Investments in blood safety improve the availability of blood to underserved areas in a sub-Saharan African country

BACKGROUND AND OBJECTIVES

Since 2004, several African countries, including Namibia, have received assistance from the U.S. President's Emergency Plan for AIDS Relief (PEPFAR). Gains have been documented in the safety and number of collected units in these countries, but the distribution of blood has not been described.

MATERIALS AND METHODS

Nine years of data on blood requests and issues from Namibia were stratified by region to describe temporal and spatial changes in the number and type of blood components issued to Namibian healthcare facilities nationally.

RESULTS

Between 2004 and 2007 (early years of PEPFAR support) and 2008-2011 (peak years of PEPFAR support), the average number of red cell units issued annually increased by 23.5% in seven densely populated but less-developed regions in northern Namibia; by 30% in two regions with urban centres; and by 35.1% in four sparsely populated rural regions.

CONCLUSION

Investments in blood safety and a policy decision to emphasize distribution of blood to underserved regions improved blood availability in remote rural areas and increased the proportion of units distributed as components. However, disparities persist in the distribution of blood between Namibia's urban and rural regions.

West Nile virus serosurvey and assessment of personal prevention efforts in an area with intense epizootic activity: Connecticut, 2000

West Nile virus (WNV) can cause large outbreaks of febrile illness and severe neurologic disease. This study estimates the seroprevalence of WNV infection and assesses risk perception and practices regarding potential exposures to mosquitoes of persons in an area with intense epizootics in 1999 and 2000. A serosurvey of persons aged > or = 12 years was conducted in southwestern Connecticut during October 10-15, 2000, using household-based stratified cluster sampling. Participants completed a questionnaire regarding concern for and personal measures taken with respect to WNV and provided a blood sample for WNV testing. Seven hundred thirty persons from 645 households participated. No person tested positive for WNV (95% CI: 0-0.5%). Overall, 44% of persons used mosquito repellent, 56% practiced > or = two personal precautions to avoid mosquitoes, and 61% of households did > or = two mosquito-source reduction activities. In multivariate analyses, using mosquito repellent was associated with age < 50 years, using English as the primary language in the home, being worried about WNV, being a little worried about pesticides, and finding mosquitoes frequently in the home (P<0.05). Females (OR = 2.0; CI = 1.2-2.9) and persons very worried about WNV (OR = 3.8; CI = 2.2-6.5) were more likely to practice > or = two personal precautions. Taking > or = two mosquito source reductions was associated with persons with English as the primary language (OR = 2.0; CI = 1.1-3.5) and finding a dead bird on the property (OR = 1.8; CI = 1.1-2.8). An intense epizootic can occur in an area without having a high risk for infection to humans. A better understanding of why certain people do not take personal protective measures, especially among those aged > or = 50 years and those whose primary language is not English, might be needed if educational campaigns are to prevent future WNV outbreaks.

West Nile encephalitis: an emerging disease in the United States

In 1999, an epidemic of West Nile virus (WNV) encephalitis occurred in New York City (NYC) and 2 surrounding New York counties. Simultaneously, an epizootic among American crows and other bird species occurred in 4 states. Indigenous transmission of WNV had never been documented in the western hemisphere until this epidemic. In 2000, the epizootic expanded to 12 states and the District of Columbia, and the epidemic continued in NYC, 5 New Jersey counties, and 1 Connecticut county. In addition to these outbreaks, several large epidemics of WNV have occurred in other regions of the world where this disease was absent or rare >5 years ago. Many of the WNV strains isolated during recent outbreaks demonstrate an extremely high degree of homology that strongly suggests widespread circulation of potentially epidemic strains of WNV. The high rates of severe neurologic illness and death among humans, horses, and birds in these outbreaks are unprecedented and unexplained. We review the current status of WNV in the United States.

Amplification of the DNA polymerase I gene of Treponema pallidum from whole blood of persons with syphilis

Previous reports suggest that Treponema pallidum bacteremia occurs in persons with syphilis exposure ('incubating syphilis') and in persons with primary or secondary syphilis. During a recent syphilis outbreak, whole blood samples from 32 persons with suspected syphilis or syphilis exposure were screened using polymerase chain reaction (PCR) to amplify the DNA polymerase I gene (polA) of T. pallidum. Of the 32 samples, polA was amplified from 13 (41%). Of these 13, three were determined to have incubating syphilis; two had primary or secondary syphilis and eight had latent syphilis. This study demonstrates that spirochetemia can occur throughout the course of T. pallidum infection.

