Human immunodeficiency virus seropositivity and malaria as risk factors for third-trimester anemia in asymptomatic pregnant women in western Kenya.

To assess risk factors for anemia in late pregnancy, we studied healthy pregnant women with a singleton uncomplicated pregnancy of > or = 32 weeks attending the prenatal clinic in the Provincial Hospital in Kisumu, Kenya. Between June 1996 and December 1998, 4,608 pregnant women had a blood sample collected for hemoglobin (Hb) measurement, malaria smear, and testing for human immunodeficiency virus (HIV). The mean +/- standard deviation of Hb was 9.58 +/- 1.8 g/dL; 21% had malaria in their blood; and 25% of the women were HIV seropositive. Plasmodium falciparum parasitemia was more common among HIV-seropositive women in all gravidities compared with HIV-seronegative women (risk ratio, 1.71; 95% confidence interval, 1.53-1.92). In a multivariate analysis, for primi- and secundigravidae women, the factors malaria, belonging to the Luo tribe, and HIV seropositivity were significantly associated with any anemia (Hb < 11 g/dL), and HIV seropositivity and documented fever were associated with severe anemia (Hb < 7 g/dL). In women of higher gravidities, HIV seropositivity was the only statistically significant factor associated with any anemia or with severe anemia. Asymptomatic HIV seropositivity is an important risk factor to be considered in the differential diagnosis of maternal anemia, independent of P. falciparum parasitemia.

Tumor necrosis factor-alpha promoter variant 2 (TNF2) is associated with pre-term delivery, infant mortality, and malaria morbidity in western Kenya: Asembo Bay Cohort Project IX.

A polymorphism in the promoter region of the tumor necrosis factor-alpha (TNF-alpha) gene, with a guanine to adenine nucleotide change at position -308, TNF2 is associated with increased TNF-alpha production. TNF2 homozygotes have a higher risk of severe disease and/or death due to cerebral malaria and other infectious diseases. We investigated the impact of this allele on malaria morbidity and mortality in young children who participated in an immuno-epidemiologic cohort study of malaria in an area of intense perennial Plasmodium falciparum transmission in western Kenya. A total of 1,048 children were genotyped. Poisson regression and Cox proportional hazards models were used to determine the relationship between TNF-308 variants and morbidity and mortality. The gene frequencies of the TNF1 and TNF2 alleles were 0.90 and 0.10, respectively. TNF2 homozygosity was associated with pre-term birth when compared with TNF1 homozygotes [relative risk (RR) 7.3, 95% CI, 2.85-18.9, P = 0.002) and heterozygotes (RR 6.7, 95% CI 2.0-23.0, P = 0.008). Among children born prematurely, the TNF2 allele was significantly associated with a higher risk of death in infancy compared with TNF1 (RR 7.47, 95% CI 2.36-23.6). The risk of death was higher among TNF2 homozygotes than among heterozygotes. The TNF2 allele was significantly associated with high density P. falciparum parasitemia (RR 1.11, 95% CI 1.0-1.24). Among low birth weight children, the TNF2 allele was associated with severe anemia (RR 2.16, 95% CI 1.17-4.01) and showed a trend toward a risk for severe malaria anemia (RR 1.99, 95% CI 0.89-4.46). These data suggest that TNF2 is a risk factor for pre-term birth and early childhood mortality and malaria morbidity in children in this region. Further understanding of the pathogenic mechanisms underlying this association is required.

Efficacy of mefloquine and sulfadoxine-pyrimethamine for the treatment of uncomplicated Plasmodium falciparum infection in Machinga District, Malawi, 1998.

In response to the spread of chloroquine-resistant Plasmodium falciparum, Malawi changed its first-line antimalarial drug in 1993 from chloroquine to sulfadoxine-pyrimethamine (SP). Surveillance data has suggested that resistance to SP may be increasing. We compared the efficacy of SP with a potential successor, mefloquine (MQ). By use of a modified World Health Organization in vivo protocol, children infected with P. falciparum were randomized to receive SP (sulfadoxine 25 mg/kg) or MQ (15 mg/kg). We observed combined RII and RIII parasitologic failures of 20.0 and 22.0% in the SP and MQ arms, respectively. Among those in the MQ arm, the relative hazard of failing with a Day 2 drug level < 500 ng/mL was 10.6 times higher than those with levels > or = 500 ng/mL. Given the decreased efficacy of the first-line antimalarial drug and the high failure rates of MQ at this lower dosage, Malawi should consider assessing the efficacy and feasibility of alternative drugs to treat uncomplicated falciparum malaria.

