William Nichols, Librarian

Evidence summary

Malaria is a parasitic infection that causes significant morbidity and mortality worldwide, with more than 500 million people becoming severely ill every year.² For pregnant women, malarial infection can be severe, with high fevers, chills, and anemia leading to increased risk of poor maternal and fetal outcomes—including death. Pregnant women are also more likely to become infected and to develop more severe disease—they attract twice as many mosquitoes as nonpregnant women and have a relative immuno-suppression.³

TABLE
Antimalarials for prophylaxis: Chloroquine, mefloquine are best choices during pregnancy

Chemoprophylaxis lowers rates of maternal infection

Although prophylaxis for pregnant patients traveling to malarial regions is a public concern, data for decision-making must be extrapolated from the available evidence, which is based primarily on women living in endemic areas. In a Cochrane systematic review, antimalarials were found to decrease the incidence of maternal infections (relative risk [RR]=0.27; 95% confidence interval [CI], 0.17–0.44) and reduce maternal anemia (RR=0.62; 95% CI, 0.50–0.78) in low-parity women—ie, during a first or second pregnancy.³

In low-parity women, these drugs were also found to decrease perinatal death (RR=0.73; 95% CI, 0.53–0.99) and low birth weight (RR=0.57; 95% CI, 0.46–0.72) associated with malarial infection. When used in all parity groups, antimalarials were somewhat less effective, yet still reduced maternal infections (RR=0.53; 95% CI, 0.33–0.86); the effects were similar with all antimalarials tested.^3,4

Chloroquine, mefloquine are safe in pregnancy, doxycycline is not

While chemoprophylaxis in pregnancy appears efficacious, a major question remains—which agents are safest for both the woman and fetus? Some drugs routinely used in nonpregnant individuals should not be offered to pregnant women because of known direct effects on the fetus. Doxycycline is teratogenic, and primaquine poses a significant risk of fetal intravascular hemolysis in G6PD-deficient fetuses.⁵ Other drugs, such as atovaquone/proguanil and artesunate, are not well studied in pregnancy, and therefore are not recommended for use unless other options are not available.^2,6

Among drugs that are well studied and without known direct fetal-damaging effects, adverse drug reaction profiles can guide use based on disease prevalence and drug-resistance patterns.

• Chloroquine is widely used because it is inexpensive and well tolerated, with only pruritus, mouth ulcers, and gastrointestinal upset as the most common adverse effects.
• Mefloquine is usually well tolerated, but can cause dose-related neuropsychiatric effects; it is contraindicated in those with a history of epilepsy or psychiatric disease.
• Sulfadoxine and pyrimethamine are not normally used as prophylaxis for any patient, due to the risk of toxic epidermal necrolysis and Stevens-Johnson syndrome, and the possible risk of jaundice and kernicterus if used in the third trimester of pregnancy.
• Quinine, which can be used for treatment or prophylaxis, may cause hypoglycemia, an effect that is more pronounced during pregnancy and requires close monitoring of blood glucose levels.^5,7

Given these reaction profiles, chloroquine or mefloquine are usually the best choice with their superior safety and efficacy.

Figure
Best protection: Avoidance

Recommendations from others

The World Health Organization (WHO) recommends pregnant women avoid travel to malarial regions. If travel is required, WHO recommends chloroquine as first-line prophylaxis in pregnancy (plus proguanil if the region exhibits emerging chloroquine resistance). In areas with proven chloroquine resistance, mefloquine is the drug of choice. Other antimalarials—such as quinine, pyrimethamine, sulfadoxine, and artesunate—should not be withheld if the preferred drugs are not available, or if the infection is life-threatening.²

The Centers for Disease Control and Prevention (CDC) also recommends avoiding travel to malaria-endemic regions during pregnancy, but if travel is necessary, the CDC advises use of chloroquine (or mefloquine in regions with chloroquine resistance). The CDC discourages the use of atovaquone/proguanil, doxycycline, and primaquine, due to known adverse fetal effects or inadequate experience in pregnancy.⁶

Acknowledgments

The opinions and assertions contained herein are the private views of the authors and not to be construed as official, or as reflecting the views of the US Air Force Medical Service or the US Air Force at large.

