Disparities in Incidence of COVID-19 Among Underrepresented Racial/Ethnic Groups in Counties Identified as Hotspots During June 5-18, 2020 - 22 States, February-June 2020.

During January 1, 2020-August 10, 2020, an estimated 5 million cases of coronavirus disease 2019 (COVID-19) were reported in the United States.* Published state and national data indicate that persons of color might be more likely to become infected with SARS-CoV-2, the virus that causes COVID-19, experience more severe COVID-19-associated illness, including that requiring hospitalization, and have higher risk for death from COVID-19 (1-5). CDC examined county-level disparities in COVID-19 cases among underrepresented racial/ethnic groups in counties identified as hotspots, which are defined using algorithmic thresholds related to the number of new cases and the changes in incidence.† Disparities were defined as difference of ≥5% between the proportion of cases and the proportion of the population or a ratio ≥1.5 for the proportion of cases to the proportion of the population for underrepresented racial/ethnic groups in each county. During June 5-18, 205 counties in 33 states were identified as hotspots; among these counties, race was reported for ≥50% of cumulative cases in 79 (38.5%) counties in 22 states; 96.2% of these counties had disparities in COVID-19 cases in one or more underrepresented racial/ethnic groups. Hispanic/Latino (Hispanic) persons were the largest group by population size (3.5 million persons) living in hotspot counties where a disproportionate number of cases among that group was identified, followed by black/African American (black) persons (2 million), American Indian/Alaska Native (AI/AN) persons (61,000), Asian persons (36,000), and Native Hawaiian/other Pacific Islander (NHPI) persons (31,000). Examining county-level data disaggregated by race/ethnicity can help identify health disparities in COVID-19 cases and inform strategies for preventing and slowing SARS-CoV-2 transmission. More complete race/ethnicity data are needed to fully inform public health decision-making. Addressing the pandemic's disproportionate incidence of COVID-19 in communities of color can reduce the community-wide impact of COVID-19 and improve health outcomes.

Trends in Number and Distribution of COVID-19 Hotspot Counties - United States, March 8-July 15, 2020.

The geographic areas in the United States most affected by the coronavirus disease 2019 (COVID-19) pandemic have changed over time. On May 7, 2020, CDC, with other federal agencies, began identifying counties with increasing COVID-19 incidence (hotspots) to better understand transmission dynamics and offer targeted support to health departments in affected communities. Data for January 22-July 15, 2020, were analyzed retrospectively (January 22-May 6) and prospectively (May 7-July 15) to detect hotspot counties. No counties met hotspot criteria during January 22-March 7, 2020. During March 8-July 15, 2020, 818 counties met hotspot criteria for ≥1 day; these counties included 80% of the U.S. population. The daily number of counties meeting hotspot criteria peaked in early April, decreased and stabilized during mid-April-early June, then increased again during late June-early July. The percentage of counties in the South and West Census regions* meeting hotspot criteria increased from 10% and 13%, respectively, during March-April to 28% and 22%, respectively, during June-July. Identification of community transmission as a contributing factor increased over time, whereas identification of outbreaks in long-term care facilities, food processing facilities, correctional facilities, or other workplaces as contributing factors decreased. Identification of hotspot counties and understanding how they change over time can help prioritize and target implementation of U.S. public health response activities.

Partnership Between a Federal Agency and 4 Tribal Nations to Improve COVID-19 Response Capacities.

Upon request from tribal nations, and as part of the Centers for Disease Control and Prevention's (CDC's) emergency response, CDC staff provided both remote and on-site assistance to tribes to plan, prepare, and respond to the COVID-19 pandemic. From April 2, 2020, through June 11, 2021, CDC deployed a total of 275 staff to assist 29 tribal nations. CDC staff typically collaborated in multiple work areas including epidemiology and surveillance (86%), contact tracing (76%), infection prevention control (72%), community mitigation (72%), health communication (66%), incident command structure (55%), emergency preparedness (38%), and worker safety (31%). We describe the activities of CDC staff in collaboration with 4 tribal nations, Northern Cheyenne, Hoopa Valley, Shoshone-Bannock, and Oglala Sioux Tribe, to combat COVID-19 and lessons learned from the engagement.

