Trends in malaria prevalence and health related socioeconomic inequality in rural western Kenya: results from repeated household malaria cross-sectional surveys from 2006 to 2013.

OBJECTIVE: The objective of this analysis was to examine trends in malaria parasite prevalence and related socioeconomic inequalities in malaria indicators from 2006 to 2013 during a period of intensification of malaria control interventions in Siaya County, western Kenya. METHODS: Data were analysed from eight independent annual cross-sectional surveys from a combined sample of 19 315 individuals selected from 7253 households. Study setting was a health and demographic surveillance area of western Kenya. Data collected included demographic factors, household assets, fever and medication use, malaria parasitaemia by microscopy, insecticide-treated bed net (ITN) use and care-seeking behaviour. Households were classified into five socioeconomic status and dichotomised into poorest households (poorest 60%) and less poor households (richest 40%). Adjusted prevalence ratios (aPR) were calculated using a multivariate generalised linear model accounting for clustering and cox proportional hazard for pooled data assuming constant follow-up time. RESULTS: Overall, malaria infection prevalence was 36.5% and was significantly higher among poorest individuals compared with the less poor (39.9% vs 33.5%, aPR=1.17; 95% CI 1.11 to 1.23) but no change in prevalence over time (trend p value <0.256). Care-seeking (61.1% vs 62.5%, aPR=0.99; 95% CI 0.95 to 1.03) and use of any medication were similar among the poorest and less poor. Poorest individuals were less likely to use Artemether-Lumefantrine or quinine for malaria treatment (18.8% vs 22.1%, aPR=0.81, 95% CI 0.72 to 0.91) while use of ITNs was lower among the poorest individuals compared with less poor (54.8% vs 57.9%; aPR=0.95; 95% CI 0.91 to 0.99), but the difference was negligible. CONCLUSIONS: Despite attainment of equity in ITN use over time, socioeconomic inequalities still existed in the distribution of malaria. This might be due to a lower likelihood of treatment with an effective antimalarial and lower use of ITNs by poorest individuals. Additional strategies are necessary to reduce socioeconomic inequities in prevention and control of malaria in endemic areas in order to achieve universal health coverage and sustainable development goals.

Sleeping arrangements and mass distribution of bed nets in six districts in central and northern Mozambique.

OBJECTIVE: Universal coverage with insecticide-treated bed nets is a cornerstone of modern malaria control. Mozambique has developed a novel bed net allocation strategy, where the number of bed nets allocated per household is calculated on the basis of household composition and assumptions about who sleeps with whom. We set out to evaluate the performance of the novel allocation strategy. METHODS: A total of 1994 households were visited during household surveys following two universal coverage bed net distribution campaigns in Sofala and Nampula provinces in 2010-2013. Each sleeping space was observed for the presence of a bed net, and the sleeping patterns for each household were recorded. The observed coverage and efficiency were compared to a simulated coverage and efficiency had conventional allocation strategies been used. A composite indicator, the product of coverage and efficiency, was calculated. Observed sleeping patterns were compared with the sleeping pattern assumptions. RESULTS: In households reached by the campaign, 93% (95% CI: 93-94%) of sleeping spaces in Sofala and 84% (82-86%) in Nampula were covered by campaign bed nets. The achieved efficiency was high, with 92% (91-93%) of distributed bed nets in Sofala and 93% (91-95%) in Nampula covering a sleeping space. Using the composite indicator, the novel allocation strategy outperformed all conventional strategies in Sofala and was tied for best in Nampula. The sleeping pattern assumptions were completely satisfied in 66% of households in Sofala and 56% of households in Nampula. The most common violation of the sleeping pattern assumptions was that male children 3-10 years of age tended not to share sleeping spaces with female children 3-10 or 10-16 years of age. CONCLUSIONS: The sleeping pattern assumptions underlying the novel bed net allocation strategy are generally valid, and net allocation using these assumptions can achieve high coverage and compare favourably with conventional allocation strategies.

Malaria rapid diagnostic tests in elimination settings--can they find the last parasite?

