Cholera outbreak caused by drinking unprotected well water contaminated with faeces from an open storm water drainage: Kampala City, Uganda, January 2019.

BACKGROUND: Kampala city slums, with one million dwellers living in poor sanitary conditions, frequently experience cholera outbreaks. On 6 January 2019, Rubaga Division notified the Uganda Ministry of Health of a suspected cholera outbreak in Sembule village. We investigated to identify the source and mode of transmission, and recommended evidence-based interventions. METHODS: We defined a suspected case as onset of profuse, painless, acute watery diarrhoea in a Kampala City resident (≥ 2 years) from 28 December 2018 to 11 February 2019. A confirmed case was a suspected case with Vibrio cholerae identified from the patient's stool specimen by culture. We found cases by record review and active community case-finding. We conducted a case-control study in Sembule village, the epi-center of this outbreak, to compare exposures between confirmed case-persons and asymptomatic controls, individually matched by age group. We overlaid rainfall data with the epidemic curve to identify temporal patterns between rain and illnesses. We conducted an environmental assessment, interviewed village local council members, and tested water samples from randomly-selected households and water sources using culture and PCR to identify V. cholerae. RESULTS: We identified 50 suspected case-patients, with three deaths (case-fatality rate: 6.0%). Of 45 case-patients with stool samples tested, 22 were confirmed positive for V. cholerae O1, serotype Ogawa. All age groups were affected; persons aged 5-14 years had the highest attack rate (AR) (8.2/100,000). The epidemic curve showed several point-source outbreaks; cases repeatedly spiked immediately following rainfall. Sembule village had a token-operated water tap, which had broken down 1 month before the outbreak, forcing residents to obtain water from one of three wells (Wells A, B, C) or a public tap. Environmental assessment showed that residents emptied their feces into a drainage channel connected to Well C. Drinking water from Well C was associated with illness (ORM-H = 21, 95% CI 4.6-93). Drinking water from a public tap (ORM-H = 0.07, 95% CI 0.014-0.304) was protective. Water from a container in one of eight households sampled tested positive for V. cholerae; water from Well C had coliform counts ˃ 900/100 ml. CONCLUSIONS: Drinking contaminated water from an unprotected well was associated with this cholera outbreak. We recommended emergency chlorination of drinking water, fixing the broken token tap, and closure of Well C.

Acute Metam Sodium Poisoning Caused by Occupational Exposure at a Flower Farm - Uganda, October 2016.

On October 25, 2016, media reports alerted the Uganda Ministry of Health to an outbreak of >80 cases of vomiting, syncope, and acute diarrhea among workers at a flower farm in central Uganda; 27 workers were hospitalized. On November 1, an investigation was undertaken by the Uganda Public Health Fellowship Program.* A case-control study found that working inside greenhouse 7, which had been fumigated with the organosulfur compound metam sodium the night of October 13, was strongly associated with illness. Employees who worked in this greenhouse during October 14-21 reported a strong "suffocating" smell in the greenhouse. Investigation revealed that, in violation of safety protocols, workers did not properly cover the soil after fumigation, allowing vapors to become trapped inside the greenhouse. The farm management, unaware of the lapse, failed to inform workers to avoid the vicinity of the fumigation. Respiratory protective measures were not routinely available for workers, which likely contributed to the severity and extent of the outbreak. Although metam sodium is generally considered to be of low risk when used according to manufacturer's instructions (1), occupational exposure in the absence of recommended safety measures can have serious health consequences. The investigation highlighted the importance of identifying potential occupational hazards to workers, as well as establishing safety protocols in occupational settings, training workers at risk, such as pesticide sprayers and flower pickers,† and ensuring enforcement of safety protocols. After this outbreak, the farm management reviewed, revised, and trained the workers on safety protocols to prevent future outbreaks.

Investigating a cholera outbreak in Kaiso Fishing Village, Hoima District, Uganda, October 2015.

Globally, even though improvements have been made to effective surveillance and response, communicable diseases such as cholera remain high priorities for national health programs, especially in Africa. High-quality surveillance information coupled with adequate laboratory facilities are effective in curbing outbreaks from such diseases, ultimately reducing morbidity and mortality. One way of building this capacity is through simulation of response to such health events. This case study based on a cholera outbreak investigated by FETP trainees in October 2015 in Uganda can be used to reinforce skills of frontline FETP trainees and other novice public health practitioners through a practical simulation approach. This activity should be completed in 2.5 hours.

