed beneath the arch of the great saphenous vein cross in 56% of cases and previously in 44% of cases. On average, the top of the arch of the great saphenous vein was projected out 10.88 cm from the ventral and cranial iliac spine, 3.83 cm from the pubic tubercle and 4.19 cm from the inguinal ligament. In view of our results, variations are real. Knowing and taking them into account are essential to prevent recurrences after surgical treatment of varices of the pelvic limb.     

Prevention of infection in a surgical environment in the regional hospitals of Senegal

This study evaluated the attitudes and practices of the personnel with respect to the prevention of nosocomial infections in a hospital environment. We carried out a qualitative survey of all categories of personnel between July 1998 and March 1999, at the five regional hospitals in Senegal (Thiés, Kaolack, Saint-Louis, Diourbel, and Louga). Data were collected in two ways: using a questionnaire to evaluate knowledge and by observing the attitudes and practices of the personnel. Hands were rarely washed before and after each procedure and surgical washing was often performed in poor conditions. The decontamination of soiled equipment was ineffective. Reusable instruments were washed directly with bare hands or by individuals wearing used surgical gloves. The equipment used for sterilization was dilapidated and unsuitable and the norms for sterilization were seldom respected. Circulation in the region of the operating theatre was disorganized, if not anarchic. The personnel had a high risk of contamination from blood. Biomedical waste was not decontaminated: it was collected poorly and disposed of directly into the environment. None of the sites visited had a program of waste incineration. In conclusion, at the sites visited, there is a high risk of nosocomial contamination during care and the reuse of equipment, for both the staff and the patients treated.     

Investigation of deaths in an area of groundnut plantations in Casamance,South of Senegal after exposure to Carbofuran,Thiram and Benomyl

Between May and October 2000, the Regional Health Office of Kolda Region in the south of Senegal, West Africa, reported an epidemic of an unknown illness characterized by thoracic pain, dyspnea and edemas of limb and face. The epidemic covered a radius of approximately 40 km (24 miles) between the districts of Kolda and Sedhiou in Kolda Region. Cases were mostly men whose age ranged between 12 and 60 years old. Investigation revealed that they had been exposed to pesticides distributed by the government to groundnut farmers. The signs and symptoms suggested intoxication with carbamates, carbofurans, and possibly thiram, contained in the pesticides distributed with the groundnut seeds. Government distribution created an excessive use of pesticides in the farms, and consequently an overexposure of the subjects who handled the seeders, especially young males but also a small proportion of women who worked in the groundnut fields. Many of these subjects, not accustomed to handle pesticides, came to overestimate the quantity of product to fill the seeder. It should be noted that the policy of distribution of pesticides in Senegal, which presents risk of poisoning, was not systematically accompanied by sufficient information on the danger of the products and of certain precautions that should be taken during their use.     

Domestic transmission of Rift Valley Fever virus in Diawara (Senegal) in 1998

In 1998, circulation of the Rift Valley Fever (RVF) virus was revealed in Diawara by detection of IgM antibodies in sheep and isolation of the virus from mosquitoes caught outside a village. A seroprevalence study was carried out. Finger-prick blood samples, individual and collective details were obtained. One thousand five hundred twenty people (6 months - 83 years) were included. Overall prevalence in this group was approximately 5.2%. The prevalence in infants (6 months - 2 years) was 8.5%. Age, gender, contact with a pond, presence of sheep, and abortion among sheep, and individual or collective travel history were not statistically associated with prevalence. Prevalence increased significantly when the distance to a small ravine, located in the middle of the village, decreased. The results suggest a low, recent, not endemic circulation of the virus. Culex quinquefasciatus was captured near the ravine. This mosquito, similar to Culex pipiens, can play a similar role in human-to-human transmission of the RVF virus.     

The value of community participation in disease surveillance: a case study from Niger

A team of researchers, including one behavioral scientist (S.M.N.) and three epidemiologists (L.Q., O.S. and S.N.) conducted community analyses to assess the social and cultural factors that affect the detection and reporting of disease cases in a surveillance system, using acute flaccid paralysis (AFP) surveillance in Niger as a case study. Over a 60-day period in the country, the research team reviewed written field reports and interviewed epidemiologists, nurses, community members and persons in governmental and non-governmental organizations. Overall, we found that the logistical difficulties of travel and communication, which are common in developing countries, constrain the conventional surveillance system that relies on epidemiologists visiting sites to discover and investigate cases, particularly in rural areas. Other challenges include: community members' lack of knowledge about the possible link between a case of paralysis and a dangerous, communicable disease; lack of access to health care, including the low number of clinics and health care workers; cultural beliefs that favor seeking a local healer before consulting a nurse or physician; and health workers' lack of training in AFP surveillance. The quality of surveillance in developing countries can improve if a community-based approach is adopted. Such a system has been used successfully in Niger during smallpox-eradication and guinea worm-control campaigns. In a community-based system, community members receive basic education or more extensive training to motivate and enable them to notify health care staff about possible cases of disease in a timely fashion. Local organizations, local projects and local leaders must be included to ensure the success of such a program. In Niger we found sufficient quantities of this type of social capital, along with enough local experience of past health campaigns, to suggest that a community-based approach can improve the level of comprehensiveness and sensitivity of surveillance.     