Rapid diagnostic tests (RDTs) for malaria have improved the availability of parasite-based diagnosis throughout the malaria-endemic world. Accurate malaria diagnosis is essential for malaria case management, surveillance, and elimination. RDTs are inexpensive, simple to perform, and provide results in 15-20 min. Despite high sensitivity and specificity for Plasmodium falciparum infections, RDTs have several limitations that may reduce their utility in low-transmission settings: they do not reliably detect low-density parasitaemia (≤200 parasites/µL), many are less sensitive for Plasmodium vivax infections, and their ability to detect Plasmodium ovale and Plasmodium malariae is unknown. Therefore, in elimination settings, alternative tools with higher sensitivity for low-density infections (e.g. nucleic acid-based tests) are required to complement field diagnostics, and new highly sensitive and specific field-appropriate tests must be developed to ensure accurate diagnosis of symptomatic and asymptomatic carriers. As malaria transmission declines, the proportion of low-density infections among symptomatic and asymptomatic persons is likely to increase, which may limit the utility of RDTs. Monitoring malaria in elimination settings will probably depend on the use of more than one diagnostic tool in clinical-care and surveillance activities, and the combination of tools utilized will need to be informed by regular monitoring of test performance through effective quality assurance.

Drug dispensing practices during implementation of artemisinin-based combination therapy at health facilities in rural Tanzania, 2002-2005.

OBJECTIVE: To assess the degree to which policy changes to artemisinin-based combination therapies (ACTs) as first-line treatment for uncomplicated malaria translate into effective ACT delivery. METHODS: Prospective observational study of drug dispensing practices at baseline and during the 3 years following introduction of ACT with sulfadoxine-pyrimethamine (SP) plus artesunate (AS) in Rufiji District, compared with two neighbouring districts where SP monotherapy remained the first-line treatment, was carried out. Demographic and dispensing data were collected from all patients at the dispensing units of selected facilities for 1 month per quarter, documenting a total of 271, 953 patient encounters in the three districts. RESULTS: In Rufiji, the proportion of patients who received a clinical diagnosis of malaria increased from 47.6% to 57.0%. A majority (75.9%) of these received SP + AS during the intervention period. Of patients who received SP + AS, 94.6% received the correct dose of both. Among patients in Rufiji who received SP, 14.2% received SP monotherapy, and among patients who received AS, 0.3% received AS monotherapy. CONCLUSIONS: The uptake of SP + AS in Rufiji was rapid and sustained. Although some SP monotherapy occurred, AS monotherapy was rare, and most received the correct dose of both drugs. These results suggest that implementation of an artemisinin combination therapy, accompanied by training, job aids and assistance in stock management, can rapidly increase access to effective antimalarial treatment.

Use of proxy measures in estimating socioeconomic inequalities in malaria prevalence.

OBJECTIVES: To present and compare socioeconomic status (SES) rankings of households using consumption and an asset-based index as two alternative measures of SES; and to compare and evaluate the performance of these two measures in multivariate analyses of the socioeconomic gradient in malaria prevalence. METHODS: Data for the study come from a survey of 557 households in 25 study villages in Tanzania in 2004. Household SES was determined using consumption and an asset-based index calculated using Principal Components Analysis on a set of household variables. In multivariate analyses of malaria prevalence, we also used two other measures of disease prevalence: parasitaemia and self-report of malaria or fever in the 2 weeks before interview. RESULTS: Household rankings based on the two measures of SES differ substantially. In multivariate analyses, there was a statistically significant negative association between both measures of SES and parasitaemia but not between either measure of SES and self-reported malaria. Age of individual, use of a mosquito net, and wall construction were negatively and significantly associated with parasitaemia, whilst roof construction was positively associated with parasitaemia. Only age remained significant when malaria self-report was used as the measure of disease prevalence. CONCLUSIONS: An asset index is an effective alternative to consumption in measuring the socioeconomic gradient in malaria parasitaemia, but self-report may be an unreliable measure of malaria prevalence for this purpose.

Fever treatment and household wealth: the challenge posed for rolling out combination therapy for malaria.

