Seroepidemiological Reconstruction of Long-term Chikungunya Virus Circulation in Burkina Faso and Gabon.

Chikungunya virus (CHIKV) is a major public health concern worldwide. However, infection levels are rarely known, especially in Africa. We recruited individuals from Ouagadougou, Burkina Faso and Lambaréné, Gabon (age range, 1-55 years), tested their blood for CHIKV antibodies, and used serocatalytic models to reconstruct epidemiological histories. In Ouagadougou, 291 of 999 (29.1%) individuals were seropositive, ranging from 2% among those aged <10 years to 66% in those aged 40-55 years. We estimated there were 7 outbreaks since the 1970s but none since 2001, resulting in 600 000 infections in the city, none of which were reported. However, we could not definitively conclude whether infections were due to CHIKV or o'nyong-nyong, another alphavirus. In Lambaréné, 117 of 427 (27%) participants were seropositive. Our model identified a single outbreak sometime since 2007, consistent with the only reported CHIKV outbreak in the country. These findings suggest sporadic outbreaks in these settings and that the burden remains undetected or incorrectly attributed.

Pneumococcal Carriage in Burkina Faso After 13-Valent Pneumococcal Conjugate Vaccine Introduction: Results From 2 Cross-sectional Population-Based Surveys.

BACKGROUND: Burkina Faso, a country in Africa's meningitis belt, introduced 13-valent pneumococcal conjugate vaccine (PCV13) in October 2013, with 3 primary doses given at 8, 12 and 16 weeks of age. To assess whether the new PCV13 program controlled pneumococcal carriage, we evaluated overall and serotype-specific colonization among children and adults during the first 3 years after introduction. METHODS: We conducted 2 population-based, cross-sectional, age-stratified surveys in 2015 and 2017 in the city of Bobo-Dioulasso. We used standardized questionnaires to collect sociodemographic, epidemiologic, and vaccination data. Consenting eligible participants provided nasopharyngeal (all ages) and oropharyngeal (≥5 years only) swab specimens. Swab specimens were plated onto blood agar either directly (2015) or after broth enrichment (2017). Pneumococci were serotyped by conventional multiplex polymerase chain reaction. We assessed vaccine effect by comparing the proportion of vaccine-type (VT) carriage among colonized individuals from a published baseline survey (2008) with each post-PCV survey. RESULTS: We recruited 992 (2015) and 1005 (2017) participants. Among children aged <5 years, 42.8% (2015) and 74.0% (2017) received ≥2 PCV13 doses. Among pneumococcal carriers aged <1 year, VT carriage declined from 55.8% in 2008 to 36.9% in 2017 (difference, 18.9%; 95% confidence interval, 1.9%-35.9%; P = .03); among carriers aged 1-4 years, VT carriage declined from 55.3% to 31.8% (difference, 23.5%; 6.8%-40.2%; P = .004); and among participants aged ≥5 years, no significant change was observed. CONCLUSION: Within 3 years of PCV13 implementation in Burkina Faso, we documented substantial reductions in the percentage of pneumococcal carriers with a VT among children aged <5 years, but not among persons aged ≥5 years. More time, a change in the PCV13 schedule, or both, may be needed to better control pneumococcal carriage in this setting.

Antibody Persistence at the Population Level 5 Years After Mass Vaccination With Meningococcal Serogroup A Conjugate Vaccine (PsA-TT) in Burkina Faso: Need for a Booster Campaign?

Background: In Burkina Faso, serogroup A meningococcal (NmA) conjugate vaccine (PsA-TT, MenAfriVac) was introduced through a mass campaign in children and adults in December 2010. Similar to a serological survey in 2011, we followed population-level antibody persistence for 5 years after the campaign and estimated time of return to previously-published pre-vaccination levels. Methods: We conducted 2 cross-sectional surveys in 2013 and early 2016, including representative samples (N = 600) of the general population of Bobo-Dioulasso, Burkina Faso. Serum bactericidal antibody titers (rabbit complement) were measured against NmA reference strain F8236 (SBA-ref), NmA strain 3125 (SBA-3125), and NmA-specific immunoglobulin G (IgG) concentrations. Results: During the 2016 survey, in different age groups between 6 and 29 years, the relative changes in geometric means compared to 2011 values were greater among younger age groups. They were between -87% and -43% for SBA-ref; -99% and -78% for SBA-3125; and -89% and -63% for IgG. In linear extrapolation of age-specific geometric means from 2013 to 2016, among children aged 1-4 years at the time of the PsA-TT campaign, a return to pre-vaccination levels should be expected after 12, 8, and 6 years, respectively, according to SBA-ref, SBA-3125, and IgG. Among older individuals, complete return to baseline is expected at the earliest after 11 years (SBA-ref and SBA-3125) or 9 years (IgG). Conclusions: Based on SBA-3125, a booster campaign after 8 years would be required to sustain direct immune protection for children aged 1-4 years during the PsA-TT campaign. Antibodies persisted longer in older age groups.

