Efficacy of primary chemoprophylaxis against Pneumocystis carinii pneumonia during the first year of life in infants infected with human immunodeficiency virus type 1

The expanding role of co-trimoxazole in developing countries

Co-trimoxazole is an inexpensive, broad-spectrum antimicrobial drug that is widely used in developing countries. Before antiretroviral therapy (ART) scale-up, co-trimoxazole prophylaxis reduced morbidity and mortality in adults and children with HIV by preventing bacterial infections, diarrhoea, malaria, and Pneumocystis jirovecii pneumonia, despite high levels of microbial resistance. Co-trimoxazole prophylaxis reduces early mortality by 58% (95% CI 39-71) in adults starting ART. Co-trimoxazole provides ongoing protection against malaria and non-malaria infections after immune reconstitution in ART-treated individuals in sub-Saharan Africa, leading to a change in WHO guidelines, which now recommend long-term co-trimoxazole prophylaxis for adults and children in settings with a high prevalence of malaria or severe bacterial infections. Co-trimoxazole prophylaxis is recommended for HIV-exposed infants from age 4-6 weeks; however, the risks and benefits of co-trimoxazole during infancy are unclear. Co-trimoxazole prophylaxis reduces anaemia and improves growth in children with HIV, possibly by reducing inflammation, either through direct immunomodulatory activity or through effects on the intestinal microbiota leading to reduced microbial translocation. Ongoing trials are now assessing the ability of adjunctive co-trimoxazole to reduce mortality in children after severe anaemia or severe acute malnutrition. In this Review, we discuss the mechanisms of action, benefits and risks, and clinical trials of co-trimoxazole in developing countries.

The rate of serious bacterial infections among HIV-infected children with immune reconstitution who have discontinued opportunistic infection prophylaxis

OBJECTIVE

Receipt of highly active antiretroviral therapy is associated with a decrease in the incidence of opportunistic infections (OIs) among HIV-infected adults. The goal of Pediatric AIDS Clinical Trials Group protocol 1008 was to evaluate prospectively the incidence of serious bacterial infections (SBIs) and other OIs after discontinuation of OI and/or Pneumocystis jiroveci pneumonia (PCP) prophylaxis among HIV-infected pediatric subjects who experienced immune reconstitution while receiving stable antiretroviral therapy.

METHODS

HIV-infected children and adolescents, 2 to 21 years of age, who had received OI and/or PCP prophylaxis for > or =6 months were enrolled if they had sustained responses (>16 weeks before study entry) to antiretroviral therapy, with CD4+ cell percentages of > or =20% for patients >6 years of age or > or =25% for patients 2 to 6 years of age. Prophylaxis was discontinued at entry. To identify whether any correlation existed between functional immune reconstitution and protection from OIs, subjects were immunized with the hepatitis A virus vaccine. The association between the humoral immune response and the likelihood of developing an OI was evaluated.

RESULTS

A total of 235 HIV-infected subjects from 43 participating sites had a median follow-up period of 132 weeks, yielding 547 person-years of observation. Twenty SBIs were observed among 19 subjects, resulting in an incidence rate of 3.66 SBIs per 100 person-years (95% confidence interval: 2.24-5.66 SBIs per 100 person-years). Sixteen of the events were presumed bacterial pneumonia, with 4 proven SBIs. One participant experienced 2 separate pneumonia episodes, of presumed bacterial cause. Ten subjects who developed SBIs had baseline CD4+ cell counts of > or =750 cells per mm3, and 15 had CD4+ cell percentages of > or =25% at the time of their SBIs. Two subjects died as a result of non-SBI-related causes. There were no statistically significant differences in changes over time in CD4+ cell counts or CD4+ cell percentages between subjects who experienced primary end points and those who did not. There was no evidence that baseline protease inhibitor use, gender, race/ethnicity, age, or CD4+ cell count or percentage affected the time to development of a SBI.

CONCLUSIONS

OI or PCP prophylaxis can be withdrawn safely for HIV-infected pediatric patients who experience CD4+ cell recovery while receiving stable antiretroviral therapy. More studies are needed to assess the association between antibody responses to neoantigens and the development of SBIs.

Prevalence of dihydropteroate synthase mutants in HIV-infected South African children with Pneumocystis jiroveci pneumonia

BACKGROUND

Pneumocystis jiroveci (formerly Pneumocystis carinii) pneumonia (PCP) is a major cause of mortality in human immunodeficiency virus (HIV)-infected infants in Africa, but the prevalence of mutations in the gene encoding dihydropteroate synthase (DHPS) in isolates from Africa has not been reported.

METHODS

This study investigated the prevalence of DHPS mutations in P. jiroveci isolates from South African HIV-infected children with PCP by amplifying DNA using 2 different polymerase chain reactions.

