Search

Nontyphoidal Salmonella (NTS) are the leading cause of foodborne infections worldwide and a major cause of bloodstream infections in infants and HIV-infected adults in sub-Saharan Africa (SSA). Salmonella Typhimurium (serogroup B) and Salmonella Enteritidis (serogroup D) are the most common serovars in this region. However, data describing rarer invasive NTS serovars, particularly those belonging to serogroups C1 and C2, circulating in SSA are lacking. We previously conducted systematic blood culture surveillance on pediatric patients in Bamako, Mali, from 2002 to 2014, and the results showed that serovars Typhimurium and Enteritidis accounted for 32% and 36% of isolates, respectively. Here, we present data on 27 Salmonella serogroup C1 strains that were isolated during this previous study. The strains were typed by serum agglutination and multilocus sequence typing (MLST). Sixteen strains were Salmonella Paratyphi C, four were Salmonella Colindale, and two were Salmonella Virchow. Interestingly, five strains were identified as the very rare Salmonella Brazzaville using a combination of serum agglutination and flagellin gene typing. Phenotypic characterization showed that Salmonella Brazzaville produced biofilm and exhibited catalase activity, which were not statistically different from the gastroenteritis-associated Salmonella Typhimurium sequence type (ST) 19. All tested Salmonella Paratyphi C strains were poor biofilm producers and showed significantly less catalase activity than Salmonella Typhimurium ST19. Overall, our study provides insight into the Salmonella serogroup C1 serovars that cause invasive disease in infants in Mali. In addition, we show that MLST and flagellin gene sequencing, in association with traditional serum agglutination, are invaluable tools to help identify rare Salmonella serovars.

Water, sanitation, and hygiene information was collected during a matched case-control study of moderate and severe diarrhea (MSD) among 4,096 children < 5 years of age in Bamako, Mali. Primary use of piped water (conditional odds ratio [cOR] = 0.45; 0.34–0.62), continuous water access (cOR = 0.30; 0.20–0.43), fetching water daily (cOR = 0.77; 0.63–0.96), and breastfeeding (cOR = 0.65; 0.49–0.88) significantly reduced the likelihood of MSD. Fetching water in > 30 minutes (cOR = 2.56; 1.55–4.23) was associated with MSD. Piped tap water and courier-delivered water contained high (> 2 mg/L) concentrations of free residual chlorine and no detectable Escherichia coli. However, many households stored water overnight, resulting in inadequate free residual chlorine (< 0.2 mg/L) for preventing microbial contamination. Coliforms and E. coli were detected in 48% and 8% of stored household water samples, respectively. Although most of Bamako's population enjoys access to an improved water source, water quality is often compromised during household storage.

Maternal practices regarding children's health care have been recognized as an important factor associated with mortality rates among children < 5 years of age. We focused on health care-seeking practices of primary caretakers of children < 5 years of age with diarrheal disease in Kolkata. We interviewed caretakers of 1,058 children in a baseline survey and 6,077 children on six subsequent surveys. The prevalence of diarrhea during the preceding 2 weeks was 7.9% in the baseline survey and 5.7% (lowest 3.5% to highest 7.8%) in subsequent surveys. Multivariate logistic regression showed that formal education of primary caretakers was associated with seeking care outside the home (odds ratio [OR] = 15.5; 95% confidence interval [CI] [2.5–85.7]; P = 0.002). Multinomial logistic regression showed that formal education of the primary caretaker (OR = 21.4; 95% CI [3.2–139.0]; P = 0.002) and presence of dry mouth during diarrhea (OR = 17.3; 95% CI [2.7–110.9]; P = 0.003) were associated with seeking care from licensed providers compared with the children for whom care was not sought outside of the home. This health care utilization and attitudes survey (HUAS) can serve as a tool to identify the factors that influence a better health care-seeking pattern in urban slums of Kolkata.

