The challenge of improving boiling: lessons learned from a randomized controlled trial of water pasteurization and safe storage in Peru.

Boiling is the most common method of household water treatment in developing countries; however, it is not always effectively practised. We conducted a randomized controlled trial among 210 households to assess the effectiveness of water pasteurization and safe-storage interventions in reducing Escherichia coli contamination of household drinking water in a water-boiling population in rural Peru. Households were randomized to receive either a safe-storage container or a safe-storage container plus water pasteurization indicator or to a control group. During a 13-week follow-up period, households that received a safe-storage container and water pasteurization indicator did not have a significantly different prevalence of stored drinking-water contamination relative to the control group [prevalence ratio (PR) 1·18, 95% confidence interval (CI) 0·92-1·52]. Similarly, receipt of a safe-storage container alone had no effect on prevalence of contamination (PR 1·02, 95% CI 0·79-1·31). Although use of water pasteurization indicators and locally available storage containers did not increase the safety of household drinking water in this study, future research could illuminate factors that facilitate the effective use of these interventions to improve water quality and reduce the risk of waterborne disease in populations that boil drinking water.

Herpes simplex virus encephalitis in Peru: a multicentre prospective study.

Herpes simplex virus (HSV) is one of the most commonly identified infectious aetiologies of encephalitis in North America and Europe. The epidemiology of encephalitis beyond these regions, however, is poorly defined. During 2009-2012 we enrolled 313 patients in a multicentre prospective study of encephalitis in Peru, 45 (14·4%) of whom had confirmed HSV infection. Of 38 patients with known HSV type, 84% had HSV-1 and 16% had HSV-2. Patients with HSV infection were significantly more likely to present in the summer months (44·4% vs. 20·0%, P = 0·003) and have nausea (60·0% vs. 39·8%, P = 0·01) and rash (15·6% vs. 5·3%, P = 0·01) compared to patients without HSV infection. These findings highlight differences in the epidemiology and clinical presentation of HSV encephalitis outside of the Northern Hemisphere that warrant further investigation. Furthermore, there is an urgent need for improved HSV diagnostic capacity and availability of intravenous acyclovir in Peru.

In men at risk of HIV infection, IgM, IgG1, IgG3, and IgA reach the human foreskin epidermis.

We profiled the humoral response in the penis, an area that has been minimally explored but may be relevant for protecting insertive men against HIV and other sexually acquired infections. Comparing paired tissue samples from 20 men at risk of HIV infection, foreskin contains less immunoglobulin A (IgA) and more IgG2 than colon. Using foreskin dermal and epidermal explants and paired plasma from 17 men, we examined Ig accumulation by normalizing Ig to human serum albumin (HSA) transudation. Dermal IgM, IgG2, IgA, and IgE ratios were greater than that in plasma, suggesting there is local antibody secretion at the dermis. Local Ig transcription was concentrated at the inner rather than the outer foreskin, and inner foreskin Ig ratios did not correlate with blood, indicating that localized production can contribute to the foreskin response. IgM, IgG1, IgG3, and IgA have preferential access to the foreskin epidermis, whereas IgG2, IgG4, and IgE are restricted to the dermis. Lastly, Ad5-specific IgA was selectively present in the colon, whereas foreskin Ad5 IgG was mainly derived from blood, and reached the inner epidermis at higher ratios than the outer (P<0.002). In summary, the foreskin antibody response combines local and systemic sources, and there is selective isotype accumulation in the epidermis.

Lubricant use among men who have sex with men reporting receptive anal intercourse in Peru: implications for rectal microbicides as an HIV prevention strategy.

This study assessed lubricant use during receptive anal intercourse (RAI) among Peruvian men who have sex with men (MSM) and willingness to use a hypothetical rectal microbicide (RM) formulated as a lubricant to prevent HIV infection. Data were collected from 843 Peruvian MSM for the 2008 HIV Sentinel Surveillance using a computerized self-interview. Half of the participants reported using a lubricant with their last sex partner during RAI, while 77% were willing to use a lubricant to prevent HIV transmission. Lubricant use with last sex partner was significantly associated with unprotected RAI (odds ratio [OR] 1.59, 95% confidence interval [CI], 1.23, 2.05; P < 0.001) and willingness to use a future lubricant RM (OR 1.56, 95% CI: 1.24, 1.95; P < 0.001). This study provides information on the behaviours associated with lubricant use and non-use among MSM practicing RAI in Peru that should inform future RM studies in Peru and other Latin American countries.

Molecular characterization of the human immunodeficiency virus type 1 among children in Lima, Peru.

In Peru, there is a lack of information on molecular analysis in pediatric human immunodeficiency virus (HIV) infection. At present, the mother-to-child transmission rate is estimated at approximately 2-4%. The objective of this study was to assess the molecular epidemiology of HIV-1 in infected children. Children with suspected or confirmed pulmonary tuberculosis were evaluated at two public hospitals between 2002 and 2007. Whole blood samples were obtained from 90 HIV-positive children, who were confirmed to be positive by enzyme-linked immunosorbent assay and Western blot. The specimens were subjected to envelope heteroduplex mobility assay (env HMA) followed by gag and pol gene region sequence analysis. Subtype B was found in 88 (98%) of 90 children and 2 (2%) children were subtype BF recombinants. This is the first report of recombinant HIV strains in HIV-infected children in Peru. Understanding the origin, diversity, and spread of HIV strains worldwide will be necessary for the development of an effective vaccine that targets pediatric populations throughout the world.