RESULTS

P. jiroveci DNA from 30 respiratory specimens was amplified; 26 specimens (86.7%) contained wild-type DHPS alleles. Of the 4 samples (13.3%) with DHPS mutations, 2 contained a homogenous population with single DHPS mutations, 1 contained a homogenous population with 2 DHPS mutations, and the fourth contained a heterogenous population of organisms with both wild-type and single-mutant DHPS genotypes. Only 1 child was receiving trimethoprim-sulphamethoxazole (TMP-SMZ) prophylaxis; this patient was infected with wild-type P. jiroveci. The mortality rate (overall, 20 [66.7%] of 30 children) was not significantly different between children infected with wild-type P. jiroveci (17 [65.4%] of 26) and those infected with mutant strains (3 [75%] of 4; P=.8).

CONCLUSIONS

DHPS mutations are uncommon in P. jiroveci isolates from South Africa. However, increasing use of TMP-SMZ prophylaxis may result in widespread development of mutations.

Pneumocystoses graves en réanimation pédiatrique étude rétrospective 1980–2002

OBJECTIVE

The objective of this study was to ascertain the clinical and epidemiological characteristics of Pneumocystis carinii pneumonia (PCP) cases admitted to the Pediatric Intensive Care Unit (PICU).

PATIENTS AND METHODS

A retrospective study was carried out for the 10 PCP cases admitted to the PICU from 1980 to 2002. The variables studied were: age, sex, PRISM, underlying diseases, immunological status, clinical manifestations, radiology, response to therapy and clinical follow up.

RESULTS

Age of the patients varied between 5 months and 15 years and 4 months and there were 7 females and 3 males. Underlying diseases included: AIDS (3 cases), renal transplant (2 cases), West syndrome (1 case), cancer (4 cases). All presented an acute respiratory failure and 8/10 needed mechanical ventilation (mean duration: 14 days). All were treated by trimethoprim-sulfamethoxazole and 6/10 received steroids. Only one child died.

CONCLUSION

PCP is rare and affects mainly immunocompromised children who exhibit ARDS. Steroids treatment is now considered as an useful therapeutic adjuvant. A preventive treatment should be administered to children at risk.

Opportunistic infections and other clinical manifestations of HIV disease in children

As the decade draws to a close, physicians can be cautiously optimistic about the prevention and treatment of opportunistic infections in children with HIV disease. As more children receive therapy with powerful antiretroviral regimens, fewer are likely to be at risk for opportunistic pathogens. The widespread use of protease inhibitor combination therapies has already resulted in a dramatic decrease in morbidity and mortality in the population of HIV-infected adults. The same effect has been seen at pediatric care centers throughout the United States. Clinicians caring for HIV-infected children are now considering the safety of discontinuing prophylactic therapies for children with sustained immunologic improvement on antiretroviral therapy. For children who remain at risk, prophylactic regimens for PCP and MAC have been shown to decrease the risk for these infections. Preventive regimens for several other opportunistic infections are also available. The understanding of the pathogenesis of HIV and many of the opportunistic pathogens has led to the development of a variety of efficacious therapies for these infections. Despite these advances, physicians can anticipate that HIV-infected children will continue to develop opportunistic infections and other related complications. Some children fail to respond to antiretroviral therapies, whereas others are unable to tolerate the complex medication regimens. Prophylactic therapies are not 100% protective and, despite improved treatments, few opportunistic infections are cured. Most require lifelong maintenance therapy in the absence of immune reconstitution. Drug interactions, complex dosing schedules, adverse side effects, and high costs further limit the efficacy of these therapies. The prophylaxis, diagnosis, and treatment of opportunistic infections are likely to remain integral components of HIV care for the near and distant future.

Pneumocystis carinii pneumonia prophylaxis and early clinical manifestations of severe perinatal human immunodeficiency virus type 1 infection. Northern California Pediatric HIV Consortium

BACKGROUND

Some children with perinatal HIV infection develop early progression to severe symptoms (Category C) within the first 4 years of life. Prophylactic therapy with trimethoprim-sulfamethoxazole (TMP/SMX) may affect progression by decreasing the incidence of Pneumocystis carinii pneumonia (PCP).

METHODS

HIV progression to Category C in the first 3 years of life was retrospectively analyzed in a population-based cohort of children with perinatal HIV infection followed for > or = 3 years from birth. Time to development of Category C and clinical patterns of new Category C diagnoses were examined in relation to patterns of PCP prophylaxis before diagnosis.