Evidence summary

Malaria is a parasitic infection that causes significant morbidity and mortality worldwide, with more than 500 million people becoming severely ill every year.² For pregnant women, malarial infection can be severe, with high fevers, chills, and anemia leading to increased risk of poor maternal and fetal outcomes—including death. Pregnant women are also more likely to become infected and to develop more severe disease—they attract twice as many mosquitoes as nonpregnant women and have a relative immuno-suppression.³

TABLE
Antimalarials for prophylaxis: Chloroquine, mefloquine are best choices during pregnancy

Chemoprophylaxis lowers rates of maternal infection

Although prophylaxis for pregnant patients traveling to malarial regions is a public concern, data for decision-making must be extrapolated from the available evidence, which is based primarily on women living in endemic areas. In a Cochrane systematic review, antimalarials were found to decrease the incidence of maternal infections (relative risk [RR]=0.27; 95% confidence interval [CI], 0.17–0.44) and reduce maternal anemia (RR=0.62; 95% CI, 0.50–0.78) in low-parity women—ie, during a first or second pregnancy.³

In low-parity women, these drugs were also found to decrease perinatal death (RR=0.73; 95% CI, 0.53–0.99) and low birth weight (RR=0.57; 95% CI, 0.46–0.72) associated with malarial infection. When used in all parity groups, antimalarials were somewhat less effective, yet still reduced maternal infections (RR=0.53; 95% CI, 0.33–0.86); the effects were similar with all antimalarials tested.^3,4

Chloroquine, mefloquine are safe in pregnancy, doxycycline is not

While chemoprophylaxis in pregnancy appears efficacious, a major question remains—which agents are safest for both the woman and fetus? Some drugs routinely used in nonpregnant individuals should not be offered to pregnant women because of known direct effects on the fetus. Doxycycline is teratogenic, and primaquine poses a significant risk of fetal intravascular hemolysis in G6PD-deficient fetuses.⁵ Other drugs, such as atovaquone/proguanil and artesunate, are not well studied in pregnancy, and therefore are not recommended for use unless other options are not available.^2,6

Among drugs that are well studied and without known direct fetal-damaging effects, adverse drug reaction profiles can guide use based on disease prevalence and drug-resistance patterns.

• Chloroquine is widely used because it is inexpensive and well tolerated, with only pruritus, mouth ulcers, and gastrointestinal upset as the most common adverse effects.
• Mefloquine is usually well tolerated, but can cause dose-related neuropsychiatric effects; it is contraindicated in those with a history of epilepsy or psychiatric disease.
• Sulfadoxine and pyrimethamine are not normally used as prophylaxis for any patient, due to the risk of toxic epidermal necrolysis and Stevens-Johnson syndrome, and the possible risk of jaundice and kernicterus if used in the third trimester of pregnancy.
• Quinine, which can be used for treatment or prophylaxis, may cause hypoglycemia, an effect that is more pronounced during pregnancy and requires close monitoring of blood glucose levels.^5,7

Given these reaction profiles, chloroquine or mefloquine are usually the best choice with their superior safety and efficacy.