Outbreak of Legionnaires' disease associated with a display whirlpool spa.

BACKGROUND: Recognized outbreaks of Legionnaires' disease (LD) are rare; when they occur, they provide opportunities to understand the epidemiology of the illness and improve prevention strategies. We investigated a population-based outbreak. METHODS: After the confirmation of LD in October 1996 in five people in neighbouring towns in southwest Virginia, active surveillance for additional cases was undertaken. A case-control study was conducted to identify exposures associated with illness, followed by a cohort study among employees of the facility at which the source of the outbreak was located in order to assess unrecognized exposure and illness. Samples of likely sources of LD in the facility were cultured for LEGIONELLA: RESULTS: In all, 23 laboratory-confirmed cases of LD were eventually identified. Of the 15 cases in the case-control study, 14 (93%) reported visiting a home-improvement store, compared with 12 (27%) of 45 controls (matched odds ratio [MOR] = 23.3; 95% CI : 3-182). Among home-improvement centre patrons, 10 (77%) of 13 cases questioned recalled either visiting or walking by a display whirlpool spa, compared with 3 (25%) of 12 controls (MOR = 5.5; 95% CI : 0.7-256.0). Two cases' sputum isolates were an exact match, by monoclonal antibody subtyping and arbitrarily primed polymerase chain reaction, to a whirlpool spa filter isolate from the store. Employees reporting more exposure to the display spas were more likely to report symptoms of LD or to have an elevated titre. CONCLUSIONS: This investigation shows that LD can be transmitted from a whirlpool spa used for display only, and highlights the need for minimizing the risk of transmission of LD from all water-filled spas. Key messages This paper describes an investigation of a population-based outbreak of Legionnaires' disease (LD). A case-control study first identified a home-improvement store as the likely source of the outbreak. An environmental investigation later confirmed that finding, as two cases' sputum isolates were an exact match, by monoclonal antibody subtyping and arbitrarily primed polymerase chain reaction, to a whirlpool spa filter isolate from the store. The spa was intended and used for display only.

Risk factors for HIV infection among asymptomatic pregnant women attending an antenatal clinic in western Kenya.

Our objective was to evaluate HIV prevalence and identify risk factors for HIV infection among women attending the antenatal clinic (ANC) at a large public hospital in Kisumu town, western Kenya. Between June 1996 and November 1997, in the context of a study to determine the effect of placental malaria on mother-to-child transmission of HIV in western Kenya, HIV-1 antibody testing was offered to women with a singleton uncomplicated pregnancy of > or =32 weeks' gestation attending the ANC. Women were interviewed using a structured questionnaire and had a fingerstick blood sample collected for haemoglobin (Hb), malaria smears, and HIV antibody testing. Overall HIV seroprevalence was 26.1% (743/2844) (95% confidence interval (CI): 24.5-27.7) and in bivariate evaluation was significantly associated with anaemia (Hb <11 g/dl) (risk ratio (RR) 1.8), malarial parasitaemia (RR 1.6), fever (axillary temperature > or =37.5 degrees C at screening) (RR 1.6), a history of being treated for either vaginal discharge (RR 1.5) or tuberculosis (RR 1.6), reported alcohol consumption (RR 1.6), being an unmarried multigravida (RR 2.2) or a history of the most recent child having died (RR 2.0). Poisson regression analysis for all women identified 5 significant factors independently associated with HIV seropositivity: anaemia (adjusted RR 1.7; 95% CI 1.3-2.0), malarial parasitaemia (adjusted RR 1.7; 95% CI 1.4-2.0), a history of being treated for vaginal discharge (adjusted RR 1.5; 95% CI 1.1-2.0), fever (adjusted RR 2.0; 95% CI 1.3-3.2) and reported alcohol consumption (adjusted RR 1.6; 95% CI 1.1-2.5). Multigravidae women whose most recent child had died were also more likely to be HIV seropositive (adjusted RR 1.9; 95% CI 1.7-2.8). Only 5.5% (156/2844) of the women had none of these risk factors, of whom 12% (18/156) were HIV(+). Even though the model containing the 5 identified factors fitted the data well (goodness-of-fit chi2=18.41, P=0.10), its collective capacity to predict HIV infection was poor; while 74% of the truly positive women were correctly predicted positive by the model, 52% of the truly negative women were misclassified. Among pregnant women attending the ANC in western Kenya, we were unable to identify a subgroup at risk of HIV infection using non-serological information, indicating that wherever possible universal access to voluntary HIV counselling and testing would be preferable to targeted screening.