OBJECTIVE: To investigate the variation in malaria parasitaemia, reported fever, care seeking, antimalarials obtained and household expenditure by socio-economic status (SES), and to assess the implications for ensuring equitable and appropriate use of antimalarial combination therapy. METHODS: A total of 2,500 households were surveyed in three rural districts in southern Tanzania in mid-2001. Blood samples and data on SES were collected from all households. Half the households completed a detailed questionnaire on care seeking and treatment costs. Households were categorised into SES thirds based on an index of household wealth derived using principal components analysis. RESULTS: Of individuals completing the detailed survey, 16% reported a fever episode in the previous 2 weeks. People from the better-off stratum were significantly less likely to be parasitaemic, and significantly more likely to obtain antimalarials than those in the middle or poor stratum. The better treatment obtained by the better off led them to spend two to three times more than the middle and poor third spent. This reflected greater use of non-governmental organisation (NGO) facilities, which were the most expensive source of care, and higher expenditure at NGO facilities and drug stores. CONCLUSION: The coverage of appropriate malaria treatment was low in all SES groups, but the two poorer groups were particularly disadvantaged. As countries switch to antimalarial combination therapy, distribution must be targeted to ensure that the poorest groups fully benefit from these new and highly effective medicines.

Trends in antimalarial drug deployment in sub-Saharan Africa.

Antimalarial drug resistance is forcing newly developed pharmaceuticals into widespread use at an accelerating pace. To have the greatest public health impact, new pharmaceuticals will need to be deployed effectively in sub-Saharan Africa. Achieving effective antimalarial drug deployment over the short- to medium-term will require an appreciation of how drugs are currently used in Africa and the development of innovative approaches to optimize that use. Over the long-term, fundamental changes in the way that drugs are deployed will probably be required. There are many new strategies and initiatives that, to a greater or lesser degree, will influence how drugs are used. These influences may have a positive or negative effect on reducing malaria morbidity and mortality. The concept of analyzing and monitoring programmatic effectiveness allows for a more holistic understanding of these influences and allows for more unbiased, evidence-based decision making related to drug policy and deployment.

Probable locally acquired mosquito-transmitted malaria in Georgia, 1999.

In July 1999, the Centers for Disease Control and Prevention received notification of a case of malaria in a 32-year-old female native of Colquitt County, Georgia, who had no history of travel into an area where malaria transmission is endemic. An epidemiological investigation confirmed the absence of risk factors, such as blood transfusion, organ transplantation, malariotherapy, needle sharing, or past malaria infection. Active case finding revealed no other infected persons in Colquitt County. Light trapping and larvae-dipping failed to identify adult or larval anophelines; however, Colquitt County is known to be inhabited by Anopheles quadrimaculatus, a competent malaria vector. The patient's home was located near housing used by seasonal migrant workers from regions of southern Mexico and Central America where malaria is endemic, one of whom may have been the infection source. The occurrence of malaria in this patient with no risk factors, except for proximity to potentially gametocytemic hosts, suggests that this illness probably was acquired through the bite of an Anopheles species mosquito.

Malaria surveillance--United States, 1998.