Human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis: viral load and muscle tone are correlated.

Human T-lymphotropic virus type 1 (HTLV-1) infections are associated with varying degrees of HTLV-1 viral load and spasticity. Increased viral load is associated with higher risk of developing HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The authors performed a cross-sectional study of 24 people with HAM/TSP in Lima, Perú, to determine if higher HTLV-1 viral load was correlated with increased muscle tone, measured with a device providing quantitative spasticity assessment (QSA). Median HTLV-1 viral load was 17.0 copies/100 peripheral blood mononuclear cells and QSA value was 39.9 Newton-meters/radian. HTLV-1 viral load was significantly correlated with QSA value (Spearman rho = .48, P = .02), suggesting viral load may play a role in expression of symptomatic neurologic disease. Longitudinal studies are needed to determine if treatments that reduce viral load will reduce muscle tone.

Seroprevalence of and risk factors for HIV-1 infection among female commercial sex workers in South America.

OBJECTIVE: Assessment of HIV prevalence and associated risk behaviours among female commercial sex workers (FCSW) across major cities in South America. METHODS: Seroepidemiological, cross sectional studies of 13 600 FCSW were conducted in nine countries of South America during the years 1999-2002. Participants were recruited in brothels, massage parlours, hotels, and streets where anonymous questionnaires and blood samples were collected. HIV infection was determined by enzyme linked immunosorbent assay (ELISA) screening and western blot confirmatory tests. RESULTS: The overall HIV seroprevalence was 1.2% (range 0.0%-4.5%). The highest HIV seroprevalences were reported in Argentina (4.5%) and Paraguay (2.6%); no HIV infected FCSW were detected in Venezuela and Chile. Consistent predictors of HIV seropositivity were: (1) a previous history of sexually transmitted infections (STI, AORs = 3.8-8.3), and (2) 10 years or more in commercial sex work (AORs = 2.2-24.8). In addition, multiple (> or =3) sexual contacts (AOR = 5.0), sex with foreigners (AOR = 6.9), use of illegal drugs (AOR = 3.2), and marijuana use (AOR = 8.2) were associated with HIV seropositivity in Southern Cone countries. CONCLUSIONS: Consistently low HIV seroprevalences were detected among FCSW in South America, particularly in the Andean region. Predictors of HIV infection across the continent were STI and length of commercial sex work; however, use of illegal drugs, especially marijuana, and sexual contacts with foreigners were also found to be associated risk factors in the Southern Cone region. Interventions for the control of HIV and other STI need to be region and country specific; drug use appears to have an ever increasing role in the spread of HIV among heterosexually active populations.

Neurocysticercosis: association between seizures, serology, and brain CT in rural Peru.

BACKGROUND: Neurocysticercosis (NCC) is the commonest helminthic CNS infection and the main cause of adult-onset seizures in developing countries, also frequent in industrialized countries because of immigration from endemic zones. Although NCC is commonly seen in individuals with seizures in endemic areas, its role as a cause of epilepsy has been questioned on the basis of the poor methodology of published studies. OBJECTIVE: To determine, in a cysticercosis-endemic area of the northern Peruvian coast, the frequency of 1) epileptic seizures, 2) serum antibodies to Taenia solium, 3) NCC-compatible findings on brain CT, and 4) the associations between these variables. METHODS: A community-wide screening survey for possible seizure cases was performed using a validated questionnaire. Positive respondents were later examined in the field by neurologists. Seizure cases were categorized as single seizure, active epilepsy, or inactive epilepsy. Serology was performed for all consenting individuals using immunoblot. Noncontrast brain CT scans were performed in all individuals with seizures and two groups of control subjects without seizures (seropositive and seronegative). RESULTS: The screening survey was applied to 903 permanent residents. Most positive respondents (114/137 [83.2%]) were examined by neurologists. The overall prevalence of epilepsy was 32.1 per 1,000 and that of active epilepsy was 16.6 per 1,000. Seroprevalence was 24.2% (200/825). Seroprevalence was associated with seizures (odds ratio 2.14; p = 0.026). Brain CT abnormalities compatible with NCC were more frequent in individuals with seizures and in those seropositive. CONCLUSION: In this hyperendemic area, an important proportion of seizure cases are associated with neurocysticercosis as demonstrated by serology or brain CT.

Quantitative assessment of spasticity in human T-cell lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis.

People with human T-cell lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) develop spasticity. The authors examined 34 patients with HAM/TSP in Perú using a device that measures tone in the gastroc-soleus-Achilles tendon unit and provides a quantitative spasticity assessment (QSA). Tone in the 34 patients was more than double that of women with asymptomatic HTLV-I infection. The device may help to track progression in HTLV-I infection.

