High HIV prevalence in a southern semi-rural area of Mozambique: a community-based survey.

BACKGROUND: Southern African countries have borne the brunt of the HIV/AIDS pandemic. Monitoring epidemiological dynamics is critical to identify the populations at greatest risk of infection and to guide control strategies. METHODS: A cross-sectional community-based study to determine age- and sex-specific HIV prevalence among individuals aged 18-47 years was carried out in Manhiça, southern Mozambique. Participants were randomly selected from the demographic surveillance system in place in the area and voluntary HIV counselling and testing were offered at home. In addition, HIV prevalence estimates from the antenatal clinic (ANC) were collected prospectively. RESULTS: A total of 839 individuals were invited to participate in the study. Of these, 722 were recruited (50.7% women). The overall HIV prevalence in the community was 39.9% [95% confidence interval (CI) 35.9-43.8%]. By age, the prevalence was 23.2% (95% CI 17.9-28.6%) in individuals aged 18-27 years, 41.2% (95% CI 35.6-48.3%) in those aged 28-37 years and 44.8% (95% CI 38.4-51.2%) in those aged 38-47 years. HIV prevalence was higher among women than men in all age groups. The overall HIV prevalence estimate for women in the community (43.1%; 95% CI 37.6-48.5%) was 1.4 times higher than that for those attending the ANC (29.4%; 95% CI 26.7-32.0%). CONCLUSIONS: The high HIV prevalence found in this region suggests that the epidemic is in a mature stable phase. The lower rates in the ANC than in the community suggest that ANC evaluations may underestimate community HIV prevalence. Resources to monitor HIV infection dynamics are needed to guide targeted control strategies in countries in which the epidemic exacts the greatest toll.

Estimating the vaccine-preventable burden of hospitalized pneumonia among young Mozambican children.

Polysaccharide-protein conjugate vaccines against Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae have proven efficacy against radiologically confirmed pneumonia. Measurement of pneumonia incidence provides a platform to estimate of the vaccine-preventable burden. Over 24 months, we conducted surveillance for radiologically confirmed severe pneumonia episodes among children <2 years of age admitted to a rural hospital in Manhiça, southern Mozambique. Study children were tested for HIV during the second year of surveillance. Severe pneumonia accounted for 15% of 5132 hospital admissions and 32% of in-hospital mortality among children <2 years of age. Also, 43% of chest radiographs were interpreted as radiologically confirmed pneumonia. HIV-infection was associated with 81% of fatal pneumonia episodes among children tested for HIV. The minimum incidence rate of radiologically confirmed pneumonia requiring hospitalization was 19 episodes/1000 child-years. Incidence rates among HIV-infected children were 9.3-19.0-fold higher than HIV-uninfected. Introduction of Hib and pneumococcal conjugate vaccines would have a substantial impact on pneumonia hospitalizations among African children if vaccine effects are similar to those observed in clinical trials.

Serotype-specific pneumococcal disease may be influenced by mannose-binding lectin deficiency.

Previous studies of the association between the mannose-binding lectin pathway deficiencies and invasive pneumococcal disease are inconclusive. Invasiveness of Streptococcus pneumoniae is dependent on serotype. We aimed to determine the association between invasive pneumococcal disease and MBL2 and MASP2 genetic variants, regarding serotype distribution. A hospital-based case-control study was conducted in children admitted to hospital in rural Mozambique in June 2002-November 2003. The study included children admitted to hospital with invasive pneumococcal disease, in whom S. pneumoniae was isolated from blood and subsequently serotyped. Sequence-based typing analysis of amplicons covering the polymorphic regions of MASP2 (exon 3) and MBL2 (promoter and exon 1) was performed. An overall high frequency of MBL2 genotypes associated with low serum levels of MBL (43%) was found. Carriers of MBL-deficient genotypes were associated with invasive pneumococcal disease produced by low-invasive serotypes (OR 5.55, 95% CI 1.4-21.9; p = 0.01). Our data suggest that susceptibility to pneumococcal disease among MBL-deficient patients may be influenced by serotype invasiveness. Type-specific capsular serotype of S. pneumoniae would need to be taken into account in further genetic association studies of invasive pneumococcal disease.

Surveillance of acute bacterial meningitis among children admitted to a district hospital in rural Mozambique.

BACKGROUND: Acute bacterial meningitis (ABM) remains an important cause of mortality among African children. Epidemiologic data with regard to ABM infection are necessary for prioritizing public health interventions. METHODS: We strengthened hospital-based surveillance of ABM among children admitted to Manhiça District Hospital (Maputo, Mozambique). Cerebrospinal fluid (CSF) samples were collected from children admitted to the hospital who met clinical criteria of ABM. Laboratory determinations were performed. Clinical information and outcome of cases were recorded. RESULTS: During the first 12 months of surveillance, which began in January 2006, CSF samples were collected from 642 children <15 years of age with suspected meningitis (18% of all pediatric patients admitted to the hospital during that time). ABM was confirmed in 43 (7%) of the 642 cases. Haemophilus influenzae type b (Hib) (14 cases), pneumococcus (9 cases), and meningococcus (7 cases) represented approximately 70% of confirmed cases. Four of the 9 pneumococci were serotypes covered by the 7-valent pneumococcal conjugate vaccine. The case fatality rate among patients with ABM was 24% (8 of 33 with known outcome); an additional 8 patients left the hospital before discharge. The incidence of ABM was 85 per 100,000 population, which peaked at 2-12 months of age at 1078 cases per 100,000 population. All 9 pneumococci isolates were susceptible to chloramphenicol, and 8 were susceptible to penicillin (the additional 1 had intermediate resistance). For the 10 Hib isolates tested, only 1 was susceptible to chloramphenicol, and 5 were susceptible to ampicillin. CONCLUSION: These data reinforce the importance of ABM as a cause of hospital admission and death in rural sub-Saharan Africa. Most observed ABM cases could have been prevented by current pneumococcal and Hib conjugate vaccines.