Meningococcal Seroepidemiology 1 Year After the PsA-TT Mass Immunization Campaign in Burkina Faso.

BACKGROUND: A group A meningococcal (MenA) conjugate vaccine, PsA-TT (MenAfriVac), was introduced in Burkina Faso via mass campaigns between September and December 2010, targeting the 1- to 29-year-old population. This study describes specific antibody titers in the general population 11 months later and compares them to preintroduction data obtained during 2008 using the same protocol. METHODS: During October-November 2011, we recruited a representative sample of the population of urban Bobo-Dioulasso aged 6 months to 29 years, who underwent standardized interviews and blood draws. We assessed anti-MenA immunoglobulin G (IgG) concentrations (n = 200) and, using rabbit complement, serum bactericidal antibody (SBA) titers against 2 group A strains: reference strain F8238 (SBAref) (n = 562) and strain 3125 (SBA3125) (n = 200). RESULTS: Among the 562 participants, 481 (86%) were aged ≥23 months and had been eligible for the PsA-TT campaign. Among them, vaccine coverage was 86.3% (95% confidence interval [CI], 82.7%-89.9%). Prevalence of putatively protective antibodies among vaccine-eligible age groups was 97.3% (95% CI, 95.9%-98.7%) for SBAref titers ≥128, 83.6% (95% CI, 77.6%-89.7%) for SBA3125 ≥128, and 84.2% (95% CI, 78.7%-89.7%) for anti-MenA IgG ≥2 µg/mL. Compared to the population aged 23 months to 29 years during 2008, geometric mean titers of SBAref were 7.59-fold higher during 2011, 51.88-fold for SBA3125, and 10.56-fold for IgG. CONCLUSIONS: This study shows high seroprevalence against group A meningococci in Burkina Faso following MenAfriVac introduction. Follow-up surveys will provide evidence on the persistence of population-level immunity and the optimal vaccination strategy for long-term control of MenA meningitis in the African meningitis belt.

Antipneumococcal seroprevalence and pneumococcal carriage during a meningococcal epidemic in Burkina Faso, 2006.

BACKGROUND: To better understand the high incidence of pneumococcal meningitis in the African meningitis belt, we conducted a pneumococcal seroprevalence study during a meningococcal meningitis epidemic in Western Burkina Faso, March 2006. METHODS: In 3 villages experiencing epidemics, we included 624 healthy persons (1-39 years) by cluster sampling. We determined pneumococcal serum immunoglobulin G (IgG) antibody concentrations against 12 serotypes contained in 13-valent pneumococcal conjugate vaccine, and evaluated determinants for IgG ≥ 0.35 µg/mL by multivariate logistic regression. RESULTS: The percentage of subjects with serotype-specific IgG concentrations ≥0.35 µg/mL increased with age and was similar for the different serotypes: it was 20%-43% among 1-4-year-olds and 56%-90% among 20-39-year-olds. Prevalence of IgG ≥ 0.35 µg/mL against serotype 1 was up to 71% after age 10 years. During multivariate analyses, determinants of IgG concentrations ≥0.35 µg/mL varied by serotype; for 5 and 6 serotypes, respectively, female sex (around 2-fold increased odds) and cigarette smoking (about 5-fold reduced odds) predicted elevated titers. CONCLUSIONS: Despite a substantially higher historical pneumococcal meningitis incidence in Burkina Faso, the general population has an antibody seroprevalence against 12 pneumococcal serotypes similar to that reported from the United Kingdom. The role of putatively protective antibody seroprevalence in preventing pneumococcal meningitis in the meningitis belt requires more thorough evaluation.