Widespread West Nile virus activity, eastern United States, 2000

In 1999, the U.S. West Nile (WN) virus epidemic was preceded by widespread reports of avian deaths. In 2000, ArboNET, a cooperative WN virus surveillance system, was implemented to monitor the sentinel epizootic that precedes human infection. This report summarizes 2000 surveillance data, documents widespread virus activity in 2000, and demonstrates the utility of monitoring virus activity in animals to identify human risk for infection.

Two outbreaks of multidrug-resistant Salmonella serotype typhimurium DT104 infections linked to raw-milk cheese in Northern California

CONTEXT

Salmonella serotype Typhimurium definitive type 104 (DT104), with resistance to 5 drugs (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline), has emerged as the most common multidrug-resistant Salmonella strain in the United States. However, illnesses resulting from this strain have not been associated definitively with a source in this country.

OBJECTIVE

To determine the source of 2 outbreaks of Salmonella Typhimurium DT104.

DESIGN

Matched case-control study conducted between March 24 and April 5, 1997 (outbreak 1), enhanced surveillance for new cases dating from February 1, 1997 (outbreak 2), and environmental and laboratory investigations.

SETTING AND PARTICIPANTS

The case-control study included residents of 2 adjacent counties in northern California infected with the outbreak strain of Salmonella Typhimurium var Copenhagen and age-matched controls. For enhanced surveillance, a case was defined as Salmonella Typhimurium infection in a person exposed to fresh Mexican-style cheese.

MAIN OUTCOME MEASURES

Risk factors for infection and source of implicated food.

RESULTS

Outbreak 1 peaked in February 1997; 31 patients were confirmed by culture as having Salmonella Typhimurium var Copenhagen infection, isolates of which showed indistinguishable pulsed-field gel electrophoresis (PFGE) patterns. The outbreak strain was phage type DT104 with the 5-drug resistance pattern. Sixteen cases and 25 controls were enrolled in the case-control study; 15 of 16 Salmonella Typhimurium var Copenhagen cases compared with 14 of 24 matched controls reported eating unpasteurized Mexican-style cheese, (matched odds ratio, 7.9; 95% confidence interval, 1.1-354.9). Enhanced surveillance uncovered outbreak 2, which peaked in April 1997 and was caused by a non-Copenhagen variant of Salmonella Typhimurium. During outbreak 2, Salmonella Typhimurium was isolated from 79 persons who ate fresh Mexican-style cheese from street vendors and from cheese samples and raw milk. The PFGE pattern of the milk isolate matched 1 of the 3 patterns recovered from patients; all strains were phage type DT104b with the 5-drug resistance pattern.

CONCLUSION

Raw-milk products pose a risk for multidrug-resistant Salmonella Typhimurium DT104 infections.

First recorded outbreak of yellow fever in Kenya, 1992-1993. II. Entomologic investigations

The first recorded outbreak of yellow fever in Kenya occurred from mid-1992 through March 1993 in the south Kerio Valley, Rift Valley Province. We conducted entomologic studies in February-March 1993 to identify the likely vectors and determine the potential for transmission in the surrounding rural and urban areas. Mosquitoes were collected by landing capture and processed for virus isolation. Container surveys were conducted around human habitation. Transmission was mainly in woodland of varying density, at altitudes of 1,300-1,800 m. The abundance of Aedes africanus in this biotope, and two isolations of virus from pools of this species, suggest that it was the principal vector in the main period of the outbreak. A third isolate was made from a pool of Ae. keniensis, a little-known species that was collected in the same biotope. Other known yellow fever vectors that were collected in the arid parts of the valley may have been involved at an earlier stage of the epidemic. Vervet monkeys and baboons were present in the outbreak area. Peridomestic mosquito species were absent but abundant at urban sites outside the outbreak area. The entomologic and epidemiologic evidence indicate that this was a sylvatic outbreak in which human cases were directly linked to the epizootic and were independent of other human cases. The region of the Kerio Valley is probably subject to recurrent wandering epizootics of yellow fever, although previous episodes of scattered human infection have gone unrecorded. The risk that the disease could emerge as an urban problem in Kenya should not be ignored.