Delayed onset of malaria--implications for chemoprophylaxis in travelers.

BACKGROUND: Most antimalarial agents used by travelers act on the parasite's blood stage and therefore do not prevent late-onset illness, particularly that due to species that cause relapsing malaria. We examined the magnitude of this problem among Israeli and American travelers. METHODS: We examined malaria surveillance data from Israel and the United States to determine the traveler's destination, the infecting species, the type of chemoprophylaxis used, and the incubation period. RESULTS: In Israel, from 1994 through 1999, there were 300 cases of malaria among returning travelers in which one species of plasmodium could be identified. In 134 of these cases (44.7 percent), the illness developed more than two months after the traveler's return; nearly all of these cases were due to infection with Plasmodium vivax or P. ovale. In 108 of the 134 cases (80.6 percent), the patient had used an antimalarial regimen according to national guidelines. In the United States, from 1992 through 1998, there were 2822 cases of malaria among travelers in which the cause could be evaluated. Late illness developed in 987 (35.0 percent) of these travelers. The infection was due to P. vivax in 811 travelers, P. ovale in 66, P. falciparum in 59, and P. malariae in 51; 614 (62.2 percent) of those with late-onset illness had appropriately taken an effective antimalarial agent. CONCLUSIONS: In more than one third of malaria-infected travelers, the illness developed more than two months after their return. Most of these late-onset illnesses are not prevented by the commonly used and effective blood schizonticides. Agents that act on the liver phase of malaria parasites are needed for more effective prevention of malaria in travelers.

Locally acquired mosquito-transmitted malaria: a guide for investigations in the United States.

Recent outbreaks of locally acquired mosquito-transmitted malaria in the United States demonstrate the continued risk for reintroduction of the disease. Since 1957, when CDC's Malaria Branch started conducting malaria surveillance, 63 outbreaks have occurred, constituting 156 cases (annual range: 1-32) that were a result of locally acquired mosquitoborne transmission. This report describes the steps that should be taken to 1) investigate a case that might have been acquired locally, 2) prevent a small focus of malaria cases from becoming a source of sustained transmission, and 3) inform clinicians regarding the process of an investigation so they can effectively address concerns and questions from patients. Although these locally acquired mosquito-transmitted outbreaks frequently involve only a limited number of infected persons, they frequently raise concerns in the community and require substantial public health resources. For example, as a result of the most recent local outbreak of eight malaria cases in Florida in 2003, reverse 911 telephone calls (a community notification system) were made to approximately 300,000 residents; insect repellent, postcards, flyers, and posters in multiple languages were distributed; public announcements were made through the media and to schools and homeless shelters; and notifications were sent to local hospitals and physicians to inform residents of that community. When a local health department investigates a potential locally acquired mosquito-transmitted case, the systematic inquiry should include epidemiologic, environmental, and laboratory components. Local and state health departments inquiring about the proper approach to investigate and control a potential locally acquired case frequently request urgent assistance and tools from CDC. This report provides a starting point for such investigations to local and state health departments by providing them with the tools necessary to initiate an investigation.

Atovaquone-proguanil: report from the CDC expert meeting on malaria chemoprophylaxis (II).

The fixed dose combination of atovaquone and proguanil hydrochloride, marketed under the trade name Malarone, is the most recently approved agent in North America for the prevention and treatment of chloroquine- and multi-drug resistant Plasmodium falciparum malaria. In both adult and pediatric populations, atovaquone-proguanil demonstrates consistently high protective efficacy against P. falciparum, and in treatment trials, cure rates exceed 93%. Only a handful of genetically confirmed treatment failures have been reported to date. Atovaquone-proguanil has an excellent safety profile during both prophylaxis and treatment courses, with severe adverse events rarely reported. This topical review will examine the evidence behind the current indications for use of atovaquone-proguanil, and will summarize the current body of literature surrounding safety and tolerability.

