Tropical Medicine and International Health
Combining Drinking Water Treatment and Hand Washing for Diarrhoea Prevention, a Cluster Randomised Controlled Trial
In previous studies, both hand washing with soap and point-of-use treatment of drinking water have been shown to decrease the frequency of childhood diarrhea. Currently, there are no data showing that combining the two methods would further decrease the frequency of diarrhea in developing areas.
This cluster, randomized, controlled trial was completed in a total of 1340 households in 47 clusters of squatter settlements in Pakistan from April to December 2003. The 47 clusters were randomized to 5 study groups: 1) Bleach water treatment, 2) Hand washing promotion with soap, 3) Flocculent-disinfectant water treatment, 4) Flocculent-disinfectant plus hand washing promotion, and 5) Control. Field workers arranged neighborhood meetings with educational materials, provided appropriate materials to each cluster (bleach, flocculent-disinfectant, and/or soap, or simply educational materials), and then visited each household twice weekly throughout the study period. Each participant family underwent a baseline study as well as weekly questioning about diarrhea in the mother and children within the family. The primary study outcome was the percent of person-weeks that study subjects suffered at least 1 day of diarrhea.
Study subjects with any intervention had markedly less diarrhea than the control subjects (55%). The reduction in diarrhea ranged from 51% in those subjects receiving soap and hand washing precautions to 64% in those subjects receiving flocculent-disinfectant. The largest reduction in diarrhea came in children ages 5 to 15 years old, although there was a non– statistically significant reduction in infants and young children as well. However, the data showed no improvement in diarrhea reduction by combining hand washing and water disinfection when compared to a single method alone.
The authors had several theories why two methods of diarrhea prevention did not have an additive effect. Primarily, the premise is that most diarrhea is caused by a certain threshold number of pathogens, and when the level drops below that threshold via one mechanism, diarrhea is less likely to occur. Another theory is that the introduction of one form of improved hygiene might have improved the other without more formal teaching in place. Until large-scale water treatment is in place, public health organizations will have to continue teaching means of diarrhea prevention. Although these authors did not find an additive effect of combining the two mechanisms, their final recommendation is that both mechanisms be taught in the hopes that at least one will be adopted into educated households.
(Trop Med Int Health. 2006;11:479–489) SP Luby, M Agboatwalla, J Painter, et al.Prepared by Karen Nolan Kuehl, MD, FACEP Oregon Health & Science University, Portland, OR, USA
Archives of Disease in Childhood
Solar Disinfection of Water for Diarrhoeal Prevention in Southern India
Impure drinking water contributes to disease in millions of children worldwide. Costs of purification, lack of materials, and compliance concerns pose barriers to rectifying this problem. While experimental lab protocols have demonstrated the efficacy of solar irradiation in disinfecting water, there have been few field trials examining the effectiveness of this method.
This study used a prospective cohort study design in which 100 children under 5 years were selected as cases and 100 children as controls. All households received education on diarrhea prevention and oral rehydration. The intervention households were given 12 locally sold, 1-liter, plastic (polyethylene terephthalate) bottles and were instructed in their proper use for solar disinfection. Compliance was assessed by proper use of bottles as observed during weekly home visits by field workers.
After 6 months of follow-up, the incidence of diarrhea in the intervention group was 1.7 per child-year and 2.7 among controls. Additionally, the mean duration of each diarrheal episode was 2.1 days in the intervention group and 3.6 days in the controls. The mean number of stools per diarrheal episode was significantly different between the two groups with 4.0 in the solar disinfection group and 7.8 in the controls. Significantly, severe diarrhea, defined as requiring intravenous rehydration, was 13.9% in the intervention group while it was 34.1% in the controls (χ2 = 3.68, P = .05). Calculated as incidence, severe diarrhea occurred at a rate of 0.6 per child-year among the intervention children and at 1.3 per child-year in controls. There was no significant trend in diarrhea incidence over the 6-month follow-up in either the cases or controls.
The acceptability evaluations via focus groups and interviews showed that the women in the intervention group thought the solar method was easy and affordable compared to boiling, which was too expensive for most families in this study. Disadvantages were too few bottles, and the tendency for bottles to become cracked or opaque (they were replaced if broken). Eighty-eight percent of the intervention families responded to questionnaires, with 86% of those reporting that the children sometimes drank water other than solar-disinfected water. Self-reported use of the method was 20% of families reporting daily use and 50% of families reporting use over 80% of the days. Six families reported not using the intervention at least half of the days.
