HIV-1 prevalence and factors associated with infection in the conflict-affected region of North Uganda

Background

Since 1986, northern Uganda has been severely affected by civil strife with most of its population currently living internally displaced in protected camps. This study aims at estimating the HIV-1 prevalence among this population and the factors associated with infection.

Methods

In June-December 2005, a total of 3051 antenatal clinics attendees in Gulu, Kitgum and Pader districts were anonymously tested for HIV-1 infection as part of routine sentinel surveillance. Factors associated with the infection were evaluated using logistic regression models.

Results

The age-standardised HIV-1 prevalence was 10.3%, 9.1% and 4.3% in the Gulu, Kitgum and Pader district, respectively. The overall prevalence in the area comprised of these districts was 8.2% when data was weighted according to the districts' population size. Data from all sites combined show that, besides older women [20–24 years: adjusted odds ratio (AOR) = 1.96, 95% confidence interval (CI): 1.29–2.97; 25–29 years: AOR = 2.01, 95% CI: 1.30–3.11; ≥ 30 years: AOR = 1.91, 95% CI: 1.23–2.97], unmarried women (AOR = 1.47, 95% CI: 1.06–2.04), and those with a partner with a non-traditional occupation (AOR = 1.62, 95% CI: 1.18–2.21), women living outside of protected camps for internally displaced persons have a higher risk of being HIV-1 infected than internally displaced women (AOR = 1.55, 95% CI: 1.15–2.08).

Conclusion

Although published data from Gulu district show a declining HIV-1 prevalence trend that is consistent with that observed at the national level since 1993, the prevalence in North Uganda is still high. Internally displaced women have a lower risk of being infected probably because of their reduced mobility and accessibility, and increased access to health prevention services.

A high prevalence of HIV-1 infection among pregnant women living in a rural district of north Uganda severely affected by civil strife

This study aims at estimating the recent trends in HIV-1 prevalence and the factors associated with infection among pregnant women in the Gulu District of north Uganda, a rural area severely affected by civil strife. In 2000-2003, a total of 4459 antenatal clinic attendees of Lacor Hospital were anonymously tested for HIV-1 infection. The overall and age-specific prevalence did not show any significant trend over time. The age-standardized prevalence slightly declined, from 12.1% in 2000 to 11.3% in 2003. Increased age [20-24 years: adjusted odds ratio (AOR) 1.63; 95% CI 1.18-2.25; >or=25 years: AOR 2.56; 95% CI 1.91-3.44], residence in urban areas (AOR 1.76; 95% CI 1.41-2.18), being unmarried (AOR 1.60; 95% CI 1.27-2.01), increased age of partner (25-34 years: AOR 1.87; 95% CI 1.29-2.73; >or=35 years: AOR 2.68; 95% CI 1.72-4.16), modern occupation of partner (AOR 1.98; 95% CI 1.53-2.58), and short time of residence at the current address (AOR 1.36; 95% CI 1.05-1.76) were associated with infection. The HIV-1 prevalence in this rural district is high and similar to that observed in urban antenatal clinics, probably reflecting the effect of the last 18 years of civil strife.

Differences in fertility by HIV serostatus and adjusted HIV prevalence data from an antenatal clinic in northern Uganda

OBJECTIVES

To estimate differences in fertility by HIV serostatus and to validate an adjustment method for estimating the HIV prevalence in the general female population using data from an antenatal clinic.

METHODS

We used Cox regression models to retrospectively estimate the age-specific relative fertility (RF) of HIV-positive compared to HIV-negative women among 3314 antenatal clinic attenders in northern Uganda. RF and the age distribution of women in the general female population were used to extrapolate the antenatal clinic-based HIV prevalence. This procedure was indirectly validated by comparing the adjusted estimate with those based on standard adjustment factors derived from general female populations in Uganda and Tanzania.