Risk Factors for Podoconiosis: Kamwenge District, Western Uganda, September 2015.

AbstractPodoconiosis, a noninfectious elephantiasis, is a disabling neglected tropical disease. In August 2015, an elephantiasis case-cluster was reported in Kamwenge District, western Uganda. We investigated to identify the disease's nature and risk factors. We defined a suspected podoconiosis case as onset in a Kamwenge resident of bilateral asymmetrical lower limb swelling lasting ≥ 1 month, plus ≥ 1 of the following associated symptoms: skin itching, burning sensation, plantar edema, lymph ooze, prominent skin markings, rigid toes, or mossy papillomata. A probable case was a suspected case with negative microfilaria antigen immunochromatographic card test (ruling out filarial elephantiasis). We conducted active case-finding. In a case-control investigation, we tested the hypothesis that the disease was caused by prolonged foot skin exposure to irritant soils, using 40 probable case-persons and 80 asymptomatic village control-persons, individually matched by age and sex. We collected soil samples to characterize irritants. We identified 52 suspected (including 40 probable) cases with onset from 1980 to 2015. Prevalence rates increased with age; annual incidence (by reported onset of disease) was stable over time at 2.9/100,000. We found that 93% (37/40) of cases and 68% (54/80) of controls never wore shoes at work (Mantel-Haenszel odds ratio [ORMH] = 7.7; 95% [confidence interval] CI = 2.0-30); 80% (32/40) of cases and 49% (39/80) of controls never wore shoes at home (ORMH = 5.2; 95% CI = 1.8-15); and 70% (27/39) of cases and 44% (35/79) of controls washed feet at day end (versus immediately after work) (OR = 11; 95% CI = 2.1-56). Soil samples were characterized as rich black-red volcanic clays. In conclusion, this reported elephantiasis is podoconiosis associated with prolonged foot exposure to volcanic soil. We recommended foot hygiene and universal use of protective shoes.

Outbreak of pulmonary tuberculosis in a Chinese high school, 2009-2010.

BACKGROUND: In February 2009, a high school student was diagnosed with sputum-smear positive pulmonary tuberculosis (TB). One year later, 2 other students in the same grade developed sputum-smear positive TB. METHODS: We used tuberculin skin testing (TST), chest radiography, sputum smear, and symptomatology for case identification. We defined latent TB infection (LTBI) as a TST induration of 15 mm or larger, probable TB as a chest radiograph indicative of TB plus productive cough/hemoptysis for at least 2 weeks or TST induration of 15 mm or larger, and confirmed TB as 2 or more positive sputum smears or 1 positive sputum smear plus a chest radiograph indicative of TB. RESULTS: Of students in the same grade as the primary case-student, 26% (122/476) had LTBI and 4.8% (23/476) had probable/confirmed TB. Of teachers, 43% (18/42) had LTBI and none had probable/confirmed TB. Sharing a classroom with the primary case-student increased risk for LTBI (rate ratio = 2.5; 95% CI: 1.9-3.4) and probable/confirmed TB (rate ratio = 17, 95% CI: 7.8-39). Of students with LTBI in February 2009 who refused prophylaxis, 50% (11/22) had probable/confirmed TB in April 2010. CONCLUSIONS: This TB outbreak was likely started by delayed diagnosis of TB in the case-student and was facilitated by lack of post-exposure chemoprophylaxis. Post-exposure prophylaxis is strongly recommended for all TST-positive students.

Effect of aluminum hydroxide adjuvant on the immunogenicity of the 2009 pandemic influenza A/H1N1 vaccine: multi-level modeling of data with repeated measures.