Figure
Best protection: Avoidance

Recommendations from others

The World Health Organization (WHO) recommends pregnant women avoid travel to malarial regions. If travel is required, WHO recommends chloroquine as first-line prophylaxis in pregnancy (plus proguanil if the region exhibits emerging chloroquine resistance). In areas with proven chloroquine resistance, mefloquine is the drug of choice. Other antimalarials—such as quinine, pyrimethamine, sulfadoxine, and artesunate—should not be withheld if the preferred drugs are not available, or if the infection is life-threatening.²

The Centers for Disease Control and Prevention (CDC) also recommends avoiding travel to malaria-endemic regions during pregnancy, but if travel is necessary, the CDC advises use of chloroquine (or mefloquine in regions with chloroquine resistance). The CDC discourages the use of atovaquone/proguanil, doxycycline, and primaquine, due to known adverse fetal effects or inadequate experience in pregnancy.⁶

Acknowledgments

The opinions and assertions contained herein are the private views of the authors and not to be construed as official, or as reflecting the views of the US Air Force Medical Service or the US Air Force at large.

Evidence summary

Malaria is a parasitic infection that causes significant morbidity and mortality worldwide, with more than 500 million people becoming severely ill every year.² For pregnant women, malarial infection can be severe, with high fevers, chills, and anemia leading to increased risk of poor maternal and fetal outcomes—including death. Pregnant women are also more likely to become infected and to develop more severe disease—they attract twice as many mosquitoes as nonpregnant women and have a relative immuno-suppression.³

TABLE
Antimalarials for prophylaxis: Chloroquine, mefloquine are best choices during pregnancy

Chemoprophylaxis lowers rates of maternal infection

Although prophylaxis for pregnant patients traveling to malarial regions is a public concern, data for decision-making must be extrapolated from the available evidence, which is based primarily on women living in endemic areas. In a Cochrane systematic review, antimalarials were found to decrease the incidence of maternal infections (relative risk [RR]=0.27; 95% confidence interval [CI], 0.17–0.44) and reduce maternal anemia (RR=0.62; 95% CI, 0.50–0.78) in low-parity women—ie, during a first or second pregnancy.³

In low-parity women, these drugs were also found to decrease perinatal death (RR=0.73; 95% CI, 0.53–0.99) and low birth weight (RR=0.57; 95% CI, 0.46–0.72) associated with malarial infection. When used in all parity groups, antimalarials were somewhat less effective, yet still reduced maternal infections (RR=0.53; 95% CI, 0.33–0.86); the effects were similar with all antimalarials tested.^3,4

Chloroquine, mefloquine are safe in pregnancy, doxycycline is not

While chemoprophylaxis in pregnancy appears efficacious, a major question remains—which agents are safest for both the woman and fetus? Some drugs routinely used in nonpregnant individuals should not be offered to pregnant women because of known direct effects on the fetus. Doxycycline is teratogenic, and primaquine poses a significant risk of fetal intravascular hemolysis in G6PD-deficient fetuses.⁵ Other drugs, such as atovaquone/proguanil and artesunate, are not well studied in pregnancy, and therefore are not recommended for use unless other options are not available.^2,6

Among drugs that are well studied and without known direct fetal-damaging effects, adverse drug reaction profiles can guide use based on disease prevalence and drug-resistance patterns.

• Chloroquine is widely used because it is inexpensive and well tolerated, with only pruritus, mouth ulcers, and gastrointestinal upset as the most common adverse effects.
• Mefloquine is usually well tolerated, but can cause dose-related neuropsychiatric effects; it is contraindicated in those with a history of epilepsy or psychiatric disease.
• Sulfadoxine and pyrimethamine are not normally used as prophylaxis for any patient, due to the risk of toxic epidermal necrolysis and Stevens-Johnson syndrome, and the possible risk of jaundice and kernicterus if used in the third trimester of pregnancy.
• Quinine, which can be used for treatment or prophylaxis, may cause hypoglycemia, an effect that is more pronounced during pregnancy and requires close monitoring of blood glucose levels.^5,7

Given these reaction profiles, chloroquine or mefloquine are usually the best choice with their superior safety and efficacy.