PROBLEM/CONDITION: Human malaria is caused by one or more of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). The protozoa are transmitted by the bite of an infective female Anopheles species mosquito. The majority of malaria infections in the United States occur among persons who have traveled to areas with endemic transmission. Cases occasionally occur that are acquired through exposure to infected blood products, by congenital transmission, or by local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers. REPORTING PERIOD: Cases with an onset of symptoms during 1998. DESCRIPTION OF SYSTEM: Malaria cases confirmed by blood smear are reported to local and state health departments by health-care providers and laboratory staff members. Case investigations are conducted by local and state health departments, and reports are sent to CDC through the National Malaria Surveillance System (NMSS). This report uses NMSS data. RESULTS: CDC received reports of 1,227 cases of malaria with onsets of symptoms in 1998, among persons in the United States and its territories. This number represents a decrease of 20.5% from the 1,544 cases reported during 1997. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 42.8%, 37.8%, 3.5%, and 2.1% of cases, respectively. More than one species was present in seven patients (0.6% of total). The infecting species was not determined in 162 (13.2%) cases. Compared with reported cases in 1997, reported malaria cases acquired in Africa increased by 1.3% (n = 706); those acquired in Asia decreased by 52.1% (n = 239); and those acquired in the Americas decreased by 6.5% (n = 229). Of 636 U.S. civilians who acquired malaria abroad, 126 (19.8%) reportedly had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Five persons became infected in the United States. One case was congenitally acquired; one was acquired by blood transfusion; and three were isolated cases that could not be epidemiologically linked to another case. Four deaths were attributed to malaria. INTERPRETATION: The 20.5% decrease in malaria cases during 1998 compared with 1997 resulted primarily from decreases in P. vivax cases acquired in Asia among non-U.S. civilians. This decrease could have resulted from local changes in disease transmission, decreased immigration from the region, decreased travel to the region, incomplete reporting from state and local health departments, or increased use of effective antimalarial chemoprophylaxis. In a majority of reported cases, U.S. civilians who acquired infection abroad had not taken an appropriate chemoprophylaxis regimen for the country where they acquired malaria. PUBLIC HEALTH ACTIONS TAKEN: Additional information was obtained from state and local health departments and clinics concerning the four fatal cases and the five infections acquired in the United States. Persons traveling to a malarious area should take a recommended chemoprophylaxis regimen and use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and subsequently develops fever or influenza-like symptoms should seek medical care immediately; the investigation should include a blood smear for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Current recommendations concerning prevention and treatment of malaria can be obtained from CDC.

Patterns of care for childhood malaria in Zambia.

Malaria is a major cause of death among children in many parts of the world, even though simple and effective treatments exist. This study examines care-seeking patterns and barriers to appropriate treatment for Zambian children with fever or convulsions, two key symptoms of malaria. The study focuses on community perceptions of and response to febrile illness, using illness narratives as the primary data collection vehicle. The 154 detailed narratives indicate that mothers recognize fever and treat promptly, and consider chloroquine in conjunction with anti-pyretics to be the appropriate treatment. Synchronic and diachronic analyses show that most treatment begins at home, although the majority of cases are also seen in the formal health system. However, whether treated at home or taken to the health center, most children do not receive appropriate care--in this case, a 3-day course of chloroquine--because of problems of access and lack of understanding of the importance of giving the full dose. Further, those children who continue to have fever despite receiving chloroquine seldom receive the recommended second-line treatment with sulfadoxine-pyrimethamine. Most children with symptoms of convulsions are taken to the health center, but are more likely than children with simple malaria to receive traditional treatments as well.

Self-reported weapon ownership, use, and violence experience among clients accessing an inner-city sexually transmitted disease clinic.

Little is known about the extent to which people who access public health care settings own/carry weapons and experience/perpetrate acts of violence. The purpose of this study was to describe weapon ownership and violence experiences of persons attending an inner-city sexually transmitted disease clinic. Face-to-face interviews were administered to 245 clients to assess weapon ownership, types of weapons carried, and experiences as victims or perpetrators of violent acts. Overall, 43.7% reported experience of carrying a weapon at some point in their lives. More men chose to carry guns; more women chose to carry knives or mace. Participants reported experiencing alarming levels of violence in the previous year: 30.5% experienced beatings, 23.9% reported being threatened with a gun, and 18.9% reported forced, unwanted sex. Persons with a history of carrying weapons were significantly more likely to report being both victims and perpetrators of violence. Persons who experienced violence in the previous month were significantly more likely to be diagnosed with an STD. Results show that STD clinics represent yet another setting wherein interventions to curb the extent of violence might be appropriate, and strategies to assist and protect those experiencing violence are needed.

Maintenance and sustained use of insecticide-treated bednets and curtains three years after a controlled trial in western Kenya.