Diarrhea is a leading cause of child mortality worldwide. Early recognition of symptoms and referral to medical treatment are essential. In 2007, we conducted a Healthcare Utilization and Attitudes Survey (HUAS) of 1,000 children randomly selected from a population census to define care-seeking patterns for diarrheal disease in Bamako, Mali, in preparation for the Global Enteric Multicenter Study (GEMS). We found that 57% of caretakers sought care for their child's diarrheal illness from traditional healers, and 27% of caretakers sought care from the government health center (GHC). Weighted logistic regression showed that seeking care from a traditional healer was associated with more severe reported diarrheal disease, like decreased urination (odds ratio [OR] = 3.35, 95% confidence interval [95% CI] = 1.19–9.41) and mucus or pus in stool (OR = 4.42, 95% CI = 1.35–14.51), along with other indicators of perceived susceptibility. A locally designed traditional healer referral system was, therefore, created that emphasized more severe disease. This system may serve as a model for health systems in West Africa.

In the predominantly rural Manhiça district, in southern Mozambique, diarrhea is one of the leading causes of death among children under 5 years. Caretakers randomly selected from the Demographic Surveillance Database were invited to participate in a community-based survey on use of healthcare services for gastroenteritis. Of those caretakers reporting an episode of diarrhea during the recall period, 65.2% in the first survey and 43.8% in the second survey reported seeking care at a health facility. Independent risk factors for seeking care in health facilities in the first survey included the presence of diarrhea with fever and not knowing any sign of dehydration; having a television at home was related with an independent decreased use of the health facilities. In the second survey, the use of health services was significantly associated with diarrhea with fever and vomiting. Establishment of continuous prospective monitoring allows accounting for changes in healthcare use that may occur because of seasonality or secular events.

We interviewed caretakers of 1,043 children < 5 years old in a baseline cross-sectional survey (April to May 2007) and > 20,000 children on five separate subsequent occasions (May of 2009 to December 31, 2010) to assess healthcare seeking patterns for diarrhea. Diarrhea prevalence during the preceding 2 weeks ranged from 26% at baseline to 4–11% during 2009–2010. Caretakers were less likely to seek healthcare outside the home for infants (versus older children) with diarrhea (adjusted odds ratio [aOR] = 0.33, confidence interval [CI] = 0.12–0.87). Caretakers of children with reduced food intake (aOR = 3.42, CI = 1.37–8.53) and sunken eyes during their diarrheal episode were more likely to seek care outside home (aOR = 4.76, CI = 1.13–8.89). Caretakers with formal education were more likely to provide oral rehydration solution (aOR = 3.01, CI = 1.41–6.42) and visit a healthcare facility (aOR = 3.32, CI = 1.56–7.07). Studies calculating diarrheal incidence and healthcare seeking should account for seasonal trends. Improving caretakers' knowledge of home management could prevent severe diarrhea.

We evaluated patterns of health care use for diarrhea among children 0–59 months of age residing in Mirzapur, Bangladesh, using a baseline survey conducted during May–June 2007 to inform the design of a planned diarrheal etiology case/control study. Caretakers of 7.4% of 1,128 children reported a diarrheal illness in the preceding 14 days; among 95 children with diarrhea, 24.2% had blood in the stool, 12.2% received oral rehydration solution, 27.6% received homemade fluids, and none received zinc at home. Caretakers of 87.9% sought care outside the home; 49.9% from a pharmacy, and 22.1% from a hospital or health center. The primary reasons for not seeking care were maternal perception that the illness was not serious enough (74.0%) and the high cost of treatment (21.9%). To improve management of childhood diarrhea in Mirzapur, Bangladesh, it will be important to address knowledge gaps in caretakers' assessment of illness severity, appropriate home management, and when to seek care in the formal sector. In addition, consideration should be given to inclusion of the diverse care-giving settings in clinical training activities for diarrheal disease management.