First recorded outbreak of yellow fever in Kenya, 1992-1993. I. Epidemiologic investigations

Outbreaks of yellow fever (YF) have never been recorded in Kenya. However, in September 1992, cases of hemorrhagic fever (HF) were reported in the Kerio Valley to the Kenya Ministry of Health. Early in 1993, the disease was confirmed as YF and a mass vaccination campaign was initiated. Cases of suspected YF were identified through medical record review and hospital-based disease surveillance by using a clinical case definition. Case-patients were confirmed serologically and virologically. We documented 55 persons with HF from three districts of the Rift Valley Province in the period of September 10, 1992 through March 11, 1993 (attack rate = 27.4/100,000 population). Twenty-six (47%) of the 55 persons had serologic evidence of recent YF infection, and three of these persons were also confirmed by YF virus isolation. No serum was available from the other 29 HF cases. In addition, YF virus was isolated from a person from the epidemic area who had a nonspecific febrile illness but did not meet the case definition. Five patients with confirmed cases of YF died, a case-fatality rate of 19%. Women with confirmed cases of YF were 10.9 times more likely to die than men (P = 0.010, by Fisher's exact test). Of the 26 patients with serologic or virologic evidence of YF, and for whom definite age was known, 21 (81%) were between 10 and 39 years of age, and 19 (73%) were males. All patients with confirmed YF infection lived in rural areas. There was only one instance of multiple cases within a single family, and this was associated with bush-clearing activity. This was the first documented outbreak of YF in Kenya, a classic example of a sylvatic transmission cycle. Surveillance in rural and urban areas outside the vaccination area should be intensified.

Capsule switching of Neisseria meningitidis

The different sialic acid (serogroups B, C, Y, and W-135) and nonsialic acid (serogroup A) capsular polysaccharides expressed by Neisseria meningitidis are major virulence factors and are used as epidemiologic markers and vaccine targets. However, the identification of meningococcal isolates with similar genetic markers but expressing different capsular polysaccharides suggests that meningococcal clones can switch the type of capsule they express. We identified, except for capsule, isogenic serogroups B [(alpha2-->8)-linked polysialic acid] and C [(alpha2-->9)-linked polysialic acid] meningococcal isolates from an outbreak of meningococcal disease in the U. S. Pacific Northwest. We used these isolates and prototype serogroup A, B, C, Y, and W-135 strains to define the capsular biosynthetic and transport operons of the major meningococcal serogroups and to show that switching from the B to C capsule in the outbreak strain was the result of allelic exchange of the polysialyltransferase. Capsule switching was probably the result of transformation and horizontal DNA exchange in vivo of a serogroup C capsule biosynthetic operon. These findings indicate that closely related virulent meningococcal clones may not be recognized by traditional serogroup-based surveillance and can escape vaccine-induced or natural protective immunity by capsule switching. Capsule switching may be an important virulence mechanism of meningococci and other encapsulated bacterial pathogens. As vaccine development progresses and broader immunization with capsular polysaccharide conjugate vaccines becomes a reality, the ability to switch capsular types may have important implications for the impact of these vaccines.

Risk factors for adverse outcome in persons with pneumococcal pneumonia

OBJECTIVE

To identify risk factors for death and respiratory failure in persons with penicillin-sensitive pneumococcal bacteremia and pneumonia from data available at initial clinical evaluation.

DESIGN

Retrospective chart review of persons with pneumococcal bacteremia and pneumonia.

SETTING

Tertiary care medical center (University of California Davis Medical Center, Sacramento).

PATIENTS

One hundred two consecutive adults admitted to the hospital for treatment of pneumococcal pneumonia with bacteremia.

RESULTS

Of 102 persons, 25 (25%; 95% confidence interval [CI], 17 to 34%) died and 17 (16%; 95% CI, 10 to 25%) survived mechanical ventilation for respiratory failure. In univariate analyses, persons with preexisting lung disease (relative risk [RR], 2.0; 95% CI, 1.3 to 3.1), initial body temperature < 38 degrees C (RR, 2.1; 95% CI, 1.3 to 3.6), or nosocomial infections (RR, 2.5; 95% CI, 1.8 to 3.6) or who were > or = 48 years old (RR, 2.7; 95% CI, 1.5 to 4.8) were at greater risk for adverse outcomes than persons without these risk factors. Of 25 persons without these risk factors, only one (4%; 95% CI, 0 to 20%) died, and the remaining 24 persons did not require intensive care. Using these risk factors in a multivariate logistic model, death or respiratory failure would have been predicted in 67% of persons and better outcome predicted in 83% of the persons. In multivariate analysis, nosocomial infection was the greatest risk factor (adjusted odds ratio, 17.3; 95% CI, 3.1 to 98).