In large experimental trials throughout Africa, insecticide-treated bednets and curtains have reduced child mortality in malaria-endemic communities by 15%-30%. While few questions remain about the efficacy of this intervention, operational issues around how to implement and sustain insecticide-treated materials (ITM) projects need attention. We revisited the site of a small-scale ITM intervention trial, 3 years after the project ended, to assess how local attitudes and practices had changed. Qualitative and quantitative methods, including 16 focus group discussions and a household survey (n = 60), were employed to assess use, maintenance, retreatment and perceptions of ITM and the insecticide in former study communities. Families that had been issued bednets were more likely to have kept and maintained them and valued bednets more highly than those who had been issued curtains. While most households retained their original bednets, none had treated them with insecticide since the intervention trial was completed 3 years earlier. Most of those who had been issued bednets repaired them, but none acquired new or replacement nets. In contrast, households that had been issued insecticide-treated curtains often removed them. Three (15%) of the households issued curtains had purchased one or more bednets since the study ended. In households where bednets had been issued, children 10 years of age and younger were a third as likely to sleep under a net as were adults (relative risk (RR) = 0. 32; 95% confidence interval (95%CI) = 0.19, 0.53). Understanding how and why optimal ITM use declined following this small-scale intervention trial can suggest measures that may improve the sustainability of current and future ITM efforts.

A community perspective on the efficacy of malaria treatment options for children in Lundazi district, Zambia.

In 1996, Zambia's Ministry of Health made sulfadoxine-pyrimethamine (SP) available as a second-line antimalarial. SP differs from chloroquine (CQ) in ways that might affect parents' acceptance of the drug, resulting in possible delays in seeking treatment if parents perceive SP as less efficacious. A multifaceted study consisting of a rapid community ethnographic assessment to examine local attitudes and perceptions toward malaria, a 14-day in vivo drug efficacy study comparing clinical and parasitological efficacy of CQ, SP, and SP with paracetamol (PCM) in children under five, and a qualitative study examining caretakers' perceptions of drug efficacy helped to guide implementation of the new drug policy. The rapid ethnographic study indicated that the community was aware of malaria as an illness best treated with modern medicines, particularly CQ. The drug efficacy study demonstrated a 25% level of clinical failures compared to none with SP, and 30% of the children treated with CQ had either RIII or RII parasitological failures whereas none occurred in children treated with SP. Most parents perceived that their children were improving and that the drugs were working. Parents in the SP groups were most pleased and readily accepted SP as a new drug. The addition of PCM did not improve perceptions of SP efficacy, contradicting conventional wisdom regarding the need for direct antipyretic action for parents to perceive a drug as efficacious. The combined results reflected a community that was in the beginning stages of evaluating a new malaria therapy mostly unknown to them. Perceptions of efficacy of CQ were beginning to shift, indicating a readiness for accepting a new drug based on its shown biological efficacy. Parasitological and clinical failure rates reinforced the need to fully implement the changed national policy as soon as possible, and to consider a change in first-line therapy.

Malaria surveillance--United States, 1995.

PROBLEM/CONDITION: Malaria is caused by four species of Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae), which are transmitted by the bite of an infective female Anopheles sp. mosquito. Most malaria infections in the United States occur among persons who have traveled to areas with ongoing transmission. Occasionally, cases occur in the United States through exposure to infected blood products, by congenital transmission, or by local mosquito-borne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers. REPORTING PERIOD: Cases with onset of illness during 1995. DESCRIPTION OF SYSTEM: Malaria cases confirmed by blood smears are reported to local and/or state health departments by health-care providers and/or laboratory staff. Case investigations are conducted by local and/or state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS). Data from NMSS serve as the basis for this report. RESULTS: CDC received reports of 1,167 cases of malaria with onset of symptoms during 1995 among persons in the United States or one of its territories. This number represents an increase of 15% from the 1,014 cases reported for 1994. P. vivax, P. falciparum, P. malariae, and P. ovale were identified in 48.2%, 38.6%, 3.9%, and 2.2% of cases, respectively. More than one species was present in three patients (0.3% of total). The infecting species was not determined in 80 (6.9%) cases. The number of reported malaria cases acquired in Africa (n=519) remained approximately the same as in 1994 (n=517); cases acquired in Asia increased by 32.4% (n=335); and cases acquired in the Americas increased by 37.4 % (n=246). Of 591 U.S. civilians who acquired malaria abroad, 15.6% had followed a chemoprophylactic drug regimen recommended by CDC for the area where they had traveled. Nine patients became infected in the United States. Of these nine cases, five were congenitally acquired; one was acquired by organ transplantation; and one was acquired by a blood transfusion. For two of the nine cases, the source of infection was unknown. Six deaths were attributed to malaria. INTERPRETATION: The 15% increase in malaria cases in 1995 compared with 1994 resulted primarily from increases in cases acquired in Asia and the Americas, most notably a 100% increase in the number of cases reported from South America. This change could have resulted from local changes in disease transmission, travel patterns, reporting errors, or a decreased use of effective antimalarial chemoprophylaxis. In most reported cases, U.S. civilians who acquired infection abroad were not on an appropriate chemoprophylaxis regimen for the country where they acquired malaria. ACTIONS TAKEN: Additional information was obtained concerning the six fatal cases and the nine infections acquired in the United States. Malaria prevention guidelines were updated and distributed to health-care providers. Persons traveling to a malarious area should take the recommended chemoprophylaxis regimen and use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and who subsequently develops a fever or influenza-like symptoms should seek medical care; investigation should include a blood smear for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning prevention and treatment of malaria can be obtained from CDC.