Measles has been a major killer among vaccine-preventable diseases in children < 5 years of age in develop- ing countries. Despite progress in global efforts to reduce mortality, measles remains a public health problem. Hospital- based measles surveillance was conducted in Manhica, Mozambique (July 2001-September 2004). Suspected cases and community-based controls were enrolled, and blood was collected for immunoglobulin M (IgM) confirmation. Two hun- dred fifty-three suspected cases and 477 controls were enrolled, with 85% (216 of 253) cases reported during a measles outbreak. Measles-IgM confirmation was 30% among suspected cases and 5% in controls. Fifty-eight percent (14 of 24) of laboratory-confirmed cases had records indicating previous measles vaccination. Mortality was 3% (8 of 246) among cases and 1% among controls (6 of 426). Forty-five percent (33 of 74) of cases were < 24 months of age and 22% occurred in infants < 9 months of age and were associated with a high case-fatality rate (25%). Our data suggest that improved diag- nostics, new tools to protect infants < 9 months of age, and a supplemental dose of measles vaccine could assist measles control.

In Bamako, Mali, where surveillance revealed a high incidence of Haemophilus influenzae type b (Hib) invasive disease, Hib conjugate vaccine was introduced into the Expanded Program on Immunization and the impact assessed. Annual confirmed Hib hospitalizations for infants 0-11 months of age fell from 175/10 5 to 44/10 5 ( P < 0.001); among infants 6-7 months of age Hib hospitalizations fell from 377/10 5 to 69/10 5 , (82% decrease, P < 0.001). Invasive Streptococcus pneumoniae hospitalizations remained unchanged. In a baseline serosurvey, only 3/200 infants 6-7 months of age (1.5%) had protective anti-polyribosylribitol phosphate (PRP) titers ≥ 0.15 μg/mL and 1(0.5%) had ≥ 1.0 μg/mL . In serosurveys 18 and 30 months after vaccine introduction, 168/201 (84%) and 184/200 (92%) infants, respectively, had titers ≥ 0.15 μg/mL and 141/201 (70%) and 163/200 (82%) had titers ≥ 1.0 μg/mL. Introduction of Hib vaccine led to rises in anti-PRP seroprevalence, significant reductions in Hib disease, and all-cause hospitalizations, whereas S. pneumoniae disease remained unchanged.

In Mozambique, as in many sub-Saharan countries, measles remains a public health problem. We conducted cross-sectional surveys in which we assessed measles-specific antibodies in serum and breast milk by plaque reduction neutralization (PRN) assay and measles secretory IgA in breast milk by enzyme-linked immunosorbent assay. A total of 151 persons1 month to 23 years of age were surveyed; 81 (53.6%) of 151 had PRN titers equal to or above the protective level (/= 200 mIU/mL). We found many serosusceptible persons, including 20.5% in whom no PRN antibody was detected. Almost all (96%) infants 6-8 months of age had non-protective PRN titers. Overall, 20.7% (6 of 29) of persons known to have received measles vaccine had non-protective titers. The geometric mean titer (GMT) of breast milk PRN antibodies was 41.6 mIU/mL (95% confidence interval [CI] = 34.0-51.0 mIU/mL) and the secretory IgA GMT was 227.6 (EU/mL) (95% CI = 179.1-289.1 EU/mL). The PRN titers of breast milk tended to increase with age. A notable proportion of the population in Manhiça, Mozambique apparently remains susceptible to clinical measles despite recent mass vaccination campaigns.

As infants lose maternally derived antibody, they experience a period when antibody levels are insufficient to protect against measles yet may interfere with immunization. In Kangaba Mali, sera were collected from 89 2-8-month-old infants and 32 9-10-month-old infants without a history of measles or vaccination; post-vaccination sera were collected from 24 of the 9-10-month-old infants 3-5 weeks after receiving measles vaccine. Measles antibody was measured by plaque reduction neutralization (PRN) and enzyme linked immunosorbent assay. At two months of age, 30% had protective PRN titers; among six-month-old infants, none had protective titers. Prior to vaccination, 16% of 9-10-month-old infants exhibited protective titers; all demonstrated protective titers post-vaccination. The early onset of the window of vulnerability in Kangaba infants likely reflects the changing ecology of measles in Africa. Ways to protect these vulnerable infants against measles must be devised.