PIP: This study evaluated the HIV prevalence and identified the risk factors for HIV infection among women attending the antenatal clinic at a public hospital in Kisumu, western Kenya. Also, the effect of placental malaria on vertical HIV transmission were determined using structured interviews and HIV-1 antibody testing and hemoglobin malaria smears were offered to the respondents. Overall, HIV seroprevalence was 26.1% (743/2844) (95% confidence interval [CI]: 24.5-27.7) and in bivariate evaluation was significantly associated with anemia (risk ratio [RR] 1.8), malarial parasitemia (RR 1.6), fever (RR 1.6), a history of being treated for either vaginal discharge (RR 1.5) or tuberculosis (RR 1.6), alcohol consumption (RR 1.6), being an unmarried multigravida (RR 2.2), or a history of the most recent child having died (RR 2.0). Using the Poisson regression analysis, 5 significant factors associated with HIV seropositivity were identified: anemia, malarial parasitemia, and history of being treated for vaginal discharge, fever, and reported alcohol consumption. Among the pregnant women, the researchers were unable to identify a subgroup at risk of HIV infection using nonserological information, indicating that universal access to voluntary HIV counseling and testing would be preferable to targeted screening.

Cigarette smoking and invasive pneumococcal disease. Active Bacterial Core Surveillance Team.

BACKGROUND: Approximately half of otherwise healthy adults with invasive pneumococcal disease are cigarette smokers. We conducted a population-based case-control study to assess the importance of cigarette smoking and other factors as risk factors for pneumococcal infections. METHODS: We identified immunocompetent patients who were 18 to 64 years old and who had invasive pneumococcal disease (as defined by the isolation of Streptococcus pneumoniae from a normally sterile site) by active surveillance of laboratories in metropolitan Atlanta, Baltimore, and Toronto. Telephone interviews were conducted with 228 patients and 301 control subjects who were reached by random-digit dialing. RESULTS: Fifty-eight percent of the patients and 24 percent of the control subjects were current smokers. Invasive pneumococcal disease was associated with cigarette smoking (odds ratio, 4.1; 95 percent confidence interval, 2.4 to 7.3) and with passive smoking among nonsmokers (odds ratio, 2.5; 95 percent confidence interval, 1.2 to 5.1) after adjustment by logistic-regression analysis for age, study site, and independent risk factors such as male sex, black race, chronic illness, low level of education, and living with young children who were in day care. There were dose-response relations for the current number of cigarettes smoked per day, pack-years of smoking, and time since quitting. The adjusted population attributable risk was 51 percent for cigarette smoking, 17 percent for passive smoking, and 14 percent for chronic illness. CONCLUSIONS: Cigarette smoking is the strongest independent risk factor for invasive pneumococcal disease among immunocompetent, nonelderly adults. Because of the high prevalence of smoking and the large population attributable risk, programs to reduce both smoking and exposure to environmental tobacco smoke have the potential to reduce the incidence of pneumococcal disease.

Clinical outcomes of meningitis caused by Streptococcus pneumoniae in the era of antibiotic resistance.