Safety and toxicity of sulfadoxine/pyrimethamine: implications for malaria prevention in pregnancy using intermittent preventive treatment.

Plasmodium falciparum infection during pregnancy is strongly associated with maternal anaemia and low birth weight, contributing to substantial morbidity and mortality in sub-Saharan Africa. Intermittent preventive treatment in pregnancy with sulfadoxine/pyrimethamine (IPTp-SP) has been one of the most effective approaches to reduce the burden of malaria during pregnancy in Africa. IPTp-SP is based on administering >or=2 treatment doses of sulfadoxine/pyrimethamine to pregnant women at predefined intervals after quickening (around 18-20 weeks). Randomised, controlled trials have demonstrated decreased rates of maternal anaemia and low birth weight with this approach. The WHO currently recommends IPTp-SP in malaria-endemic areas of sub-Saharan Africa. However, implementation has been suboptimal in part because of concerns of potential drug toxicities. This review evaluates the toxicity data of sulfadoxine/pyrimethamine, including severe cutaneous adverse reactions, teratogenicity and alterations in bilirubin metabolism. Weekly sulfadoxine/pyrimethamine prophylaxis is associated with rare but potentially fatal cutaneous reactions. Fortunately, sulfadoxine/pyrimethamine use in IPTp programmes in Africa, with 2-4 treatment doses over 6 months, has been well tolerated in multiple IPTp trials. However, sulfadoxine/pyrimethamine should not be administered concurrently with cotrimoxazole given their redundant mechanisms of action and synergistic worsening of adverse drug reactions. Therefore, HIV-infected pregnant women in malaria endemic areas who are already receiving cotrimoxazole prophylaxis should not also receive IPTp-SP. Although folate antagonist use in the first trimester is associated with neural tube defects, large case-control studies have demonstrated that sulfadoxine/pyrimethamine administered as IPTp (exclusively in the second and third trimesters and after organogenesis) does not result in an increased risk of teratogenesis. Folic acid supplementation is recommended for all pregnant women to reduce the rate of congenital anomalies but high doses of folic acid (5 mg/day) may interfere with the antimalarial efficacy of sulfadoxine/pyrimethamine. However, the recommended standard dose of folic acid supplementation (0.4 mg/day) does not affect antimalarial efficacy and may provide the optimal balance to prevent neural tube defects and maintain the effectiveness of IPTp-SP. No clinical association between sulfadoxine/pyrimethamine use and kernicterus has been reported despite the extensive use of sulfadoxine/pyrimethamine and related compounds to treat maternal malaria and congenital toxoplasmosis in near-term pregnant women and newborns. Although few drugs in pregnancy can be considered completely safe, sulfadoxine/pyrimethamine - when delivered as IPTp - has a favourable safety profile. Improved pharmacovigilance programmes throughout Africa are now needed to confirm its safety as access to IPTp-SP increases. Given the documented benefits of IPTp-SP in malaria endemic areas of Africa, access to this treatment for pregnant women should continue to expand.

Malaria and anaemia among pregnant women at first antenatal clinic visit in Kisumu, western Kenya.

