Epidemiology of Echinococcus granulosus infection in the central Peruvian Andes.

The prevalence of human, canine, and ovine echinococcosis was determined in an endemic area of the Peruvian Andes where control programmes have not been operational since 1980. Prevalence of infection in humans was determined using portable ultrasound, chest X-rays, and an enzyme-linked immunoelectrotransfer blot (EITB) assay. Canine and ovine echinococcal prevalence was determined by microscopic stool examinations following arecoline purging for tapeworm detection and by examination of the viscera from slaughtered livestock animals, respectively. The prevalence among 407 humans surveyed was 9.1%. The frequency of disease in the liver, lung, and in both organs was 3.4%, 2.0%, and 0.2%, respectively. Portable ultrasound or portable chest X-ray has shown that, compared to adults, children under 11 years had significantly higher seropositive rates without evidence of hydatid disease (P < 0.05). Among the 104 dogs inspected for echinococcus after arecoline purging, 33 (32%) were positive for adult tapeworms. Among the 117 sheep slaughtered at the local abattoir, 102 (87%) had hydatid cysts. The prevalence of human hydatidosis in this endemic area of Peru is one of the highest in the world and nearly five times higher than previously reported in 1980. An increase in echinococcosis prevalence may result after premature cessation of control programmes.     

衣原体在冷血动物中的自然感染和实验感染

衣原体的温血动物宿主已为人们所熟知,但在冷血动物中的宿主却少受关注.文章特综述在冷血动物中:软体、两栖和爬行动物中的衣原体自然和实验感染的宿主.近年来两栖动物中的衣原体感染,已日渐受到重视,因其在作为传染源和实验感染方面,可能担负重要角色,有其重要意义.     

Cutaneous leishmaniasis in the Peruvian Andes: an epidemiological study of infection and immunity.

A prospective longitudinal survey of cutaneous leishmaniasis (Leishmania peruviana) was carried out in Peru on a study population of 4716 persons living in 38 villages (Departments of Lima, Ancash and Piura). Demographic and clinical data were collected from all individuals, and a Montenegro skin test (MST) was carried out on 72% (3418) of the study population. Each household was revisited at 3-monthly intervals for up to 2 years to detect new leishmaniasis cases; 497 people received a second MST at the end of the study. Analysis of the epidemiological data indicated that (i) 17% (16/94) of all infections were subclinical, (ii) this percentage increased significantly with age, (iii) clinical infections led to 73.9% protective immunity (95% C.I. 53.0-85.5%) and relatively permanent MST responsiveness (recovery rate = 0.0098/year; 95% C.I. 0.000-0.020/year), (iv) sub-clinical infections led to protective immunity, which was positively correlated with their MST induration size (increasing by 17.9% per mm; P < 0.0001), and a mean MST recovery rate of 0.114/year (4/421 man-months), and (v) recurrent leishmaniasis was dominated by reactivations, not by reinfections.     

A new species of Leishmania parasite from the Venezuelan Andes region.

A new form of Leishmania is described from the Venezuelan Andes region. L. garnhami n.sp. is proposed for this parasite with amastigote stages showing a peculiar and unique organelle seen with light and electron microscope. It produces cutaneous lesions in people living at a height of between 800 and 1,8000 m. in urban and rural areas; the disease is associated with Lutzomyia townsendi, the main anthropophilic sandfly in the region. The parasite is easily inoculable into hamsters and grows slowly in vitro in blood-agar media with glucose, but more prolifically without glucose.     

Spraying houses in the Peruvian Andes with lambda-cyhalothrin protects residents against cutaneous leishmaniasis

A household vector control trial was carried out in the Peruvian Andes to measure the effect of spraying inside walls and ceilings with lambda-cyhalothrin on the risk for residents of cutaneous leishmaniasis caused by Leishmania peruviana. The mortality rates of Lutzomyia verrucarum measured with WHO contact bioassay cones set on adobe walls characteristic of the endemic region indicated an LD95 for lambda-cyhalothrin of about 20 mg/m2, and no reduction in effectiveness for at least 6 months on indoor adobe walls sprayed with 25 mg/m2. A random selection of 112 houses were sprayed (starting in 1992/93) at 6-monthly intervals with a mean dose of 34 mg/m2, leaving 154 control houses (with closely matched pre-intervention measurements of incidence and sandfly abundance). Comparisons of pre- and post-intervention sandfly indoor abundance, measured at regular intervals for up to 2 years using CDC light traps, in 22 sprayed and 21 control houses demonstrated that spraying significantly reduced the indoor abundance of Lu. verrucarum by an average of 78% and of Lu. (Helcocyrtomyia) peruensis by 83%. Spraying was also associated with a significant reduction of 77% in the proportion of bloodfed sandflies collected in light traps. The proportion of susceptible householders acquiring leishmaniasis during the trial was significantly reduced by 54% as a result of spraying. The observed impact of spraying was greatest, 81% (95% confidence intervals 20-95%), when the cases detected during the first 6 months after the intervention were excluded from the analysis, suggesting a significant pre-patent period.     