Voluntary HIV testing and risky sexual behaviours among health care workers: a survey in rural and urban Burkina Faso.

BACKGROUND: Voluntary counselling and testing (VCT) together with a safe sexual behaviour is an important preventive strategy in the control of HIV. Although Health care workers (HCWs) are critical in the response to HIV, little is known about VCT and high risk behaviours (HRB) among this group in West Africa. This study aims to assess the prevalence of VCT and HRB among HCWs in Burkina Faso. METHODS: We collected data through a questionnaire in urban areas (Ouagadougou and Bobo-Dioulasso) and rural areas (Poni and Yatenga) among HCWs from 97 health care facilities. Urine samples were collected, screened for HIV using a Calypte(®) test kit and confirmed by Western Blot. Multiple logistic regression analysis was performed to identify factors associated with the use of VCT services and with high-risk sex behaviour. RESULTS: About 92.5% of eligible HCWs participated (1570 out of 1697). Overall, 38.2% of them (34.6% of women and 42.6% of men) had ever used VCT services. About 40% of HCWs reported that fear of knowing the test result was the main reason for not doing the HIV test. Male HCWs (p = 0.001), laboratory workers (p < 0.001), those having two years or more experience (p = 0.03), and those who had multiple partners (p = 0.001) were more likely to have tested for HIV. One fifth of HCWs reported multiple partners. Of these, thirteen percent did not use condoms. HCWs who had multiple partners were significantly more likely to be men, single, living in rural areas, and under the age of 29 years. CONCLUSION: VCT was still very low among HCWs in Burkina Faso, while HRB was high.These findings suggest that 'HCW-friendly' VCT centres should be implemented, securing confidentiality among colleagues. In addition, refreshment courses on HIV risk reduction, counselling and testing are certainly required during the professional career of HCWs.

Study of a localized meningococcal meningitis epidemic in Burkina Faso: incidence, carriage, and immunity.

BACKGROUND: To better understand localized meningococcal meningitis epidemics, we evaluated a serogroup A (NmA) epidemic in Burkina Faso by surveillance, carriage, and seroprevalence studies. METHODS: During March-April 2006, cerebrospinal fluid samples from patients suspected to have meningitis in 3 epidemic villages were analyzed by culture or polymerase chain reaction. We assessed meningococcal carriage and serogroup-specific serum bactericidal antibody titers with baby rabbit complement (rSBA) in a representative population sample (N = 624; age range, 1-39 years). A serogroup A/C polysaccharide vaccine campaign occurred in parallel. RESULTS: Cumulative incidence of Nm meningitis was 0.45% and varied among villages (0.08%-0.91%). NmA carriage prevalence was 16% without variation by vaccination status. NmA carriage and anti-NmA seroprevalence varied by village and incidence. In the 2 villages with highest incidence and seroprevalence, presence of rSBA titers ≥8 was associated with NmA carriage (odds ratio [OR], 9.33 [95% confidence interval {CI}, 1.90-45.91]) and vaccination ≤4 days earlier (OR, 0.10 [95% CI, .03-.32]). Visibly purulent or Nm meningitis was significantly associated with recent flulike symptoms and exposure to kitchen smoke (risk ratios >15). CONCLUSIONS: A surge of NmA carriage may be involved in the development of meningococcal epidemics and rapidly increase anti-NmA seroprevalence. Flulike infection and kitchen smoke may contribute to the strength of epidemics.

Evaluation of Adherence of Health-Care Workers to Integrated Management of Childhood Illness Guidelines in the Context of the Free Care Program in Burkina Faso.

To reduce child mortality in children younger than 5 years, Burkina Faso has been offering free care to this population of children since 2016. The free care program is aligned with the Integrated Management of Childhood Illness (IMCI) guidelines. Given that the number of studies that evaluated the competence of health-care workers (HCWs) during the free care program was limited, we assessed the adherence level of HCWs to the IMCI guidelines in the context of free care. This was a secondary data analysis. Data were obtained from a cross-sectional study conducted from July to September 2020 in 40 primary health-care centers and two district hospitals in the Hauts-Bassins region in Burkina Faso. Our analysis included 419 children younger than 5 years old who were consulted according to IMCI guidelines. Data were collected through direct observation using a checklist. The overall score of adherence of HCWs to IMCI guidelines was 57.8% (95% CI, 42.6-73.0). The mean adherence score of the evaluation of danger signs was 71.9% (95% CI, 58.7-85.1). The mean adherence score of following IMCI guidelines was significantly greater in boys (54.2%) compared with girls (44.6%; P < 0.001). Adherence scores of the performance of different IMCI tasks were significantly different across HCW categories. The overall adherence of HCWs to IMCI guidelines in the context of free care was greater than the adherence reported before the implementation of free care in Burkina Faso. However, this assessment needs to be performed nationwide to capture the overall adherence of HCWs to IMCI guidelines in the context of the free care program.