OBJECTIVE: To determine the prevalence of malaria and anaemia among urban and peri-urban women attending their first antenatal clinic (ANC) in an area of perennial malaria transmission. METHODS: Between November 2003 and May 2004 we screened first ANC attenders for malaria and anaemia in a large urban hospital in Kisumu (western Kenya) and interviewed them to obtain demographic and medical information. RESULTS: Among the 685 study participants, prevalence of malaria parasitaemia was 18.0%, prevalence of any anaemia (haemoglobin < 11 g/dl) was 69.1% and prevalence of moderate anaemia was (haemoglobin < 8 g/dl) 11.8%. Sixteen women were hospitalized during pregnancy, eight because of malaria. In multivariate analysis, young age, living in a house with mud walls, a visit to rural area, peri-urban residence, second trimester of pregnancy and Luo ethnicity were significant risk factors for malaria parasitaemia. Malaria was an important risk factor for any and moderate anaemia; use of an insecticide-treated net (ITN) was a protective factor for any anaemia. Married women with a higher level of education, better-quality housing and full-time employment were more likely to use an ITN. CONCLUSION: Malaria and anaemia are established problems by the time of the first ANC visit. Mechanisms to deliver ITNs to women of child-bearing age before they become pregnant need to be explored. Early ANC visits are warranted in order for women to benefit from policies aimed at reducing the burden of malaria and anaemia.

Assessing malaria burden during pregnancy in Mali.

Malaria infection during pregnancy is associated with adverse consequences including low birth weight (LBW) and maternal anemia, particularly in primigravidae and secundigravidae. In preparation for a clinical trial of the efficacy of chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) containing prevention regimens during pregnancy, we conducted a one-year cross sectional study in Koro and Bandiagara, Mali using an assessment methodology developed by the Centers for Disease Control and Prevention (CDC) to generate basic data on malarial burden during pregnancy. Two hundred and sixty-one and 192 women were enrolled in Koro and Bandiagara, respectively. Rates of placental parasitemia were 17.1 and 42.3% in Koro and Bandiagara, respectively, despite high (70-80%) use of preventive medication (mainly CQ). Low gravidity (1st and 2nd pregnancies) was associated with peripheral (p<0.001) and placental (p<0.001) malaria only in Bandiagara, whereas it was associated with low birth weight in both sites (p<0.001 in Koro and p=0.002 in Bandiagara). First and second pregnancies were the most important characteristics associated with placental malaria (RR=2.78, 95%CI 1.81-4.29) and (ARR=2.06, 95%CI 1.03-4.15) and low birth weight (RR=4.26, 95%CI 2.50-7.27) and (ARR=4.51, 95%CI 2.55-8.00). Birth during the rainy season was associated with placental infection in univariate analysis. Characteristics such as younger age, having fever during pregnancy, and unmarried status were associated with low birth weight only in univariate analysis and singleton premature delivery and low gravidity were associated with low birth weight in both univariate and multivariate analysis. Data from this assessment demonstrated the high burden of malaria during pregnancy in Mali. Results had been used by researchers as local reference data and by ministry of health for to stop recommending CQ prophylaxis. The methodology could be used by other malaria-endemic countries to direct their national malaria program efforts.

Treatment of malaria in the United States: a systematic review.

CONTEXT: Many US clinicians and laboratory personnel are unfamiliar with the diagnosis and treatment of malaria. OBJECTIVES: To examine the evidence base for management of uncomplicated and severe malaria and to provide clinicians with practical recommendations for the diagnosis and treatment of malaria in the United States. EVIDENCE ACQUISITION: Systematic MEDLINE search from 1966 to 2006 using the search term malaria (with the subheadings congenital, diagnosis, drug therapy, epidemiology, and therapy). Additional references were obtained from searching the bibliographies of pertinent articles and by reviewing articles suggested by experts in the treatment of malaria in North America. EVIDENCE SYNTHESIS: Important measures to reduce morbidity and mortality from malaria in the United States include the following: obtaining a travel history, considering malaria in the differential diagnosis of fever based on the travel history, and prompt and accurate diagnosis and treatment. Chloroquine remains the treatment of choice for Plasmodium falciparum acquired in areas without chloroquine-resistant strains. In areas with chloroquine resistance, a combination of atovaquone and proguanil or quinine plus tetracycline or doxycycline or clindamycin are the best treatment options. Chloroquine remains the treatment of choice for all other malaria species, with the exception of P vivax acquired in Indonesia or Papua New Guinea, in which case atovaquone-proguanil is best, with mefloquine or quinine plus tetracycline or doxycycline as alternatives. Quinidine is currently the recommended treatment for severe malaria in the United States because the artemisinins are not yet available. Severe malaria occurs when a patient with asexual malaria parasitemia, and no other confirmed cause of symptoms, has 1 or more designated clinical or laboratory findings. The only adjunctive measure recommended in severe malaria is exchange transfusion. CONCLUSIONS: Malaria remains a diagnostic and treatment challenge for US clinicians as increasing numbers of persons travel to and emigrate from malarious areas. A strong evidence base exists to help clinicians rapidly initiate appropriate therapy and minimize the major mortality and morbidity burdens caused by this disease.