RESULTS

HIV-positive women reported a lower fertility than HIV-negative women [age-adjusted RF=0.83, 95% confidence interval (CI): 0.75-0.93]. Except for girls aged 15-19 (RF=0.96, 95% CI: 0.74-1.24) HIV-positive women in all age groups were less fertile (20-24 year: RF=0.83, 95% CI: 0.67-1.01; 25-29 years: RF=0.79, 95% CI: 0.62-1.00; 30-49 year: RF=0.79, 95% CI: 0.65-0.96]. Adjusting the antenatal clinic-based HIV prevalence (11.6%) for these differences yields a higher estimate (13.8%) that is lower than those based on standard adjustment factors derived from general female populations (from 14.6% to 17.7%).

CONCLUSIONS

The age-specific pattern of differential fertility by HIV serostatus derived from antenatal clinic data is consistent with findings from population-based studies conducted in Africa. However, differences in fertility between HIV positive and HIV-negative clients underestimate those in the general female population yielding inaccurate estimates when used to extrapolate the HIV prevalence.

Using prevalence data from the programme for the prevention of mother-to-child-transmission for HIV-1 surveillance in North Uganda

OBJECTIVES

To validate the use of data from a programme for the prevention of mother-to-child transmission (PMTCT) in estimating HIV-1 prevalence in North Uganda.

METHODS

The study was conducted at St. Mary's Hospital Lacor. We compared the estimated prevalence for 3580 attendees at the antenatal clinic who were selected for anonymous surveillance to that for 6785 pregnant women who agreed to undergo voluntary counselling and testing (VCT) for enrolment in the PMTCT programme. Log-binomial regression models were used to identify the factors associated with both VCT uptake and HIV-1 infection, which could bias the prevalence estimates based on PMTCT data.

RESULTS

In 2001-2003, the age-standardized prevalence was similar (11.1% in the anonymous surveillance group and 10.9% in the VCT group). The estimates were also similar when compared for each year tested. Analogously, no important differences were observed in age-specific prevalence. Of the factors associated with HIV-1 infection, only time of residence at current address [prevalence proportion ratio (PPR) = 1.05; 95% confidence interval (CI), 1.00-1.10], marital status (PPR = 1.05; 95% CI, 1.01-1.10) and partner's occupation (PPR = 1.05; 95% CI, 1.01-1.10) were associated with VCT uptake, yet the associations were weak.

CONCLUSIONS

The prevalence estimated based on the VCT data collected as part of the PMTCT programme could be used for HIV-1 surveillance in North Uganda. At the national level, however, it needs to be evaluated whether PMTCT data could replace, or instead be combined with, the data from sentinel surveillance.

The disease profile of poverty: morbidity and mortality in northern Uganda in the context of war, population displacement and HIV/AIDS

The population of Gulu District (northern Uganda) has been severely incapacitated by war, epidemics and social disruption. This study is aimed at describing disease patterns and trends in this area through a retrospective analysis of discharge records for 155205 in-patients of Lacor Hospital in the period 1992-2002. The burden of infectious diseases in childhood is overwhelming, with malaria accounting for the steepest increase in admissions. Admissions for war-related injuries and malnutrition fluctuated with the intensity of the war and the severity of famine. Emerging and re-emerging infections, such as HIV/AIDS, tuberculosis and Ebola, accounted for a heavy disease burden; however, there has been a trend for admissions related to HIV/AIDS and tuberculosis to decrease since the implementation of community-based services. Vulnerable groups (infants, children and women) accounted for 79.8% of admissions. Long-term war, population displacement, the collapse of social structures and the breakdown of the health system place people at a much greater risk of persistent, emerging and re-emerging infectious diseases, malnutrition and war-related injuries, shaping the 'disease profile of poverty'. Most of the disease burden results from infectious diseases of childhood, whose occurrence could be dramatically reduced by low-cost and effective preventive and curative interventions.

The burden of traditional practices, ebino and tea-tea, on child health in Northern Uganda

Traditional medical practices persist today in Northern Uganda; for example, the operations of ebino and tea-tea are frequently performed in childhood. Ebino, or "false teeth", refers to gingival swellings during the eruption of the primary canine teeth in infants, and consists of the extraction of deciduous canine tooth buds. Tea-tea consists of systematic cuts made on the chest wall when the child has difficulty in breathing. The objectives of this study are to describe the morbidity and mortality related to complications arising from the ebino and tea-tea procedures among children admitted to the paediatric ward of St. Mary's Hospital Lacor in 1999, and to estimate the prevalence of ebino and tea-tea among children aged 0-4 years attending, for any cause, the child welfare department (CWD) of the hospital. The prevalence survey consisted of the examination of 1,995 children attending CWD during a four-week period in 1999 to look for missing primary canine teeth (ebino), and for "therapeutic" cuts on the chest wall (tea-tea). In the difficult context of war and social disruption prevailing in Northern Uganda, sustainable methods of data collection and analysis should be utilised to support evidence-based decision-making.