Low seroprevalence of syphilis in Burkina Faso.

BACKGROUND: Little information is available on the epidemiology of syphilis in West Africa, where this infection is routinely screened in antenatal clinics to prevent congenital infection. In order to inform control programmes, the burden of active syphilis was estimated among pregnant women and adults in Burkina Faso. METHODS: This study enrolled 2136 pregnant women from 98 healthcare facilities and 1679 consenting women and men from the general population of Ouagadougou, the capital city. After a face-to-face interview on demographic characteristics, blood samples were collected and tested for syphilis. Active syphilis was defined by a dually positive result on rapid plasma reagin and Treponema pallidum haemagglutination antibody tests. RESULTS: The overall seroprevalence of active syphilis was 1.7% (95% CI 1.3 to 2.2), with similar rates between women (1.2%, 95% CI 0.7 to 2.3) and men (1.8%, 95% CI 1.0 to 3.0) in Ouagadougou, and a trend for higher prevalence among pregnant women from semi-urban areas (2.2%, 95% CI 1.0 to 4.5) compared with rural areas (1.7%, 95% CI 1.2 to 2.4, p = 0.06). The prevalence tended to be higher among women aged 20-24 years (2.6%, 95% CI 1.3 to 7.6) and men aged 30-34 years (3.9%, 95% CI 0.8 to 11.0) than at other ages. However, age, marital status, location and education were not associated with syphilis. CONCLUSION: The low prevalence of syphilis among pregnant women and the adult general population is very encouraging but should not challenge the amount of resources dedicated to sexually transmitted infection and HIV prevention.

Epidemiology of herpes simplex virus type 2 infection in rural and urban Burkina Faso.

BACKGROUND: Herpes simplex virus type 2 (HSV-2) infection enhances human immunodeficiency virus (HIV) susceptibility and may increase sexual transmission, but few data on HSV-2 prevalence are available from West Africa. The main objective of this study was to describe the prevalence and determinants of HSV-2 among adults in urban and rural Burkina Faso. METHODS: We conducted (i) a 2-stage clustered population-based survey among adults aged 15 to 49 years in Ouagadougou (N = 883 women and 791 men), the capital city of Burkina Faso, and (ii) a cross-sectional study among attendees (N = 2018) of all 98 antenatal clinics from 4 provinces of the country. HSV-2 infection was diagnosed using a specific IgG2 enzyme-linked immunosorbent assay test (Kalon). RESULTS: The prevalence of HSV-2 among pregnant women was 18.0% (95% confidence interval (CI): 16.3%-19.7%), with a trend for lower rates in rural (17.3%; CI: 15.5%-19.2%) versus semiurban areas (21.4%; CI: 17.2%-26.2%) (P = 0.08), whereas the prevalence of HSV-2 was 23.7% (CI: 20.9%-26.6%) among women in Ouagadougou (N = 883), and 15.3% (CI: 12.9%-18.0%) among men (N = 791). Using multivariable logistic regression analysis among women, older age, being married, contraceptives, bacterial vaginosis (BV), and HIV infection were significantly associated with HSV-2 infection. Among men, only increased age and HIV were independently associated with HSV-2. CONCLUSION: The prevalence of HSV-2 infection was high among young women, including in rural areas, with a strong association with BV. Therefore, rural areas should not be neglected in prevention programs. New potent BV, hormonal contraceptives, and HSV control strategies may be helpful for HIV control.

Knowledge, beliefs and practices regarding prevention of bacterial meningitis in Burkina Faso, 5 years after MenAfriVac mass campaigns.