Figure
Best protection: Avoidance

Recommendations from others

The World Health Organization (WHO) recommends pregnant women avoid travel to malarial regions. If travel is required, WHO recommends chloroquine as first-line prophylaxis in pregnancy (plus proguanil if the region exhibits emerging chloroquine resistance). In areas with proven chloroquine resistance, mefloquine is the drug of choice. Other antimalarials—such as quinine, pyrimethamine, sulfadoxine, and artesunate—should not be withheld if the preferred drugs are not available, or if the infection is life-threatening.²

The Centers for Disease Control and Prevention (CDC) also recommends avoiding travel to malaria-endemic regions during pregnancy, but if travel is necessary, the CDC advises use of chloroquine (or mefloquine in regions with chloroquine resistance). The CDC discourages the use of atovaquone/proguanil, doxycycline, and primaquine, due to known adverse fetal effects or inadequate experience in pregnancy.⁶

Acknowledgments

The opinions and assertions contained herein are the private views of the authors and not to be construed as official, or as reflecting the views of the US Air Force Medical Service or the US Air Force at large.

Evidence summary

With the rise in international travel and adventure sports, individuals are at increased risk of acquiring infections by drinking water from impure water sources. Common waterborne infections that back-country and international travelers may contract include bacterial diarrhea, viruses, protozoa (such as Giardia and Cryptosporidium), and parasites (such as schistosoma). The risk of infection varies based on travel location.

To prevent illness, travelers may seek medical guidance regarding safe water practice. In one study, 36% of travelers sought advice from a physician prior to international travel.² Preventing waterborne infections should be a component of traveler education, in addition to other standard advice, such as mosquito avoidance and immunizations.³ (For more on travel safety, see these Clinical Inquiries: “When should travelers begin malaria prophylaxis?” in the November 2007 Journal of Family Practice, pages 950–952, and “What is the most effective and safe malaria prophylaxis during pregnancy?” on page 51 of this issue.)

Which devices meet EPA standards?

The EPA has established a “minimal microbiological hazard” allowed for a portable water purification system to be considered safe. Water purifiers must reduce bacteria by 99.9999%, viruses by 99.99%, and protozoa (such as Cryptosporidium parvum) by 99.9% to receive an EPA certification number.⁴

There are no head-to-head trials comparing the effectiveness of different methods of purification to prevent infectious disease. The majority of the evidence is based on data provided by manufacturers to the EPA, with some independent studies and expert opinion (TABLE).

Expert opinion recommends bringing water to a rapid boil for at least 3 minutes and letting it cool as an effective means of water purification.⁵ Chlorine dioxide tablets, the MIOX purifier, and UV light (SteriPEN) have all met EPA standards for lower pathogen counts under ideal conditions. Halogenation does not reduce Cryptosporidium below the microbiological hazard of 99.9%, but it is generally accepted to effectively treat viruses, bacteria, and other protozoa after filtering through a cloth to remove large particles.⁶

Filtration with an absolute pore size of <0.1 micrometer (10 times smaller than the EPA standard) has been generally accepted as effective against protozoa and bacteria, but it is not effective against viruses because of their small size.⁷ When combined with either halogenation or charcoal filters, filtration can be effective against all pathogens.⁸

TABLE
Portable water purification: How do these 6 methods compare?