Prevalence of malaria parasitemia and accuracy of microscopic diagnosis in Haiti, October 1995.

In October 1995 the Ministry of Public Health and Population in Haiti surveyed 42 health facilities for the prevalence and distribution of malaria infection. They examined 1,803 peripheral blood smears from patients with suspected malaria; the overall slide positivity rate was 4.0% (range, 0.0% to 14.3%). The rate was lowest among 1- to 4-year-old children (1.6%) and highest among persons aged 15 and older (5.5%). Clinical and microscopic diagnoses of malaria were unreliable; the overall sensitivity of microscopic diagnosis was 83.6%, specificity was 88.6%, and the predictive value of a positive slide was 22.2%. Microscopic diagnoses need to be improved, and adequate surveillance must be reestablished to identify areas where transmission is most intense. The generally low level of malaria is encouraging and suggests that intensified control efforts targeted to the areas of highest prevalence could further diminish the effect of malaria in Haiti.

Malaria surveillance -- United States, 1994.

PROBLEM/CONDITION: Malaria is caused by infection with one of four species of Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, and P. malariae ), which are transmitted by the bite of an infective female Anopheles sp. mosquito. Most malarial infections in the United States occur in persons who have traveled to areas (i.e., other countries) in which disease transmission is ongoing. However, cases are transmitted occasionally through exposure to infected blood products, by congenital transmission, or by local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to adapt prevention recommendations. REPORTING PERIOD COVERED: Cases with onset of symptoms during 1994. DESCRIPTION OF SYSTEM: Malaria cases confirmed by blood smear are reported to local and/or state health departments by health-care providers and/or laboratories. Case investigations are conducted by local and/or state health departments, and the reports are transmitted to CDC through the National Malaria Surveillance System (NMSS), which was the source of data for this report. Numbers of cases reported through NMSS may differ from those reported through other passive surveillance systems because of differences in the collection and transmission of data. RESULTS: CDC received reports of 1,014 cases of malaria with onset of symptoms during 1994 among persons in the United States or one of its territories. This number represented a 20% decrease from the 1,275 cases reported for 1993. P. vivax, P. falciparum, P. malariae, and P. ovale accounted for 44%, 44%, 4%, and 3% of cases, respectively. More than one species was present in five persons (<1% of the total number of patients). The infecting species was not determined in 50 (5%) cases. The number of reported malaria cases in U.S. military personnel decreased by 86% (i.e., from 278 cases in 1993 to 38 cases in 1994). Of the U.S. civilians who acquired malaria during travel to foreign countries, 18% had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Five persons became infected while in the United States; the infection was transmitted to two of these persons through transfusion of infected blood products. The remaining three cases, which occurred in Houston, Texas, were probably locally acquired mosquitoborne infections. Four deaths were attributed to malaria. INTERPRETATION: The 20% decrease in the number of malaria cases from 1993 to 1994 resulted primarily from an 86% decrease in cases among U.S. military personnel after withdrawal from Somalia. Because most malaria cases acquired in Somalia during 1993 resulted from infection with P. vivax, there was a proportionately greater decrease during 1994 in the number of cases caused by P. vivax relative to those caused by P. falciparum. ACTIONS TAKEN: Additional information was obtained concerning the four fatal cases and the five cases acquired in the United States. Malaria prevention guidelines were updated and distributed to health-care providers. Persons traveling to a geographic area in which malaria is endemic should take the recommended chemoprophylactic regimen and should use protective measures to prevent mosquito bites. Persons who have a fever or influenza-like illness after returning from a malarious area should seek medical care; medical evaluation should include a blood smear examination for malaria. Malarial infections can be fatal if not promptly diagnosed and treated. Recommendations concerning prevention and treatment of malaria can be obtained from CDC.