BACKGROUND: To adapt communications concerning vaccine prevention, we studied knowledge, beliefs and practices around meningitis risk and prevention in a young adult population in Burkina Faso in 2016, 5 years after the MenAfriVac® mass campaign and one year before the vaccine's inclusion in the infant immunization schedule. METHODS: In a representative sample of the population aged 15 to 33 years (N = 220) in Bobo-Dioulasso, Burkina Faso, study nurses administered a standardized paper questionnaire consisting of predominantly open questions, collecting information on meningitis risk factors and prevention, and on exposure to dry air and kitchen fire smoke. We identified themes and analyzed their frequency. We created a meningitis knowledge score (range 0 to 4) based on pre-defined best responses and analyzed the determinants of knowledge score levels ≥2 (basic score) and ≥3 (high score) using multivariate logistic regression. RESULTS: Biomedically supported facts and good practices were known by the majority of participants (eg vaccine prevention, 84.5%). Younger women aged 15-20 years had a higher frequency of low scores <2 (17.0%) compared to older women aged 21-33 years (6.3%) and men of both age groups (3.8%). Junior secondary School attendance explained the differences between the two groups of women, the gender gap for the older, but not the young women, and explained score differences among young women. Local understandings and practices for risk and prevention were commonly reported and used (risk from unripe mango consumption and prevention through nasal application of shea nut butter). DISCUSSION: This study shows a gender gap in knowledge of meningitis risk and prevention, largely due to education-level inequalities. Women below 21 years had particularly low levels of knowledge and may need interventions outside schools and perinatal care. Our study suggests a strong adherence to local understandings of and practices around meningitis risk and prevention, which should be taken into account by vaccination promotion.

Serotyping pneumococcal meningitis cases in the African meningitis belt by use of multiplex PCR with cerebrospinal fluid.

We reformulated a multiplex PCR algorithm for serotyping of pneumococcal meningitis directly on cerebrospinal fluid (CSF). Compared to established methods on isolates, CSF-based PCR had at least 80% sensitivity and 100% specificity. In regional meningitis surveillance, CSF-based PCR increased the serotype information yield from 40% of cases (isolate testing) to 90%.

African meningitis belt pneumococcal disease epidemiology indicates a need for an effective serotype 1 containing vaccine, including for older children and adults.

BACKGROUND: Pneumococcal conjugate vaccine strategies in GAVI-eligible countries are focusing on infant immunization but this strategy may not be optimal in all settings. We aimed to collect all available population based data on pneumococcal meningitis throughout life in the African meningitis belt and then to model overall meningitis risk to help inform vaccine policy. METHODS: After a systematic review of literature published from 1970 through the present, we found robust population-based Streptococcus pneumoniae (Sp) meningitis data across age strata for four African meningitis belt countries that included 35 surveillance years spanning from 1970 to 2005. Using these data we modeled disease risk for a hypothetical cohort of 100,000 persons followed throughout life. RESULTS: Similar to meningococcal meningitis, laboratory-confirmed pneumococcal meningitis was seasonal, occurring primarily in the dry season. The mean annual Sp meningitis incidence rates were 98, 7.8 to 14, and 5.8 to 12 per 100,000 among persons <1, 1 through 19, and 20 to 99 years of age, respectively, which (in the absence of major epidemics) were higher than meningococcal meningitis incidences for persons less than 1 and over 20 years of age. Mean Sp meningitis case fatality ratios (CFR) among hospitalized patients ranged from 36-66% depending on the age group, with CFR exceeding 60% for all age groups beyond 40 years; depending on the age group, Sp meningitis mortality incidences were 2 to 12-fold greater than those for meningococcal meningitis. The lifetime risks of pneumococcal meningitis disease and death were 0.6% (1 in 170) and 0.3% (1 in 304), respectively. The incidences of these outcomes were highest among children age <1 year. However, the cumulative risk was highest among persons age 5 to 59 years who experienced 59% of pneumococcal meningitis outcomes. After age 5 years and depending on the country, 59-79% of meningitis cases were caused by serotype 1. CONCLUSIONS: In the African meningitis belt, Sp is as important a cause of meningitis as Neisseria meningitidis, particularly among older children and working age adults. The meningitis belt population needs an effective serotype 1 containing vaccine and policy discussions should consider vaccine use outside of early childhood.

Incidence, seasonality, age distribution, and mortality of pneumococcal meningitis in Burkina Faso and Togo.