Ebola hemorrhagic fever transmission and risk factors of contacts, Uganda

From August 2000 through January 2001, a large epidemic of Ebola hemorrhagic fever occurred in Uganda, with 425 cases and 224 deaths. Starting from three laboratory-confirmed cases, we traced the chains of transmission for three generations, until we reached the primary case-patients (i.e., persons with an unidentified source of infection). We then prospectively identified the other contacts in whom the disease had developed. To identify the risk factors associated with transmission, we interviewed both healthy and ill contacts (or their proxies)who had been reported by the case-patients (or their proxies) and who met the criteria set for contact tracing during surveillance. The patterns of exposure of 24 case-patients and 65 healthy contacts were defined, and crude and adjusted prevalence proportion ratios (PPR) were estimated for different types of exposure. Contact with the patient's body fluids (PPR = 4.61%, 95% confidence interval 1.73 to 12.29) was the strongest risk factor, although transmission through fomites also seems possible.

Estimating HIV prevalence and the impact of HIV/AIDS on a Ugandan hospital by combining serosurvey data and hospital discharge records

OBJECTIVE

To estimate the disease-specific HIV prevalence in a northern Ugandan hospital and to evaluate the impact of HIV/AIDS on hospital services.

DESIGN

HIV serosurvey and analysis of routinely compiled hospital records.

METHODS

The serosurvey was conducted among all 352 patients admitted to the medical ward of the Lacor Hospital in March 1999 (this ward consists of 3 units: general medicine, tuberculosis, and cancer). The impact on hospital services was estimated using the hospital discharge records for all 3447 patients admitted in 1999, in combination with serosurvey data, and was expressed as the percentage of bed-days attributable to HIV-positive patients.

RESULTS

The overall HIV prevalence was 42.0% (52.6, 44.6, and 13.2% in the general medicine, tuberculosis, and cancer units, respectively). The disease-specific prevalence ranged from 45-65% for patients with tuberculosis, pneumonia, malaria, and enteritis. HIV-positive patients, compared with HIV-negative patients, had a higher in-hospital mortality (14.6 vs. 3.0%) and a lower average length of stay (41.4 vs. 48.9 days). AIDS cases accounted for 5.0% of hospital admissions, 4.1% of bed-days, and 11.5% of deaths. When considering all HIV-positive patients, these accounted for 37.2% of the bed-days.

CONCLUSIONS

Knowledge of disease-specific HIV prevalence and of the patterns of HIV-related diseases is crucial for early case management. The impact of HIV-positive patients on hospital services is quite high, accounting for >1/3 of the bed-days in 1999. Providing a continuum of care through inpatient, outpatient, and outreach home care services probably represents the only means of relieving the pressure on overloaded hospitals.

Evaluating two adjustment methods to extrapolate HIV prevalence from pregnant women to the general female population in sub-Saharan Africa

OBJECTIVE

To evaluate two methods for estimating HIV prevalence among the general female population of reproductive age by adjusting data observed among antenatal clinic (ANC) attendees.

METHODS

We adjusted the HIV prevalence among ANC attendees in Fort Portal (Uganda; 1994-1995), Mwanza municipality (Tanzania; 1990-1991), rural Mwanza (Tanzania; 1991-1993), Mposhi district (Zambia; 1994), Chelston (Lusaka, Zambia; 1994, 1996 and 1998) and Ndola (Zambia; 1998), using firstly a method that accounts for differences in age-specific fertility by HIV serostatus and secondly a method that accounts for differences in HIV prevalence by fertility risk category and parity.

