Coxiella burnetii in Humans and Ticks in Rural Senegal

Q fever is a zoonotic disease known since 1937. The disease may be severe, causing pneumonia, hepatitis and endocarditis. Q fever agent has been described as a possible biological weapon. Animals—especially domestic cows, goats and sheep—are considered reservoirs for this infection. They are capable of sustaining the infection for long periods and excreting viable bacteria, infecting other animals and, occasionally, humans. Here we studied the distribution of Q fever in a poorly studied region, Senegal. We studied the agent of Q fever both in ticks parasitizing domestic animals and in humans (antibodies in serum, bacteria in feces, saliva and milk). We found from the studied regions the bacterium is highly prevalent in rural Senegal. Up to 37.6% of five different and most prevalent tick species may carry the bacterium. Humans living in such areas, as other mammals, may occasionally excrete Q fever agent through feces and milk

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

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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).</p> <p>Results</p> <p>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; <it>p </it>= 0.04). At the end of the transmission season, malaria parasitaemia prevalence was lower in communities with IPTc + HMM (2.05% versus 4.6% <it>p </it>= 0.03). Adjusted for age groups, sex, <it>Plasmodium falciparum </it>carriage and prevalence of malnutrition, IPTc + HMM showed a significant protective effect against anaemia (aOR = 0.59; 95% CI 0.42-0.82; <it>p </it>= 0.02).</p> <p>Conclusion</p> <p>Combining IPTc and HMM can provide significant additional benefit in preventing clinical episodes of malaria as well as anaemia among children in Senegal.</p

Short Report : Throat swab samples for diagnosis of Q fever

Oropharyngeal swabs collected from patients with Q fever from France and from febrile patients from Senegal were tested by molecular assays for Coxiella burnetii. One positive result (0.08%) occurred for only one patient with acute Q fever. Throat swabs cannot replace blood serum samples as diagnostic tools for Q fever

Identification of rickettsial pathogens in ixodid ticks in northern Senegal

The spotted fevers, caused by the Rickettsia bacteria, are a group of emerging diseases that are responsible for significant human morbidity. In Africa, the distribution of different species of Rickettsia in their tick vectors is poorly studied. We have collected 1169 hard ticks from 5 different species in the northern Senegal, close to the Saharan border. In a far northern collection site, corresponding to the Rickettsia africae distribution area, we collected three Amblyomma variegatum ticks infected by R. africae. Rickettsia africae was also identified in a Hyalomma marginatum rufipes tick, which may represent the secondary host for the pathogen. Rickettsia aeschlimannii was identified in H. m. rufipes, Rhipicephalus evertsi evertsi, and Hyalomma impeltatum ticks

The correlation of Q fever and Coxiella burnetii DNA in household environments in rural Senegal

During 2008-2011, we tested 874 blood samples from febrile patients who had a fever >37.5 degrees C, and 207 surface samples in households for Coxiella burnetii DNA in two rural Senegalese villages (Dielmo and Ndiop). Fisher's exact test and Spearman's correlation coefficient were used for statistical analysis. We identified four blood samples as positive for Coxiella burnetii DNA. The prevalence of Q fever in all tested samples was 0.46% in the two villages. C. burnetii DNA was also found in 7.5% of the dust samples in Ndiop, and in 0.9% in Dielmo; the prevalence in households was 22.6% in Ndiop and 2.6% in Dielmo. In Ndiop we found a weak correlation between positive environmental samples and the occurrence of the disease. Our findings show an association of environmental C. burnetii with human Q fever cases in a recently identified endemic area in rural Senegal

Description of "yaaf", the vesicular fever caused by acute Rickettsia felis infection in Senegal

Rickettsiosis caused by Rickettsia felis is an emerging infection in Africa and may account for 3-4% of ambulatory febrile fevers. We report herein a case of R. felis infection, for which we propose the name "yaaf", meaning vesicle, in an 8-month-old girl who was diagnosed in the field by real-time PCR analysis of a skin lesion; these PCR analysis was performed at a local experimental point-of-care laboratory. The clinical presentation was polymorphous skin lesions, including papules, vesicles, erosions and ulcers. The patient did not produce antibodies against Rickettsia. We suggest that this disease may be a primary infection caused by R. felis

Molecular identification of pathogenic bacteria in eschars from acute febrile patients, Senegal

Fever caused by Rickettsia fells was recently shown to play an important role in infectious diseases morbidity in sub-Saharan Africa. We collected 68 cotton swabs from fever-associated eschars in four different regions of Senegal. In 5 of 68 eschar samples (7.4%), we have identified DNA from R. felis. In 49 of 68 eschar samples (72.1%), we have identified DNA from Staphylococcus aureus. In 35 of 68 eschar samples (51.5%), we have identified DNA from Streptococcus pyogenes, and in 4 of 68 eschar samples (5.9%), we have identified DNA from Streptococcus pneumoniae. In 34 cases, S. aureus was found together with S. pyogenes. DNA from R. fells was also found in swabs from the skin of the healthy Senegalese villagers (3 of 60; 5%) but not French urbanites. The presence of S. aureus and S. pyogenes was significantly associated with the presence of eschars in febrile patients compared with the healthy skin from the control group. Finally, we confirmed that Senegal is an endemic region for R. fells, which is found in both eschars and healthy skin swabs