Risk of heat-related injury to disaster relief workers in a slow-onset flood disaster.

Heat-related injury or illness (HRI) occurs when the body can no longer maintain a healthy core temperature. During the 1993 Midwest floods, several risk factors HRI were present for workers involved in sandbagging activities. Medical claims filed by Illinois National Guard troops were used to identify injuries. HRI was the most frequently reported injury diagnosis, at 19.3% (23 of 119 injuries). HRI represented 16.0% of injuries to men and 41.7% of injuries to women. HRI can be influenced by high ambient temperatures, high humidity, and prolonged exertion, all of which were present in Illinois. Our results indicate that HRI is a potential problem in disaster relief situations. Further investigation using more detailed data is needed to confirm these findings. Implementation of a few simple preventive measures may decrease the impact of this problem.

School-associated violent deaths in the United States, 1992 to 1994.

OBJECTIVES: To conduct the first nationwide investigation of violent deaths associated with schools in the United States, to quantify the risk of school-associated violent death, and to identify epidemiologic features of these deaths. DESIGN: Descriptive case series. SETTING: United States, July 1, 1992, through June 30, 1994. METHODS: School-associated violent deaths were identified by study collaborators and through 2 online news databases. Police reports, medical examiners' records, and interviews with police and school officials provided detailed information about each case. RESULTS: In a 2-year period, 105 school-associated violent deaths were identified. The estimated incidence of school-associated violent death was 0.09 per 100 000 student-years. Students in secondary schools, students of minority racial and ethnic backgrounds, and students in urban school districts had higher levels of risk. The deaths occurred in communities of all sizes in 25 different states. Homicide was the predominant cause of death (n = 85 [80.9%]), and firearms were responsible for a majority (n = 81 [77.1%]) of the deaths. Most victims were students (n = 76 [72.4%]). Both victims and offenders tended to be young (median ages, 16 and 17 years, respectively) and male (82.9% and 95.6%, respectively). Approximately equal numbers of deaths occurred inside school buildings (n = 31 [29.5%]), outdoors but on school property (n = 37 [35.2%]), and at off-campus locations while the victim was in transit to or from school (n = 37 [35.2%]). Equal numbers of deaths occurred during classes or other school activities (n = 46 [43.8%]) and before or after official school activities (n = 46 [43.8%]). CONCLUSIONS: School-associated violent deaths were more common than previously estimated. The epidemiologic features of these deaths were similar to those of homicides and suicides that occur elsewhere. A comprehensive approach that addresses violent injury and death among young people at school and elsewhere in the community is suggested.

Suicide prevention from a public health perspective.

The public health approach to health problems provides a strong framework and rationale for developing and implementing suicide prevention programs. This approach consists of health-event surveillance to describe the problem, epidemiologic analysis to identify risk factors, the design and evaluation of interventions, and the implementation of prevention programs. The application of each of these components to suicide prevention is reviewed. Suggestions for improving surveillance include encouraging the use of appropriate coding, reviewing suicide statistics at the local level, collecting more etiologically useful information, and placing greater emphasis on analysis of morbidity data. For epidemiologic analysis, greater use could be made of observational studies, and uniform definitions and measures should be developed and adopted. Efforts to develop interventions must include evaluating both the process and the outcome. Finally, community suicide prevention programs should include more than one strategy and, where appropriate, should be strongly linked with the community's mental health resources. With adequate planning, coordination, and resources, and the public health approach can help reduce the emotional and economic costs imposed on society by suicide and suicidal behavior.