Placental infection by Plasmodium falciparum in an urban area of Senegal

OBJECTIVES: This study aimed at describing the burden of malaria at delivery in a urban maternity in Senegal. We measured the prevalence of placental malaria infection. We described the association between placental malaria and low birth weight and the impact of chemoprophylaxis. STUDY AREA: Guediawaye is the most important suburb of the city of Dakar, Senegal, surrounded by a permanent marsh (niayes). Malaria in this area is hypo endemic transmission: 1 infective bite/person/year. An. arabiensis is the principal vector and P. falciparum (98%) the most frequent species. The Maternité Roi Baudoin in Guediawaye is the gynecologic and obstetrical reference centre of this area with more than 6000 deliveries/year. METHODS: We carried out an exhaustive survey from August 98 to December 99 at the maternité Roi Baudoin in Guediawaye. The socio-demographic data, the clinical data and information about prophylaxy were collected by questionnary. For each woman at delivery, one placental apposition was carried out. Presence of trophozo?tes or schizontes indicated malaria placental infection. RESULTS: 8310 women were included in the study. They were from 13 to 49 years old with an average age of 26.1; 28% were primigravidae. The prevalence of placental malaria infection was 8.1% (674/8310) [Ic95: 7.4-8.8%]. Schizontes were present in 80.5% of infected placenta. The prevalence was 8.8% within primigravidae group and 7.4% in the other parity groups, p = 0.28 (NS). Placental infection was present all the year long. However, there were important seasonal variations. The risk of placental infection increased during seasonal transmission (> 10%) compared to the period of low transmission (3%). The prevalence of placental malaria was lower in the group of women who declares regular chloroquine intake compared with those who declared taking no prophylaxy or irregular prophylaxy (RR = 0.78 [0.62-0.98]). The risk of low birth weight was of 1.9 [1.6-2.1] when the placenta was infected compared with non infected placenta. CONCLUSION: This study indicates that placental malaria infection is frequent in this low transmission area where more than 70% of women declared taking regular chloroquine. This observation could be explained by a resistance of P. falciparum to chloroquine or a poor observance of chemoprophylaxis.     

Rapid, field-deployable method for genotyping and discovery of single-nucleotide polymorphisms associated with drug resistance in Plasmodium falciparum

Despite efforts to reduce malaria morbidity and mortality, drug-resistant parasites continue to evade control strategies. Recently, emphasis has shifted away from control and toward regional elimination and global eradication of malaria. Such a campaign requires tools to monitor genetic changes in the parasite that could compromise the effectiveness of antimalarial drugs and undermine eradication programs. These tools must be fast, sensitive, unambiguous, and cost-effective to offer real-time reports of parasite drug susceptibility status across the globe. We have developed and validated a set of genotyping assays using high-resolution melting (HRM) analysis to detect molecular biomarkers associated with drug resistance across six genes in Plasmodium falciparum. We improved on existing technical approaches by developing refinements and extensions of HRM, including the use of blocked probes (LunaProbes) and the mutant allele amplification bias (MAAB) technique. To validate the sensitivity and accuracy of our assays, we compared our findings to sequencing results in both culture-adapted lines and clinical isolates from Senegal. We demonstrate that our assays (i) identify both known and novel polymorphisms, (ii) detect multiple genotypes indicative of mixed infections, and (iii) distinguish between variants when multiple copies of a locus are present. These rapid and inexpensive assays can track drug resistance and detect emerging mutations in targeted genetic loci in P. falciparum. They provide tools for monitoring molecular changes associated with changes in drug response across populations and for determining whether parasites present after drug treatment are the result of recrudescence or reinfection in clinical settings.     

A flow cytometry‐based assay for measuring invasion of red blood cells by Plasmodium falciparum

Variability in the ability of the malaria parasite Plasmodium falciparum to invade human erythrocytes is postulated to be an important determinant of disease severity. Both the parasite multiplication rate and erythrocyte selectivity are important parameters that underlie such variable invasion. We have established a flow cytometry‐based method for simultaneously calculating both the parasitemia and the number of multiply‐infected erythrocytes. Staining with the DNA‐specific dye SYBR Green I allows quantitation of parasite invasion at the ring stage of parasite development. We discuss in vitro and in vivo applications and limitations of this method in relation to the study of parasite invasion. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.