METHOD	EFFECTIVENESS	ADVANTAGES	DISADVANTAGES
Boiling with cooling*	Kills viruses, bacteria, protozoa, and parasites	simple, universally accepted, no special equipment required	Time-consuming, may require large amounts of fuel
chlorine dioxide*	Kills bacteria, viruses, protozoa, and parasites	same as chlorine/iodine treatment but also treats Cryptosporidium, good palatability	Must wait up to 4 hours to treat Cryptosporidium, costs more than iodine/chlorine ($13 for 30 tabs)
Chlorine/iodine	Kills bacteria, viruses, protozoa (not Cryptosporidium), and parasites	Inexpensive, easy, lightweight, treats large quantities	Does not kill Cryptosporidium, poor taste, must wait for water to be treated; contraindicated in pregnancy, thyroid disease; not recommended beyond few weeks of use
Filtration †	Removes parasites, Giardia, Cryptosporidium, and bacteria	Able to use water immediately, removes sediment, many have combination of activated carbon, chemical disinfectant, or both	Can potentially be expensive, filters may clog easily, heavy, not effective against small particle viruses, therefore should supplement with chlorine or iodine
MIOX Purifier*	Kills bacteria, viruses, protozoa, and parasites	light (8 oz), sturdy, treats large quantities; requires camera batteries and salt	Cost $130, must wait for 4 hours and treat with higher strength to treat Cryptosporidium; requires 30 minutes to treat viruses, bacteria, and Giardia
UV light (steriPEN) ‡	Kills bacteria, viruses, protozoa, parasites in clear water	Light (8 oz), quick (treats 16 oz of water in 1 minute)	Cost $100, does not work in turbid conditions
* Meets EPA standards.
† some filtration systems meet EPA standards. See chppm-www.apgea.army.mil/WPD/CompareDevices.aspx for testing results of individual filters.1
‡ Meets EPA standards in clear water.

Recommendations from others

The US Army Center for Health Promotion and Preventive Medicine (USACHPPM) published a report in 2006 on the efficacy of commercial off-the-shelf individual water purifiers.⁸ Using National Sanitation Foundation Protocol P248 and applying it to “real-world” emergency military operational conditions, USACHPPM found that no device scored high on every attribute, and that overall scores for most devices were in the moderate range. The top score for any device was 79 (out of 100).⁸

The overall top 3 scoring products were: 1) the SweetWater Purifier from Mountain Safety Research; 2) the Micropur MP 1 tablets from Katadyn North America, Inc; and 3) the First Need Deluxe water purifier from General Ecology, Inc.

Acknowledgments

The opinions and assertions contained herein are the private views of the authors and not to be construed as official, or as reflecting the views of the US Air Force Medical Service or the US air Force at large.

Evidence summary

With the rise in international travel and adventure sports, individuals are at increased risk of acquiring infections by drinking water from impure water sources. Common waterborne infections that back-country and international travelers may contract include bacterial diarrhea, viruses, protozoa (such as Giardia and Cryptosporidium), and parasites (such as schistosoma). The risk of infection varies based on travel location.

To prevent illness, travelers may seek medical guidance regarding safe water practice. In one study, 36% of travelers sought advice from a physician prior to international travel.² Preventing waterborne infections should be a component of traveler education, in addition to other standard advice, such as mosquito avoidance and immunizations.³ (For more on travel safety, see these Clinical Inquiries: “When should travelers begin malaria prophylaxis?” in the November 2007 Journal of Family Practice, pages 950–952, and “What is the most effective and safe malaria prophylaxis during pregnancy?” on page 51 of this issue.)

Which devices meet EPA standards?

The EPA has established a “minimal microbiological hazard” allowed for a portable water purification system to be considered safe. Water purifiers must reduce bacteria by 99.9999%, viruses by 99.99%, and protozoa (such as Cryptosporidium parvum) by 99.9% to receive an EPA certification number.⁴

There are no head-to-head trials comparing the effectiveness of different methods of purification to prevent infectious disease. The majority of the evidence is based on data provided by manufacturers to the EPA, with some independent studies and expert opinion (TABLE).

Expert opinion recommends bringing water to a rapid boil for at least 3 minutes and letting it cool as an effective means of water purification.⁵ Chlorine dioxide tablets, the MIOX purifier, and UV light (SteriPEN) have all met EPA standards for lower pathogen counts under ideal conditions. Halogenation does not reduce Cryptosporidium below the microbiological hazard of 99.9%, but it is generally accepted to effectively treat viruses, bacteria, and other protozoa after filtering through a cloth to remove large particles.⁶

Filtration with an absolute pore size of <0.1 micrometer (10 times smaller than the EPA standard) has been generally accepted as effective against protozoa and bacteria, but it is not effective against viruses because of their small size.⁷ When combined with either halogenation or charcoal filters, filtration can be effective against all pathogens.⁸

TABLE
Portable water purification: How do these 6 methods compare?

