Knowledge and attitudes of hospital-based physicians and trainees about HIV infection in the United States, Canada, India, and Thailand.

OBJECTIVE: To examine the attitudes and knowledge of health care professionals regarding human immunodeficiency virus (HIV) infection in countries with a varying prevalence of HIV infection to assist in the development of acquired immunodeficiency syndrome (AIDS) educational programs. DESIGN: Anonymous questionnaire with four sections: demographics, attitudes, knowledge, and an open-ended question investigating feelings about the potential impact that HIV infection may have on respondents' practices. PARTICIPANTS: Final-year medical students, house staff, and attending physicians at teaching hospitals in India, Thailand, Canada, and the United States. RESULTS: From January to October 1992, 819 health care professionals completed the questionnaire: 340 from India, 196 from Canada, 155 from the United States, and 128 from Thailand. The percentage of respondents who had previous contact with patients with HIV/AIDS varied from 30% to 98%; it was lowest in India, followed by Thailand and then Canada, and highest in the United States. Percentages of respondents uncomfortable performing a physical examination on a patient with HIV/AIDS were 24%, 25%, 9%, and 4%, respectively. Mean HIV/AIDS knowledge scores were 83%, 84%, 92%, and 93%, respectively. Most respondents correctly identified modes of transmission of HIV infection. Only 67% of Indian health care professionals understood the concept of a false-negative screening serologic test, compared with 98% of Canadian health care professionals. In Canada and the United States, only 78% and 76%, respectively, understood the concept of a false-positive screening serologic test. Awareness of an asymptomatic stage of HIV infection ranged from 32% in India to 74% in Canada. Despite their concerns of becoming infected, health care professionals in countries with a lower prevalence of HIV infection reported a strong ethical duty to care for these patients. CONCLUSIONS: Level of comfort in caring for HIV-infected patients and HIV/AIDS knowledge scores varied directly with the amount of previous contact with these patients. Disturbing numbers of health care professionals from all four countries did not understand the potential problems of the enzyme-linked immunosorbent assay serologic test and a significant percentage were unaware of the asymptomatic stage of HIV infection. There is a universal need for increased education of health care professionals about HIV infection and AIDS.

Prevention of malaria.

With the increased spread of chloroquine-resistant Plasmodium falciparum malaria and mounting evidence of lack of efficacy and toxicity of alternative drugs, it has become extremely difficult to propose simple, widely applicable and uniformly acceptable recommendations for malaria chemoprophylaxis. With regard to specific drugs, it is clear that because of its toxicity amodiaquine should no longer be used for chemoprophylaxis, and that pyrimethamine/sulfadoxine should, for the most part, be used only as a presumptive therapy. The pyrimethamine/dapsone combination is promising, but data on its efficacy are limited. Although proguanil (chloroguanide) is recommended by several sources because of its safety, disturbing reports of chemoprophylaxis failure in Africa and a well-documented lack of efficacy in South East Asia would suggest that its usefulness may be limited. However, a recent study has documented the efficacy of a proguanil-sulphonamide combination in Thailand, an area of high grade chloroquine resistance. Although long term studies of drug safety are not yet available, doxycycline and mefloquine appear to be the drugs of choice in areas where P. falciparum shows multidrug resistance. Regardless of the drug regimen recommended for chemoprophylaxis, travellers must be informed that no present-day antimalarial agent guarantees protection against malaria.

Treatment of malaria--1990.

Malaria has become an increasingly common health problem in the 1970s and 1980s, both in areas where infection is endemic and in travellers returning to non-endemic areas. The severity of infection varies widely, depending on the plasmodial species involved, and there is an extensive chemotherapeutic armamentarium currently available to combat malarial infection. Drug chemistry, pharmacokinetics, mechanism of drug action and resistance, and toxicities are outlined for the cinchona alkaloids (quinine and quinidine), chloroquine, amodiaquine, pyrimethamine, the sulphonamides, pyrimethamine/sulfadoxine, mefloquine, pyrimethamine/sulfadoxine/mefloquine, the sesquiterpene lactones, primaquine, and other drugs. A knowledge of the distribution of drug resistance is vital for the provision of effective antimalarial therapy, and current information in this area is outlined. Chloroquine remains the mainstay of treatment for the erythrocytic stages of Plasmodium vivax, P. ovale, P. malariae, and chloroquine-sensitive P. falciparum malaria. The dormant hepatic stages of P. vivax and P. ovale also require further treatment with primaquine. Quinine, alone or in combination with other drugs, is the primary agent used to treat chloroquine-resistant falciparum malaria. Falciparum infection can rapidly become fatal, therefore its complications of multiple organ failure, heavy parasitaemias, cerebral malaria, and hypoglycaemia must be recognised and managed promptly. Because these protozoal parasitic infections are now encountered throughout the world and can become life-threatening, a wide variety of practitioners must become more familiar with their correct treatment.