Randomized trial of 2-dose versus monthly sulfadoxine-pyrimethamine intermittent preventive treatment for malaria in HIV-positive and HIV-negative pregnant women in Malawi.

BACKGROUND: Intermittent preventive treatment during pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) decreases placental malaria parasitemia and associated maternal anemia, premature delivery, and low birth weight. However, the optimal regimen in the setting of a high prevalence of human immunodeficiency virus (HIV) infection remains unclear. METHODS: In Malawi, where the efficacy of SP for the treatment of malaria in children is decreasing, we conducted a randomized, nonblinded study to compare the efficacy of monthly SP IPTp with a 2-dose regimen for the prevention of placental parasitemia in HIV-positive and -negative primigravid and secundigravid women. RESULTS: Of HIV-positive women, 7.8% who received monthly SP had placental malaria, compared with 21.5% of those who received 2-dose SP (relative risk [RR], 0.36 [95% confidence interval {CI}, 0.17-0.79]). Of HIV-negative women, 2.3% who received monthly SP and 6.3% who received 2-dose SP had placental malaria (RR, 0.37 [95% CI, 0.11-1.19]). Less than 1% of women reported adverse drug reactions, with no increase in HIV-positive women or those who received monthly SP. CONCLUSIONS: In HIV-positive pregnant women, monthly SP IPTp is more efficacious than a 2-dose regimen in preventing placental malaria. The study also demonstrates the continued efficacy of SP for the prevention of placental malaria, even in the face of its decreasing efficacy for the treatment of malaria in children. In areas with intense transmission of falciparum malaria and a high prevalence of HIV infection, monthly SP IPTp should be adopted.

Primaquine: report from CDC expert meeting on malaria chemoprophylaxis I.

Primaquine phosphate has been used for preventing relapse of Plasmodium vivax and P. ovale malaria since the early 1950s, based on its ability to kill latent (hypnozoite) and developing liver stages of these parasites. There are three uses for primaquine in malaria: radical cure of established infection with P. vivax or P. ovale malaria; presumptive anti-relapse therapy (PART; terminal prophylaxis) in persons with extensive exposure to these parasites; and primary prophylaxis against all malaria species. All persons for whom primaquine is being considered must have a glucose-6-phosphate dehydrogenase (G6PD) enzyme level checked before use, and persons who have a deficiency of G6PD must not take primaquine for prophylaxis or PART. The recommended adult dose for PART based on clinical trials and expert opinion is 30 mg base daily for 14 days, started on return from a malarious region and overlapping with a blood schizonticide. The adult dose for primary prophylaxis is 30 mg daily begun 1 day before travel and continued for 7 days after return. This review will examine the evidence for these recommendations.

Malaria prevention during pregnancy: assessing the disease burden one year after implementing a program of intermittent preventive treatment in Koupela District, Burkina Faso.