METHOD	EFFECTIVENESS	ADVANTAGES	DISADVANTAGES
Boiling with cooling*	Kills viruses, bacteria, protozoa, and parasites	simple, universally accepted, no special equipment required	Time-consuming, may require large amounts of fuel
chlorine dioxide*	Kills bacteria, viruses, protozoa, and parasites	same as chlorine/iodine treatment but also treats Cryptosporidium, good palatability	Must wait up to 4 hours to treat Cryptosporidium, costs more than iodine/chlorine ($13 for 30 tabs)
Chlorine/iodine	Kills bacteria, viruses, protozoa (not Cryptosporidium), and parasites	Inexpensive, easy, lightweight, treats large quantities	Does not kill Cryptosporidium, poor taste, must wait for water to be treated; contraindicated in pregnancy, thyroid disease; not recommended beyond few weeks of use
Filtration †	Removes parasites, Giardia, Cryptosporidium, and bacteria	Able to use water immediately, removes sediment, many have combination of activated carbon, chemical disinfectant, or both	Can potentially be expensive, filters may clog easily, heavy, not effective against small particle viruses, therefore should supplement with chlorine or iodine
MIOX Purifier*	Kills bacteria, viruses, protozoa, and parasites	light (8 oz), sturdy, treats large quantities; requires camera batteries and salt	Cost $130, must wait for 4 hours and treat with higher strength to treat Cryptosporidium; requires 30 minutes to treat viruses, bacteria, and Giardia
UV light (steriPEN) ‡	Kills bacteria, viruses, protozoa, parasites in clear water	Light (8 oz), quick (treats 16 oz of water in 1 minute)	Cost $100, does not work in turbid conditions
* Meets EPA standards.
† some filtration systems meet EPA standards. See chppm-www.apgea.army.mil/WPD/CompareDevices.aspx for testing results of individual filters.1
‡ Meets EPA standards in clear water.

Recommendations from others

The US Army Center for Health Promotion and Preventive Medicine (USACHPPM) published a report in 2006 on the efficacy of commercial off-the-shelf individual water purifiers.⁸ Using National Sanitation Foundation Protocol P248 and applying it to “real-world” emergency military operational conditions, USACHPPM found that no device scored high on every attribute, and that overall scores for most devices were in the moderate range. The top score for any device was 79 (out of 100).⁸

The overall top 3 scoring products were: 1) the SweetWater Purifier from Mountain Safety Research; 2) the Micropur MP 1 tablets from Katadyn North America, Inc; and 3) the First Need Deluxe water purifier from General Ecology, Inc.

Acknowledgments

The opinions and assertions contained herein are the private views of the authors and not to be construed as official, or as reflecting the views of the US Air Force Medical Service or the US air Force at large.

Evidence summary

With the rise in international travel and adventure sports, individuals are at increased risk of acquiring infections by drinking water from impure water sources. Common waterborne infections that back-country and international travelers may contract include bacterial diarrhea, viruses, protozoa (such as Giardia and Cryptosporidium), and parasites (such as schistosoma). The risk of infection varies based on travel location.

To prevent illness, travelers may seek medical guidance regarding safe water practice. In one study, 36% of travelers sought advice from a physician prior to international travel.² Preventing waterborne infections should be a component of traveler education, in addition to other standard advice, such as mosquito avoidance and immunizations.³ (For more on travel safety, see these Clinical Inquiries: “When should travelers begin malaria prophylaxis?” in the November 2007 Journal of Family Practice, pages 950–952, and “What is the most effective and safe malaria prophylaxis during pregnancy?” on page 51 of this issue.)

Which devices meet EPA standards?