RESULTS

The non-adjusted HIV prevalence among ANC attendees underestimates the prevalence among the general female population by 8.0% in Chelston in 1998 and by between 20.7% and 31.9% in all other cases. The adjusted prevalence obtained using the first method underestimates the prevalence among the general female population by about 0.5% in Fort Portal and Mposhi; it overestimates that observed in Chelston in 1994 and 1996 by about 3.5%, and that observed in Ndola, urban Mwanza and rural Mwanza, by 6.5%, 10.6% and 12.8%, respectively. The second method (applied for only four sites) provides an overestimate of 7.0% in Chelston in 1994 and an underestimate of 3.8% and 2.1% in Ndola and rural Mwanza, respectively. Both adjustment methods overestimate the 1998 prevalence in Chelston, producing less accurate estimates than the non-adjusted data.

CONCLUSIONS

The HIV prevalence among women in the general population could be estimated fairly accurately by these methods in settings with mature epidemics.

Evaluation of immune activation in HIV-infected and uninfected African individuals by single-cell analysis of cytokine production

Immune activation has been observed in HIV-infected and uninfected Africans, among whom it is thought to modify interaction between the immune system and HIV. To characterize this phenomenon accurately, in-depth immunologic analyses were performed in a rural African population. Freshly drawn peripheral blood mononuclear cells (PBMCs) of HIV-infected African (from Gulu, Uganda) and Italian antiviral-naive patients and those of uninfected Ugandan and Italian study subjects were analyzed. Individuals were matched for age and sex and determined to be free from parasitic infections. Intracellular cytokines were measured in mitogen (M)- and gp160 peptides + staphylococcal enterotoxin B and alpha CD28 (env)-stimulated T lymphocytes. Interferon (IFN)-gamma-producing CD8(+) T cells were quantified in an enzyme-linked immunosorbent assay. Results showed that M-stimulated production of interleukin (IL)-10 and tumor necrosis factor (TNF)-alpha increases in CD4(+) and CD8(+) cells of African infected patients and uninfected study subject; and that env-stimulated IL-10 and TNF-alpha production is increased in CD8(+) T lymphocytes of African HIV-infected patients. M- and env-stimulated IFN-gamma-producing CD8(+) T cells were reduced in African participants and not increased by preincubation with alpha IL-10 monoclonal antibody. This is the first set of data that has reported immune activation in rural Africa by single-cell analysis of cytokine production. These results help in defining the immunologic background to be considered in the design of therapeutic and vaccine-based approaches to HIV infection in an African setting.

HIV, malaria parasites, and acute febrile episodes in Ugandan adults: a case-control study

BACKGROUND

In sub-Saharan Africa, co-infection with HIV and malaria is probably very common. Although an interaction between the two infections is biologically plausible, it has not been investigated thoroughly.

OBJECTIVES

To evaluate the association firstly between co-infection with HIV and malaria parasites and the occurrence of acute fever, and secondly between HIV infection and clinical malaria, defined as the presence of acute fever and malaria parasites.

METHODS

A hospital-based case-control study was conducted in Gulu District (northern Uganda), an area endemic for malaria and with a high HIV prevalence. HIV testing and malaria parasite quantification were performed on 167 consecutive adult out-patients with acute fever and no signs or symptoms of localized infection, and on 134 consecutive adult in-patients without fever who were admitted for non-HIV-related trauma or elective surgery.

RESULTS

No significant association with acute fever was observed for single infection with either malaria parasites [adjusted odds ratio (AOR), 1.75; 95% confidence interval (CI), 0.73-4.21] or HIV (AOR, 1.01; 95% CI, 0.51-2.03), whereas a significant association was observed for co-infection (AOR, 9.75; 95% CI, 1.19-80.00). An association was found between HIV infection and clinical malaria (AOR, 2.34; 95% CI, 0.89-6.17); the association became statistically significant when the definition of clinical malaria included a cut-off for parasite density (50th percentile; i.e., 586 parasites/microl; AOR, 3.61; 95% CI, 1.04-12.52).

CONCLUSIONS

Despite the limited statistical power, the results of our study show an association between HIV infection and clinical malaria; if confirmed, this finding could be important for public health in sub-Saharan Africa.