Streptococcus pneumoniae causes a substantial proportion of meningitis cases in the African meningitis belt; however, few reports exist to quantify its burden and characteristics. We conducted population-based and sentinel hospital surveillance of acute bacterial meningitis among persons of all ages in Burkina Faso and Togo in 2002-2006. S. pneumoniae and other organisms were identified by culture, polymerase chain reaction, or detection of antigen in cerebrospinal fluid (CSF). Information was collected on 2843 patients with suspected acute bacterial meningitis. CSF specimens were collected from 2689 (95%) of the patients; of these 2689, 463 (17%) had S. pneumoniae identified, 234 (9%) had Haemophilus influenzae type b identified, and 400 (15%) had Neisseria meningitidis identified. Of the 463 cases of S. pneumoniae meningitis, 99 (21%) were aged <1 year, 71 (15%) were aged 1-4 years, 95 (21%) were aged 5-14 years, and 189 (41%) were aged >or=15 years (age was unknown for 9 [2%]). In Burkina Faso, the annual incidence rate of pneumococcal meningitis was 14 cases per 100,000 persons, with annual incidence rates of 77, 33, 10, and 11 cases per 100,000 persons aged <1 year, <5 years, 5-14 years, and >or=15 years, respectively. The case-fatality ratio for S. pneumoniae meningitis was 47% (range for age groups, 44%-52%), and 53% of deaths occurred among those aged >5 years. S. pneumoniae meningitis had an epidemic pattern similar to that of N. meningitidis meningitis. Of 48 isolates tested for serotype, 18 were from children aged <5 years; of these 18, 3 isolates (17%) each were serotypes 1, 2, and 5, and 5 isolates (28%) were serotype 6A. The 7-, 10-, and 13-valent pneumococcal conjugate vaccines would cover 6%, 39%, and 67% of serotypes identified among children aged <5 years, respectively. Of the 30 serotypes identified for patients aged >or=5 years, 18 (60%) were serotype 1, whereas no other serotype constituted >10%. The 7-, 10-, and 13-valent vaccines would cover 7%, 70%, and 77% of serotypes. Epidemic pneumococcal meningitis in the African meningitis belt countries of Burkina Faso and Togo is common, affects all age groups, and is highly lethal. On the basis of a modest number of isolates from a limited area that includes only meningitis cases, 7-valent pneumococcal conjugate vaccine might have only a limited and short-term role. By contrast, the proposed 10- and 13-valent vaccines would cover most of the identified serotypes. To better inform vaccine policy, continued and expanded surveillance is essential to document serotypes associated with pneumonia, changes in serotype distribution across time, and the impact of vaccine after vaccine introduction.

Immunogenicity and Reactogenicity of 13-Valent Pneumococcal Conjugate Vaccine Among Infants, Toddlers, and Children in Western Burkina Faso: Results From a Clinical Trial of Alternative Immunization Schedules.

BACKGROUND: Many African countries have introduced pneumococcal conjugate vaccine (PCV) into their routine immunization program to reduce the burden of morbidity and death that results from Streptococcus pneumoniae infection, yet immunogenicity and reactogenicity data from the region are limited for the 2 available PCV products. METHODS: We conducted a randomized trial of 13-valent PCV (PCV13) in Bobo-Dioulasso, Burkina Faso. Infants received 3 doses of PCV at 6, 10, and 14 weeks of age or at 6 weeks, 14 weeks, and 9 months of age; toddlers received 2 doses 2 months apart or 1 dose beginning at 12 to 15 months of age; and children received 1 dose between 2 and 4 years of age. We measured each participant's serotype-specific serum immunoglobulin G concentration and opsonophagocytic activity before and after vaccination. For each age group, we compared immune responses between study arms and between the standard schedule in our study and the PCV13-licensing trials. RESULTS: In total, 280 infants, 302 toddlers, and 81 children were assigned randomly and underwent vaccination; 268, 235, and 77 of them completed follow-up, respectively. PCV13 resulted in low reactogenicity in all the study arms. The vaccine elicited a strong primary immune response in infants after 2 or more doses and in children aged 1 to 4 years after 1 dose. Infants who received a booster dose exhibited a robust memory response. Immunogenicity was higher than or comparable to that observed in the PCV13-licensing trials for a majority of serotypes in all 3 age groups. CONCLUSIONS: PCV13 has a satisfactory immunogenicity and reactogenicity profile in this population. Our findings will help support decision making by countries regarding their infant and catch-up vaccination schedules.