The EPA has established a “minimal microbiological hazard” allowed for a portable water purification system to be considered safe. Water purifiers must reduce bacteria by 99.9999%, viruses by 99.99%, and protozoa (such as Cryptosporidium parvum) by 99.9% to receive an EPA certification number.⁴

There are no head-to-head trials comparing the effectiveness of different methods of purification to prevent infectious disease. The majority of the evidence is based on data provided by manufacturers to the EPA, with some independent studies and expert opinion (TABLE).

Expert opinion recommends bringing water to a rapid boil for at least 3 minutes and letting it cool as an effective means of water purification.⁵ Chlorine dioxide tablets, the MIOX purifier, and UV light (SteriPEN) have all met EPA standards for lower pathogen counts under ideal conditions. Halogenation does not reduce Cryptosporidium below the microbiological hazard of 99.9%, but it is generally accepted to effectively treat viruses, bacteria, and other protozoa after filtering through a cloth to remove large particles.⁶

Filtration with an absolute pore size of <0.1 micrometer (10 times smaller than the EPA standard) has been generally accepted as effective against protozoa and bacteria, but it is not effective against viruses because of their small size.⁷ When combined with either halogenation or charcoal filters, filtration can be effective against all pathogens.⁸

TABLE
Portable water purification: How do these 6 methods compare?

METHOD	EFFECTIVENESS	ADVANTAGES	DISADVANTAGES
Boiling with cooling*	Kills viruses, bacteria, protozoa, and parasites	simple, universally accepted, no special equipment required	Time-consuming, may require large amounts of fuel
chlorine dioxide*	Kills bacteria, viruses, protozoa, and parasites	same as chlorine/iodine treatment but also treats Cryptosporidium, good palatability	Must wait up to 4 hours to treat Cryptosporidium, costs more than iodine/chlorine ($13 for 30 tabs)
Chlorine/iodine	Kills bacteria, viruses, protozoa (not Cryptosporidium), and parasites	Inexpensive, easy, lightweight, treats large quantities	Does not kill Cryptosporidium, poor taste, must wait for water to be treated; contraindicated in pregnancy, thyroid disease; not recommended beyond few weeks of use
Filtration †	Removes parasites, Giardia, Cryptosporidium, and bacteria	Able to use water immediately, removes sediment, many have combination of activated carbon, chemical disinfectant, or both	Can potentially be expensive, filters may clog easily, heavy, not effective against small particle viruses, therefore should supplement with chlorine or iodine
MIOX Purifier*	Kills bacteria, viruses, protozoa, and parasites	light (8 oz), sturdy, treats large quantities; requires camera batteries and salt	Cost $130, must wait for 4 hours and treat with higher strength to treat Cryptosporidium; requires 30 minutes to treat viruses, bacteria, and Giardia
UV light (steriPEN) ‡	Kills bacteria, viruses, protozoa, parasites in clear water	Light (8 oz), quick (treats 16 oz of water in 1 minute)	Cost $100, does not work in turbid conditions
* Meets EPA standards.
† some filtration systems meet EPA standards. See chppm-www.apgea.army.mil/WPD/CompareDevices.aspx for testing results of individual filters.1
‡ Meets EPA standards in clear water.

Recommendations from others

The US Army Center for Health Promotion and Preventive Medicine (USACHPPM) published a report in 2006 on the efficacy of commercial off-the-shelf individual water purifiers.⁸ Using National Sanitation Foundation Protocol P248 and applying it to “real-world” emergency military operational conditions, USACHPPM found that no device scored high on every attribute, and that overall scores for most devices were in the moderate range. The top score for any device was 79 (out of 100).⁸

The overall top 3 scoring products were: 1) the SweetWater Purifier from Mountain Safety Research; 2) the Micropur MP 1 tablets from Katadyn North America, Inc; and 3) the First Need Deluxe water purifier from General Ecology, Inc.

Acknowledgments

The opinions and assertions contained herein are the private views of the authors and not to be construed as official, or as reflecting the views of the US Air Force Medical Service or the US air Force at large.