The World Health Organization recommends that pregnant women in malaria-endemic areas receive >or= 2 doses of intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp/SP) in the second and third trimesters of pregnancy to prevent maternal anemia, placental parasitemia, and low birth weight (LBW). In 2001, a program evaluation in Koupéla District, Burkina Faso demonstrated that despite widespread use of chloroquine chemoprophylaxis, the burden of malaria during pregnancy remained high. In 2003, the Burkina Faso Ministry of Health piloted a program of IPTp/SP (three doses) and accelerated distribution of insecticide-treated nets (ITN) to pregnant women in Koupéla District. In 2004, a follow-up program evaluation was conducted. Coverage with >or= 1 doses of IPTp/SP was high among women attending antenatal clinics (ANCs) (96.2%) and delivery units (DUs) (93.5%); ITN ownership was moderately high (ANC = 53.9%, DU = 61.6%). In multivariate analysis, >or= 1 dose of IPTp/SP was associated with a significant reduction in the prevalence of peripheral parasitemia at ANCs (risk ratio [RR] = 0.49, P = 0.008), >or= 2 doses of IPTp/SP were associated with a reduction in the prevalence of placental parasitemia (RR = 0.56, P = 0.02), and three doses of IPTp/SP were associated with a reduced risk of LBW (RR = 0.51, P = 0.04). The proportions of women at ANCs with peripheral parasitemia and anemia were significantly lower in 2004 than in 2001 (RR = 0.53, P = 0.001 and RR = 0.78, P = 0.003, respectively). The proportions of women at DUs with peripheral and placental parasitemia were also significantly lower in 2004 than in 2001 (RR = 0.66, P < 0.0001 and RR = 0.71, P = 0.0002, respectively). These data suggest that a package of IPTp/SP and ITNs is effective in reducing the burden of malaria during pregnancy in Burkina Faso.

What Do We Know About Chagas Disease in the United States?

Chagas disease, caused by the parasite Trypanosoma cruzi, affects more than 5 million people worldwide leading to serious heart and gastrointestinal disease in a proportion of chronically infected patients. Important modes of transmission include vector-borne, congenital, and via blood transfusion or organ transplant from an infected donor. Vector-borne transmission of Chagas disease occurs in the Americas, including the southern half of North America, where the specific vector insects (triatomines), T. cruzi, and infected reservoir mammalian hosts are found. In the United States, there are estimated to be at least 300,000 cases of chronic Chagas disease among people originally from countries of Latin America where Chagas disease is endemic. Fewer than 30 cases of locally acquired infection have been documented in the United States, although a sylvatic transmission cycle has been known to exist in this country for at least a century. Studies defining risks for locally acquired infection and effective prevention strategies are needed to help prevent domestic transmission of T. cruzi To help address Chagas disease in the United States, improved health-care provider awareness and knowledge, better tools for screening and diagnosing patients, and wider availability of treatment drugs are needed.

Malaria-related deaths among U.S. travelers, 1963-2001.

Nearly 1500 malaria cases occur each year in the United States; approximately 60% are among U.S. travelers. Despite the availability of sophisticated medical care, malaria-related deaths continue to occur. The authors reviewed all 185 fatal cases between 1963 and 2001 that were reported to the National Malaria Surveillance System: 123 (66.5%) occurred among U.S. travelers, and of these, 114 (92.7%) were attributed to Plasmodium falciparum. Failure to take or adhere to recommended chemoprophylaxis, to promptly seek medical care for post-travel illness, and to promptly diagnose and treat suspected malaria all contributed to fatal outcomes. Health care providers need to take a travel history, obtain a blood film for suspected malaria, and use the 24-hour malaria management advice available through the Centers for Disease Control and Prevention (CDC) Malaria Hotline (770-488-7788) or the CDC Malaria Web site (http://www.cdc.gov/Malaria). Hospitals must maintain intravenous quinidine gluconate on formulary because it is the only drug available to treat severe malaria in the United States.

Malaria surveillance--United States, 1999.