A multi-country study of the economic burden of dengue fever based on patient-specific field surveys in Burkina Faso, Kenya, and Cambodia.

BACKGROUND: Dengue fever is a rapidly growing public health problem in many parts of the tropics and sub-tropics in the world. While there are existing studies on the economic burden of dengue fever in some of dengue-endemic countries, cost components are often not standardized, making cross-country comparisons challenging. Furthermore, no such studies have been available in Africa. METHODS/PRINCIPAL FINDINGS: A patient-specific survey questionnaire was developed and applied in Burkina Faso, Kenya, and Cambodia in a standardized format. Multiple interviews were carried out in order to capture the entire cost incurred during the period of dengue illness. Both private (patient's out-of-pocket) and public (non-private) expenditure were accessed to understand how the economic burden of dengue is distributed between private and non-private payers. A substantial number of dengue-confirmed patients were identified in all three countries: 414 in Burkina Faso, 149 in Kenya, and 254 in Cambodia. The average cost of illness for dengue fever was $26 (95% CI $23-$29) and $134 (95% CI $119-$152) per inpatient in Burkina Faso and Cambodia, respectively. In the case of outpatients, the average economic burden per episode was $13 (95% CI $23-$29) in Burkina Faso and $23 (95% CI $19-$28) in Kenya. Compared to Cambodia, public contributions were trivial in Burkina Faso and Kenya, reflecting that a majority of medical costs had to be directly borne by patients in the two countries. CONCLUSIONS/SIGNIFICANCE: The cost of illness for dengue fever is significant in the three countries. In particular, the current study sheds light on the potential economic burden of the disease in Burkina Faso and Kenya where existing evidence is sparse in the context of dengue fever, and underscores the need to achieve Universal Health Coverage. Given the availability of the current (CYD-TDV) and second-generation dengue vaccines in the near future, our study outcomes can be used to guide decision makers in setting health policy priorities.

Hepatitis E Virus Infections among Patients with Acute Febrile Jaundice in Burkina Faso.

Hepatitis E virus infection is a significant public health problem in many parts of the world including Africa. We tested serum samples from 900 patients in Burkina Faso presenting with febrile icterus. They all tested negative for yellow fever, but those from 23/900 (2.6%) patients contained markers of acute HEV infection (anti-HEV IgM and HEV RNA positive). Genotyping indicated that 14 of the strains were HEV genotype 2b. There was an overall HEV IgG seroprevalence of 18.2% (164/900). In a bivariate analysis, the factors linked to HEV exposure were climate and patient age. Older patients and those living in arid regions were more likely to have HEV infection. HEV genotype 2b circulating only in humans can be involved in some acute febrile icterus cases in Burkina Faso. Better access to safe water, sanitation, and improved personal hygiene should improve control of HEV infection in this country.

Bacterial vaginosis among pregnant women in Burkina Faso.

OBJECTIVES: Bacterial vaginosis (bv) is a common cause of abnormal or altered vaginal discharge in women of childbearing age. Its association with obstetric and gynecologic complications and HIV are increasingly recognized. Few population-based surveys of BV have been conducted in Africa. The objective of the study was to examine the role of genital infections including Herpes simplex virus type 2 (HSV-2) and demographic factors on the prevalence of BV among pregnant women in Burkina Faso. METHODS: Consenting pregnant women from Burkina Faso answered a face-to-face interview on their demographic characteristics. Then, genital and blood swabs were collected and tested for BV and other genital infections. Univariable and multivariable models were used to investigate the risk factors of BV. RESULTS: Among the 2133 women included in the analyses (over 2284 enrolled), the prevalence of BV was 6.4% [95% confidence interval (CI), 5.5%-7.6%], ranging from 3% to 12% between regions. In multivariable analyses, HSV-2 [odds ratio (OR), 1.64; 95% CI 1.04-2.59) was the only genital infection that remained significantly associated with BV. Other factors related to BV were history of abortion (OR, 1.57; 95% CI, 1.01-2.43) and geographical origin. HIV infection (OR, 1.98; 95% CI, 0.90-5.20) and polygamy (OR, 1.48; 95% CI, 1.00-2.36) tended to be associated with BV without reaching statistical significance. CONCLUSION: The prevalence of BV among pregnant women was lower than expected, with large geographical disparities. Our data confirm the potential interaction between BV and HSV-2.