The increasing burden of infectious diseases on hospital services at St Mary's Hospital Lacor, Gulu, Uganda

To evaluate the impact of infectious diseases on hospital services in Northern Uganda, a retrospective analysis of discharge records concerning 70,304 inpatients admitted to the Lacor Hospital (Gulu, Uganda) during the period 1992-1997 was performed. Children less than five years old represented 46.5% of the admissions, and the burden of infectious diseases on pediatric admissions increased over time, especially due to malaria and measles. Infectious diseases accounted for 7 of the 10 leading causes of admission. The most frequent cause was malaria (21.8% of total). The second leading infectious disease resulting in admission was respiratory tuberculosis (6.2%); given the long hospital stay, this is the most important disease in terms of hospital bed days (24.6%). Infectious diseases have represented a progressively heavy burden on hospital services, mostly due to pediatric admissions. Respiratory tuberculosis and malaria represent nearly one-third of the overall burden in terms of hospital bed days.

Impact of insecurity, the AIDS epidemic, and poverty on population health: disease patterns and trends in Northern Uganda

A retrospective analysis of the discharge records of 186,131 inpatients admitted to six Ugandan hospitals during 1992-1998 was performed to describe the disease patterns and trends among the population of Northern Uganda. In all hospitals, malaria was the leading cause of admission and the frequency of admissions for malaria showed the greatest increase. Other conditions, such as malnutrition and injuries, mainly increased in the sites affected by civil conflict and massive population displacement. Tuberculosis accounted for the highest burden on hospital services (approximately one-fourth of the total bed-days), though it showed a stable trend over time. A stable trend was also observed for acquired immunodeficiency syndrome (AIDS), which is in contrast to the hypothesis that AIDS patients have displaced other patients in recent years. In conclusion, preventable and/or treatable communicable diseases, mainly those related to poverty and poor hygiene, represent the leading causes of admission and death, reflecting the socioeconomic disruption in Northern Uganda.

Trend in HIV-1 prevalence in an antenatal clinic in North Uganda and adjusted rates for the general female population

OBJECTIVES

To estimate HIV-1 prevalence among women attending an antenatal clinic in the Gulu District (North Uganda) and, based on these data, among the district's female population.

METHODS

Anonymous HIV-1 screening was performed for 8555 antenatal clinic attendees aged 15-39 years in the period 1993-1997. The results were used to estimate the prevalence among the district's female population, accounting for differences in fertility rates by HIV-1 serostatus.

RESULTS

Among antenatal clinic attendees, HIV-1 prevalence showed a significant linear decrease (P < 0.001), from 26.0% in 1993 [95% confidence Interval (CI), 23.2-29.0%] to 16.1% in 1997 (95% CI, 14.8-17.5%). This decrease was mostly due to a marked decrease until 1995 (14.3%; 95% Cl, 12.7-16.0%) and was more pronounced among women aged under 30 years (P < 0.001), from both urban and rural areas (P < 0.001). The risk of being infected was higher among women from urban areas (Gulu Municipality), both over the entire period (adjusted prevalence proportion ratio = 1.54; 95% CI, 1.40-1.68) and by individual year. The estimated prevalence for the 15-39-year-old female population, standardized by age and area of residence, decreased from 25.4% in 1993-1994 to 17.8% in 1996-1997; these rates were 1.22 and 1.28 times higher, respectively, than those among antenatal clinic attendees.

CONCLUSIONS

The trend of decrease among young women, for whom changes in HIV-1 prevalence more closely reflect incidence, could be partially due to a reduction in risk behaviour and a consequent decreasing incidence. Differences in fertility rates by HIV-1 serostatus should be addressed when using antenatal clinic data to estimate prevalence among the general female population.

'Killer' canines: the morbidity and mortality of ebino in northern Uganda

In northern Uganda, unerupted primary canine teeth are commonly extracted because they are believed to cause diarrhoea, vomiting, and fever. This practice, known as ebino, is performed under very crude conditions often using unclean tools. To evaluate the morbidity and mortality of complications related to ebino, we retrospectively analysed discharge records from the paediatric ward of Lacor Hospital, Gulu. In the period 1992-98, ebino-related complications, mainly sepsis and anaemia, were among the leading causes of admission (n = 740) and hospital death (n = 156, case fatality rate = 21.1%, proportional mortality rate = 3.3%). Discouraging the adoption of deeply rooted traditional practices that are potentially hazardous to health should be a public health priority in northern Uganda. This could be done by educating not only the general public, but also traditional healers and community and religious leaders, who could convey the knowledge to their people.