Making sustainable water and sanitation in the Peruvian Andes: an intervention model

Sustainability of water supplies in remote rural communities is problematic and resource consuming. CARE has a long history of working hand in hand with remote rural communities and devising programs tailored to their needs. We present here an intervention that integrates development of water supplies and sanitation, with operation and maintenance skills development and training of health promoters that can educate from within the community that ensures the sustainability of drinking water supply systems in rural communities. The training used is innovative in that it uses a series of video-workshops which are found to be particularly useful in communities with high illiteracy rates.     

Making sustainable water and sanitation in the Peruvian Andes: an intervention model

Sustainability of water supplies in remote rural communities is problematic and resource consuming. CARE has a long history of working hand in hand with remote rural communities and devising programs tailored to their needs. We present here an intervention that integrates development of water supplies and sanitation, with operation and maintenance skills development and training of health promoters that can educate from within the community that ensures the sustainability of drinking water supply systems in rural communities. The training used is innovative in that it uses a series of video-workshops which are found to be particularly useful in communities with high illiteracy rates.     

Epidemiology of a natural focus of Leishmania braziliensis in the Pacific lowlands of Colombia. III. Natural infections in wild mammals

A natural infection of Leishmania braziliensis panamensis in the edentate, Choloepus hoffmanni is recorded from the Pacific Coast of Columbia.     

Leishmania infecting man and wild animals in Saudi Arabia. 2. Leishmania arabica n. sp

Leishmania arabica n. sp., found in the rodent Psammomys obesus in the Eastern Province of Saudi Arabia, is described. This parasite, which has also been found in a feral dog in the same area, is distinguished from the common species of the Eastern Province, L. major zymodeme LON-4, on the basis of its very distinctive isoenzyme profile (zymodeme LON-64) and kinetoplast DNA. It is morphologically indistinguishable from L. major. The new parasite has not been found in man to date and its vector is so far unknown.     

Biochemical characterization of Leishmania (Viannia) braziliensis and Leishmania (Viannia) peruviana by isoenzyme electrophoresis

Leishmanial organisms isolated from 24 patients with Andean cutaneous leishmaniasis (uta) and from 7 with sylvatic leishmaniasis in both cutaneous and mucosal forms were characterized on the basis of their isoenzyme profiles for 13 enzymes using both cellulose acetate (CA) and thin-layer starch gel (TLS) electrophoretic techniques. Malate dehydrogenase (MDH) after electrophoresis on CA or TLS and mannose phosphate isomerase (MPI) on TLS were the only enzymes of 13 examined which discriminated between the organisms from patients with uta (L. (V.) peruviana) and those with sylvatic leishmaniasis (L. (V.) braziliensis). Mannose phosphate isomerase gave more clear-cut and reproducible discrimination than did MDH on either TLS or CA, and it is suggested that MPI is a reliable enzyme marker that can be used in routine TLS electrophoresis to distinguish between L. (V.) peruviana and L. (V). braziliensis.     

Prevalence, intensity, and fertility of ovine cystic echinococcosis in the central Peruvian Andes

An abattoir survey of 212 sheep of different ages was undertaken to determine the local epidemiological transmission patterns of Echinococcus granulosus in the central Peruvian Andes. Overall prevalence of the disease in sheep in this survey (which ended in July 1996) was 77.4%, with 96% of sheep aged > or = 6 years being infected. Of 1165 cysts examined, 41.1% were fertile with a mean protoscolex viability of 73.2%. A logistic regression model for the distribution of cyst fertility and type by age, location and size is described. Mathematical modelling also determined that infection pressure on sheep was 0.44 infections per year and that the mean number of cysts increased linearly by 1.28 cysts per year. These data suggest that E. granulosus is in an endemic state in this area and control measures could drive the disease towards extinction.     