OBJECTIVE: To evaluate the effect of the aluminum hydroxide (Al-OH) adjuvant on the 2009 pandemic influenza A/H1N1 (pH1N1) vaccine. METHODS: In a multicenter, double-blind, randomized, placebo-controlled trial, participants received two doses of split-virion formulation containing 15 µg hemagglutinin antigen, with or without aluminum hydroxide (Al-OH). We classified the participants into six age categories (>61 years, 41-60 years, 19-40 years, 13-18 years, 8-12 years, and 3-7 years) and obtained four blood samples from each participant on days 0, 21, 35, and 42 following the first dose of immunization. We assessed vaccine immunogenicity by measuring the geometric mean titer (GMT) of hemagglutination inhibiting antibody. We used a two-level model to evaluate the fixed effect of aluminum Al-OH and other factors, accounting for repeated measures. RESULTS: The predictions of repeated measurement on GMTs of formulations with or without Al-OH, were 80.35 and 112.72, respectively. Al-OH significantly reduced immunogenicity after controlling for time post immunization, age-group and gender. CONCLUSION: The Al-OH adjuvant does not increase but actually reduces the immunogenicity of the split-virion pH1N1 vaccine.

Association of maternal smoking status with breastfeeding practices: Missouri, 2005.

OBJECTIVE: We sought to determine the association of smoking status as a risk factor for reduced initiation and duration of breastfeeding. METHODS: The Missouri Pregnancy Related Assessment and Monitoring System collected a stratified sample of new mothers in 2005. Surveys were mailed, with telephone follow-up, and completed within 2 to 12 months after delivery. Respondents were classified as nonsmokers, smokers who quit during pregnancy, light smokers (10 cigarettes per day). Multivariable binomial regression and Cox proportional hazards models were used to assess breastfeeding initiation and duration according to smoking status. RESULTS: Overall, 1789 women participated (weighted response rate: 61%). Approximately 74% of the women ever breastfed; 31% of the women ever smoked while pregnant. Compared with nonsmokers, the moderate/heavy smokers and light smokers were less likely to initiate breastfeeding, after controlling for sociodemographic characteristics, the presence of other smokers in the household, alcohol use, mode of delivery, and infant hospitalization. Compared with nonsmokers, the moderate/heavy smokers, light smokers, and smokers who quit during pregnancy were more likely to wean over time, controlling for the same covariates. There were no significant differences between nonsmokers and smokers regarding reasons for not initiating or ceasing breastfeeding. CONCLUSIONS: Mothers who smoked initiated breastfeeding less often and weaned earlier than nonsmoking mothers. Incorporating knowledge of the association between smoking and breastfeeding into existing smoking-cessation and breastfeeding programs could provide opportunities to reduce perinatal exposure to tobacco smoke, improve interest in breastfeeding, and address other barriers to breastfeeding that smoking mothers may face.

A comparison of the health status and behavioral risk factors among English-speaking Hispanics and non-Hispanic Blacks and Whites in Missouri.

OBJECTIVES: The study objectives were to estimate the prevalence of chronic diseases and other health indicators for Hispanics in Missouri, and to compare their prevalence estimates with other racial/ethnic groups. DESIGN / SETTING / PARTICIPANTS: This study, conducted in public health and academic settings, used combined data from the 2002 and 2003 Missouri Behavioral Risk Factor Surveillance System and the 2003 Missouri County-Level Study. Data were post-stratified with Hispanic ethnicity as a separate group. MAIN OUTCOME MEASURES: Twenty health indicators were compared. Logistic regression was used to control for sociodemographic characteristics. RESULTS: Overall, 21.7% (95% confidence interval [CI] 13.4-30.0) of Hispanics, 19.8% (95% CI 14.4-25.2%) of non-Hispanic Blacks, and 12.2% (95% CI 11.2-13.1%) of non-Hispanic Whites had no insurance coverage. Hispanics were significantly less likely to report poor or fair health (12.1%, 95% CI 7.5-16.7%) than non-Hispanic Blacks (21.6%, 95% CI 17.2-26.0%), and less likely to report activity limitation (12.9%, 95% CI 8.0-17.9%) than non-Hispanic Whites (20.2%, 95% CI 19.1-21.2%). Controlling for sociodemographic characteristics, Hispanics had greater physician-diagnosed diabetes (OR = 2.0, 95% CI 1.0-3.3%) and Hispanics aged > or = 50 were less likely to have no sigmoidoscopy or colonoscopy in the past five years (OR = 0.5, 95% CI 0.2-1.0%) compared to non-Hispanic Whites. CONCLUSIONS: Other than lower healthcare coverage and diabetes status, the health indicators for English-speaking Hispanics were similar to, or better than, non-Hispanic Blacks and Whites. However, these data may not represent all Hispanics in Missouri since health status between English-speaking and non-English speaking Hispanics may differ significantly.