Prevention of traveler's diarrhea.

Preventing traveler's diarrhea is usually a matter of common sense, good luck, and the host's ability to defend against enteric pathogens, particularly enterotoxigenic Escherichia coli. Untreated tap water, ice cubes, unpasteurized milk products, salads, food from street vendors, and dining in unhygienic-appearing restaurants should be avoided. Well-cooked food that is served hot and carbonated, commercially bottled beverages are usually safe. Food and water precautions, however, are no guarantee of success in preventing traveler's diarrhea. Bismuth subsalicylate used prophylactically is somewhat inconvenient and is only moderately effective. Although antibiotic prophylaxis is very effective for traveler's diarrhea, particularly the quinolones, it should be reserved for high-risk travelers.

Malaria in travelers. Epidemiology, disease, and prevention.

The combination of increases in international travel and escalating drug resistance has resulted in a growing number of travelers contracting malaria. Preventing malaria-associated morbidity and mortality will require improved health information for travelers about the risk of malaria and appropriate preventive measures, improved recognition of infection by physicians, rapid and accurate laboratory diagnosis, and prompt initiation of effective therapy.

Trematode infections. Opisthorchiasis, clonorchiasis, fascioliasis, and paragonimiasis.

The parasitic diseases of the liver and lung are caused by trematodes or flukes--Opisthorchis viverrini, O. felineus, Fasciola hepatica, and Paragonimus westermani. Humans get infected by eating the second intermediate host of the fluke, for example, fish, crab, or water plant. The disease runs a chronic course. The diagnosis is made by the recover of eggs in stools or sputum, or by serodiagnosis. Praziquantel is the drug of choice except in falcioliaisis.

Seizures and electroencephalograph changes associated with oxamniquine therapy.

A Tanzanian man with a known seizure disorder was admitted to hospital for treatment of schistosomiasis mansoni. He suffered a grand mal seizure soon after the second dose of oxamniquine. This is the first recorded seizured associated with use of this drug. Two other cases are reported in which transient electroencephalograph changes occurred during oxamniquine therapy. The central nervous system effects of oxamniquine are reviewed with respect to its possible epileptogenic effects.

Short report: severe hiccups secondary to doxycycline-induced esophagitis during treatment of malaria.

A 51-year-old man who was treated with quinine and doxycycline for Plasmodium falciparum malaria acquired in West Africa developed hiccups soon after his first dose of antimalarial therapy. Endoscopic examination performed when his hiccups became intractable showed an esophageal erosion and ulcer most likely due to doxycycline. The patient's symptoms resolved on treatment with omeprazole and sucralfate.

Safety and toxicity of oxamniquine in the treatment of Schistosoma mansoni infections, with particular reference to electroencephalographic abnormalities.

Thirty-seven patients infected with Schistosoma mansoni were treated with oxamniquine. All were cured. The only significant adverse reaction was the development of abnormal electroencephalographic (EEG) findings in 6 (17.6%) of 34 patients whose pretreatment EEG was normal. Management of patients, with particular reference to the EEG abnormalities, is discussed.

The role of corticosteroids in the treatment of cerebral schistosomiasis caused by Schistosoma mansoni: case report and discussion.

A 26-year-old Brazilian man was admitted to The Toronto Hospital with a headache and visual scintillation. His last travel to Brazil was five years previously. A computed tomography (CT) scan of the head showed an occipital mass with surrounding vasogenic edema. Occipital brain biopsy revealed Schistosoma mansoni eggs. The patient was treated with two doses of praziquantel (20 mg/kg) and dexamethasone (10 mg). His symptoms and occipital mass resolved. Cerebral schistosomiasis is, in part, caused by the host's inflammatory response to Schistosoma. Modes of treatment have included surgical resection, the antiparasitic drugs oxamniquine or praziquantel, and corticosteroids. Corticosteroids may diminish granulomatous inflammation, thereby preventing further tissue destruction, and there is evidence that they also reduce ova deposition. Our review of the literature supports prompt medical therapy in patients with cerebral schistosomiasis. While the minimally or asymptomatic individual may be treated with praziquantel alone, clinicians should consider adjunctive therapy with corticosteroids for patients with prominent neurologic signs or symptoms or mass lesions with evidence of surrounding edema on a CT scan or by magnetic resonance imaging.