Epidemiology of transfusion-transmitted infections among multi-transfused patients in seven hospitals in Peru.

BACKGROUND: Transfusion-transmitted infections (TTIs) constitute a major health problem worldwide where routine screening of blood or blood products is improperly done, and where non-medical injecting medications and/or drug use are prevalent. Prevalence and risk factors vary by geographic location and by the specific TTI (including HIV-1, HBV, HCV and HTLV-I). OBJECTIVE: To determine the prevalence and risk factors associated with TTIs among a sample of multi-transfused adult patients in Peru. STUDY DESIGN: A cross-sectional multi-center study was conducted across seven major hospitals in Peru from February 2003 to September 2004. Self-reported behavior information (medical procedures, number of sexual partners, and drug use history) was analyzed, along with a review of exposure history from hospital medical records. Prevalences were calculated by TTI for different exposures, along with unadjusted and adjusted odds ratios for infection risk. RESULTS: Overall, 192 (54.7%) of 351 multi-transfused patients were found infected with one or more TTIs. Number of transfusion units, years of transfusion history (6 or more), and number of treatment facilities (2 or more) were associated with HCV infection. Hemodialysis history was a common risk factor associated with HBV, HCV and HTLV-I infection. HIV infection was associated only with total number of transfusion units received. CONCLUSIONS: High prevalences of HBV and HCV infection were found among Peruvian multi-transfused patients and were associated with a past history and number of blood transfusions, as well as with past hemodialysis procedures. TTIs continue to represent a significant public health problem in Peru. Continued vigilant attention to blood safety procedures, including universal screening and health care provider education, is recommended.

Seroprevalence of and risk factors for HIV-1 infection among South American men who have sex with men.

OBJECTIVES: Sex among men constitutes an important route of transmission for HIV type 1 (HIV-1) in Latin America. Seeking better understanding of risk behaviours in this region, we determined the seroprevalence, potential risk factors, and geographic distribution of HIV-1 among groups of men who have sex with men (MSM). METHODS: Seroepidemiological, cross sectional studies of 13,847 MSM were conducted in seven countries of South America during the years 1999-2002. Volunteers were recruited in city venues and streets where anonymous questionnaires and blood samples were obtained. HIV-1 infection was determined by enzyme linked immunosorbent assay (ELISA) screening and western blot (WB) confirmatory tests. RESULTS: HIV-1 seroprevalence varied widely (overall 12.3%, range 11.0%-20.6%). The highest HIV-1 seroprevalence was noted in Bolivia (20.6%) and the lowest in Peru (11.0%). Predictors of HIV-1 infection varied among countries; however, a history of previous sexually transmitted disease (STD) was associated with a consistent increased risk (ORs=1.9-2.9, AORs=1.8-2.7). Multiple weekly sexual contacts was found to represent a secondary risk factor in Ecuador, Peru, and Argentina (ORs=1.6-2.9, AORs=1.6-3.1), whereas use of drugs such as cocaine was found to increase risk in Bolivia, Uruguay, and Paraguay (ORs=2.5-6.5, AORs=2.6-6.1). CONCLUSION: The results of this study illustrate an elevated HIV-1 seroprevalence among MSM participants from Andean countries. A previous STD history and multiple partners predicted HIV-1 infection in the seven countries of South America. In Southern Cone countries, HIV-1 infection was also associated with use of illegal drugs such as cocaine.

Documentation of subtype C HIV Type 1 strains in Argentina, Paraguay, and Uruguay.

HIV subtypes B, F, and BF recombinants have been previously reported in South America. This report describes the presence of HIV-1 subtype C infection in the countries of Argentina, Uruguay, and Paraguay dating back to at least 1999. Surveillance for uncommon non-B/non-F subtype viruses circulating in South America has been conducted in samples obtained from nine countries. Peripheral blood mononuclear cells (PBMC), dried filter paper (FP), and fresh blood (FB) samples were collected from HIV-positive patients from Ecuador, Colombia, Venezuela, Peru, Chile, Bolivia, Argentina, Uruguay, and Paraguay. From a total of 2962 HIV seropositive samples examined during a 9-year period (1995-2003), only 11 (0.4%) were found to be infected with non-B/non-F HIV variants. Eight of these 11 strains were determined to be subtype C by heteroduplex mobility assay (HMA). Five of these 8 strains were further characterized by sequencing and phylogenetic analysis of the protease (Pro) and reverse transcriptase (RT) region of the genome and two were sequenced full length. One of the strains was found to be a unique BC recombinant. The spread of a third subtype of HIV, subtype C, should raise the question of its potential future role in the HIV epidemic in this region.

Human T cell lymphotropic virus type 1 infection and early neurologic development: a pilot study of 48 children.

To determine whether human T cell lymphotropic virus type 1 (HTLV-1) infection is associated with delayed neurological development, we examined 48 Peruvian children with exposure to HTLV-1 who were identified at the Instituto Materno-Perinatal. Compared with 38 HTLV-1-seronegative children, the 10 seropositive children did not have higher rates of neurodevelopmental delay. Long-term follow-up is planned.