Isoenzyme characterization of Leishmania braziliensis braziliensis isolates obtained from Bolivian and Peruvian patients.

Thirty-four Leishmania isolates obtained from Bolivian and Peruvian patients infected with mucocutaneous leishmaniasis were characterized by isoenzyme electrophoresis using 10 enzymatic markers; all belonged to the subspecies L.b. braziliensis. Three isolates showed marked variation compared with the reference strain with respect to 5 or 6 enzymes. These variant isolates originated from patients with forms of the disease which were unresponsive to treatment.     

Prevalence and symptoms of Enterobius vermicularis infections in a Peruvian shanty town.

The prevalence and symptoms of pinworm infection were determined in a shanty town in Lima, Peru. In 206 families, pinworm infection rates were highest in primary school age children (42%). Approximately one-fourth of pre-school children and secondary school-age children were infected with pinworms. Two examinations detected 74% of patients who were positive after 5 examinations. Symptoms often attributed to pinworm infection, such as perianal itching enuresis, and teeth grinding, occurred in a similar proportion of infected children (15%, 17%, 13%, respectively) and non-infected subjects (11%, 13%, 11%, respectively). Enuresis was more common in primary school-age children with high pinworm egg counts than in their non-infected contemporaries. 52% (28/54) of children under 5 years old became reinfected within 6 months of effective treatment. In a community where water is scarce and hand washing is infrequent, the high rate of perianal itching is probably an important source of faecal-oral contamination. The low morbidity and high reinfection rate make routine treatment of pinworm infection in third world countries a low priority, except when clinically indicated.     

Incidence of and risk factors for surgical-site infections in a Peruvian hospital.

OBJECTIVE: To determine the incidence of and risk factors for surgical-site infections (SSIs) after abdominal surgery. DESIGN: A cohort study was conducted from January to June 1998. CDC criteria for SSI and the NNIS System risk index were used. SETTING: A tertiary-care hospital in Peru. PATIENTS: Adult patients undergoing abdominal surgery who consented were enrolled and observed until 30 days after surgery. Patients who had undergone surgery at another hospital or who died or were transferred to another hospital within 24 hours after surgery were excluded. RESULTS: Four hundred sixty-eight patients were enrolled. Their mean age was 37.2 years. One hundred twenty-five patients developed SSIs, 18% of which were identified after discharge. The overall incidence rate (IR) was 26.7%. The IR was 13.9% for clean, 15.9% for clean-contaminated, 13.5% for contaminated, and 47.2% for dirty interventions. The IR was 3.6% for NNIS System risk index 0 and 60% for index 3. Risk factors for SSI on logistic regression analysis were dirty or infected wound (RR, 3.8; CI95, 1.7-8.4), drain use longer than 9 days (RR, 6.0; CI95, 2.5-12.5), and length of surgery greater than the 75th percentile (RR, 2.1; CI95, 1.0-4.4). Patients with SSI had a longer hospital stay than did non-infected patients (14.0 vs 6.1 days; p < .001). CONCLUSIONS: SSI is a major problem in this hospital, which has a higher IR (especially for clean interventions) than those of developed countries. In developing countries, prevention of SSI should include active surveillance and interventions targeting modifiable risk factors.     

Leishmania infecting man and wild animals in Saudi Arabia. 1. General survey

Using up to 13 enzymes, biochemical characterization of 75 isolates of Leishmania made from man, wild animals and sandflies from a wide variety of localities in the Kingdom of Saudi Arabia has revealed the presence of L. major (two similar zymodemes), L. tropica (two zymodemes) and a parasite of the L. donovani-L. infantum complex. Zymodeme LON-4 of L. major has been found in 52 of 53 isolates so far characterized from man, from one specimen of Phlebotomus papatasi, from 15 Psammomys obesus, from one Meriones libycus and from one dog. One isolate from man has been identified as a new variant of L. major. This variant, zymodeme LON-65, varies from zymodeme LON-4 in a single enzyme. While this is the only example of zymodeme LON-65 identified so far, zymodeme LON-4 has also been obtained from Kuwait and Iraq. These are the first reports of L. major in Meriones libycus from Saudi Arabia and the first proven isolate from the dog in any country. L. tropica was identified from only two foci, whereas L. major appears to be widely distributed in the Kingdom. Two infants with kala-azar were found to be infected with a parasite apparently identical to zymodeme LON-42 of L. donovani (sensu lato) which also occurs in the highlands of Ethiopia.