The electrophoretic isoenzyme patterns of strains of Entamoeba histolytica isolated in two major cities in Canada.

The isoenzyme patterns of 92 isolates of Entamoeba histolytica from British Columbia and 28 from Ontario were determined. Seropositivity for E. histolytica was assessed by indirect hemagglutination and enzyme-linked immunosorbent assay in the one center and by ELISA and amebic gel diffusion in the other. In both British Columbia and Ontario nonpathogenic zymodemes I and III were most common. A newly described isoenzyme pattern was identified in Ontario. Only 9 of 120 zymodeme patterns identified were found to be pathogenic strains of E. histolytica. Pathogenic isolates were strongly correlated with clinical symptoms and seropositivity.

Drug sensitivity and isoenzyme type in cloned lines of Plasmodium falciparum.

Clones have been derived by limiting dilution from recent isolates of Plasmodium falciparum from Africa and Brazil. These clones have been characterized for pyrimethamine and chloroquine sensitivity and/or isoenzyme type. Clones obtained from an isolate containing a mixture of GPI isoenzyme types were found to have (with one exception) only GPI-1 or GPI-2. Clones differing 1,000-fold in pyrimethamine resistance were derived from a single isolate from Brazil which was resistant to both pyrimethamine and chloroquine. Several levels of chloroquine sensitivity were observed in the isolates studied. All clones showed levels of chloroquine sensitivity similar to that of their parent isolates. The KZ1 isolate from East Africa had an intermediate level of chloroquine resistance and a flat dose-response curve and each of its clones had a similar dose-response curve, indicating that the intermediate level of chloroquine resistance did not result from the KZ1 isolate's being a mixture of clones with high and low sensitivity.

Effect of malaria chemoprophylaxis on the development of antibodies to Plasmodium falciparum in expatriates living in west Africa.

We studied the relationship between exposure to malaria, the use of long-term chemoprophylaxis with chloroquine, and the prevalence of sporozoite antibodies in 446 expatriates who had lived in 7 West African countries for 6 months-41 years. Filter paper blood samples from 12% of the subjects had antibodies to the repeat region of the Plasmodium falciparum circumsporozoite protein, with a positive correlation between enzyme-linked immunosorbent assay (ELISA) absorbance and years of exposure (r = 0.32, P = less than 0.01). Development of sporozoite antibodies did not correlate with reported use of chloroquine. Ten samples from expatriates with the highest ELISA titers and 10 samples from West African nationals, which were matched for ELISA titer and duration of exposure, were characterized more fully. All 20 samples reacted strongly with sporozoites by immunofluorescence. The 10 samples from nationals reacted strongly with liver-stage antigens by immunofluorescence and with blood-stage antigens by immunofluorescence and immunoblotting. In contrast, the 10 samples from expatriates were negative or only weakly positive in the liver- and blood-stage assays. These results imply that sporozoite antibodies are generally not cross-reactive with blood-stage antigens, and suggest that protective immunity to malaria does not develop during long-term malaria chemoprophylaxis against the erythrocytic stage.

Creeping eruption. A review of clinical presentation and management of 60 cases presenting to a tropical disease unit.

BACKGROUND AND DESIGN: Cutaneous larva migrans is an infection with a larval nematode, most frequently by dog or cat hookworms. It has a characteristic presentation that is easily recognizable. We reviewed the charts of 60 patients with cutaneous larva migrans who presented to the Tropical Disease Unit, Toronto (Ontario) Hospital, during a 6-year period. RESULTS: Ninety-five percent of the patients were Canadians who had recently returned from the tropics or subtropics, notably the Caribbean. Almost all patients had a linear or serpiginous, very pruritic larval track. Topical thiabendazole was efficacious in 52 (98%) of 53 patients treated. Albendazole cured six (88%) of seven patients treated. Because of adverse effects, oral thiabendazole and liquid nitrogen were not utilized. CONCLUSION: We conclude that topical thiabendazole and oral albendazole are very effective and safe modalities for the treatment of cutaneous larva migrans.

Skin problems in returning travelers.

A new skin lesion in a returning traveler often poses a difficult diagnostic problem for the clinician whose knowledge of geographic medicine is limited. To reach a diagnosis the physician has to consider the location and style of travel, exposure to pathogens, length of stay, epidemiology, incubation period, and clinical presentation of dermatologic diseases in the countries visited. As with any dermatologic problem, the appearance of the presenting lesion should help to establish the differential diagnosis. This article is a guide to the diagnosis and investigation of skin lesions in returning travelers; it is not intended as a comprehensive review of tropical dermatology.