The health and economic burden of smoking in Missouri, 2000-2004.

This study used the Smoking-Attributable Mortality, Morbidity and Economic Cost (SAMMEC) software developed by the Centers for Disease Control and Prevention to assess the health consequences and economic burden due to smoking in Missouri. During 2000-2004, cigarette smoking resulted in 9,600 deaths (17.5% of all deaths), 132,103 Years of Potential Life Lost, and $2.4 billion in productivity loss annually in Missouri. These data show that Missouri suffers enormous human and financial losses from smoking.

Active and passive smoking among asthmatic Missourians: implications for health education.

OBJECTIVES: To estimate the prevalence of smoking and exposure to secondhand smoke among asthmatic Missourians and to describe associated predisposing factors. METHOD: The Missouri County-level Behavioral Risk Factor Survey, conducted among 15,059 non-institutionalized Missourians aged 18 years or older using random-digit-dialed telephone interviews during 2002-2003, was used in this study. RESULTS: Current smoking (28.4%) and regular exposure to secondhand smoke (19.9%-36.4%, depending on the setting) were prevalent among asthmatic Missourians. Among asthmatics, those with college or technical school education were less likely to be current smokers compared to those with less than a high school education [odds ratio (OR)=0.25, 95% confidence interval (CI): 0.11, 0.57]; African Americans were less likely to be current smokers than white (OR=0.24, 95% CI: 0.07, 0.83); however, among asthmatic non-current smokers, African Americans were more likely to expose to secondhand smoke one or more days per week inside home than whites. Of the asthmatic current smokers who had visited a physician in the past 12 months, 30.0% were not advised by health care professionals to quit smoking. CONCLUSIONS: Asthma intervention programs should strengthen smoking cessation components and should educate health care professionals about the importance of advising asthmatic patients to quit smoking.

Lung cancer mortality in relation to age, duration of smoking, and daily cigarette consumption: results from Cancer Prevention Study II.

The magnitude of the effect of smoking duration on lung cancer mortality relative to that of intensity (cigarettes/day) has practical implications for both tobacco control policy and research. This issue was addressed by R. Doll and R. Peto (J. Epidemiol. Commun. Health, 32: 303-313, 1978) in their historic analysis of one of the few large cohort studies in which intensity and duration were estimated separately. Their findings have been interpreted to mean that smoking duration is much more important than smoking intensity in causing lung cancer. The separate contributions of smoking duration and intensity to lung cancer risk have not been evaluated in other large prospective studies. We studied participants in the Cancer Prevention Study II, followed from 1982 through 1988. After restricting to people 40-79 years old who smoked < or =40 cigarettes per day at enrollment, we fit Poisson models for four age groups and evaluated lung cancer mortality (M) in relation to smoking duration (D) and intensity (I) on a double-log scale, as suggested by the Armitage-Doll multistage carcinogenesis model. The age-specific mortality estimates for men (M(m)) and for women (M(w)), when transformed to the original scale, were: ages 40-49: M(m) = e(-17.9) x D(1.9) x I(0.95), M(w) = e(-20.2) x D(2.8) x I(0.96); ages 50-59: M(m) = e(-17.4) x D(2.6) x I(0.52), M(m) = e(-17.2) x D(2.2) x I(0.75); ages 60-69: M(m) = e(-15.7) x D(2.4) x I(0.37), M(m) = e(-14.1) x D(1.5) x I(0.78); ages 70-79: M(m) = e(-13.0) x D(1.8) x I(0.39), M(m) = e(-13.2) x D(1.3) x I(0.95). Our study confirms that years of cigarette smoking is far more important than the number of cigarettes smoked per day in predicting lung cancer risk in United States men, regardless of age, and provides new evidence that a qualitatively similar pattern holds for women. The results support measures to prevent the uptake of smoking by adolescents and increase cessation. We discuss reasons why the associations we observe are lower than those reported by R. Doll and R. Peto (J. Epidemiol. Commun. Health, 32: 303-313, 1978).