This intervention has potential in terms of sustainability given that it is cheap and generally acceptable, but this must be further evaluated as the weekly follow-up may have influenced the compliance and efficacy of the study. Solar disinfection is not a total solution, however, as demonstrated by the fact that over 50% of the children did experience an episode of diarrhea in the study period. While this study assists in our understanding of what works in purifying water on the community level, the long-term solution may depend on both economic and political factors beyond the scope of this study.
(Arch Dis Child. 2006;91:139–141) A Rose, S Roy, V Abraham, et al.Prepared by Alex Foster, MS3Oregon Health & Science University, Portland, OR, USA
New England Journal of Medicine
Postexposure Treatment with Doxycycline for the Prevention of Tick-Borne Relapsing Fever
Tick-borne relapsing fever (TBRF) is a febrile illness characterized by high fever, headaches, dizziness, and myalgias. Fever recurs and resolves many times over the course of the illness when untreated. The causative organism, Borrelia persica, is carried by the Ornithodoros tholozani tick, with transmission of infection occurring up to 50% of the time after a tick bite. Diagnosis of the disease occurs after direct visualization of the organism in a blood smear, typically collected during a febrile episode. Polymerase chain reaction (PCR) is also used. Treatment is commonly with doxycycline, which has been shown to be an effective postexposure treatment in other spirochetal infections such as Lyme disease. These authors designed a controlled trial to study the safety and efficacy of postexposure treatment to specifically prevent TBRF.
In this double-blind, placebo-controlled trial, 93 subjects with either known tick bite or close exposure to a person with known tick bite were randomly assigned to receive either doxycycline for 5 days or placebo. Subjects were recruited from the Israeli military and had spent the preceding 5 days in caves and niches in an area endemic for TBRF. Those included in the study were subjects examined for evidence of tick bite (central erythematous area surrounded by bluish-purplish area) or were the direct partners of those bitten by ticks. All subjects underwent extensive questioning about prior episodes of TBRF as well as any current potential exposures and methods of prevention. Each subject was then monitored closely for 3 weeks for symptoms of TBRF as well as possible side effects of the medication. Blood samples were collected for smear, PCR, and serologic analysis at the beginning and end of the study period, as well as if subjects developed any fever, headache, or malaise. Subjects with fever and positive blood smear were diagnosed with TBRF.
Of the 93 included subjects, 52 had signs of tick bites and 41 were close contacts. Ten subjects, all in the placebo group, developed fever and a positive blood smear. No subjects in the treated group developed TBRF, which showed a significant difference (P < .001) with the prophylaxis treatment and an efficacy rate of 100%. Incubation period ranged from 5 to 10 days, and all diagnosed subjects were treated with doxycycline effectively. There was no significant difference between the treated and placebo groups in terms of side effects.
This study proved the efficacy of providing postexposure prophylaxis for 5 days with doxycycline in a population with high risk of exposure to B persica. Although there would undoubtedly be more side effects if a larger population were treated with the medication, the benefits of postexposure prophylaxis for those with known or possible tick exposures in endemic areas are clearly seen in this well-done study. Education of patients traveling to endemic regions should include identification and prevention of tick bites, and medical kits should include doxycycline for appropriate patients.
(N Engl J Med. 2006;355:148–155) T Hasin, N Davidovitch, R Cohen, et al. Prepared by Karen Nolan Kuehl, MD, FACEP Oregon Health & Science University, Portland, OR, USA
The American Journal of Sports Medicine
The Relationship Between Menstrual Cycle Phase and Anterior Cruciate Ligament Injury: A Case-Control Study of Recreational Alpine Skiers
According to National Collegiate Athletic Association statistics, as well as other sources listed in this study, women are more likely to sustain anterior cruciate ligament (ACL) tears than men, when competing in common sports. Interestingly, there have been previous studies completed on the effects of phases of the menstrual cycle on the risk of ACL tear, but these have not included a control group. These authors designed a case-control study that used levels of serum estrogen and progesterone at the time of injury to help determine any increased risk of ACL injury at one particular part of the menstrual cycle.