RESULTS

Fifty-eight of 147 children developed 67 initial category C diseases by 3 years of age: PCP (n=24), encephalopathy (n=22), other opportunistic infections (n=19) and wasting (n=2). Before diagnosis therapy included TMP/ SMX and zidovudine (ZDV) (n=11), TMP/SMX alone (n=7), ZDV alone (n=1) and neither (n= 39). The probability of developing a Category C diagnosis after 2 years was significantly lower among children who received TMP/SMX compared with those who did not (29%, TMP/SMX vs. 45%, no TMP/SMX; 30%, TMP and ZDV vs. 45%, no therapy; P < 0.01). The frequency of PCP was significantly lower and that of HIV encephalopathy was significantly higher among children receiving TMP/SMX +/- ZDV before Category C diagnosis than among children receiving neither.

CONCLUSION

In this study PCP prophylaxis was associated with longer time to Category C diagnoses in the first 3 years of life. This association was related to a decreased incidence of PCP and an increased incidence of encephalopathy as the first Category C diagnosis among children who received TMP/SMX.

Pediatric HIV infection

Developments in the prevention and treatment of HIV infection in pregnant women and their children are encouraging. Perinatal ZDV therapy can reduce the maternal-infant transmission rate by two thirds in select populations. New therapies and the development of diagnostic assays to monitor HIV viral burden have renewed hope that, by aggressively controlling viremia, the progressive immunodeficiency can be delayed or even prevented. The general pediatric approach of preventing illnesses through aggressive vaccination and education policies must be actively incorporated into an approach to this epidemic. Success in controlling the pediatric HIV epidemic requires a concerted, coordinated effort by public policy makers, health care providers, basic science researchers, and those who are HIV-infected.

Long-term administration of aerosolized pentamidine as primary prophylaxis against Pneumocystis carinii pneumonia in infants and children with symptomatic human immunodeficiency virus infection. The Italian Pediatric Collaborative Study Group on Pentamidine

SUMMARY

We assessed the long-term feasibility, safety, and tolerability of two regimens of aerosolized pentamidine (AP) as primary prophylaxis of Pneumocystis carinii pneumonia (PCP) in a large sample of infants and children with symptomatic HIV infection in 21 pediatric departments. One hundred forty children were assigned to receive 60 mg every 2 weeks (n = 60) or 120 mg every 4 weeks (n = 80) of AP, delivered by the ultrasonic nebulizer Fisoneb under the supervision of trained personnel. Children underwent monthly clinical and laboratory controls for toxicity and/or development of PCP for an 18-month period. Baseline characteristics were similar in the two treatment groups. The median age was 5 years. The feasibility of administering AP was excellent in 84 (60 percent) and good in 38 (27 percent) children. All children aged <2 years showed excellent or good feasibility. Long-term compliance was good with both regimens. No child had severe adverse reactions requiring discontinuation of the treatment. Cough, sneezing, and bronchospasm were the most frequent side effects occurring, respectively, in 12, 3.7, and 0.7 percent of the 60-mg treatments and in 19.1, 6. 1, and 2.8 percent of 120-mg treatments (p < 0.05). Their incidence was not different in children younger or older than 5 years. Two episodes of PCP were observed in the group receiving 120 mg monthly, whereas none of the 60 children in the biweekly schedule had PCP (p = 0.20). AP can be safely administered to very young children with few adverse side effects.

Shortened survival in infants vertically infected with human immunodeficiency virus with elevated p24 antigenemia

OBJECTIVE

To determine whether the amount of p24 antigenemia in the first 6 months of life is a predictor of survival in children infected vertically with human immunodeficiency virus type 1.

METHODS

A retrospective study of vertically infected infants and children who were followed prospectively from early infancy and who had quantitation of plasma p24 antigen concentration in the first 6 months of life. Infants were first stratified by duration of survival as infants who died before 2 years of age (short-term survivors) and infants who survived to 2 years of age (intermediate-term survivors). The median p24 antigen concentration and the proportion of infants in each group with high concentrations of antigen were compared. Analyses with and excluding all p24 determinations made after the use of antiretroviral agents were compared Kaplan-Meier product limit analysis was used to compare survival in infants with low and high antigenemia during the first 6 months of life.

RESULTS

The median p24 antigen concentration in 15 short-term survivors was 228 pg/ml, compared with 14 pg/ml in 26 intermediate-term survivors (p < 0.05). The proportion of children with > 100 pg/ml of p24 was higher in short-term than in intermediate-term survivors (p = 0.01). Survival to 2 years of age in infants in whom all p24 antigen values during the first 6 months of life were 100 pg/ml or less was 91%, in comparison with 39% in infants with values greater than 100 pg/ml (p = 0.0017).

CONCLUSIONS

Elevated p24 antigenemia in the first 6 months of life is associated with shorter survival and may be a useful predictor of outcome.