Evaluation of fever in the returned traveler.

The differential diagnosis of a febrile illness in the returned traveler is extensive. The most commonly encountered tropical infections are malaria, dysentery, hepatitis, and dengue fever; a substantial number of febrile illnesses are never diagnosed. Malaria is by far the most important infection to consider in the returned traveler who presents with fever. As international travel continues to increase in popularity, the ongoing need for clinicians to broaden their knowledge of travel-related diseases is evident. The ability to recognize and manage tropical diseases in travelers is essential because the morbidity and mortality of these infections are often preventable with prompt therapy. When expertise in this area is lacking, febrile returned travelers should be referred to a tropical disease unit or an infectious disease consultant for urgent assessment.

Safety and efficacy of diphetarsone in the treatment of amoebiasis, non-pathogenic amoebiasis and trichuriasis.

Eighty-nine patients infected with Entamoeba histolytica, non-pathogenic amoebae or Trichuris trichiura were studied prospectively to determine the safety and efficacy of diphetarsone therapy. An additional 75 patients were studied retrospectively to assess further the efficacy of diphetarsone in the treatment of E. histolytica cyst passers. Side effects were noted in 9% and included gastrointestinal upset, lightheadedness and headache. Transient liver function abnormalities were recorded in 5.6%. diphetarsone was completely effective in the treatment of Dientamoeba fragilis, Entamoeba hartmanni, Iodamoeba buetschlii and Trichuris trichiura. 99% of the patients with E. histolytica, 97% of those with E. coli and 98% of those with Endolimax nana were cured.

Short-course treatment of typhoid fever with ciprofloxacin in south India.

This study assessed the performance of short-course ciprofloxacin for the treatment of 34 adult patients with culture-positive typhoid fever. Patients received ciprofloxacin, 750 mg orally twice daily for 7 d. Measurement of response was based upon time from initial treatment to fever lysis, to afebrile state, and to symptom resolution. Ciprofloxacin-treated patients defervesced in a mean of 3.21 d (+/- 0.56), with stabilization of temperature in 4.0 +/- 0.73 d. After 90 d follow-up, no relapse or carrier was identified. Side effects during therapy were minimal.

Vaccination of travelers against hepatitis A and B.

Despite the fact that effective preventive measures have become available, there has been no decline in the incidences of both hepatitis A and hepatitis B in most industrialized countries to date. This is, in part, due to the rapid increase in the number of travelers to areas of medium and high endemicity for both diseases, primarily developing countries. Targeting of travelers at risk of contracting these diseases for vaccination offers a chance of significantly reducing their incidence. Hepatitis A, an acute disease associated with poor food hygiene, is the most common vaccine-preventable infection in travelers. Hepatitis A immunity should, therefore, be considered essential for anyone visiting an area of high endemicity. In contrast, hepatitis B is a blood-borne virus which was thought, until recently, to pose a relatively low risk to the majority of travelers. However, the 1990s has seen international tourism and business travel grow faster in Europe than anywhere else in the world, with travel to areas of high endemicity for hepatitis B (Africa, Asia and South America) being commonplace. Thus the number of reported hepatitis B cases is increasing in many countries. Furthermore, there is considerable overlap of high-endemicity areas of hepatitis A and hepatitis B so that travelers are often considered to be at risk from both viruses. As well as separate hepatitis A and B vaccine preparations, a combined hepatitis A and B vaccine is now available which may offer improvements in vaccination schedule, enhanced patient compliance, and reduced cost.

Transmission of health information on leprosy from children to their families: another approach to health education.

A controlled study was carried out in the North Arcot District of Tamil Nadu, South India to determine whether health information given to schoolchildren would influence the knowledge and attitudes of their families concerning leprosy. A total of 41 children and almost all of their household members participated in the study. The study, conducted by questionnaire, involved a pre-test of knowledge and attitude about leprosy of seventh standard students and their families. After one group of children received health education about leprosy and the other received information about tuberculosis, an identical post-test questionnaire was administered to all participants. Although significant improvement in knowledge about leprosy was detected in the leprosy educated group of children compared with controls, no transmission of information on leprosy was detected in the family members of either group. The attitudes of the children who had been educated about leprosy may have been adversely affected by the health education session. The reasons for our failure to detect significant transfer of information about leprosy in this setting are discussed, as well as the need for additional research in this area.