CONCLUSIONS

Risk factors identified at hospital admission can predict the outcome in persons with pneumococcal pneumonia and bacteremia. Identifying these factors may allow earlier use of intensive care or more aggressive treatment. Independent of age, nosocomially acquired infections were the greatest risk factor for death or respiratory failure.

Infectious disease surveillance during emergency relief to Bhutanese refugees in Nepal

OBJECTIVE

To implement simplified infectious disease surveillance and epidemic disease control during the relocation of Bhutanese refugees to Nepal.

DESIGN

Longitudinal observation study of mortality and morbidity.

SETTING

Refugee health units in six refugee camps housing 73,500 Bhutanese refugees in the eastern tropical lowland between Nepal and India.

INTERVENTIONS

Infectious disease surveillance and community-based programs to promote vitamin A supplementation, measles vaccination, oral rehydration therapy, and early use of antibiotics to treat acute respiratory infection.

MAIN OUTCOME MEASURES

Crude mortality rate, mortality rate for children younger than 5 years, and cause-specific mortality.

RESULTS

Crude mortality rates up to 1.15 deaths per 10,000 persons per day were reported during the first 6 months of surveillance. The leading causes of death were measles, diarrhea, and acute respiratory infections. Surveillance data were used to institute changes in public health management including measles vaccination, vitamin A supplementation, and control programs for diarrhea and acute respiratory infections and to ensure rapid responses to cholera, Shigella dysentery, and meningoencephalitis. Within 4 months of establishing disease control interventions, crude mortality rates were reduced by 75% and were below emergency levels.

CONCLUSIONS

Simple, sustainable disease surveillance in refugee populations is essential during emergency relief efforts. Data can be used to direct community-based public health interventions to control common infectious diseases and reduce high mortality rates among refugees while placing a minimal burden on health workers.

Epidemiologic aspects of a St. Louis encephalitis epidemic in Jefferson County Arkansas, 1991

In 1991, the first epidemic of St. Louis encephalitis (SLE) ever reported in Arkansas resulted in 25 cases in Pine Bluff (attack rate: 44 per 100,000; 95% confidence interval [CI] 28-65). To identify risk factors for SLE viral infection and risk factors for neuroinvasive illness, we conducted a community-based, cross-sectional study of noninfected and asymptomatically infected persons and a case-control study of asymptomatically and symptomatically infected persons. The SLE viral infection rate was similar in all age groups and in all studied census tracts. Risk factors for asymptomatic infection included: living in a low income household (relative risk [RR] = 2.6, 95% CI 1.1-6.0), sitting outside in the evening (RR = 2.1, 95% CI 1.0-4.8), and living in homes with porches (RR = 2.9, 95% CI 0.9-9.3) or near open storm drains (RR = 2.2, 95% CI 1.0-4.9). Compared with asymptomatically infected persons, symptomatic persons were older (odds ratio [OR] for age > or = 55 years = 13.0, 95% CI 1.2-334) and more likely to have a previous history of hypertension (OR = 8.5, 95% CI 1.1-72). Our results indicate that advanced age is the most important risk factor for developing encephalitis after infection with SLE virus. Hypertension and vascular disease may predispose to neuroinvasive disease, but this epidemiologic study has not ruled out the confounding effects of age.

Entomologic investigations of an epidemic of St. Louis encephalitis in Pine Bluff, Arkansas, 1991

An epidemic of St. Louis encephalitis (SLE) occurred in Jefferson County, Arkansas during July-August 1991. At least 26 human cases were involved, with 25 cases in the town of Pine Bluff. Twelve isolates of SLE virus were obtained from mosquitoes collected in Pine Bluff between August 13 and 24: 11 from pools of Culex pipiens quinquefasciatus, resulting in a minimum infection rate of 1.6 per 1,000 (n = 6,768) for this subspecies, and one isolate from a pool of 22 mosquitoes identified as Cx. (Culex) spp. Three of the SLE-positive pools, two from Cx. p. quinquefasciatus and one from Cx. (Cux.) spp., also yielded isolates of Flanders virus. Larval surveys resulted in the collection of seven species in four genera from 28 larva-positive habitats and the identification of one significant site of Cx. p. quinquefasciatus production. Ecologic assessments conducted at 12 randomly selected residences resulted in the identification of 17 larva-positive habitats, for an average mosquito-positive habitat rate of 1.4 per residence, and a Cx. p. quinquefasciatus larva-positive habitat rate of 0.6 per residence. Aedes albopictus and Cx. p. quinquefasciatus were the species most frequently encountered in larval surveys in residential neighborhoods.