Immune activation in africa is environmentally-driven and is associated with upregulation of CCR5. Italian-Ugandan AIDS Project

BACKGROUND

HIV infection in Africa is associated with immune activation and a cytokine profile that stimulates CCR5 expression. We investigated whether this immune activation is environmentally driven; if a dominant expression of CCR5 could indeed be detected in African individuals; and if R5 HIV strains would be prevalent in this population.

METHODS

Freshly drawn peripheral blood mononuclear cells from HIV-uninfected African and Italian individuals living in rural Africa, from HIV-uninfected Africans and Italians living in Italy, and from HIV-infected African and Italian patients were analysed. Determinations of HIV coreceptor-specific mRNAs and immunophenotype analyses were performed in all samples. Virological analyses included virus isolation and characterization of plasma neutralizing activity.

FINDINGS

Results showed that: immune activation is detected both in Italian and African HIV-uninfected individuals living in Africa but not in African subjects living in Italy; CCR5-specific mRNA is augmented and the surface expression of CCR5 is increased in African compared with Italian residents (CXCR4-specific mRNA is comparable); R5-HIV strains are isolated prevalently from lymphocytes of African HIV-infected patients; and plasma neutralizing activity in HIV-infected African patients is mostly specific for R5 strains.

CONCLUSIONS

Immune activation in African residents is environmentally driven and not genetically predetermined. This immune activation results in a skewing of the CCR5 : CXCR4 ratio which is associated with a prevalent isolation of R5 viruses. These data suggest that the selection of the predominant virus strain within the population could be influenced by an immunologically driven pattern of HIV co receptor expression.

Rotavirus infection among children with diarrhoea in Italy

Despite the absence of a nationwide surveillance system for rotavirus infection, relevant information concerning the epidemiology of this pathogen in Italy can be obtained from hospital-based studies carried out since the early 1980s on patients with acute diarrhoea. A review of more than 50 papers and congress proceedings published in both international and national literature indicates that rotavirus is the most important cause of diarrhoea in Italy among young children requiring hospitalization, with a prevalence ranging from approximately 20% to 40% in different studies. Infection is predominant among children aged 6-24 months, although cases are also common in younger children and in children 2-3 y of age. Despite differences among studies in geographical area, years and age group under investigation, an increase in rotavirus cases is consistently reported in the winter months, with a peak in February through April. Although a few studies have been conducted in non-hospitalized patients, rotavirus infection is significantly less frequent among outpatients with enteritis than among inpatients. Most circulating rotavirus strains typed from 1981 to 1992 belong to serotype 1 and, to a lesser extent, 4. However, untypable rotavirus strains have been found in these years, with prevalences up to 27%, suggesting a possible spread of non-serotype 1 through 4 strains.

Immune activation in HIV-infected African individuals. Italian-Ugandan AIDS cooperation program

OBJECTIVE

Immune activation induced by chronic infections, dietary limitations, and poor hygienic conditions is suggested to be present in African HIV infection and is at the basis of the hypothesis that HIV infection in Africa could be prevalently associated with immunopathogenetic mechanisms. Very limited data are nevertheless available supporting this theory, and in particular no data are reported on functional and phenotypic analyses performed on fresh peripheral blood mononuclear cells (PBMC) of African HIV-infected patients living in Africa.

DESIGN

Immunological and virological parameters were analysed in fresh PBMC of HIV-infected African and Italian patients with advanced HIV disease and comparable CD4 and CD8 counts, sex, and age. Both functional (antigen- and mitogen-stimulated cytokine production) and phenotypic (activation markers; markers preferentially expressed by T helper (Th) type 2 cells or by memory and naive cells) analyses were performed. Results were compared with those of HIV-seronegative African and Italian controls. HIV plasma viraemia was analysed by competitive polymerase chain reaction (PCR) and branched DNA techniques.