PROBLEM/CONDITION: Malaria is caused by four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). Malaria is transmitted by the bite of an infective female Anopheles sp. mosquito. The majority of malaria infections in the United States occur in persons who have traveled to areas with ongoing transmission. In the United States, cases can occur through exposure to infected blood products, by congenital transmission, or locally through mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers. PERIOD COVERED: Cases with onset of illness during 1999. DESCRIPTION OF SYSTEM: Malaria cases confirmed by blood films are reported to local and state health departments by health-care providers or laboratory staff. Case investigations are conducted by local and 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 1,540 cases of malaria with an onset of symptoms during 1999 among persons in the United States or one of its territories. This number represents an increase of 25.5% from the 1,227 cases reported for 1998. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 46.0%, 30.7%, 4.6%, and 3.6% of cases, respectively. More than one species was present in 12 patients (0.8% of total). The infecting species was unreported or undetermined in 223 (14.5%) cases. The number of reported malaria cases acquired in Africa increased 27.6% (n = 901), compared with 1998, and an increase of 2.9% (n = 246) occurred in cases acquired in Asia, compared with 1998. Cases from the Americas increased by 19.7% (n = 274) from 1998. Of 831 U.S. civilians who acquired malaria abroad, 159 (19.1%) reported that they had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Three patients became infected in the United States, all through probable local mosquitoborne transmission. Five deaths were attributed to malaria, all caused by P. falciparum. INTERPRETATION: The 25.5% increase in malaria cases in 1999, compared with 1998, resulted primarily from increases in cases acquired in Africa and the Americas. This increase is possibly related to a change in the system by which states report to CDC, but it could also have resulted from local changes in disease transmission, increased travel to these regions, improved reporting to state and local health departments, or a decreased use of effective antimalarial chemoprophylaxis. In the majority of reported cases, U.S. civilians who acquired infection abroad were not on an appropriate chemoprophylaxis regimen for the country where they acquired malaria. PUBLIC HEALTH ACTIONS: Additional information was obtained concerning the five fatal cases and the three infections acquired in the United States. The NMSS surveillance form was modified to gather more detailed information regarding compliance with prescribed chemoprophylaxis regimens. Persons traveling to a malarious area should take one of the recommended chemoprophylaxis regimens appropriate to the region of travel, and travelers should 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 immediately; investigation should include a blood-film test for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning prevention of malaria can be obtained from CDC.

Malaria surveillance--United States, 2001.

PROBLEM/CONDITION: Malaria is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). These parasites are transmitted by the bite of an infective female Anopheles sp. mosquito. The majority of malaria infections in the United States occur among persons who have traveled to areas with ongoing transmission. In the United States, cases can occur 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. PERIOD COVERED: This report covers cases with onset of illness in 2001. DESCRIPTION OF SYSTEM: Malaria cases confirmed by blood film are reported to local and state health departments by health-care providers or laboratory staff. Case investigations are conducted by local and 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 1,383 cases of malaria with an onset of symptoms in 2001 among persons in the United States or one of its territories. This number represents a decrease of 1.4% from the 1,402 cases reported for 2000. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 50.1%, 27.8%, 4.5%, and 3.6% of cases, respectively. Fourteen patients (1.0% of total) were infected by >/=2 species. The infecting species was unreported or undetermined in 179 (12.9%) cases. Compared with 2000, the number of reported malaria cases acquired in Africa increased by 13.2% (n = 886), whereas the number of cases acquired in Asia (n = 163) and the Americas (n = 240) decreased by 31.5% and 11.4%, respectively. Of 891 U.S. civilians who acquired malaria abroad, 180 (20.2%) reported that they had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Two patients became infected in the United States, one through congenital transmission and one whose infection cannot be linked epidemiologically to secondary cases. Eleven deaths were attributed to malaria, 10 caused by P. falciparum and one caused by P. ovale. INTERPRETATION: The 1.4% decrease in malaria cases in 2001, compared with 2000, resulted primarily from a decrease in cases acquired in Asia and the Americas, but this decrease was offset by an increase in the number of cases acquired in Africa. This decrease probably represents year-to-year variation in malaria cases, but also could have resulted from local changes in disease transmission, decreased travel to malaria-endemic regions, fluctuation in reporting to state and local health departments, or an increased use of effective antimalarial chemoprophylaxis. In the majority of reported cases, U.S. civilians who acquired infection abroad were not on an appropriate chemoprophylaxis regimen for the country in which they acquired malaria. PUBLIC HEALTH ACTIONS: Additional information was obtained concerning the 11 fatal cases and the two infections acquired in the United States. Persons traveling to a malarious area should take one of the recommended chemoprophylaxis regimens appropriate for the region of travel, and travelers should 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 immediately and report their travel history to the clinician; investigation should include a blood-film test for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning malaria prevention can be obtained from CDC by calling the Malaria Hotline at 770-488-7788 or by accessing CDC's Internet site at http://www.cdc.gov/travel.