Mortality rates in displaced and resident populations of central Somalia during 1992 famine

Famine and civil war have resulted in high mortality rates and large population displacements in Somalia. To assess mortality rates and risk factors for mortality, we carried out surveys in the central Somali towns of Afgoi and Baidoa in November and December, 1992. In Baidoa we surveyed displaced persons living in camps; the average daily crude mortality rate was 16.8 (95% CI 14.6-19.1) per 10,000 population during the 232 days before the survey. An estimated 74% of children under 5 years living in displaced persons camps died during this period. In Afgoi, where both displaced and resident populations were surveyed, the crude mortality rate was 4.7 (3.9-5.5) deaths per 10,000 per day. Although mortality rates for all displaced persons were high, people living in temporary camps were at highest risk of death. As in other famine-related disasters, preventable infectious diseases such as measles and diarrhoea were the primary causes of death in both towns. These mortality rates are among the highest documented for a civilian population over a long period. Community-based public health interventions to prevent and control common infectious diseases are needed to reduce these exceptionally high mortality rates in Somalia.

Prevalence and risk factors for diabetes and diabetes-related amputations in American Indians in southern Arizona

OBJECTIVE

To describe the prevalence of NIDDM and LEA using data from a computer-based patient data base.

RESEARCH DESIGN AND METHODS

Diabetic patients with and without LEA, and nondiabetic patients were identified by computer search. Charts of diabetic patients were reviewed for confirmation of diagnosis of diabetes and diabetes-related amputation. The diabetic and nondiabetic populations were described, and certain risk factors were identified.

RESULTS

The overall prevalence of NIDDM in this tribe in 1985-1986 was 18.3/100 adults (> or = 18 yr of age), whereas the prevalence of LEA/100 adults with NIDDM was 10.3%. Females were 1.3 times as likely to have diagnosed diabetes as males (95% CI 1.2-1.4), and males with diabetes were 1.4 times more likely to have had LEA than females with diabetes (95% CI 1.1-1.9).

CONCLUSIONS

Automated health-care delivery data base used for this tribe can be used to maintain surveillance for diabetes and amputations in diabetic patients. Effective programs to prevent complications of diabetes, such as LEA, in this tribe are urgently needed.

St. Louis encephalitis in Arkansas

The first outbreak of St. Louis encephalitis (SLE) in Arkansas occurred in Pine Bluff (Jefferson County) during July-August 1991. Cases of SLE were identified mainly through reporting by physicians in Jefferson and surrounding counties. In addition, testing of stored cerebrospinal fluid specimens, a hospital chart review, and a serosurvey were performed in Pine Bluff. Twenty-eight Arkansas residents, five of whom died, had cases of SLE. Half the case patients were over age 60, and nearly half had hypertension. The serosurvey confirmed that infection with the SLE virus was not new to Pine Bluff, and that most infections in 1991 were asymptomatic. Arkansas physicians may see more cases of SLE in 1992. SLE epidemiology, clinical presentation, diagnosis, and preventive measures are reviewed.

Screening for lung cancer: effective tests awaiting effective treatment

In 1989 there were an estimated 155,000 new cases of lung cancer in the United States. While the majority of these cases occurred in smokers, at least 5-10% are felt to be attributable to occupational exposures. This chapter reviews various occupational screening programs for lung cancer and discusses their efficacy. New screening techniques and new treatments for lung cancer are described.

End state renal disease among Native Americans, 1983-86

We used data reported to Medicare from 1983 through 1986 to determine the incidence of end-stage renal disease (ESRD) among Native Americans and Whites in the United States. The 1,075 Native American cases represented an annual incidence, age-adjusted to the White population, of 269 per million, 2.8 times the rate for Whites. Fifty-six percent of Native American cases and 27 percent of the White cases were attributed to diabetes, indicating that ESRD is a major problem. Diabetes control provides the greatest opportunity for prevention.