The case-control study was completed at a New England ski resort clinic affiliated with the publishing university (University of Vermont). Female patients were enrolled after sustaining an ACL injury, which was determined by clinical examination findings. An uninjured female control was enrolled for each injured patient. All enrolled subjects completed questionnaires about skiing history, injury history, and menstruation history. Each subject provided a blood sample for analysis of estradiol and progesterone concentrations. Although estradiol is present in both preovulatory and postovulatory phases, progesterone is only present in the postovulatory phase, when ovulation has occurred. Patients were assigned into a preovulatory or postovulatory group, depending on their hormone levels as well as correlation with their self-reported menstrual cycles.
Of 170 women with clinically evident ACL tears that presented to the ski clinic during the study period (2000–2004), 46 agreed to participate in the study and were matched with 45 female controls. Controls were similar to test subjects, except in two important variables: subjects in the control group had more experience skiing (P = .01) and were better skiers (P = .002) than the test group. When using blood levels of progesterone for analysis, females in the preovulatory phase of their menstrual cycle were more likely to tear their ACL than those in the postovulatory phase (P = .027). However, when the data were adjusted for skiing ability and experience, and the laboratory data were corroborated with self-reported menstrual cycle data, the difference was not significant (P = .086).
This study attempts to establish a hormonal relationship to the already known increased risk of ACL injuries in women. As noted in their paper, the authors’ hypothesis is driven by prior clinical and laboratory data. Despite the addition of controls, this study does not provide any additional information towards answering the question because of marginal study design. Case-control studies are much less expensive and labor intensive, but researchers must make a reasonable effort to match cases and controls. The study controls had significantly more skiing ability and had skied 50% more seasons than study subjects. They were also a median 5 years younger, and weighed a mean 3.5 kg less than the injured skiers. The presumed multiple factors leading to an ACL injury will require better study design to elucidate the components.
(Am J Sports Med. 2006;34:757–764) BD Beynnon, RJ Johnson, S Braun, et al. Prepared by Damon Kuehl, MD, and Karen Kuehl, MD, FACEPOregon Health & Science University, Portland, OR, USA
Annals of Internal Medicine
Both Tadalafil and Dexamethasone May Reduce the Incidence of High-Altitude Pulmonary Edema
High-altitude pulmonary edema (HAPE) is thought to be caused by a combination of exaggerated hypoxic pulmonary vasoconstriction leading to elevated pulmonary capillary pressures as well as impaired resorption of alveolar fluid and decreased availability of nitric oxide in the lungs. Acute mountain sickness (AMS) is a more generalized constellation of symptoms including headache, anorexia, dizziness, nausea, and insomnia, and may or may not precede HAPE. Acetazolamide and dexamethasone have been shown to prevent AMS and nifedipine has been shown to prevent HAPE, according to citations mentioned in this article. Recently, a new focus of using phosphodiesterase-5 inhibitors such as tadalafil has been used to restore the impaired effects of nitric oxide in persons susceptible to HAPE (at least one case in the past). This study was designed to study the effects of tadalafil and dexamethasone on the incidence of HAPE, as well as AMS, in adults previously diagnosed with HAPE.
In this double-blinded trial, 29 adults (25 men and 4 women), all with a history of HAPE, were randomly assigned to receive prophylactic tadalafil, dexamethasone, or placebo during a 24-hour ascent and then 2-day stay at 4559 meters. Baseline measurements had been completed on each participant approximately 3 weeks prior to the study. While at altitude, each subject used the Lake Louise scoring protocol to assess for AMS, and was assessed clinically for HAPE: dry cough, orthopnea, or pulmonary rales. Any clinical suspicion of HAPE led to a portable chest radiograph. Any participants with positive diagnoses of AMS or HAPE were removed from the study, and treated appropriately (AMS = oxygen, dexamethasone, HAPE = oxygen, nifedipine). In addition, each participant underwent Doppler echocardiography to measure systolic pulmonary artery pressure. The investigators admit that their power was inadequate with their small study size.
Immediately upon arrival at 4559 meters, 2 subjects in the tadalafil arm developed AMS by Lake Louise criteria and were removed from the study. HAPE developed in 7/9 subjects on placebo, 1/8 subjects on tadalafil, and 0/10 subjects on dexamethasone (P = .007 for tadalafil vs placebo; P < .001 for dexamethasone vs placebo). AMS developed in 8/9 subjects on placebo, 7/10 subjects on tadalafil, and 3/10 receiving dexamethasone (P = 1.0 for tadalafil vs placebo; P = .020 for dexamethasone vs placebo). Pulmonary artery pressures increased less in those receiving dexamethasone (P = .005) and tadalafil (P = .012) compared to placebo.