Limited data are available on clinical outcomes of meningitis due to cefotaxime-nonsusceptible Streptococcus pneumoniae. We analyzed data from 109 cases of pneumococcal meningitis in Atlanta, Baltimore, and San Antonio, which were identified through population-based active surveillance from November 1994 to April 1996. Pneumococcal isolates from 9% of the cases were resistant to cefotaxime, and isolates from 11% had intermediate susceptibility. Children were more likely to have cephalosporin-nonsusceptible pneumococcal meningitis, but mortality was significantly higher among adults aged 18-64 years. Vancomycin was given upon admission to 29% of patients, and within 48 h of admission to 52%. Nonsusceptibility to cefotaxime was not associated with the following outcomes: increased mortality, prolonged length of hospital or intensive care unit (ICU) stay, requirement of intubation or oxygen, ICU care, discharge to another medical or long-term-care facility, or neurological deficit. Empirical use of vancomycin, current prevalence of drug-resistant S. pneumoniae, and degree of nonsusceptibility to cefotaxime may have influenced these findings.

Invasive pneumococcal infection in Baltimore, Md: implications for immunization policy.

BACKGROUND: Streptococcus pneumoniae is a leading cause of infectious morbidity and mortality. Although blacks are known to have a higher incidence of invasive pneumococcal infection than whites, detailed analyses of these differences and their implications for vaccine prevention have not been reported. OBJECTIVE: To describe the epidemiological characteristics of invasive pneumococcal infection in Baltimore, Md, and its implications for immunization policy. METHODS: Analysis of active, laboratory-based surveillance during 1995 and 1996 among residents of the Baltimore metropolitan area. RESULTS: Of 1412 cases, 615 patients (43.6%) were classified as white and 766 (54.2%) as black. The annual incidence of invasive pneumococcal infection among white and black residents of the Baltimore metropolitan area was 17.8 and 59.2 per 100000 population, respectively (P<.01). Among patients aged 18 years and older, the median age of blacks with invasive pneumococcal infections was 27 years younger than that of whites (P<.01). Among males 40 to 49 years old, blacks had a 12-fold higher average incidence than whites (average incidence, 114.5 and 9.3, respectively; P<.01). By the age of 65 years, 83.8% of cases had occurred in black adults, as compared with 43.8% in white adults (P<.01). In a regression model, age, black race, male sex, low median family income, and county prevalence of acquired immunodeficiency syndrome were each independently associated with a higher incidence of pneumococcal infection. CONCLUSIONS: Young urban black adults in the Baltimore metropolitan area have a dramatically higher incidence of invasive pneumococcal infection than whites. The vast majority of cases of invasive pneumococcal infection in blacks occur before age 65 years. Current immunization efforts have not addressed the high incidence of pneumococcal infection in this population.

Incidence of community-acquired pneumonia requiring hospitalization. Results of a population-based active surveillance Study in Ohio. The Community-Based Pneumonia Incidence Study Group.

BACKGROUND: Pneumonia is the leading cause of death due to infectious diseases in the United States; however, the incidence of most infections causing community-acquired pneumonia in adults is not well defined. METHODS: We evaluated all adults, residing in 2 counties in Ohio, who were hospitalized in 1991 because of community-acquired pneumonia. Information about risk factors, symptoms, and outcome was collected through interview and medical chart review. Serum samples were collected from consenting individuals during the acute and convalescent phases, and specific etiologic diagnoses were assigned based on results of bacteriologic and immunologic tests. RESULTS: The incidence of community-acquired pneumonia requiring hospitalization in the study counties in 1991 was 266.8 per 100,000 population; the overall case-fatality rate was 8.8%. Pneumonia incidence was higher among blacks than whites (337.7/100,000 vs 253.9/ 100,000; P < .001), was higher among males than females (291.4 vs 244.8; P < .001), and increased with age (91.6/100,000 for persons aged < 45 years, 277.2/ 100,000 for persons aged 45-64 years, and 1012.3/ 100,000 for persons aged > or = 65 years; P < .001). Extrapolation from study incidence data showed the projected annual number of cases of community-acquired pneumonia requiring hospitalization in the United States to be 485,000. These data provide previously unavailable estimates of the annual number of cases that are due to Legionella species (8000-18,000), Mycoplasma pneumoniae (18,700-108,000), and Chlamydia pneumoniae (5890-49,700). CONCLUSIONS: These data provide information about the importance of community-acquired pneumonia and the relative and overall impact of specific causes of pneumonia. The study provides a basis for choosing optimal empiric pneumonia therapy, and allows interventions for prevention of pneumonia to be targeted at groups at greatest risk for serious illness and death.