Association of respiratory tract infection symptoms and air humidity with meningococcal carriage in Burkina Faso.

OBJECTIVES: To evaluate risk factors for meningococcal carriage and carriage acquisition in the African meningitis belt, comparing epidemic serogroup A (NmA) to non-epidemic serogroups. METHODS: During the non-epidemic meningitis season of 2003, pharyngeal swabs were taken at five monthly visits in a representative population sample (N = 488) of Bobo-Dioulasso, Burkina Faso (age 4-29 years) and analysed by culture. Standardized questionnaires were administered. In 2006, a similar study was performed in 624 individuals (age 1-39 years) during an NmA meningitis epidemic. We evaluated serogroup-specific risk factors for carriage, carriage acquisition and clearance using multivariate logistic and Poisson regression, and a Cox proportional hazard model. RESULTS: The prevalence of NmA carriage (current or recent pharyngitis or rhinitis) was 16% (31%) vs. 0% (9%) in the epidemic vs. the hyperendemic setting. During the epidemic situation, NmA carriage was significantly associated with recent sore throat (adjusted odds ratio (OR), 3.41) and current rhinitis (OR 2.65). During the non-epidemic meningitis season in 2003, air humidity (20-39% and >or=40%, compared to <20%) during the month before swabbing was significantly and positively associated with carriage acquisition of non-groupable meningococci (OR 2.18 and 1.55) and inversely with carriage clearance (hazard ratio 0.61 and 0.27, respectively). CONCLUSION: Respiratory tract infections may increase meningococcal carriage, and thus contribute to epidemic risk, in addition to seasonality in the meningitis belt. Humid climate may favour carriage of unencapsulated meningococci. These findings may help identifying interventions against epidemic and hyperendemic meningococcal meningitis due to non-vaccine serogroups.

Continuation of subcutaneous or intramuscular injectable contraception when administered by facility-based and community health workers: findings from a prospective cohort study in Burkina Faso and Uganda.

OBJECTIVE: The aim of this study was to examine continuation of subcutaneous and intramuscular depot medroxyprogesterone acetate (DMPA-SC and DMPA-IM) when administered by facility-based health workers in Burkina Faso and Village Health Teams (VHTs) in Uganda. STUDY DESIGN: Participants were family planning clients of health centers (Burkina Faso) or VHTs (Uganda) who had decided to initiate injectable use. Women selected DMPA-SC or DMPA-IM and study staff followed them for up to four injections (providing 12 months of pregnancy protection) to determine contraceptive continuation. Study staff interviewed women at their first injection (baseline), second injection, fourth injection and if they discontinued either product. RESULTS: Twelve-month continuation in Burkina Faso was 50% for DMPA-SC and 47.4% for DMPA-IM (p=.41, N=990, 492 DMPA-SC and 498 DMPA-IM). Twelve-month continuation in Uganda was 77.8% for DMPA-SC and 77.4% for DMPA-IM (p=.85, N=1224, 609 DMPA-SC and 615 DMPA-IM). Reasons for discontinuation of DMPA across groups in Burkina Faso included side effects (90/492, 18.3%), being late for injection (68/492, 13.8%) and refusal of spouse (51/492, 10.4%). Reasons for discontinuation in Uganda included being late for injection (65/229, 28.4%), received from non-VHT (50/229, 21.8%) and side effects (34/229, 14.8%). Increased age (adjusted hazard ratio=0.98, p=.01) and partner acceptance of family planning (adjusted hazard ratio=0.48, p<.001) had protective effects against discontinuation in Burkina Faso; we did not find statistically significant variables in Uganda. CONCLUSIONS: There is no difference in 12-month continuation (through four injections) between DMPA-SC and DMPA-IM whether from facility-based health workers in Burkina Faso or VHTs in Uganda. Continuation was higher through community-based distribution in Uganda than health facilities in Burkina Faso. IMPLICATIONS: The subcutaneous formulation of depot medroxyprogesterone acetate (DMPA-SC) is increasingly available in Family Planning 2020 countries. Use of DMPA-SC does not appear to change continuation relative to traditional intramuscular DMPA. Growing evidence of DMPA-SC's suitability for community-based distribution and self-injection may yield indirect benefits for contraceptive continuation and help reach new users.