The results suggest that dexamethasone and tadalafil decrease systolic pulmonary artery pressure at altitude, and are both effective in preventing HAPE in those with a history of HAPE. Interestingly, this study also showed dexamethasone to be effective in preventing AMS. Dexamethasone, though shown in past studies to treat HAPE, is now suggested as a preventative medication. The prolonged intake of the steroid might upregulate gene expression, thereby preventing endothelial dysfunction in pulmonary arteries and increasing necessary nitric oxide. Tadalafil also prevented HAPE in this small study, but might have increased susceptibility to AMS in 2 individuals. These authors go farther and state “although acetazolamide therapy is the standard of care for prevention of AMS, dexamethasone may be the ideal prophylaxis to reduce the risk for HAPE and AMS in HAPE-susceptible persons who must ascend rapidly to high altitude.” Dexamethasone should not, however, become a pharmaceutical substitute for appropriate acclimatization methods in mountaineers.
(Ann Intern Med. 2006;145:497–506) M Maggiorini, HP Brunner-La Rocca, S Peth, et al. Prepared by Karen Nolan Kuehl, MD, FACEPOregon Health & Science University, Portland, OR, USA
American Journal of Emergency Medicine
Patient Transport Via Private Vehicle in Sequoia and Kings Canyon National Parks
Emergency medical service (EMS) providers are frequently called upon to assist and transport stable patients with medical problems triaged as “low-acuity.” These patients are at low risk for developing severe complications and rarely require stabilization or pain control offered by EMS providers. Although the overall utilization of EMS transports by the general public has increased, only a small number of systems have implemented a system that allows for alternative transport for patients with minor complaints. One possible strategy has been suggested to alleviate this problem: privately owned vehicle (POV) transport. In additional to legal and medical concerns, this system in a wilderness setting faces additional obstacles: long transport times to hospitals, inadequate training of triage personnel, and lack of resources for EMS personnel. This study attempts to investigate the feasibility of POV transportation with online physician medical control in the Sequoia and Kings Canyon National Parks.
This was a prospective, observational analysis of POV transport during a 1-year period. The study population was drawn from 381 patient encounters, of which 113 (30%) were chosen for POV transport. Fifty (44%) of these patients were successfully contacted and enrolled in the study. The participants were asked 8 survey questions regarding their POV transport experience. Additionally, medical records were reviewed for any patient admitted to the hospital to ensure review of all park POV transports.
Forty-two of the 50 patients contacted (84%) were advised to see a physician, 2 (4%) were not advised, and 6 (12%) could not remember. A review of the run sheet of the 8 patients who were not advised or could not remember found that all patients stated their intent to go by POV for further medical care. Thirty of the 42 patients (71%) presented to hospitals for evaluation, suggesting they could remember and follow disposition instructions. Forty-three of the 50 (86%) patients stated they were “all better,” while 7 (14%) of the patients were “somewhat better.” None of the patients believed that their condition worsened. Fourteen of the 30 patients (47%) who went to the hospital reported pain at a level greater than 5 on a scale of 1 to 10. Of these 14 patients, only 4 (29%) stated they would have been willing to pay for EMS transport. Contrastingly, 8 of the 16 (50%) who rated their pain 5 or less reported they would have been willing to pay. Five patients stated their pain became much worse during POV transport but only 1 of the 5 (20%) stated they would have wanted EMS transport if they had to pay for it.
The authors concluded that POV transport in the wilderness setting, with 100% online physician medical control, was not associated with any detectable adverse outcomes and can be utilized in carefully selected cases. In their study, the investigators were able to answer yes to the following questions: 1) Are patients able to remember and follow instructions that they are given?; 2) Can patient expectations be fulfilled by POV transport?; and 3) Is POV transport with 100% online physician medical control safe? More research is necessary before a full-scale system can be implemented, and, obviously, this system could only be used with appropriately selected patients.
(Am J Emerg Med. 2005;23:311–315) A Sae, S Haverly, J Uller, M Shalit, and G Stroh. Prepared by Henry Truong, MS3Oregon Health & Science University, Portland, OR, USA