RESULTS

(1) The production of mitogen-stimulated IFN-gamma and TNF-alpha as well as the production of env peptide-stimulated IFN-gamma, TNF-alpha, and IL-10 are increased in African HIV infection; (2) the expression of activation and Th2-associated markers is augmented in African HIV infection as is the memory/naive ratio; (3) mitogen-stimulated IFN-gamma and IL-10 production, as well as the expression of activation and Th2-associated markers and the memory/naive ratio, are augmented in African compared with Italian controls; and (4) plasma viraemia is reduced in African compared with Italian HIV-infected individuals.

CONCLUSIONS

These results, which are the first to be reported on fresh material from African HIV-infected patients living in Africa, indicate that HIV disease is associated with an abnormal immune hyperactivation and may be accompanied in these patients by lower loads of virus, and show that such activation is present even in HIV-seronegative controls.

Immunological activation markers in the serum of African and European HIV-seropositive and seronegative individuals

OBJECTIVE

The concentration of type 1 and type 2 cytokines and fibroblast-associated apoptosis-1 soluble receptor (sAPO-1/Fas) was analysed in the sera of Ugandan and Italian HIV-1-seropositive and seronegative individuals. The data were compared to determine whether the immunological status of these groups was different.

METHODS

Sixty-seven Ugandan and 30 Italian HIV-positive patients were analysed and stratified according to CD4 counts (group 1, > 500 x 10(6)/l; group 2, 200-500 x 10(6)/l; group 3, < 200 x 10(6)/l). Sera from 15 Ugandan and 11 Italian HIV-negative blood donors were also analysed. Serum concentration of type 1 cytokines [interleukin (IL)-2, IL-12, and interferon (IFN)-gamma] and type 2 cytokines (IL-4 and IL-10), and sAPO-1/Fas were measured by enzyme-linked immunosorbent assay.

RESULTS

Serum levels of IL-2, IFN-gamma and IL-10 but not of IL-4 and IL-12, were elevated in HIV-positive group 1 and 2 Africans compared with HIV-positive Italian individuals. IL-4 was mildly augmented in HIV-positive group 3 African patients. Serum concentration of sAPO-1/Fas was reduced in HIV-positive Africans compared with HIV-positive Italian individuals. Finally, serum levels of IL-2 and IL-10 were increased and sAPO-1/Fas reduced when sera of HIV-negative African healthy controls were compared with their Italian counterparts. The ratio of type 1/type 2 cytokines was roughly 1.0 in HIV-negative African controls, and much greater than 1.0 in HIV-negative Italian controls.

CONCLUSIONS

These preliminary findings indicate that immune activation is present in African HIV infection. Furthermore, these data raise the possibility that abnormal immune activation and increased susceptibility to antigen-induced cell death is present even in HIV-negative African controls.

[Public health surveillance: historical origin, methods, and assessment]

In the last three decades disease surveillance has grown into a complete discipline, quite distinct from epidemiology. This expansion into a separate scientific area within public health has not been accompanied by parallel growth in the literature about its principles and methods. The development of the fundamental concepts of surveillance systems provides a basis on which to build a better understanding of the subject. In addition, the concepts have practical value as they can be used in designing new systems as well as understanding or evaluating currently operating systems. This article reviews the principles of surveillance, beginning with an historical survey of the roots and evolution of surveillance, and discusses the goals of the public health surveillance. Methods for data collection, data analysis, interpretation, and dissemination are then presented, together with proposed procedures for evaluating and improving a surveillance system. Finally, some points to be considered in establishing a new surveillance system are presented.

Public health surveillance: historical origins, methods and evaluation

In the last three decades, disease surveillance has grown into a complete discipline, quite distinct from epidemiology. This expansion into a separate scientific area within public health has not been accompanied by parallel growth in the literature about its principles and methods. The development of the fundamental concepts of surveillance systems provides a basis on which to build a better understanding of the subject. In addition, the concepts have practical value as they can be used in designing new systems as well as understanding or evaluating currently operating systems. This article reviews the principles of surveillance, beginning with a historical survey of the roots and evolution of surveillance, and discusses the goals of public health surveillance. Methods for data collection, data analysis, interpretation, and dissemination are presented, together with proposed procedures for evaluating and improving a surveillance system. Finally, some points to be considered in establishing a new surveillance system are presented.