Failure of a chloroquine chemoprophylaxis program to adequately prevent malaria during pregnancy in Koupéla District, Burkina Faso.

In West Africa, administration of chloroquine chemoprophylaxis during pregnancy is common, but little is known about its impact on Plasmodium falciparum infection during pregnancy. Therefore, cross-sectional studies in antenatal care clinics (ANCs) and delivery units (DUs) were conducted in Koupéla District, Burkina Faso. Chloroquine chemoprophylaxis was reported by 69% of 597 pregnant women at ANCs and by 93% of 853 women in DUs. P. falciparum peripheral parasitemia was identified in 29% of women at both ANCs and DUs. Placental parasitemia was identified in 22% of delivering women and was strongly associated with low birth weight (LBW) (risk ratio [RR], 1.7; 95% confidence interval [CI], 1.2-2.4) and prematurity (RR, 2.9; 95% CI, 1.6-5.4). In multivariate analysis, use of chemoprophylaxis was not associated with a reduction in the prevalence of placental parasitemia, LBW, or prematurity. Despite the high reported chloroquine chemoprophylaxis coverage, peripheral and placental malaria rates remain high and are associated with known adverse outcomes during pregnancy, including maternal anemia, prematurity, and LBW. Alternative prevention strategies, such as use of insecticide-treated mosquito nets and intermittent preventive treatment with more-effective antimalarials, are needed.

The burden of co-infection with human immunodeficiency virus type 1 and malaria in pregnant women in sub-saharan Africa.

In sub-Saharan Africa, human immunodeficiency virus (HIV) and malaria are among the leading causes of morbidity during pregnancy. We reviewed available information collected since the first report 15 years ago that HIV impaired the ability of pregnant women to control malaria parasitemia. Results from 11 studies showed that HIV-infected women experienced consistently more peripheral and placental malaria (summary relative risk = 1.58 and 1.66, respectively), higher parasite densities, and more febrile illnesses, severe anemia, and adverse birth outcomes than HIV-uninfected women, particularly in multigravidae. Thus, HIV alters the typical gravidity-specific pattern of malaria risk by shifting the burden from primarily primigravidae and secundigravidae to all pregnant women. The proportional increase of malaria during pregnancy attributable to HIV was estimated to be 5.5% and 18.8% for populations with HIV prevalences of 10% and 40%, respectively. Maternal malaria was associated with a two-fold higher HIV-1 viral concentrations. Three studies investigating whether placental malaria increased mother-to-child HIV-1 transmission showed conflicting results, possibly reflecting a complex balance between placental malarial immune responses and stimulation of HIV-1 viral replication. Further investigations of interactions between antiretroviral drugs, prophylaxis with cotrimoxazole, and antimalarial drugs in pregnant women are urgently needed. Although much has been learned in the past 15 years about the interaction between malaria and HIV-1 during pregnancy, many issues still require further information to improve our understanding. There is a clear need to strengthen the deployment of existing malaria and HIV prevention and intervention measures for pregnant women.